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本文叙述了以区域法计算辐射传热的数学模型。在区域法中,系统被分为表面区和气体区,区域数取决于所要求的结果精度和计算时间。炉子的温度分布可通过解每区的能量平衡而得。作为Hottel和Cohen的原始开发,直接交换面积限于立方体和正方形;本文给出了在方箱炉、圆筒炉中任何两区之间直接交换面积方程式的推导。这些方程式可适用于任何大小的矩形、共轴圆筒壁、炉底环形区和其他形状。 本文提供了一个关于烃类一段蒸汽转化炉和圆筒炉的设计方法。计及反应动力学、对流传热、管内压降,采用区域法计算这些炉子的温度分布,从而预言工艺气、烟气、管表面和耐火墙表面的温度分布。计算结果与工厂实测数据相吻合。
This article describes the mathematical model of radiative heat transfer calculated by the area method. In the regional law, the system is divided into the surface area and the gas area, the number of areas depends on the required accuracy of the results and calculation time. The temperature distribution of the furnace can be obtained by solving the energy balance of each zone. As originally developed by Hottel and Cohen, the direct exchange area is limited to cubes and squares; this article gives the derivation of the area equation for direct exchange between any two zones in a square box or cylinder furnace. These equations apply to rectangles of any size, coaxial cylinder walls, hearth rings, and other shapes. This article provides a design methodology for a hydrocarbon reformer and a cylindrical furnace. Taking into account the reaction kinetics, convection heat transfer, and pressure drop in the tube, the temperature distribution of these furnaces is calculated by the zone method to predict the temperature distribution on the process gas, flue gas, pipe surface and refractory wall. The calculation results are consistent with the measured data of the factory.