Research on dynamic characteristics and influencing factors of steam bypass exhaust condition of marine nuclear power plant

Objectives  Based on the operation requirements of steam bypass exhaust system of marine nuclear power plant, the dynamic characteristics and influencing factors of bypass exhaust conditions are analyzed. Methods  According to the functional characteristics of the steam bypass exhaust system, the mathematical and physical models of the matching operation of the steam generator, steam system, bypass system and main steam turbine are established. The dynamic operation characteristics and the coupling matching characteristics of the primary and secondary circuits under extreme working conditions such as quick closing of the main steam valve and load rejection of the steam turbine are analyzed to verify the accuracy and universality of the simulation model. Results  The simulation results show that when operating under bypass exhaust condition, the appropriate bypass exhaust valve, main steam valve and their matching action time should be selected according to the power self-regulation capacity of the marine reactor, and the safety problems such as overpressure of the steam header and overspeed of the steam turbine unit should be comprehensively considered. At the same time, the steam demand of other equipments on the ship should be met. Conclusions  The research results can provide reference for the safety control of side exhaust conditions and the optimal design of side exhaust system of nuclear power plant.