基于TDLAS的煤粉锅炉水冷壁近壁面CO/H_(2)S同步在线监测  

TDLAS-based synchronous on-line measurement of CO/H_(2)S near water wall of a pulverized coal boiler

作　　者：彭志敏[1] 贺拴玲 周佩丽 杜艳君 王振[1] 丁艳军[1] 吴玉新[1] 吕俊复[1] PENG Zhimin;HE Shuanling;ZHOU Peili;DU Yanjun;WANG Zhen;DING Yanjun;WU Yuxin;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：《热力发电》2022年第10期145-152,共8页Thermal Power Generation

基　　金：国家重点研发计划项目(2019YFB2006002);中国华能集团有限公司总部科技项目(HNKJ20-H50)。

摘　　要：煤粉锅炉低氮燃烧工况下还原性气氛H_(2)S和CO体积分数上升导致水冷壁高温腐蚀严重,实时在线监测水冷壁近壁面CO/H_(2)S体积分数并基于测得的数据建立高温腐蚀预警模型具有重要意义。采用可调谐二极管激光吸收光谱(TDLAS)技术测量锅炉水冷壁近壁面CO/H_(2)S体积分数,首先利用赫里奥特多次反射池提高测量精度并降低检测限,然后开展CO/H_(2)S体积分数动态测量验证实验。结果表明,CO、H_(2)S分别在0~2000μL/L和0~20μL/L范围内,测量值与配比值一致且具有较高的精度。最后结合恒流稀释烟气高保真预处理技术将研制的CO/H_(2)S监测装置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”CO/H_(2)S同步在线监测;同时基于监测数据反馈对锅炉燃烧进行调整,在确保烟气超低排放基础上减缓水冷壁高温腐蚀速率,实现火电机组高效、环保、安全和智能化运行。The increase of CO and H_(2)S volume fraction leads to severe high-temperature corrosion of water wall of pulverized coal boiler under low nitrogen concentration combustion condition.Therefore,it is of great significance to monitor the volume fraction of CO and H_(2)S on near-wall surface in real time and establish an early warning model for high-temperature corrosion based on the measured data.In this work,the tunable diode laser absorption(TDLAS)technology was used to measure the volume fraction of CO and H_(2)S near the boiler water wall.Firstly,Herriot multiple reflection cell was used to improve the measurement accuracy and reduce the detection limit.Then the dynamic measurement of CO/H_(2)S volume fraction was carried out to verify the proposed experimental approach.Preliminary results showed that the measured CO and H_(2)S volume fractions agree very well with the preset values in the range of 0 to 2000μL/L and 0 to 20μL/L respectively with high measurement accuracy.Finally,combined with the high-fidelity pretreatment technology of flue gas based on the principle of constant-flow dilution,the developed CO/H_(2)S monitoring device was applied to the field of pulverized coal boiler in large thermal power units.The alternating measurement strategy was applied to realize synchronous on-line monitoring of CO/H_(2)S in both“reducing zone”and“burnout zone”of boiler furnace.Based on the monitoring date,the boiler combustion was further adjusted to slow down the high-temperature corrosion rate of the water wall while ensuring ultra-low emission from flue gas.Eventually,the efficient,environmentally friendly,safe and intelligent operation of thermal power unit was realized.

关 键 词：可调谐二极管激光吸收光谱 煤粉锅炉 水冷壁高温腐蚀 CO/H_(2)S在线监测 

分 类 号：TH74[机械工程—光学工程]