Research on method for modelling and control of feedwater piping system based on internal characteristics of the feedwater pump

Abstract

In this paper, a method for modelling and control of feedwater piping system based on internal characteristics of the feedwater pump is introduced considering the modelling, control and simulation of the feedwater control system. The traditional modelling based on characteristic curves of the feedwater pump can only describe the steady-state characteristics of the feedwater piping system, while the modelling method of feedwater piping system based on the internal characteristics of the feedwater pump can simultaneously simulate both the steady-state and dynamic characteristics of the feedwater piping system, providing a simulation test object for feedwater control system design. A mathematical model of the feedwater piping system based on the internal characteristics of the feedwater pump is created according to the momentum moment theorem and latticed wing analysis theorem. VC++6.0 is applied to develop the simulation program and the Runge-Kutta method is applied for solving the mathematical model. In this paper, we also design the feedwater pump speed control system, apply the scheme of simultaneous control of feedwater regulating valve pressure difference and turbine feedwater pump speed difference, and increase the anti-interference ability of the feedwater pump in parallel operation. The speed control system of the turbine feedwater pump is verified by simulation tests on typical working conditions of the feedwater piping system. Simulation results show that this modelling method can describe the steady-state and dynamic characteristics correctly, with certain significance in engineering application.