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Old 10-06-2009, 07:22 PM   #17 (permalink)
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Quote:
Originally Posted by basslover911 View Post
"Maybe you can recover enough energy from your exhaust to generate pressurized steam and run a turbine, which in turn runs an alternator?"

Yes, like i've been saying, that IS the whole idea. Through natural convection the liquid will flow to spin a turbine and back into the heat exchanger.

And you ideally want the lowest possible exhaust velocity after this exchanger, because thats how you know you are extracting energy from the system (in the form of heat)- so low exhaust velocity would be a good thing not a bad thing...
Keep in mind, you have the efficiency of the engine to worry about, as well. You can't think of one system at a time, you have to think of both systems working together. Decreased exhaust velocity means higher back pressure, which is not good for your engine (unless it's a 2 stroke, of course, and then only to a given extent.)



Ideally, you could get 100% of the heat from the exhaust system. This would choke out the host engine, though, defeating the intended design.

Realistically, you probably won't be able to recover more than about 25% of the exhaust's heat without causing severe performance degradation.

You will want to shield and insulate the exhaust from front to back, to minimize the heat loss that isn't providing energy for your setup, which will help a few % with efficiency, and still allow you to have enough heat in the exhaust to maintain positive flow with minimal pressure build.
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