Precautions for the replacement of refrigerating oil in the cooling system of the vehicle charger

The cooling system of the on-board charger should pay attention to the condition of the refrigerating oil during the operation. After the compressor is started, carefully observe the changes in the oil temperature and oil pressure. If the oil changes color, the oil must be changed until the system is clean. The cooling system of the on-board charger that is normally put into production and operation, after a long period of operation, requires a limited period of maintenance and replacement of refrigerating oil.

1. Refrigerating oil replacement operating procedures
1. Close the high-pressure exhaust and low-pressure suction shut-off valves, and use the process valve needle on the compressor to release the refrigerant inside the compressor, so that the crankcase of the compressor communicates with the atmosphere.
2. Unscrew the oil drain plug at the bottom of the crankcase, drain the refrigerant oil in the crankcase, and remove the filter for cleaning.
3. Nitrogen can be blown in from the low-pressure inflation valve needle, and the oil discharge port can be blocked by hand to increase the pressure in the machine body, and further remove the residual oil in the machine body. Dry the cleaned filter and put it into the machine body and tighten the oil drain plug. .

2. Frozen oil injection
Option 1: Unscrew the process port plunger on the side of the compressor crankcase, use it as a filling port to pour the refrigerated oil into the crankcase through a suitable tool;

Option 2: (for piston machine) connect the low-pressure pipe of the fluorine-filling meter to the low-pressure process valve needle of the cavity of the piston-type refrigerator, use a vacuum pump to pump the crankcase to negative pressure, and remove the other fluorine-filling pipe separately, one end Insert it into the container containing the refrigerated oil, and connect the other end to the valve needle of the low-pressure suction end of the oil pump, and suck the refrigerated oil into the crankcase by using the negative pressure in the crankcase.

Description:
1. It can be added less when changing the oil and refueling. Generally, add it to a position slightly higher than the lower limit of the oil sight glass mark.
2. After the refrigerating oil is filled, tighten the process plunger or remove the fluorine filling tube, and connect the fluorine pressure gauge to vacuum the compressor.
3. After the vacuum is completed, open the compressor high and low pressure shut-off valve to check whether there is refrigerant leakage.
4. After turning on the cooling system of the on-board charger, check the compressor lubrication and the oil level of the sight glass immediately. If the oil level is lower than the normal range, add refrigerating oil. If necessary, connect an oil pressure gauge to the needle valve of the oil pump to check the oil pressure.
5. The suction side pressure of the oil pump of the semi-hermetic piston compressor should be basically the same as the low pressure suction pressure, and the allowable value of the oil pressure difference.

Precautions:
The refrigerated oil in the cooling system of the on-board charger is hygroscopic, and the moisture in the oil chemically reacts with the oil. It is required to be particularly careful when working to minimize the air entering the system and the oil storage container; adding refrigerating oil should not be excessive, if excessive adding refrigerating oil, There is a danger of liquid shock when the cooling system of the on-board charger is turned on again.