Constant temperature and humidity machine is a kind of equipment used to test the performance of materials in various environments, as well as to test the heat resistance, cold resistance, dryness and moisture resistance of various materials. Equipment refrigeration principle: the refrigerant is cut off by the compressor and compressed to a higher pressure, consuming work to increase the exhaust temperature. Then, the refrigerant passes through the condenser and isothermal heat exchange with the surrounding medium, transferring heat to the surrounding medium. The refrigerant is then cut off and expanded through a shut-off valve to perform work, i.e. to lower the refrigerant temperature. The refrigerant absorbs heat from the warmer object through the evaporator, thus lowering the temperature of the object to be cooled. Repeat this cycle to achieve the purpose of cooling.
1. Check whether the data transmitted from the temperature sensor of the laboratory constant temperature and humidity machine to the instrument is normal. Otherwise, the compressor will not start.
2. Check whether the alarm protection function is normal and whether the compressor starts to run. Check the pressure gauge of the compressor to see if the refrigerant in it is leaking. If the refrigerant is less, detect the leakage and replenish the refrigerant before lowering the test chamber normally.
3. As the laboratory constant temperature and humidity machine adopts the compound stack refrigeration method, if one of the compressors can not work properly, it may also lead to the equipment can not be lowered normally. Check whether the compressor control system works normally, and whether there is any noise or abnormal sound in the operation of the compressor, which leads to not being able to lower the position.
4. Check whether the condensing fan operates normally, whether the dust in the air inlet is too thick, whether the circulating fan of the laboratory constant temperature and humidity machine operates normally, whether the AC contactor of the compressor and the thermal overload protector are damaged, whether the solenoid valve in the pipeline is open, and whether the solid state relay of the heating system is damaged, which affects the cooling system.
According to the refrigeration principle of the above laboratory constant temperature and humidity machine, the refrigerant flows in the system. When the state changes, with the phenomenon of exothermic and heat absorption, the temperature of each refrigeration component and pipeline will change. We can judge whether the laboratory constant temperature and humidity machine is working properly.
How to deal with the abnormal situation found in the operation of general constant temperature and humidity machine?
1. If any abnormality or burning smell is found during the test, it should be stopped in time for inspection.
2. Find out the reason for the abnormality of the constant temperature and humidity machine. If you cannot repair it by yourself, ask the manufacturer to repair it.
3. During the high or low temperature test, if the equipment stops running for a specific reason, the door can be opened only after the equipment returns to normal temperature.
Constant temperature and constant humidity machine belongs to precision instruments, and some small situations will inevitably occur during operation. How to quickly solve the problem and make the test enter the normal state is not only a kind of ability of the operation manager, but also a kind of embodiment of the quality of the enterprise staff.