Abstract: The compressor is the core component of the air conditioner, and its normal operation directly determines the use effect of the air conditioner. With the increase of the price of bulk raw materials and the increasingly fierce price war in the air conditioner market, the major air conditioner manufacturers are trying to apply various new technologies to the development of the air conditioner, so as to reduce the cost of the air conditioner, such as the application of aluminum tube heat exchanger, aluminum motor and small displacement compressor. Mainly study the application of miniaturized compressor in cabinet type air conditioning, and the abnormal attenuation of capacity occurs in the application process. In order to confirm the root cause of the problem, a number of visual mirrors in the system are added and relevant experimental test research are conducted. During the test, the state change phenomenon of refrigerant in different positions of the system in the experimental prototype is observed and recorded. Combined with the relevant experimental data, comprehensive analysis is carried out to find the root cause of the problem, so as to find the improvement or solution to the problem.

Key words: Air conditioning, Compressor, Capacity attenuation