Glass or Aluminum for Lunar Mirror

>
> > --- In ssi_list@... Ian Woollard
> > > ;-)
> > >
> > atmosphere and capture the heat and use for other
> > processes, i.e.
> > energy generation through steam. If there is an
>
> State of the art steam engines are 10% to 20%
> efficient. You will still have to dissipiate 80% to
> 90% of the heat via radiators. And even the steam
> engine load will dissipate heat which still needs
> radiation.
>
> What "other processes" did you have in mind ?

Pure speculation on my part because I'm not an engineer. From my
understanding, heat is either a waste product or a requirement,
depending on what you're doing.

So, how about a sterling engine generating electricity. I've seen
35% efficiency figures. Also, a solar furnace vaporizing lunar
regolith. A vacuum is maintained inside the furnace but the furnace
itself is placed inside of a industrial facility with an atmosphere.
Water is circulated around the furnace to draw off heat. That steam
is then circulated through a steam engine (20% efficiency) to create
electricity to run an electric arc furnace, an aluminum
electrolysis process or a H2O electrolysis process. The remaining
waste heat is ciruclated through the concrete floor of the base
(i.e. radiant heating technology ) because a buried base enounters a
thermal envirnoment of -20C during day or night. Also, the heat is
circulated through the hydroponics area, food processing, chemical
processing which are endothermic and also sent to a thermal heat
sink to be used during the lunar night.

If a lunar facility is designed with a mission in mind, rather than
a hodge-podge of missions added with no thought to integration,
then, just as with a closed envirnoment life support system, the
lunar base designers should be able to design a system which is as
close as possible to a "waste heat closed environment industrial
support system" :) WHCEISS. Why radiate away heat from one process,
only to have generate heat for another process. Also, try to design
so that the process moves the heat from the most heat-intensive
process to the least.

Also, if the industrial process on the moon assigns priority to
extracting Iron, aluminum and titanium and has an abundance of
excess silicon oxide, then within the industrial facility (with an
atmosphere) why not pump the heat into the material, then move the
material out into the vacuum of your lunar storage pile.

Of course, every option has trade-offs and challenges. But if heat
rejection is still an issue after employing a WHCEISS process, then
the trade-off between a waste heat radiating system being designed
into the plant against a "take the hot material out to the lunar
surface" strategy might make for an interesting
cost/benefit/efficiency analysis.