临界点附近H2气体的焓和熵的热力学计算

采用热力学方法和Benedict-Webb-Rubin(BWR)方程及相应的参数,计 算了临界温度附近H2气体的绝对焓和熵值,同时拟合了一组高准确度的定压比热容与温度 关联式参数.通过计算值与实验值的比较发现:在临界温度以上,计算值与实验值符合良好 ,对低于临界温度的未饱和H2气体也能计算出较好了结果.但对临界点和温度低于临界温 度、压强高于临界压强的过饱和H2气体的计算误差比较大,说明此时的H2气体的热力学性质特别,应当专门处理.

A thermodynamics caculation of specific enthalpy and entropy for gas H2 near the critical state

The specific enthlpy and entropy for gas H 2 near the critical temperature (T c) has been calculated by using thermodynamics method and Benedict-Webb-Rubin(BWR) equation as well as the corresponding parameters. The parameters for the relationship equation between specific thermal capacity and temperature are also deduced. Comparing the calculation results with the experimental counterparts, one can find that the theoretical results are in good agreement with the experimental data when the system temperature is up T c or under T c but the pressure not higher than the critical pressure (P c). For the gas H 2 under T c and higher than P c, the errores between the calculated results and experimental values are obvious. It shows that gas H 2 in the condition has especial properties, which implies special treat is necessary.