What kind of snow is used in the constant temperature and humidity test chamber (What is the refrigerant for the constant temperature and humidity chamber)
Constant temperature and humidity test box can do low temperature test, and the low temperature test is necessary for the refrigeration of snow, there are a lot of snow on the market for refrigeration, such as R21, R114, R503 and so on, so, constant temperature and humidity test box refrigeration with what kind of snow? The following Xiaobian for you to solve this question.
Categories of snow on the market:
1. Low pressure and high temperature refrigerant
Condensing pressure Pk≤2~3kg/cm (absolute), evaporation temperature T0 > 0℃. Such as R11 (Freon 11, CFCL3, its T0 = 23.7℃), R21, R114, its T0 = 23.7℃. This type of refrigerant is suitable for centrifugal refrigeration compressors in air conditioning systems. Usually at 30℃, Pk≤3.06kg/cm.
Two, medium pressure and medium temperature refrigerant
Condensing pressure Pk≤20kg/cm (absolute), 0℃ > T0 > -60℃. Such as R717 (ammonia, NH3), R12, R22 (Freon 22, CHCLF2), R502 (an azeotropic refrigerant, composed of R22 and R115, C2F5CL), etc., this type of refrigerant is generally used in ordinary single-stage compression and double-stage compression piston refrigeration compressor.
Three, high pressure and 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., this type of refrigerant is suitable for the low temperature part of the cascading refrigeration unit or -70℃ below the low temperature device.
Constant temperature and humidity test chamber
The snow used in the constant temperature and humidity test chamber: one is R404A, the other is R23
Refrigerant R404A is a mixture of HFC125, HFC-134A and HFC-143. It is a colorless gas at room temperature and a colorless transparent liquid at its own pressure. R404A is suitable for low temperature new environmental refrigeration equipment, such as our high and low temperature test chamber, constant temperature and humidity chamber, rapid temperature change test chamber, cold and hot impact test chamber, walk-in test chamber, etc.
R23 refrigerant, with the molecular formula CHF3, is widely used in low temperature refrigerant. Generally, R404A refrigerant is used in single thermostat, and R404A and R23 refrigerant are used in double system thermostat.
The type of compressor is considered in the constant temperature and humidity test chamber
Different refrigeration compressors work differently. Volume compressor is to reduce the volume of refrigerant vapor to improve its pressure, generally choose large unit volume cooling capacity of refrigerant, such as R134a,R22 and so on. There are many kinds of refrigerants. With the progress of science and technology, new working medium is constantly appearing to be suitable for different refrigeration devices.
