摘要
褐煤干燥脱水是实现其高效利用、节能减排的重要技术措施。基于不同热风温度(60℃,80℃,100℃)和煤样粒度(小于2 mm,2 mm~5 mm,5 mm~7 mm,7 mm~10 mm,10 mm~13 mm)对高西沟低阶褐煤单一热风干燥特性进行探讨,依次采用单一热风干燥、热风-红外串联和热风-红外并联联合干燥方式,通过实验分析了干燥过程褐煤水分比和干燥速率的变化特征,应用比能耗(QSEC)和能效(ηe)对比了三种干燥方式的能耗,采用SEM和FTIR分别分析了煤样表观形貌和官能团。结果表明:单一热风干燥温度越高,煤样与空气温差越大,煤样获得的热量越高,干燥速率越快;煤样粒度越小,煤样水分比下降越快,结束时的水分比越低;热风-红外串联联合干燥转换时间节点越早,所需干燥时间越短,在热风与红外干燥阶段干燥速率各出现一次最大值;并联干燥中褐煤水分比呈指数下降,并以降速期为主要阶段;三种干燥方式按比能耗由大到小依次为单一热风干燥(334.54 MJ/kg)、热风-红外并联干燥(273.89 MJ/kg)、热风-红外串联干燥(121.18 MJ/kg),按能效(ηe)由大到小依次为热风-红外串联干燥(1.91%)、热风-红外并联干燥(0.83%)、单一热风干燥(0.69%),热风-红外串联干燥为较节能的干燥方式,此方式干燥后煤样相较原褐煤表面大面积坍塌,表面裂隙明显增多、增大,并且干燥煤样除水分外的其他官能团未发生变化。
Lignite drying and dehydration is an important technical measure to achieve its efficient utilization,energy saving,and emission reduction.The influences of different temperatures(60℃,80℃,100℃)and coal particle sizes(<2 mm,2 mm-5 mm,5 mm-7 mm,7 mm-10 mm,10 mm-13 mm)on drying characteristics of low-rank lignite from Gaoxigou using the hot-air drying method were investigated.Then the experiments were sequentially conducted under the same hot-air temperature and coal particle size using the hot-air in series with infrared drying method and the hot-air in parallel with the infrared drying method.The variation characteristics of lignite moisture ratio and drying rate during the drying process were analyzed by experiments.The specific energy consumption Q SEC and energy efficiencyηe were used to compare the energy consumption of three drying methods.The apparent morphology and functional groups of coal samples were analyzed by SEM and FTIR,respectively.The results show that the higher the hot-air temperature,the higher the temperature difference between the coal sample and air,the higher the heat obtained by the coal sample,and the faster the drying rate.The smaller the coal particle size,the faster the moisture ratio dropped and the lower the moisture ratio at the end of the drying process.The earlier the time of the conversion between hot-air drying and infrared drying,the shorter the required drying time,and the drying rate appeares a maximum once in each of the stages of the hot-air and the infrared drying.In parallel drying,the moisture ratio of lignite decreases exponentially,with the main stage being the decreasing rate period.The specific energy consumption Q SEC value for the hot-air drying method is 334.54 MJ/kg,higher than 273.89 MJ/kg of the hot-air in parallel with the infrared drying method,and the 121.18 MJ/kg of the hot-air in series with infrared drying method is the smallest.The energy efficiencyηe value for the hot-air in series with infrared drying method is 1.91%,higher than 0.83%for the ho
作者
牛婷婷
薛韩玲
陆泽华
王楠
拓雯
杨志远
苗宇
NIU Tingting;XUE Hanling;LU Zehua;WANG Nan;TUO Wen;YANG Zhiyuan;MIAO Yu(College of Energy Science and Engineering,Xi’an University of Science and Technology,710054 Xi’an,China;College of Civil and Architectural Engineering,Xi’an University of Science and Technology,710054 Xi’an,China;College of Chemistry and Chemical Engineering,Xi’an University of Science and Technology,710054 Xi’an,China;Huaihe Energy(Group)Company Limited,232000 Huainan,China)
出处
《煤炭转化》
CAS
CSCD
北大核心
2024年第2期1-11,共11页
Coal Conversion
基金
国家自然科学基金项目(41772166)
陕西省科技统筹重点产业创新链项目(2017ZDCXL-GY-10-1)。
关键词
褐煤
热风-红外联合干燥
能耗
表观形貌
官能团
lignite
hot air combined with infrared drying
energy consumption
morphology
functional group
