The screw unit produces a gas refrigerant from the evaporator; after adiabatic compression by the compressor, it becomes a high-temperature, high-pressure state. The compressed refrigerant undergoes isobaric cooling and condensation in the condenser, transforming into a liquid refrigerant. It then expands through a throttle valve to a low pressure, becoming a gas-liquid mixture. The liquid refrigerant at low temperature and low pressure absorbs heat from the cooled substance in the evaporator, reverting to a gaseous state. The gaseous refrigerant is then piped back into the compressor to start a new cycle. These are the four processes of the refrigeration cycle, which are also the primary working principle of the screw-type chiller.