【作者】 李培；

【导师】 杨建国； 赵虹； 周永刚；

【作者基本信息】 浙江大学 ， 工程热物理， 2011， 硕士

【摘要】 我国蒙东地区贮藏有丰富的褐煤资源,由于全水分高达30%以上,Qnet,ar不到3500kcal/kg,影响了长距离运输的经济性和电厂燃用的经济性。由于世界能源危机和国内煤炭紧缺,很多电厂纷纷采购褐煤,以掺烧的方式代替部分烟煤。因此采用经济有效的方法脱除褐煤的水分,扩大褐煤经济利用范围具有重大意义。褐煤热压脱水是在一定的温度和压力下对褐煤进行加热加压,以模拟成煤过程,从而改变褐煤内部结构,脱除煤中水分,增加发热量,使褐煤的物性趋向于烟煤。由于该脱水方法在一定的压力下进行,煤中水分以液态形式脱除,因此能耗较低。此外由于采用热压对褐煤进行改质,可以有效抑制褐煤脱水后的再回水作用,因此具有良好的应用前景。本文针对褐煤热压脱水技术,搭建脱水试验台,并通过热分析等试验方法确定脱水工况,对我国蒙东大雁褐煤在不同压力下热压脱水,得到脱水后褐煤。褐煤的水分有明显程度的下降,全水分仅为原褐煤的25%左右,收到基发热量增加35%-40%。热压后褐煤的回水有一定的抑制。通过电镜扫描和低温氮吸附研究热压脱水前后褐煤的外表面形态和孔隙结构,褐煤热压后表面光滑且孔体积变小。通过对理论经济性分析得到脱水后褐煤的运输经济性和电厂经济性有很大的提高。更多还原

【Abstract】 Lignite resource which is plenty stored in the east of Inner-Mongolia cannot be economically used by long distance transportation and economically and safely used in power plants due to its high moisture as well as low heat value. But as the world energy crisis and domestic coal shortage, each of big power plant purchases lignite to instead of bituminous by the method of blending. So it is significantly to expand the economy utilization area by dewatering the moisture of the lignite by economy and effective method.Lignite thermal-pressure dewatering means to simulate the coal-forming process, in specific temperature and pressure, the internal structure of lignite changes and the moisture decreases, the characteristics of lignite approaches bituminous as its heat value increases. Due to the dewatering process is under high pressure, the moisture in lignite separates out in liquid, so that the energy consumption relatively lower. Furthermore, this dewatering method has good application prosperity because the dewatered lignite has restraint effective to water re-absorption.This thesis in connection with thermal-pressure dewatering technical, determined the work condition for dewatering by thermal analysis and et al. dewatered lignite can be getted by thermal-pressure the Dayan lignite form east of the Inner-Mongolia through experimental bench. The moisture in lignite decreases significantly under different pressure dewatering. The total moisture decreased by 75% and the heat value increased by 25%. The thermal-pressure dewatering has certain effective in restraint its water re-absorption. Used SEM to analysis thermal-pressure dewatered lignite, the surface of dewatered lignite got smooth and the gully structure disappeared. The low-temperature nitrogen absorption test shows the pore size distribution dewatered under higher pressure changed and the total pore volume decreased. The dewatered lignite shows its’economic in long transportation and power plants combustion.更多还原