Air compressor for supercooling ?

[rossd]

It occurred to me that I could use my air compressor to cool my CPU.

I'd run the output air from the compressor through a radiator to get it down to room temp, then through some insulation to the "cold zone".

In the cold zone, I would have an expansion valve. The air coming out of the valve would be even colder, and would go through a block on the CPU to bring the temp back up to the cold zone temp. This would absorb the heat from the CPU.

Lastly, the air would go back out through the insulation to vent into the room.

The inflow and outflow tubes would need to be run very close to form a counter-flow heat exchanger. That way, the compressed air arrives at the CPU cold and the expelled air exits to the room at room temperature.

From quick calculations, I can see two hitches:

1. I would need an adiabatic expander for the expansion valve. These appear to be very complex. If I didn't use an adiabatic expander, the work done by the expanding gas would (I guess) be converted to heat, which would more than equal the cooling capacity of the system.
2. My air compressor seems to be too small by about a factor of four.

Has anyone ever tried this method or heard of anyone trying it ? It would seem to be a practical way of cooling about 200W at -50C, if you have a big compressor (1.6L/s at 100psi, if my calculations are correct).

Thanks,
rossd.

[Diggrr]

If you had a good, constant duty air compressor (I haven't ever seen one for home use) I'd try this instead:http://www.exair.com/spotcooling_products/cg_page.htm

Problem one:The heat generated in a home air compressor running constantly would cause the air to be heated to over 100F.

Problem two:You'd have to have a cooling system to your air compressor also. They're made for intermittent duty only, and inject oil into the air stream.

Problem three:The cost of parts and electricity would make it cheaper to buy a chest freezer.

Not trying to be a spoil sport, I've thought of it too. But in the research I found serious problems getting any payback. That vortex tube is pretty sweet, but again needs a constant duty compressor (read: watercooled, pressurized oil system, 440v).
The only thing close would be a scroll compressor for a heat pump, and those aren't usually constant duty either.

Sorry man. :(

[rossd]

I looked at those vortex tubes. They're pretty cool. Thanks for the link.

It looks like I'd need at least a $1300 dollar compressor to get a 50C drop at 200W. It seems peltiers are a better deal.

Thanks,
rossd.

[mw521]

I can get you a nice continuous duty medical air compressor, oilless, with a built in air dryer for oh, say 8000.00 bucks. I have three that I have built from old ones. Come on over and get it. you want a 20 or 30 gallon tank on it?