电除尘器进口封头内设置凝聚器对流场的影响

摘要

电凝聚技术是目前燃煤电厂P M2．5捕集增效的控制技术之一。将凝聚器设在电除尘器进口封头内，可扩大使用范围。参照某135 MW机组布置方式，利用流体动力学软件，构建几何模型并进行网格划分，分析凝聚器在第一层、第二层分布板间对气流的影响，计算进口封头内颗粒运动轨迹及湍流大小。结果表明：在电除尘器进口封头第一层、第二层分布板间设置凝聚器，能满足第一电场入口速度均匀性的要求；在第二层、第三层分布板下端，割掉0．5 m导流板，有利卸灰，但对气流均匀性影响较大；由湍流强度可知，将凝聚器设在第一层分布板前，可使荷电颗粒有更多碰撞、凝聚的概率，从而提高捕集P M2．5能力。%Electro-coagulation technology is one of the main technologies for controlling the PM2 .5 discharged from the coal-fired power plant currently.The application of coagulator can be expanded if set it in the inlet nozzle of electrostatic precipitator.In this paper,reference to the arrangement of a 135 MW unit,geometric model and meshing was done with the use of CFD software,and the effects of velocity distribution with the co-agulator arranged separately in the first and the second distribution plate ,and the particle traj ectories and tur-bulence intensity in the inlet nozzle were calculated.The results show that,it can satisfy the requirement of the velocity uniformity on the first electric field inlet with the coagulator arranged separately in the first and the second distribution plate;Cuting 0.5m guide plate under the bottom floor of second and third distribution board is good for ash removaling,while it is greater influence on the flow uniformity;On the basis of the tur-bulence intensity value,it can make the charged particles have more the probability of collision,condensation, thus improve the ability of PM2.5 capture ,with coalescer is located before the first distribution board.