富拉尔基热电厂超低排放研究及方案选定

发布时间：2018-02-14 18:01

  本文关键词： 超低排放 SCR脱硝系统 布袋除尘器的改造 石灰石-石膏湿式脱硫改造 风机阻力复核　出处：《山东大学》2017年硕士论文　论文类型：学位论文

【摘要】：2010年以来国家烟气污染物减排工作不断推进,燃煤火力发电机组在减排实施过程中,逐步形成并完善了脱硝、除尘、脱硫超低排放的技术改革,从而使得发电设备在运行过程中产生的烟气污染物的排放指标达到预期值。由于燃煤品号、热值、燃烧形成的污染物含量以及燃煤锅炉机组参数、脱硝除尘脱硫容量各不相同,每一台机组实现"超低排放"的系统技术工艺、经济效益、环保社会效益等方面存在较大差异,因此针对每台机组的超低排放研究成为近期本领域的热点。本文首先查阅相关文献,对火力发电厂超低排放的国内外研究现状及工艺路线、最新研究进行了相关介绍。基于富拉尔基热电厂一期"上大压小"扩建工程,本文对原设计SCR脱硝工程、五室布袋除尘器设备、石灰石-石膏湿式脱硫工艺系统进行分析论证,并查找原设计指标与"超低排放"标准的差距与改进点。在满足排放指标要求的前提下,尽量利用现已建成设施,本着尽量少拆、节约投资的原则,制定出一套超低排放达标、兼具经济性的最佳方案。本文分别详述了在该工程超低排放改造中降低NOx、烟尘和SO_2排放的工艺路线:1、原有SCR脱硝系统增加催化剂层的两种改进方式进行经济性对比从而优选;2、五室布袋除尘器改造七室布袋除尘器使烟尘排放达到超低排放指标和脱硫后增加湿式静电除尘器两种方案在设计建造及经济性对比从而优选对烟尘进行超低排放改造;3、脱硫系统增加一层喷淋层以达到复核煤种超低排放达标的目的。4、对引风机系统进行了相对应的改造技术参数复核工作。研究发现,方案一将原SCR催化剂模块增加到新设计高度、原五室布袋除尘器改为七室、在原脱硫吸收塔内增加一层喷淋,和方案二:将原SCR催化剂增加一层催化剂、五室布袋除尘器不变,在脱硫后增加湿式静电除尘器、脱硫增加一层喷淋,均能达到"超低排放"改造需求。综合工程建设经济性及对工程进度、施工要求和配套设施等因素,本研究对两套方案的投资成本和技术实施可行性进行了论证,最终选定方案一为本工程超低排放的优选方案。目前,本工程已按此超低排放改造方案实施,在建造过程中按照超低排放工艺要求高标准建设并达到经济性最优。根据此次改造的工艺选择,在今后的生产运营过程中本工程将实现NOx排放≤50mg/Nm3、烟尘排放≤5mg/Nm3、SO_2排放≤35mg/Nm3的排放指标。本文以富热电项目超低排放改造方案选定为研究方向,能够为东北地区褐煤炉型机组超低排放改造提供借鉴经验。本工程"超低排放"改造的实施,相应国家燃煤电厂节能减排方针。为齐齐哈尔市乃至黑龙江省经济建设的可持续发展做出贡献,对改善齐齐哈尔市居民的生活质量也将起到积极的促进作用,同时改造工程产生的环境效益、经济效益及社会效益十分显著。后续,我们将根据运行参数,进一步验证其实际运营效果。
[Abstract]:Since 2010, the national emission reduction of flue gas pollutants has been continuously promoted. During the implementation of the emission reduction of coal-fired thermal power units, the technological reform of denitrification, dust removal, desulfurization and ultra-low emissions has been formed and perfected step by step. As a result, the emission index of flue gas pollutants produced during the operation of power generation equipment reaches the expected value. Due to the number of coal, the calorific value, the content of pollutants formed by combustion and the parameters of coal-fired boiler unit, the capacity of denitrification and dedusting and desulphurization are different. There are great differences in the system technology, economic benefits, environmental protection and social benefits of realizing "ultra-low emission" for each unit. Therefore, the research on ultra-low emission of each unit has become a hot spot in this field in the near future. First of all, this paper refers to the relevant literature, the domestic and foreign research status and technological route of ultra-low emission in thermal power plants. Based on the expansion project of "large pressure and small pressure" in the first phase of Fullerji Thermal Power Plant, this paper analyzes and demonstrates the original design of SCR denitrification project, five-chamber bag dust collector equipment, limestone gypsum wet desulfurization process system. And find out the difference and improvement point between the original design index and the standard of "ultra low emission". On the premise of meeting the requirement of emission target, we can make use of the existing facilities as far as possible, and in the principle of minimizing demolition and saving investment, we can work out a set of ultra-low emission standard. In this paper, the process route of reducing no _ x, soot and SO_2 emissions in the ultra-low emission revamp of the project is described in detail. The two improvement ways of adding catalyst layer to the original SCR denitrification system are analyzed. The improvement of bag Precipitator in Seven rooms so that the discharge of smoke can reach the ultra-low emission target and the wet electrostatic precipitator is added after desulphurization two schemes are compared in design construction and economy so as to optimize the selection of soot dust in the design and construction of the wet electrostatic precipitator with the addition of wet electrostatic precipitator after desulphurization. In order to meet the goal of rechecking the ultra-low emission of coal by adding a spray layer to the desulphurization system, the retrofit technical parameters of the induced fan system are reviewed. The first plan is to add the original SCR catalyst module to the new design height, the original five-compartment bag dust collector will be changed into seven chambers, and the original desulfurization absorber will be added with a layer of spray, and scheme two: the original SCR catalyst will be added with one layer of catalyst, and the five-compartment bag dust collector will remain unchanged. Adding wet electrostatic precipitator after desulphurization and adding a layer of spray to desulphurization can all meet the demand of "ultra-low discharge" transformation. The economy of comprehensive project construction and the factors such as the progress of the project, construction requirements and supporting facilities can be achieved. In this study, the investment cost and the feasibility of technical implementation of the two sets of schemes have been demonstrated. Finally, the first scheme has been selected as the optimal scheme of ultra-low emission of the project. At present, the project has been implemented according to this ultra-low emission transformation scheme. In the construction process according to the ultra-low emission process requirements high standards of construction and achieve economic optimization. According to the process selection of this transformation, In the process of production and operation in the future, the project will realize the emission targets of NOx 鈮，

本文编号：1511281