| The new generation of scroll compressors,known as"ultra static","new revolution",and"maintenance free",can achieve advantages such as high speed,stability,low vibration,and high volumetric efficiency during operation,and are widely used in industrial fields such as air conditioning,heat pumps,and refrigeration.When designing a large compression ratio scroll compressor in a refrigeration system,using a traditional single profile or a combined profile composed of different involutes can reduce the volume and production efficiency of the scroll;The combined profile scroll disk composed of a single involute can meet the performance requirements of high pressure ratio,low leakage,and high efficiency.Therefore,this paper designs a new type of three-segment circular involute CP1-2（R1 circular involute+R2 circular involute+R1 circular involute）combined profile scroll disk,and analyzes and compares its comprehensive performance.The main research contents and conclusions of the paper are as follows:（1）Design and geometric characteristics mathematical model establishment of CP1-2combined profile scroll plate.According to the design conditions of the refrigeration system in a small cold storage,the generatrix equation of the CP1-2 combined profile is established based on the circular involute theory.The mathematical model of the inner and outer walls of the CP1-2 combined profile scroll disk is established using the normal isometric method.The spiral tooth end of the CP1-2 combined profile is corrected using the double circular arc（PMP）profile correction theory.A three-dimensional model of the CP1-2 combined profile scroll disk is established using an auxiliary design software,A mathematical model for calculating the dynamic volume and leakage line length of the working cavity of the CP1-2combined profile is derived and quantitatively solved.（2）Analysis of transient flow characteristics in the working cavity of CP1-2 combined profile.Using computational fluid dynamics（CFD）dynamic grid technology,the influence of tangential leakage caused by radial clearance on the transient flow field distribution in the working cavity of CP1-2 combined profile was studied in the three-dimensional fluid domain.The research results show that tangential leakage has a small impact on the uneven distribution of pressure in the working chamber,but it has a significant impact on the uneven distribution of temperature in the same and adjacent working chambers,and there is an extreme value of velocity at the meshing gap.（3）The effect of combined profile construction on the performance of a scroll compressor.".Ensure that the starting angle of the bus is the same before and after the replacement,and change the construction method of the combined profile line establish a two-stage circular involute combined profile CP1-3（R1 circular involute+R3 circular involute）and CP2-3(R1 circular involute+R3/2 circular involute)scroll disk,compare and analyze the performance differences of the combined profile scroll compressor with different construction methods,and select the optimal circular involute combined profile structure.The research results make known that compared to the CP1-3 and CP2-3 combined profiles,the CP1-2 combined profile scroll compressor has the best overall performance,with a pressure ratio increase of 29%and 8%,and an indicated work increase of 54.31%and15.86%,respectively,with the highest work efficiency;The maximum volumetric efficiency of the CP1-2 combined profile scroll compressor is 93.17%and reaches the first level energy efficiency standard,with an energy efficiency ratio of 4.95.（4）Comparison of linear performance between CP1-2 combined profile and single circular involute profile.Based on the control variable method,a single profile scroll plate was introduced to compare and analyze the performance differences of scroll compressors with different profile types,and the optimal performance of the CP1-2 combined profile type was discussed and verified.The research results show that compared to a single profile,the pressure difference and temperature difference between the adjacent and symmetric high-pressure chambers of the CP1-2 composite profile both decrease,resulting in a decrease in various gas forces and moments on the scroll plate of the CP1-2 composite profile.Therefore,its indicated power is increased by 15.13%,and the leakage in the working chamber is reduced by 78.05%.Figure[53]table[23]reference[69]... |
