Newbie Stirling Question

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gzoller
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Joined: Tue Jan 03, 2006 3:38 pm
First Name: Greg
Last Name: Zoller

Newbie Stirling Question

Post by gzoller »

Hello,

Living in Texas I noticed it is extremely hot in my attic space in the
long summer months. Using the temp difference between my attic (say
120-130 degrees F?) and the earth's constant below-ground temp be
enough to drive a practical Stirling engine to power any form of
useful A/C? Forgetting about electricity generation, would the
kinetic energy of the engine be enough to drive the compressor in a
high-efficiency A/C?

Greg
stan.hornbaker
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Attic Stirling engine A/C?

Post by stan.hornbaker »

The air temperature would be sufficient to run a model or demonstration engine but there would not be enough power output to drive any useful refrigerator system. Power producing Stirling engines have to have a high temperature on the hot end. 1,000 deg. F for starters.
If a successful Stirling driven A/C system were practical/possible they would be in production.
ontuyalex
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Last Name: Hardwick

Response to Newbie Stirling Question

Post by ontuyalex »

Ok I am assuming that cost isn't a factor. I know it is...but I don't know how much this would cost, so here's an idea without a thought of money.

Make a heat exchanger and put it underground where it's cooler. It could be something simple like uninsulated pipes that come from above the surface, then undergound to cnake back and forth (to increase surface area). This will chill the pipes to ground temperature. Put a Stirling powered fan in the Air pipe and have it run on the temperature difference of the cold air and the hot attic (or soil if it stays hot enough). Basicly Geothermal.
stan.hornbaker
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Response to Newbie Stirling Question

Post by stan.hornbaker »

The temperature difference, delta-t between an attic at 130 deg.F and ground temp of something on the order of 65 deg. F is only 65 degrees which is totally inadequate to power a practical Stirling engine.

A Stirling engine heat pump would require mechanical power input.
Basically accelerating the flow of thermal energy from the attic to
the ground at the expense of mechanical power drive input.


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