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保护渣固态渣膜传热特性包括传导传热和辐射传热两种,固态渣膜传热特性会对铸坯表面质量产生重要影响。提出了一种能够描述多层介质中多次反射的数学模型并计算了通过渣膜的辐射传热量。基于能量守恒方程建立了一维稳态下的传导与辐射的耦合传热模型。根据计算所得的温度分布及辐射传热量讨论了影响保护渣综合传热的因素。计算结果表明:(1)通过固态渣膜的辐射传热量随着T~2/(1-R)的增加而逐渐增加;(2)固态渣膜反射率一定时,固态渣膜的吸收率越大,渣膜温度随距离的变化偏离线性关系越明显,靠近结晶器侧渣膜的温度随着固态渣膜反射率的增加而降低;(3)通过渣膜的辐射传热量在综合传热中所占的比例在10%~50%之间。由于辐射传热量降低的同时传导传热量在综合传热中所占的比例可能会升高,因此改变固态渣膜的光学性质并不一定能降低通过渣膜的综合传热量。
The heat transfer characteristics of the flux slag solid film include conduction heat transfer and radiation heat transfer. The heat transfer characteristics of the solid film can have a significant impact on the surface quality of the strand. A mathematical model capable of describing multiple reflections in multilayer media is proposed and the radiative heat transfer through the slag film is calculated. Based on the energy conservation equation, a one-dimensional coupled heat and transfer model of conduction and radiation is established. According to the calculated temperature distribution and radiative heat transfer, the factors that affect the comprehensive heat transfer of the mold powder are discussed. The results show that: (1) The radiative heat transfer through the solid slag increases gradually with the increase of T 2 / (1-R); (2) When the reflectivity of solid slag is constant, The larger the temperature of the slag film deviates from the linear relationship with the change of distance, the temperature of the slag film near the crystallizer side decreases with the reflectivity of the solid slag film increasing; (3) In the proportion of 10% to 50%. As the radiative heat transfer decreases while the conduction heat transfer increases in the overall heat transfer, changing the optical properties of the solid state slag film does not necessarily reduce the overall heat transfer through the slag film.