Mathematical Modeling And Experimental Investigation For Electric Scroll Compressor

Electric vehicle has the advantages of low noise,zero emission and high economy,and has great potential for development in the future.As an important part of the electric vehicle,the heat pump air conditioning system can adjust the temperature in the cockpit and provide a comfortable driving environment for the personnel in the vehicle.Electric vehicles have the problem of high energy consumption at low temperature,which seriously restricts the application of heat pump air conditioning system in electric vehicles,so it is necessary to study the optimization of heat pump air conditioning system.As the core component of the heat pump air conditioning system,the performance of the electric scroll compressor directly affects the performance of the whole heat pump air conditioning system.In this paper,starting with the mathematical model of electric scroll compressor,the geometric model,leakage and heat transfer model are established,and the correctness of the mathematical model is verified by experiments.The main research contents are as follows:(1)Firstly,according to the meshing principle of plane curve,the composition principle and judgment of scroll compressor profile are discussed,and the profile equation of scroll disk of electric scroll compressor is deduced according to the meshing principle of scroll profile.The composition principle of scroll disk is introduced;Then the double arc correction at the beginning of the scroll disk is described,and the geometric model of the scroll compressor is established;Finally,based on the circular involute theory,the formulas of suction cavity,compression cavity and exhaust cavity are derived,which lays a foundation for the solution of thermodynamic model.(2)Based on the working principle of electric scroll compressor,the dynamic model is established.The tangential gas force,radial gas force and axial gas force acting on the moving scroll disk of the electric scroll compressor are studied,and the variation of these three kinds of gas forces with the rotation of the spindle is studied.Introduces the sealing method of installing a sealing strip on the top of the scroll disk to realize the axial seal and the radial dynamic seal through the lubricating oil.(3)The thermodynamic process of the mixture in the working cavity is analyzed by using the first law of thermodynamics and mass conservation equation,and a perfect thermodynamic model is established.After the established model is programmed with Matlab,the thermodynamic model is solved by Euler algorithm.Considering the influence of heat transfer and leakage on the performance of the scroll compressor,the temperature and pressure of the mixture in the working chamber of the compressor under comprehensive working conditions are studied.(4)According to the mathematical model of the electric scroll compressor,the performance test platform is set up to verify the mathematical model.Under certain working conditions,the variation of temperature,refrigerating capacity,power and coefficient of performance(COP)of refrigerant with spindle speed was tested.The test results show that the theoretical simulation is close to the experimental data and can be used to predict the performance of the electric scroll compressor.