电站锅炉过热器的集总参数动态建模与仿真

摘要

Traditional superheater models are unable to simulate the operating conditions under large disturbances with high precision. To solve this problem, this paper presented a lumped-arameter dynamic model of power plant boiler' s superheater. The present model described the dynamic processes of the pressure-flowrate and enthalpy-temperature channels with sufficient consideration of their coupling effect. To describe the distributed-parameter property of superheater' s temperature better, the multi-segment lumped-parameter modeling method was employed for modeling the enthalpy-temperature channel. Dynamic responses of the last-stage superheater of a 600 MW controlled circulation boiler to the spray water flowrate, the superheater inlet enthalpy and the quantity of absorbed heat disturbances were simulated. Simulation results show that dynamic responses of the present model are reasonable, and the model has higher precision, which can meet the requirements for full-scale simulation and control system simulation.%研究锅炉过热器优化控制问题,针对传统过热器模型无法对大扰动工况进行高精度仿真的问题,给出了一个电站锅炉过热器的集总参数动态模型.模型描述了过热器压力-流量及焓-温通道的动态过程,并且充分考虑了两个通道间的耦合效应；在焓-温通道建模时,采用了多段集总参数建模的方法,从而更好地反映了过热器温度的分布参数特性.以某600 MW控制循环锅炉末级过热器为对象,对减温水流量、过热器人口蒸汽焓值和吸热量扰动下该模型的动态响应进行了仿真.仿真结果表明,模型动态响应合理、精度较高,可以满足控制系统优化性能的要求.