Heat Management Solution

[HeckuvaTester]

First off: If this is in the wrong section of the forums, please move it.

I recently had an idea for heat management of the satellite. Assuming that this would be an airtight cube with an earth-like atmosphere (or at least some gas), we could run small water pipes around the craft. If we have a Peltier Junction (http://en.wikipedia.org/wiki/Thermoelectric_effect) that has water piper running around both sides, we can control the ratio of water that passes the hot side to that passing the cold side. This would affect the temperature of the water, therefore affecting everything's temperature. It would use very little energy, and it could be set in a feedback loop with a computer (Raspberry pi would be good for this). Just putting this idea out there!

Any feedback welcomed.

[specialforcesguy]

It sounds good and workable, other than the water on the hot side very well may be boiling.

[HeckuvaTester]

We may choose to run them at less-than-full power, to prevent boiling of the water, and lower power usage.

[Newt]

Well, water boils differently at different pressures. . . I suppose we would be at lower pressure than where most of us live, so the heat threshold will be lower, at least like a high altitude Earth location. But we do not need to use water, do we? Why not ammonia, or some other more suited liquid? Most probably there will be no contact between the water in the heat management system and the water in the habitat, so we could put anything we wanted in the former, really.

[NERVAfan]

Ammonia has other concerns though... this will be a "minor" secondary payload so we may have stricter rules on potentially hazardous chemicals.

[cdugas4]

Water adds a good bit of weight. A Peltier thermoelectric cooler/heater should be what we use. It should be thermally connected to the exterior wall of the spacecraft to transfer heat to the exterior and that heat will dissipate via thermal radiation out into space on the surfaces that aren't exposed to direct sunlight. On the inside, radiative fins will transfer the heat to/from the air filling the craft. Air movement shouldn't be difficult considering we have a spinning structure inside the craft stirring up the atmosphere.

We should at some point run some sort of model or actual prototype test to determine the thermal properties of the craft while running and in a vacuum environment. I can only make an educated guess that there will be a large difference in the thermal properties (and thus the direction the Peltier device will need to "pump" the heat) based on the way we control the craft and orient the solar panels.