嵌入式电袋复合除尘器内部流场优化试验研究

发布时间：2018-01-05 01:33

本文关键词：嵌入式电袋复合除尘器内部流场优化试验研究　出处：《西安建筑科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：近年来,随着我国大气污染物中烟尘排放标准的提高,使得燃煤电厂需要使用更为高效的除尘设备以达到新的排放标准。目前,嵌入式电袋复合除尘器对于比较困难的煤种、高比电阻粉尘,具有适应性强的特点,在保证过滤风速的前提下,作为高效除尘设备已被广泛使用于燃煤电厂新建和改扩建项目。大型嵌入式电袋复合除尘器内部气流分布是关键的技术问题,直接关系到除尘器的本体阻力损失、布袋使用寿命。为了进一步优化除尘器内部流场,本文利用数值模拟方法,在电除尘器和袋式除尘器内部气流分布研究的基础上,以某燃煤电厂300MW机组嵌入式电袋复合除尘器为研究对象,对其内部气流分布进行研究分析,主要对第一电场入口速度均匀性、袋底上升气流速度、各滤袋单元气流分配、本体阻力损失等进行数值模拟计算,分析除尘器内部气流模拟结果,提出优化改进措施。并对不同工况负荷条件下,内部气流流动情况和阻力损失变化等进行研究分析。论文的主要结论如下:1.计算结果表明,优化后电袋复合除尘器内部气流流场在电场单元分布均匀,相对均方根值σ=0.24,满足气流分布设计要求,电场单元中能够使粉尘充分荷电,达到高效去除目的。2.滤袋各个单元中,气流分配非常均匀,最大偏差不超过2%,远低于10%的设计要求;滤袋袋底上升气流速度最大为1.18m/s,远小于1.5m/s的设计要求。有效的减小了上升气流流速,避免了二次附着现象,降低了运行阻力。3.随着负荷的增加,本体运行阻力也迅速增加,并得到负荷与运行阻力关系。该关系曲线可为不同工况负荷条件下,除尘器系统运行阻力损失的计算提供参考依据。4.数值模拟结果已应用于300MW锅炉机组工程中,该嵌入式电袋复合除尘器投运后,设备运行稳定、可靠,本体运行阻力损失为683Pa,出口烟尘排放浓度小于20mg/Nm3,完全达到国家新的烟尘排放标准。实际工程应用充分验证了数值模拟方法的实用性,有助于数值模拟方法在大型化电袋复合除尘器中的推广应用。
[Abstract]:In recent years, with the improvement of soot emission standards in China, coal-fired power plants need to use more efficient dust removal equipment to meet the new emission standards. The embedded electric bag composite dust catcher has the characteristic of strong adaptability for difficult coal and high specific resistance dust under the premise of ensuring the filtration speed. As a highly efficient dust removal equipment, it has been widely used in the construction and extension projects of coal-fired power plant. The airflow distribution in large embedded electric bag composite dust collector is a key technical problem. It is directly related to the loss of bulk resistance and the service life of cloth bag. In order to further optimize the internal flow field of the dust collector, the numerical simulation method is used in this paper. On the basis of the research on the internal airflow distribution of the electric precipitator and the bag dust collector, taking the embedded electric bag composite dust collector of a 300MW unit in a coal-fired power plant as the research object, the internal airflow distribution is studied and analyzed. The first electric field inlet velocity uniformity, bag bottom updraft velocity, airflow distribution of each filter bag unit, body resistance loss and so on are numerically simulated, and the results of airflow simulation inside the dust collector are analyzed. The optimization and improvement measures are put forward, and the variation of internal air flow and resistance loss are analyzed under different load conditions. The main conclusions of this paper are as follows: 1. The calculation results show that. After optimization, the airflow field in the electric field unit is uniform, and the relative root mean square value (RMS) 蟽 is 0.24, which meets the design requirements of the airflow distribution, and can make the dust fully charged in the electric field unit. In each unit of the filter bag, the airflow distribution is very uniform, the maximum deviation is not more than 2 parts, far below the design requirement of 10%; The maximum updraft velocity at the bottom of the filter bag is 1.18 m / s, which is much less than 1.5 m / s, which effectively reduces the upward flow velocity and avoids the secondary attachment. With the increase of load, the body running resistance also increases rapidly, and the relationship between load and running resistance is obtained. The relationship curve can be used under different load conditions. 4. The numerical simulation results have been applied to the 300MW boiler unit project. After the embedded electric bag composite precipitator is put into operation, the operation of the equipment is stable. Reliable, the body running resistance loss is 683 Pa. the outlet smoke emission concentration is less than 20 mg / Nm3. The practical engineering application fully verifies the practicability of the numerical simulation method, which is helpful to the popularization and application of the numerical simulation method in the large-scale electric bag composite precipitator.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X773

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