直流锅炉蒸汽发生器的模块化建模与仿真

Modular Modeling and Simulation of Once-through Boiler Steam Generator

为简便、全面地研究直流锅炉蒸汽发生器的动态特性,采用了模块化和移动边界法相结合的方法,建立了直流锅炉蒸汽发生器的数学模型。建模过程中,将蒸汽发生器划分为水冷壁、汽水分离器两大模块,其中水冷壁分为三段,采用非线性集总参数移动边界法建立三个独立模块;汽水分离器采用集总参数法建立干式运行模块。在仿真模型的基础上进行动态仿真试验,试验结果与实际系统的动态特性相符,不仅成功解决了大扰动全工况仿真问题,而且使得二次建模过程更为简便。该模型的建立,为直流锅炉系统工程分析和大规模火电厂仿真机的开发打下了良好的基础。

To make the study of character ristics simpler and more comprehensive, a general mathematical model of once - through boiler steam generator is created by the method of modular modeling and moving - boundary. In the course of the modeling, the steam generator is divided into water - cooled wall and steam separator. The module of water - cooled wall mainly includes three modules, which are created by the method of nonlinear lumped - parameter moving - boundary ; the model of steam - water separator is created by the method of lumped - parameter, based on the dry running condition. The corresponding dynamic simulation experiments are carried out. The simulation results show that it possesses coincident dynamic characteristics of actual systems. It not only solves the problem of large load changing or large scale disturbance simulation, but also makes the secondary modeling simpler. The establishment of this model provides a considerable groundwork for the engineering analysis of the once - through boiler system and the simulator development of the large - scale thermal power plant.