基于多相流仿真技术的火电厂输煤筛碎转运点优化设计

Optimal design of transshipment point of coal screening-crushing system in heat-engine plant based on multiphase flow simulation technology

火电厂输煤系统燃煤转运过程中产生大量粉尘污染,文中针对输煤系统中筛分-破碎系统下转运点进行了优化,建立了输煤筛碎系统多相流仿真模型,对其内部的气-液-固多相流运动进行了数值模拟仿真,并依据仿真结果对该转运点的溜管和导料槽进行了优化设计。对比优化前后的仿真结果,料流对溜管内气体的压缩、诱导效应明显减弱,改进后的导料槽内部气流通过泄压仓溢出,降低了全封闭导料槽内的气压,同时在多级阻尼板的作用下,气流速度减少,极大减少了粉尘从导料槽的挡尘帘处溢出,有效改善了筛碎转运点的粉尘污染情况。

During coal transportation with coal conveying system in the heat-engine plant,a large amount of dust will be produced.In this paper,transshipment points of the screening-crushing system of coal conveying system are optimized,and a multiphase flow simulation model of the screening-crushing system of coal conveying system is established.The gas-liquid-solid multiphase flow movement in the system is simulated numerically,and chutes and guide chutes of transshipment points are optimized according to simulation results.The comparison of simulation results before and after optimization shows that the compression and induction effects of the material flow on the gas in the guide chute are obviously reduced,and the air flow in the improved guide chute is discharged through a decompression bin,which reduces the pressure inside the fully enclosed guide chute.Meanwhile,with the multi-stage damping plate,the air flow speed is lowered,which greatly restrain the dust overflow at the check curtain of the guide chute and effectively reduce the dust pollution at transshipment points of the screening-crushing system.