Research On Modeling And Simulation Of Main Steam System Of The Nuclear Power Plant

The passive safety nuclear power technology has been widely accepted at home and abroad because of its safety and economy.The system structure and operation characteristics of large passive nuclear power plants are very different from the existing nuclear power plants.To provide reference to design work for passive nuclear power plant and train operating personnel,simulation research on passive nuclear power plant need to be carried out.Full scope simulators of nuclear power plants have been developed.But for the passive safety nuclear power plant,most of the simulation research work is about main coolant system and passive safety system,very little has been done to study on simulation of conventional island.The main steam system is an important system of conventional island,the developed simulation model of the main steam system has a certain reference value for the system design and operation personnel training.In this paper,the passive safety nuclear power plant main steam system simulation model is built by using the two-phase flow graphical modeling tool of JTopmeret.The scope of simulation ranges from the steam generator outlet to the low pressure steam turbine exhaust,including the main steam turbine system,moisture separator reheater system,steam turbine bypass system and drainage system.The steam turbine speed calculation module and speed control module are developed using FORTRAN programing language,and involved in the calculation after connected to the JTopmeret generated modules.On this basis,the simulation model of main steam system and other systems are connected to form a passive nuclear power plant full scope simulation model.In addition,the main steam system man-machine interface is designed by using the interface design tool JDesigner,so the important parameters of the system can be monitored easily.In order to validate the rationality of the simulation model,the steady-state full power test is carried out firstly.Simulation results show the accuracy of the main parameters meet the requirements.Then,the results of the transient state test of raising power linearly from 90% full load to 100% full load and reducing power sharply from 100% full load to 96.5% full load show the change trends of some important parameters are reasonable.Finally,two system malfunctions of the second stage reheat extraction line break and the first stage reheat tube leak are chosen to test the model.The test results show the responses of key parameters accord with physical lows.The steady-state,transient state and malfunctions tests prove the reasonability of the simulation model.The main steam system simulation model established in this paper is a part of the simulation model of the passive safety nuclear power plant.The work is mainly used to verify the digital instrument and control system,and also lay the foundation for the research and development of the full scope simulator of the passive safety nuclear plant.