锅炉炉内传热燃烧过程仿真

为了模拟锅炉炉膛内部的传热、燃烧过程,为电站仿真提供可靠实用的数学模型,以计算辐射传热的区域假想面模型为基础,把锅炉炉膛沿烟气流动方向分区,以炉膛内最为复杂的燃烧器区域的燃烧与辐射传热过程为研究对象,采用分区集总的方法推导出计算真实壁面和假想壁面有效辐射力的表达式以及煤粉燃尽率的计算式,然后将各个分区的燃料质量方程和能量方程联立,求解出炉内的一维温度场,以及各区段水冷壁的吸热量和热流密度。计算结果与其它文献三维模型的预测值以及实测数据非常一致,但由于模型采用了一维简化处理,收敛较快,可以满足电站实时仿真计算的需要。

Simulation for Heat Transfer and Combustion in a Boiler Furnace

A one-dimensional model was developed for the simulation of heat transfer and combustion in a pulverized coal-fired boiler furnace using the zone imaginary plane method (IPM). The furnace was divided into several zones along the flue gas path, and the combustion and radiative heat transfer in the burner and burning-out regions were calculated using a lumped-parameter method in the zones to simplify analysis for those complex procedures. Formulations of effective emissive power for both real surfaces and imaginary planes were derived and also formulations of burn-off rate for pulverized coal were deducted. One-dimensional temperature profile in the furnace was achieved by solving the mass and energy conservation equations in each zone,and then the radiative heat transfer into water walls could be calculated accordingly. The practical simulations by the model were in good agreement with some predictions by other three-dimensional models and some measured data, and could be done in real time due to the simplicity of the model.