燃烧工况对燃煤电厂灰渣理化特性的影响

Effects of combustion conditions on the characteristics of fly ash and slag in coal-fired power plants

为拓展目前电厂粉煤灰的利用途径,以低挥发分煤在不同燃烧工况下形成的飞灰和底渣为研究对象,采用化学分析、X射线衍射、物理吸附仪、扫描电子显微镜、热重差热分析等测试手段,探讨各燃烧条件对灰渣理化性质的影响。结果表明,同一炉型锅炉负荷对粉煤灰比表面积、化学组成和物相组成等性质的影响较小,煤质种类和锅炉炉型对粉煤灰理化性质的影响较大;灰渣理化性质的区别,无论是化学组成、矿物种类以及微观形貌,均主要源于煤粉炉(PC)、循环流化床锅炉(CFB)与W火焰炉(WFB)燃烧温度的不同和煤质种类的影响。

In order to expand the comprehensive utilization of fly ash and slag from power plant, in this paper, fly ash and slag produced from combustion of low volatile coals in different types of boilers under different conditions were studied. To investigate the effectofcombus- tion conditionson the characteristics of fly ash and slag,the physical and chemical characteristics were analyzed by inductively coupled plasma （ ICP）, X- ray diffraction （ XRD ）, physical adsorption instrument （ BET ）, thermogravimetric analysis （ TG- DTG ） and scanning electron microscopy （SEM） ,etc. The results show that the effects of coal variety and boiler type on physicochemical propertiesof fly ash and slag are obvious, while the effects of operatingload of same type boiler onchemical composition, mineral matters and microscopic mor- phology of fly ash and slag are negligible. The characteristics of fly ash and slag are different, which is due to the difference of PC, CFB and WFB combustion temperature and the influence of coal quality.