Mechanism model and simulation of pressurizer in the pressurized water reactor nuclear power plant

A dynamic two-phase imbalance mechanism model of pressurizer in pressurized water reactor (PWR) nuclear power plant was built based on some reasonable simplifications and basic assumptions. During the detailed reduction, the equations of energy conservation, mass and momentum conservation are used in obtaining a dynamic two-phase imbalance mechanism model. Considering the influence of the spray flow, heater and safety valve, a pressurizer system was also established upon the Star-90 simulation platform by means of module packaging. The two step disturbances of heater power and spray flow rate were used to test model´s dynamic characteristic while the pressurizer was at full running. The simulation results were compared with the original data obtained by a foreign PWR nuclear power plant simulator. The results show that the mechanism model of pressurizer has good dynamic performance and high accuracy.