09-17-2016, 08:20 PM
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#141 (permalink)
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Master EcoWalker
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The simple main reason why diesel yields better MPG than gasoline is that it is heavier per liter. You get way more carbon atoms in a gallon of diesel than in gasoline.
If it would compare per weight the difference is still there, but about halved. High compression rate and no pumping losses, as mentioned.
I can see how mixing in Browns gas would increase flame speed in some cases. I cannot see how the stability of the process can be maintained, I suspect the mixture would widen the variety that occurs in the combustion process. If you adjust for the pinging that might occur on some strokes, it may burn slow on others.
My brother in law was working on a small generator project. They could not get the combustion process stable, it kept misbehaving in some conditions despite all the effort they put in it. Variance in the fuel properties was the main cause; the minute amount of biofuel mixed in created havoc for that application, straight mineral was fine - but not guaranteed to be on supply.
Just to show how much engineers have to strive towards stabilizing the combustion process and to point out what should be your main concern when trying to mix in any kind of fuel the engine was not designed for.
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09-17-2016, 08:26 PM
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#142 (permalink)
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Full sized hybrid.
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Quote:
Originally Posted by JSH
Where will the electricity come from to power the electrolysis.
It won't. HHO is the equivalent of putting a wind turbine on top of your car to generate electricity to power the car.
In the case of HHO you are burning gasoline in a engine at 25% - 30% efficiency, to power an alternator and generate electricity at about 40-50% efficiency, to create hydrogen to burn in the car.
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I completely understand that. But what if you could run an AFR of 25:1, 50:1, or 100:1 or leaner in a gasoline engine and still get complete combustion. You could practically eliminate the throttle valve and eliminate pumping losses through it. Slight amounts of hydrogen have the potential to aid spark ignited combustion to the point that ultra lean AFRs could be obtained and still be running a homogenous air/fuel mixture.
Quote:
Originally Posted by oil pan 4
You never heard of propane, natural gas or alcohol intake fumigation?
Well its pretty cool.
If you are looking for a slight MPG boost less soot and for the engine oil to stay cleaner then propane is the way to go.
Natural gas is for stationary applications or when high pressure natural gas for on road applications is available.
Alcohol fumigation also known as a hot shot system is more for boosting power.
Then there is also water mist injection.
Besides that everything you need to know about water injection is here:
Water injection - EcoModder
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Yes. Propane fumigation does seem like a better choice than HHO to me right now. For one, with HHO you are converting every gallon of fuel into much less fuel of a different form. It would be like buying a gallon of liquid hydrogen for about 10 times or more the price of a gallon of gasoline. A gallon of liquid propane costs about the same as a gallon of gasoline or diesel and has close to the same energy density too.
I'll still have to research propane. The question that comes immediately to mind is how well will propane ignite and burn at really lean AFR's?
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09-17-2016, 09:07 PM
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#143 (permalink)
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Corporate imperialist
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The heat and pressure from the diesel injection burns off the propane.
Your propane A/F ratio is around 50:1.
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09-17-2016, 10:23 PM
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#144 (permalink)
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AKA - Jason
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Quote:
Originally Posted by Isaac Zackary
I completely understand that. But what if you could run an AFR of 25:1, 50:1, or 100:1 or leaner in a gasoline engine and still get complete combustion. You could practically eliminate the throttle valve and eliminate pumping losses through it. Slight amounts of hydrogen have the potential to aid spark ignited combustion to the point that ultra lean AFRs could be obtained and still be running a homogenous air/fuel mixture.
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If you understand that you can't get free hydrogen from water you are way ahead of most HHO proponents.
It sounds to me like you looking to do something similar to HCCI. Lots of engine / automotive companies are working on that technology but none to date have been able to create a working engine that can run at various loads / RPM. Controlling the ignition process has proven to be very difficult.
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09-18-2016, 01:34 PM
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#145 (permalink)
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Quote:
Originally Posted by oil pan 4
The heat and pressure from the diesel injection burns off the propane.
Your propane A/F ratio is around 50:1.
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Ok. 50:1 isn't bad at all. I wonder how well a 20:1 or leaner AFR total of gasoline and propane, with less propane than gasoline, would work in a spark ignited engine. Hydrogen seems promising on that it can burn at extremely lean AFRs.
Quote:
Originally Posted by JSH
If you understand that you can't get free hydrogen from water you are way ahead of most HHO proponents.
It sounds to me like you looking to do something similar to HCCI. Lots of engine / automotive companies are working on that technology but none to date have been able to create a working engine that can run at various loads / RPM. Controlling the ignition process has proven to be very difficult.
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Of course you're not going to get more energy from the hydrogen. For every gallon of gasoline (131,760,000J) you only get around 19,764,000J of mechanical energy, which when conveyed to electricity in an alternator will be about 14,823,000J of electrical energy, which when used to make hydrogen in a homemade electrolysis device you get around 4,446,900J of hydrogen energy. Then when that hydrogen energy is burnt in the engine it will produce on its own about 667,035J of mechanical energy, which is about a 97% loss, not gain.
BUT, if this could help the rest of the fuel burn more efficiently then there could be a benefit. For an example an ignition system takes electrical energy and produces a sparks for the combustion cycles. Now the spark isn't strong enough to drive the piston. But it does help, or should I say cause, the fuel to burn. And even though there's already a spark in some engines adding two sparkplugs per cylinder increases overall efficiency, even though you're using twice the energy to fire two sparkplugs.
Now as far as sparkplugs go they've already been proven. What I've said about HHO so far is pure speculation and I'm not convinced it will improve efficiency. The only way I can see it improve efficiency is if it could help a gasoline engine burn super lean.
Here's kind of an idea. You have a gasoline engine that runs for the most part like any other gasoline engine. Then when cruising along at low loads it goes into lean burn mode by adding more air along with small amounts of a flammable gas. The flammable gas then propagates the flame caused by the sparkplug throughout the whole cylinder so that all the gasoline burns up.
From what I've read hydrogen would work well for such a system. The potential problem with HHO is whether or not it could produce enough volume of hydrogen without becoming to much of an energy absorber itself. And of course there are the challenges behind storing hydrogen so as to not have to produce it while driving.
Propane is an alternative, but how lean can propane burn in a spark ignited engine?
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09-18-2016, 09:14 PM
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#146 (permalink)
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Full sized hybrid.
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After doing some research on propane engines and propane propagation I'm dumping my HHO theory for now and am getting really enthused about doing this both to my 1985 diesel Golf and and to my gasoline/petrol 1972 Beetle. Looks like propane will run at a 30:1AFR no problem. The question comes up whether I should convert the Bug completely to propane or experiment with the hybrid gasoline/propane mix idea.
I wonder if my 23:1 compression ratio in my 1.6L diesel engine would present a problem with propane irrigation.
Looks like I might need to move my thoughts to different thread.
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09-19-2016, 12:39 AM
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#147 (permalink)
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Corporate imperialist
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I have ran propane on my diesel engine that has a 22:1 compression ratio.
Does the diesel have a turbo?
One of the problems with trying to burn hydrogen in a gasoline engine is hydrogen doesn't burn it explodes even in air through a very wide range of concentrations and it ignites with very little energy input. Adding hydrogen to a gasoline engine would be like trying to inject diesel, in effect lowering the gasolines octane rating.
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1984 chevy suburban, custom made 6.5L diesel turbocharged with a Garrett T76 and Holset HE351VE, 22:1 compression 13psi of intercooled boost.
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09-19-2016, 12:45 AM
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#148 (permalink)
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Ok. I think I'll shoot the final bullet into the dead mythical unicorn. According to this hydrogen can improve lean burn characterizes of methane engines, but only if it consists of at least 20% of the total mixture (I'm not sure if that's mass or volume.) With that being said I doubt gasoline would be much better. If you'd need 20% hydrogen and 80% gasoline to make the hydrogen effective as a lean burn catalyst you'd need one hell of a super efficient hydrogen generator in order to outweigh the losses and at the same time the engine better be super efficient, like 50% efficient, to begin with. In which case you're not likely going to get any more efficiency anyway.
As I keep doing the math, if hydrogen can help create a lean burn gasoline engine it would likely be much more efficient and therefore cheaper to simply buy tanks of hydrogen and hook them up to your car. Propane can burn down to a 30:1 AFR (spark ignited) and it's more readily available, so I think I'll start with that.
Last edited by Isaac Zackary; 09-19-2016 at 12:52 AM..
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09-19-2016, 12:48 AM
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#149 (permalink)
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Full sized hybrid.
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Quote:
Originally Posted by oil pan 4
I have ran propane on my diesel engine that has a 22:1 compression ratio.
Does the diesel have a turbo?
One of the problems with trying to burn hydrogen in a gasoline engine is hydrogen doesn't burn it explodes even in air through a very wide range of concentrations and it ignites with very little energy input. Adding hydrogen to a gasoline engine would be like trying to inject diesel, in effect lowering the gasolines octane rating.
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No, no turbo. Yet anyhow. I kind of dream of getting one some day.
I hear you with hydrogen. It's touchy stuff. I think in a super lean burn operation the combustion chamber temperatures could be made low enough to use it. But it's not looking good for hydrogen right now, at least to me.
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09-19-2016, 04:54 AM
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#150 (permalink)
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Master EcoModder
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Quote:
Originally Posted by Isaac Zackary
If you'd need 20% hydrogen and 80% gasoline to make the hydrogen effective as a lean burn catalyst you'd need one hell of a super efficient hydrogen generator in order to outweigh the losses and at the same time the engine better be super efficient, like 50% efficient, to begin with.
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Which is basically what anyone and everyone looking at the various methods of combustion enhancement already knows.
Honestly... water is already an effective method of enabling ultra-lean burn... there's no need to go the extra step of splitting it into oxygen and hydrogen through a wasteful, energy-intensive process.
Bosch Water Injection Designed to Cut Fuel Consumption and Carbon Emissions
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