燃煤供热锅炉袋式除尘器内部气流组织和结构优化试验研究

发布时间：2018-05-08 02:17

本文选题：燃煤供热锅炉 + 袋式除尘器　；参考：《西安建筑科技大学》2015年硕士论文

【摘要】：日渐严格的环保标准对燃煤供热锅炉烟气净化系统提出了更高的要求,而除尘系统作为烟气整体净化系统的重要组成部分,占据了举足轻重的地位。袋式除尘器受锅炉负荷变化的影响较小,能够确保烟尘排放浓度在20mg/m3以下,具有一定的稳定性和可靠性。但在实际运行过程时,常常会因内部气流组织不均等有原因而导致滤袋破损和运行阻力过大等问题的发生。数值模拟方法作为研究袋式除尘器内部气流流动状态的手段之一,可以为改善除尘器内部气流组织和结构优化提供有效的指导。本文以某100t/h燃煤供热锅炉袋式除尘器为研究对象,利用数值模拟软件Fluent研究其内部流场,合理简化其内部结构,以滤袋单元迎面气流速度、袋底上升气流速度、滤袋单元流量分配、除尘器本体阻力损失等为评价指标,结合Fluent软件与Tecplot软件进行模拟结果后处理,对其内部结构进行优化。得出以下结论:1)处理风量一定,增加一个进口喇叭可以在一定程度上减小滤袋迎风断面最大气流速度以及降低除尘器运行阻力;2)导流通道起到了分流作用,滤袋单元迎面气流速度明显减小,降低了对除尘器前排滤袋单元的冲刷作用;3)灰斗挡风板使除尘器灰斗内的扰流现象得到明显改善,但同时也导致除尘器运行阻力有所增加;4)除尘器在某供热锅炉除尘系统应用以来,性能稳定。现场实测结果显示,除尘器满负荷运行阻力小于600Pa,锅炉80%负荷运行时除尘器出口粉尘排放浓度均小于20mg/m3,满足《锅炉大气污染物排放标准》(GB13271-2014)要求,数值模拟结果可以为供热锅炉袋式除尘器的选型设计以及除尘系统风机的选型提供理论指导;5)结合Fluent软件和Tecplot软件进行模拟结果后处理,可以更清晰的了解除尘器内部的气流流动状况。
[Abstract]:The increasingly stringent environmental protection standards put forward higher requirements for the flue gas purification system of coal-fired heating boilers. As an important part of the whole flue gas purification system, the dust removal system occupies a pivotal position. The bag dust collector is less affected by boiler load change, and can ensure the dust emission concentration below 20mg/m3, which has certain stability and reliability. However, in the actual operation process, the damage of filter bag and the excessive running resistance often occur due to the uneven internal airflow organization. Numerical simulation method is one of the methods to study the airflow state in the bag dust collector, which can provide effective guidance for improving the airflow organization and structure optimization in the bag dust collector. In this paper, the bag dust collector of a 100t/h coal-fired heating boiler is taken as the research object, the internal flow field is studied by using the numerical simulation software Fluent, the internal structure is reasonably simplified, and the forward airflow velocity of the filter bag unit and the updraft velocity at the bottom of the bag are used. The flow distribution of the filter bag unit and the resistance loss of the dust collector were used as the evaluation indexes. The internal structure of the filter bag unit was optimized by the post-processing of the simulation results with the combination of Fluent software and Tecplot software. The following conclusion is drawn: (1) with a constant air flow rate, adding an inlet horn can to some extent reduce the maximum airflow velocity at the upwind section of the filter bag and reduce the running resistance of the dust collector.) the diversion channel plays a shunt role. The direct airflow velocity of the filter bag unit is obviously reduced, and the scour action of the filter bag unit in the front row of the dust collector is reduced. (3) the dust bucket windshield can obviously improve the scrambling phenomenon in the dust collector hopper. But at the same time, the operation resistance of the dust collector has been increased. (4) the performance of the dust collector has been stable since it was applied in the dust removal system of a heating boiler. The field test results show that the operating resistance of the dust collector at full load is smaller than that of 600Pa.The dust emission concentration at the outlet of the dust collector is less than 20mg / m3 when the boiler is running at 80% load, which meets the requirements of the Standard for the discharge of Atmospheric pollutants of the Boiler GB13271-2014. The numerical simulation results can provide theoretical guidance for the selection design of bag dust collector of heating boiler and the selection of fan of dust removal system. (5) combined with Fluent software and Tecplot software, the simulation results can be post-processed. A clearer picture of the air flow inside the dust collector can be obtained.
【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】：X701.2

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