基于炉气非灰辐射特性的钢坯表面热流研究

Heat Flux to Slab Surface Based on Non-Gray Radiation Properties of Gas in Reheating Furnace

基于加热炉内炉气的非灰辐射特性,指出三元辐射体系(炉气-炉壁-钢坯表面)中炉气存在2种发射率和6种吸收率。应用射线跟踪方法推导钢坯表面热流表达式,解除了Τимофеев公式中炉壁为零热流和炉气为灰体的限制。以某轧钢厂的一座步进梁式加热炉为例,对其钢坯表面热流进行了模拟计算。推导的钢坯表面热流表达式为加热炉在线控制数学模型中钢坯表面热流的简化算法提供了理论依据。此外,给出了炉气为非灰时的辐射全交换面积的一种计算方法,为准确求解加热炉炉膛内的辐射热交换创造了条件。

Based on the non-gray radiation properties of the gas in reheating furnace, two different emissivities and six different absorptivities of the gas in ternary model are distinguished. The heat flux expression of slab surface is derived by applying ray tracing method, and it is free from the restriction in which the heat flux to the wall surface is zero and the gas is gray. The heat flux to slab surface of a walking beam reheating furnace is simulated. The expression provides theoretical basis for simplicity algorithm of heat flux to slab surface in on-line control mathematical model of reheating furnace. Furthermore, a new method is given to calculate total radiation exchange areas which provide advantages for correctly calculating the radiation heat exchange in reheating furnace.