Structure Optimization And Experiment Study Of Scroll Expander

Micro-compressed air energy storage system plays an important role in peak-shaving,frequency regulation and improving reliability of power grid due to its characteristics of non-pollution and small phase change loss.As an important part of the system,the efficiency of the expander is the key to improving the energy conversion efficiency of the system.In this paper,the scroll expander is studied.Increasing the exergy efficiency of the expander is used as target.The working process and intake resistance of the scroll expander are analyzed in detail.The scroll disk structure is optimized and tested to improve the exergy efficiency of the expander.And the intake resistance is reduced.At first,the working principle of the scroll expander is analyzed in this paper.On this basis,the cutting angle at the beginning of the intake chamber and the inlet size are considered.And the mathematical model of the relationship between the cutting angle of the air intake chamber,the size of the inlet and the exergy efficiency are built.Using the MATLAB/Simulink mathematical analysis software,the working process of the scroll expander is analyzed.The working mechanism of the expander is fully analyzed in detail.The curve of the exergy efficiency of the expander with the change of the inlet pressure is obtained;Using MATLAB/Simulink numerical analysis and FLUENT 14.5 numerical simulation software,the performance curve of the expander's exergy efficiency changing with the cutting angle at the beginning of the intake chamber and the flow field distribution of the expander are obtained,under the condition that inlet size remains unchanged.And the curve of the expander's exergy efficiency changing with the inlet size and the flow field distribution of the expander are obtained when the the cutting angle at the beginning of the intake chamber is constant.Based on the comprehensive analysis and simulation results,according to the specific inlet pressure conditions,In order to increase the exergy efficiency,the structure optimization scheme of scroll disk is designed.Scroll disk is processed.Experiment platform is built.And the change trends of exergy efficiency at the different cutting angles of intake chamber and the different inlet sizes are experiment studied.Experiment results show:The exergy efficiency increases with the expansion of inlet sizes.Under different inlet pressures,the optimal cutting angles of the inlet head of the scroll disk are different.At last,the optimal schemes of scroll expander under different inlet pressure are tested.It is proved that the optimization scheme designed in this paper is effective for improving the exergy efficiency of the scroll expander,and has practical significance.