Modeling And Simulation Of 600MW Steam Turbine System

At present, average coal consumption of power supply of China's thermal power unit still has a large gap to the developed countries'. Strengthening research on solving energy-saving and emission reduction problems of coal-fired generators has become the key factor to keep economic sustainable development in the severe situation of Coal resources increasingly consumption, electricity and coal shortages and environmental pressure increasing. Optimizing operation is one of effective ways to realize energy saving and emission reduction on coal-fired generators. The paper works from the background of the construction of all working conditions simulation model and the research on energy saving optimization operation of unit. It takes 600 MW supercritical unit as research object, after analyzing characteristics of steam turbine system, the steam turbine mathematical model is provided using the tool of Matlab/Simulink, along with a hierarchical modeling complex system approach. The paper emphatically presents the modeling of condenser system, deaerator system and regenerative system. And it lucubrates the optimum vacuum of condenser and the piecewise model of deaerator.The paper presents the mathematical modeling of condenser system, And this model has comprehensively considered the coupling influence of many parameters on the optimum vacuum, including circulating cooling water temperature, cooling water flow, vacuum pump output, condenser cleanness, and makeup water. The research shows that the net power of the unit should be calculated with the consideration of the change of vacuum pump output in order to get the more practical optimum circulating water flow. The cleanness of heat transfer surface has great influence on the optimum circulating water flow. We should estimate the cleanness of heat transfer surface in operation to arrange the suitable cleaning interval time,According to the structure and oxygen characteristics of in- built deaerator, this paper proposes the modeling thoughts that the deaerator should be divided into spray oxygen stage, convection heat transfer stage, mixed bubbling phase three sections in according with the steam flowing in the process. We also establish the not piecewise model of deaerator, and according to the analysis and comparison of two models error, the piecewise model not only has higher accuracy and stability, but also can be characterized deaerator internal condensation water state. It created a condition for the thorough analysis of deaerator's thermal properties.Comprehensive consideration of the heater leakage, high water level fault working condition and generality factors, the paper established heater simulation model which can be combined heat transfer section, according to the energy conservation and mass conservation. The feasibility of the model is validated by comparing the simulation results with design datum under different conditions.On the basis of above models, we construct the simulation model of the steam turbine of a 600MW supercritical unit. The correctness and accuracy are validated by comparing the simulation results with design datum under different conditions and operation datum.The work of this paper is one of the important parts of the simulation model of a coal-fired power plant on all working conditions. It has provided a foundation for constructing the whole factory simulation model, the research on the characteristics of off-design conditions energy consumption and the realization of energy saving optimization operation.