The normal and safe operation of the chiller is inseparable from the refrigerant. So what factors should we consider when choosing a refrigerant?

First, thermodynamic performance

1. Have a moderate saturated steam pressure. Evaporation pressure should generally not be lower than atmospheric pressure, so as to avoid air leakage (in the case of screw chiller/air-cooled chiller/water-cooled chiller); the condensing pressure should not be too high, otherwise the system pressure requirements will be Increase, and will increase the power consumption; in addition, the ratio of condensing pressure to evaporation pressure should not be too high, otherwise it will lead to an increase in the compressor discharge temperature of the chiller.

2, to have a higher critical temperature (higher than the ambient temperature), so that it can be liquefied at normal temperature or normal low temperature, and will reduce throttling loss.

3. Have a lower solidification temperature. This prevents the refrigerant from solidifying at the evaporation temperature.

4. Have a higher thermal conductivity. This can improve the heat transfer coefficient of the chiller (in the case of a screw chiller/air-cooled chiller/water-cooled chiller) and reduce the heat exchange area, thereby reducing manufacturing and operating costs.

5. Have a smaller adiabatic index. This allows the compression process to consume less power and the compressor discharge temperature is not too high.

6. The refrigerant liquid is smaller than the heat capacity. This can reduce the loss of the throttling process.

Second, physical and chemical properties

1, to have a small density and viscosity, which can reduce the flow resistance loss of the refrigerant in the unit refrigeration system (in the case of screw chiller / air-cooled chiller / water-cooled chiller).

2. It is not easy to burn, explode, non-toxic, and it is not easy to decompose at high temperature, and it is not easy to corrode the metal parts of the chiller.

Third, economic performance

This is a more popular topic, which is both cheap and easy to obtain. For the Xudongsheng series of chillers, R22 refrigerant is generally used. Of course, R134a, R404A, etc. can also be used according to user requirements.