间歇排渣型锁斗内部二相流动与传热数值模拟

为了获得集渣过程中锁斗温度的波动状况,建立三维非稳态模型,考察了锁斗内部固液二相的流动与传热。基于Mixture双流体模型描述二相耦合,液相采用Realizablek-ε湍流模型,颗粒相引入颗粒动力学理论,计算结果与工业数据吻合。考察了多个因素对锁斗平均温度的影响,结果表明:一个集渣循环结束时,锁斗收集渣量与稳态设计值基本一致,锁斗平均温度约57℃;渣的平均粒径越大,锁斗平均温度越高;锁斗平均温度随循环水量的增大而升高,当循环水量改变4 m3/h,将产生2.5—3℃温度波动。

Numerical simulation of solid-liquid flow and heat transfer in a batch slag-discharge lock hopper

To obtain the temperature fluctuations of lock hopper in a slag-collecting cycle,a 3-dimensional unsteady-state model was established to investigate the flow and heat transfer between solid and liquid in lock hopper.Based on the Mixture model,the liquid phase was simulated by Realizable k-ε turbulence model,and the particle phase was modeled with the kinetic theory of granular flow.The predicted results agree well with industrial data.The factors on the average temperature of lock hopper were studied.The results show that at the end of a slag-collecting cycle,the mass of collecting-slag is in accordance with the steady-state design value,and the average temperature of lock hopper is about 57 ℃.With increasing of the average diameter of slag particles,the average temperature of lock hopper increases.The average temperature of lock hopper increases with the higher recycle water flow rates,the change of 4 m3/h water flow rate causes 2.5-3 ℃ temperature fluctuation.