一种确定锅炉沿炉膛宽度方向热负荷分布的方法

电站锅炉在运行过程中,炉膛热负荷分布受燃料类型、燃烧方式、炉膛形状等多种因素的影响。针对炉膛热负荷分布难以准确预测的问题,提出了一种确定超超临界墙式切圆燃烧直流锅炉沿炉膛宽度方向热负荷分布的计算方法,将某一工况下管子出口温度作为已知条件,结合系统结构参数进行水动力计算,建立压降计算模型,研究水冷壁系统的流动特性以及炉膛的传热特性,确定水冷壁系统阻力、压降以及流量分布。根据计算结果得到单根水冷壁管沿炉膛宽度方向的热负荷分布规律,并以此为基础,建立热负荷模型,对另一工况进行计算与分析。计算结果表明,本文所提出的热负荷分布计算方法能够准确反映每根管子总吸热量沿炉膛宽度方向的分布,可以应用于锅炉现场运行的安全性分析。

A Method for Determining the Distribution of Heat Load in the Direction of the Width in the Furnace of Boiler

During the operation of the utility boiler,the heat load distribution in the furnace of boiler is affected by a lot of factors,such as fuel types,combustion mode,furnace shape and so on.Usually,it is very difficult to accurately predict the heat load distribution in the furnace of boiler.This paper introduces a method for determining the heat load distribution in the direction of the width in the furnace of ultra-supercritical once-through boiler.Wall-tangentially combustion is the mian combustion mode of the boiler.The outlet temperature of the pipe under a certain operating condition is considered as a known condition.Combined with structural parameters of the boiler,hydrodynamic calculation of the water wall system is implemented.The pressure drop calculation model is established.The flow characteristics of the water wall system and the heat transfer characteristics of boiler furnace are studied.Then,the resistance,pressure drop and flow of the water wall can be easily determined.According to the results of the hydrodynamic calculation,the heat load distribution in the direction of the width of the water wall is obtained.Based on this calculation,the model of the heat load distribution is established.Then,another condition is calculated and analyzed under this model.The results show that the method for determining the heat load distribution proposed in this paper can accurately reflect the distribution of the total endotherm of each tube along the width of the furnace.The results of the paper can be applied to boiler safety analysis.