钢包静置过程中传热现象的数值模拟

研究钢包静置过程中温度变化规律对控制钢液温度及后续连铸工艺有重要影响。利用ANSYS软件,建立三维钢包传热模型进行瞬态模拟,讨论了4%、6%和8%精炼渣厚度对钢包速度场、温度场以及钢包耐火材料壁温度分布的影响。计算过程采用两相流(钢液-精炼渣)模型,将精炼渣黏度设置为与温度有关的函数,渣-气自由表面和耐火材料表面施加对流和辐射混合边界条件。结果表明,增加渣层厚度可以有效减缓钢液速度场循环,起到保温作用,但会加剧钢液温度分层。钢液的散热功率主要集中在侧壁及钢渣界面,占总量的90%左右。渣层厚度由4%增加至6%,钢渣界面散热功率降低17.42%,继续增加至8%时,又降低了19.96%。

Numerical simulation of heat transfer during ladle holding period

The temperature control during ladle holding period has a significant effect on the continuous casting process. Using ANSYS software, a three-dimensional heat transfer model of ladle was established for transient simulation. The influences of 4%, 6% and 8% refining slag thickness on the velocity field and temperature field in molten steel and temperature distribution through ladle wall were studied. During the simulation, the two-phase flow model (steel-slag) was adopted as well as the variation of slag viscosity was used as a function of temperature, combined convection and radiation boundary conditions were applied to slag-air outface and refractory exterior surface. The results show that circulation of velocity field and heat loss in molten steel can be effectively weakened by increasing slag thickness, but it will aggravate thermal stratification of molten steel. The heat dissipation power of molten steel on sidewall and steel-slag interface is dominant, accounting for about 90%. When the thickness of slag layer increases from 4% to 6% and continues to 8%, the heat dissipation power of steel-slag interface decreases by 17.42% and 19.96%, respectively.