Refrigerant Selection Techniques

The selection of refrigerants is a complex technical and economic issue that requires consideration of many factors. When selecting refrigerants, a comprehensive technical analysis should be conducted based on the specific situation.
1. Consider environmental requirements.
Refrigerants that comply with national environmental regulations must be selected.
2. Consider the requirements for refrigeration temperature.
Choose high temperature (low pressure), medium temperature (medium pressure), and low temperature (high pressure) refrigerants based on the different refrigerant temperatures and cooling conditions. The standard evaporation temperature of the commonly selected refrigerant should be 10 ℃ lower than the refrigeration temperature. The selection of refrigerants should also consider the cooling conditions and operating environment of the refrigeration device. The condensation pressure during operation should not exceed the specified value for safe use conditions of the compressor. Car air conditioners can only use external air as the cooling medium, and the factors that affect them, such as temperature, wind speed, solar radiation, and thermal radiation, are constantly changing. Their operating conditions determine that they can only use high-temperature (low-pressure) refrigerants. In the past, R12 was used, but when publishing documents, R134a was mostly used.
3. Consider the properties of the refrigerant.
Select refrigerants that are non-toxic, non explosive, and non combustible based on their thermal, physical, and chemical properties; The selection of refrigerant should have good heat transfer, low resistance, and good compatibility with the materials used in the refrigeration system.
4. Consider the type of compressor.
The working principle of different refrigeration compressors varies. A volumetric compressor increases its pressure by reducing the volume of refrigerant vapor, and typically uses refrigerants with a large refrigeration capacity per unit volume, such as R134a, R22, etc. There are many types of refrigerants, and with the progress of science and technology, new working fluids are constantly emerging to be suitable for different refrigeration devices.