Optimal Design Of Helium Xenon Centrifugal Compressor And Experimental System Simulation Research

The closed Brayton cycle is widely used in deep space and deep sea exploration,and it is currently one of the most potential power cycle devices.In deep space and deep sea environments,helium-xenon mixed gas is often used as the circulating working medium of the closed Brayton cycle.Helium in the mixed gas has excellent transport characteristics,and xenon can make the mixed gas easier to compress.The helium-xenon centrifugal compressor is a device for compressing gas in the closed Brayton cycle power system,and it is one of the important parts of the entire cycle system.Existing centrifugal compressor research rarely uses helium-xenon gas as the working medium,lacks relevant design methods and optimization theories,and needs to be further studied.According to the above background,the main research contents of this paper are as follows:Firstly,conduct an in-depth study on the physical properties of the helium-xenon mixed gas.The physical properties of helium-xenon gas at different temperatures,pressures and molar ratios of xenon gas are studied.In this paper,the variation law of physical parameters of helium xenon mixture in the variation range of compressor temperature and pressure is analyzed,and the necessity of considering the variation of physical properties of helium xenon mixture in compressor design is verified.The impeller of helium xenon centrifugal compressor is aerodynamic designed,the design process is optimized considering the change of physical properties of helium xenon gas,and the full flow calculation of helium xenon centrifugal compressor is carried out.Secondly,the effects of the gap size and structure change at the top of the blade on the performance parameters of the centrifugal compressor are deeply studied,the optimization mechanism of the splitter blade structure on the helium xenon centrifugal compressor is analyzed,and the flow characteristics of the helium xenon centrifugal compressor are described.The performance index changes and internal flow field characteristics of helium xenon centrifugal compressor with splitter blades at different lengths and circumferential positions are systematically analyzed,the influence law of splitter blade parameters on performance is summarized,the optimal splitter blade position is obtained,and the flow mechanism in helium xenon centrifugal compressor with different splitter blade lengths and circumferential positions is revealed.Finally,in order to solve the experimental cost problem of helium xenon centrifugal compressor caused by the high price of helium xenon gas,the similarity experimental theory is applied to helium xenon centrifugal compressor to study the feasibility of replacing helium xenon mixture with working medium in helium xenon centrifugal compressor experiment.sing argon and air as the alternative working medium of helium xenon mixture and applying the similarity experimental theory,the flow similarity between the centrifugal impeller with argon and air and the original helium xenon impeller is analyzed,and the performance parameters of the centrifugal compressor under full flow are compared.By building the helium xenon centrifugal compressor experimental system,the changes of the parameters of the main experimental components in the helium xenon centrifugal compressor experiment are studied,and the influence of using argon as the alternative working medium of helium xenon mixture on the original experimental system is also studied.