气烧石灰竖窑内温度场的数值模拟

Numerical simulation of temperature field in gas burning shaft lime kiln

气烧石灰环型竖窑内气体燃料在石灰石固体颗粒间流动燃烧是典型的多孔介质内燃烧传热问题。本文建立了三维多孔介质模型湍流非预混燃烧数学模型,对某厂日产300 t/d的气烧石灰环型竖窑内的温度场进行了仿真模拟研究。结果表明,不同的窑高对温度场的影响很大,通入煤气量一定的条件下,窑炉越矮,高温区距离出口处越近,出口处平均温度越高,烟气带出的热量越多,热量损失越大。建议该气烧竖窑应改造成16 m高料柱的窑体结构,煅烧石灰石使用的高炉煤气总体积流量最佳控制约为14875 m3/h。

The flow and combustion of the gas fuel in the gas burning shaft lime kiln is a typical problem of combustion in the porous medium. The temperature field of the gas burning shaft lime kiln where daily output is 300t/d is simulated by a turbulent non-premixed combustion model in porous medium. The results show that the height of kiln has a great influence on temperature field, in the condition of the same gas amount, the low- er the kiln affects, the shorter the distance from the high temperature area to the exit and more heat loss. It is suggested that the appropriate height of the gas burning shaft lime kiln should be rebuilt to 16m, and the vol- ume flow rate of the blast furnace gas should be appropriately reduced to 14 875 m3/h.