low temp engine question

Discussion on Stirling or "hot air" engines (all types)
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tapkoote
Posts: 13
Joined: Fri May 17, 2013 12:04 pm
Location: Washington State USA

low temp engine question

Post by tapkoote » Mon May 20, 2013 3:21 pm

I've ordered one of those cheap coffee cup engines.
I've got an old black cast iron pot in the sun in the window
it registers 87.5 degrees, think that motor will run on that?
Pat :question)
If the hammer didn't work
you have an electrical problem

theropod2
Posts: 147
Joined: Tue Aug 16, 2011 5:05 am

Re: low temp engine question

Post by theropod2 » Mon May 20, 2013 5:08 pm

tapkoote wrote:I've ordered one of those cheap coffee cup engines.
I've got an old black cast iron pot in the sun in the window
it registers 87.5 degrees, think that motor will run on that?
Pat :question)
Yep, BUT there must be a temperature difference, so the cool end might need to be shaded some.

If these little engines will run off the heat from a computer monitor surely your solar collector iron pot will suffice as a heat source. Is this one that's supposed to run off the heat of your hand?

Take and upload pictures!

R

Hopper
Posts: 54
Joined: Fri Feb 08, 2013 6:54 pm

Re: low temp engine question

Post by Hopper » Tue May 21, 2013 3:46 am

Best solar LT Stirling I have seen had a clear Perspex top disc instead of the usual aluminium.
The top of the displacer piston was covered in matt black aluminium foil or thin sheet.
So the sun shone through the top of the displacer chamber and heated the black alum. on top of the displacer piston.
Cold end was the usual aluminium disc, but at the bottom of the displacer chamber, sat on a paving stone for cooling.

But the problem you face is the heat coming up from the cast iron pot and the heat coming down from the sun. You will need to somehow shade the cold end of the engine but leave the iron pot in sunshine.

tapkoote
Posts: 13
Joined: Fri May 17, 2013 12:04 pm
Location: Washington State USA

Re: low temp engine question

Post by tapkoote » Wed May 22, 2013 2:06 pm

Thanks if I get it to work I'll post a pic
Pat
If the hammer didn't work
you have an electrical problem

tapkoote
Posts: 13
Joined: Fri May 17, 2013 12:04 pm
Location: Washington State USA

Re: low temp engine question

Post by tapkoote » Mon May 27, 2013 11:45 pm

While working on my POP can engine, I received my low temp engine.
It ran over an hour on a cup of nuked water, 3 hour 50 minutes on one quart nuked (2 min)
H2O.
Haven't the sun to heat the black pot, but did get it on the wood stove.
Not enough heat differential.
How ever I'm going to super glue some cooling fins on the spokes.
Thinking the fan action will over come the force of the fan blades.
Probably nuts- HUH?
I've got -128 rpm-135rpm-127 rpm (in that order) on the thermos.
Thats about an hour into it.
I'll do some tests with hot 2:30 min water with and without cooling fan blades.
And I'm thinking on a way to concentrate the heat off the wood stove/plus the
fan action may get this to work on the stove. (however summer is almost here)
I think.
Here's 3 hours 50 minutes----- excuse the quality, I'm learning the vid thing.
If the hammer didn't work
you have an electrical problem

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