350MW四角切圆锅炉水冷壁高温腐蚀及H_(2)S在线监测预警  

High Temperature Corrosion of Water Wall of 350MW Tangentially Fired Boiler and H_(2)S Online Monitoring and Early Warning

作　　者：彭志敏[1] 杜艳君 贺拴玲 王振[1] 丁艳军[1] 吕俊复[1] PENG Zhimin;DU Yanjun;HE Shuanling;WANG Zhen;DING Yanjun;LYU Junfu(Department of Energy and Power Engineering,Tsinghua University,Beijing 100084,China;School of Control and Computer Engineering,North China Electric Power University,Beijing 102206,China)

机构地区：[1]清华大学能源与动力工程系,北京100084 [2]华北电力大学控制与计算机工程学院,北京102206

出　　处：《锅炉技术》2022年第6期1-7,共7页Boiler Technology

基　　金：国家重点研发计划(2019YFB2006002);华能集团总部科技项目(HNKJ20-H50)。

摘　　要：针对某350 MW四角切圆锅炉水冷壁H_(2)S高温腐蚀现状,开展了水冷壁近壁面H_(2)S浓度在线监测及高温腐蚀预警应用示范研究。研究首先进行锅炉燃烧数值模拟并根据模拟结果选取H_(2)S监测测点,然后将基于可调谐二极管激光吸收光谱(TDLAS)结合恒流稀释烟气高保真预处理技术的H_(2)S在线监测系统应用于大型火电机组煤粉锅炉现场,采用轮测方式实现了锅炉炉膛“还原区”和“燃尽区”水冷壁近壁面H_(2)S浓度在线监测,同时基于监测数据反馈对水冷壁进行高温腐蚀预警。运行结果表明:锅炉炉膛内H_(2)S生成量与CO浓度呈正相关而与SO_(2)浓度呈负相关性,总硫守恒且仅与煤质中硫含量有关。因此,对水冷壁近壁面H_(2)S浓度进行实时在线监测预警,通过燃烧调整将H_(2)S浓度控制在合理范围内,可有效减缓低氮燃烧工况下水冷壁高温腐蚀速率,对燃煤锅炉尤其是高硫贫煤锅炉的安全运行具有重要意义。To investigate the H_(2)S related high-temperature corrosion of the water wall in a 350 MW tangentially fired boiler,in this paper,an application demonstration study of the H_(2)S concentration online monitoring near the water wall and the early warning of high-temperature corrosion were carried out.Firstly,the numerical simulation of boiler combustion was carried out and H_(2)S monitoring points were selected according to the simulation results.Then the H_(2)S on-line monitoring system based on TDLAS and high-fidelity pretreatment technology with constant-flow dilution principle for flue gas was applied to the field of pulverized coal boiler in large thermal power units.The alternating measurement strategy was adopted to realize the synchronous monitoring of H_(2)S concentration in both"reduction zone"and"burnout zone"of boiler furnace.Based on the monitoring data,the early warning for the high-temperature corrosion of the water wall was given.The long-term operation results show that the H_(2)S generation in the furnace is positively correlated with the CO concentration,but negatively correlated with the SO_(2)concentration.The monitored total sulfur is conserved and only related to the sulfur content in the coal.Therefore,it is of great significance to carry out real-time online monitoring and warning for H_(2)S concentration near the water wall.By controlling the H_(2)S concentration within a reasonable range through combustion adjustment,the rate for the high-temperature corrosion of water walls under low nitrogen combustion conditions can be effectively slowed down,which is of great significance to the safe operation of coal-fired boilers,especially for high sulfur lean coal boilers.

关 键 词：煤粉锅炉 可调谐二极管激光吸收光谱 恒流稀释 高温腐蚀预警 H_(2)S在线监测 

分 类 号：TH74[机械工程—光学工程]