The closed refrigeration heating cycle device is used in industries with strict temperature requirements, which can combine heating and cooling functions into one. During the cooling and heating process, the temperature change in the temperature control device can be achieved by the circulation of the refrigerant to reach the temperature required by the process.

1. Close the high-pressure exhaust and low-pressure suction shut-off valves. Use the process valve needle on the compressor to discharge the refrigerant inside the compressor, so that the compressor crankcase is connected to the atmosphere; unscrew the oil drain plug at the bottom case of the crankcase, discharge the heat transfer oil in the crankcase, and remove the filter screen for cleaning; After the cleaned filter is dried, put it into the body, and tighten the oil drain plug.
2. Unscrew the plunger of the process port on the crankcase side of the compressor, use this as the filling port, and pour the lubricating oil into the crankcase through suitable tools; since the original system may have a certain amount of residual oil, it can be reduced when changing oil. Add some oil, usually to a position slightly higher than the lower limit of the oil mirror mark.
3. After the oil filling is completed, tighten the process plunger, connect the pressure gauge, and drain the compressor of the refrigeration unit; after vacuuming, open the high and low pressure shut-off valve of the compressor to check whether there is refrigerant leakage; if there is no leakage, wait for 20 minutes Start the unit.
4. If the oil level is lower than the normal range (1/4 sight glass), add lubricating oil. You can check the oil pressure by connecting an oil pressure gauge to the needle valve of the oil pump. The suction side pressure of the oil pump should be basically the same as the low pressure suction pressure.
5. Under normal circumstances, the heat transfer oil will be replaced after a certain period of operation, or in some other special circumstances.