Study On The Comprehensive Performance Of Variable-wall Scroll Combined By IHC Profile

Scroll compressor is a new type of positive displacement compressor,which is widely used in the automobile,air conditioning,food and drug industry,refrigeration and other fields because of its compact structure,energy saving and environmental protection,high efficiency and low noise.Scroll plate is the core component of the scroll compressor,and its structure and parameters of scroll profile are very important to the performance of the compressor.Due to the small number of turns and high efficiency,the combined scroll profile has become a research hotspot.Therefore,it is of great significance to research the geometrical design theory and mechanical properties of high-order curve combined profile for improving the comprehensive performance of a compressor.This dissertation is divided into the following four aspects:(1)Theoretical research on the construction of IHC(involute-high order curve-circular arc)combined profile.Firstly,aiming at the problems of less range and flexibility of the available profile,the first eight characteristic operators of high-order curve were proposed as the research object to code and combine them.Then the new IHC profiles were obtained.Secondly,the condition of whether the new curves could be applied in the scroll profile was studied,and the concept of threshold was proposed as the basis of judging whether the new curve can be used in the scroll profile.Finally,16 IHC combined profiles were obtained by threshold screening,which enriches the optional profiles and improves the design flexibility.(2)The geometric model and mechanical model of the scroll plate were built.Firstly,the geometric model of IHC scroll plate was established by using the method of equidistance and the volume of its compression chamber was calculated.Secondly,the properties of suction volume,discharge volume,compression ratio and the gas force in the working process of the scroll plate corresponding to the profile were studied by MATLAB programming.The influence rule of the characteristic operator of IHC profile on the comprehensive performance of scroll plate was obtained: NO.0123 scroll plate had the largest force but the best geometric performance,while NO.3456 scroll plate had the smallest force but the worst geometric performance;the characteristic operator mainly affects the geometric performance and radial gas force of scroll plate;the more forward characteristic the greater impact of operators on performance.(3)The comparative study of IHI(involute-high order curve-involute)profile,IHC profile and circular involute models.In order to quantitatively compare the advantages of variable wall thickness scroll plate with equal wall thickness scroll plate and to compare the performance of the same type of combined type scroll,the models of IHI scroll plate and circular involute scroll plate were constructed.The performance of three types of scroll plates was compared under the same compression ratio and the same size.Firstly,the volume of suction and exhaust of IHC scroll plate was 14.42%,9.28% larger than IHI scroll plate,45.98%,27.46% larger than equal wall thickness scroll plate under the same size.Secondly,the number of IHC profile turns was 0.4 circle less than IHI profile,1.14 circle less than involute under the same compression ratio.Besides,the mechanical properties of IHC scroll were better.So the IHC profile is more suitable for the scroll compressor.This provides a quantitative basis for the designer when they choosing the type of combined profile.(4)Experiment of manufacturing and performance test of scroll plate.The processing method and track of IHC scroll profile were determined,and the performance of the scroll was tested.Through the analysis of the experimental results of the exhaust volume,exhaust temperature and volume efficiency of the two scroll plates,it was shown that the IHC profile has excellent performance.Among them,the exhaust volume and temperature of the NO.0123 scroll plate was slightly higher than NO.3456 scroll plate,and the volume efficiency of two plates were similar.The results were consistent with the change rule of the geometric performance of the scroll simulated by MATLAB,which verifies the correctness of the model.