Noise Analysis And Experimental Study Of The Swash Plate Compressor For Automotive Air Conditioner

With the constant development of society,people's living standards improve gradually.People pay more attention to the quality of life.As a common means of transport,vehicle's ride comfort for passengers has received more and more attention.An important issue to improve the ride comfort is improving the environment in the car,such as regulating the temperature and humidity.The main solution is to install air conditioners in the car.However,noise was brought after the installation of air conditioners,which is contrary to another important research topic in improving ride comfort of vehicle in order to reduce the influence of the noise caused by the installation of air-conditioning,we must try to reduce air conditioning system noise.The main noise source of air conditioning system is compressor noise.Form of exercise for the compressor compressed the low-temperature and low-pressure refrigerant gas which it sucked into its own internal as high temperature and high pressure refrigerant gas.The main noises generated by the compressor are mechanical noise and aerodynamic noise,and the aerodynamic noise of the intake and exhaust noise is most prominent.In the early study of compressor,people mainly consider raising the cooling capacity of automobile air-conditioning and ignore the study of compressor noise.With the outstanding value of the compressor noise,people began to study it with experiment ways,which requires a longer study period,and requires a lot of manpower and material resources.The emergence of computational fluid dynamics can greatly shorten the research cycle,and lower research costs.In this thesis the author make a deep research in the noise generated by common swash plate air conditioning compressor.Firstly.The structure and working principle of the swash plate air conditioning compressor are introduced in this paper.And on this basis,generation mechanism and control theory of compressor noise are also introduced.Intake and exhaust noise is identified as the main noise source of compressor.Optimizing intake and exhaust noise of compressor can reduce compressor noise.Secondly,the cavity geometry of the compressor is set up.Then the relevant module is applied in hypermesh,which corresponds to the Fluent software,established the calculation volume element model of compressor.The mesh model is imported into Fluent to do the simulation analysis and calculation,which obtains the noise chart of compressor cavity model.Based on this model,the displacement of compressor(compressor refrigerating capacity)is considered fully not to be changed,which working rev of compressor is not changed and the compressor body section structure is changed a little.And in the end,considering the factors of cost,feasibility and validity,three schemes that may reduce the compressor noise are proposed to do simulation analysis and calculation.The optimal scheme is determined and primary and secondary order of these parameters are analyzed by comparing the noise reduction effect of these schemes and using orthogonal optimization test method.Then the noise of compressor cavity model dropped greatly under the best scheme(9.4dB),and optimization is got a satisfactory result.This study provides the feasible methods and thoughts for the noise reduction design of compressor in the future.Finally,a prototype was trial-produced,which was studied experimentally.The optimal scheme is identified as valid by the results of bench tests and vehicle tests.And compressor noise has been effectively controlled.