Simulation Modeling Of Pulverization System In The Power Station And It's Dynamic Characteristics

Nowadays, the thermoelectric generating sets above 300MW have become the main power generation units in coal-fired power plants. Units is gradually complicated, automation lever improved continuously, and the problems of the safe and economic operation become much more prominent. It presents higher requirements about the operation and maintenance of the pulverization system.However, the pulverization system itself is an extremely complicated system: it is a close coupling, multivariable and nonlinear time varying system. At the same time there also exist many uncertain interference factors: the two phase flow of gas-solid transfer and flow in the pipelines and equipments; the wet coal is drying and heat-transfer with the gas, etal. Simulating the actual pulverization system, which can make it more easy and accurate for us to study and analyze the dynamic property of the pulverization system.The simulation modeling of the system, which can exactly reflect the characters and process of the pulverization system are very difficult because of the complexity of the pulverization system itself.Presently, the dynamic response of the simulation model about the ball mill is correct and the quantitative error won't be great~[1] . But it has not been long to use the middle-speed mill and fan mill in thermoelectric generator units in China, and there are still big gaps between the simulation model and the actual behavior.Therefore, the thesis attempts to make modeling and analysis research toward the pulverization system, through which the method and the experience of the simulation modeling are obtained.This thesis is mainly about the simulation application of pulverization system. The contents are mainly about following items:1. Integrated introduction about the pattern of pulverization system in the thermoeletric generating sets is presented for the followed simulation modeling of thesystem.2. Study the foundation theories and practical methods of the fluid network modeling, which are then applied to the modeling of the pressure-flux passage of the pulverization system.3. The mathematic models of the performance parameter and the thermal dynamic calculation of the pulverization system are established.4. The mathematic models of the pulverization system's auxiliary equipment (coal feeder, coal seprator, etal.).5. Variable dynamic simulation models on lumped-paremeter are set up, and their dynamic properties are analyzed as to improve the models' accuracy.6. Based on Simpanel, project the simulation programme and make figure configuration modeling. Then carry on simulation debuggings and simulation experimentions; analyze the result and the dynamic characteristic as to verify the modeling effects.The simulation models are proved to be effectice for high precision, and have been applied to the Xinhua Corporation' simulation system which has already developped many sets of power plant simulators with high appraisement.