The shaft seal heater is a heat exchange device in a steam turbine, which plays an important role to the performance of the shaft seal system. Based on limited data, a method for calculating the relevant parameters of the shaft seal heater was proposed by using an iterative algorithm. The algorithm was validated by comparing the calculated basic heat transfer parameters of the shaft seal heater with the results from Aspen Plus software. The discrepancy is within 0.4%, which validates the iterative algorithm presented in this paper. Taking the practical application of the combined cycle steam turbine unit of Huaneng Beijing Thermal Power Co., Ltd. as an example, the liquid phase and gas phase flow at the outlet of the shell side, under the condtion of inlet parameter change, were calculated by using this method. Moreover, the correlation model between the fluctuation of import parameters and the heat transfer parameters of the heater was established to verify the effectiveness of the method.
