BWR steam line and turbine model with multiple piping capability

Abstract

A new steam line and turbine model for the prediction of flow transients in main steam supply lines has been developed. The major objectives of the new model are to predict transients in an arbitrary steam line and turbine configuration and to calculate with good accuracy and speed. The model is incorporated in the BISON BWR dynamics program, but it can also be executed as a stand-alone computer code. The steam flow model is based on one-dimensional adiabatic (and optionally isentropic) flow, including spatial acceleration and compressibility effects. In the finite difference form we use the nonconservative form for momentum and energy equation. An implicit time integration scheme is used to eliminate a time-step limitation. The main features of the model are: • - ability to analyse steam single-phase flow transients in any piping network, - models for valves, tees, turbine assembly • - control system interface • - consistent steady-state initialization technique, - restart facility • - time step control algorithm for transient and steady-state solutions. The model has been assessed by comparing numerical results with both analytical solution and experimental data.