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yet another two stroke diesel

yet another two stroke diesel engine but with gas turbine driven ancillaries and water injection.
  [vote for,

Starting with fuel rich burning, and pushing the piston down.
Near the bottom of the power stroke an exhaust port is uncovered
After the exhaust port is covered by the return stroke, of the piston, the fuel is injected.
This fuel is being injected into a red hot mixture of exhaust gasses, in witch there is no oxygen because the previous combustion was to rich. This fuel can not burn because of the lack of oxygen, but it will be subject to partial pyrolysis This pyrolysis should make this engine tolerant of just bout any fuel that dose not clog up the injectors.
This exhaust / fuel mixture is compressed and heated adiabatically .
ignition is caused by injecting a controlled amount of water and air. The mixture would need to be kept rich, to ensure an oxygen deprived environment for the next charge of fuel.

At a temperature of over 1400 K the water and fuel under go the water gas reaction.
If the correct amount of water is used it will;
Increase the volume of gas, and there for the pressure in the cylinder.
increase the amount of combustible hydrogen and carbon monoxide in the exhaust gas.
Prevent soot formation.
And recover heat from the cylinder, that would normally have to be dumped by the cooling system. By virtue of the overall endothermic nature of the water gas reaction.

The fuel / energy that is lost from the engine, as a result of running so rich. Is recovered by using the combustible exhaust in either a gas engine to drive the; compressors, injectors, etc. or in a gas turbine to generate, and have electrically driven ancillaries

j paul, Jul 07 2011



       1) Just because three things all work well on thier own does not mean they will all work better if you glue them together.   

       2) Running a diesel engine rich fouls the valves, rings, ports, heads, injectors, manifold, and just about every other part of the engine in short order. I fail to see how adding water will help this, unless you intend it as some sort of "steam clean" cycle.   

       Bear in mind that my experience with diesel engines is limited to big snarling razorbacks like the one in my Deuce, not the new-fangled computerized super-high-tech deals coming out in high-performance cars these days, but I'm reasonably certain that the principles are still the same.
Alterother, Jul 08 2011

       I dont know if it would work but I love it! +
DIYMatt, Jul 09 2011

       Your expertise far exceeds mine. and as you have easily spotted this is a Frankenstein monster, bits from here and there.   

       The starting idea was ignition by injecting air into hot fuel.   

       The water injection serves two functions.
1] it prevents the formation of soot and tar, by means of the water gas reaction.
2] it absorbs heat that would otherwise be wasted and stores it as useful chemical energy.
The temperature at witch the water gas reaction happens is about (1400 K) the water is turned into hydrogen and the soot is turned into carbon monoxide.

       On a more speculative note, if the diesel gets hot enough to produce a lot more hydrogen and therefore electricity than is needed for its ancillaries, then it might lend its self to hybrid driving.   

       I can not swear that this will work. Only that the parts look viable.
j paul, Jul 09 2011

       The cold air into hot fuel idea is sound and I like it, especially applied to a compression-only ignition like a diesel. If I could effeciently pre-cool the intake on my Deuce (which I can't, because any viable method short of packing dry ice around the manifold would consume more energy than it would serve to produce, yada yada...), it would probably improve the performance by a noticable degree.   

       In my opinion, water-injection is wasted on diesels performance-wise, but there are probably droves of gearheads who would vehemently disagree with me on that point. I'm sure we'll be hearing from them soon. Given your elaboration on the other proposed benefits, I guess I'm not really qualified to evaluate your theories about prevention of residue build-up and thermal retention/recovery, so somebody else can weigh in on that.   

       As for running a rich mix, I understand how it's fairly intrinsic to your concept, but I still say it's a mistake. I'm not an engineer or an automotive expert, but I've cleaned a lot of injectors in my days.
Alterother, Jul 10 2011

       Its a non starter if it can not be run rich.
Oxygen in the exhaust mix will mean premature deflagration when the fuel is injected.
j paul, Jul 12 2011

       I didn't say it can't be run rich, I just said I wouldn't. I don't know, maybe this would work like you speculate; as I said, I'm not an engineer. My area of expertise is more on the other end of things... Specifically,the end where stuff breaks and somebody pays me to fix it. Unless it's my stuff, in which case it's either a hobby or a major pain in my ass, depending on what's broken and what time of day it is.
Alterother, Jul 13 2011


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