关键词: 烧结床层, 燃烧, 传热传质, 气固换热, 数值模拟

Abstract: Based on the physical and chemical processes in sintering，a two-dimensional unsteady state mathematical model describing heat and mass transfer and combustion is developed.It takes into account the effects of bed structural parameters，such as particle equivalent diameter and porosity，with gas/solid heat transfer coefficient modified.By numerical simulation，the evolution of bed structure，temperature field，gas flow and composition distribution is obtained.The temperature of outlet gas and pressure drop of bed are in good agreement with measured data，which validates the mathematical model.Effects of fuel ratio，inlet air velocity，initial material temperature and other operational parameters are further analyzed.It is shown that the thickness of combustion zone and the maximum temperature increases in the sintering process.Changes of bed porosity and particle diameter mainly occur during the melting and condensation stage in the combustion zone.The maximum pressure loss appears in the melting zone，followed by the raw material layer，and the smallest loss is in the sintered layer.Increasing coke content or/and temperature of the raw material helps to improve sinter quality.Excessive air velocity would cause low quality and extra costs.

Key words: sintering bed, combustion, heat and mass transfer, gas/solid heat transfer, numerical simulation