Modeling of main steam and two-phase heat exchanger for nuclear power unit

A detailed nonlinear model for a typical PWR secondary system is developed for the development of simulation software. Each component in the system has been represented by appropriate differential or algebraic equations. The effects of compressible steam flows, non-equilibrium two-phase heat exchange and the characteristics of initial parameters and volume flow rate of PWR nuclear power unit are considered. A fluid flow network package was used for solving nonlinear equations to simulate steady-state and transient operational conditions. Overall system has been constructed by connecting individual components to each other. The validity of models for individual components and overall system has been verified. The simulation result shows that the model can get high accuracy and reasonable transient behavior of the secondary system and can be used for full scope, normal operation conditions and abnormal accident events in real time simulation for PWR nuclear power unit.