Why does the low temperature small refrigeration unit run out of oil?

If it is found that the low temperature small refrigeration unit has run out of oil, analyzing the problem from the principle is basically related to its structure. Why does the low temperature small refrigeration unit run out of oil?

Some refrigerators on the market are made by mixing refrigerant oil with refrigerant. Due to the different density and weight of refrigerant oil and refrigerant, it is possible to use an oil separator to separate the unit refrigerant oil from the refrigerant, and then allow the refrigerant to return to the compressor through a full liquid evaporator. This new type of refrigeration effect is quite good, but the simple problem is that oil leakage may occur.

When the cooling water temperature is low, the degree of superheat during startup is not high, and then due to incomplete separation of the refrigerant, a mixture of refrigerant oil and refrigerant will appear. Together, they enter the heat exchanger, resulting in low pressure and even severe conditions that can lead to clogging of the expansion valve, making it impossible for a small low-temperature refrigeration unit to start.

What should we do? If it is found that there is a decrease in the classified oil level, the unit should be immediately switched to manual control mode, so that the compressor can be constrained by its energy, and the condensing pressure can be increased to always lower the low pressure alarm value of the unit to the allowable range. This can ensure that the unit is in a state where it will not be shut down and can still be started as much as possible.

If the above operations are carried out, it is found that the oil level of the low temperature small refrigeration unit is still very low, and the evaporator pressure is also very low, it is necessary to consider whether all the oil has gone into the evaporator. At this time, you can check the evaporator to see whether there is a lot of white foam rolling in the liquid crystal. If there is, it means that the oil is in the evaporator.

Therefore, it is necessary to conduct regular monitoring on small low-temperature refrigeration units to prevent various problems in the process of application.