准东煤灰与液态排渣煤粉炉耐火材料的烧结特性  

Sintering Characteristics of Zhundong Coal Ash and Refractory Material of Slag Tap Pulverized Coal Boiler

作　　者：龚宇森 傅培舫[1] 刘洋[1] 别康 Gong Yusen;Fu Peifang;Liu Yang;Bie Kang(State Key Laboratory of Coal Combustion,School of Energy and Power Engineering,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]华中科技大学能源与动力工程学院,煤燃烧国家重点实验室,武汉430074

出　　处：《燃烧科学与技术》2021年第1期67-73,共7页Journal of Combustion Science and Technology

基　　金：国家重点研发计划资助项目(2018YFB0604102).

摘　　要：采用TGA-DSC分析确定了准东煤灰和其混合灰样(不同质量比的准东煤灰和耐火材料)燃烧过程中的特征温度,并分别采用XRD和FSEM-EDS对不同特征温度段灰样进行矿物识别和形貌、能谱分析,得到了原灰与混合灰的烧结温度、灰中主要矿物的转化和熔融过程,并对比了不同耐火材料含量的煤灰熔融温度;在此基础上提出了耐火材料构型的极限热载荷概念评价其耐热性能.研究表明:碳化硅耐火材料降低了准东煤灰的变形温度DT(1130℃降低到1080℃),促进煤灰与耐火材料的烧结形成致密的挂渣保护层;同时灰的烧结会使耐火材料承受极限热载荷能力降低近1/3.1200℃之后,耐火材料中SiC在煤灰的作用下发生氧化,造成材料失效,故在锅炉运行过程中要严格控制挂渣与耐火材料交界面处的温度.耐火材料增加煤灰在高温下的黏度,提高了煤灰的流动温度TF,更加利于煤灰在耐火材料表面形成牢固稳定的熔渣保护层.The TGA-DSC analysis of Zhundong coal ash and mixed ash(different mass contents of Zhundong coal ash and refractory material)were carried out to determine their characteristic temperatures in the combustion process,and XRD and FSEM-EDS were used to conduct mineral identification and the analysis of the morphology and composition of ash samples in different characteristic temperature sections,then obtained the sintering temperatures of ash samples,as well as conversion and melting processes of the main minerals in the ash samples,we also compared the ash fusion temperatures of these different ash samples;the concept of ultimate thermal load of refractory configuration is proposed based on the above analysis,which is an index to evaluate thermal stability of refractories.Experimental results show that SiC refractory material reduced the deformation temperature of coal ash(from 1130℃to 1080℃),and promoted the sintering of coal ash and refractory material to form a dense protective layer.The sintering of coal ash reduced the ultimate thermal load of the refractory material by one third.After 1200℃,SiC in the refractory material was oxidized under the effect of coal ash.Therefore,the temperature at the interface between the slag and the refractory material must be strictly controlled during the operation of the boiler.Refractory materials increased both the viscosity of coal ash at high temperature and its flow temperature,which was more conducive to the formation of a solid and stable slag protective layer on the surface of refractory material.

关 键 词：准东煤 液态排渣 耐火材料 烧结 矿物相变 

分 类 号：TK16[动力工程及工程热物理—热能工程]