Michel Jullian wrote,
Sterling draws 1000W heat from hot reservoir (not necessarily water
BTW) and outputs 150W mechanical. Heat pump draws 150W*9=1350W from ambient air and outputs them to the
hot tank. Net power into the hot tank: 350W
The figure of COP=9 may have occurred in print, or in a lab somewhere,
and may be the ultimate goal to shoot at - but the people who do this
for a living (use the Linde process to make LOX etc) ... like, well,
Linde - they say that they can achieve a COP of about four in practice,
but that is using a water heat sink (river) and that is a different kind
of COP, from the "free energy" variety, in that the "sink" itself is not
usable as heat.
If you try to segment the stages for use in a heat engine (the most
efficient Linde process uses six stages, I believe) then the COP goes
down further below four.
I think that a useful COP using the Linde for both heat and cool
convesrion would be 2.5 and that is why I said earlier "if you can give
me a Stirling with 40% Carnot efficiency using 100C water, then I can
guarantee a self-runner."
Of course this shifts the burden of proof for OU to the Stirling engine,
because since the Carnot spread is only 100 degrees above ambient, the
maximum possible efficiency is nowhere close to 40%. That is why I
called it "magic," but in truth you will find people who think that the
Stirling can exceed these limitations.
I hope that they are correct, but the proof is lacking, so far.
Jones
