【作者】 崔福兴；

【导师】 赵虹； 杨建国；

【作者基本信息】 浙江大学 ， 工程热物理， 2010， 硕士

【摘要】 能源的短缺是制约人类社会发展的重大问题,我国目前积极推进节能降耗工程建设,落实节约资源基本国策。火电厂是耗煤大户,充分挖掘火电厂节能降耗潜力,对推动我国的节能事业、促进社会可持续发展有着重要的实际意义。锅炉排烟热损失是锅炉系统最大的热损失,降低排烟热损失可以充分利用煤炭资源,达到节能降耗的目的。本文立足于研究提高中速磨煤机出口温度的可行性,确定出燃烧实际煤种安全运行时能承受的最高磨煤机进口热空气温度,最大限度的利用空预器中烟气换热量,降低排烟热损失,提高锅炉运行经济性。实际运行时规定了中速磨煤机最高出口温度,这是为了防止进口热空气温度过高而导致制粉系统运行安全性降低,这牺牲了系统经济性。从理论上说,不同的煤对应着不同的最高且安全的磨煤机进口温度,如何从实验室出发,找出实际煤种的最高承受温度,是本文要解决的问题。利用TG-FTIR技术可以确定煤中可燃气体在不同气氛下的析出情况。一般中速磨煤机磨制挥发分较大的烟煤、次烟煤及褐煤,其主要析出可燃气体为CO,本文通过TG-FTIR分析N2、air气氛下CO的析出情况,确定CO开始析出温度,并将此温度认定为该煤种可承受的最高热空气温度,分析了CO开始析出温度与Vdaf的关系,并从机理上对CO析出情况进行阐述。实验室确定出实际煤种的最高进口热空气温度,通过理论计算验证了温州电厂燃烧富动24时干燥出力满足磨煤机出口温度提高至95℃的工况,在温州电厂300MW机组上进行了提高中速磨煤机出口温度的现场试验,得出一系列锅炉参数随磨煤机出口温度变化的情况,试验期间制粉系统运行安全,磨煤机内部无CO析出,锅炉排烟温度下降7℃左右,锅炉热效率提高了0.37%,有较好的经济效益。更多还原

【Abstract】 The lack of energy impedes advance of society, so far authority took action to carry out Energy conservation and cost reduction projects. Thermal power plant is the largest coal consumer in China, so it is highly significant to develop cost reduction projects.Exhaust gas loss (q2) is the biggest loss in boiler, so if we can decrease q2, coal can be used less.The paper deeply analysed the feasibility of increasing medium-speed pulverizer outlet temperature, then found the maximum pulverizer inlet hot air temperature when boiler run safely, then decreased q2 and raised thermal efficiency of boiler.Generally, operation regulations set rules about pulverizer outlet temperature to assure system running safely; always it leads to energy waste. Theoretically, a coal corresponds to a safe and maximum pulverizer inlet hot air temperature, so this paper worked at how to get the optimum temperature.TG-FTIR can make sure how CO Separated from coal.Generally medium-speed pulverizer can mill bituminous coal、subbituminous and brown coal,these coals contains a lot of O,therefore the flammable gas from coals always is CO,the paper analysed CO separation from coal under conditions of N2 or air by TG-FTIR,then defined CO first generated temperature.This temperature was defined to be the safe and maximum pulverizer inlet hot air temperature, and analysed the relationship between CO and Vdaf.Field test of Improving medium-speed pulverizer outlet temperature began in 300WM wenzhou Thermal power plant, during test the Coal Preparation System ran safely,and there was no CO generated in pulverizer, and exhaust temperature decreased 7℃,and the thermal efficiency of boiler raised 0.37%.更多还原