Research On Leakage And Flow Field Of Scroll Compressor Based On Dynamic Scroll Rotation

Scroll compressor has the advantages of simple structure,stable operation,high compression performance,low noise and so on.It is widely used in petrochemical industry,food machinery,medical machinery,new energy and other fields.Due to the dimension error of scroll compressor parts during processing and manufacturing,friction and wear between parts,as well as the clearance of the motion pair during installation and other reasons,leading to the rotation of the compressed scroll disk,the asymmetry of the compressor chamber,causing the change of the leakage of the working medium of the compressor chamber.Therefore,the research on the influence of scroll rotation on the leakage and flow field of scroll compressor provides a theoretical basis for determining the reasonable clearance and fitting tolerance of the moving pair.In this paper,based on the geometry theory of scroll compressors,combined with the knowledge of hydromechanics and engineering thermodynamics,the leakage of each compression chamber when the scroll rotates is calculated.Using computational fluid mechanics software,the pressure field and velocity field of each compressor chamber under different rotation angles were simulated,analyzed and compared,and the influence of scroll rotation on the leakage and flow field of the compressor chamber was investigated.The specific research work is as follows:(1)Based on the theory of profile meshing and profile geometry,the profile equation of scroll tooth,the calculation formula of radial leakage line length of axial clearance and the relation of radial meshing clearance with self-rotation Angle were deduced.Aiming at the volume asymmetry on both sides of the scroll compression chamber caused by the rotation of the dynamic scroll disk,the scroll compressor compression chamber was divided into six separate regions(the third compression chamber A and B side,the second compression chamber A and B side,the central compression chamber A and B side),and the volume of each region was calculated.Based on the thermodynamic adiabatic theory,the relationship between the temperature,pressure and density of each compression cavity and the rotation Angle of the vortex disk was obtained.(2)The leakage model of scroll compressor is introduced,and the calculation formula of leakage of each model is deduced when the scroll rotates.MATLAB programming software was used to calculate the leakage between adjacent compressors under ideal conditions and when the rotation Angle of the scroll disk was 0.01 rad and0.02 rad respectively.By comparing the calculation results,it can be seen that the rotation of the dynamic scroll disk has A great influence on the circumferential leakage of the radial clearance,and the leakage of the compression chamber side A increases with the rotation Angle of the dynamic scroll disk,while the leakage of the compression chamber side B decreases with the rotation Angle of the dynamic scroll disk.(3)According to the geometric parameters of scroll compressor,the geometric models of the third and second cavity A and B sides were established by using Solid Works software when the rotation Angle of scroll disk was 0.01 rad and 0.02 rad.Then,ICEM was used to carry out mesh division for each model.Finally,FLUENT numerical simulation software was used to obtain the ideal situation,velocity vector field and pressure field cloud of each compression chamber when the rotation Angle of the dynamic scroll disk was 0.01 rad and 0.02 rad.Compared with the simulation results,it can be seen that with the increase of rotation Angle of the rotating scroll,the gas outlet velocity of the B side of the compression chamber increases,and the gas outlet velocity of the A side of the compression chamber decreases.The gas outlet pressure on the B side of the compression chamber decreases,and the gas outlet pressure on the A side of the compression chamber rises.