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You are correct, in a gasoline engine running at maximum efficiency about 70% of the energy available from the gasoline is lost as heat in the exhaust and cooling water. This is a fact of thermodynamics and you are not going to improve on that.Originally Posted by Khalid
You are also correct that some of the gasoline is unburnt; this used to be a significant amount with carburetted engines but with modern fuel injection and oxygen sensors it is dramatically reduced.
It is possible that introducing a small amount of hydrogen into the gasoline/ air mixture could improve the efficiency of combustion; I have never seen anything about controlled studies done to measure this but it cannot be ruled out. However, this improved efficiency is only going to more completely burn the gasoline, so the overall improvement cannot be greater than the percentage of unburnt gasoline in a normal engine. What I mean is that if 5% of the gasoline is unburnt (and I have no idea how correct this is; I think it is probably high) then totally burning the gasoline gives a maximum improvement of approximately 5%., and from this you have to deduct energy losses involved in hydrolysing the water to get the hydrogen in the first place. Improving gasoline mileage by 20% or more with this conversion is not possible.
You are confusing POWER and WORK:
WORK is when a force acts through a distance; i.e. lift 550lb through a distance of 10feet and you have done 5500ftlbs of work.
POWER is the rate of doing work; how fast do you move the force through the distance. Lift 550 lb through a distance of 10 feet in 1 second and you are using 10 hp.
When you use a lever, chain block, hydraulic jack, or any other device which gives you a mechanical advantage you will do the same work. The difference is you have reduced the force but increased the distance over which it acts; because this will take longer you need less power.
This comment is from a parable, or fable, I think but my memory fails me. What is the complete saying?...So don't be a frog of a well.. comes outside the well and see the universe...
An open mind is a virtue...so long as all the common sense has not leaked out.
hehehe..thanks Geof...OOOpppss really i am wrong on power and work..its the basics of engineering...sorry for making confusion here..thanks for correction..
I really don't know about the that fable in English language, but in my national language i have heared a nice story of that frog
I was going to say the English fable was probably plagiarised from your country two or three centuries ago, but then I did a Google search; 'fable frog in well'. It is a Chinese fable so I guess we both stole it....I really don't know about the that fable in English language, but in my national language i have heared a nice story of that frog
An open mind is a virtue...so long as all the common sense has not leaked out.
Hahahaha....... I am smaller theif bcas China is in my neighbour and the distance from china is much larger from ur country so u are big theif..i can say u are my boss
The whole point of the exercise should indicate that the law of "diminishing returns" is alive and kicking in the case of making Hydrogen (and Oxygen) from water using the additional energy obtained from the petrol.
It takes a whole lot more energy to produce the Hydrogen and Oxygen by hydrolysis, than you'd get if you just used that energy (petrol) to drive the car without putting a load on the alternator to supply the current to break the molecular barrier of the water and getting less back for your money.
Otherwise it would seem the people who advocate the water "economiser" could just as well advocate converting the car totally to electric/battery power obtained from the mains, to hydrolyse the water and so run the engine on Hydrogen/Oxygen as a result.
It might be very Green and clean, but the extra power for charging the batteries isn't.
While it would definately work after a fashion, what wouldn't work would be the comparison to your electricity bill before and after charging the battery to produce the Hydo/Oxy mix, and then compare the distance travelled and cost when you would have used petrol.
The simplest way is the best, when all things are equal, and spraying fuel into a volume of air and using the mixture to drive a piston down a cylinder bore is the most direct way to get the wheels moving, anything else added to the process is absortion of the energy available.
Thinking outside of the box can lead to the weird and wonderfull world of the imaginative dreamer, when all it takes is applied mechanics and the law of physics to achieve the object of the exercise.
To cite a typical case in mind, the inventor of the Orbital engine, some years back, burst onto the scene with a fantastic fanfare of braying trumpets, hailed by the press and many politicians of the day as the major breakthough of the century in engine innovation and design.
Where is it now? I hear that all development has been abandoned due to the impractical mechanics and dubious results of performance.
At this moment in time, the major form of automative power is the 4 stroke cycle, with a smaller proportion of the power producers going to the 2 stroke principle, but the 4 stroke cycle only gives at best 30% of the fuel's energy, the rest , 70%, goes in engine management, without which the engine could not even yield up that 30%.
The moral of the story is, keep it simple, make it work, and anyone who has turned the key and failed to hear the engine fire knows what it means to keeping it simple once you lift the bonnet and survey the latest technological breakthrough, be it going Greener or trying to wrest that last ounce of torque.
Some people have thought so far out of the box they've forgotten what the original concept was for.
Ian.
You say engine management takes 70% of the fuel's energy - is that a tax of some sort? What percentage does the speed governor get?
Red to red and black to black, or it's ashes to ashes and dust to dust.
After combining mechanical efficiency and thermal efficiency, the typical engine is about 20-25% efficient. The remainder of the efficiency is paid not directly, but as a tax. Remember, we're talking about Laws of Physics, and Laws require overhead and management. Once a law is passed, it must be administered.
In handlewanker's case, the difference between the reality efficiency and his 30% claim is evidence he's skimming off the top, or more likely, he's running a Madoff-modeled Ponzi scheme on the excess 5%.
"Braying trumpets"??? Chris Botti would love that one.
Yeah, OK, whatever Fizzwizz, about 30% on a good day, but I expect ya' don't have yo' gas guzzler seviced that often to keep it in tune, that's a fool's paradise, save on the servicing and pay on the petrol, wot' yo' got boy, shares in the petroleum industry?
So we'll assume yo' get 20% to 25% on any day.....the engine management I mentioned accounts for shoving the piston up the bore to expell the burnt gas and then dragging it back down again to get a fresh bit of petrol air mix on board, and then again pushing the piston up as far as it will go to compress the stuff and,...... wait for it,..... the grand finale,..... the big bang, which is the only bit the engine gets out of the deal to accomplish the above mentioned functions, not a lot to write home about.
In addition to the wasted part of the big bang function, the petrol air mix doesn't get fully burnt, so some of it goes out with the bath water so to say, and that is probably the bit 'ol Fizzwizz got excited about, that 5% part, always the one to be a nit picker...LOL.
Incidently, no matter how it's been wangled, ain't nobody been able to devise a better way to push a load of meat,metal, upholstery and rubber along a patch of tarred stonework than by occasionally exploding a petrol/air mix in a metal box once for every two revolutions of a twisted iron rod, .....nobody.
One could of coarse take one's thinking cap out of the box and put it on to consider the aspect of 'shoes and ships and sealing wax, and cabbages and kings, and why the sea is boiling hot and whether pigs have wings', etc etc, but it won't improve the economy of the 4 stroke cycle no matter how much water you add to it.
Incidently, what fool said that adding water to the petrol mix would increase the power of the petrol by making the air/petrol mix denser when it combusted, so turning the water to steam and thereby exerting a greater pressure on the piston crown?
In order to make steam yo' gotta use some of the energy of the petrol to make it so, and that don't leave much for the expansion of the air that actually does that job.
It takes more petrol energy to bring the water to the boil and get steam, even if you burn it outside the engine and pipe it in through a valve at the right moment, commonly called a steam engine......oh yeah, they went out last century....wonder why....and if'n yo' connected the steam engine up to a generator and made electricity to charge a battery that turned an electric motor to drive the car, you'd have to have your own private oil well and refinery just to make it work, 'cos the efficiency at the end point would'nt even be worth measuring.
Ian.
Water injection has its place to improve efficiency as an octane booster rather than as a fuel. From the PM site above, comment #165 explains it well:
"As a general rule, the fuel mixture is set at full rich on an aircraft engine when running it at a high power settings (such as during takeoff). The extra fuel does not burn; its only purpose is to evaporate to absorb heat. This uses up more fuel, and it also decreases the efficiency of the combustion process.
By using water injection, the cooling effect of the water allows the fuel mixture to be run leaner at its best-power setting. Due to the cooling effect of the water, aircraft engines can run at much higher manifold pressures without detonating, creating more power. This is the primary advantage of a water injection system when used on an aircraft engine. "
Red to red and black to black, or it's ashes to ashes and dust to dust.
heh heh heh, this old hoary chestnut....
my twenty cents worth...
monatomic hydrogen. sounds fancy, dont it? simply H...not H2. what we call hydrogen is H2. it takes some energy to break this bond. then the H can combine with O, that also required energy to be broken from O2.
its strange that in chemistry, its well known that "naescent hydrogen" is more volatile than old stuff thats been in that bottle for 6 months. why? "naescent" means "new". freshly made hydrogen contains a larger proportion of free H atoms. the physicists dont like communicating with other branches of science and ignore this...
so we had things such as "monatomic hydrogen welding", blowing a stream of hydrogen gas through an arc held between two electrodes. somehow managed to transfer the energy of the arc through the hydrogen.
then theres the HHO and browns gas welders... HHO...two monatomic hydrogen atoms and one monatomic oxygen combined...that require literally no energy to initiate combustion...
so where was i?
oh. i believe a lot of failures is also caused by trying to produce enough gas from electrolysis to meet the engines requirements... not considering stoichometry.
the air we breathe, and the engine, only contains approx 20% oxygen.
so we only have to produce hydrogen, in enough quantity to achieve 2:1 H2:O2. yes, still quite a lot. 40% of the engines intake roughly.
anyways. get a 2 volt lead acid battery. go and stick your car battery onto it, 12 volts.
now tell me its not producing gas... a fair bit of it too. hydrogen
yes, so you destroyed the battery. so make one thats intended to be used like that from stainless.
the gas seems to be formed from edges, scratches, imperfections... so use perforated mesh?
and lastly... hydrogen upon combustion at atmospheric pressure, contracts. violently.
not explode. implode. so.... set your ignition to fire at BDC... use a very lightweight oil... contraction equals cooling...
Sounds logical?..... you mean firing at BDC you get a vacuum engine, which at the best of time is very weak, and using the car battery to produce the H also makes it implausible if not impractical, but in any event impossible.
The con man who proposed the article and who sold the "kit" and also plans to make the thing on Ebay, stated categorically that it "improved" the fuel consumption of a petrol engine, which it can not do, no matter how the figures are "rearranged", either chemically or electrically.
Ian.
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