摘要
准东煤田是我国目前最大的整装煤田,煤质总体呈现中高水分、中高挥发分、低灰、低硫、低磷、中等热值、反应活性好等特点,是大规模煤化工、煤电气联产优质原料。但准东煤中较高的Na、Ca含量影响锅炉正常运行,限制了准东高钠煤的燃烧利用,目前电厂主要通过掺烧低钠煤方式加以利用。为考察准东煤及其混煤燃烧与结渣特性,在五彩湾电厂采集了准东煤(ZD)和乌东煤(WD)等2种原料煤。采用热重分析仪研究30%、50%和80%等不同配比下混煤燃烧特性,并分析响应配比下煤灰特性变化规律。结果表明,准东煤混煤燃烧的DTG曲线有2个特征峰。随准东煤配比增加,混煤燃烧TG和DTG曲线向低温区移动,DTG曲线特征峰更明显;混煤燃烧特征温度逐渐降低,最大燃烧速率与综合燃烧特性指数先降低后升高,混煤灰熔融温度逐渐降低。准东煤相对乌东煤具有较高的碱性氧化物和较低的酸性氧化物含量,准东煤配比越高相应的SO3、CaO、Na2O的含量越高结渣倾向性更强。但部分指标并不能准确预测结渣强弱,如准东煤硅铝比为1.67,而乌东煤硅铝比为3.02,依据硅铝比判断结渣倾向性与事实不吻合。另外,煤中CaO含量大于30%后继续增加则灰熔融温度升高,是准东煤比乌东煤具有更高灰熔融温度的原因,随准东煤配比增加,混煤灰熔融温度呈明显降低趋势。燃烧结渣与沾污倾向指标主要有基于煤灰成分和基于煤灰熔融温度的指标,总结分析以往结渣与沾污预测指标结合试验结果认为:基于煤灰成分的碱酸比以及基于煤灰熔融温度的特征温度差值(FT-DT)是判别准东煤及其混煤结渣与沾污倾向性的理想指标。
Zhundong coalfield is the largest integrated basin in China.Combined with the characteristics of medium and high water content,medium and high volatile matter,low contents of sulfur,trace element,and low cost mining,medium calorific value and good reaction activity,which is a large-scale coal chemical industry and coal electrical co production high-quality raw material.However,the high content of Na and Ca in Zhundong coal affects the normal operation of the boiler,which limits the combustion and utilization of Zhundong high sodium coal.To investigate the combustion and slagging characteristics of Zhundong coal and its mixture,two raw coal called Zhundong coal(ZD)and Wudong coal(WD)were collected from Wuhuaiwan power plant.The combustion characteristics of ZD coal and mixed coals were studied using thermogravimetric analyzer,and the change rule of coal ash characteristics under response ratio was analyzed.The results show that there are two characteristic peaks for blendings of Zhundong and Wudong coals.With the increase of ZD coal blending ratio,TD-DTG curves of blended coal combustion move to the low temperature area,and the characteristic peak of DTG curve is more obvious.The characteristic temperature and the ash fusion temperature of blended coals gradually decrease,while the maximum combustion rate and comprehensive combustion characteristic index first decrease and then increase,and the fusion temperature of blended coal ash gradually decreases.ZD coal has higher alkali oxide and lower acid oxide content than WD coal,and blending with high ratio zhundong coal has high contents of SO3,CaO and Na2O and more serious ash-related problems;However,some indexes can not accurately predict the slagging strength,such as Zhundong coal silicon aluminum ratio is 1.67,and Wudong coal silicon aluminum ratio is 3.02.Judging slagging tendency based on silicon aluminum ratio is not consistent with the fact;In addition,when the CaO content in coal is more than 30%,the ash melting temperature will increase,which is the reason
作者
白杨
赵勇纲
徐会军
朱川
BAI Yang;ZHAO Yonggang;XU Huijun;ZHU Chuan(Shenhua Guoshen Technical Research Institute,Xi′an 710065,China;CHN Energy Co.,Ltd.,Beijing 100011,China;Coal Chemistry Branch of China Coal Research Institute,Beijing 100013,China)
出处
《洁净煤技术》
CAS
2019年第6期132-138,共7页
Clean Coal Technology
基金
国家科技支撑计划资助项目(2015BAA04B02)
关键词
高碱煤
煤灰熔融温度
混煤
结渣与沾污
high alkali coal
ash fusion temperature
blendedcoal
slag and fouling
