waste heat engines

[muffildy]

So anyone know of any good engines that run off of waste heat created by a cars engine?

[ConnClark]

check this one out

Rotary Steam Engines: Page 9

[Diesel_Dave]

Look into Detroit Diesel's turbo compound system on it's new DD15 engine (15 liter engine).

[muffildy]

those look neat
cant seem to find anyplace that actually sells just the waste heat part though.

[oil pan 4]

A turbocharger.

[cnc]

AFAIK (edit ) it's a big problem to transform heat info other type of energy efficiently.
I can't propose ready to use device - only just my random thoughts. I've read something about hybrids with turbines making power for electric motors. Maybe you could borrow some ideas from them You could run small steam turbine, produce el. energy, then run an air compressor (and use the heat again), store the compressed air and use it to push pistons, let say, every second cycle. Probably you would have lots of additional issues on the way of course. It would be very complex and expensive also. Cost vs. gain could be too small to think about it seriously but hey! it's an idea

PS
Don't take me too seriously please.

BTW
Maybe it would be even better to simplify the setup. Put turbo, place high rpm high compression pump instead standard compressor and pump the air into accumulator for compressed air injector. You coould also use a heat from exhoust collector, turbo and pump. Sorry for wild imagination

[Steaming]

I was thinking of scaled-up Peltier Devices that would take the heat and convert it to electricity. There is a company that makes such a device calling them Thermal Electric Generators (TEG) based in Morgantown, WV. Thermoelectric Generator

Makes me speculate about wiring a bunch into a small woodstove and throwing it into the back of a Honda Insight or something lol. I suspect there would be power/weight ratio problems, but maybe these could be sorted out.

[diesel_john]

Deere is claiming 18.93 hp-hr. per gal. at the pto. It has one or more heat recovery devices.

JOHN*DEERE 8320R TRACTOR SETS FUEL EFFICIENCY RECORDS AT NEBRASKA TEST

But diesel-electric as in rail or marine applications is probably more efficient over all. One challenge in automotive is running the engine at optimum load all the time. So a tiny diesel generator, storage device, and a electric drive.