Predictive Analytics And Evaluation Of Air-conditioning Fatigue Reliability Under Complicated Conditions

Air conditioner tubing fatigue damage is one of the main reason of conditioner failure. The fatigue reliability is directly related to the quality of AC. The compressor working process includes start-up, steady running and stop, but the major research of AC tubing fatigue focus on steady running phase. During transition working condition such as start-up and stop stage, the speed of compressor rotor will surpass resonant frequency of compressor, which will cause the amplitude and stress of pipes larger than those under steady conditions, and the damage induced can not be ignored. Meanwhile, the fatigue reliability of pipes is influenced by assembly process and other error caused factors, so it is necessary to consider many factors when evaluate the performance of pipes.Based on the structure characteristics of compressor, excitation load trait during start-up phase is analyzed. Combined with the linear transmission relationship between inlet and outlet displacement response and excitation load, the form of excitation during start-up phase is identified as impulse excitation and reserve algorithm of excitation load is proposed which shows transient excitation peak time and peak load can be calculated. The virtual prototype model is built up in FEA software using critical information extracted from compressor tubing system. Thus, pipe dynamic characteristics of compressor piping system under start-up and steady phase can be obtained using reversed excitation load.Based on the simulation of ANSYS software and physical prototype test, the influence of some machining errors such as the weight error, pipeline deformation, insertion depth and the mute cotton on modal response of AC is studied, which provides fundamental basis for AC production craft standard establishment. And a fatigue life forecasting methods which takes start-up phase pipes fatigue damage into consideration is proposed based on variable frequency air-condition fatigue reliability analysis. In this way, the prediction accuracy of conditioner tubing fatigue reliability evaluation is improved.