Stirling-Stirling Cooler

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Stirling-Stirling Cooler

Postby greattqn » Sun Dec 25, 2005 9:08 pm

ld I attach the cooling area (a metallic box) outside the I am trying
to build a Stirling-Stirling refrigerator. I propose to drive the
first Stirling using the heat from concentrated sunlight, which powers
a second Stirling to achieve cooling. I hope to get this machine to be
able to make ice.
I have a question about the Stirling cycle cooling though. I want the
Stirling engine to be able to cool an area of 10cm x 10cm x 10cm. I
know that a small gas compression chamber can yield better results, so
how do I go about cooling that area? Should I just attach the cooling
area outside the cooling gas chamber? Can I achieve a 0 degrees
celsius cooling with a Stirling built from scratch?
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Stirling Refrigerator

Postby stan.hornbaker » Mon Dec 26, 2005 8:36 am

A great idea. Too bad there is already a somewhat similar commercial on the market.
http://www.coleman.com/coleman/colemancom/detail.asp?product_id=5726-750
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Response to Stirling-Stirling Cooler

Postby greattqn » Mon Dec 26, 2005 9:25 am

Alright. Thanks. I am aware of the fact that there are many commercially available Stirling cycle coolers and even cryocoolers, such as the ones produced by the company that I think is called Global Cooling. However, I've searched around online and I haven't found a stirling-stirling cooler using solar power to drive another Stirling. I also heard that a solar stiring engine is far more efficient than a solar cell. Thus, I thought to combine the two stirlings to make 1 fridge that can be run on solar power. So basically it's a Stirling heated by the sun, that drives another Stirling to cool an area.
My main concern is how to build this thing. I can build the Stirling engines, but I want to have the second Stirling engine cool the inside of a metallic box with the dimensions of 10cm x 10cm x 10cm, thus acting like a fridge, and I should be able to put water in there or pop to let it cool =). So, how should I go about doing this? Should I simply attach the box outside the cooling (normally the heating)gas cylinder and let the convection of air inside the box do the rest? Or is there a better way to cool the inside of the box?
Thank you very much for your response!
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Response to Stirling-Stirling Cooler

Postby stan.hornbaker » Mon Dec 26, 2005 9:41 am

A commercial product would not be a market success as the solar heat source availability is too limited. Hence the battery powered product.

If building one is a matter of 'accomplishment' then by all means build one. Otherwise why expend time and energy on something of limited value in the marketplace.

The design of such a device might be of great instructional value. You will have to acquire some theoretical knowledge in the process. Thermodynamics in general and Stirling theory in particular.
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Response to Stirling-Stirling Cooler

Postby greattqn » Mon Dec 26, 2005 1:40 pm

I'm building it as a science fair project. I'm not seeking any money or patents from it of course, just as an "accomplishment". =)

I've done a fairly thorough search online about building Stirling engines, and I'll start with fairly easy ones that can be built without lathes and milling machines.

However, I still have a few questions, the answers to which I cannot find online, and thus I'm requesting an answer here.

1) Is there a way to use the relationship between the rpm of the Stirling engine and the temperature difference to calculate the lowest temperature that my Stirling cooler will reach? If so, how?

2) Is there a way to make the heat reject side only slightly hotter while the heat accept side (the cold side) a great deal colder? I don't want my fridge to turn into an oven on the heat reject side and only slightly chillier on the cold side.

3) This is a stupid question, but I can't find the answer to it. What exactly is a heater cap and why use it? I've seen a few designs on Koichi Hirata's site and I see a lot of his engines use the heater caps. Why? If I use an alcohol burner to heat it, then wouldn't it be in a very awkward position?

Thanks a lot for your response!
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Response to Stirling-Stirling Cooler (Science Fair)

Postby stan.hornbaker » Tue Dec 27, 2005 8:52 am

Let me suggest the following:

1. Read the Science Fairs information posted under LEARN on opening URL.

2. Have a working model Stirling engine for display. The Coffe Cup engine is ideal. Also need a coffee cup warming heater to keep it running.

3. A copy of "Around the World by Stirling Engine" on display.

4. Drawings/photos of real working engines.

5. Drawings of suggested Stirling engine applications, real or imagined.

6. Avoid an excess of unnecessary details.
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Response to Stirling-Stirling Cooler

Postby greattqn » Wed Dec 28, 2005 7:17 pm

Well, I thought this was a good idea...I maen, if used as a cooling system, then the hotter the object to be cooled, the colder the cooler becomes...Isn't that an ideal property for a cooling system to have?
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Response to Stirling-Stirling Cooler

Postby stan.hornbaker » Sat Jun 03, 2006 11:22 am

"...then the hotter the object to be cooled, the colder the cooler becomes...Isn't that an ideal property for a cooling system to have?

"...then the hotter the object to be cooled," then the MORE work to be done to cool the refrigerated space to the desired temperature.
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Response to Stirling-Stirling Cooler

Postby printmaxx » Sat Jun 21, 2008 1:29 pm

Did you build the engine & what progress did you make,
peter Wright
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