W型火焰锅炉分区混合动态喷氨控制系统  

Control system of partitioned hybrid dynamic ammonia injection for W-type flame boiler

作　　者：贾晓静[1,2] 李刚 武宝会[1,2] 李明皓[2] 秦昶顺 许博 王小成 JIAXiaojing;LI Gang;WU Baohu;LI Minghao;QIN Changshun;XU Bo;WANG Xiaocheng(Xi'an Thermal Power Research Institute Co.,Ltd.,Xi'an 710054,China;Xi'an Xire Boiler Environmental Protection Engineering Co.,Ltd.,Xi'an 710054,China)

机构地区：[1]西安热工研究院有限公司,陕西西安710054 [2]西安西热锅炉环保工程有限公司,陕西西安710054

出　　处：《热力发电》2020年第3期141-147,共7页Thermal Power Generation

摘　　要：针对W型火焰锅炉脱硝系统的还原剂用量偏高以及氨逃逸较高的问题,在分区混合动态喷氨技术的基础上,采用Modbus RTU的485总线通信方式,研究先进的分布式控制系统(DCS)外挂控制系统,提出了“SCR Control+”控制技术与“均衡控制”方法相结合的控制策略。具体方案为:1)SCR Control+整体排放量优化控制;2)建立一套系统专家数据库,作为分区喷氨量均衡控制模型建立的基础,并通过先进的动态矩阵控制(DMC)优化控制算法,灵活地调整控制规律,适应控制对象特性和机组运行工况的变化,并计算出各分区输出NOx量;3)利用各分区之间反馈值的偏差与偏差的变化速率搭建控制集合,并与目标进行分析比较,修正各分区的阀门开度,达到分区精确均衡控制的目的。该系统应用于湖南某电厂W型火焰锅炉机组,在降低还原剂用量和控制氨逃逸方面取得了良好的效果。Aiming at the problem of high dosage of reductant and high ammonia escape in denitrification system of W-type flame boiler,a control strategy combining SCR Control+control technology with balanced control method is proposed based on the partitioned hybrid dynamic ammonia injection technology,combining with 485 bus communication mode of Modbus RTU and the external control system of Distributed Control System(DCS).The specific scheme is as follows:1)SCR Control+overall emission optimization control is adopted;2)a system expert database is established to serve as the basis of the partition ammonia spray equilibrium control model,and the dynamic matrix control(DMC)optimization control algorithm is used to adjust the control law flexibly,so as to make the unit adapt to the change of the controlled object’s characteristics and unit’s operating conditions and calculate the output NOx of each partition.By using the deviation of feedback value and the variation rate of deviation between the partitions,the control set is set up and compared with the target,so as to correct the valve opening of each partition and achieve the goal of precise equalization control zoning.This system has been applied to a W-type flame boiler unit in a power plant in Hunan province,and the result shows that good effects have been achieved in reducing the amount of reducing agent and controlling ammonia escape.

关 键 词：W型火焰锅炉 SCR Control+ 均衡控制 动态矩阵控制 氨逃逸 分区混合 动态喷氨 控制系统 

分 类 号：TP29[自动化与计算机技术—检测技术与自动化装置]