Mathematics Modeling And Simulation Of Steam Water System Of Supercritical Generating Unit Based On Graphic Configuration

Supercritical thermal power generation technology is a very popular technology in energy conversation, environmental protection, increasing generating efficiency and reducing generating cost. So it is very necessary to research the dynamic characteristics of supercritical generating unit for unit operating safely and economically. Technique of simulation of supercritical generating unit is a very good method in research, by which we can find out the dynamic characteristics of generating unit, and which can supply the reference for the optimization and control of generating unit and fault diagnosis of it. Where the simulation is concerned, the biggest difference between the supercritical generating unit and subcritical generating unit is the boiler steam-water system. This thesis discusses the modeling method of the steam-water system of some 600MW supercritical generating unit, constructs its simulation system, and researches its dynamic characteristics by simulation. The main contributions of thesis include as follows:1. The mathematical models of the correlative equipment in the 600MW supercritical generating unit steam-water system are obtained by the three laws of conversation of mass, energy and momentum, including the models of water wall, steam-water separator, heat exchanger, coefficient of heat transfer and so on. The focus is a nonlinear fixed-boundary multi-zone model of the water wall, which avoids the model switching between different modes.2. The steam-water system of supercritical generating unit is a multivariable multi-input and multi-out complex system, this thesis establishes the mathematical model of the systems of boiler, steam turbine and bypath to insure the validity of the simulation.3. In a configuration simulation environment, the simulation modules of the equipment are created by the technique of the modular modeling.4. The simulation system of the steam-water system in the 600MW supercritical generating unit was constructed by means of configuration. And a series of simulation experiments were made, which include start-up simulation, the disturbance of fuel, feed water, and opening angle of high pressure governing valve. The simulation results correctly reflect the dynamic characteristics of the steam-water system, and the static accuracy can meet the demand of the simulation.In a word, this thesis establishes the simulation mathematical models, which are fit for the large disturbance and full scope simulation, and lay the groundwork for future research in the simulation machine of the supercritical generating unit.