三维分格式焦炉蓄热室传热分析与数值模拟

通过构建真实比例的三维分格式焦炉蓄热室模型,利用CFD软件,模拟计算了实际炼焦过程中蓄热室内周期性非稳态的传热过程,计算值与实际测量值相吻合。结果表明,分格式焦炉蓄热室顶部空间处,在加热期内容易产生较强的气体涡流运动,加强了其与格子砖的换热作用,导致了加热初期的温度梯度异常;得到了不同高度的焦炉格子砖内气固两相温度的周期性变化规律。还考察了格子砖导热系数以及废气流量分配系数对于蓄热室换热效果的影响,发现格子砖导热系数的增大,将导致蓄热室温度效率降低、出口气体温降升高,变化规律呈线性相关;发现操作条件下最佳的废气流量分配系数约为0.94,该废气流量分配系数下的空气与煤气蓄热室的温度效率最为接近。

Three dimensional heat transfer model and numerical simulation of cellular regenerative chamber of coke oven

The periodic unsteady heat transfer process of the regenerative chamber in the actual coking process is calculated using CFD software to construct a real scale model of the cellular regenerative chamber of coke oven. And the calculated value is consistent with the actual measured value. It is found that the gas flow in the top space of the chamber has strong eddy current motion during the heating period, which strengthens the heat transfer between gas and the lattice brick and causes the abnormal temperature gradient at the early stage of heating. The periodic changing temperature of gas and solid in different height of coke oven lattice brick is obtained. The influence of the thermal conductivity of the lattice brick and the distribution coefficient of the exhaust gas flow on the heat transfer effect of the regenerator is also investigated. It is found that the increase of the thermal conductivity of the lattice brick will reduce the temperature efficiency of the regenerator and increase the temperature drop of the gas at the outlet of the chamber, and the change rule was linear. The optimal distribution coefficient of the waste gas flow under the operation condition is about 0.94. Under this distribution coefficient of exhaust gas flow, the temperature efficiency of the air and the gas regenerative chamber is nearly the same with each other.