Share how to replace the lubricating oil and filter drier for the chiller

1. Persiapan

Check whether the compressor lubricating oil has been preheated for more than 8 hours. The oil heater is energized and heated for at least 8 hours before the test run to prevent the refrigerating oil from foaming during startup. If the ambient temperature is low, the oil heating time needs to be relatively longer. When starting at a low temperature, due to the high viscosity of the lubricating oil, there will be situations such as difficulty in starting and poor loading and unloading of the compressor. Generally, the minimum temperature of lubricating oil must be above 23℃ to run the chiller, start it, record the operating parameters and analyze the machine’s previous and current problems, and make preparations.

1. Short-circuit the high and low pressure difference switch, (it is better not to adjust the pressure difference switch, you can directly short the two wires) when the machine is running at full load (100%), close the angle valve. (Pay special attention to the recovery of the differential pressure switch after the refrigerant is recovered)

2. When the low pressure pressure of the chiller is less than 0.1MP, press the emergency switch or turn off the power. Since there is a one-way valve at the compressor exhaust port, the refrigerant will not flow back to the compressor, but sometimes the one-way valve may not close tightly, so it is best to turn off the compressor exhaust cut-off while pressing the emergency switch valve.

2. Replace the filter drier

When the above work is completed, turn off the main power supply and proceed with the following procedures:

（1） Drain the oil. The freezing oil sprays quickly under the pressure of the system refrigerant gas. Take care not to splash outside. Drain the refrigerant while draining the oil, and open the high pressure gauge shut-off valve.

（2）Clean the oil tank and the oil filter, open the oil tank cover, clean the oil tank with dry gauze, throw the waste refrigerating oil into the gauze when the gauze is dirty, take out the two magnets in the oil tank, clean it, and put it back into the oil tank. Disassemble the oil filter with a large wrench and clean it with waste oil.

3. Replace the filter drier:

A) There are 3 filter elements of the filter drier, and the replacement speed should be fast to prevent too long contact with air to absorb too much moisture.

B) The filter is packaged in a can. Pay attention to protection during transportation. Once the package is found to be damaged, it will be invalid.

3. Vacuum and refuel

According to the compressor structure of industrial chillers, it is best to refuel from the high-pressure side. Because the compressor’s high-pressure and low-pressure chambers are not directly connected, it is difficult to return the oil from the low pressure to the oil tank. Generally, we use a vacuum method to evacuate oil from the low-pressure side to suck in the oil from the high-pressure side.

Replenish the dead pipe: use the replaced waste refrigeration oil to replenish the dead pipe.

4. preheating

Power-on preheating, at least heat the oil to a temperature above 23°C before it can start up and run.

Water chillers include box-type air-cooled chillers/water-cooled chillers, screw chillers, open chillers, and low-temperature chillers. The structure of each type of chiller is different. If the chiller needs maintenance or repair, you must find the chiller manufacturer, who has a free one-year warranty service, or find a more professional repair point near the factory. Do not disassemble the chiller privately. operate.