Thermodynamics

[infinity12358]

why don't we have a pole of super conducting material connecting a large body of water to space - thus creating free super cold water which can be used by power plants? apart from the logistics of getting a long enough pole and getting it to stand up, of course. theoretically, would it work? this theoretical pole could connect the ocean to space as well, thus reducing the temperature of the ocean - although you'd have to have the ability to disconnect it at will, or the whole ocean would freeze over!

[DevilSolution]

Well they certainly have strong enough and simaltaniously conductive enough materials, the costs are ridiculous though. Were talking about making minute amounts in the lab, maybe there are more practical materials but im not aware.

[imatfaal]

Not really sure about this - but i think you would basically only be losing heat to vacuum of space via bb radiation - and that aint that great at 200-300k. I think you would be talking about a couple of hundred watts per square metre - which isn't gonna be enough to provide aircon for the maintenance team let alone anything useful

[Enthalpy]

Same opinion: works in principle, not in figures.

 

No good heat conductor exists. No material exists that supports its weight over 300km height.

 

Please don't tell me "graphene" nor "nanotube". At that scale, polypropylene is just as good. At the scale of a rope, nanotubes will be as bad as plastic.

 

Heat emission will be limited by the blackbody efficiency, or 315W/m² at 273K. That a very hard limit to any cold sink in space, say for a nuclear reactor or RTG; designers look for hotter hot sources because no cool air is available - or they imagine huge cold sinks, nearly immaterial, of flying droplets or moving plastic films.

 

No use for big power. BUT nice uses for free real cold at tiny power:

 

Ground-based telescopes "see" a background temperature linked with the Universe more than with Earth - after a difficult design effort. This means that the background makes less noise in the receiver than if an antenna points to the ground. Can be <20K.

 

On astronomy space probes, CCD retinae can sometimes be cooled for free, if very well insulated, provided their thermal radiation interacts with cold space rather than the spacecraft. Can be <50K.

[infinity12358]

Cool, thanks for the thoughts! So radiation isn't good enough to remove enough heat to be significant. Bums!