1 reply to this topic

[jimmason]

snoopmarkymark writes in . . .

Message: would a hit and miss engine work with a gasifier? has anyone tried it?

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hi mark,

well, wood gas will work in nearly anything that has combustion and moves a piston.  however it does work much better in some versions of this basic arrangement than in others.  unfortunately, the hit and miss is likely one of the worst fits.

the problem is twofold.

1.  the gasifier needs a fairly consistent pull to keep up the correct internal temps and process conditions.  highly variable pull creates problems for a gasifier, and the hit and miss engines is about the worst for this.  even the puffiness of a single cylinder lister is best attenuated by a pony tank or big volume filter of some type between the gasifier and engine.

2.  the miss cycles are still going to pull a little gas through the system, and that gas is going to be high % co as this is wood gas.  even to the degree it is not pumping during the miss cycles, the gasifier is still hot and will be generating some positive pressure of gas even through not pulled, thus this is going to continue going through the engine.  both of these situations are going to release lots of co in the immediate run environment, which is very bad for the humans in the area, despite the machines not minding.

you can minimize this by running the engine near full power to minimize the miss cycles.  or, throttling the engine by some other means (butterfly plate, variable heating of intake fuel/air, timing advance/retard, etc), but then that violates the basic pleasure of the hit n' miss motor.

so in short, yes, it will work, but it's not going to give you much more than an interesting demo, from which i suggest you generally stand far away.

nonetheless, it will be interesting so of course you should try it.  do you have any pix of the engine over which you are considering this adventure?

j

[kenboak]

Mark, Jim,

I thought about hit and miss with woodgas on a CHP system.

Suppose only 20% of the woodgas is needed to run the engine for power, then you could use the 80% miss-cycles to compress the gas and pump it to a burner where you use it to raise heat.

Need to try it on the Lister - a diesel engine makes a great gas compressor if you phase the valves correctly.  Gas/air mix stoicometrically blended and fed to a burner at 20 atmospheres - what more would you need?


Ken