Nitrogen freezes about 10K higher than oxygen. So if you're trying to chill
LOX close to freezing, it's not an effective coolant.
On Tuesday, November 8, 2016, Henry Spencer <hspencer@xxxxxxxxxxxxx> wrote:
On Mon, 7 Nov 2016, George William Herbert wrote:
Well, on the plus side, He is gas at O solid temps so you can cool with a
gas loop welded to the tank exterior, inside external insulation...
Unfortunately, cryogenic He is not a great heat-transfer fluid: very low
specific heat, very low density (unless you use quite high pressures). I
think it would be a challenge to get adequate cooling with a simple helium
loop. Cryo specific heats are generally lousy, which puts a premium on
density, and LN2 is roughly three orders of magnitude denser than helium at
LOX-ish temperatures.
Henry
