Water injection and alcohol fuel 14

[patprimmer]

azmio

If the water enters the chamber in liquid phase and exits the exhaust in gas phase, surely some energy is lost out the exhaust in the form of latent heat of vaporisation.

Regards
Pat
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[azmios]

pat, i see it differently. The reward in gas expansion is the reward to a small price that we have to pay in the form of latent heat of evaporation. After all, the process is reversible. You cant do the same with combustion process, once it happens, it is not reversible.

 

[patprimmer]

So what. The latent heat of vaporisation which is significant just gets blown out the exhaust. If it is then reversed by giving heat to the surrounding air. That has no influence on what happens in the chamber.

Regards
Pat
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[azmios]

not really, even when the steam is blown out through the exhaust gas, it can be recovered through a condenser and there is significant amount of thermal energy that can be recovered and reintroduced into the combustion chamber.

 

[patprimmer]

slim

Did you have a condenser and recirculate the energy recovered from the exhaust.

Azmio

I am interested to know just how you get this energy back into the Otto cycle 4 stroke automotive engine which is the engine type in question.

Regards
Pat
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[140Airpower]

azmios, You complain that no one has tried "this" and there isn't any information on "that", but in reality, people have tried virtually everything we are talking about and there are tons of information about what they have found. You have to do the research. You need to see it for yourself because you are not accepting what is being said here.
There are contradictions in things you have proposed. For example, you thought a benefit of injecting water was as a coolant, now you want to preheat the water. The idea of using pure oxygen was to get a more intense burn, but a consequence of a hotter, faster burn is a very significant reduction in the effective octane number of the fuel mixture. This is anathema for a spark ignition engine. You propose having a cumbersome, power hungry oxygen generator and a steam condenser for an automotive application where these things are handicaps. Your ideas are all over the map and don't make good sense.

 

[thruthefence]

A perfect "Steampunk" construct, possibly powering a wrought iron dirigible!

 

[azmios]

pat, if you inject water in the combustion chamber at 50C compared to 25C. It will take lesser heat to get another 50C and turn it into steam to make work. Theoretically any secondary heat source that can be used to increase the water temperature is now valuable.

 

[azmios]

Air, why does it have to be related to me and my flaw in character? Cant we just stick to the points in this debate?

While many have tried injecting methanol+air in real life, has anyone came up with convincing scientific reasoning to answer the questions that myself and Slim3 are asking? I never said that no work or researches have been done, it is just the scientific reasoning that is lacking and this is what I am seeking at this moment.

By the way, I am now proposing things all over the map. I am just highlighting what have been discussed by the author in the SAE paper 2009-01-2808. Have you read it and fully understood all the points?

 

[Tmoose]

SAE paper 2009-01-2808. by Azmi Osman

http://ergosphere.files.wordpress.com/2011/01/2009-01-28081.pdf

http://en.wikipedia.org/wiki/Petronas

 

[Slim3]

Pat & Azmios,
I did not have a condenser on either the alcohol engine nor on the two Dodge 318 engines. But the thought did cross my mind and on a third engine that only made it on the drawing board I did consider it. I wanted to build a small SI engine the run two cylinders on gasoline slightly richer then stoichiometric and put a heat exchanger with internal spray nozzles using water to make steam and storing the steam for a small on board two stage piston engine to add what power could be obtained via a simplex drive system. Then at the heat exchanger add whatever flame trap I could design to be sure to put the fire out in the exhaust of the two gasoline cylinders which should produce a hot but no fire exhaust gas that is very dirty with a lot of HC. I then intended to inject ethanol alcohol into the exhaust gas to further cool and contract the exhaust gas which would be routed to another cylinder in an attempt to get a second combustion. Then have my heat exchanger on that exhaust port also to attempt to gain more steam for the small on-board steam engine. The end result would be a small four cylinder engine with two cylinders on gasoline and two on dirty exhaust of the first two with alcohol added to bring that exhaust up to a combustible mixture and all four having a heat exchanger producing steam for a small two stage steam engine adding power to the small 4 cylinder engine. The balance of all of this would get upset as soon as I moved the throttle so I would use it as a single speed set at wide open throttle to power a generator to keep a battery pack charged for a electric car. A friend was in on the designing and I tried to show this to Nissan in 1979 but they didn't want to look at it. I got the same response from GM and even Jack Roush. However, in doing the research on alcohol for the project (we both knew a little about alcohol as a racing fuel) I accidentally received a grant form the DOE to build a still and modify an engine to run on straight ethanol. So I got side tracked into an alcohol engine sponsored by the US DOE and that netted me the alcohol/water injection systems which I put to use on two dodge trucks. Briggs and Stratton also sent me a small gasoline engine to play with which I set up as a small dyno with EGT and head temp and dual fuel to measure different mixtures of both fuels, alcohols and gasoline. So here I am still looking for answers. Some of this research lead me to think of direct injected compressed air to start an engine which I did complete and just entered the car in an show this last Saturday. (Olds 215 engine in an MG) Got 3rd place in class probably because of the unique direct injected compressed air start system.
Slim3

 

[Lou Scannon]

The figure above is from NACA research memorandum E6106, which investigated methods of reducing peak cylinder head temperature in cylinder 10 of a Wright R-2800-21, which would otherwise exceed the manufacturer's specified limit at military power, as installed in a P-47G aircraft. One of the methods investigated was injecting water/ethanol into the intake pipe of cylinder 10. At the top of the figure, the effect of coolant injection rate (on the x-axis) on net BHP is shown. The BHP indicated is for the entire engine, so the changes in power are due to changes in cylinder 10 only, as operating conditions for the other cylinder were held constant. It can be seen that as coolant injection rate increased from 0 to 40lb/hr, cylinder 10 power decreased 30BHP. Assuming cylinder 10 was contributing an equal share of net power with zero coolant injection, this is a reduction of about 35%.

"Schiefgehen will, was schiefgehen kann" - das Murphygesetz

 

[Lou Scannon]

Pat wrote:
"I don't have the data at hand, but I remember reading somewhere, probably in an NACA report that water is one of the few liquids where when it evaporates into air, the gas produced does not fully compensate for the loss in volume of the air in the system due to the heat absorbed."

How about this one:

NACA Report 756 Figure 6

Effective charge air density is shown at the top of the figure, for different [injected] water-to-fuel ratios, and as a function of fuel/air ratio. If the image quality raises ambiguity about the symbols, the air density shows a monotonic increase with increased water-to-fuel ratio.
The curves for IMEP at the bottom of the figure are interesting also. While the effect of water injection between 0.06 and 0.09 fuel/air ratio doesn't appear to be significant, the data above 0.10 fuel/air ratio clearly show a monotonic decrease in IMEP with increasing water-to-fuel ratio.

"Schiefgehen will, was schiefgehen kann" - das Murphygesetz

 

[patprimmer]

azmio

If you cannot see the inconsistencies and lack of fact in your arguments then either you are not an engineer or you have some other problem.

Every single real working engineer here most with professional qualifications disagrees with you. Do you wonder why.

slim.

I knew you did not have a condenser as it was an idiotic suggestion and you are obviously far from idiotic. Your only limitation in this debate is a lack of education which you came here to rectify.

Unfortunately you thread has been hijacked by someone who is on a major misinformation propagating campaign for whatever reason. I could only speculate that reason. A few possibilities are:-

1) He has been misinformed by a source he trusts with a religious fervor.
2) He is a troll.
3) He has some commercial interest in a snake oil device.
4) He has discovered the laws of thermodynamics as accepted now for maybe 100 years are in fact severely flawed (I can't really be bothered looking it up just to help disprove obvious BS).
5) He is from the tin foil hat brigade.

I guess this post might get deleted and I may be reprimanded as I have probably been to honest.

Hopefully we can get back to real science and fact.

As I said earlier I believe that your power increases come from the much more effective charge cooling you get from water over alcohol and that evaporating water, in the manifold only, increases charge density whereas evaporating alcohol in the manifold decreases charge density.

I am pressed for time so I have not read the latest links, but I think the NACA reports will support this.

The NACA was the precursor to NASA and goes back to the Wright Bros and was the research body that lead the way into aircraft performance gains during WW11. In my opinion they are extremely credible. If not, the P51 might have been a dud.

Wikipedia is at times flawed, but it will give a reasonable basis.

http://en.wikipedia.org/wiki/Laws_of_thermodynamics

This is also flawed. For example they use the term heat where they at times should use the term energy but what the heck. They do a very good job of presenting it in simple laymans terms.

http://www.ridgenet.net/~do_while/sage/v7i1f.htm

Regards
Pat
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[Lou Scannon]

All,
Let me know if the graphics that I inserted in my above 2 posts do not show up. In that case, I will provide direct links to the documents. From there, you will have to load the documents, and navigate to the figures in question.

"Schiefgehen will, was schiefgehen kann" - das Murphygesetz

 

[Slim3]

Hemi, The wright engine lost 30 brake horse power power on one cylinder by injection of water/alcohol and that resulted in a loss of 35% of the power that #10 cylinder normally produced? Is that true?

Do you have any info on what the water/alcohol ratio was (proof)? also what volume of alcohol was injected?

I used a 50/50 mix (100 proof ethanol) on the two Dodge engines. I had no method to measure air/fuel ratio. These were both carburetor engines and I fed the Alcohol/water in via a vacuum hose with the throttle at full throttle at a volume that caused the engine to stumble then I leaned out the alcohol with a manual metering valve until the engine cleared up. The system used a sealed glass bottle with the air supply to a tube to the bottom of the bottle so as I adjusted the supply to the engine I could see the volume of air entering the bottle. This didn't give me any figure of how much alcohol was being consumed. I guess I could have done it roughly by measuring how much alcohol was consumed in one 1/4 mile acceleration run and measured how much gasoline was consumed to come to a figure of what the gasoline/alcohol ratio was. At the time I didn't care and was only confirming what the company who gave me several units to test and play with. The only thing at the time that I was trying to confirm or dispute was the Proof of alcohol as they claimed 100 proof worked best. So I tested the one truck on no injection, and almost a dozen different ratio water/alcohol from plain water on up to 200 proof alcohol.
their claim of 100 proof proved to be correct.

The only thing I do know is that the power results were dramatic enough to show on a stop watch. And it did the same on two different trucks.

So I know something was drastically different in the procedure used in that Wright engine tests.

In other tests I ran on another engine I did get about a 35% loss of power in a low compression engine when I switched from gasoline to alcohol and I contributed that to the less BTU value of alcohol verses gasoline. I then raised the compression ratio far past what gasoline can even operate at and gained more power then the engine originally had and could have on gasoline.

Slim3

 

[Lou Scannon]

Slim3, the point is this. We all know alcohol as a fuel can make more power than normal gasoline, if the engine is setup and calibrated to take advantage of alcohol's combustion properties. However, my post on the R-2800 #10 cylinder investigation was aimed at the question of what is the effect on power adding water or water/alcohol as a supplement (e.g. for internal cooling) to an engine running as intended on gasoline, with no other changes.

In answer to your specific questions about the investigation, your first statement is correct. The ratio of ethanol to water used was 50% by volume. The mass flow of coolant injected is given on the x-axis of the figure I inserted. If you can't see the figure, you can download the complete report here.

"Schiefgehen will, was schiefgehen kann" - das Murphygesetz

 

[Lou Scannon]

Slim3, I have to address a statement you made earlier. Please take this in the fully constructive spirit that is intended.

I noted that in the mid 70's on, when emission control was applied to auto engines, the combustion chamber temperatures climbed higher (thus burning the Nitrogen and producing NOx). However, with the increase in combustion chamber temperature came much lower horse power.

In fact, as soon as NOx became a regulated pollutant, efforts at reducing NOx formation during combustion have focussed strongly on limiting peak temperatures, and did succeed dramatically at both limiting peak temperature and NOx formation rate. This same strategy is at the core of NOx emission control to the present day.
Limiting peak temperature has been done many ways. In the 70s, the tools available were limited and somewhat crude. They were: reduced compression ratio, retarded spark timing, and, at part load, EGR (I believe this was done internally, via valve timing, as well as externally, on various applications). You don't need me to tell you that each of these strategies has the inherent side effect of reducing power.
By the way, a second side effect, that goes hand in hand with reduced power, is increased exhaust temperature. The heat energy that is not converted to pressure pushing down the piston, goes out with the spent charge. From the perspective of emission reduction, this is seen as a good thing, as the increase in exhaust temperature provides an environment in which unburned hydrocarbons can continue to react with available oxygen, resulting in less engine-out HC. Of course higher engine-out exhaust temperatures are typically beneficial to exhaust catalyst operation as well.
A secondary side effect of these peak temperature reduction strategies can be increased heat rejection to the coolant. Some of this increased heat may come from heat transfer from the exhaust ports to the coolant. And some comes from the fact that, for the same vehicle mission, more fuel has be be burned, so the heat rejection to the coolant is increased in proportion to the reduction in thermal efficiency.

"Schiefgehen will, was schiefgehen kann" - das Murphygesetz

 

[Slim3]

Hemi, My tests of the two Dodge 318 trucks was done with the engines on gasoline and no alterations at all were made in timing nor fuel mixture. So nothing was changed except the addition of a small volume of 100 proof alcohol to the intake. I first thought it could be the addition of a small amount of fuel as I knew you can gain hp by a richer mixture, but I felt that the small volume of alcohol that was used didn't account for the power received. So trying to think further I thought possibly the evaporation of the alcohol in the intake caused a more dense air charge thus more of everything in. All of this was in the early 8's.

In the late 60's I was an MG, Triumph, Jaguar, Lotus mechanic and we did see lower compression, EGR and leaner mixtures as the main cause of the loss of power. Most of our customers were young and didn't like getting out run from a light by a 53 Buick with an automatic transmission so they came in with tears in their eyes but we being a dealership, could not alter the cars in any way. In 1968 I out ran a mechanic in a new 1968 Jaguar "E"type 4.2 (which in 67 was a 150 MPH car) and I did it with a 66 MGB (1800cc push rod Austin tractor engine) and I did it in every way he want to run, acceleration or top end.
Slim3

 

[140Airpower]

Hemi, that is a good an accounting as I've heard of the miseries of the '70s. The industry did a lot of work to get us from there to here. The remarkable advance is all the more impressive when you consider that the auto engine was not a new, undeveloped technology. What was new, however, was the application of computers to every phase of development, design and production and operation and the innovation of computer controllable engine parameters.