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Quick and dirty solar heat engine design...

D

Day Brown

Jan 1, 1970
0
We been talking about laying an 8'X8' square of black plastic on the
ground, covering it with clear, sealing the edges, and sealing a 4"
plastic downspout pipe in a trench from underneath that will deliver
air at ground temp (15deg C) to be heated by the sun... to 50C.

Carnot sugests that the heated air will go from 14.7 to 16.6 PSI, that
is, 2#/sq in above atmospheric pressure. with nearly 6 sq meters of
area, that should total... tons. With solar energy of 1kw/sq meter, it
should heat the air pretty quick.

Charlie has a saw mill to cut lath to make a lattice to lay over the
clear plastic that will be lifted as the air inside expands. Which could
push upwards on a pyramidal frame to actuate something like a walking
beam engine.

If the walking beam is hooked to a fly wheel, then at the top, a flap
valve would open to vent the pressure, and the inertia would push it
back down again to expell all the hot air, and further begin to suck
cool air in from the bottom inlet pipe. At which point the inlet air is
heated by the sun....

Seems like it'd be slow, but torqueeeee. I can see that dropping the 4"
air feedpipe down the air space above the water in an 8" well casing
mite deliver lotsa cool air, be we dont have a well. We could cover a
large area of shaded ground with plastic, then covering that with mulch
to also provide a cool air inlet. The weeds'd hold the plastic up over
the ground, at the same that it it blocks the sunlite to kill them.
But any other options?
 
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