不同状态方程计算螺杆膨胀机膨胀过程的比较  

Comparison of the Expansion Process of a Screw Expander as Calculated by Using Various State Equations

作　　者：应振根[1] 唐长亮[2] 马晓丽[1] 

机构地区：[1]衢州学院机械工程学院,浙江衢州324000 [2]中国科学院工程热物理研究所,北京100190

出　　处：《热能动力工程》2015年第1期31-36,160,共6页Journal of Engineering for Thermal Energy and Power

基　　金：浙江省教育厅科研项目(Y201329708)

摘　　要：膨胀过程是螺杆膨胀机工作的基本过程,利用实际气体状态方程来计算该过程可为分析问题带来方便。本研究通过采用计算膨胀过程的一般方法,分别导出了利用RKS方程和BB方程计算膨胀过程的公式,并针对R245fa有机工质在螺杆膨胀机内的膨胀过程,利用RKS方程、BB方程与工质物性计算软件Ref Prop对螺杆膨胀机的膨胀过程进行了计算比较。结果发现,RKS方程和BB方程都有较高的计算精度,计算结果的相对误差均在4%以内,但RKS方程的精度更高,其相对误差比BB方程小1%左右,因此,更适合以R245fa为工质的螺杆膨胀机膨胀过程的计算。The expansion process of a screw expander is the basic one in its operation and to employ the actual gas state equation to calculate this process can facilitate to analyze any problem. A general method for calculating the expansion process was given and the formula for calculating the expansion process were derived by using RKS equation and BB equation respectively and for the expansion process of the organic working medium R245 fa in the screw expander,the RKS equation and BB equation were compared with the working medium physical property calculation software RefP rop and a calculation was also performed. It has been found that both RKS and BB equation have a relatively high calculation precision,however,the RKS equation has an even higher calculation precision and more suitable for calculating the expansion process of a screw expander with R245 fa serving as the working medium.

关 键 词：螺杆膨胀机 膨胀过程 RKS方程 BB方程 

分 类 号：TK123[动力工程及工程热物理—工程热物理]