H_(2)SO_(4)/NH_(4)HSO_(4)作用下锅炉尾部受热面积灰成垢机理  

Scaling Mechanism of Fly Ash on Rear Heating Surfaces Under H_(2)SO_(4)/NH_(4)HSO_(4)

作　　者：韩高岩 吕洪坤 谢娜 周培焱 李易炜 肖海平[3] HAN Gaoyan;LYU Hongkun;XIE Na;ZHOU Peiyan;LI Yiwei;XIAO Haiping(E Energy Technology Co.,Ltd.,Hangzhou 310012,China;State Grid Zhejiang Electric Power Co.,Ltd.Research Institute,Hangzhou 310014,China;North China Electric Power University,Beijing 102206,China;Shanghai Electric Wind Power Group Co.,Ltd.,Shanghai 200233,China)

机构地区：[1]杭州意能电力技术有限公司,杭州310012 [2]国网浙江省电力有限公司电力科学研究院,杭州310014 [3]华北电力大学,北京102206 [4]上海电气风电集团股份有限公司,上海200233

出　　处：《浙江电力》2022年第2期78-85,共8页Zhejiang Electric Power

基　　金：杭州意能电力技术有限公司科技项目(EPRD2020-08)。

摘　　要：锅炉尾部受热面上的高强度垢影响了设备安全性和经济性。为阐明积灰成垢机理,进行了H_(2)SO_(4)/NH_(4)HSO_(4)与积灰的成垢实验,对灰垢样品进行扫描电镜形貌分析和X射线衍射成分分析,采用热力学平衡计算确定胶凝类物质。结果表明,H_(2)SO_(4)/NH_(4)HSO_(4)作用下灰粒表面产生絮状和针状结晶,粘连胶结为大块团聚体后形成灰垢,NH_(4)HSO_(4)作用下团聚固结更加明显。实验和热力学平衡计算表明,H_(2)SO_(4)与积灰反应生成石膏类硫酸盐胶凝材料;NH_(4)HSO_(4)与飞灰反应生成石膏类胶凝物质以及大量(NH_(4))_(2)SO_(4),具有更强结垢倾向。在H_(2)SO_(4)/NH_(4)HSO_(4)作用下,积灰反应生成的硫酸盐胶凝物质将松散灰粒粘连固结,导致低温受热面垢的形成。The high-intensity scale on the heating surface of a boiler holds up its security and economic efficiency.To clarify the scaling mechanism,scaling experiments where H_(2)SO_(4)/NH_(4)HSO_(4)reacted with fly ash were carried out.Scanning electron microscope morphology analysis and X-ray diffraction composition analysis were used to analyze the ash-scale morphology and composition supplemented with thermodynamics equilibrium calculation for determining cementing minerals which lead to scaling. The results showed that the flocculent and needle-like crystals formed on the surface of ash particles mixed with H_(2)SO_(4)/NH_(4)HSO_(4);ash particles adhered and cemented into large agglomerates to form ash-scale,and agglomeration was more remarkable mixed with NH_(4)HSO_(4). The experiment and thermodynamic equilibrium calculation showed that the fly ash reacted with H_(2)SO_(4)to generate gypsum-like gelatinous sulfate substances;NH_(4)HSO_(4)reacted with fly ash to generate gypsum-like gelatinous substances and a large amount of(NH_(4))_(2)SO_(4)that tend to scaling. Under H_(2)SO_(4)/NH_(4)HSO_(4),the gelatinous sulfates generated from actions of deposited ash consolidated the incompact ash particles,leading to the accumulation of ash scale on heating surface.

关 键 词：飞灰 结垢 胶凝材料 H_(2)SO_(4) NH_(4)HSO_(4) 

分 类 号：TK222[动力工程及工程热物理—动力机械及工程]