Morphing Air Conditioner into Autocascade System

[mytekcontrols]

Here are my results with the AC-2 unit under actual operating conditions at High Vac (approximately 2x10-6 Torr).

• Comp Suction Pressure = 26 psig
• Comp Discharge Pressure = 148 psig
• Comp Discharge Temperature = 67.1C
• Condenser Air Temperature = 21.8C
• Compressor Suction Temperature = 0.5C
• Veeco MS-17 Cold Probe = -139.6C

I had to boost up the refrigerant charge to completely work the cold probe (forgot about radiant heat load coming from the walls of the cold probe vacuum chamber). Here is my estimate of the present charge:

• 7oz R123
• 4oz R22
• 85psi R170
• 85psi R14
• 45psi Argon

The 1oz boost in the R22 really helped to make a better connection between the low and the high stages of the autocascade, and can also be seen in the moderate pressures, even though more gases were added.

If I get a chance I'll try to do a complete recharge with this new charge to verify repeatability under the same conditions. Judging by the compressor pressures, it appears that there may still be room for more Argon and even lower temps.