Best way to turn hot air into kinetic or electric energy
Best way to turn hot air into kinetic or electric energy
(OP)
So I know that you can use energy recovery units (heat plate, heat pipe and energy recovery wheels) to reclaim the heat in air, but it only puts it back into the air (like in winter conditions).
What if you wanted to turn the heat in air into kinetic or electric energy?
Hot air turning fans (mini-turbines?) and charging batteries?
Just thought we could kick around some ideas... thanks!
What if you wanted to turn the heat in air into kinetic or electric energy?
Hot air turning fans (mini-turbines?) and charging batteries?
Just thought we could kick around some ideas... thanks!





RE: Best way to turn hot air into kinetic or electric energy
Stirling engine.
RE: Best way to turn hot air into kinetic or electric energy
One thing that I've been thinking of is using the heat of compression in a compressor (pull 250-300F gas off upstream of the cooler) to make steam that can drive a turbine. The numbers work, but even with a really big compressor you don't get a lot of kW out the back end. This sort of combined cycle can increase your system efficiency by 5-10% which is nothing to sneer at, but it isn't huge.
David Simpson, PE
MuleShoe Engineering
www.muleshoe-eng.com
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RE: Best way to turn hot air into kinetic or electric energy
No reason it couldn't run a generator.
RE: Best way to turn hot air into kinetic or electric energy
As far as heat output, we are probably looking at 60,000-100,000 BTU/h coming out of a space approximately 3-4 sq. ft. Not exactly sure of the CFM of hot air as of yet.
Thanks!
RE: Best way to turn hot air into kinetic or electric energy
RE: Best way to turn hot air into kinetic or electric energy
The efficiency of most thermoelectric conversions are incredibly poor, and brute-force, to boot.
TTFN
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RE: Best way to turn hot air into kinetic or electric energy
an ericson cycle (closed gassturbine loop) would need a much bigger delta T (>500°C)
a stirling engine would probably work on paper, however imagine a teacup stirling model engine.
and multiply kw "your project"/kw model ratio with the surface area of the displacer piston
or the surface area of the heat exchanger.
recovery wheel heat recovery efficiency is around 95%
cost savings = 0.95 x cost fuel/ kW x kW "your project"
rotating energy heat recovery efficiency is around 30%
cost savings = 0.25 x cost electricity/ kW x kW "your project"
(if you manage to recover more than 1/4 of the waste energy into electricity, have a run to the patent bureau)
RE: Best way to turn hot air into kinetic or electric energy
RE: Best way to turn hot air into kinetic or electric energy
RE: Best way to turn hot air into kinetic or electric energy
RE: Best way to turn hot air into kinetic or electric energy
A 100,000 BTU steam has less than 20 KW or $3.00 US per hour in electricity or $1.00 in natural gas.