After the leak test of the refrigeration system is completed, it should be filled with refrigerant. However, the Freon refrigeration system must be vacuum dried before being filled with refrigerant. When the drying is not complete, the refrigerant cannot be filled. The method of filling refrigerant is as follows:

　　(1) The filling of refrigerant should first be carried out on the high-pressure side. Connect the refrigerant liquid bottle to the filling valve of the system. Before tightening the filling valve connector, open the liquid bottle valve to flush impurities and air in the pipeline.

　　(2) Put the refrigerant bottle head down, or tilt it at least 30 times. place. It is best to place it on a platform scale and adjust its angle continuously as the filling progresses so that all the liquid is drained, and the filling amount can be measured at the same time.

　　(3) Cooling water is passed to the condenser and the cylinder liner of the cold storage refrigerator.

　　(4) Close the bypass valve of the dryer, open the inlet and outlet valves of the dryer, and conduct the solenoid valve in the system.

　　(5) Open the refrigerant bottle valve slightly, and when the pressure in the system rises to 2～3kj/cm2, check again for leaks everywhere.

　　(6) After everything is normal, turn on the refrigerator, but pay attention to the suction pressure not to be too low. When the suction pressure is lower than Ok/cm2, the operation of the refrigerator should be stopped and restarted after the pressure rises. When using a water-cooled evaporator, pay attention to the temperature and flow rate of the cooling water to prevent freezing.

　　(7) After the filling is completed, stop the operation, close the filling valve, open the bypass valve of the dryer, and close the inlet and outlet valves of the dryer.

　　In the process of filling the refrigerant, as the temperature of the refrigerant bottle decreases, the pressure also decreases. At this time, warm water can be used to increase the pressure, and no fire or steam heating is allowed. For Freon refrigeration systems, the desiccant should be replaced immediately after filling.