Model development and simulation of transient behavior of helium turbine system

This paper describes a performance model for the transient analysis of helium turbine system. Governing equations have been derived from integral forms of unsteady basic conservation equations. The one-dimensional model is employed for flow-paths except turbine and compressor, which are considered as zero-dimensional components and volume-less treatment is employed. Component mathematical model results in a set of ordinary differential equations and algebraic equations. The simulation code is established on MATLAB, and the ordinary differential equations are solved a variable order solver of MATLAB, ode15s. The accidents of loss of load and loss of feedwater to precooler and intercooler, the transients of recuperator and the decreasing heat transfer capacity of intermediate heat exchanger are simulated respectively. The analysis of calculated results verifies the present model. The effects of bypass valve size and thermal inertia of the recuperator wall are also studied. The simulation results show that throttle size of bypass valve has important influence on the characteristics of turbine system and should be carefully selected to satisfy the requirement of system control and safety.