Research On The Influence Of The Geometric Parameters Of Double Wraps Scroll On Its Performance

As a new generation of positive displacement compressor,double wraps scroll compressors are widely used in all walks of life due to their advantages of low vibration,low noise and large suction capacity.With the continuous improvement of market demand,the design work of scroll compressors has become more and more refined,and the designer’s control of compressor performance has become more and more strict.In the process of scroll design,there are many sets of scroll geometric parameters that meet the design requirements,but the dynamic performance of the scroll is very different under different geometric parameters,and the stress and deformation of the scroll are also due to the change of the geometric parameters.These changes result in varying degrees of wear on the scroll contact areas.Designers often need several trial calculations to obtain the scroll parameters with better performance.Repeated trial calculations undoubtedly increase the workload.So it is particularly important to optimize the parameters according to the dynamic performance of scroll to get the geometric parameters of scroll disk with good performance.In this paper,the vertical high-pressure shell-cavity double wraps scroll compressor is taken as the research object,and a geometric model of the orbiting scroll diameter of the double wraps scroll compressor is established based on the particle swarm algorithm.The influence of the basic geometric parameters of the scroll on the diameter and pressure ratio of the orbiting scroll is analyzed.Based on the standard particle swarm optimization model,an optimization program was written to obtain the parameter values of the vortex disk after one optimization.Combined with engineering experience,the geometric parameters of the scroll are optimized twice,and the centrifugal inertia force,axial gas force,radial gas force,tangential gas force and overturning moment of the scroll under the parameters before and after optimization are compared and analyzed.In addition,the finite element analysis software is used to simulate the stress and deformation of the orbiting scroll under the liquid back pressure cavity,and the stress of the orbiting scroll under the action of temperature load,pressure load and coupling action of temperature load and pressure load is obtained.with deformation.The value of the thickness of the end plate is studied from the perspective of deformation,and the value range of the thickness of the end plate is given.At the same time,the influence of the temperature and pressure of the lubricating oil in the back pressure cavity on the axial deformation of the scroll is compared and analyzed.Finally,combined with the friction and wear mechanism,the friction and wear of the scroll is analyzed from a theoretical point of view.The axial deformation simulation results of the end plate are combined with the theoretical research to predict the position where the scroll end plate wears more.The research shows that with the scroll diameter as the optimization target,the scroll parameter optimization method equipped with the particle swarm algorithm can quickly obtain the parameter values that meet the requirements.The axial gas force and the overturning moment are significantly reduced.Increasing the base circle radius of the double wraps scroll can increase the suction volume of the scroll compressor.Under the same diameter of the orbiting scroll,the suction volume of the double wraps scroll is larger than that of the single scroll.After considering the influence of the pressure and temperature of the lubricating oil in the back pressure cavity on the lower surface of the end plate,the orbiting scroll was simulated.After considering the influence of the pressure and temperature of the lubricating oil in the back pressure cavity on the lower surface of the end plate,the orbiting scroll was simulated,and it was found that the stress value of the orbiting scroll on the edge of the end plate and the root of the scroll tooth under the action of temperature load Larger,the largest deformation is located at the top of the orbiting scroll tooth corresponding to the center position of the stationary scroll.Under the action of pressure load,the maximum stress is located at the root of the orbiting scroll tooth head,and the maximum deformation is at the spiral tooth head between the second compression chamber and the third compression chamber.Under the combined action of temperature load and pressure load,the maximum stress of the orbiting scroll is located at the root of the scroll teeth,and the maximum deformation is at the top of the scroll teeth of the second compression chamber.The comparative analysis shows that the changes of lubricating oil temperature and pressure in the back pressure cavity have little effect on the axial deformation of the movable scroll.The axial deformation of the scroll under different end plate thicknesses is studied,and it is found that the reduction of the scroll axial deformation does not change linearly with the increase of the end plate thickness,and the end plate thickness should be greater than 10 mm under the working conditions of this paper.Based on the friction and wear mechanism,combined with the axial deformation of the scroll,it is predicted that the wear amount of the inner ring on the contact surface of the movable and stationary scroll end plates is larger.