How to choose refrigerant for high and low temperature alternating damp heat test chamber

How to choose refrigerant for high and low temperature alternating damp heat test chamber

There are many kinds of refrigeration used in the high and low temperature alternating damp heat test chamber, and different refrigerants have very different uses and application ranges. Today, we will focus on explaining the main refrigerants on the market.

　　 One, low pressure and high temperature refrigerant

　　 Condensing pressure Pk≤2—3kg/cm (absolute), evaporation temperature T0>0℃. Such as R11 (Freon 11, CFCL3, a fluorine, its T0=23.7℃), R21, R114, its T0=23.7℃. This type of refrigerant is suitable for centrifugal refrigeration compressors of air conditioning systems. Usually at 30℃, Pk≤3.06kg/cm.

　　 Two, medium pressure temperature refrigerant

　　 Condensing pressure Pk≤20kg/cm (absolute), 0℃＞T0＞-60℃. Such as R717 (ammonia, NH3), R12, R22 (freon 22, CHCLF2, difluoromonochloromethane), R502 (an azeotropic refrigerant, composed of R22 and R115 (pentafluoromonochloroethane, C2F5CL)), etc. This type of refrigerant is generally used in ordinary single-stage compression and two-stage compression piston refrigeration compressors.

　　 Three, high pressure low temperature refrigerant

　　 Condensing pressure Pk≥20kg/cm (absolute), T0≤-70℃. Such as R23 (Freon 23, CHF3), R13 (CF3CL), R14 (CF4), carbon dioxide (CO2), R503, ethane, ethylene, etc. These refrigerants are suitable for the low temperature part of cascade refrigeration equipment or -70℃ In the following cryogenic device.

After reading the above content, we learned that -70℃ high and low temperature alternating damp heat test box, high and low temperature damp heat test box, high and low temperature alternating test box, high and low temperature test box, rapid temperature change test box, constant temperature and humidity test box , High and low temperature impact test chamber, ultra-low temperature test chamber high temperature part uses medium temperature refrigerant (R404A), and low temperature part uses low temperature refrigerant (R23). So the refrigerant is very important for the high and low temperature alternating damp heat test chamber.