基于CFD的滤袋内侧磨损失效过程分析  

Analysis on the wear-out failure process of the inner surface of the filter bag based on CFD

作　　者：王赫 党小庆 曹利 郑华春 徐辉 张震 瞿晓燕 陈俞百 WANG He;DANG Xiaoqing;CAO Li;ZHENG Huachun;XU Hui;ZHANG Zhen;QU Xiaoyan;CHEN Yubai(Key Laboratory of Environmental Engineering of Shaanxi Province,School of Environment&Municipal Engineering,Xi’an University of Architecture&Technology,Xi'an 710055,China;Shanghai Bag Filtration Equipment Co.Ltd,Shanghai 200241,China;Fushun Tianyu filter material Co.Ltd,Fushun 113001,China)

机构地区：[1]西安建筑科技大学环境与市政工程学院陕西省环境工程重点实验室,西安710055 [2]上海袋式除尘配件有限公司,上海200241 [3]抚顺天宇滤材有限公司,抚顺113122

出　　处：《环境工程学报》2022年第2期535-545,共11页Chinese Journal of Environmental Engineering

基　　金：陕西省重点研发计划(2018ZDCXL-SF-02-04)。

摘　　要：针对某燃煤热电厂袋式除尘器滤袋破损和多次换袋检修失效现象,采用气固两相流数值模拟方法,对清灰气流含尘浓度过高导致滤袋破损失效的演变过程进行了分析,并结合现场调研和破损滤袋检测结果,明确了产生此类故障的原因。结果表明:喷吹总气量的22%为诱导气流,袋口上方的诱导气流速度接近7 m·s^(-1),上箱体内悬浮颗粒甚至袋口周边沉积的粉尘将在清灰气流的诱导作用下进入滤袋,并逐渐积累;袋内灰柱表面的粉尘受清灰气流扰动在沉积层上方反复磨损滤袋内侧净气面,磨损位置与积灰高度相关,均位于积灰表面上方50 mm范围内。模拟分析结果与检测结果一致,上箱体花板和滤袋内部长期积灰是导致滤袋破损失效的根本原因。根据上述研究结果提出了有针对性的维修方案并经现场实施后,袋式除尘器运行2年时间内再未发生滤袋破损失效现象,且烟气净化系统出口颗粒物排放浓度低于当地环保排放限值10 mg·m^(-3)。本研究结果可为判断滤袋健康状况及导致滤袋破损失效的直接原因提供参考。Aiming at the phenomenon that the breakage of filter bags and the failure of repeated bag replacement in a coal-fired thermal power plant,the evolution process of the filter bag’s damage caused by the cleaning airflow with high dust concentration was analyzed by gas-solid two-phase flow numerical simulation method.The cause of the failure was clarified combined with field investigation and the tests of damaged filter bags.The results showed that the 22%of the total airflow is the induced airflow,and the velocity of the induced airflow above the bag mouth is close to 7 m·s^(-1).The suspended particles in the upper box and even particles deposited around the mouth of the bag were inducted into the filter bag by the airflow and gradually accumulated in the bag.Therefore,the particles above the surface of the dust column will be disturbed by the airflow and repeatedly wear out the inner surface of the filter bag above the deposition layer.The wear position of the inner surface was related to the height of the dust accumulation in the bag,which was located within 50 mm above the deposition surface of the ash column in the bag.The simulation analysis was basically consistent with the on-site test results,the fundamental cause of filter bag breakage and failure was the long-time dust accumulation in the upper box and inside filter bags.Based on the research results,a targeted maintenance plan was proposed and implemented on site.No filter bag breakage and failure occurred during the operation of bag filter for 2 years,and the emission concentration of particulate matter at the outlet of the flue gas purification system was lower than the local environmental protection emission value of 10 mg·m^(-3).The results of this study can provide reference for judging the health status of filter bags and the direct causes of filter bag damage and failure.

关 键 词：脉冲袋式除尘器 喷吹清灰 气固两相流 粉尘沉积 滤袋内侧磨损 处置建议 

分 类 号：X513[环境科学与工程—环境工程]