How to judge the leakage of refrigerant in the high and low temperature test chamber?
Under normal circumstances, the high and low temperature test box will work according to the set time and temperature, but when the equipment is used for too long or improper operation, it is likely to cause the temperature of the high and low temperature test box to slow down, we will teach How do you judge the leakage of refrigerant in the high and low temperature test chamber?
1. First, observe whether the refrigeration compressor of the high and low temperature test chamber can be started during the operation of the test chamber, and the compressor can be started during the operation of the environmental test equipment, indicating that the electrical wiring from the main power supply to the compressors is normal, and the electrical system is There is no problem.
2. If there is no problem with the electrical system, continue to check the refrigeration system. First, check that the discharge and suction pressures of the low-temperature (R23)-stage compressors of the two sets of refrigeration units in the high and low temperature test box are lower than normal, and the suction pressure is in an evacuated state, indicating that the main refrigeration unit is insufficient in the amount of refrigerant.
3. Touch the exhaust and suction pipes of the R23 compressor of the main unit of the high and low temperature test box again by hand. It is found that the temperature of the exhaust pipe is not high, and the temperature of the suction pipe is not low (no frost). It also shows the lack of R23 refrigerant in the host group.
Fourth, the cause of the failure has not been determined, and the cause of the failure is further confirmed in conjunction with the control process of the test chamber. The test box has two sets of refrigeration units. One is the main unit and the other is the auxiliary unit. When the cooling rate is large, the two groups of units work at the same time. At the beginning of the temperature maintenance phase, the two groups of units still work at the same time. In the temperature maintenance phase, once the auxiliary unit stops working and the main unit has no cooling effect, the air in the test chamber will rise slowly. When the temperature rises to a certain level, the control system will start the auxiliary unit to cool down and reduce the temperature to the set point. Near the fixed value, then the auxiliary unit stops working again. If this is repeated, malfunctions will occur.
To sum up, it has been confirmed that the cause of the failure is the leakage of refrigerant R23 from the low temperature (R23)-the class unit of the main unit of the high and low temperature test chamber. Check for leaks in the refrigeration system. Check with a combination of a leak detector and soapy water. It is found that the valve stem of the hot gas bypass solenoid valve has a crack of about 1cm. Replace the solenoid valve and refill the system with fluorine.