Research And Optimization Of Mini-car Air-conditioner Pipeline System

With the rapid development of the automotive industry, vehicle production is increasing year by year, people's requirements to the vehicle's overall performance are also rising, especially the comfort of the vehicle has become the basic requirement. As an important indicator of the evaluation of the comfort of the vehicle, The performance of vehicle air conditioning system has become an essential accessory system in the car. So there are higher demands of the reliability to the processing technology, such as sealing design, leak detection technology and other aspects of the Air-conditioner pipeline. Now, the micro-cars have become the major trends of the domestic automobile due to the price advantage. But at the same time, the performance of micro-car air-conditioning is restricted by the cost control. And air conditioning piping leak detection technology is an important aspect of the enterprise productivity, which directly restricts the refrigerant filling efficiency and performance of the air conditioning, so it become more and more important.In this paper, it analyzes the leak detection process and parameters of the micro-car air conditioning systems by the research of the leak detection methods of the filling process in a mini-car. And find out the main reason for restricting the efficiency of the refrigerant filling is the high false positive rate of the vacuum leak alarm equipment. Around this aspect, this paper launched the following content:(1) Using ANSYS to analyze the sealing of the pipe joint of the automobile air conditioner piping system. And through the analysis of the differences of the sealing of the pipe joint between the two stages of joint seal performance which are air tightness test and vacuum leak, to find the reasons of good air-tightness in the test but small leakage in the vacuum.(2) According to the structural differences between the fittings to analyze the structural parameters'influence of the sealing performance. And complete the structural optimization of the joint by the compression ratio, trench depth, the gap between the groove and the sleeve.(3) Combined with the theory of static boost method of vacuum leak detection technology to do the packing test of the model air-conditioning piping systems, to analyze the trend of the nonlinear and linear packing characteristic curve and the influence of the leak detection process by the physical environmental factors of temperature, initial vacuum value etc, and to put forward the corresponding improvement measures.(4) Based on the above analysis, we optimize the micro-car air-conditioning piping leak detection process. It includes filling equipment testing standards and the leak detection process two aspects. Then we propose new monitoring variables, and optimize the vacuum and finish the pressure testing.