Problems with high delta T

[cjkaat]

A thought i had for inducing a very high temperature differential in
a Stirling. Using a Solar Stirling device to power a Stirling
Cryocooler to produce and store liquid Nitrogen. Using the LN2 to
supercool the cold side of the Stirling, while using a conventional
fuel (Ethanol? Diesel?) to heat the hot side creating a much larger
temp differential than using say, ambient atmos temperature to create
the differential. Im not a physicist, im a machinist, and a Stirling
enthusiast, so im unable to do a thermodynamic analysis of the
system. Does anyone think this is a horrible ineffecient idea?.
Besides the possible thermodynamic inefficiencies, would the
materials for seals and heat transfer surfaces be able to cope with
the rapid expansion/contraction?. Just a thought I wanted to put out
there for analysis.

Cheers,

CJ

[cjkaat]

Just to add :
LN2 = -196°C (77 Kelvins)
Ignition temp of Ethanol = ~ +425°C (~698 Kelvins)
Delta T = ~620 Kelvins

I hope the values are correct... high school physics only

[steve_amorin]

Hello CJ,
I don't know if you remember me, I'm Steve, I was in your grade 7 class many years ago and wanted to apologize for being unkind towards you then. All the best to you.

[rgmco]

We think it is a very creative idea and believe it can be done, though perhaps in a slightly different manner. You have to keep the hot side operating temp below 600C to be able to avoid creep stress and premature failure of the hot heat exchanger.