Models for Entropy Analysis of Single-Phase Heated Surface under Transient Condition and Analysis on Its Contrast with That of Steady Condition

The aim is to describe the irreversibility of energy system under transient conditions scientifically and analyze the further dynamic reasons. Models for entropy distribution under transient conditions are established and applied to reheater of a 1913t/h-boiler. The results show that some error occurs when model for steady conditions are used for transient conditions. The main reason is that the heat stored in metal and the time rate of entropy are ignored.