Development Of The Oil-free Scroll Compressor Machine Of The Fuel Cell System And Optimization Of The Scroll Profiles

Countries around the world are actively seeking solutions to the growing energy and environmental problems.Fuel cell vehicle(FCV)has become the focus of competition among countries.Scroll compressor is one of the first choice of air compressor for cathode air supply system of vehicle fuel cell.It can pressurize the inlet air to improve the power density and efficiency of fuel cell.At present,the domestic oil-free scroll air compressor applied to more than 60 kW has not yet been broken through,so it is of great significance to develop and optimize the vehicle fuel cell scroll air compressor with independent intellectual property rights for reinforcing the short board of key components of vehicle fuel cell system in China.This paper focuses on the development and design of oil-free scroll air compressor for 60 kW fuel cell and the optimization design of the scroll wrap.In this paper,the principle,structure and design theory of oil-free scroll air compressor for fuel cell were introduced.The geometric theory,heat transfer theory and mechanical model of the double scroll air compressor were mainly introduced.The design theory,design process and design details of the fuel cell scroll air compressor were introduced in detail.The PEMFC-SC-60 kW fuel cell air supply oil-free scroll air compressor with single disk and double vortices in parallel was designed by MATLAB,SolidWorks and ADAMS;At the same time,through the establishment of virtual prototype and the assembly design,interference check and dynamic balance design of moving parts through kinematic and dynamic simulation,the motion law of air compressor was verified.In order to carried out the interference prediction and assembly clearance calculation of oilfree scroll air compressor of fuel cell: Firstly,the volume dispersion of each scroll compression chamber in a cycle was calculated,and the initial values of temperature load and pressure load at different spindle angles of the compression chamber were obtained.Secondly,the average temperature field and pressure field of the scroll cycle were acquired by homogenizing heat transfer calculation.The method of obtaining the temperature and pressure field based on the uniform load for the simulation and analysis of the deformation and stress of the scroll tooth was put proposed,and radial segmentation theory of temperature field of scroll plate was put proposed which feasibility was verified by experiment.Finally,the exponential piece-wise temperature formula was proposed as an alternative method to simplify the calculation of temperature field which is more concise and can meet the accuracy requirements.Based on ANSYS finite element method,the deformation and stress field of scroll plate under uniform loads such as temperature,pressure were analyzed.The simulation results show that the maximum stress of the fixed plate is 153.21 MPa,located at the root of beginning end of the scroll wrap;the maximum stress of the orbiting plate is 88.88 MPa,located at the root of end of the scroll wrap;The radial correction value of 70% area of scroll wrap is less than 0.030 mm,the maximum correction value is 0.092 mm,the average value is 0.0239 mm,and the equivalent radial clearance is 0.0339 mm after adding 0.010 mm additional correction value to all mating surfaces;After deformation,there is no interference between the axial mating surface of the orbiting and the fixed plate,and the axial clearance is set to 0.010 mm.