袋式除尘器含尘气体流动能耗的数值模拟分析与试验研究

发布时间：2018-04-11 07:15

本文选题：袋式除尘器 + 含尘气体流动　；参考：《东华大学》2013年博士论文

【摘要】：环保要求的提高和大气污染问题的日益突显,提高了对除尘技术的要求。大量燃煤机组静电除尘器面临即将改造为袋式除尘器,而改造项目中风机特性和系统可靠性对袋式除尘器的能耗提出了较高的要求。同时实际工程中存在部分袋式除尘器的运行能耗高或滤袋使用寿命短的问题,进而制约了袋式除尘器的迅速推广。袋式除尘器的除尘机理为滤料对颗粒物的过滤捕集,滤料作为核心构件对除尘器的影响体现在过滤阻力和失效性两个方面。过滤阻力相关研究集中在滤料捕集颗粒物后的阻力特性变化,而对运行能耗高的解释仍需完善,形成的机理仍需更加深入的分析。本课题以袋式除尘器内“气流流动—颗粒物运动—能耗”三者间的相互作用为研究对象,从含尘气体流动的角度分析了高能耗形成的原因,建立了相应评价方法并用于对结构设计和工程案例的应用。主要的研究工作如下： (1)建立了袋式除尘器能耗基本模型,分析了高能耗形成原因。通过对含尘气体流动过程中颗粒物运动的分析表明,袋式除尘器中过滤浓度升高是含尘气体流动影响能耗的主要方式,是高能耗形成的主要原因。 (2)建立了袋式除尘器气体流动的数值计算模型。通过对袋式除尘器内气流流动状态的分析,得到其内部同时存在三种状态气流流动区域,并以此为依据对比分析了试验测试结果与模拟计算结果,确定了模拟方法的合理边界层设置、简化方式及计算模型选择等,使模拟方法满足工程应用的要求。 (3)分析了气流组织对袋式除尘器能耗的影响,建立了相应的评价方法。通过对袋式除尘器结构运行参数的因子分析及交互作用分析,确定了袋式除尘器直接能耗的评价指标为除尘器计算阻力、返混流量比和滤料结构特性,间接能耗的评价指标为滤袋冲刷和滤料处理负荷。 (4)分析了滤料对袋式除尘器能耗影响,建立了相应的评价方法。通过对12种滤料过滤阻力试验结果的拟合分析,从能耗角度建立了滤料选择的评价方法,并简单分析了滤料结构特性对能耗的影响。 (5)应用评价方法分析了设备结构参数对能耗的影响。通过对袋式除尘器结构参数的因子分析,得到了影响袋式除尘器能耗的显著性因子及其影响规律。 (6)应用评价方法实现了对工程改造项目方案预测分析。通过工程改造项目4种方案的评价指标对比,得到了各设计方案中存在的问题及相互间的差异,该结果符合工程改造后的运行状况。
[Abstract]:The improvement of environmental protection requirements and the increasing problem of air pollution have raised the requirements of dust removal technology.The electrostatic precipitator of a large number of coal-fired units is about to be transformed into a bag dust collector, and the fan characteristics and system reliability in the retrofit project require higher energy consumption of the bag dust collector.At the same time, there are some problems in practical engineering, such as high energy consumption in operation or short service life of filter bag, which restricts the rapid popularization of bag filter.The dust removal mechanism of bag filter is the filtration and capture of particulate matter by filter media, and the influence of filter material as core component on dust collector is reflected in two aspects: filtration resistance and failure.The study of filtration resistance is focused on the change of resistance characteristics after the filter media capture particulate matter, but the explanation of high operating energy consumption still needs to be improved, and the mechanism of formation still needs to be further analyzed.In this paper, the interaction between "airflow, particle motion and energy consumption" in a bag filter is studied. The reasons for the formation of high energy consumption are analyzed from the point of view of the flow of dust-containing gas.The corresponding evaluation methods are established and applied to structural design and engineering cases.The main research work is as follows:1) the basic model of energy consumption of bag dust collector is established, and the reason of high energy consumption is analyzed.Through the analysis of particle movement during the flow of dust-containing gas, it is shown that the increase of filter concentration in bag dust collector is the main way to influence the energy consumption of dust-containing gas flow, and the main reason for the formation of high energy consumption.2) the numerical model of gas flow in bag dust collector is established.Through the analysis of the air flow state in the bag dust collector, it is found that there are three kinds of air flow regions in the bag dust collector at the same time. Based on this, the test results and the simulation results are compared and analyzed.The reasonable boundary layer setting, simplified method and calculation model selection of the simulation method are determined, so that the simulation method can meet the requirements of engineering application.The influence of airflow organization on energy consumption of bag dust collector is analyzed, and the corresponding evaluation method is established.Based on the factor analysis and interaction analysis of the structure operation parameters of the bag dust collector, the evaluation indexes of the direct energy consumption of the bag filter are determined as the calculation resistance of the bag filter, the ratio of back mixing flow and the structure characteristics of the filter material.Indirect energy consumption is evaluated by filter bag scouring and filter material treatment load.The influence of filter media on energy consumption of bag filter is analyzed and the corresponding evaluation method is established.Through fitting and analyzing the results of filtration resistance test of 12 kinds of filter media, the evaluation method of filter media selection is established from the point of view of energy consumption, and the influence of filter media structure on energy consumption is simply analyzed.5) the influence of equipment structure parameters on energy consumption is analyzed by using evaluation method.Based on the factor analysis of structural parameters of bag dust collector, the significant factor and its influence law of energy consumption of bag dust collector are obtained.6) applying the evaluation method to forecast and analyze the project plan of engineering transformation project.Through the comparison of the evaluation indexes of the four schemes of the engineering transformation project, the problems existing in each design scheme and their differences are obtained. The results accord with the operation condition of the project after the transformation.
【学位授予单位】：东华大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TU834.64;X701.2

【参考文献】