燃煤电厂脱硝系统优化研究

发布时间：2018-06-25 11:26

本文选题：氮氧化物 + SCR脱硝技术　；参考：《华北电力大学》2014年硕士论文

【摘要】：氮氧化物是主要的大气污染物之一，严重危害人体健康，是酸雨的主要来源；同时氮氧化物还会生成光化学烟雾，并参与臭氧层的破坏。2011年新《火电厂大气污染物排放标准》的执行对燃煤电厂氮氧化物的排放提出了更加严格的限制。选择性催化还原（SCR）以其高效、可靠、结构简单等优点成为燃煤电厂控制氮氧化物的必然选择。然而，SCR烟气脱硝系统在其运行中出现了能耗增加、氨氮混合不均匀、氨逃逸堵塞下游设备等诸多问题。本文着重从SCR节能分析和喷氨格栅参数调整两个方面入手，对燃煤电厂脱硝系统进行了优化。在SCR脱硝系统中，，引风机、稀释风机是主要的能耗设备，其运行状态会影响系统的总体能耗。本文结合热力学分析、数学建模和数据拟合，对SCR主要能耗设备性能进行建模，寻找设备运行能耗、机组负荷、煤质变化、脱硝性能四者之间的关系，绘制出设备运行能耗特性曲线图。之后结合300MW机组运行数据，定量分析脱硝系统能耗特性，并提出主要能耗设备的具体优化运行方案。在喷氨格栅参数调整中，首先利用FLUENT模拟软件对具有不同几何参数的喷氨格栅的混合效果进行模拟，并得出混合2m之后截面上氨浓度的标准偏差系数，利用数据拟合的方法求出浓度标准偏差系数与几何参数之间的非线性函数关系。通过对该关系式进行求解，得出氨氮混合最优的喷氨格栅布置方式。本文通过以上两个方面的调整，降低了脱硝系统的能耗，提高了氨氮混合的效果，在一定程度上，为燃煤电厂SCR烟气脱硝系统的技术改造提供了理论依据。
[Abstract]:Nitrogen oxide is one of the main atmospheric pollutants, which seriously endangers human health and is the main source of acid rain. At the same time, nitrogen oxide also produces photochemical smog. The implementation of the new Standard of Atmospheric Pollutant emissions from Thermal Power plants in 2011 puts forward more stringent restrictions on the emission of nitrogen oxides from coal-fired power plants. Selective catalytic reduction (SCR) is an inevitable choice for controlling nitrogen oxides in coal-fired power plants due to its high efficiency, reliability and simple structure. However, in the operation of SCR flue gas denitrification system, there are many problems, such as increasing energy consumption, uneven mixing of ammonia and nitrogen, blocking downstream equipment of ammonia escape and so on. This paper focuses on the optimization of denitrification system in coal-fired power plant from the aspects of SCR energy saving analysis and parameter adjustment of ammonia grille. In SCR denitrification system, the main energy consumption equipment is induced fan and dilute fan, and its running state will affect the overall energy consumption of the system. Combined with thermodynamic analysis, mathematical modeling and data fitting, this paper models the performance of SCR main energy consumption equipment, and finds out the relationship between the operating energy consumption, unit load, coal quality change and denitrification performance. Draw the curve of energy consumption characteristics of equipment operation. Combined with the operation data of 300MW unit, the energy consumption characteristics of denitrification system are quantitatively analyzed, and the specific optimal operation scheme of the main energy consumption equipment is put forward. In the parameter adjustment of ammonia spray grille, the mixing effect of ammonia spray grille with different geometric parameters is simulated by fluent simulation software, and the standard deviation coefficient of ammonia concentration on the cross section after 2m mixing is obtained. The nonlinear function relationship between the standard deviation coefficient of concentration and geometric parameters is obtained by using the method of data fitting. By solving the relationship, the optimal arrangement of ammonia-nitrogen mixing grille is obtained. Through the adjustment of the above two aspects, the energy consumption of denitrification system is reduced and the effect of ammonia nitrogen mixing is improved. To a certain extent, it provides a theoretical basis for the technical transformation of SCR flue gas denitrification system in coal-fired power plant.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：X773

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