Study of Polytropic Exponent Based on High Pressure Switching Expansion Reduction  

作　　者：Xuanyin Wang Yuxi Luo Zhipeng Xu 

机构地区：[1]The State Key Laboratory of Fluid Power Transmission and Control, Zhejiang University, Zhejiang 310027, China [2]College of Metrology and Measurement Engineering, China Jiliang University, Hangzhou 310018, China

出　　处：《Journal of Thermal Science》2011年第5期435-441,共7页热科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No.50575202)

摘　　要：Switching expansion reduction(SER) uses a switch valve to substitute the throttle valve to reduce pressure for high pressure pneumatics.The experiments indicate that the simulation model well predicts the actual characteristics.The heat transfers and polytropic exponents of the air in expansion tank and supply tanks of SER have been studied on the basis of the experiments and the simulation model.Through the mathematical reasoning in this paper,the polytropic exponent can be calculated by the air mass,heat,and work exchanges of the pneumatic container.For the air in a constant volume tank,when the heat-absorption is large enough to raise air temperature in discharging process,the polytropic exponent is less than 1;when the air is experiencing a discharging and heat-releasing process,the polytropic exponent exceeds the specific heat ratio(the value of 1.4).

关 键 词：polytropic exponent high pressure pneumatics heat transfer pressure reduction 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术] TB42[自动化与计算机技术—计算机科学与技术]