350 MW超临界循环流化床锅炉SO_(2)、NO_(x)及粉尘排放特性试验  

Emission characteristics test of SO_(2),NO_(x) and dust from a 350 MW super-critical circulating fluidized bed boiler

作　　者：元泽民 黄中[2] 武广剑 杨云凯 杨海瑞[2] 赵贯甲[1] 岳光溪[2] 马素霞[1] YUAN Zemin;HUANG Zhong;WU Guangjian;YANG Yunkai;YANG Hairui;ZHAO Guanjia;YUE Guangxi;MA Suxia(Key Laboratory of Clean and Efficient Combustion and Utilization in the Circulating Fluidized Bed,Taiyuan University of Technology,Taiyuan 030024,China;Department of Energy and Power Engineering,Tsinghua University,Beijing 100084,China;Jinneng Datuhe Power Plant Co.,Ltd.,Lyuliang 033000,China)

机构地区：[1]太原理工大学循环流化床高效清洁燃烧与利用山西省重点实验室,山西太原030024 [2]清华大学能源与动力工程系,北京100084 [3]晋能大土河热电有限公司,山西吕梁033000

出　　处：《洁净煤技术》2023年第2期163-171,共9页Clean Coal Technology

基　　金：国家重点研发计划资助项目(2020YFB0606303)。

摘　　要：为了解煤泥、煤矸石等多元低热值煤掺烧下CFB锅炉污染物生成排放特性,以某电厂350 MW超临界CFB锅炉为研究对象,基于现场运行实测数据,研究了该锅炉在30%~99%负荷率下烟气SO_(2)、NO_(x)生成及粉尘排放随负荷变化的特性,并分析了锅炉运行负荷、平均床温、过量空气系数及流化风率等关键运行参数对其生成与排放水平的影响。试验结果表明,该机组在30%~99%全负荷条件下总排放口烟气污染物排放均能够满足超低排放标准;SO_(2)、NO_(x)排放浓度随锅炉负荷的降低基本呈现先降低后迅速升高的趋势,粉尘排放浓度随锅炉负荷的降低而降低;所研究关键运行参数中,锅炉床温对SO_(2)、NO_(x)生成与排放水平起主导作用;低负荷下锅炉平均床温较低、炉膛过量空气系数较大,SO_(2)、NO_(x)生成浓度偏高,且二者排放浓度与过量空气系数及流化风率基本呈正相关。综合考虑,应适当控制锅炉平均床温在800℃以上,过量空气系数应不高于1.3为宜;低负荷下可采取烟气再循环措施来降低烟气含氧量,同时维持物料正常流化。To master the pollutant emission characteristics of a 350 MW supercritical CFB boiler under mixed combustion of multi-element low-calorific value coal including coal slime and coal gangue,taking a 350 MW supercritical CFB boiler of a power plant as the research object,and based on the measured data of on-site operation,the formation and emission characteristics of SO_(2),NO_(x) and dust in flue gas were studied against the boiler load rate between 30%and 99%.Additionally,the key operated parameters including boiler operating load,average bed temperature,excess air coefficient and fluidizing air rate on its generation and emission level were investigated.The test results reveal that the flue gas pollutant emissions of the CFB unit can meet the emission standards within the load range of 30%-99%at total discharge outlet.The emission concentration of SO_(2),NO_(x) basically decreases first and then increases rapidly with the decrease of boiler load.The concentration of dust emission decreases with the decrease of boiler load,and the dust emission concentration decreases with the reduction of boiler load.Among the key operating parameters studied,the boiler bed temperature plays a leading role in the emis⁃sion level of SO_(2),NO_(x).The emission concentration of SO_(2) and NO_(x) is higher with the lower average bed temperature and the larger excess air coefficient,and the emission concentration is basically positively correlated with the excess air coefficient and fluidization air rate.Con⁃sidering comprehensively,it is recommended that the average bed temperature of the boiler should be properly controlled above 800℃,and the excess air coefficient should be stabilized less than 1.3.The way of flue gas recirculation can be used to reduce the oxygen concen⁃tration of the flue gas under low load on the basis of the maintaining the normal fluidization of the material.

关 键 词：超临界循环流化床锅炉 SO_(2) NO_(x) 床温 粉尘排放特性 

分 类 号：TK16[动力工程及工程热物理—热能工程]