Surface Frost Treatment Method for High and Low Temperature Circulating Box Compressor

The refrigeration compressor of the high and low temperature cycle box is a passive fluid machinery that elevates low-pressure gas to high pressure. It is the heart of the refrigeration system. It sucks in low-temperature and low-pressure refrigerant gas from the suction pipe, compresses it through the motor driven piston, and discharges high-temperature and high-pressure refrigerant gas to the exhaust pipe, providing power for the refrigeration cycle. During the low-temperature testing of this device, it is occasionally observed that the compressor freezes. What is the reason for this?

1、 Equipment process pipe * idle: The process pipe of the high and low temperature test chamber is not sealed or repaired in a timely manner after opening. *When the ice is left idle and frequently turned on, moisture in the air will be brought into the machine from outside the pipe.

2、 Unseal compressor: It is reported that compressors placed without sealing can also freeze if they are replaced with frost without drying treatment.

3、 Damaged refrigeration evaporator: It is understood that after the refrigeration evaporator is damaged, the water molecules in the freezing (storage) chamber, along with the water vapor in the air, are brought into the compressor when it is turned on (negative pressure is generated in the evaporator when it is turned on, and atmospheric pressure brings water molecules in the humid air into the machine), which can also cause icing.

4、 Poor ventilation of evaporator: In addition, if the ventilation of the evaporator in the high and low temperature test chamber is poor and the cooling capacity cannot be carried away, it will also cause frosting or freezing of the evaporator, resulting in low pressure and causing frosting of the compressor housing.

5、 Lack of refrigerant: Due to the insufficient amount of refrigerant, the low evaporation pressure of the evaporator leads to a low evaporation temperature, which gradually causes condensation on the evaporator to form an insulation layer and transfer the expansion point to the compressor return air, resulting in frost formation on the compressor return air.

6、 Excessive refrigerant: When there is too much refrigerant in the system, the liquid level in the condenser is high, the condensation heat exchange area is reduced, and the condensation pressure increases. That is, the pressure before the expansion valve increases, and the amount of refrigerant flowing into the evaporator increases. The liquid refrigerant cannot evaporate in the evaporator, so the compressor sucks in wet steam, the cylinder head is cold or even frosts, and may cause "liquid hammer". At the same time, the evaporation pressure will also be high.

6、 Accidentally compressing water vapor into water: In addition, if the compressor in the high and low temperature test chamber leaks during pressurization, compressing water vapor in the air into water and injecting it into the pipeline can also cause icing.

Overall, proper operation and regular maintenance management are of great help in reducing equipment failures and abnormal situations, as well as extending equipment lifespan. In addition, during the development and manufacturing process of high and low temperature test chambers, attention should be paid to the rationality of design.