Is one of the biggest difficulties with nuclear power in space the need to cool the steam that's used to spin the turbine? Since space is cold, couldn't you just send coolant outside and cool it so it can cool the steam?
Where's that room temp superconductor Niven wrote about?
You might build a one megawatt reactor that weighs 500 pounds and need four times that much mass in radiators to get rid of the heat.
Quote from: scienceguy on 01/21/2009 06:25 pmIs one of the biggest difficulties with nuclear power in space the need to cool the steam that's used to spin the turbine? Since space is cold, couldn't you just send coolant outside and cool it so it can cool the steam?On Earth, heat from reactors and steam turbines is dumped by convection (or conduction) to large external heat sinks, such as the atmosphere or cooling ponds.In space, you can't use a heat exchanger, there is nothing to exchange heat with. Instead, you have to radiate the heat away with large radiators, which is much less efficient.Mark S.
IMHO first you would use the heat for process heat and possibly for habitat heating.For the residual heat, would it be possible to dig or drill some holes in the lunar soil, bury some pipes carrying a heating medium and get rid of the heat this way - just like a heat pump on earth but the other way round.Would that be a possibility?
Quote from: nomadd22 on 01/21/2009 07:30 pmWhere's that room temp superconductor Niven wrote about?In the same place were you can find the 'unobtainium' used to construct Ringworld. (Ok, not quite the same implausibility level)
Quote from: Bejowawo on 01/22/2009 02:32 pmIMHO first you would use the heat for process heat and possibly for habitat heating.For the residual heat, would it be possible to dig or drill some holes in the lunar soil, bury some pipes carrying a heating medium and get rid of the heat this way - just like a heat pump on earth but the other way round.Would that be a possibility?An old saying I have heard many a time, nothing is a better insulator than 100' of rock. The problem with that is you will be pumping heat in and it would not be coming out. Meaning the temperature of you lunar soil will soon be the same temp as your pipes. So much for a radiator. It makes a good way to store heat, but a bad radiator.Ever notice that caves stay a constant temperature year round, mid 40's in NY, upper 40's in PA, low 50's in WV... This is why.
Quote from: kevin-rf on 01/22/2009 05:21 pmQuote from: Bejowawo on 01/22/2009 02:32 pmIMHO first you would use the heat for process heat and possibly for habitat heating.For the residual heat, would it be possible to dig or drill some holes in the lunar soil, bury some pipes carrying a heating medium and get rid of the heat this way - just like a heat pump on earth but the other way round.Would that be a possibility?An old saying I have heard many a time, nothing is a better insulator than 100' of rock. The problem with that is you will be pumping heat in and it would not be coming out. Meaning the temperature of you lunar soil will soon be the same temp as your pipes. So much for a radiator. It makes a good way to store heat, but a bad radiator.Ever notice that caves stay a constant temperature year round, mid 40's in NY, upper 40's in PA, low 50's in WV... This is why.Actually that's much more a function of thermo mass vs insulation with the rock.