SCR法烟气脱硝系统在300MW机组的应用与优化

发布时间：2019-04-27 19:02

【摘要】：随着雾霾的日益严重,人们的环保意识逐年增加,环境保护和治理的投入也跟着稳步提高,由于这些年社会用电量的激增,发电量也逐年递增,火力发电厂发电过程中会放出大量的粉尘和有害气体,2009年火力发电厂NOx排放达到860万吨,预计到2020年排放量将超过2600万吨,因此,研究氮氧化物NOx的生成机理、寻找控制NOx污染物的方法和手段,大幅减少燃煤电厂NOx排放,对人民生活、环境保护以及国民经济来说都是十分必要和重要的。选择性催化还原技术(SCR法)是一种被广泛用于火力发电厂烟气脱硝的技术,SCR法烟气脱硝技术占地面积小,技术成熟,容易操作,控制效果显著,已成为我国燃煤电厂控制NOx污染的主要手段之一。本文首先介绍了火电厂脱硝改造的背景、意义以及目前国内、外氮氧化物治理的进度;其次,重点介绍了SCR法烟气脱硝的主要反应原理;接着,本文以已经投入脱硝系统的华能太仓电厂为实例,结合实际情况对脱硝系统工艺流程进行讲解,详细介绍了SCR烟气脱硝系统的组成;然后,深入探讨了传统脱硝控制方案的优点与缺点,总结传统脱硝控制策略在实际应用中出现的一些问题,为了进一步满足脱硝系统的安全、高效运行,并节省喷氨量,华能太仓电厂1号机组对原有控制方案进行了升级,采用基于预测控制、神经网络学习技术及自适应控制技术的先进方案,升级后的性能试验表明,1号机组的脱硝效率得到了明显的提升,烟囱入口NOx浓度降至90mg/Nm3以下,较好地满足了环保指标要求和烟气脱硝自动化控制要求,该优化控制方案对其他电厂脱硝控制具有一定的借鉴意义。
[Abstract]:With the increasingly serious of haze, people's awareness of environmental protection has increased year by year, and the investment in environmental protection and management has also steadily increased. Due to the surge of social electricity consumption in these years, the power generation has also increased year by year. A large amount of dust and harmful gases will be emitted from the thermal power plant in the process of generating electricity. In 2009, the NOx emission from the thermal power plant will reach 8.6 million tons, and it is expected that the emission will exceed 26 million tons by 2020. Therefore, the mechanism of the formation of nitrogen oxide NOx is studied. It is very necessary and important for people's lives, environmental protection and national economy to look for ways and means to control NOx pollutants and reduce NOx emission greatly from coal-fired power plants. Selective catalytic reduction (SCR) is a technology widely used in flue gas denitrification in thermal power plants. The SCR flue gas denitrification technology has the advantages of small area, mature technology, easy operation and remarkable control effect. It has become one of the main means to control NOx pollution in coal-fired power plants in China. In this paper, the background, significance and progress of NOx treatment at home and abroad in thermal power plant are introduced firstly, secondly, the main reaction principle of flue gas denitrification by SCR process is mainly introduced. Then, taking Huaneng Taicang Power Plant which has been put into the denitrification system as an example, the process flow of the denitrification system is explained in combination with the actual situation, and the composition of the SCR flue gas denitrification system is introduced in detail. Then, the advantages and disadvantages of the traditional denitrification control scheme are deeply discussed, and some problems in the practical application of the traditional denitrification control strategy are summarized. In order to further meet the safety and high efficiency of the denitrification system, and save the amount of ammonia spraying, Unit 1 of Huaneng Taicang Power Plant has upgraded the original control scheme, adopting advanced scheme based on predictive control, neural network learning technology and adaptive control technology. The performance test after upgrading shows that the original control scheme is based on predictive control, neural network learning technology and adaptive control technology. The denitrification efficiency of no. 1 unit has been obviously improved, and the concentration of NOx at the entrance of chimney has been reduced to less than 90mg/Nm3, which can meet the requirements of environmental protection index and automatic control of flue gas denitrification. The optimal control scheme can be used for reference in the denitrification control of other power plants.
【学位授予单位】：苏州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X773

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