基于炉内三维燃烧检测的蒸发系统分布参数建模

利用炉内三维燃烧工况实时可视化检测系统获得的炉内烟气三维温度分布及炉膛辐射能信号,计算炉内水冷壁二维表面非均匀辐射热流分布。以此作为边界条件,建立锅炉蒸发系统分布参数动态模型,反映壁面热流密度、壁面温度、质量含汽率、质量流速等热力参数在蒸发受热面上的动态分布,以及汽包压力、水位、出口蒸汽流量的动态变化。对模型中与对象有关的两个主要参数——汽包出口流量方程系数和炉内烟气等效射线长度,进行了辨识计算,以适应大范围负荷变化的需要。

Distributed-parameter Modeling of Evaporation System Based on Three-dimensional Combustion Monitoring in Furnace

The non-uniformly distribution of two-dimensional radiation flux on the surfaces of water-cooled tubes in a furnace is obtained through the three-dimensional temperature distribution and the furnace radiation energy signals which are got by a real-time visualization monitoring system for the three-dimensional combustion.By the radiation flux distribution taken as the boundary condition,a dynamic,parameter-distribution model for the evaporation system is established,which can give the dynamic distributions of the wall heat flux,wall temperature,mass fraction of steam and mass velocity outside/inside the evaporation system,and the dynamic variations of drum pressure,drum level and steam mass flow rate in the outlet of the system.Two important parameters in the model,the coefficient of mass flow equation in the outlet of the drum and the equivalent ray length of the flue gas inside furnace,are estimated in order to meet the requirement for the large-range change of boiler load.