1000MW超超临界单炉膛双切圆锅炉水冷壁贴壁气氛影响因素  

Influence factors of reductive atmosphere close to water wall of an 1000 MW ultra-supercritical boiler with single chamber and dual tangential

作　　者：刘同干 刘晓东 何利军 戴维葆 孔俊峰 陈国庆 戴家麒 马江英 LIU Tonggan;LIU Xiaodong;HE Lijun;DAI Weibao;KONG Junfeng;CHEN Guoqing;DAI Jiaqi;MA Jiangying(CHN Energy Taizhou Power Generation Co.,Ltd.,Taizhou 225327,China;Guodian Nanjing Electric Test Research Co.,Ltd.,Nanjing 210023,China)

机构地区：[1]国家能源集团泰州发电有限公司,江苏泰州225327 [2]国电南京电力试验研究有限公司,江苏南京210023

出　　处：《洁净煤技术》2021年第6期100-107,共8页Clean Coal Technology

基　　金：国家能源集团科技资助项目(GJNY-19-84)。

摘　　要：为了研究影响单炉膛双切圆锅炉水冷壁贴壁气氛变化的因素,以某电厂超超临界1000 MW燃煤机组单炉膛双切圆燃烧方式锅炉为研究对象,基于现场试验,通过测量不同负荷和不同运行参数下锅炉水冷壁近壁区烟气成分(O_(2)、CO和H_(2)S),研究机组负荷、运行氧量、分离燃尽风风量、煤粉细度等因素对水冷壁贴壁气氛中O_(2)、CO和H_(2)S体积分数的影响。结果表明,热角位置(2、3、5、8号角)还原性气氛较强,中高负荷下,热角位置O_(2)体积分数基本为0,CO体积分数超过50000×10^(-6),热角位置发生高温腐蚀的可能性大;低负荷下,热角位置可测量到不同浓度的O_(2),CO体积分数降低到30000×10^(-6),仅有局部位置存在高温腐蚀的可能;随着炉膛高度的增大,贴壁气氛的还原性逐渐增强,第3层热角位置贴壁气氛还原性最强;机组负荷越高,贴壁还原性气氛越强,负荷由50%BRL向75%BRL转变过程中,热角位置贴壁气氛中O_(2)体积分数迅速下降,CO体积分数迅速升高,还原性气氛急剧增强;适当提高运行氧量,减少燃尽风量,可以提高主燃区的过剩空气系数,贴壁气氛中CO体积分数下降,还原性强度减弱;降低煤粉细度,有利于煤粉的着火和燃烧,贴壁气氛中CO体积分数下降,可在一定程度上减弱贴壁气氛的还原性强度。燃烧调整可以缓解贴壁气氛还原性强度,并不能从根本上解决高温腐蚀问题。In order to study the influence factors on the atmosphere close to water wall of boiler with single chamber and dual tangential,an ultra-supercritical 1000 MW boiler with single chamber and dual tangential circle was taken as the research object.Experimental tests were carried out to measure the flue gas composition(O_(2),CO and H_(2)S)in the area close to water wall under different loads and different operational conditions,so as to analyze the effects of unit load,operating oxygen,separated over-fired air(SOFA)flow rate,fineness of pulverized coal on the O_(2),CO and H_(2)S concentration close to water wall.The results show that the areas close to burners 2,3,5 and 8 have the relative stronger reductive atmosphere,so as to called hot corners.The O_(2) concentration is basically 0 and the CO concentration is more than 50000×10^(-6) under medium and high load in the hot corners,which have big possibility of high temperature corrosion.Under low load,different concentration of O_(2) can be measured at the hot corners,and the CO concentration is more than 30000×10^(-6),so that just some local positions have possibility of high temperature corrosion.With the increase of furnace height,the reductive atmosphere gradually increases.The third layer has the strongest reduction of the atmosphere near the wall at the hot angle.The higher the unit load,the stronger the reductive atmosphere.The O_(2) concentration reduces and the CO concentration increases rapidly,and the reducing atmosphere increased sharply when the load increases from 50%BRL to 75%BRL.The reductive atmosphere can be decreased to a certain extent through appropriate increase of operating oxygen or regulation of the SOFA rate,for the excess air number becomes bigger.It is benefit of ignition and combustion of pulverized coal with the reducing the fineness of pulverized coal.The volume fraction of CO in the wall atmosphere decreases,which can weaken the reductive strength of the wall atmosphere to a certain extent.Combustion adjustment can alleviate the red

关 键 词：燃煤锅炉 单炉膛双切圆 高温腐蚀 贴壁气氛 热角 

分 类 号：TQ53[化学工程—煤化学工程] TK114[动力工程及工程热物理—热能工程]