Study On Dynamic Performance And Water Level Control Of Marine Steam Generator

Steam generator is one of the core devices of nuclear power plant.Its dynamic performance directly affects the dynamic operation of the entire nuclear power plant.The water level of steam generator is one of the important parameters during its operation.If the water level is too low,the heat transfer will be deteriorated,in severe cases may cause heat transfer tube rupture.If the water level is too high,the water content at the outlet will be too high and the steam turbine blade will be eroded,even hazard to the unit.When the second loop system of nuclear power greatly reduces the load or in accident conditions,the steam in the steam generator needs to be discharged to the main condenser through the desuperheating and reducing device,to reduce the transient change of the primary loop and prevent the steam generator from overpressure.Therefore,it is of definite engineering practical significance to research the dynamic performance,water level control and steam discharge of steam generator.This paper uses the method of modular modeling,a dynamic simulation model of steam generator is established based on the GSE simulation platform,and the model is verified through the design parameters.On this basis,the dynamic performance of the steam generator and the steam generator water level control strategies were simulated and analyzed under different disturbances and load conditions,and the simulation of steam emission control under accident conditions was also studied.Through simulation experiments,it can be seen that when the feed water flow step is reduced by 15%,the steam generator water level stability is 0.434.When feed water flow step decreases,may cause the danger that the water level of steam generator being too low.The step reduction of the feed water temperature affects the economics of the steam generator operation.The feed water temperature is step reduced by 15%,cause that steam production is reduced by 1.94%.The steam generator dynamic simulation model was simulated with 15% power reduction to study the dynamic performance of the steam generator in the condition of the load was reduced.Not only under high load conditions or under low load conditions,but also in response to water level set point,load disturbance,disturbance of feed water flow,cascade feedforward control has small overshoot,low stable time,excellent dynamic performance,is an ideal control method for water level control of steam generator.During emergency shutdown,the combination of steam emissions and atmospheric emissions can effectively prevent the primary steam temperature rising to prevent the main steam safety valve from opening.When the main engine shuts off,the steam discharge can relieve the power mismatch between the first and second loops and reduce the transient change of the primary loop..The rapid response of steam emission can effectively prevent the overpressure of the first and second loops and maintain the balance between the power consumed by the second loop device and the power of the reactor.