循环流化床燃烧高钠准东煤的床料颗粒聚团特性  

Bed Particle Agglomeration in Circulating Fluidized Bed Burning High-sodium Zhundong Coal

作　　者：刘卓[1] 李建波[1] 龙潇飞 王泉海[1] 卢啸风[1] LIU Zhuo;LI Jianbo;LONG Xiaofei;WANG Quanhai;LU Xiaofeng(Key Laboratory of Low Grade Energy Utilization Technology and System,Ministry of Education(Chongqing University),Shapingba District,Chongqing 400044,China)

机构地区：[1]低品位能源利用技术及系统教育部重点实验室(重庆大学),重庆市沙坪坝区400044

出　　处：《中国电机工程学报》2022年第6期2248-2257,共10页Proceedings of the CSEE

基　　金：国家自然科学基金青年基金项目(51706028);重庆市研究生科研创新项目(CYB20020)。

摘　　要：为探究循环流化床(circulating fluidized bed,CFB)燃烧高钠准东煤过程的床料颗粒聚团特性,选择石英砂和高炉渣作为床料,在小型CFB实验系统上950℃燃烧准东煤,并使用环境扫描电镜、X射线衍射仪和X射线荧光光谱仪对底渣的表面和截面微观形貌、物相组分和化学成分进行分析,以揭示床料颗粒的聚团机理。结果发现石英床料工况时未团聚的床料颗粒表面形成富含Ca/Mg/Si/Fe亚微米颗粒的包覆层,而团聚的粗颗粒由未团聚颗粒通过Ca/Na/Si共熔体的“颈”结构粘结形成。粘性包覆层和低熔点Ca/Na矿物的存在促进了床料颗粒团聚。当使用高炉渣作为床料,底渣没有发现团聚粗颗粒,主要归结于其特殊的矿物和化学组分及表面物理结构,初步证实高炉渣具有作为替代性床料缓解床料颗粒聚团的潜力。This presented work presents an experimental investigation into bed particle agglomeration in a lab-scale circulating fluidized bed burning Zhundong coal at 950℃using quartz sand and blast-furnace slag(BFS)respectively as the bed material.The surface and cross-sectional morphology,mineralogy and chemistry of the bottom ash were analyzed by using Environmental SEM-EDS,XRD and XRF for revealing the mechanisms of particle agglomeration.Results show that in the quartz case,the surface of the discrete bed particle was coated by a layer of sub-micron particles being enriched in Ca/Mg/Si/Fe,whereas the agglomerated particles were bound by Ca/Na/Si eutectics as the“neck”.The presence of the sticky coating layer and low melting-points Ca/Na/Si eutectics would promote bed particle agglomeration.In the BFS case,the bottom ash was found not agglomerated as observed,due to its special mineralogy,chemistry and surface structure,preliminarily proving that BFS might be a potential viable bed material effectively alleviating bed particle agglomeration.

关 键 词：循环流化床 床料颗粒团聚 高炉渣 准东煤 

分 类 号：TM61[电气工程—电力系统及自动化]