The air conditioning screw bai unit is the du host of the air conditioning system. Because its key component zhi-compressor uses the screw type, it is called the screw type water chiller dao. The unit comes out of the evaporator as a gas refrigerant; after the compressor is adiabatically compressed, it changes Into a high-temperature and high-pressure state. The compressed gas refrigerant is cooled and condensed in the condenser at equal pressure. 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 substance 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. It is also the main working principle of the screw chiller.