中文摘要：

根据拟临界温度的定义,结合IAPWS-IF97水物性公式,迭代计算获得了不同压力下的拟临界温度数据,在此基础上拟合出拟临界温度与压力的关系式.基于该关系式计算构建了拟临界温度计算模块,用于热工水力系统程序的跨临界计算改造.应用修改后的热工水力系统程序,针对简单的模型进行了跨临界瞬态计算.结果表明,拟临界温度与压力拟合关系式能够用于超临界压力系统的跨临界瞬态计算.

英文摘要：

The development of thermal-hydraulic system code applicable for transcritical transients＇ calculation requires the support of a pseudo-critical temperature calculating module with high precision.Based on the accurate data of pseudo-critical temperatures obtained by the IAPWS-IF97 thermal-physical property equations, the relation between pseudo-critical temperature and pressure was fitted.The fitting equations are capable of providing pseudo-critical temperatures with good precision.This paper presented the implementation of the fitting equations into a thermal-hydraulic system code,as well as simulation of some simple transcritical transients.The results indicate that the pseudo-critical temperature calculating method developed in this paper is applicable.