The Development Of Coal Blending Optimization System For Multi-coal Combustion

Chinese energy structure which based on coal decided coal-fired power plant must solve the long-term security of raw materials. The factors that coal-fired power plant combusts the single coal impossibly for a long time, which are the limited and uneven distribution of coal resources, transport pressure, increasing of coal price and the policy of nation about that power boiler combusts inferior coal. To improve power plant efficiency and ensure the security, Multi-coal combustion inevitably become a issue which large-scale thermal power plants must address.The combustion of blended coals is an extraordinary complex physical and chemical process. During the combustion of the blended coals, the component coals affect each other, so the blended coals exhibit the different combustion characters from the single coal. Of course there are more factors that can affect the combustion of blended coals than the single coal. Among these factors the ration of the component coals is most important. It always affects the combustion characters of the blended coals, so it should be the first problem to be solved when the blended coals are used in power station.In this thesis, by analyzed the inevitability and significance of coal blending, it introduced the development of coal blending in domestic and international. Through the studies on the basis of adaptability of two sets of 600MW coal-fired unit Power Plant in JinWan ZhuHai, the main coal quality parameters which effect on the boiler combustion were analyzed and evaluated. It also described the characteristics of coal quality parameters and its discriminant index for stable combustion, burning-out, slagging and emission in detail.Secondly, through analysis on additivity of coal quality parameters on the basis of the existing theories, laboratory proofing and mathematical demonstration, we think coal's low heating value( LHV), the volatile of ash free and air-dried, Sulfur content, ash content and ash fusion temperature exhibit the characteristic of linearity on stratified combustion in furnace under specific conditions. In addition, constraints and objective function of coal blending were determined from actual conditions of power station, and establishes a linear mathematical model. A pilot based on the interpolation Optimization was proposed. Then optimum proportion of coal blending was determined by using of exhaustive method and Multi-Objective Fuzzy Decision.Finally, we developed Multi-coal combustion of optimized coal blending system by use of Delphi7.0 and SQL server2005, verified the correctness of system preliminarily, and put forward to improve opinion and measures on system development.