摘要
电厂运行中,硫酸氢铵(ABS)的生成及其与飞灰的相互作用会堵塞中间热媒体烟气换热器(MGGH)等换热面,然而目前ABS与飞灰的交互作用对换热面堵塞产生的影响特性与机理尚不明晰。通过搭建固定床反应系统,对不同温度、不同反应物浓度条件下ABS与飞灰相互作用机制进行试验研究,采用N 2吸附/脱附、X射线衍射和傅里叶红外光谱等表征手段对产物进行分析。结果表明:当烟气温度及烟气中SO_(3)、NH_(3)浓度升高时,飞灰表面ABS的沉积速率增大,促进污堵产物的生成;同时SO_(3)与NH_(3)浓度的提升会导致ABS初始沉积温度增大,扩大污堵产物的生成区间;飞灰中Fe、Ca、Mg、S等元素含量高,其反应后产物主要形态为硬度高的颗粒物。试验中观察到的4种典型产物的化学成分主要为硫酸盐、硫酸铵盐以及部分未参与反应的过量飞灰。其中,硫酸钙、硫酸镁等金属硫酸盐是造成MGGH污堵的主要原因,在低温段也能够由冷凝的H_(2)SO_(4)与飞灰反应形成。
In the operation of power plants,the generation of ABS and its interaction with fly ash can block the heat exchanger surface such as MGGH,however,the characteristics and mechanism of the interaction between ABS and fly ash on the blockage of the heat exchanger surface are not clear yet.In this paper,a fixed-bed reaction system was constructed to experimentally investigate the interaction mechanism between ABS and fly ash at different temperatures and different reactant concentrations,and the products were analysed by means of N_(2) adsorption/desorption,XRD and FT-IR.The results show that:When the flue gas temperature and the concentration of SO_(3) and NH_(3) in the flue gas increase,the deposition rate of ABS on the surface of fly ash increases,which promotes the generation of fouling products;At the same time,the elevation of the concentration of SO_(3) and NH_(3) leads to an increase in the initial deposition temperature of ABS,which enlarges the generation interval of the fouling products;With the high content of elements such as Fe,Ca,Mg,S,and so on,in the fly ash,the products after the reaction have the main morphology of the hardness particles.The chemical composition of the four typical products observed in the experiment was determined by XRD and FT-IR to be mainly sulphate,ammonium sulphate salts,and part of the excess fly ash not involved in the reaction.Among them,metal sulphates such as calcium sulphate and magnesium sulphate are the main causes of MGGH fouling,and are also able to be formed by the reaction of condensed H_(2)SO_(4) with fly ash in the low temperature section.
作者
刘实
陈国志
邓先洪
钟毓秀
张爱民
康锦锋
刘晓敏
雷嗣远
LIU Shi;CHEN Guozhi;DENG Xianhong;ZHONG Yuxiu;ZHANG Aimin;KANG Jinfeng;LIU Xiaomin;LEI Siyuan(Guizhou Newsky Environment&Tech Co.,Ltd.,Liupanshui 553000,China;Xiamen Newsky Energy Environment&Tech Co.,Ltd.,Xiamen 361000,China;State Key Laboratory of Coal Combustion,Huazhong University of Science and Technology,Wuhan 430074,China;Xi’an Thermal Power Research Institute Co.,Ltd.,Suzhou Branch,Suzhou 215153,China)
出处
《锅炉技术》
北大核心
2025年第1期77-82,共6页
Boiler Technology
