超临界直流锅炉蒸汽发生器的建模与仿真研究(二)

Modelling and Simulation Study on a Supercritical Once Through Boiler Steam Generator

本文的第一部分建立了蒸汽发生器的数学模型，并对模型切换、代表参数的选取、二次建模以及超临界压力下汽水区域的划分等问题进行详细讨论，第二部分以此为基础给出仿真实例，并从理论上分析了仿真结果的合理性。

Nonlinear lumped parameter moving boundary model of a supercritical once through 600MW boiler steam generator for large load change or for large scale disturbance simulation is developed in this paper. The problems are solved successfully about subcriticalsupercritical model switching and dry modewet mode (of the medium at waterwall outlet) model switching. The selection problems of representative parameters of each lumped parameter section are investigated. This paper also proposes that the conditions at maximum specific heat point (quasi critical point) could be used as divide criterion between water region and steam region under supercritical pressure. The derivative terms in the right of secondary modelling equations are eliminated by proper mathematical processing, therefore, the stability of numerical integration is improved. Three groups of simulation examples are presented in the final part of this paper, and theoretical analysis shows that the simulation results are reasonable.