HHO Fuel Cells
Discussion
R300will said:
Super Slo Mo said:
Max_Torque said:
Nice one!
Pity it's not actually true......................
(Hint, where does the energy (heat) to vapourise (and state change) the water come from? Yup, thats right, it comes from the combustion event itself. If we assume an adiabatic process (reasonable given the short time period) the total energy exchange is zero. Steam is produced, heat is reduced, so energy is the same)
It reality, just injecting water will directly lead to a reduction in total combustion energy (because it displaces some intake charge volume, and tends to increase the heat rejection (lower thermal co-efficient) to the chamber walls. However, on a high boost forced induction engine, where the spark sensitivity is such that the cooler charge allows enough spark advance to be added, more power can be released (effectively a larger proportion is transmitted as useful work to the piston rather than lost as heat to the exhaust).
Bugger!Pity it's not actually true......................
(Hint, where does the energy (heat) to vapourise (and state change) the water come from? Yup, thats right, it comes from the combustion event itself. If we assume an adiabatic process (reasonable given the short time period) the total energy exchange is zero. Steam is produced, heat is reduced, so energy is the same)
It reality, just injecting water will directly lead to a reduction in total combustion energy (because it displaces some intake charge volume, and tends to increase the heat rejection (lower thermal co-efficient) to the chamber walls. However, on a high boost forced induction engine, where the spark sensitivity is such that the cooler charge allows enough spark advance to be added, more power can be released (effectively a larger proportion is transmitted as useful work to the piston rather than lost as heat to the exhaust).
My A-Level physics teacher told me about the expansion bit, and went on to make the above assertion.
Shame I never bothered to think a bit harder about it, and having gone all the way to get a Mechanical Engineering Degree, that's a little embarrassing.
http://en.wikipedia.org/wiki/Six-stroke_engine
I used to have water injection on my MR2 Turbo.
Used to use a water/methanol (wind screen washer fluid) mix and spray in between the turbo and intercooler. Kept the engine cooler (I ran with a load of monitoring gear for a guy who was making intercoolers), kept any oil out the IC and had a weird effect that whatever colour the water was, the flames would get tinted that colour (tried blue, green and pink).
My FIL is also trialing a HHO system on his Jag. It is appearing to work (it seems very sensitive to temperature though). But I can't see why it works. The only thing I can think of is it's fooling the sensors somehow and running lean (like the old 5p resistor in the air flow meter trick).
Edited by Bibbs on Tuesday 8th May 01:29
hairykrishna said:
Website said:
Q.THIS BREAKS THE LAWS OF THERMODYNAMICS AND THEREFORE SHOULD NOT WORK?
A. A common fallacy is that it takes more energy to produce the HHO than the energy it releases. This is not true.
All the electricity coming from your car’s alternator is in fact, free energy. Much of it is unutilised. Now since you are taking free energy from your alternator, to produce HHO gas from water, and pump that HHO gas back into your air intake, you are getting free energy, from free energy. Even if it is only 50% efficient , it does not matter, because there was no extra power needed from the normal processes that operate the car, to obtain the HHO.
Physics fail. Electrolysis takes more energy than is available from burning the hydrogen released. This is a fact regardless of how clever you try to be, otherwise you could connect the output to the input and have a perpetual motion machine of the first kind. Energy from from an alternator is not free. As the alternator load goes up so does the power required to run the alternator. Again this is basic thermodynamics - it has to work like this otherwise you could connect the output to an electric motor to run the alternator and you'd have a perpetual motion machine again.A. A common fallacy is that it takes more energy to produce the HHO than the energy it releases. This is not true.
All the electricity coming from your car’s alternator is in fact, free energy. Much of it is unutilised. Now since you are taking free energy from your alternator, to produce HHO gas from water, and pump that HHO gas back into your air intake, you are getting free energy, from free energy. Even if it is only 50% efficient , it does not matter, because there was no extra power needed from the normal processes that operate the car, to obtain the HHO.
There has been real research into hydrogen injection to allow much leaner mixtures to be used, which works well in some applications. It's not as straightforward as plumbing a dinky little electrolysis cell into the intake though.
Its only free as long as you ignore the big petrol motor turning it
. The more power being drawn buy the alternator, the harder the motor has to work.98elise said:
hairykrishna said:
Website said:
Q.THIS BREAKS THE LAWS OF THERMODYNAMICS AND THEREFORE SHOULD NOT WORK?
A. A common fallacy is that it takes more energy to produce the HHO than the energy it releases. This is not true.
All the electricity coming from your car’s alternator is in fact, free energy. Much of it is unutilised. Now since you are taking free energy from your alternator, to produce HHO gas from water, and pump that HHO gas back into your air intake, you are getting free energy, from free energy. Even if it is only 50% efficient , it does not matter, because there was no extra power needed from the normal processes that operate the car, to obtain the HHO.
Physics fail. Electrolysis takes more energy than is available from burning the hydrogen released. This is a fact regardless of how clever you try to be, otherwise you could connect the output to the input and have a perpetual motion machine of the first kind. Energy from from an alternator is not free. As the alternator load goes up so does the power required to run the alternator. Again this is basic thermodynamics - it has to work like this otherwise you could connect the output to an electric motor to run the alternator and you'd have a perpetual motion machine again.A. A common fallacy is that it takes more energy to produce the HHO than the energy it releases. This is not true.
All the electricity coming from your car’s alternator is in fact, free energy. Much of it is unutilised. Now since you are taking free energy from your alternator, to produce HHO gas from water, and pump that HHO gas back into your air intake, you are getting free energy, from free energy. Even if it is only 50% efficient , it does not matter, because there was no extra power needed from the normal processes that operate the car, to obtain the HHO.
There has been real research into hydrogen injection to allow much leaner mixtures to be used, which works well in some applications. It's not as straightforward as plumbing a dinky little electrolysis cell into the intake though.
Its only free as long as you ignore the big petrol motor turning it
. The more power being drawn buy the alternator, the harder the motor has to work.Use Psychology said:
could be interesting to use some kind of KERS to power electrolysis to make H2 and O2 to burn, don't expect you'd get much power from it though.
The amount of power needed to split water into seperate hydrogen and oxygen though electrolysis is massive. Certainly more than you would gain from it. On top of that the website is awful, certainly done by someone with very little imagination...Use Psychology said:
I know all that, but KERS for electrolysis might compete for efficiency with KERS for battery charging and then running an electric motor. as others have said, you get a bit more back because the H2 and O2 help you burn the petrol better.
When you say "might" what you really mean is "not even get close" To date, no scientific study has been presented to show the benefits (real or immagined) from ultra low volumes of hydrogen being burnt with normal fuel and air mass (remember, there is already 21% oxygen in the air your engine ingests!)I have worked for the best part of 20 years now in automotive development, and i can coun't something like 10 occasions where we have been given small pieces of test work to run these "crazy" ideas over a proper, EU homologated, vehicle drive cycle. So far, not one has actually produced a measurable benefit, and several have done exactly the opposite!
We have even been accused to "deliberately falsifying" the results by some dissapointed clients, even though we have exactly nothing to loose/gain either way (except our excellent reputation for accuracy and profesionalism!)
The simple fact of the matter is that if a simple, cheap and practicable (important that last one!) technology existed to significantly increase an IC's fuel efficiency, the OE's would already be using it (like EPAS, Stop start, multiratio DSG, direct injection, variable cam timing, knock control, inteligent warm up, EGR, turbocharging, downsizing and downspeeding, and about a hundred other good ideas.
The tinfoil hatters can say "oh but the oil companies hid the idea" as much as they like, but do you think that if you approached say the technical head of Audi and offered him a real 25% fuel economy benefit over say BMW, he would turn you down?????
To have a car tested over an NEDC cycle will cost you about £1800 (3 tests A-B-A), yet none of these people offering these so called "amazing fuel saving devices" can stump up the frankly small sum of one and a bit grand to actually prove their devices work?
And of course there is a very good reason they don't want to have their devices properly tested..........
Use Psychology said:
as others have said, you get a bit more back because the H2 and O2 help you burn the petrol better.
That's one of those statements that sounds perfect - until you stand back and ask 'Why? How?'. We know hydrogen and oxygen are very flammable so people assume they must make petrol 'burn better'. 'Well of course they will, they're flammable - look at the Hindenburg'.
But it doesn't mean they will. Max Torque has the definitive answer. Although I suspect the head of Audi would take the idea, say 'No thanks' then develop it himself
if you added H2 and O2 to your combustion charge you could burn more fuel per cycle though...
(adding O2 is the same as turbocharging basically)
Ok Max torque, interesting post, thanks. I was speculating in the abscence of knowledge, good to know people have tried it.
what if you lugged around a cylinder of H2 and/or O2 and mixed them with fuel, surely you would get more energy (like I said, adding O2 is the same as turbocharging).
(adding O2 is the same as turbocharging basically)
Ok Max torque, interesting post, thanks. I was speculating in the abscence of knowledge, good to know people have tried it.
what if you lugged around a cylinder of H2 and/or O2 and mixed them with fuel, surely you would get more energy (like I said, adding O2 is the same as turbocharging).
Use Psychology said:
if you added H2 and O2 to your combustion charge you could burn more fuel per cycle though...
(adding O2 is the same as turbocharging basically)
Ok Max torque, interesting post, thanks. I was speculating in the abscence of knowledge, good to know people have tried it.
what if you lugged around a cylinder of H2 and/or O2 and mixed them with fuel, surely you would get more energy (like I said, adding O2 is the same as turbocharging).
This may be wrong as i'm just thinking off the top of my head. But won't the air or, more importantly, oxygen concentration in the cylinder be at an excess relative to the petrol anyway to ensure a god burn?. So adding some more O2 wouldn't really do much? (adding O2 is the same as turbocharging basically)
Ok Max torque, interesting post, thanks. I was speculating in the abscence of knowledge, good to know people have tried it.
what if you lugged around a cylinder of H2 and/or O2 and mixed them with fuel, surely you would get more energy (like I said, adding O2 is the same as turbocharging).
Use Psychology said:
if you added H2 and O2 to your combustion charge you could burn more fuel per cycle though...
(adding O2 is the same as turbocharging basically)
Ok Max torque, interesting post, thanks. I was speculating in the abscence of knowledge, good to know people have tried it.
what if you lugged around a cylinder of H2 and/or O2 and mixed them with fuel, surely you would get more energy (like I said, adding O2 is the same as turbocharging).
"Burning" is actually oxidisation. You take an hydrocarbon fuel, and oxidise it, which releases heat energy and funnily enough carbon and oxygen as a byproduct.(adding O2 is the same as turbocharging basically)
Ok Max torque, interesting post, thanks. I was speculating in the abscence of knowledge, good to know people have tried it.
what if you lugged around a cylinder of H2 and/or O2 and mixed them with fuel, surely you would get more energy (like I said, adding O2 is the same as turbocharging).
This is a fixed chemical reaction (which is why fully oxidising (burning) a fixed mass of a hydrocarbon fuel produces a fixed mass of Co2)
You car is fortunate enough that the environment that it operates in already contains 66% of the fuel with which it operates, and you actually only need to add the other 33% (by mass) directly into the fuel tank!
However, hydrocarbon fuels have different specific energies and different desities (i.e. as they oxidise they release differing amounts of heat energy. Hydrogen has a higher specific energy (energy per unit mass) than gasoline, but unfortunately, its low density (even in liquid form) result in a lower volumetric energy density. So, if you displace a volume of your injected gasoline with the same volume of injected hydrogen (in liquid form) then your engine will actually make less power!
The poorly understood conter argument for HHO systems is that somehow the tiny volumes of hydrogen somehow make the gasoline combust "better". Well, considering that a modern ICE burns something like 99.9% of the fuel injected into it, with 0.1% just being ejected out the exhaust as unburnt vapourised hydrocarbons, i don't think that somehow suddenly burning that extra 0.1% is going to do much. The other augument is that it makes the fuel burn "faster". Now this could be a possibility, but unless you re-optimise your ignition angle to take account for this earlier heat release then that heat will just go out the exhaust rather than be utilised as extra work on the piston. So how many HHO systems also re-map your engine ??
The biggest issue is simply one of the tiny percentage of HHO produced. A 2.0 litre engine running at say 4000rpm at wide open throttle will suck in 67 liters of air every second ! Which therefore is 14 litres of oxygen per second. You puny little electrolysis cell is not going to be able to augment that very much without consuming massive power ( i'll leave it up to you to calculate exactly how much HHO you could sensible create with an automotive alternator (itself only 65% efficienct))
Use Psychology said:
what if you lugged around a cylinder of H2 and/or O2 and mixed them with fuel, surely you would get more energy (like I said, adding O2 is the same as turbocharging).
Yes, but you're introducing extra energy from outside, which is a different thing. The gases have already been made by an additional energy source outside the car.From what I remember from the real research I read on hydrogen injection the biggest benefit is running leaner and hotter which reduces NOx emissions. I think they proposed using exhaust heat to generate the hydrogen but I forget the exact process. It is important to separate this from the 'HHO' snake oil salesmen - a little electrolysis cell piped into the intake is never going to help.
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