Common Fault Diagnosis and Troubleshooting in Automotive Air-Conditioning Refrigeration System

With the rapid development of social economy and the continuous improvement of per capita income, people's consumption capacity has been greatly improved, and the frequency of automobile use has also been greatly improved. At this time, the performance of automobile air conditioning directly affects the comfort of motorists and riders, and will also have a certain impact on the overall performance of automobiles. Especially in the summer hot period, the automobile air conditioning refrigeration system is in the high intensity operation state for a long time, if does not carry on the timely overhaul and the maintenance, it is easy to increase the automobile air conditioning refrigeration system breakdown probability, affects the automobile air conditioning normal use. Therefore, this paper will briefly analyze the automotive air conditioning refrigeration system, and then analyze the common faults in automotive air conditioning refrigeration system, and put forward corresponding solutions based on this, better ensure the healthy operation of automotive air conditioning, hoping to provide some valuable reference for the majority of automotive air conditioning maintenance workers. 1. The Overall Working Principle of Automotive Air Conditioning Refrigeration System Automobile air-conditioned refrigeration system brings a little coolness to drivers and riders in the hot summer, gives people a better driving experience, effectively enhances people's comfort in summer driving, and can be said to be an indispensable part of the driving process of summer cars. However, the automobile air-conditioned refrigeration system needs a variety of equipment to ensure the normal operation, long-time use of automobile air-conditioning and no timely airconditioned refrigeration system maintenance work, it is easy to cause related failure problems, affecting the normal use of car owners. Therefore, it is of great significance to diagnose the common faults of automobile air-conditioned refrigeration system and put forward corresponding solutions to ensure the comfort of automobile operation. Figure 1 Automotive air-conditioned refrigeration system The automotive air-conditioning refrigeration system consists of condensers, compressors, evaporators, expansion valves, night-vision windows, liquid-storage dryers and refrigerants (see 2020 5th International Conference on Technologies in Manufacturing, Information and Computing (ICTMIC 2020) Copyright © (2020) Francis Academic Press, UK DOI: 10.25236/ictmic.2020.061 307 figure 1). When the automotive air-conditioning refrigeration button is turned on, the equipments work simultaneously to promote the continuous circulation of refrigerants in the tube, reduce the temperature in the car compartment, and bring a more comfortable feeling to people in the driving process. In the process of automobile air conditioning and refrigeration, the gas refrigerant is compressed by compressor at high temperature, then conveyed to condenser, in this process, the temperature is reduced, the high pressure condenser is formed, the liquid storage dryer is re-entered and filtered to ensure the purity of the refrigerant, then the expansion valve is used to reduce the pressure of the high pressure refrigerant into the evaporator, and the refrigerant is converted into the gaseous state. Finally, the internal temperature of the automobile is reduced effectively by the blower. The automobile air conditioning refrigeration system is a continuous circulation process, in the automobile this airtight space through the compression, the condensation, the drying, the evaporation and the transportation and so on link realizes the high efficiency refrigeration [1]. 2. The Common Faults of Automotive Air-Conditioning and Refrigeration System and the Troubleshooting Methods Figure 2 Automotive air conditioning refrigeration system The automobile air-conditioned refrigeration system has brought great help to the improvement of people's travel comfort, but the refrigeration system needs multiple components to work at the same time to achieve the effective refrigeration state (figure 2). If there is a problem with some refrigeration parts, it will have a very adverse effect on the normal operation of automobile air conditioning. At present, there are three kinds of common faults in automobile air conditioning refrigeration system, one is serious, the whole automobile air conditioning refrigeration system does not work at all, and the other two kinds of problems are more common in the daily automobile air conditioning refrigeration problems, one is the poor automobile air conditioning refrigeration, the other is the large noise during the operation of automobile air conditioning refrigeration system [2]. The following we will analyze the main causes of these three cases, as well as the corresponding fault solutions. (1) The automotive air-conditioned refrigeration system does not work at all The automobile air-conditioned refrigeration system does not work at all, which is a serious problem in the air-conditioned system, which directly affects the normal use of the automobile airconditioned refrigeration system, and also brings great trouble to the automobile driving and riding personnel. Figure 3 Automotive air-conditioned refrigeration system