Abstract: 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.

Key words:  supercritical water, transcritical transients&rsquo, calculation, properties of water, pseudocritical temperature