The low temperature test chamber is generally implemented by a cascade refrigeration unit according to the low temperature environment of -60 ° C to -100 ° C according to industrial production and scientific experiments. The cascade refrigeration unit consists of two single-stage compression systems. The high temperature stage uses R404A, the low temperature stage uses R23 as the refrigerant, and the high temperature stage produces the cold quantity for the low temperature refrigeration cycle condensation. It can be seen that the cascade refrigeration system is a complex system of two sets of interconnected and interacting compressors, condensers, evaporators, expansion valves and many equipment accessories. Therefore, once the low temperature test chamber refrigeration system fails, attention should not be focused on only one local or certain level, but a comprehensive inspection and comprehensive analysis of the entire system. This requires the accumulation of practical experience and theoretical guidance. Through the long-term practice summary, we have explored a lot of experience in checking faults and summarized them into the "one-view, two-listening, three-touch" inspection methods of the cascade refrigeration unit. It is a powerful basis for analyzing and judging faults, and it is a quick overhaul. Good means.
A look: look at the indications of the pressure gauge and the thermometer, see the amount of lubricant to see the frosting of the evaporator and the suction pipe.
Second listening: It is to listen to the operation of the compressor unit and abnormal phenomena, listen to the noise of the compressor operation, and listen to the sound of the expansion valve.
Three touches: the degree of heat and cold of the piping and related components of the system, as well as the condensation of the compressor and the condition of the unit.
Shaoxing Guanglin Textile Co.,Ltd , https://www.sxguanglin.com