# Running on water



## oldenstar

Motor Caravan magazine has done a review this month on a hydrogen kit, supplied by Towtal, which has improved the mpg of a new 2.5 Transit by 38 per cent, no less.

Unfortunately their electric box of tricks which tells the engine fuelling system how to work with the system does not yet work with the new Sevel vans (all to do with their five wire Lamda sensors, it seems).
Towtal are working on a unit at the moment for these vans.

So the scepticism shown on previous threads on this subject may have been misplaced. The review concludes that this kit could pay for itself in under two years.

They achieved 50% increases in mpg with a Discovery and a Kia Sorrento when used as towcars.

Paul


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## mickyc

Man the trenches.......................



INCOMING !!!!!!!


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## cabby

did it give a price on this conversion

cabby


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## geraldandannie

cabby said:


> did it give a price on this conversion


"Expected to be around £695"

Gerald


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## geraldandannie

Previous threads :: here :: and :: here ::

Happy reading!

Gerald


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## 107088

I feel this is obviously clear cut and must be true, after all, no manufacturer would spend 120 million pound developing a new vehicle and fail to improve its fuel ecomony by up to 38%....I mean, what would the point be?

I believe it, I say yay, and hip hoorah. 





Piffle thats what it is....why flog the thing to joe public, when the vehicle makers would be climbing all over you just to be able to say..

Hey look the new transit, now over 40% more fuel efficient.

No transport manager would be able to refuse.


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## geraldandannie

I had a fascinating read of those previous 2 threads last night. We seemed to have an engine scientist (GBrapido) who states that it does work, bluepirate who kept shouting that they had a couple of coffee jars under the bonnet WHICH GAVE HER 29.9% IMPROVEMENT, SO WHY DIDN'T ANYONE BELIEVE HER, ALL YOU NEED IS FAITH, a load of sceptics, and a couple of fence sitters.

Strange that the only person that had actually done it outside a lab (bluepirate) was a farmer who couldn't come on the forum because he was too busy with the harvest, and yet had found time to convert his own van, and spends most of the winter in Portugal. Doesn't sound like any farmer I know.

I must admit to being a little sceptical myself, for Bandy's reasoning above. More, that someone can throw a couple of coffee jars under the bonnet and GIVE ... sorry, give 29.9% improvement.

But equally strange is that Towtal are featured in the magazine as installers of the thing. Sounds like they couldn't get it working properly on the van they used, but quoted figures for a Discovery TDS and a Kia Sorrento. Now, to me, if I had a product like that, the first thing I'd develop it for would be the biggest market i.e. White Van Man, and the Fiat Ducato.

So, I'm open-minded at the moment, but would want to see _real_ figures, independently-obtained, for a real installation on a real van. Savings of £380 year (quoted) sound interesting.

Gerald


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## artona

Hi

I have seen the set up at Towtal and it looks very professionally built although I did not see theirs working. 

I have seen working models though in Essex at an MOT station who are working on it. They had fitted three test models, one to a motorbike which they say did not improve economy but did make the bike go like a jet propelled vehicle. The next was to a dirty old lorry that had failed the emissions and they claimed it sorted the emissions out so well it went to below the London emissions tests and the final one, the most successful in terms of increased miles per gallon to a Peurgeot 406.

The story I hear is the technique was invented years ago but stifled by fuel companies


stew


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## Boff

Hi,

even if this claim make me physicist's hair stand on end, I would be willing to give them the benefit of the doubt. However, only if they support their claims by sound _evidence_.

So, should they give their converted Transit, or whatever, to an approved, independent organization to run it through a full EU fuel efficiency test cycle, confirming their claim, then I will believe it. Not earlier.

If not, then: If your bank clerk comes to you and offers you an asset with a 38% interest rate p.a., and no risk at all, only a one-time fee of 700 quid, would you believe him?

Best Regards,
Gerhard


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## 115737

Boff said:


> If not, then: If your bank clerk comes to you and offers you an asset with a 38% interest rate p.a., and no risk at all, only a one-time fee of 700 quid, would you believe him?


Yes, because his advice, and that of his institution is regulated by the FSA. and as such will have been proven to be risk free or face the wrath of the FSA


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## Zebedee

I'm with Boff here - all the way!!   

We have Conspiracy Theory on the one hand, and "Water into wine" on the other. :roll: :roll: 

The truth is probably somewhere in between, but most certainly needs some rigorous and very carefully monitored independent testing to discover exactly where!!


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## davesport

I don't wish to sound like a broken record......but I'm with Boff & Zeb on this one. I keep an open mind about most things including this. But until the results are analysed & proven in an independent & scientific manner I'm sticking with methane 

D.


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## Boff

Hi!



Zebedee said:


> The truth is probably somewhere in between, but most certainly needs some rigorous and very carefully monitored independent testing to discover exactly where!!


Well, I am quite sure how this will end: Somebody will do the independent test, and find out that there is no effect at all or, even more likely, an adverse effect. Then the company will publish a longish statement why their thing does not work under standardised test conditions, but will certainly work under all other conditions. :?

In the end it will turn out that the truth is not in between "Conspiracy" and "Water into wine", but somewhere in between superstition and deliberate fraud... 

Best Regards,
Gerhard


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## Zebedee

Hi Gerhard

I shall not be at all surprised if your scenario is played out to the letter! 8O :roll: 

Cheers


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## badger

Must be true......I've just heard that water has gone up to £1.30 per litre :roll:


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## Zebedee

badger said:


> Must be true......I've just heard that water has gone up to £1.30 per litre :roll:


Shot yourself in the foot there Badger (Tee hee!)!! :lol: :lol: :lol: :lol:

If you buy it as Spring Water it costs a lot more than that - or so I'm told.

I certainly won't pay for water while the taps are still running, especially when you get a notice on the label saying, "This water has percolated through the rocks of Evi** for four million years. *Consume by September 5th 2009*". :? :? :roll:

_(Sorry - strayed off topic again.)_


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## duxdeluxe

I would like to see some of the science behind this and - like everyone else - see some real testing results.

As the saying goes, if it sounds too good to be true, then it probably is.

As for "being suppressed by the fuel companies" - if they did that then why are they all still spending BILLIONS on research into alternative fuels and making engines more efficient when they have a 600 quid solution? I'm not doubting Artona's words but in the light of day it doesn't make a lot of sense - everyone is falling over themselves to promote their company as being green and environmentally friendly and a new technology would be a killer advantage in a very competitive business.

As an aside, I am currently working with one the oil majors on a project that will *reduce* their sales of a type of oil. Not big beans, I know, but an indication of the thinking. Everyone hates big oil and they really want to be seen to be warm and cuddly - just look at some of their nauseating "green" adverts.


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## oldenstar

> Yes, because his advice, and that of his institution is regulated by the FSA. and as such will have been proven to be risk free or face the wrath of the FSA


If I may say so that is a particularly unfortunate analogy at present given that the teeth of the FSA have proven to be less effective than those of my old Gran, who had none.

As to this topic, and as someone who was busy concentrating on other things during physics lessons, I feel that the problem is due to the fact that the subject is water.

If we forget it is water, and just think of 2 parts hydrogen and 1 part oxygen it seems less far fetched.

I have a totally open mind, but hope that it does prove to work because it would benefit everyone in the long term.

Paul


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## 115737

oldenstar said:


> Yes, because his advice, and that of his institution is regulated by the FSA. and as such will have been proven to be risk free or face the wrath of the FSA
> 
> 
> 
> If I may say so that is a particularly unfortunate analogy at present given that the teeth of the FSA have proven to be less effective than those of my old Gran, who had none.
> 
> As to this topic, and as someone who was busy concentrating on other things during physics lessons, I feel that the problem is due to the fact that the subject is water.
> 
> If we forget it is water, and just think of 2 parts hydrogen and 1 part oxygen it seems less far fetched.
> 
> I have a totally open mind, but hope that it does prove to work because it would benefit everyone in the long term.
> 
> Paul
Click to expand...

True, but at least if it turns out that they lied to me and mis-sold me some kind of investment opportunity, I can pursue it legally. These dodgy "Well, we think it works because it felt different when we tried, and my mate Baz reckoned it was better too" types of things aren't quite the same.

The thing about water is that it is a *very* stable compound, it doesn't react with very much and to make it do anything much at all, large amounts of energy are usually required. Breaking the bonds to make hydrogen, the process of electrolysis, requires more energy than you get from burning the hydrogen afterwards, which is mostly the reason why we don't have hydrogen engines that just run on sea-water.

This is why water is so abundant, it just sort of sits around not really doing very much.


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## johng1974

> This is why water is so abundant, it just sort of sits around not really doing very much.


 

I miss Blupirate a bit..


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## 115737

johng1974 said:


> This is why water is so abundant, it just sort of sits around not really doing very much.
> 
> 
> 
> 
> 
> I miss Blupirate a bit..
Click to expand...

What's a Blupirate?


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## 104101

MalphasWats said:


> Boff said:
> 
> 
> 
> If not, then: If your bank clerk comes to you and offers you an asset with a 38% interest rate p.a., and no risk at all, only a one-time fee of 700 quid, would you believe him?
> 
> 
> 
> Yes, because his advice, and that of his institution is regulated by the FSA. and as such will have been proven to be risk free or face the wrath of the FSA
Click to expand...

You wouldn't like to review this, in the light of current events?


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## 115737

brayn said:


> You wouldn't like to review this, in the light of current events?


my point is that the Snake Oil market is unregulated, whilst the financial market (however wafty, or wobbly) is.


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## johng1974

this was an earlier posting on HHO , Malphas..

here


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## 115737

johng1974 said:


> this was an earlier posting on HHO , Malphas..
> 
> here


heeheehee.

I hope it's all powered with oxygen-free directional copper cables, for maximum signal clarity.


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## duxdeluxe

After you have finished running your motorhome on water then you might like to relax with some Chateau Petrus or maybe a Lafite Rothschild - see how to get it for Eur 3.99 a bottle

http://www.telegraph.co.uk/news/new...to-fine-wine-in-30-minutes-says-inventor.html

My order is in and Mrs Deluxe is looking forward to spending the next year in luxurious oblivion - not!

And if you want water to run your 'van there is plenty of it here in the Philippines, we are in the middle of a Typhoon, again! Got stuck in Hong Kong in a typhoon (not allowed out of hotel) and then cancelled Taiwan for another one, thought I was safe after three days deing drenched in Japan (yet another) and then landed on one wheel (in a 747) here this afternoon in zero visibility and wind that was blowing dogs off chains.

Sorry about that but am beginning to suspect that the wind and rain gods follow me around. Every time we have been away in the van this year it has blown old boots or been wet or both!


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## 110747

next thing you'll all be telling the drag racers out there that nitrous oxide doesn't work either.


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## Boff

johng1974 said:


> this was an earlier posting on HHO , Malphas..
> 
> here


Oops, have missed something. That is the unfortunate part of going on vacation in your motorhome.

Now I have read it...



It took some time to crawl up again from under the table afterwards. :wink:

Now I see that my example with the bank investment was a bit far-fetched. Because it was maybe not very realistic, but at least _plausible_. This here is not.



oldenstar said:


> If we forget it is water, and just think of 2 parts hydrogen and 1 part oxygen it seems less far fetched.


That brings it precisely to the point. It is absolutely true that water consists of two parts hydrogen and 1 part oxygen. However, they form a _compound_. It is even true that when forming that compound, a significant amount of energy is released. Not without reason is a mixture of 2 parts hydrogen gas with 1 part oxygen gas called 'detonating gas'.

To break up this bond, exactly the same amount of energy that comes out when creating it, has to be invested. In theory, that is, in practice it is much more becauses you always have losses.

Now it is not my intention to upset any devout believers in "free energy". Neither to convince them, because I know I can't. Nobody can. But I am sure that most members here have retained a healthy scepticism. And if at least some of the doubtful will refer to their O-level physics lessons before they part with money (look up under "conservation of energy") for such a hoax, then I have achieved what I wanted.

Best Regards,
Gerhard


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## Zebedee

If it did work Gerhard, I think it would qualify as a perpetual motion machine - in principle anyway!

_"Energy out equals or exceeds energy in"._

There's still a one million quid prize on offer I think, but I reckon the cash is pretty safe! :roll:


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## 115737

GBrapido said:


> next thing you'll all be telling the drag racers out there that nitrous oxide doesn't work either.


Erm, only if they're claiming to have a magic nitrous oxide machine that takes nigtrogen and oxygen from little tanks, glues it together and *then* injects it into the engine, all powered by the engine.

forgetting the chemical problems of hydrogen and oxygen atoms existing alone for any useful amount of time, if you made them in a big factory and put them in a tank before you set off, the extra combustion provided might increase efficiency, who knows, but only because you didn't expend the same energy making it in the first place.

Thermodynamics has some fairly immutable laws*

-Mike

*a couple of episodes of star trek notwithstanding.


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## duxdeluxe

GBrapido said:


> next thing you'll all be telling the drag racers out there that nitrous oxide doesn't work either.


I was not doubting the science behind this and certainly not qualified to doubt the theory. In fact, I followed your posts on the subject on other threads with increasing fascination and appreciation of an obvious expert who puts his point across in a well informed, easy to understand and above all well balanced way. Many thanks from most of us for that. that is what is great about these forums.

Yes, nitrous works. Yes, water injection works (didn't they use this in WW2?) etc etc.

However, as you say yourself, there are many offerings that really don't bear scrutiny and as I said in an earlier post we all need be convinced. Working in the oil business, I am firmly in the "if it sounds too good to be true, then it is too good to be true" camp. The missing link here (no reference to the undersigned here) is actually turning theory into practive in a cost effective manner.

Now please tell me that I can convert my chateau pis de chat into something drinkable - I have a whole garage full of the stuff. Maybe I should find a way of converting it into biodiesel instead. :wink: :wink:

Also, will someone pleeease stop it raining here.


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## 110747

its not about thermodynamics. its chemistry.

The fuel you burn is not burned at all well.

the energy available in the fuel is simply not released in the most efficient way.

the Carnot efficiency of your engine is probably as low as 30%.

the production of hydrogen and oxygen by elecrolysis is not magic.

both exist quite happily on their own, bottled oxygen is used in many places.

bottled hydrogen is a bit rarer but is getting more widespread.

the combustion modification through oxygen / hydrogen fumigation is sound and will under the correct conditions improve that combustion process, see rocket motors for a good example.

there are many unknown factors involved with this modification and the study of high speed combustion is still developing.

i will just re-iterate my position.

the science is sound, but be wary of the sellers of the science and what they don't know about what they sell.

and i have no connection at all with anyone selling any of these bolt on products.

i work as a consultant for OEM's. and have carried out independant test work on this technology, but not any products.

again this is a chemical reaction, thermodynamics only counts when the chemistry has started.

energy balance and over unity has nothing to do with it as the conversion of potential energy to useful energy is incredibly innefficent, it is all about increasing the efficency of the combustion process.

anybody who has verifiable evidence that a product does not work, i would seriously like to see it from a professional point of view as i am totally against the scammers who sell the dream based on false claims as it does the real science and development of engines a complete dis- service.

any questions, please ask.

Geoff


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## 115737

Ok, I'm not a scientist or anything, but I do have a good memory...



GBrapido said:


> its not about thermodynamics. its chemistry.


*Everything* is about thermodynamics, energy moving from one form to another, once place to another etc etc, all follows the laws.



GBrapido said:


> The fuel you burn is not burned at all well.
> 
> the energy available in the fuel is simply not released in the most efficient way.
> 
> the Carnot efficiency of your engine is probably as low as 30%.
> 
> the production of hydrogen and oxygen by elecrolysis is not magic.


Indeed, it does however, require energy.



GBrapido said:


> both exist quite happily on their own, bottled oxygen is used in many places.


Not quite, both Oxygen and Hydrogen in their gas forms, bottled industrially exist as O2 and H2, they cannot exist as single unbound atoms for very long as they are very unstable like this, they will combine with themselves if nothing more suitable is available. Again, breaking these bonds takes more energy.



GBrapido said:


> bottled hydrogen is a bit rarer but is getting more widespread.


It is always H2 when in gas, most of our bottled hydrogen is 'mined' and produced with acids and rocks. The world supply of Hydrogen is dwindling because once released, it doesn't stay around for long. I believe NASA has a huge stockpile carefully hoarded over the last half century or so, but you are correct, it is becoming harder to find.



GBrapido said:


> the combustion modification through oxygen / hydrogen fumigation is sound and will under the correct conditions improve that combustion process, see rocket motors for a good example.


Rocket motors have the fuel already broken up into its useful components, the energy has been expended elsewhere, not by the rocket motor itself.



GBrapido said:


> there are many unknown factors involved with this modification and the study of high speed combustion is still developing.


 Probably, but the laws of thermodynamics stand.



GBrapido said:


> i will just re-iterate my position.
> 
> the science is sound, but be wary of the sellers of the science and what they don't know about what they sell.
> 
> and i have no connection at all with anyone selling any of these bolt on products.
> 
> i work as a consultant for OEM's. and have carried out independant test work on this technology, but not any products.
> 
> again this is a chemical reaction, thermodynamics only counts when the chemistry has started.
> 
> energy balance and over unity has nothing to do with it as the conversion of potential energy to useful energy is incredibly innefficent, it is all about increasing the efficency of the combustion process.
> 
> anybody who has verifiable evidence that a product does not work, i would seriously like to see it from a professional point of view as i am totally against the scammers who sell the dream based on false claims as it does the real science and development of engines a complete dis- service.
> 
> any questions, please ask.
> 
> Geoff


Traditional Science is sadly entirely aware of the fact that it is impossible to prove a negative. The burden of proof is of course on the 'Believers' to prove to science that it works, under controlled scientific conditions, over multiple tests. This is unlikely to happen, in much the same way that the perpetual motion machine earlier in the year failed to do much more than just sit motionless in front of millions of people...


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## Boff

GBrapido said:


> its not about thermodynamics. its chemistry.


It is both. Chemistry can only work within the laws of thermodynamics.



GBrapido said:


> the energy available in the fuel is simply not released in the most efficient way.


This is one of the two common misconception that all these superstitions/hoaxes/scams (select whatever you like) are based on. All fuel that enters the engine will either be burned up, or it will inevitably get into the exhaust system. Older or misadjusted engines indeed sometimes suffer from this, as a result the excess fuel can gather in the exhaust manifold until it reaches a sufficient level, then it will spontaneously combust with a quite audible bang, a phenomenon known as (according to my dictionary :wink: ) _afterfire_. Admittedly, if afterfire occurs then this is a clear indication that the engine is not working at maximum efficiency. But then this is a job for a mechanic.



GBrapido said:


> the Carnot efficiency of your engine is probably as low as 30%.


This is true, and it is true thermodynamics. The Carnot efficiency is an upper limit for the efficiency of any thermodynamic process, and it is determined only by the difference in temperature level. Because of this, there is only one way to improve the efficiency of a given engine, and that is by increasing the temperature inside the engine during the combustion cycle. Now modern engines are already designed to operate at maximum technically achievable temperatures, so if you indeed find a way to further increase temperature, you will seriously damage the engine within very short time.



GBrapido said:


> the production of hydrogen and oxygen by elecrolysis is not magic.


No, it is not magic. But just because there is no magic involved, the electrolysis will need much more energy than you will later gain by recombining the two. Actually, if you get back 50% of the invested energy you are very good.



GBrapido said:


> both exist quite happily on their own


As long as you keep them strictly separate, yes. If not, then: BOOOM! See what happened to space-shuttle Challenger.



GBrapido said:


> the combustion modification through oxygen / hydrogen fumigation is sound and will under the correct conditions improve that combustion process


Even if that is so, and even if the engine is not destroyed during the process, the crucial part is not the combustion but the _production_ of hydrogen/oxygen.



GBrapido said:


> see rocket motors for a good example.


But rockets carry their pre-fabricated hydrogen and oxygen in huge (and separate!) tanks, they do not produce it on the fly. NASA knows why.



GBrapido said:


> the science is sound, but be wary of the sellers of the science and what they don't know about what they sell.


Even if every single step of the science is sound, the whole concept is far from it. The problem lies in the idea of "feeding back" energy to the combustion process that has been produced by the very same combustion process.



GBrapido said:


> again this is a chemical reaction, thermodynamics only counts when the chemistry has started.


As said above, chemistry can only work within the boundaries set up by thermodynamics.



GBrapido said:


> anybody who has verifiable evidence that a product does not work, i would seriously like to see it from a professional point of view as i am totally against the scammers who sell the dream based on false claims as it does the real science and development of engines a complete dis- service.


In this we share a common opinion, however methinks that it should be those with the extraordinary claims that should deliver extraordinary, or at least verifiable, evidence to support their claims.

But OK, let us now ignore all practical difficulties like engine overheating, let us assume that the basic concept of "improving combustion" is sound, and let us look at the complete cycle. Let us further be modest and assume that by using this concept the engine's efficiency is beefed up from 30% to 40%. Which means that one quarter, so 25%, of the chemical energy going into the engine must come from the feedback loop. Now see what happens:

Fuel mixed with hydrogen/oxygen enters the engine and is burned up. 40% of the energy are maintained, the rest is wasted as heat. Now we only look at the energy that goes into the "feedback loop", which somehow must be converted into electricity in the vehicle's alternator. The alternator has an efficiency of, let's say, 90%, which is a good value. This is used to power the electrolytic process. Let us assume we have a top-range electrolytic cell with an efficiency of 50%. So 45% of the mechanical energy that enters the feedback loop finally comes out in form of a hydrogen/oxygen mix. Which means that only 18% of the original, chemical energy makes its way back through the feedback.

_We would however need 25%..._

So even if everything works as promised, and we make quite optimistic assumptions, the whole concept still *decreases overall efficiency by 8%!*

Certainly, the next thing that will be retorted on my explanation is: _"But there is spare energy available at the alternator."_

And this is the second common misconception behind such concepts. Truth is: There is no spare (mechanical or electrical) energy. If the alternator is not used to its full rating, then it will simply take in less mechanical energy. (This is neither chemistry nor thermodynamics, it is electrodynamics. :wink: ) The only "spare" energy that an engine produces is heat, and quite a lot of heat. But any concept to use that heat to increase the engine's efficiency over the Carnot efficiency would violate the laws of (yes, again :wink: ) thermodynamics.

Best Regards,
Gerhard


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## geraldandannie

I'm loving this thread  

Gerald


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## Zebedee

Me too.

A bit of rigorous scientific application for a change, instead of relying on a wave of Merlin's wand!


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## EdinburghCamper

My head hurts, any idea how much water I need to drink to take it away? If I combine with some gas and air, what will the effects be?

Gary.


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## Zebedee

EdinburghCamper said:


> My head hurts, any idea how much water I need to drink to take it away? If I combine with some gas and air, what will the effects be?
> 
> Gary.


I blush to make a suggestion, but stand downwind if you stop for a chat!! :lol: :lol:


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## 115737

EdinburghCamper said:


> My head hurts, any idea how much water I need to drink to take it away? If I combine with some gas and air, what will the effects be?
> 
> Gary.


Spontaneous Combustion!1!!"2!!"one!!eleven!2!!!!!1! :!:


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## Boff

MalphasWats said:


> It is always H2 when in gas, most of our bottled hydrogen is 'mined' and produced with acids and rocks. The world supply of Hydrogen is dwindling because once released, it doesn't stay around for long. I believe NASA has a huge stockpile carefully hoarded over the last half century or so, but you are correct, it is becoming harder to find.


In fact, about 90% of all industrially produced hydrogen is made out of methane, mainly natural gas, in a process called "Steam reforming". And hydrogen is used in large quantities for industrial purposes, mainly in the petrochemical industry and for producing fertilizers. Steam reforming is by far the most economical (and energy-efficient) process nowadays. But electrolytic production on an industrial scale is also done, and will probably become more important in the future as natural gas supplies dwindle. Downside of electrolysis is the relatively low efficiency, under laboratory conditions a maximum 57% has not been exceeded. While steam reforming reaches over 90%.

There is absolutely no need for NASA to hoard it: For one space-shuttle launch about 105 tons are needed, compared to an average world wide production of about _30 million tons per year_ this is absolutely negligible.

Best Regards,
Gerhard


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## 115737

Boff said:


> There is absolutely no need for NASA to hoard it: For one space-shuttle launch about 105 tons are needed, compared to an average world wide production of about _30 million tons per year_ this is absolutely negligible.
> 
> Best Regards,
> Gerhard


You're right, I was mistaken. It's Helium that they stockpile, not Hydrogen!

NYT Article about it, there is apparently little left!

-Mike


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## 110747

ok m gonna try and keepthis simple, but forgive me if it gets complex.

using air standard efficency with a compression ration of 12:1 the theoretical maximum amount of chemical energy that can be converted into work on the pistons is 62.9 %.

this is for a perfect engine and of course not possible to achieve.

the efficiency of the engine is governed by thermodynamic laws, principally Boyles and Charles's laws. 

But the process of combustion which is what we are interested is a chemical process.

it is absolute falicy to think that all modern engines consume all of the fuel put into the cylinder, otherwise why are we working on particulate traps, particulates or smoke is partially burnt fuel.

During combustion, the fuel reacts with the oxygen contained in the air. this oxygen is only 23.2% by weight of the charge air.

the rest is primarily Nitrogen.

the nitrogen has a detrimental effect on combustion.

The nitrogen slows down the combustion process and absorbs some of the heat liberated during the reaction of the oxygen and the fuel.

it also interferes with the contact of the oxygen molecules and the fuel agian reducing the efficiency of the chemical reaction.

If we were to run the engine on pure oxygen instead of air the temperature would be too high andand too rapid to control, i have done this and it is scary.

however by increasing the amount of oxygen present in the charge by lets say 1% we can improve the combustion, liberate more heat and speed up the conversion of energy from chemical to heat.

The fuel is principally considered to be carbon based, thus incomplete combustion of this carbon produces carbon monoxide.

all engines produce some CO which is why cats were invented and are still in use on modern engines. so this is evidence agian that all of the fuel is not used in the production of usefull heat.

To allow the theoretical complete combustion of a fuel.

using Heptane as the fuel for simplicity.

heptane is 84% carbon and 16% hydrogen.

1g of heptane requires 3.52g of oxygen

for diesel it is more like 3.25g of oxygen for each g of fuel.

so that means for each g of fuel we want to burn we need 14 g of air with normal oxygen ratio.

this is the stoichiometric ratio. 14:1

if we now add another 1 cc of oxygen which is 1.429g

we now have a charge 15.429g of which 30% is oxygen.

so what does all this chemistry tell us.

well simply by adding only 1cc of oxygen to the charge we can increase the oxygen available for the chemical process and reduce the negative impacts of the nitrogen on the chemical process.

this results in a faster burn and more of the fuel will be consumed in the chemical exothermic reaction. BUT still not 100% of the fuel will be consumed.

Now we've established we can increase the burn speed and the thermal efficiency of the engine we can move onto the thermodynamics.

as the burn starts which in a diesel is just after TDC as opposed to a petrol which is in advance of TDC.

the burn starts but the piston is moving down, this is reducing the effective compression ratio for some of the burn. this reduces the amount of energy converted from heat to work on the piston.

so by having a faster burn we improve the amount of heat converted to work as the burn takes place more whilst the pressure in the cylinder is higher.

follow so far?

also as we now have a hotter burn due to the increased amount of oxygen in our charge we also produce more heat which gives us a higher pressure, using Charles's law.

Higher MEP gives more power at the wheels.

so how does this equate to saving fuel.

well of course you don't have to put Franks slipper on the pedal so hard to get moving so you burn less fuel.

basically the addition of oxygen to the charge allows more of the fuel in the charge to burn at a higher temperature.

the release of more energy is NOT as result of the re-combining of the oxygen and the hydrogen, it is pure chemical combustion improvement.

and of course the addition of the Hydrogen is just another bit of fuel which burns easier than diesel, and helps to propogate the flame front through the nasty nitrogen.

The problem is adding oxygen makes a very unstable burn if too much is added, so the problem we are having is stabilising the burn so as not to damage the engine.

too fast a burn will end up with bad knock and the resulting damage, blow by increases as the rings cannnot re-energise quick enough, hot spots can form if the oxygen/ hydrogen is not well mixed which will burn a piston or cylinder wall. So to utilise this kind of stuff correctly the whole intake concept of the engine is under review.

i ran a racing 2 stroke engine with bottled oxygen pumped into the intake, the explosion of the crankcase was impressive to say the least and dangerous but fun anyway.

hope this goes some way to explaining why i support the technology but not the gadgeteers.

i would love to show some of you things we are working on, but i can't due to commercial confidentiallity.

Geoff


----------



## DABurleigh

"It is both. Chemistry can only work within the laws of thermodynamics."

Gerhard,

Shame on you to award Chemistry a status beyond a narrow more boring sub-set of Physics. 

The poor dears get so bored they lay claims elsewhere, too, such as "RadioChemistry". Try to get them to rationalise that with the dictionary.

Dave
Engineers' turn tomorrow


----------



## geraldandannie

Thanks for the interesting discussion on the theory of fuel burning, Geoff (not being sarcastic).

As far as this ex-mechanical engineer can understand, more oxygen in the mixture means more power (and hence, less fuel for the same work). I think this is accepted?

However, wasn't Boff's point (which is probably where we leave science behind and move into the nasty area of commerce) that the production of oxygen, in the way they are suggesting, requires more energy that the improvement they will gain.

Or have I totally missed the point (again)?  

Gerald


----------



## Zebedee

Excellent post RapidoGeoff.  

Absolutely fascinating, and reassuring as well with fossil fuel reserves decreasing rapidly. 8O :? 

Even without your specialised knowledge, many of us are quite happy to accept that the theory is sound, and wait patiently for the technology to catch up - but have little patience with the pontifications of the "Jam Jar Scientists" who are trying to sell us Snake Oil. 8O 

Don't get me wrong, there's a place for Jam Jar Science, but not here!! 8O :roll:


----------



## 115737

GBrapido said:


> ok m gonna try and keepthis simple, but forgive me if it gets complex.
> 
> using air standard efficency with a compression ration of 12:1 the theoretical maximum amount of chemical energy that can be converted into work on the pistons is 62.9 %.
> 
> this is for a perfect engine and of course not possible to achieve.
> 
> the efficiency of the engine is governed by thermodynamic laws, principally Boyles and Charles's laws.
> 
> But the process of combustion which is what we are interested is a chemical process.
> 
> it is absolute falicy to think that all modern engines consume all of the fuel put into the cylinder, otherwise why are we working on particulate traps, particulates or smoke is partially burnt fuel.
> 
> During combustion, the fuel reacts with the oxygen contained in the air. this oxygen is only 23.2% by weight of the charge air.
> 
> the rest is primarily Nitrogen.
> 
> the nitrogen has a detrimental effect on combustion.
> 
> The nitrogen slows down the combustion process and absorbs some of the heat liberated during the reaction of the oxygen and the fuel.
> 
> it also interferes with the contact of the oxygen molecules and the fuel agian reducing the efficiency of the chemical reaction.
> 
> If we were to run the engine on pure oxygen instead of air the temperature would be too high andand too rapid to control, i have done this and it is scary.
> 
> however by increasing the amount of oxygen present in the charge by lets say 1% we can improve the combustion, liberate more heat and speed up the conversion of energy from chemical to heat.
> 
> The fuel is principally considered to be carbon based, thus incomplete combustion of this carbon produces carbon monoxide.
> 
> all engines produce some CO which is why cats were invented and are still in use on modern engines. so this is evidence agian that all of the fuel is not used in the production of usefull heat.
> 
> To allow the theoretical complete combustion of a fuel.
> 
> using Heptane as the fuel for simplicity.
> 
> heptane is 84% carbon and 16% hydrogen.
> 
> 1g of heptane requires 3.52g of oxygen
> 
> for diesel it is more like 3.25g of oxygen for each g of fuel.
> 
> so that means for each g of fuel we want to burn we need 14 g of air with normal oxygen ratio.
> 
> this is the stoichiometric ratio. 14:1
> 
> if we now add another 1 cc of oxygen which is 1.429g
> 
> we now have a charge 15.429g of which 30% is oxygen.
> 
> so what does all this chemistry tell us.
> 
> well simply by adding only 1cc of oxygen to the charge we can increase the oxygen available for the chemical process and reduce the negative impacts of the nitrogen on the chemical process.
> 
> this results in a faster burn and more of the fuel will be consumed in the chemical exothermic reaction. BUT still not 100% of the fuel will be consumed.
> 
> Now we've established we can increase the burn speed and the thermal efficiency of the engine we can move onto the thermodynamics.
> 
> as the burn starts which in a diesel is just after TDC as opposed to a petrol which is in advance of TDC.
> 
> the burn starts but the piston is moving down, this is reducing the effective compression ratio for some of the burn. this reduces the amount of energy converted from heat to work on the piston.
> 
> so by having a faster burn we improve the amount of heat converted to work as the burn takes place more whilst the pressure in the cylinder is higher.
> 
> follow so far?
> 
> also as we now have a hotter burn due to the increased amount of oxygen in our charge we also produce more heat which gives us a higher pressure, using Charles's law.
> 
> Higher MEP gives more power at the wheels.
> 
> so how does this equate to saving fuel.
> 
> well of course you don't have to put Franks slipper on the pedal so hard to get moving so you burn less fuel.
> 
> basically the addition of oxygen to the charge allows more of the fuel in the charge to burn at a higher temperature.
> 
> the release of more energy is NOT as result of the re-combining of the oxygen and the hydrogen, it is pure chemical combustion improvement.
> 
> and of course the addition of the Hydrogen is just another bit of fuel which burns easier than diesel, and helps to propogate the flame front through the nasty nitrogen.
> 
> The problem is adding oxygen makes a very unstable burn if too much is added, so the problem we are having is stabilising the burn so as not to damage the engine.
> 
> too fast a burn will end up with bad knock and the resulting damage, blow by increases as the rings cannnot re-energise quick enough, hot spots can form if the oxygen/ hydrogen is not well mixed which will burn a piston or cylinder wall. So to utilise this kind of stuff correctly the whole intake concept of the engine is under review.
> 
> i ran a racing 2 stroke engine with bottled oxygen pumped into the intake, the explosion of the crankcase was impressive to say the least and dangerous but fun anyway.
> 
> hope this goes some way to explaining why i support the technology but not the gadgeteers.
> 
> i would love to show some of you things we are working on, but i can't due to commercial confidentiallity.
> 
> Geoff


All this is fine, I don't think anyone is disputing the fact that if you put more combustible substance into the system, you get more power, therefore re-tuning the fuel system to inject less fuel gives the same power for slightly less 'petrol' because you've got a bit extra 'fuel' from any hydrogen, plus a bit better combustion from a bit extra oxygen.

Fine.

HOWEVER 

if that extra fuel was produced as a result of using some of the power from the engine (i.e. 'hydrolysised') then the law of conservation of energy prohibits it from generating any more power than it took to do it in the first place.

Strap a Hydrogen and Oxygen tank to an engine, you'll get more go. Make that Hydrogen and Oxygen from water using energy from the engine, no effect (use a separate power source, perhaps, you could strap a generator to the bonnet to generate the electricity to do the electrolysis 8O). It is quite simple Physics (for which I proudly own an A-Level  ) : Energy Out cannot ever be more than (and is unlikely to be equal to) Energy In.


----------



## 110747

> But OK, let us now ignore all practical difficulties like engine overheating, let us assume that the basic concept of "improving combustion" is sound, and let us look at the complete cycle. Let us further be modest and assume that by using this concept the engine's efficiency is beefed up from 30% to 40%. Which means that one quarter, so 25%, of the chemical energy going into the engine must come from the feedback loop. Now see what happens:


this is the fundamental misconception.

the extra chemical energy does NOT come from the oxygen or hydrogen that you produce from the alternator.

this oxygen and hydrogen is used to help release more of the chemical energy in the diesel that is curently not released.

Geoff


----------



## Zebedee

Hmmmmm.

Not sure about that Malphas??

Your Physics theories are obviously quite correct, and I don't know if this is so or not, but what if . . . .

. . . the added oxygen can enable the release from the fuel (diesel?) of more energy than was required to produce the oxygen itself.

Dunno. Will have to wait for Gerhard or Geoff to do the sums.  

_(Edit . . . Just posted and saw Geoff's reply. (Smug or what!!   :roll: :roll: )_


----------



## 115737

Zebedee said:


> Hmmmmm.
> 
> Not sure about that Malphas??
> 
> Your Physics theories are obviously quite correct, and I don't know if this is so or not, but what if . . . .
> 
> . . . the added oxygen is able to enable the release from the fuel (diesel?) of more latent energy than was required to produce the oxygen itself.
> 
> Dunno. Will have to wait for Gerhard or Geoff to do the sums.


Surely it would be much simpler to invent some kind of forced-air system that increases the amount of air in the fuel mixture, we could call it a turbo! :wink:.

Besides, oxygen will react just as well with the hydrogen, and since hydrogen is so volatile, there is a much higher chance that all of the hydrogen will be consumed to create exactly the same amount of water as when you started, using up all of the extra oxygen and taking the same (if not slightly more) energy it took to break it all apart in the first place! And the Universe spins on, content that its energy is safe and accounted for.


----------



## 110747

> Surely it would be much simpler to invent some kind of forced-air system that increases the amount of air in the fuel mixture, we could call it a turbo! .


i think i'm beginning to hear the sound of small denomination coins hitting the ground.

just done some basic and quick and dirty sums here.

assuming 2500 cc engine.

each cylinder uses 625cc of air assuming 100% volumetric efficiency.

this gives .53g of fuel per combustion.

fuel calorific value = 0.046 mJ /kg

100% combustion would give us 0.02438 MJ of energy released

= 248606.812 Kg f *cm

= 24.2 KW sec

at 2000 rpm maximum burn time is 0.0625 secs if it is to do any work.

= 524 HP.

for 1 firing alone at 2000rpm

so please be assured that not all of the energy is converted from the fuel to work.

Geoff


----------



## johng1974

> for 1 firing alone at 2000rpm


One cylinder?


----------



## 110747

> Surely it would be much simpler to invent some kind of forced-air system that increases the amount of air in the fuel mixture,


the problem is you don't actually want air in the cylinder, you want oxygen.

Nitrogen is inert and just hinders the combustion and makes NOX as a by product.

but the Nitrogen is used to stabilise the burn a bit so its not all bad.

modern diesels are already running lean with excess air to reduce the smoke to below emmission limits.

so this will seem contradictory to everything i said but there is already enough air in the cylinder, the problem is actually the fuel and getting it to burn well.

the analogy i use is that a stick of wood 5mm diameter 100mm long has enough caliries to boil a cup of water, but if you just light it in air and hold it under the cup i bet you can't boil the water.

but create the right conditions, such as powderise it and blowit mixed with oxygen at a vacuum sealed cup and you will do it easily.

Geoff


----------



## Boff

Hi again!



GBrapido said:


> ok m gonna try and keepthis simple, but forgive me if it gets complex.
> 
> using air standard efficency with a compression ration of 12:1 the theoretical maximum amount of chemical energy that can be converted into work on the pistons is 62.9 %.
> 
> this is for a perfect engine and of course not possible to achieve.
> 
> the efficiency of the engine is governed by thermodynamic laws, principally Boyles and Charles's laws.
> 
> But the process of combustion which is what we are interested is a chemical process.
> 
> it is absolute falicy to think that all modern engines consume all of the fuel put into the cylinder, otherwise why are we working on particulate traps, particulates or smoke is partially burnt fuel.
> 
> During combustion, the fuel reacts with the oxygen contained in the air. this oxygen is only 23.2% by weight of the charge air.
> 
> the rest is primarily Nitrogen.
> 
> the nitrogen has a detrimental effect on combustion.
> 
> The nitrogen slows down the combustion process and absorbs some of the heat liberated during the reaction of the oxygen and the fuel.
> 
> it also interferes with the contact of the oxygen molecules and the fuel agian reducing the efficiency of the chemical reaction.
> 
> If we were to run the engine on pure oxygen instead of air the temperature would be too high andand too rapid to control, i have done this and it is scary.
> 
> however by increasing the amount of oxygen present in the charge by lets say 1% we can improve the combustion, liberate more heat and speed up the conversion of energy from chemical to heat.
> 
> The fuel is principally considered to be carbon based, thus incomplete combustion of this carbon produces carbon monoxide.
> 
> all engines produce some CO which is why cats were invented and are still in use on modern engines. so this is evidence agian that all of the fuel is not used in the production of usefull heat.
> 
> To allow the theoretical complete combustion of a fuel.
> 
> using Heptane as the fuel for simplicity.
> 
> heptane is 84% carbon and 16% hydrogen.
> 
> 1g of heptane requires 3.52g of oxygen
> 
> for diesel it is more like 3.25g of oxygen for each g of fuel.
> 
> so that means for each g of fuel we want to burn we need 14 g of air with normal oxygen ratio.
> 
> this is the stoichiometric ratio. 14:1
> 
> if we now add another 1 cc of oxygen which is 1.429g
> 
> we now have a charge 15.429g of which 30% is oxygen.
> 
> so what does all this chemistry tell us.
> 
> well simply by adding only 1cc of oxygen to the charge we can increase the oxygen available for the chemical process and reduce the negative impacts of the nitrogen on the chemical process.
> 
> this results in a faster burn and more of the fuel will be consumed in the chemical exothermic reaction. BUT still not 100% of the fuel will be consumed.


I have no doubt that so far this is correct.

But: To get this 1g of oxygen out of electrolysis you have to convert 1.13g of water. Breaking up this amount of water requires 36 kJ (kilojoule) of (chemical) energy. With an assumed efficiency of your electrolysis of 50% this means that you have to invest 72kJ of electrical energy. So the alternator (efficiency 90%) draws 80kJ mechanical energy. To produce this 80kJ the engine (efficiency assumed to be 40%, so we already consider an efficiency increase) needs to burn 200kJ worth of fuel. Taking Heptane this would mean 4.5g. To burn these 4.5g of fuel you need 15.84g of oxygen. 8O

*So, to win 1 additional gram of oxygen, you have to invest almost 16 grams of oxygen in the first place!*

So even if this modification increases the engine's efficiency, the losses occuring within the process eat up all possible gains. Even if you had a 100% efficiency in your electrolysis, the ratio would still be 1:8.

The only reason why engines fitted with such a thing do not suffer from a significant loss of efficiency is that the amounts of hydrogen/oxygen created in practical use are far too low to be accounted for.



GBrapido said:


> i ran a racing 2 stroke engine with bottled oxygen pumped into the intake, the explosion of the crankcase was impressive to say the least and dangerous but fun anyway.


I do believe that. But it has nothing to do with what we are talking about here. Because with bottled oxygen the production process is not taken into account.



GBrapido said:


> this oxygen and hydrogen is used to help release more of the chemical energy in the diesel that is curently not released.


Even if that is true, you still need energy to produce the hydrogen/oxygen mix. Which will more than eat up all possible gains in efficiency.

Fact is that modern engines, no matter whether diesel or petrol, burn up more than 99% of the fuel inside the cylinders. Otherwise they would fail all emission regulations even with the best exhaust filtering system. So, by increasing burn rate, not more than 1% can be possibly gained.

Removing nitrogen and replacing it by oxygen is more effective, that is true, however it only works out if the oxygen is taken from bottles.

Best Regards,
Gerhard


----------



## 110747

98 to 99% of the fuel may well be burned or partially burned in the engine.

this is not the issue.

the issue is how much of the chemical reaction of burning can be converted into usefull energy.

most of the heat generated is wasted and not used to create expansion and thus power.

the charge will still be burning when the exhaust valve opens.

by speeding up the burn in a high speed diesel engine more of the heat can be converted to power.

the faster the burn the more heat is generated when the compression is highest, before the piston gets too far down the bore.

the higher the compression ratio the more power will be produced and the more thermally efficient the burn will be.

Geoff


----------



## Boff

Hi again,

last attempt...



GBrapido said:


> 98 to 99% of the fuel may well be burned or partially burned in the engine.
> 
> this is not the issue.


This is really not the issue.

The issue is that any _feedback_ of mechanical energy from the engine's crankshaft back to the intake, to increase efficiency, burn rate, whatever, is the same principle as Baron Münchhausen pulling himself out of the swamp by his own bootstraps...

To gain one gram of oxygen via the feedback loop requires 18 grams to be put in first. And these 18g of oxygen, together with the fuel they burned, are lost, gone, and cannot be used for traction.

If you go to a slot machine, throw in 18 quid, and one quid comes out at the end, would you call that a win? I would call it a loss.

Best Regards,
Gerhard


----------



## 110747

> To produce this 80kJ the engine (efficiency assumed to be 40%, so we already consider an efficiency increase) needs to burn 200kJ worth of fuel


using these numbers, we know 1% increase in oxygen gives an improvement in fuel consumption.

the numbers of 1g gave us 7% increase in oxygen.

so to keep it simple assume 1/7th of a gram for 1% oxygen increase.

so only 28 kJ of extra energy is now needed.

still too much to expect.

so lets half it again to 0.5% increase in Oxygen.

now we only need 14 kJ of extra energy.

as we are shoving 25 kJ into the engine we would need a huge increase in efficency to achive the extra 14 kJ.

so half it again.

now just 7Kj for .25% increase in oxygen.

with potentially out of the 25 kJ added to the engine the numbers are still unrealistic.

i'm sure the numbers you quote are right, here are my numbers.

237.13 kJ of energy is required to produce 1 mole hydrogen and half a mole of oxygen.

1 mole = 22.4 litres of oxygen.

1/2 mole of oxygen gives 11.2 litres of oxygen.

for 1 charge by volume we assume 625 cc volume.

100 % volumetric eff = 135.3 cc of oxygen in the cylinder.

to get 1% increase in oxygen we need 193.6 cc of oxygen.

meaning we need to add 58.4 cc of oxygen.

= 0.0026 moles of oxygen per charge to be added.

= 0.618 kJ of energy required per charge from the available fuel of 25 kJ

so a thermal efficiency increase of only 2% is needed from the already available fuel calories will give us the 1% extra oxygen needed.

sums a bit rushed so please accept my apologies if wrong.

Geoff


----------



## Mikemoss

I'm glad I dropped out of physics and chemistry at school.

But I'm also glad that some of you obviously didn't. I shall await the outcome of this thread with keen interest!


----------



## duxdeluxe

Great stuff - like many others the technology left me a bit behind the curve some time ago but I never thought that science could be made so interesting to ordinary people like the undersigned.

One point for clarification though - quote _this oxygen is only 23.2% by weight of the charge air_ i though that was 20.9% or was that by volume?

I know understand much more than i did before and am sure that applies to many. We still have consensus that the technology might exist but too many snake oil salesmen are trying to capitalise on it.


----------



## 110747

complety agree. we have shown that it is so complex for the man in the street to understand easily that the snake oil salesmen use it to there advantage.

the same thing is happening in the solar panel sales arena.

please don't spend money on these scam merchants untill they prove it works.

someone please get a free sample and test it out.

Geoff


----------



## SpeedyDux

I think I understand what Geoff is getting at here: improving the combustion efficiency of the fuel in a particular engine rather than trying to get "free" energy that defies conservation laws. 

I seem to recall that the best marine diesel engines can achieve about 50% efficiency. Feel free to correct me if I am wrong. The diesel engines fitted by FIAT, Ford, Mercedes etc. still have a lot of catching up to do. Any retro fit kit that in practice can close the efficiency gap and has a reasonable payback time is fine with me. I don't need to understand the science. I leave that to the boffins and engineers.

Come on, let's see a proper independent test!


SD


----------



## oldenstar

Absolutely fascinating stuff, and hats off to some of the brains who find the time to post on here.

Science is great but it's a good job nobody told Bumble Bees that they couldn't fly! :wink: 

(And before I get hammered that is tongue in cheek-I have read about it)

Paul


----------



## geraldandannie

I think the crux of the matter is (for my simple brain):

Given that the efficiency of the engine can be improved with the addition of oxygen into the combustion process, the process by which this particular system produces oxygen (i.e. electrolysis) takes more energy than the extra efficiency of the engine will produce. I think.

Mind you, the conservation of energy doesn't apply, because the energy to produce the fuel in the first place (getting it out of the ground and cracking it into diesel / petrol) is discounted. So, any improvement in the burn efficiency of the process _could_ release more of the potential energy in the fuel.

One day, I'll understand it.

Gerald


----------



## 110747

goen mins spare so just take the numbers a bit further which will show why i am against the snake oil products.

again these are rough numbers and not specific to an engine.

using my gas flow figures for 1% increase in oxygen

at 2000 rpm we have 240,000 bangs per hour.

at 58cc per bang added we will need 14,000 litres of oxygen per hour.

=625 moles of oxygen per hour.

at 237 kj per mole (22.4 litres from Avagadro's gas constant )

using the 50% efficiency of the electrolyser we need 474 kJ per mole

=296.25 mJ of energy needed from the alternator.

this equates to 41.215 kW hours

a lot.

so you see with these kind of numbers although it works and the energy is available in the fuel that is wasted as heat it is simply not viable in this form or at these percentages.

the wires will be too thick. :lol: 

so the gadgets you see are using very small amounts of oxygen / hydrogen or are storing it up when times are easier to use when times are hard.

look at the current draw from the device and it is easy to calculate the amount of oxygen and hydrogen being generated.

it really is small amounts and i have only seen one system which i have tested and driven that i know works, and it has some pretty clever electronics modifying the map as it goes and as Oxygen and hydrogen are available in the volumes it needs. this system does reduce overall consumption and works, but is not available to buy.

and the snake oil sellers will kill the technology anyway.

Geoff


----------



## Boff

GBrapido said:


> this equates to 41.215 kW hours
> 
> a lot.


Yes, quite a lot. But not the wires are the problem: :wink:

The kWh need to be generated. By the engine. _In addition_ to the energy that is needed to propel the vehicle during this hour.

For instance, my MH, driven at 100 kph for one hour, needs about 12.5 litres of diesel. Diesel fuel has a heating value of 9.8 kWh per litre, so that is the absolute maximum amount of energy that you can possibly get out of it. So my diesel takes in fuel worth of 122.5 kWh during this one hour of driving. It is realistic to assume a 30% efficiency of the engine and a 25% efficiency of the whole propulsion system, so out of the 122.5 kWh only 30.625 finally arrive at the wheels. So, to drive my MH over a distance of 100 km within one hour, I need 30.625 kWh with an unmodified engine. The 12.5 litres of diesel fuel weigh approx. 10 kg, and to burn up 10 kg of diesel I need about 36.5 kg of oxygen.

Now I want to modify my combustion by adding 1% of "home-made" oxygen. 1% of 36.5 kg is 365 grams. To produce this via electrolysis - see my previous posts - I would need 26,280 kJ of electrical energy from the alternator. Which is 7.3 kWh. So the engine would have to produce an additional 9.125 kWh of mechanical energy during this hour, just to produce the oxygen. Thus, to break even, the total efficiency of the whole propulsion system would have to rise from 25% to 32%, and the engine's efficiency from 30% to 38%.

This is, however, only to break even, means this efficiency increase only compensates the losses from the electrolysis. So if mileage is to be increased, then the engine's efficiency must be raised up to even more than 38%! If I want to use this principle to increase my mileage by 10%, then the engine's efficiency would have to be at 42%.

Geoff, please, don't tell me that adding merely 1% of oxygen to the air intake will raise the engine's efficiency from 30% to 38% (breakeven), let alone 42% (10% mileage improvement). That would really be snake oil.

Best Regards,
Gerhard


----------



## 110747

using your numbers we add 365g of oxygen.

we also add 730g of hydrogen.

cal value of hydrogen being 119.93 kJ/g

giving an addition of 87,089 kJ of energy.

at lets say 60% combustion efficency, which is bad for hydrogen.

we now have 52,253.4 kJ

50 % efficency for the electrolysis gives

26,126.7 kJ

90% for the alternator gives

23,514.03 kJ

so we only need an extra 2766 kJ liberating from the diesel we are already burning badly.

this is 0.768 kW hours

so the required increase in combustion thermal efficiency is actually about 2.5 %

also the addition of hydrogen, displaces the same volume of air, this brings the air fuel ratio nearer to stoich than a modern diesel which runs very lean to avoid visible smoke.

Geoff


----------



## eddied

*Snake Oil*

 Wow, all good fascinating stuff this.
So, at the end of the day, how much per litre is snake oil, and where do I buy it?
saluti,
eddied


----------



## Zebedee

*Re: Snake Oil*



eddied said:


> Wow, all good fascinating stuff this.
> So, at the end of the day, how much per litre is snake oil, and where do I buy it?
> saluti,
> eddied


Loadsamoney . . . and avaiably _*only *_from Zeb Industries Inc.

:lol: :lol: :lol:


----------



## 110747

d't buy it.

make your own.

take one snake.

squash it into a couple of jam jars.

add a bit of elbow grease

go to the shop for a long weight

the snake will break down into snake oil, or some other nasty fluid

filter out the boney bits.

bottle and add to the fuel with a shot of redex.

Geoff :lol: :lol:


----------



## Boff

Hi!



GBrapido said:


> we also add 730g of hydrogen.


No. Maybe this is the reason for all misunderstanding?

Oxygen has a molar mass of 15.9994 g/mol, hydrogen has 1.00794 g/mol. As for each atom of oxygen we get two atoms of hydrogen, if we produce 365 g oxygen by breaking up water, we only get 46g of hydrogen, not 730g.



GBrapido said:


> giving an addition of 87,089 kJ of energy.


No.

As we have only 46g hydrogen available, we only get: 5,517 kJ.



GBrapido said:


> at lets say 60% combustion efficency, which is bad for hydrogen.


No.

We use 10 *kilo*grams of Diesel, and we add 46 grams of hydrogen. The influence on the engine's efficiency will therefore be negligible. And of cause the mechanical (friction etc.) losses after the engine are not changing at all, so with the above corrections we only have: 1,379kJ.



GBrapido said:


> 50 % efficency for the electrolysis gives...


689.6kJ



GBrapido said:


> 90% for the alternator gives


80% for the alternator is more realistic, but even if it is 90% we then have not more than

620.7kJ, or 0.1724 kWh

So, if we consider not only the oxygen, but also the hydrogen, and assume that ALL the hydrogen takes part in the combustion process (which is rather improbable as hydrogen is very likely to leak out somewhere), the _diesel fuel_ still has to provide an extra 8.9526kWh.



GBrapido said:


> so the required increase in combustion thermal efficiency is actually about 2.5 %


No.

Given all the above mentioned corrections, the effect of the hydrogen remains in the sub-percentage area and we still need to increase the engine's thermal efficiency from 30% to 38% for breakeven.

Best Regards,
Gerhard


----------



## johng1974

Fascinating..



do snakes have bones ?


----------



## Zebedee

This gets better and better. 

What a great thread - really fascinating, and good to see reason prevailing over guestimates and loosely based opinion. 

*And *it all remains amicable and respectful of others' opinions - unlike a previous thread which has been mentioned! :roll:

_(Either of you know the meaning of life by any chance?)_ :lol: :lol: :roll:


----------



## Boff

Zebedee said:


> _(Either of you know the meaning of life by any chance?)_ :lol: :lol: :roll:


In my opinion life does not _have_ a meaning. Life _is_ the meaning. :wink:

Best Regards,
Gerhard


----------



## 110747

sorry you are of course correct, i was thinking volumes and wrote grams.

when i wrote it i tthought the numbers looked all wrong, but was in a bit of a rush so didn't think about what i wrote.

i was trying to get to the volumetric bit that the volume of hydrogen will be double the oxygen, thus displacing more air with fuel with the result of a richer burn nearer to stoich. which of course means more power.

the system i have seen that i know works, injects the hydrogen directly into the cylinder at high pressure.

the thermal efficiency is improved by the addition of even a small amount of hydrogen and oxygen as it promotes a faster and more complete burn during the phase of the piston when it can do work.

i cannot prove with numbers however the increase in thermal efficency as a result of this improvement. and you're right its not 20%

but the 8% is achievable for break even and with the other changes of the richer running etc more power is produced by the engine. and producing whilst on the over-run etc.

the question is how much oxygen is actually needed as the 1% is a figure i know works but we also know that the low voltage systems cannot produce 1% fumigation but they claim to work as well.

so i stand by my position but unable to prove with numbers the technology i have seen and tested that i know works


----------



## 110747

> (Either of you know the meaning of life by any chance?)


42


----------



## 110747

> do snakes have bones ?


i believe they have a skull.

sorry pHd in engineering not biology

:lol: :lol:

Geoff


----------



## johng1974

wish i had one of them :lol:


----------



## 91344

Hi,
I used to be an industrial engineer with BL, we knew all about water injection since Benz invented the engine, not practical, and things go rusty with all that water around.

To work you need equal quantities of fuel and water.

I'm not a scientist, but I don't think that you can release the hydrogen from H2O with the power from a 12 volt battery. AGD


----------



## Boff

GBrapido said:


> i was trying to get to the volumetric bit that the volume of hydrogen will be double the oxygen...


You are right about the volumes. However, keep in mind that you feed in a stoichiometric mixture of hydrogen and oxygen. So what will happen:

Hydrogen and the additional oxygen are in perfect stoichiometric balance, they will (again we neglect all possible leakage) completely recombine with each other. Well, not necessarily the same molecules, but by ratio it works out. And in the process add 1.5kWh (the 5,517 kJ) of thermal energy to the energy from the diesel, which is about 1.1%.

The diesel, however, will have 3% less air available for combustion, and therefore also 3% less oxygen! So, instead of increasing the diesel's burn rate, we are actually decreasing it. 8O



GBrapido said:


> ...thus displacing more air with fuel with the result of a richer burn nearer to stoich. which of course means more power.


Yes, if you reduce air (and with it oxygen) you will be closer to stoichiometric equilibrium. But no, this will not mean more power! In a diesel engine it will even mean less power.

Remember, that when petrol engines were equipped with catalytic converters and oxygen sensors, their efficiency suffered from it. This is because these engines have to run almost exactly at the stoichiometric fuel/air ratio.



GBrapido said:


> the system i have seen that i know works, injects the hydrogen directly into the cylinder at high pressure.


Completely different story. Has nothing to do with what we are talking about here.



GBrapido said:


> so i stand by my position but unable to prove with numbers the technology i have seen and tested that i know works


Well, all the science that I can come up with (and as you might have realized, I am a physicist :wink: ) stands against that. So there is only one way for you to convince me (and probably many other readers here): Have an independent organization put an unmodified car on a dynamometer, and run any standardised test cycle. Then apply your modifications and have them run the same test cycle again. And publish the results.

Best Regards,
Gerhard


----------



## 110747

> wish i had one of them


what a skull?

:lol: :lol:


----------



## Jiggles

A lot of WWII fighter aircraft had water injected engines for extra power.
John


----------



## Zebedee

Jiggles said:


> A lot of WWII fighter aircraft had water injected engines for extra power.
> John


Different principle altogether John. 

There's a good explanation somewhere in this or previous threads . . . if you can find it. :roll: :roll:


----------



## 110747

> [The diesel, however, will have 3% less air available for combustion, and therefore also 3% less oxygen! So, instead of increasing the diesel's burn rate, we are actually decreasing it.


no.

the mixture is already lean in a diesel with the ratio at about 19:1

there is more air in the mix than is needed so reducing the amount of air will not reduce the power from the fuel.

what it does is replace the inert nitrogen with hydrogen fuel and oxygen oxidiser so the combustion charge is more volatile.



> Yes, if you reduce air (and with it oxygen) you will be closer to stoichiometric equilibrium. But no, this will not mean more power! In a diesel engine it will even mean less power.


disagree. for a given volume of charge the more fuel we put in the more power is produced as long as combustion is complete and sufficient oxygen is available which it will be if we're at stoich.

how do engine tuners obtain 20% more power from a diesel engine by modifying the map? if its already perfect.

because there is already plenty of oxygen available so you can add more fuel. (ignoring emmisions).



> Well, all the science that I can come up with (and as you might have realized, I am a physicist ) stands against that. So there is only one way for you to convince me (and probably many other readers here): Have an independent organization put an unmodified car on a dynamometer, and run any standardised test cycle. Then apply your modifications and have them run the same test cycle again. And publish the results.


i had realised you were a physicist, and am enjoying the exchange with a proffessional, i'm just a humble engine designer.



> Then apply your modifications and have them run the same test cycle again. And publish the results.


these are NOT my modifications. the test car i have driven and looked at the dyno results from was built by a very large OEM based in the US.

they are their modifications, not mine.

they won't publish confidential data, and neither will i.

i'm just trying to get to the bottom of what i have seen.



> Well, all the science that I can come up with (and as you might have realized, I am a physicist ) stands against that


well from your numbers you show that we need 8% increase in power of the engine to break even.

not beyond possibility and i have an alternator sat here from a ford focus that is 96% efficent and 100% efficient as a paper weight.

some manufacturers of electrolisers are claiming 85% efficiency of there units ( not Proven ) (ITM Power being one)

in the same way i can't prove the effects on combustion through fumigation you cannot disprove them either.

it is for the makers of these units to prove their claims, and this thread started from an independant magazine publishing these claims, not me.



> Motor Caravan magazine has done a review this month on a hydrogen kit, supplied by Towtal, which has improved the mpg of a new 2.5 Transit by 38 per cent, no less.


Geoff


----------



## eddievanbitz

My father used to put dehydrated water tablets in our tractors years ago. I still use the same brand now in my motorhome, although other family members have switched to French ones made by Volvic which they claim are better.

A contributor on this site heads up a research team that has so far eaten through millions in investment is nearly to market with a device that will recover about 18% of fuel and will cost a damn site more than the costs discussed here, so the whole research team will be gutted that they didn't buy one of these instead 8O


----------



## oldenstar

Ooh-er!
I heard the words 'Free Energy' in there.

Helmets ON.


----------



## 110747

not really because taking someone else's invention is not a good business model.

having your own IP and selling that is a good business model.

lots of companies are looking at lots of ways to reduce fuel consumption with a view to making large amounts of money, not saving the planet.

and we could all drive round in a little bubble car and get 75MPG + but no we insist on driving heavy MH's with poor aero and hopefully get 30mpg.

Geoff


----------



## johng1974

> what a skull?


I just knew you'd do that


----------



## eddievanbitz

> not really because taking someone else's invention is not a good business model.


Hi Geoff, Did you mean my statement


> so the whole research team will be gutted that they didn't buy one of these instead


It was me being flippant, suggesting that if it were simple to get fuel savings of 40% that no one knows about it.

I didn't really mean that for an outlay of £600 odd quid they could have saved millions in research

Cheers

Eddie


----------



## Boff

Hi,

this will now definitely be my last post on this thread. It was fun discussing with you so far, but now I feel that things start turning in circles.



GBrapido said:


> what it does is replace the inert nitrogen with hydrogen fuel and oxygen oxidiser so the combustion charge is more volatile.


No.

It replaces _air_, not only nitrogen. Means if you introduce 3% volume of hydrogen/oxygen mix, you reduce _air volume_ by 3%.

(Edit: The following paragraph has been corrected)
_So the relative volumes of both nitrogen, and oxygen from air, are reduced by 3%. As the relative volume of oxygen in air is 21%, this means that introducing a total volume of 3% of a stoichiometric mixture of hydrogen and oxygen into the air flow, the total oxygen level in this air flow will only be increased by a meagre .37%. And the oxygen level available to burn diesel will even be reduced by .63%._

And, no matter what you do, just a warning: Make sure that the hydrogen level always stays below 4%. Because if it exceeds this value, it will not simply combust anymore, it will *detonate!* Which means that you don't have a simple and smooth pressure increase anymore, but a supersonic blast wave inside the cylinder. This will destroy your engine in very short time.



GBrapido said:


> how do engine tuners obtain 20% more power from a diesel engine by modifying the map? if its already perfect.


The original engine map is never perfect. It is always a compromise between power, fuel efficiency and emissions. If engine tuners beef up the power, they not only ignore emissions, but also efficiency.



GBrapido said:


> they are their modifications, not mine.
> 
> they won't publish confidential data, and neither will i.


So if their data is that spectacular, why keep it confidential?



GBrapido said:


> well from your numbers you show that we need 8% increase in power of the engine to break even.
> 
> not beyond possibility and i have an alternator sat here from a ford focus that is 96% efficent and 100% efficient as a paper weight.
> 
> some manufacturers of electrolisers are claiming 85% efficiency of there units ( not Proven ) (ITM Power being one)


All that will only reduce the losses of the electrolysis cycle, it has yet to be proven that this "fumigation" can increase efficiency.



GBrapido said:


> it is for the makers of these units to prove their claims...


Here I totally agree. However I would expect that this proof is done under control of an independent organization, under the eyes of the open public, and published in a proper scientific magazine, after having passed the scrutiny of their review panel. And that the most important of all criteria for a proper scientific experiment is fulfilled: The setup must be published in such detail, that the experiment can be reproduced, and always leads to the same result.

OK, now here is my conclusion:

Different sources claim that it is possible to increase efficiency of an existing engine by introducing a small amount of a hydrogen/oxygen mix into the air intake, which is produced by an electrolyser powered by the engine's own alternator. Some of these sources even claim that you can botch up this thing using only household materials, and that it still has an effect. The others sell their solution for a considerable amount of money.

Now, compared to most other members of this forum I have a slight advantage, and this is my scientific education. So, before parting with any money (or cups from my cupboard :wink: ), I can use scientific principles and methods, and a pocket calculator, to get to the bottom of these claims.

I have done that, and I have written the results, and the logic that lead to these results, here in this thread. And the result is: There simply is no bottom! Whatever I try, and I have given more than enough benefit of the doubt, it will end up either in a reduction of engine efficiency, or in violation of basic physical principles like the laws of thermodynamics.

So, unless a proper scientific experiment carried out under the above mentioned conditions, prooving me wrong, I will consider this as pseudo-science, as "snake oil". And I can only recommend to anyone else to do the same.

Best Regards,
Gerhard


----------



## Zebedee

Thanks Gerhard, GB and others.

Me brain hurts, but I really enjoyed following this thread.    

I'm a "failed" physicist. I can understand the concepts easily enough, but I just can't handle the higher maths.

Best thread of its type for a long time - and no aggro or animosity!


----------



## Boff

Hi again,

well, normally I do write postings after a last posting. :wink: But this time I have to because I have made a tiny mistake. Nothing serious, the principle is still sound, but some figures in my last posting are slightly off. 

I have therefore edited my previous posting. And learned from it that I should not do science after a beer...  

Best Regards,
Gerhard


----------



## 110747

hi gerhard, i realise that was your last post and you will remain un-convinced, and i'm at the limit of my chemistry / physics with the combustion process

however i enclose some abstracts for you to look at.

and please remember i'm not trying to defend the HHO system scammers, just the technology of oxygen / hydrogen enrichment.

regards

Geoff

SAE paper.

A New Look At Oxygen Enrichment--The Diesel Engine
Document Number: 900344

Date Published: February 1990

Author(s): 
Harry C. Watson - University of Melbourne 
Eric E. Milkins - University of Melbourne 
Geoff R. Rigby - BHP Central Research Labs., Shortland, N.S.W.

Abstract: 
New concepts in oxygen enrichment of the inlet air have been examined in tests on two direct injection diesel engines, showing: significant reduction in particulate emissions (nearly 80% at full load),* increased thermal efficiency if injection timing control is employed*, substantial reductions in exhaust smoke under most conditions, ability to burn inferior quality fuels which is economically very attractive and achivement of turbocharged levels of output with consequential benefits of increased power/mass and improved thermal efficiency. The replacement of an engine's turbocharger and intercooling system with a smaller turbocharger and polymeric membrane elements to supply the oxygen enriched stream should allow improved transient response. NO\dx emission remain a problem and can only be reduced to normally aspirated engine levels at some efficiency penalty.

Use of Oxygen Enriched Air in a Direct Injection Diesel Engine
R Udayakumar, Non-member
A K Meher, Non-member
The internal combustion (IC) engine has a predominant role in stationary low power generation and a virtual monopoly
in mobile applications today. One of the methods to reduce the emissions in a diesel engine is by oxygen introduction into
the combustion chamber which can be done by supplying the oxygen into the inlet manifold during suction stroke. The
experimental part of this work involves the fabrication of a separate system consisting of a mixing chamber. Oxygen is
introduced in the inlet manifold through this chamber and different tests like heat balance test, performance test and
emission measurements are conducted on a Kirloskar engine (a single cylinder direct injection diesel engine) to get the
effect of oxygen on the different parameters like brake thermal efficiency, fuel consumption, NOx and smoke at different
load conditions. Load test was conducted for various flow rates of oxygen (2 cc/s to 2.7 cc/s). It is found that oxygen
enrichment results in better combustion which resulting in decrease in fuel consumption and increase in brake thermal
efficiency. From the heat balance test it is found that oxygen enrichment increases the heat in the exhaust, consequently
increasing the heat in the cooling water. The optimum oxygen flow rate was found to be 2.5 cc/s which is about 18% of full
load air consumption of the base engine.

there are many many more papers published that report tests done with the same results.


----------



## 110747

another paper

The experimental results demonstrate that the hydrogen addition in the intake air has an
influence on improvement of engine power, and energy consumption (Fig. 5, 7, 8). NO
emissions are very complicated (Fig. 9). Higher smoke of exhaust gases is observed (Fig. 10).
The higher engine power with hydrogen addition (Fig. 5, 7) is due to the additional heat
released from hydrogen combustion and to the reduced combustion duration (1). The
combustion of hydrogen addition provides additional heat energy, which is one of the reasons
for Ð° higher engine output. The shorter combustion duration causes lower heat transfer rate
thought the combustion chamber walls and higher diesel fuel heat utilization. As a result of
the calculations that were done, the increase of the whole heat added to the engine cycle due
to hydrogen combustion is 2,44% averaged over the entire investigated engine speed region.
But the averaged power improvement obtained as a result of the experimental investigation is
15% (Fig. 7). The middle indicated pressure improvement at 1500 rpm is 14.8% (Fig. 5).
These facts show that the power improvement comes not only from the energy added as a
Mihaylov, Barzev 6 11/02/2004
result of hydrogen addition. The greater part of power increase is due to combustion process
improvement by the means of combustion duration reduction because of superior combustion
and flame propagation properties of hydrogen. The proofs of this statement are the curves of
net heat release and net heat release rate shown respectively on (Fig. 4) and (Fig. 3).
0.7
0.75
0.8
0.85
0.9
1200 1300 1400 1500 1600 1700 1800 1900
n, rpm
hv
diesel fuel
H2 addition"
1
1.2
1.4
1.6
1.8
2
2.2
1200 1300 1400 1500 1600 1700 1800 1900
n, rpm
a
diesel fuel
H2 addition
Fig. 11 Volumetric efficiency Fig. 12 Air-fuel ratio
The combustion duration reduction is due to reduced mixing-controlled combustion phase
invoking higher net heat release rate (Fig. 3) and higher net heat release respectively (Fig. 4).
The reduction of mixing-controlled combustion phase is due to the flame propagation of
homogeneous hydrogen-air mixture trough the combustion chamber. The flame propagation
improves the diffusion process (incurring many molecular collisions) between the hot air and
diesel fuel vapors causing it’s faster completing. The diffusion process improvement causes
higher heat utilization and higher net heat release respectively.
It makes impression that the net heat release curve of hydrogen addition has higher values
(immediately after injection) in comparison with that of diesel fuel (Fig. 4). The decrease of
net heat release curve is due to heat consumption necessary for diesel fuel vaporization. When
hydrogen is added in the intake air ignition of hydrogen occurs immediately after the start of
injection. The heat released from hydrogen combustion compensates the heat necessary for
diesel fuel vaporization.
The brake specific heat consumption decrease (Fig. 8) is due to brake power increase.
The NO emissions are compared in Fig. 9 for the two cases: with and without hydrogen
addition. The experimental results that are shown on this figure are very complicated. This
fact prevents any final analysis and conclusions about NO emissions. When a diesel engine
runs with a small amount of hydrogen addition (repeatedly smaller than in the present
investigation) the NOx emissions are very lower in comparison with the case without
hydrogen addition (4). The NOx reduction with hydrogen addition might be attributed to
superior combustion characteristics of hydrogen that burns more rapidly and cleanly than
hydrocarbon fuels (4), because its amount is smaller and enters combustion reactions at higher
velocity, has lower activation energy, and incurs more molecular collisions than heavier
hydrocarbon molecules. These characteristics may not only improve combustion process but
also enhance transport processes reducing hot spots in combustion chamber that are one of the
major contributors to NOx emissions in IC engines.
Mihaylov, Barzev 7 11/02/2004
As shown on Fig 10, with hydrogen addition the engine smoke is higher. This behavior could
be explained by air-fuel ratio decrease (Fig. 12). The lower air-fuel ratio (in the case of
hydrogen addition) is due to the volumetric efficiency decrease (Fig. 11) due to the higher
thermal loading of engine elements. The higher thermal loading is due to heat utilization
efficiency improvement (Fig. 4). The engine elements with higher average temperature cause
air density decrease. In the present investigation particulate matter (PM) emissions were not
measured but such a measurement will be done in future investigation. Using the PM amount
(g/h) in the exhaust gases we would be able to evaluate the brake specific PM emissions
(g/kWh). It could be said with confidence that in case of hydrogen addition PM emissions
(g/kWh) would be lower due to brake power improvement.
CONCLUSION
Taking account the experimental results from the brake, emission and indicated diesel engine
performances the following conclusions can be drawn:
1. When the engine runs with hydrogen addition heat utilization efficiency improvement was
observed. The hydrogen addition influences the power improvement not only quantitatively
but qualitatively by the means of combustion improvement.
2. NO emissions are very complicated and more careful future investigation is needed.
3. When the engine runs with hydrogen addition the smoke increases because of air-fuel ratio
decrease. Future investigation is necessary to evaluate the specific particulate matter content
(g/kWh).
REFERENCES
(1) “Mihaylov M., K. Barzev, Influence of hydrogen addition on single cylinder direct
injection compression ignition engine parameters”, Proceedings, Volume 39, series 8, pp. 27
– 32, Transport and Mechanics, Rousse 2002.
(2) Matiewskii D. D, “Realization and influence of hydrogen addition on diesel engine
performance, “Ð”Ð²Ð¸Ð³Ð°Ñ‚ÐµÐ»ÐµÑ�Ñ‚Ñ€Ð¾ÐµÐ½Ð¸Ðµ”, pp. 53 – 56, February, 1985.”
(3) Heywood J., “Internal Combustion Engine Fundamentals”, McGraw-Hill Book Company,
1988
(4) Sherestha S. O., Bade A “Before Treatment Method for Reduction of Emissions in
Diesel Engines”, SAE Paper, 2000-0102791, 2000.


----------



## Boff

Hi Geoff,

OK, OK, one very last, last posting... :wink:



GBrapido said:


> i gerhard, i realise that was your last post and you will remain un-convinced, and i'm at the limit of my chemistry / physics with the combustion process
> 
> however i enclose some abstracts for you to look at.


Indeed, we are turning in circles now:

I have never doubted that oxygen enrichment on its own will improve the combustion process. But then oxygen enrichment requires to carry around _bottled oxygen!_ If you produce the oxygen while on the move by electrolysing water, the electrolysis process will cost you more energy than you can gain by increasing efficiency. Everything else would mean a violation of the law of energy conservation.

And here I am not "un-convinced". On the contrary, I am _absolutely convinced_ that the law of energy conservation still stands firm.

And one more remark regarding the abstracts: They are talking about adding an amount of oxygen that corresponds to 18% of the total air intake of the engine at full load. And no hydrogen. In my calculation here I have assumed 1%. Would I increase this to 18%, then my calculation would change in the following way:
The total amount of energy drawn off the engine for electrolysis would rise from 9.125 to 164.25 kWh. Which is more than the total chemical energy content of the used diesel fuel.
To get this much oxygen out of electrolysis, we would have to break up about 7.4 litres of water. In one hour!
So, because of 2. we would need a really huge electrolysis unit. One that will certainly not fit under the bonnet of any motor vehicle. However this would not even matter, as because of 1. the engine would simply grind to a halt.

Best Regards,
Gerhard

P.S: If you are really keen on oxygen enrichment, then forget about electrolysis. It is probably the least efficient method to produce oxygen.


----------



## Otto-de-froste

So..............


after all that can anyone tell me



Do a poodles eyes really pop out if you pick it up by the tail?


----------



## 110747

last posting as we seem to be going around in circles still.

it is nothing to do with breaking any laws of conservation of energy.

its very simple.

standard engine.

100% energy is added as fuel.

30% of that energy is converted to work.

15% of the energy is wasted as friction losses.

30% is wasted as exhaust heat

25% is wasted as hot water to the radiator etc.

so we have 100% energy balance.

now with hydrogen oxygen addition

100% is added as fuel.

38% is now converted to work due to improvements in the combustion which is not unreasonable as the previous papers have shown up to 15% improvement.

25% is now wasted as exhaust heat

22% is now wasted into the cooling system.

and the friction losses stay constant at 15%.

so again we 100% energy balance.

this is for break even using Gerhards numbers. So if we improve the combustion thermal efficiency by 9% we have a fuel saving potential.

this has been seen with 1% oxygen and 2% hydrogen added by volume.
and papers have been published by the SAE.

please explain to me where this breaks any laws of thermodynamics and laws of conservation of energy.

and finally a quote from a document published by the US government states.

In November 2007, the U. S. DOT, published a 94-page report titled, “GUIDELINES FOR USE OF HYDROGEN FUEL IN COMMERCIAL VEHICLES Final Report”

“A hydrogen injection system for a diesel engine produces small amounts of hydrogen and oxygen on demand by electrolyzing water carried onboard the vehicle. The electricity required is supplied by the engine’s alternator or 12/24-volt electrical system (see Section 1.5 for a description of electrolysis). The hydrogen and oxygen are injected into the engine’s air intake manifold, where they mix with the intake air. In theory, the combustion properties of the hydrogen result in more complete combustion of diesel fuel in the engine, reducing tailpipe emissions and improving fuel economy (CHEC, n.d.).”

“A hydrogen injection system for a diesel engine produces and uses significantly less hydrogen than a hydrogen fuel cell or hydrogen ICE, and does not require that compressed or liquid hydrogen be carried on the vehicle. The system is designed to produce hydrogen only when required, in response to driver throttle commands. When the system is shut-off, no hydrogen is present on the vehicle.”

“Limited laboratory testing of a hydrogen injection system installed on an older diesel truck engine operated at a series of constant speeds showed a 4 percent reduction in fuel use and a 7 percent reduction in particulate emissions with the system on (ETVC, 2005).”

those are statements written down by the US DOT, not me.

i also undersatnd the EPA are currently carrying out some tests which we will await with baited breath.

Geoff


----------



## Rapide561

*Hydracar*

Hi

Earlier today, I was chatting to a camper who told me he is taking his Rapido to a firm called "Hydracar" near Stoke on Trent to have a system fiited.

I asked him if he would come back to the site in a few weeks time - or at the very least phone me - with upto date mpg. The cost of the work is £700.00

Some of you may have read posts from myself in connection with a "K" registered DAF engined VanHool coach that had "something" done to it about 15 years ago. The DAF was new to the coach operator and had work done by a firm at Pontefract, which from what bit I understood, seems to sound a lot like what Hydracar are mentioning on their leaflet.

For the purpose of figures though.....

Cost of work - £700.00

My MPG - 25 mpg

Improvement of say 25% - new mpg is 31.25

Cost of diesel to remain constant at £6 per gallon.

Break even point would be about 14,000 miles of motoring.

Russell


----------



## Boff

Hi!



GBrapido said:


> So if we improve the combustion thermal efficiency by 9% we have a fuel saving potential.
> 
> this has been seen with 1% oxygen and 2% hydrogen added by volume.
> and papers have been published by the SAE.


Show me a publication about a dynamometer test: Same car, same engine. Run identical test cycles. First unmodified, then modified for 1% oxygen + 2% hydrogen via air intake, produced by an electrolytic cell powered by the car's alternator. If that test, documented according to scientific standards, and published in a renowned scientific journal, shows an efficiency increase of at least 9%, then I will believe it. Not a second earlier.

All the publications you have mentioned so far either show much lower efficiency increases, below breakeven, or don't involve electrolysis but _bottled_ hydrogen/oxygen.

And, last but not least: Should it really be possible to increase the overall efficiency of the engine, then I am still convinced that the same, if not a better, result could be achieved by simply optimizing the engine map for maximum efficiency. At a fraction of the cost.

Best Regards,
Gerhard


----------



## 110747

> All the publications you have mentioned so far either show much lower efficiency increases, below breakeven, or don't involve electrolysis but bottled hydrogen/oxygen.


In November 2007, the U. S. DOT, published a 94-page report titled, "GUIDELINES FOR USE OF HYDROGEN FUEL IN COMMERCIAL VEHICLES Final Report"

*"A hydrogen injection system for a diesel engine produces small amounts of hydrogen and oxygen on demand by electrolyzing water carried* onboard the vehicle. The electricity required is supplied by the engine's alternator or 12/24-volt electrical system (see Section 1.5 for a description of electrolysis). The hydrogen and oxygen are injected into the engine's air intake manifold, where they mix with the intake air. In theory, the combustion properties of the hydrogen result in more complete combustion of diesel fuel in the engine, reducing tailpipe emissions and improving fuel economy (CHEC, n.d.)."

"A hydrogen injection system for a diesel engine produces and uses significantly less hydrogen than a hydrogen fuel cell or hydrogen ICE, and does not require that compressed or liquid hydrogen be carried on the vehicle. The system is designed to produce hydrogen only when required, in response to driver throttle commands. When the system is shut-off, no hydrogen is present on the vehicle."

"Limited laboratory testing of a hydrogen injection system installed on an older diesel truck engine operated at a series of constant speeds showed a *4 percent reduction in fuel use *and a 7 percent reduction in particulate emissions with the system on (ETVC, 2005)."

*so they tested a system using electrolysis that resulted in a 4% reduction in fuel consumption.*

as i said before i cannot publish confidential data

the reason as i'm sure you're aware is that the patent rules don't allow the patent details to be in the public domain prior to pending status.


----------



## geraldandannie

If we accept the quoted figures from Geoff (4% achievable improvement in fuel consumption from onboard electrolysis), using Russell's figures, the payback mileage would be 87,500 miles.

Gerald


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## Zebedee

geraldandannie said:


> If we accept the quoted figures from Geoff (4% achievable improvement in fuel consumption from onboard electrolysis), using Russell's figures, the payback mileage would be 87,500 miles.
> Gerald


That's an awful lot of trips to Garda Gerald - and a factor that some folk seem to forget when they get all excited about mpg. :?

See >> here << for a very simple illustration.


----------



## Boff

GBrapido said:


> as i said before i cannot publish confidential data
> 
> the reason as i'm sure you're aware is that the patent rules don't allow the patent details to be in the public domain prior to pending status.


OK, then I will wait.

For the time being, some further reading on this topic:
US EPA on "Gas Saving and Emission Reduction Devices"
"Popular Mechanics" about the same topic.

Best Regards,
Gerhard


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## Rapide561

*Hydracar*

Hi

The Rapido has just left the site en route to Stoke for the work to be carried out. I shall see the owner later when he returns etc.

Russell


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## 110747

> If we accept the quoted figures from Geoff (4% achievable improvement in fuel consumption from onboard electrolysis), using Russell's figures, the payback mileage would be 87,500 miles.


not my figures, those are from US DEPARTMENT OF TRANSPORT.

And i agree whole heartedly with Gerald, i hear the sound of hammer and nail in convergance.

my stance has always been and and remains, i support the technology but i have never said that i support these devices and just because i support the technology does not mean that i think it will ever appear on main stream product.

there are simply way too many reasons not to use it compared with reasons to use it.

and large amounts of patents are being filed accross the world in this area just in case.

its like not believing in God but going to church just in case all these religious people are right after all.

Geoff

Geoff


----------



## Boff

Hi again,

OK, I will now try a completely different approach. One of which I hope it helps to distinguish between fuel saving measure that have (at least in theory) a potential to work, and the mere crackpot, or obviously fraudulent, schemes.

To achieve that, I will not discuss any technical details anymore. I will simply take a look at what actually happens in an engine, then take the fuel saving claims, and put them up against some very basic laws of physics, like the law of energy conservation.

Please note that I am not involved in any companies selling fuel saving devices, cars, or fuel. If any one of you still decides to buy any allegedly fuel saving gadget after reading this posting, so be it; I have neither any advantage or disadvantage from it. I am just a plain, honest scientist and do not like it if people are ripped off using any pseudo-scientific claims. This is the only reason why I am writing this.

So anybody who does not believe in the law of energy conservation, or the second law of thermodynamics, please do not read any further! :wink:

*1. Fuel and chemistry:*

*1.1 Combusting fuel:*
Any engine needs fuel, and air. Fuel is a mixture of different hydrocarbons, substances that mainly consist of hydrogen and carbon in various compounds. Air is a mixture of different gases, mainly nitrogen (78%) and oxygen (21%). If fuel burns, then a chemical reaction between the hydrogen/carbon, and the oxygen from air takes place. This reaction is what scientists call "exothermal", which simply means it releases energy in form of heat.

Now the amount of energy that is released if two hydrogen atoms react with one oxygen atom, to form one water molecule, is a) fixed and b) well-known. As is the energy that is released if one carbon atom forms with two oxygen atoms a carbon-dioxide molecule. We also know how much hydrogen and carbon there is in a volume of fuel, so if we assume an ideal case in which all the hydrogen and all the carbon react, then we can easily determine the total amount of energy that can and will be released during this chemical reactions. This amount of energy per litre of fuel is called _"calorific value"_. For diesel fuel the calorific value is 35.3 Megajoule per Litre (MJ/l), for petrol it varies a bit with the quality (RON number), a typical value for (European) Regular petrol is 34.6MJ/l.

This chemical reaction, of course, takes place under the law of energy conservation. Which means that there is absolutely no way of getting more energy out of it than is said above. Which means that:

*Any claims to get more energy than the calorific value out of fuel, violate the law of energy conservation, and are therefore false!*

*1.2 Reversible processes:*
In theory, at least, every chemical reaction is reversible. However, the reverse reaction to an exothermal reaction is always an endothermal reaction, which means that energy is consumed during the reaction. And of course, due to the law of energy conservation, the amount of energy that is released in an exothermal reaction is precisely the same as the amount that has to be "invested" in the reverse reaction. This principle is of course not only valid for fossil fuels, but for all possible chemical reactions. Including the ones between hydrogen and oxygen. So:

*Any claims to split up water into its components hydrogen and oxygen, using less energy than is released when the two recombine again, violate the law of energy conservation, and are therefore false!*

*2. The combustion process in an engine:*
So far we have assumed that the fuel burns up completely. In a real-world engine this is of course not completely true. No matter whether a petrol or diesel engine, the combustion will not be 100% complete, small amounts of fuel will not react. These will however not just disappear, after all, there is not only a law of energy conservation but an equivalent law of mass conservation. Which means that all fuel components that have not reacted in the engine, will get into the exhaust system. Typical forms of fuel residue that can be found in the exhaust are hydrocarbon molecules, carbon monoxide, and in case of diesel engines, soot.

Engine developers have always tried to keep the amount of fuel residue in the exhaust as low as possible, not only because of engine efficiency but also to keep emissions low. After all, especially carbon monoxide is highly toxic. With the result that modern diesel engines burn up more than 99% of the injected fuel. Petrol engines are slightly behind with about 98%, this is because a certain amount of unburnt fuel is needed for the operation of the catalytic converter, however after the catalytic converter petrol exhaust gases contain even less fuel residue than those of diesels, about 0.2%.

Of course it is not possible to make the combustion process more complete than 100%. And as (modern) engines already achieve a 98 to 99% complete burn, this means that:

*Any claims to increase the efficiency of modern engines by more than 1-2% by means of making the combustion process "more complete", violate the laws of energy and mass conservation, and are therefore false! All claims to increase engine efficiency this way by up to 1-2% while maintaining or even improving emission values, are also false!*

*2.1 Fuel injection:*
There are claims that significant efficiency increases can be achieved by optimizing the fuel injection process, especially with Diesel engines. In theory, if the fuel that is injected forms too large droplets, it could happen that these do not "burn through to the core", leaving a residue of unburnt fuel. Therefore diesel engine designers aspire towards ever smaller injection nozzles with ever higher pressure. And they reduce the fuel's viscosity by heating it up. Now it might be possible that an old, worn-out engine indeed burns only 90% of the fuel, and in this case efficiency gains of up to 10% might be feasible. However for modern engines burning already 98-99% of the fuel, this means:

*Any claims to increase the efficiency of modern engines by more than 1-2% by means of "optimizing" the fuel injection, or the fuel's consistency, violate the laws of energy and mass conservation, and are therefore false!*

*3. The role of Nitrogen:*
Ideally, an engine would run on only fuel and pure oxygen. Now for space flight this is actually done; as there is no air available in outer space the oxygen has to be carried anyway, so better take it pure. We on firm soil with our cars, however, still have to stick around with ordinary air; unless we want to carry bottled oxygen with us. And air contains only 21% of oxygen, and 79% nitrogen (and other gases, for simplicity considered as nitrogen, too).

Now under the conditions in an ordinary engine nitrogen is almost inert, means that it does take almost no part in the combustion process. It does however "carry away" some of the heat that is generated in the engine. But how much?

If we burn 1kg of Diesel fuel we need 3.65kg oxygen. If using air, then together with this amount of oxygen 11.91kg of nitrogen will be "flushed" through our engine. We know the difference in temperature between the air taken in and the exhaust gases, this is typically about 500 Kelvin (K). So if we burn 1kg of Diesel, we heat up the 11.91kg of nitrogen by 500K. The heat capacity of nitrogen is 1,040J/(kg*K), so to heat up this amount of nitrogen that much we use 6,193 kilojoule of energy. By burning the 1kg Diesel, an energy of 42.5 Megajoule is produced. Which means that the nitrogen cannot carry away more than 14.6% of the total released energy.

Would we run our engine with pure oxygen instead of air, we would for comparison however start with the efficiency of the plain, unmodified engine running on air. Therefore we have to start our percentage calculation from the lower value, which is 42.5MJ-6.193MJ=36.307MJ. Adding the 6.193MJ (=6,193kJ) would mean to add 17.1%. So the maximum possible increase in efficiency by running an engine on pure oxygen instead of air is 17.1%. Which means that:

*Any claims to increase engine efficiency by more than 17.1% by running it on pure oxygen instead of air, violate the law of energy conservation, and are therefore false!*

*4. Partial oxygen enrichment:*
Of course, the gain in efficiency is even lower if we do not replace all nitrogen by oxygen. For example, if we manage to double the amount of oxygen in the air flow, we will reduce nitrogen from 79 to 58%. In this case still 4.547MJ would be carried away by the remaining nitrogen, so the maximum possible efficiency increase would only be 4.5%

Increasing oxygen levels by 18%, as suggested in one of the publications quoted, would lead to 3.9% more efficiency.

Increasing oxygen levels by only 1%, as done in a previous calculation, would lead to only 0.22% more efficiency.

Which means:

*Any claims to increase engine efficiency by more than the above mentioned values by partial oxygen enrichment, violate the law of energy conservation, and are therefore false!*

*5. Thermal efficiency:*
I am looking at Diesel engines here, because they are most common in motorhomes. The Otto process which petrol engines run on differs slightly. The Diesel engine works on a thermodynamic cycle called the Diesel cycle. Details see here. There you also find the formula for the thermal efficiency of this process. From there you can see that this efficiency solely depends on the compression ration, the cut-off ratio (ratio between end and start volume for the combustion phase), and the heat capacity ratio. None of the three parameters can be influenced by any modifications on the air intake or the fuel injection. Which means that:

*Any claims to increase the thermal efficiency of an engine without modifying the compression ratio, are false!*

*6. "HHO fumigation":*
This brings us back to the original topic. There are claims that by adding a so-called stoichiometric mixture of hydrogen and oxygen to the air intake, the engine's efficiency can be increased.

*6.1 Effects of HHO fumigation on oxygen levels:*
I have however shown in an earlier posting that none of the additional oxygen is in fact available to burn the fuel, because it is all consumed by the hydrogen. True, a certain amount of air nitrogen will be replaced, however a similar amount of air oxygen will be replaced, too. So in this case, all in all _less oxygen_ is available to burn the fuel. This could in theory have detrimental effects on the fuel burn rate. However, with all devices currently on the market the amount of produced HHO gas is so small that the effects can be neglected.

*6.2 Effects on nitrogen levels:*
Of course, the amount of nitrogen will be reduced, too. However it will be replaced by substances which have approximately the same heat capacity _per volume_, so no difference is made regarding heat extraction.

*6.3 Effects on thermal efficiency:*
As explained above, there can be none.

*6.4 Effects of HHO fumigation on fuel burn rate:*
Although, as explained earlier, there is no reason why HHO fumigation should influence the burn rate. Even if it did, the efficiency gain in modern engines would be limited to 1-2%. Clearly less than the inevitable efficiency loss caused by the electrolysis process.

If there are any remaining claims regarding significant fuel savings, then please tell me.

Some further reading:
Tony's guide to Fuel saving

Best Regards,
Gerhard


----------



## 110747

> 5. Thermal efficiency:
> I am looking at Diesel engines here, because they are most common in motorhomes. The Otto process which petrol engines run on differs slightly. The Diesel engine works on a thermodynamic cycle called the Diesel cycle. Details see here. There you also find the formula for the thermal efficiency of this process. From there you can see that this efficiency solely depends on the compression ration, the cut-off ratio (ratio between end and start volume for the combustion phase), and the heat capacity ratio. None of the three parameters can be influenced by any modifications on the air intake or the fuel injection. Which means that:
> 
> Any claims to increase the thermal efficiency of an engine without modifying the compression ratio, are false!


wrong wrong wrong wrong wrong.

from your very own link in this quote it says.



> *This formula only gives the ideal thermal efficiency. The actual thermal efficiency will be significantly lower due to heat and friction losses*. The formula is more complex than the Otto cycle (petrol/gasoline engine) relation that has the following formula;


so as you will see from reading the data correctly by increasing the efficiency of combustion process in terms of thermal losses in the pahse of the engine where work is actually done the thermal efficiency can be improved

where do you think all the heat up the exhaust and into the cooling water comes from.

Geoff


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## Rapide561

*Economy*

Hi

A lot of what is being said is way above me in terms of science etc.

However, I am proposing to start a new thread - something along the lines of "Rapido after Hydracar work" etc.

The owner is happy for me to take a couple of pics. He returned yesterday with the van and the first thing he noticed was the van seemed more "nippy".

It is a Rapido low line with 2.8 Ducato.

Russell


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## 110747

Hi Russell.

i agree, i'm looking forward to the results, good or bad as the more data we get on this stuff the better.

if good results it will be that the test wasn't scientific and if bad results it will be i told you so.

even if he's delighted with it he won't be believed.

but i don't care as i have made my position very clear.

go ahead start a new thread and i promise not to post on it :lol: 

Geoff


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## Rapide561

*Hydra*

Geoff - of course you can post on it!

One thing that sticks in my mind though is how similar the system sounds to that fitted to the K reg coach. The fuel economy of the coach was up by about 10%

Right, I shall speak to the owner tomo and get a pic too.

Russell


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## Boff

GBrapido said:


> so as you will see from reading the data correctly by increasing the efficiency of combustion process in terms of thermal losses in the pahse of the engine where work is actually done the thermal efficiency can be improved


OK, sorry, it seems that the term "Thermal Efficiency" in my native language (German) is used in a different way than in English. Or that physicists use it in a different way than engineers?

Anyway, what I meant was the _efficiency of the thermodynamic cycle_, which excludes losses due to friction etc.

OK, if we use the term now in the sense that you mean it, then from my last posting you can clearly see how much this efficiency can be increased: 

More complete combustion: Max. 1-2%
Running engine on _pure oxygen_: Max. 17.1%

The remaining heat losses are inevitable due to the second law of thermodynamics. Any attempt to reduce these losses any further would require to increase the upper temperature level of the thermodynamic cycle, which in a diesel engine would go along with an increase in compression.

Any other changes to the burn process might increase the speed of combustion. The engine's cylinder behaves - during the combustion phase - as an "isolated system" in thermodynamic sense. (Except if it is in desperate need for repair...) And in an isolated system the temperature increase is determined solely by the _amount_ of energy released, in no way by the speed of energy release.

That's it for me. May now the Hawthorne effect do its job on Russel's friend's van. :wink:

Best Regards,
Gerhard


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## 110747

> Any other changes to the burn process might increase the speed of combustion. The engine's cylinder behaves - during the combustion phase - as an "isolated system" in thermodynamic sense. (Except if it is in desperate need for repair...) And in an isolated system the temperature increase is determined solely by the amount of energy released, in no way by the speed of energy release.


once again, completely wrong.

i'm gonna try and keep this simple.

injection of the fuel begins at 20deg before TDC.

during combustion of the fuel there are 3 phases.

1st phase is called the delay.

during this phase the droplets of fuel are vaporized and the fuel is heated to its ignition point, whereupon multiple ignition points are established in the charge where fuel is in contact with oxygen at the correct proportion.
although there is sufficient air in the charge the actual ratio of fuel to oxygen in the charge will vary from 100% fuel to oxy to 100% oxy to fuel. depending on droplet size, combustion chamber shape, squish, swirl, and many other factors including the type of fuel etc.

during the delay the crank continues to rotate and as it goes beyond TDC we then enter pahse 2 of the process.

this phase is called the rapid combustion period.

during this phase the multiple ignition points spread to the whole charge and this is basically the bang.

this phase will be complete by about 20Deg after TDC.

The next phase takes place from 20 deg after TDC to about 140Deg after TDC which is when the exhaust valve opens.

the remaining fuel is now ignited. The rate of this combustion is determined by the amount of oxygen that the remaining fuel can find to allow combustion.

This phase continues after the exhaust valve is open but no work is done as the pressure will now be used for exhaust extraction .

so the combustion can only do work between TDC and 140deg after TDC.

the delay has very little effect on power production as most of it occurs before TDC.

so we focus on phase 2 which is the period of rapid combustion.

each droplet of fuel has a vapour covering its outside surface that is in contact with the oxygen. as the surface vapour burns off the droplet there is less oxygen available and combustion is slowed untill new oxygen can be brought into contact with the vapour. By increasing the combustion temperature and reducing the droplet size we get a better combustion of the fuel. the evaporation rate of the drops determines the rate of combustion of the fuel at this phase. As hydrogen is a gas it is already in a vapour state and will burn very quickly.

as the hydrogen now takes over the role of combustion initiator in the mix and is producing heat, this heat helps to vaporize the diesel fuel and increase its rate of combustion.

addition of oxygen into the mix also helps in this phase to get the fire going quickly.

so what you say, we now have faster pahse 2 combustion, how does this equate to more power.

well as we know this phase ends at about 20 Deg after TDC.

the highest compression in the engine is at TDC, so the addition of heat at this point will yield more power.

as the compression gets lower as it approaches 20 Deg after TDC the heating will have less effect than at TDC, so we want to add as much heat as we can whilst the engine is as near to TDC as possible.

so the aim is complete phase 2 as soon as possible and the addition of hydrogen and oxygen help to speed up phase 2.

as we have now reduced the time of phase 2 we now have a bit more time for phase 3.

this allows the remaining fuel to be burned while still in the power generating zone up to 140Deg after TDC.

alot of the fuel will be burned still after the exhaust valve opens but we still have more power than before.

Nitrogen does not get flushed through the engine, it absorbs heat and reacts with some of the oxygen to produce NOX emmissions. by reducing the nitrogen content we increase the amount of oxygen available for combustion as its now not busy making NOX.

during the combustion phase a considerable amount of the heat generated is lost to the walls of the engine, the rate of heat transfer is fixed and the quicker the combustion the less time heat has to transfer into the cylinder walls resulting in more heat being used for expansion.

so by modifying the combustion process we can increase the thermal efficiency of the engine.

this means more heat is used to generate power and less is wasted.

for example take swirl.

if we increase the swirl in the charge we generate more turbulance inside the combustion chamber during phase 2.

this causes more oxygen to be fed to the vapour surrounding the droplets and promotes faster combustion in phase 2.

its like stirring your tea puts more fresh hot water in contact with the leaves promoting faster infusion from leaf to water.

Geoff


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## Boff

GBrapido said:


> i'm gonna try and keep this simple.


Unfortunately, this means for me to dig a bit deeper into the physics, but so be it. All of what I am going to say is under the - entirely hypothetical - assumption that there is an aftermarket "fuel saver" device that can produce sufficient amounts of hydrogen and oxygen to make a difference.



GBrapido said:


> 1st phase is called the delay...
> 
> during this phase the droplets of fuel are vaporized and the fuel is heated to its ignition point, whereupon multiple ignition points are established in the charge where fuel is in contact with oxygen at the correct proportion.
> although there is sufficient air in the charge the actual ratio of fuel to oxygen in the charge will vary from 100% fuel to oxy to 100% oxy to fuel. depending on droplet size, combustion chamber shape, squish, swirl, and many other factors including the type of fuel etc.


Agreed.



GBrapido said:


> during the delay the crank continues to rotate and as it goes beyond TDC we then enter pahse 2 of the process.
> 
> this phase is called the rapid combustion period.
> 
> during this phase the multiple ignition points spread to the whole charge and this is basically the bang.
> 
> this phase will be complete by about 20Deg after TDC.


Partially agreed. In fact, in a Diesel engine the combustion starts already before TDC, but not at a significant rate. (Hopefully, at least.)



GBrapido said:


> The next phase takes place from 20 deg after TDC to about 140Deg after TDC which is when the exhaust valve opens.
> 
> the remaining fuel is now ignited. The rate of this combustion is determined by the amount of oxygen that the remaining fuel can find to allow combustion.
> 
> This phase continues after the exhaust valve is open but no work is done as the pressure will now be used for exhaust extraction .
> 
> so the combustion can only do work between TDC and 140deg after TDC.


Partially agreed. Fact is that even if there is any fuel left when the exhaust valve opens, the combustion will die rather quickly as the pressure and with it the temperature drops below ignition point. And no residual pressure is needed for exhaust extraction, as the exhaust gases are squeezed out by the piston anyway.



GBrapido said:


> the delay has very little effect on power production as most of it occurs before TDC.


Not agreed!

If the delay - for whatever reason - is too short, then it will have a significant, and rather devastating, impact on both efficiency and engine life. Because then a significant amount of fuel will already combust before TDC, creating pressure that acts against the piston on its way to TDC. Which means that any tampering with the burn process must be accompanied by careful readjustment of the injection timing (or the ignition timing in a petrol engine).



GBrapido said:


> as the hydrogen now takes over the role of combustion initiator in the mix and is producing heat, this heat helps to vaporize the diesel fuel and increase its rate of combustion.


This is your first in a series of misconceptions. Fact is that hydrogen has a much higher ignition point than Diesel fuel, 560 degrees C vs. 300. So when the temperature rises during the compression phase, it will be the Diesel that ignites first.



GBrapido said:


> the highest compression in the engine is at TDC, so the addition of heat at this point will yield more power.


This is your second misconception, but to explain that I have to dig into the thermodynamics now.

Just to explain the effects of ignition timing during phase 2 and 3, I will first look at an ideal engine. Which means that I assume the fuel burns only after TDC, burns 100% before exhaust valve opening, there are no heat losses to the walls, and the fuel-air-mix behaves as an ideal gas. In a second stage I will take account for the differences to a real engine.

OK, what happens: From TDC down to the moment the exhaust valve opens, the engine will resemble a closed system, means that no _matter_ can leave or enter. The only thing that can change on a macroscopic scale is the volume, this can grow by pushing the piston down. (Which is what is intended to happen, of course.) This means the amount of fuel-air-mix is fixed. As a consequence, also the heat energy that this amount of fuel-air-mix will release at a 100% burn, is fixed.

Now what happens when the fuel ignites: A fixed, pre-determined amount of energy will be released as heat, and it will act on an equally fixed, pre-determined amount of (ideal) gas. Now ideal gas has a constant heat capacity, so it will increase its temperature by a fixed amount, which is heat capacity times mass times released energy. Proportional to the temperature the pressure will increase. This pressure, multiplied with the piston's surface area, resembles a force. As we have also for the time being excluded any heat losses, the only way for this system to change, once the mix is ignited, is a so-called _adiabatic expansion_.

To calculate the energy, the mechanical work that the engine produces, we now have to integrate (mathematically) the force acting on the piston (and via it on the crankshaft) over the full range the piston travels from TDC to exhaust valve opening. A range which is of course pre-determined by the engine design. As all the parameters are constant, and the integration's start and stop position are constant, too, the result will of course also be a constant. Which means:

In an ideal engine, the timing of the combustion does absolutely not matter, as long as it takes place between TDC and opening of exhaust valve!

Now let us look at a real engine, which means that I will step by step consider the differences between ideal and real thing, and how effects of combustion timing might "sneak in":

*Non-ideal gas:*
As the fuel-air-mix under the conditions in an engine does not resemble an ideal gas, the heat capacity is not constant. Instead it will increase with temperature. At typical burn temperatures of around 2000 degrees C it will be about 30% higher than at room temperature. This means that any given amount of heat will induce less temperature increase than in an ideal gas, and therefore less pressure increase. However, still the maximum temperature is solely determined by the amount of gas and the released energy. Which means that this "real gas factor" will decrease maximum temperature and with it efficiency. But even if we consider a real gas we have not yet any influence of combustion timing on efficiency.

*Heat losses through the engine walls:*
This will bring us to your third misconception:


GBrapido said:


> ...the rate of heat transfer is fixed...


No, the rate of heat transfer is not fixed! Heat transfer is always driven by temperature difference. The bigger the temperature difference, the more heat is transferred. Of course, heat transfer also depends on time. And now combustion timing really comes into effect, however just the other way than you think: If we only look at heat losses, then it would be best to delay the combustion as much as possible! Which would however cause trouble with incomplete burn, but that will be dealt with later.

*Pre-mature combustion:*
I use this term to describe all combustion processes that occur before TDC. As I have said before, all energy that is released before TDC will not only be lost, it will even counteract the piston's motion. Nevertheless, as with real fuel there is a combustion delay, the engine timing makes sure that ignition starts a little bit before TDC. 
So, if we really somehow manage to speed up phase 2, then we must be very careful about ignition timing. Otherwise we will certainly loose efficiency, and sooner or later the whole engine.

*Incomplete combustion:*
If any fuel remains uncombusted when the exhaust valve opens, then the energy contained in this fuel is of course lost. So if increased burn speed could have any effect on engine efficiency, then here. However, this has nothing to do with thermodynamics anymore, it is solely a matter of engine management. So we can already state that:

*If there is any way of improving engine efficiency by speeding up combustion, then this is solely via reducing the amount of unburnt fuel.*

Nevertheless, here you have a point:


GBrapido said:


> ...we now have a bit more time for phase 3.
> 
> this allows the remaining fuel to be burned while still in the power generating zone up to 140Deg after TDC.


However, all engines built in the last 40 years or so, provided they are in a good condition, burn up at least 95%, usually between 98 and 99%, of the injected fuel before the exhaust valves open. Which limits the possible efficiency increase to these values. And there is a much much easier way of giving phase 3 more time, than tampering with phase two timing: Let the engine run a little slower!

Because while the time between TDC and end of phase 3 is proportional to the engine's RPM, the combustion time is not.

And one last thing:


GBrapido said:


> by reducing the nitrogen content we increase the amount of oxygen available for combustion as its now not busy making NOX.


In theory this is true. However, and this is your misconception number four, if we introduce a _stoichiometric mixture_ of hydrogen and oxygen into the air intake, we will reduce not only the nitrogen content, but in proportion also the oxygen content of the air. So all in all there will be _less_ oxygen available for combusting the same amount of fuel, not more.

So my conclusion as a scientist: The science behind such fuel-saving claims simply does not work out. They are all based on misinterpretations, or ignorance of, basic scientific principles.

Best Regards,
Gerhard


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## 110747

> Partially agreed. In fact, in a Diesel engine the combustion starts already before TDC, but not at a significant rate. (Hopefully, at least.)


wrong.

phase 2 or the period of rapid combustion occurs entirley after TDC if the delay is correct, and this is determined by a few important factors.

the beginning of phase 2 is the point of a visible flame and when the pressure in the cylinder is above the pressure of compression alone.



> the combustion will die rather quickly as the pressure and with it the temperature drops below ignition point


wrong again the exhaust temperature will be at about 700Deg C so will not drop below your quoted flashpoint temps.



> This is your first in a series of misconceptions. Fact is that hydrogen has a much higher ignition point than Diesel fuel, 560 degrees C vs. 300. So when the temperature rises during the compression phase, it will be the Diesel that ignites first.


wrong

the temperature of the charge is above 700 deg c due to some exhaust remaining in the cylinder and other residual heat ( metal on piston crown over 800 Deg C ) and as the hydrogen is compressed before the diesel is injected it is already hotter than the drops of fuel.

diesel as a liquid will not burn, it has to first be vaporised by the heat in the cylinder this takes time and energy also resulting in the hydrogen igniting first.



> Now what happens when the fuel ignites: A fixed, pre-determined amount of energy will be released as heat, and it will act on an equally fixed, pre-determined amount of (ideal) gas. Now ideal gas has a constant heat capacity, so it will increase its temperature by a fixed amount, which is heat capacity times mass times released energy


once again, half a story.

it is not a constant volume combustion process.

quote from Sir Harry Ricardo

" the ideal combustion process

The rate of pressure rise during the period corresponding to constant volume combustion should be as rapid as possible without however exceeding a certain value for a particulare size and design"

as i'm sure you're aware Boyles law states p X V = constant.

so as the volume increases the pressure is decreasing, so we have to increase the pressure at a greater rate than the volume is expanding.

the faster phase 2 is carried out the more work is done and the rate of pressure decay is less.



> No, the rate of heat transfer is not fixed!


i knew as i wrote it you would pick it up, i was merely putting it asside to keep things simple.



> The bigger the temperature difference, the more heat is transferred


wrong the delta T only determines the rate of heat transfer not the quantity. that is time dependant.

so for a fixed delta T a reduced time will result in less heat transfer.



> the engine timing makes sure that ignition starts a little bit before TDC.
> So, if we really somehow manage to speed up phase 2, then we must be very careful about ignition timing. Otherwise we will certainly loose efficiency, and sooner or later the whole engine.


Wrong again.

the delay controls the point of the beginning of phase 2. phase 1 does not release energy to do work. merely to heat and change the diesel from a liquid to a gas.

the delay period is determined by the heat available in the cylinder at the point of injection initiation.



> If there is any way of improving engine efficiency by speeding up combustion, then this is solely via reducing the amount of unburnt fuel.


wrong



> However, all engines built in the last 40 years or so, provided they are in a good condition, burn up at least 95%, usually between 98 and 99%, of the injected fuel before the exhaust valves open


completely irrelevant as i continue to try to explain it is about reducing the losses in the combustion process.

once again, 100% fuel in 30% work out.

there are other factors which you also conveniently ignore.

such as the production of NOX and the energy wasted doing this.

by increasing the speed of combustion in phase 2, there is less time for the production of NOX which also uses heat energy for the chemical reaction.

so more wasted heat can be used for work rather than producing NOX.

so what you are saying is that the combustion process cannot be improved and it is therefore perfect.


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## 117315

This is my first post on motor home facts and I guess I'm diving in the deep end but here goes.
Firstly I would like to thank all involved for making this a constructive debate, all to often there things turn into a mud slinging match.
I agree that very little useful energy can be gained from a couple of bits of scrap stainless steel in a jam jar. For any really useable energy to be produced a much larger surface area is required and of course much more energy to drive it.
If we are only talking about powering a shoe box on wheels then there is very little area to store the required energy or fit a suitable sized electrolyser but then even a small increase in power would be noticable.
But if we are talking about a reasonable sized M/Home then we already have the room to carry a few AGM batteries, solar panels and some where to fit a decent sized electrolyser. The energy to recharge these batteries can be from the solar panels, shore power when hooked up and regenerative braking when travelling.
It wouldn't take an electrical genius to design a circuit triggered by the brake light/exhaust brake or a vacuum switch on a petrol engine to trip a relay to divert alt power to these batteries.
Another few points that seem to have been missed is the amount of piston movement in relation to crankshaft degrees before and after TDC.
Certainly catastrophic engine damage would happen if every drop of combustible fuel was to explode simultaneously at TDC, fortunately that doesn't happen, an explosion starting a few degrees before TDC is not being compressed as the piston has already finished it's upward travel, the inertia within the engine mechanicals will drive the crank shaft past this point so the rapidly expanding gas can push the crankshaft around via the piston and conrod. The power is achieved within this first 90deg of rotation, the earlier the better. More power can be transmitted in the second 90deg but not near as effectively. Riding a push bike simplifies this explanation.
The second point missed is the work the 2 parts hydrogen and one part oxygen does. It's explosive power is only 1/3 that of petrol, *  but in doing so it creates water, naturally at the point combustion the heat is so great that it is in the form of superheated steam. Some of the heat energy that is created in the explosion is absorbed by the water, thus reducing the amount of NOX created with the already reduced amount of nitrogen present.
This superheated steam must release it's energy to return to water. This heat energy is released as the pressure begins to drop, maintaining this high pressure against the piston for a longer duration of the power stroke.
 *  (I don't know what the ratio to diesel is as the burn rate is different and many other factures must be considered).

Hopefully I have only added to this debate and not inflamed it. (Bad pun)
Aussie Terry


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## Rapide561

Hello

The chap with the Rapido has left the site now but is back in a couple of weeks. I will relay his findings after having had "something" done at HydraCar near Stoke. I will add a pic. 

Russell


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## Boff

Hi!



GBrapido said:


> phase 2 or the period of rapid combustion occurs entirley after TDC if the delay is correct


Phase 2 yes, Phase 1 (the delay) however starts before TDC. And if we add any agent that is supposed to speed up phase 2, and the very same agent is already present in phase 1, then it is quite likely that this agent will speed up phase 1, too. So, after modification, engine timing should be carefully checked and adjusted, to avoid efficiency losses and engine damage.



GBrapido said:


> the temperature of the charge is above 700 deg c due to some exhaust remaining in the cylinder and other residual heat


If that is so, then the hydrogen will already combust before TDC. Very, very bad, if there are any significant quantities of it available. This is just what I mentioned before: If the charge contains significant amounts of hydrogen, and its temperature exceeds 560 degrees C before TDC, then this hydrogen will ignite. And as you rightly say, hydrogen burns much faster than diesel.

And indeed, in a Diesel engine the charge reaches a temperature of about 700 to 900 deg C at TDC, however mainly not due to residual heat as you said but due to _compression_. It is now rather difficult to guess at which point the 560 deg C ignition temperature of hydrogen will be exceeded, but it will certainly happen significantly before TDC. It is a different story in a petrol engine, though.

Now about some more misconceptions and misunderstandings:



GBrapido said:


> it is not a constant volume combustion process.


No it is not. And I never said that. I said it is an _adiabatic expansion_, which is - as the word "expansion" says - not a constant volume process.



GBrapido said:


> as i'm sure you're aware Boyles law states p X V = constant


Boyle's law does not apply here, as neither the temperature nor the amount of particles (or moles) is constant during combustion. We would have to use the full _Van der Waals equation_ here:

(p + n^2*a/V^2)*(V-n*b) = n*R*T

I will spare you the details now, but for a theoretical, "ideal" engine I have done this. And the result is that burn timing does not matter.

Now I am fully aware that your point is that by optimising the burn process a "real" engine can be brought closer to the theoretical ideal, and will therefore be more efficient. So I have tried to dig deeper into this. However I found that if I check a number of n different sources, I find at least n+1 different opinions of how the ideal burn process should look like. Almost like lawyer's talk... :wink:

There are however some clear tendencies in current Diesel engine development: Firstly, engine developers try to increase _injection pressures_ while at the same time using smaller injection nozzles. This leads to a finer spray, smaller droplets and therefore certainly to an accelerated burn. Modern Common-Rail injection systems use up to 1,800 bar injection pressure, and systems with pressures up to 2,500 bar exist as prototypes. On the other hand however, there is a clear tendency towards using multiple injection events, which would actually spread the burn process over a longer time.

I simply cannot afford to spend any more time on this, so from now on I will not exclude the possibility anymore that for a real engine burn process timing _might_ have an influence on engine efficiency other than merely reducing the amount of unburnt fuel. (Though I still consider it as speculative and would expect sound scientific evidence...)

One thing however remains perfectly clear: If there is any efficiency gain, then this must go along with the peak temperature (and pressure) level reached earlier, and probably also be higher, during the burn process.

And this brings me to some other aspects:



GBrapido said:


> so for a fixed delta T a reduced time will result in less heat transfer.


Correct. And if we reach the peak value of delta T earlier, and keep it up for the same time, this will result in more heat transfer. Which means: If phase 2 is accelerated, then the peak temperature in the cylinder will be reached already at an earlier stage. So, while delta T remains the same (or is maybe even increased), the time that this delta T can act on the engine walls is prolonged. *Ergo, more heat losses.*



GBrapido said:


> ...production of NOX...


I have indeed ignored energy losses through NOX production so far, and for two reasons:

Firstly, because the amount of energy that is wasted here, and therefore the savings potential, is below 1% for any engine that fulfills current emission standards. NOX production is more a matter of pollution, than of efficiency.

Secondly, the _rate_ of NOX production is (exponentially) temperature-dependent (Arrhenius equation). So to reduce total NOX it would be better to keep combustion temperatures low as long as possible.

However,


GBrapido said:


> ...by increasing the speed of combustion in phase 2...


... the temperature level in the charge rises faster, and maybe to a higher level. So NOX production starts earlier, operates at a higher rate, and stops at the same time as before. *Ergo, more NOX will be produced.*

Now this might at least partially be compensated by the reduction of available nitrogen in the air intake. However, while adding a stoichiometric mixture of hydrogen and oxygen will certainly displace a part of the nitrogen, it will in proportion also displace a part of the oxygen. And as all the additional oxygen will be used up by the hydrogen, the total amount of oxygen available for _fuel burning_ will be reduced. And how a reduction of available oxygen can lead to accelerated burn, that I still fail to understand...

The HHO mix will however, as Terry rightly says, end up in form of superheated steam. Now the specific heat capacity of steam is about twice as high as that of air, so the heat losses via the exhaust gases will increase, not decrease.

Conclusion:

It is highly speculative, whether an accelerated phase 2 burn can lead to an increase in thermal efficiency. It is however certain that any such increase will go along with increased heat losses and increased NOX production. And if _self-produced_ hydrogen-oxygen mix is used for that, then _per volume percent added mix about 8% of the engine's power output_ must be diverted for electrolysis. Whether the alleged thermal efficiency increase can outweigh these additional losses, remains even more speculative. I do remain extremely sceptic here.

@ Terry:



Teza37 said:


> But if we are talking about a reasonable sized M/Home then we already have the room to carry a few AGM batteries, solar panels and some where to fit a decent sized electrolyser. The energy to recharge these batteries can be from the solar panels, shore power when hooked up and regenerative braking when travelling.


Of course in theory this is possible. However, if you equip your van for regenerative braking, then you would need to retrofit a powerful electric generator anyway. (The standard alternator is far too weak for that, and it is separated from the wheels anyway as soon as you hit the clutch.) And if you had such a generator, you could also run it as an electric motor, directly from your battery. (Which is called hybride drive. My normal car has one.) So all the electrolysis stuff would be totally obsolete from the very beginning, a pure waste of energy.



Teza37 said:


> This superheated steam must release it's energy to return to water. This heat energy is released as the pressure begins to drop, maintaining this high pressure against the piston for a longer duration of the power stroke.


No, it will not.

While in the engine, the temperature will be well above the dew point, so it will like all the other components of the charge just follow the adiabatic expansion curve. And it is of vital importance for both engine and exhaust system that it does just that and only condensates after having left the exhaust. If steam condensates within the engine or exhaust, then it will form a rather corrosive acid.

Best Regards,
Gerhard


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## 117315

Hi Boff
Not quite sure I've got the quoting part right, apologies if I've messed it up.



GBrapido said:


> phase 2 or the period of rapid combustion occurs entirley after TDC if the delay is correct





Boff said:


> _Phase 2 yes, Phase 1 (the delay) however starts before TDC. And if we add any agent that is supposed to speed up phase 2, and the very same agent is already present in phase 1, then it is quite likely that this agent will speed up phase 1, too. So, after modification, engine timing should be carefully checked and adjusted, to avoid efficiency losses and engine damage._


Yes, this is correct for more reasons than you have stated here. The injection timing and quantities could be adjusted to utilise the produced waters effect on NOX production



GBrapido said:


> the temperature of the charge is above 700 deg c due to some exhaust remaining in the cylinder and other residual heat





Boff said:


> _If that is so, then the hydrogen will already combust before TDC. Very, very bad, if there are any significant quantities of it available. This is just what I mentioned before: If the charge contains significant amounts of hydrogen, and its temperature exceeds 560 degrees C before TDC, then this hydrogen will ignite. And as you rightly say, hydrogen burns much faster than diesel.
> 
> And indeed, in a Diesel engine the charge reaches a temperature of about 700 to 900 deg C at TDC, however mainly not due to residual heat as you said but due to compression]. It is now rather difficult to guess at which point the 560 deg C ignition temperature of hydrogen will be exceeded, but it will certainly happen significantly before TDC. It is a different story in a petrol engine, though._


To follow this line of though you have completely forgotten about combusted HHO forming water/steam, everything will now operate at a lower temp. I think you will find that the rapid rise in temp that creates combustion is a result of the fuel being injected at high pressure changing the density within the combustion chamber.



GBrapido said:


> ...production of NOX...





Boff said:


> _I have indeed ignored energy losses through NOX production so far, and for two reasons:
> 
> Firstly, because the amount of energy that is wasted here, and therefore the savings potential, is below 1% for any engine that fulfills current emission standards. NOX production is more a matter of pollution, than of efficiency._


I think here you have missed the tuning aspect of emission control, much power and fuel is wasted in an effort to reduce the amount of NOX created, EGR valves, reduced turbo pressure and controlled injection timing is all power sapping and therefore fuel inefficient and a waste of energy.



Boff said:


> _Secondly, the rate of NOX production is (exponentially) temperature-dependent (Arrhenius equation). So to reduce total NOX it would be better to keep combustion temperatures low as long as possible._


This is the effect of the water/steam added to the mix, water absorbs near 3 times the heat energy of air but it can only hold it while under extreme pressure

However,


GBrapido said:


> ...by increasing the speed of combustion in phase 2...





> ="Boff"_... the temperature level in the charge rises faster, and maybe to a higher level. So NOX production starts earlier, operates at a higher rate, and stops at the same time as before. *Ergo, more NOX will be produced.*_


I believe not as previously stated.



Boff said:


> _Now this might at least partially be compensated by the reduction of available nitrogen in the air intake. However, while adding a stoichiometric mixture of hydrogen and oxygen will certainly displace a part of the nitrogen, it will in proportion also displace a part of the oxygen. And as all the additional oxygen will be used up by the hydrogen, the total amount of oxygen available for fuel burning will be reduced. And how a reduction of available oxygen can lead to accelerated burn, that I still fail to understand..._


I believe you have already answered that your self in earlier posts, hydrogen is almost impossible to completely contain so a portion of it is lost through the inlet track before it reaches the cyl, what does arrive from the electrolyser into the cyl would be oxygen rich, not stoichiometric. By what amount there is probably no way of knowing.



Boff said:


> _The HHO mix will however, as Terry rightly says, end up in form of superheated steam. Now the specific heat capacity of steam is about twice as high as that of air, so the heat losses via the exhaust gases will increase, not decrease._


Again, I don't believe this is the case, water injection reduces exhaust temp, detonation in petrol engines and adds a measurable increase in power. If this was not the case it would never have been used on highly boosted race engines. Water it's self does not burn, therefore the increased power must have come from steam.



Teza37 said:


> But if we are talking about a reasonable sized M/Home then we already have the room to carry a few AGM batteries, solar panels and some where to fit a decent sized electrolyser. The energy to recharge these batteries can be from the solar panels, shore power when hooked up and regenerative braking when travelling.





Boff said:


> _Of course in theory this is possible. However, if you equip your van for regenerative braking, then you would need to retrofit a powerful electric generator anyway. (The standard alternator is far too weak for that, and it is separated from the wheels anyway as soon as you hit the clutch.)_


The intention is only to replace the energy used from the batteries during HHO production, as no fuel energy is used in over run or braking the remaining capacity within the existing alt. can be utilised. I don't know what sized alt. are used on European vehicle but 140amp + is common around these parts.



> ="Boff"_And if you had such a generator, you could also run it as an electric motor, directly from your battery._


Allison already have a bus transmission that does exactly that, but an internal combustion engine is still required to produce the initial and sustained motion.



Boff said:


> _So all the electrolysis stuff would be totally obsolete from the very beginning, a pure waste of energy. _


I have always considered turning potential energy into heat via the braking system to be a pure waste of energy, anything that could harvest some of this waste must be a good thing.



> ="Boff"_While in the engine, the temperature will be well above the dew point, so it will like all the other components of the charge just follow the adiabatic expansion curve. And it is of vital importance for both engine and exhaust system that it does just that and only condensates after having left the exhaust. If steam condensates within the engine or exhaust, then it will form a rather corrosive acid._


This quite correct, the exhaust temp would not drop below 100degC. Maybe my wording of returning to water could have been put better but that is what it is trying to do so it releases energy to achieve this state. It's not the fluffy white steam that comes from the kettle that drives a steam engine but that is the part that everyone sees.

Aussie Terry


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## motaman

*running on water*

bin using this for many years in four engines and it does work difference is each one of these engines knock out about 40,000 lbs of thrust and propel vehicles thro' the air, but the principles the same, injecting water vapour into a combustion engine. ask the jumbo jet makers . down side ow long u got? water vapour in oil etc


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## sallytrafic

*Re: running on water*



harley5321 said:


> bin using this for many years in four engines and it does work difference is each one of these engines knock out about 40,000 lbs of thrust and propel vehicles thro' the air, but the principles the same, injecting water vapour into a combustion engine. ask the jumbo jet makers . down side ow long u got? water vapour in oil etc


No Harley I think the principle is different. In a turbine surely its just increasing the mass of the charge.


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## motaman

*running on water*

yeah frank i'm sure its a bit of that as well ,its just that i've just got back from the pub the missus 'ent looking for an argument so i turned the computer on regards gary


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## Boff

Hi!



Teza37 said:


> To follow this line of though you have completely forgotten about combusted HHO forming water/steam, everything will now operate at a lower temp. I think you will find that the rapid rise in temp that creates combustion is a result of the fuel being injected at high pressure changing the density within the combustion chamber.


No I have not forgotten about that. However, in a Diesel engine the bulk of the temperature increase before ignition comes from compression. If you increase the total heat capacity of the charge, for instance by adding water, you will indeed have a slower increase. But then two questions occur:

1. The original claim of this thread was that by adding HHO the engine's efficiency could be increased. As we have already ruled out all other possibilities, the only plausible way of increasing efficiency would be to increase peak pressure in the engine during combustion. And peak pressure increase necessarily leads to peak temperature increase. Means more NOX.

2. If you are anyway only keen on adding _water_, then why not do just that, and avoid the extremely wasteful path via electrolysis.



Teza37 said:


> I think here you have missed the tuning aspect of emission control, much power and fuel is wasted in an effort to reduce the amount of NOX created, EGR valves, reduced turbo pressure and controlled injection timing is all power sapping and therefore fuel inefficient and a waste of energy.


No, I have not forgotten about that, either. Engine tuning, no matter how you do it, always means finding a compromise between max. efficiency, max. power, engine lifetime, and minimising emissions. Now I don't know how this is handled in Australia, but here in Europe emission regulations are rather strict. And are made even more strict every couple of years. Now if your vehicle exceeds certain emission levels, you face increased taxes, will be banned from certain areas, and at a certain point even loose roadworthiness.

So whatever you do regarding engine tuning, certain emission thresholds may not be exceeded. Which reduces the degrees of freedom a tuner has significantly. Now I don't know but I assume that ordinary passenger cars are tuned in the factory towards a compromise between power and efficiency, while the buyers of so-called "green" cars accept a reduction of peak power output in exchange for more efficiency. Sports-car buyers will probably see this just the other way round.

Of course, there are aftermarket tuners who do ignore the legal requirements. But then their tuning makes the roadworthiness certificate void.



Teza37 said:


> I believe you have already answered that your self in earlier posts, hydrogen is almost impossible to completely contain so a portion of it is lost through the inlet track before it reaches the cyl, what does arrive from the electrolyser into the cyl would be oxygen rich, not stoichiometric. By what amount there is probably no way of knowing.


This is true. And I have intentionally neglected hydrogen leaking so far. But even if we don't know it, let us just make a guess and see what comes out:

In a previous posting, I have taken my motorhome running at constant speed of 100 kph for one hour as an example. I had assumed that 1% volume of oxygen is added to the air intake. Which comes along with 2% volume hydrogen. I will assume now that half of the hydrogen leaks out, so we add 1% oxygen and 1% hydrogen. Now as half of the hydrogen has disappeared, only half of the additional oxygen will be consumed. So we add 0.5% oxygen, and at the same time we remove 0.42% due to air displacement. Which means that if half of the hydrogen leaks away, the total amount of oxygen available for fuel burning will increase by not more than 0.08%. Which is less than the normal fluctuations due to altitude, weather changes etc.



Teza37 said:


> Again, I don't believe this is the case, water injection reduces exhaust temp, detonation in petrol engines and adds a measurable increase in power. If this was not the case it would never have been used on highly boosted race engines. Water it's self does not burn, therefore the increased power must have come from steam.


Under certain conditions water injection can indeed increase the efficiency of an engine. However, firstly you are wrong in assuming this has anything to do with the steam. The reason why water injection can increase the efficiency is because it lowers the temperature, and therefore increases the density, of the charge *before combustion.* And the efficiency depends on the temperature difference before and at combustion, so instead of increasing the peak temperature at combustion you can also reduce the "start temperature".

And secondly, as said above: If you want to inject water, then do just that and do not waste lots of energy on converting this water into hydrogen and oxygen prior to injection.



Teza37 said:


> The intention is only to replace the energy used from the batteries during HHO production, as no fuel energy is used in over run or braking the remaining capacity within the existing alt. can be utilised. I don't know what sized alt. are used on European vehicle but 140amp + is common around these parts.


140amp at 12 volts results in 1.68kW, for any decent recuperation on a 3.5-tons-MH you would need at least 50 times more power. The alternator is just not fit for this job.



Teza37 said:


> Allison already have a bus transmission that does exactly that, but an internal combustion engine is still required to produce the initial and sustained motion.


As said, my normal car, a Toyota Prius, does that. It uses however not a standard alternator, but a 50kw motor/generator unit operating at 500 volts.



Teza37 said:


> Boff said:
> 
> 
> 
> _So all the electrolysis stuff would be totally obsolete from the very beginning, a pure waste of energy. _
> 
> 
> 
> I have always considered turning potential energy into heat via the braking system to be a pure waste of energy, anything that could harvest some of this waste must be a good thing.
Click to expand...

You are right. But if you harvest these wastes by recuperating, then you harvest electrical energy. Which you store in a battery. And converting this energy back into mechanical energy via an electric motor is about 90% efficient. While converting it back via electrolysis and combustion would result in not more than 15% efficiency. Hydrogen leakage not considered. So again, why take a detour that cuts your efficiency to one quarter of what you could achieve?

Best Regards,
Gerhard


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