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Has anyone made a solar heat powered Fluidyne stirling engine air pump? Answered

So, I will start with what I have in mind.  (Might be total rubbish because I don't fully understand).  You have a solar collector box, not more than 1 meter square.  painted black 1 to 2 cm deep,   and probably with glazing over top. The box itself is metal fully closed up and the back is insulated.  From the box through the insulation there are some metal tubes that go to another box at back for the cooling chamber. Tubes are constricted so the air sprays through to the cooling box and it goes into steel wool as it expands. On the reverse stroke, it does not go so much through the steel wool because the nozel constriction is  on that side not the hot side.   Power is taken away from a liquid piston somewhere attached to both chambers  or a diaphragm at the back. (It can be water cooled). I want the strokes to be long and slow.
Can it work?   Temp difference will only be around 40 degrees C and the pumped air ( 2 valves  in chamber off of liquid piston) only needs to go to 2 psi. )    I have been in contact with a guy in Germany who made Sterlings that worked with sun heat.    But he didn't use Fluidyne (also called liquid piston stirling) and he did not pump air.          My specs are extremely low, I only need 60 litres per hour of air at 1 or 2 PSI.  It would be very cool to make it from such basic materials.                 Thanks Brian


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Russell McMahon
Russell McMahon

2 years ago

6 years on :-)

My son and I made several Fluidynes many years ago (probably 20+).
We used an electrically heated resistor, but solar heat would be viable.
You want max temperature difference possible, and with care you should be able to get a delta T well in excess of 40 C.

A fun method may be to use a cylindrical evacuated tube solar collector and use the hot tab as the heat source.

I'd be interested to know if you ever ended up making a Fluidyne 6 years ago.

Russell McMahon


8 years ago

Not ready to make a freehand design? That would be much clearer.