摘要
Abstract
The HVAC(Heating,Ventilation and Air Conditioning)system is an important system of trains,the main functions include ventilation and temperature regulation,its refrigeration effect directly affects the comfort of passengers.Since the operation of a certain city metro,there are many types of refrigeration failures,including the fault of refrigeration circuit itself,and compressor and auxiliary equipment problems.In addition,there is no feedback on the air conditioning controller of the"hidden"faults.Targeted improvements need to be made.For the continuous and periodic low-pressure faults of the refrigeration circuit,the short-circuit low-pressure switch and the forced opening bypass solenoid valve are used to investigate and locate the fault area.For compressor overcurrent faults,the status of the thermomagnetic circuit breaker and the compressor are checked according to the fault frequency.For some"hidden"faults,the opening of the return air valve is checked,the abnormal noise of the pipeline is auscultated,the air conditioning mode is checked,etc.For low-pressure switch faults,it is necessary to improve the welding strength during installation.For the failure of the expansion valve,stainless steel sheath protection is added at the capillary connection.For the overcurrent fault of the compressor,the setting value of the thermomagnetic circuit breaker needs to be adjusted or the compressor needs to be replaced.In view of the small refrigeration capacity,it is necessary to strengthen the cleaning and lubrication of the return air valve,change the bushing,and adjust the abnormal pipeline position.In view of the abnormal mode,the judgment logic of the air conditioning controller can be added,so that the maintainer can intervene in time.The improvement has guiding significance for future investigation ideas and optimization plans.关键词
地铁列车/空调系统/制冷故障/膨胀阀Key words
metro trains/HVAC/refrigeration malfunction/expansion valve分类
交通工程
