Enthalpy and Exergy Transfers of High Pressure Switching Expansion Reduction  

作　　者：罗语溪 王宣银 雷军波 

机构地区：[1]State Key Laboratory of Fluid Power Transmission and Control,Zhejiang University

出　　处：《Journal of Shanghai Jiaotong university(Science)》2012年第1期45-52,共8页上海交通大学学报（英文版）

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

摘　　要：The energy balance, air internal energy, enthalpy and exergy transfers of high pressure switching expansion reduction （SER） are comparatively analyzed in this paper to give a better understanding about the exergy analysis and its difference between energy conversion analyses for the pneumatics. In SER, the exergy transfer efficiency is much lower than the enthalpy efficiency. The enthalpy efficiency is primarily related to the initial pressure of supply tanks, and the exergy efficiency is primarily related to the pressure reduction ratios. Heat transfers increase the internal energy, enthalpy and exergy of air; the influence on exergy is relatively small. The total enthalpy in SER decreases as the air temperature decreases in the expansion process of the air. And exergy loss is primarily related to the irreversible process of isenthalpic throttling but not energy conversion. Based on the analyses, to improve the exergy efficiency of the pneumatics, the pressure reduction without power output should be avoided.The energy balance,air internal energy,enthalpy and exergy transfers of high pressure switching expansion reduction(SER)are comparatively analyzed in this paper to give a better understanding about the exergy analysis and its difference between energy conversion analyses for the pneumatics.In SER,the exergy transfer effciency is much lower than the enthalpy effciency.The enthalpy effciency is primarily related to the initial pressure of supply tanks,and the exergy effciency is primarily related to the pressure reduction ratios.Heat transfers increase the internal energy,enthalpy and exergy of air;the influence on exergy is relatively small.The total enthalpy in SER decreases as the air temperature decreases in the expansion process of the air.And exergy loss is primarily related to the irreversible process of isenthalpic throttling but not energy conversion.Based on the analyses,to improve the exergy effciency of the pneumatics,the pressure reduction without power output should be avoided.

关 键 词：ENTHALPY EXERGY energy balance effciency pressure reduction 

分 类 号：TP271.3[自动化与计算机技术—检测技术与自动化装置]