The principle of screw chiller: Screw chiller is named as screw chiller because of its key component-compressor. The unit is made of gas refrigerant from the state of the evaporator; after the compressor is adiabatically compressed, it becomes high temperature High pressure state. The compressed gas refrigerant is cooled and condensed in the condenser at equal pressure, and after condensing, it changes into a liquid refrigerant, and then expands to a low pressure through a throttle valve to become a gas-liquid mixture. The liquid refrigerant under low temperature and low pressure absorbs the heat of the material to be cooled in the evaporator and becomes gaseous refrigerant again. The gaseous refrigerant re-enters the compressor through the pipeline and starts a new cycle. These are the four processes of the refrigeration cycle and the main working principle of the screw chiller.