基于步进式加热炉数学模型的氧化烧损预测模拟

Numerical Simulation of Oxidation Depending on the Model of Walking Beam Type Reheating Furnace

针对钢铁企业的氧化烧损问题,用数值模拟的方法进行预测分析。利用CFD流体计算软件建立了炉内流动、燃烧、辐射、钢坯导热和氧化烧损模型,流动模型采用κ-ε湍流模型,燃烧采用PDF燃烧模型,辐射换热模型采用离散坐标(DO)辐射模型,热流密度做为钢坯导热的边界条件,模拟钢坯在实际工况下的结果表明,氧化铁皮的快速增长期是在钢坯人炉50～120min之间,位于加热段;在不同均热时间下,钢坯氧化率随均热时间呈线性增长。据此结论,现场操作人员可通过强化加热段加热能力的手段减少钢坯在加热段的停留时间或热装钢坯调整总的在炉时间来降低钢坯氧化烧损率以提高钢坯加热质量。

An oxidation of prediction model has been developed for solving the problem of oxidation in iron and steel enterprises, which in- eludes the k - ε two-equation model for turbulent flow, discrete ordinates model for radiative heat transfer and the PDF combustion model for gaseous reaction. Heatfluxaroundtheslabsisintroducedastheboundaryconditionofthetransientconductionequationoftheslab. Prediction of the growth of oxidation has been simulated in the actual operation. The result shows that the height rate of oxidation growth take place at the heating time from 50 minutes to 120 minutes when the slab is in heating zones; The growth rate of the scale is a parabolic function of the soaking time. Operators can improve the quality of the slab that has a low oxide rate by means of enhance the heating capacity or thermal loading for the slab according to the simulated result.