Alpha free piston engine as a cooler (prototype)

[bladeattila]

Hi there,

I started to make a simple but effective Stirling cooler just for fun. The base is a cheap aquarium air pump from RESUN (ACO-003).
I hacked it a bit, closed the holes are there, took off some valve, insulate the great aluminium piston with styrofoam. The piston diameter is 45mm, the maximum stroke is 15mm at 50Hz. The engine has a 30mm length stainless steel mesh regenerator. Hot side heat exchanger made from 30 pcs offlat aluminium heat pipes L= 200mm H= 5mm The air gap between the pipes: near by 0,35 mm. I molded it together with 2 components polyurethane.
The cold side hasn't got HX actually, but no insulation anywhere. The other parts are PVC

The free piston is a motocycle rubber boot accordion. The length is 100 mm. The accordion's end is flexible fixed to the base rods because it is adjustable. We can adjust the phase shift for a great performance. This part is not insulated also.

The engine works well with high noise factor actually, because the non fixed end.

The next step an another passive heat exchanger for the cold side, because I need to use it for a mini refrigerator cabinet. Just for fun. :)
The HX will be same as the hot side's HX.

The engine' input electrical power was under 30W. Working gas was air with atmospheric pressure.
The test video was recorded outside of the room. The temperature was 0˙C.
The hot side stayed under 19 ˙C, The cold side going under -50˙C after 118 sec.

I haven't got any chance for a perfect measurement of COP, or cooling power or capacity. I need to build this for my old and bad refrigerator cabinet as a "heart".

Thanks for your attention!
Blade

https://www.youtube.com/watch?v=Rh39l054Aec

[Ian S C]

Is it an ALPHA in as much as it has two, one hot, and one cold pistons, and no displacer, from your description you have a displacer and power piston, and if they are in one cylinder it is a GAMA type.
What ever, you seem to be getting results, and that's what matters.
Ian S C

[bladeattila]

This is an Alpha. No displacer in. One drived piston on the hot side, and one free (rubber boots piston) on the cold side. That's all!

[bladeattila]

More informations are here: http://manson-ericsson-hae.blogspot.hu/ ... rling.html