降低CFB锅炉NOx初始浓度的方法及其对燃烧性能的影响  

Methods to reduce initial NOx concentration and the effect on combustion performance in CFB boilers

作　　者：卢伟 王西伦 苏岳亮 寇天一 LU Wei;WANG Xilun;SU Yueliang;KOU Tianyi(China Energy Suzhou Thermal Power Plant Co.,Ltd.,Suzhou 23400,China;Yantai Longyuan Power Technology Co.,Ltd.,Yantai 264006,China;China Energy Tongling Thermal Power Plant Co.,Ltd.,Tongling 244100,China)

机构地区：[1]国能宿州热电有限公司,安徽宿州234000 [2]烟台龙源电力技术股份有限公司,山东烟台264006 [3]国能铜陵发电有限公司,安徽铜陵244100

出　　处：《电力科技与环保》2022年第4期333-338,共6页Electric Power Technology and Environmental Protection

基　　金：国家能源投资集团有限责任公司科技项目(GJNY-21-168)。

摘　　要：为了进一步降低CFB锅炉NO_(x)初始浓度,以某电厂300MW亚临界循环流化床锅炉为例,在不对设备进行改造的前提下,利用调试手段对二次风母管压力、钙硫比以及床温等参数进行调整,同时结合二次风喷口差异化配风和差异化给煤等手段,对锅炉污染物排放与燃尽特性进行深入研究,旨在充分发挥现有设备潜能,降低NO_(x)初始浓度,为未来超低排放降低成本提供可靠依据。燃烧调整试验结果表明:(1)300MW负荷时,二次风母管风压由7kPa提升至10kPa时,炉膛出口NO_(x)初始浓度由250mg/m^(3)降至200mg/m^(3),NO_(x)浓度可降低50mg/m^(3);飞灰可燃物由4.74%降至3.41%,飞灰可燃物可降低1.32%;炉渣可燃物由1.82%降至1.49%,炉渣可燃物可降低0.33%;(2)300MW负荷,床温为900、925℃,940℃时,炉膛出口NO_(x)初始浓度分别为98mg/m^(3)、113mg/m^(3)、192mg/m^(3),床温在925℃时是NO_(x)急剧生成的拐点;(3)二次风母管压力在10kPa左右可保证煤颗粒具有更好的燃尽特性。在此基础上对大型循环流化床锅炉进行NO_(x)超低排放改造,在降低喷氨量的前提下,不仅可以有效降低改造设备投资成本,还可以在一定程度上降低燃料消耗量,经济效益显著。To further reduce initial NO_(x) concentration in CFB boilers,this paper takes 300MW subcritical CFB boiler as an example.On the premise of no equipment modification,using the debugging method of secondary air mother pipe pressure,calcium sulfur ratio and adjust parameters,such as bed temperature.At the same time,combining with the secondary air nozzle differentiation,air distribution and differentiation to coal for boiler emissions and burnout characteristics in-depth research.It aims to give full play to the potential of existing equipment,reduce the initial emission concentration of NO_(x),and provide a reliable basis for ultra-low emission cost reduction in the future.The results of the combustion adjustment test show that(1)at 300MW load,when the pressure of the secondary air master pipe is increased from 7kPa to 10kPa,the NO_(x) initial concentration at the outlet of furnace is reduced from 250mg/m^(3) to 200mg/m^(3),reduced by 50mg/m^(3).Fly ash combustibles can be reduced from 4.74%to 3.41%,reduced by 1.33%.The slag combustibles can be reduced from 1.82%to 1.49%,reduced by 0.32%.(2)At 300MW load,bed temperature of 900℃,925℃,940℃,furnace outlet NO_(x) initial concentrations is 98mg/m^(3),113mg/m^(3),192mg/m^(3),the inflection point of NO_(x) formation is 925℃.(3)The secondary air main pipe pressure of about 10KPa can ensure that coal particles have better burnout characteristics.On this basis to carry out ultra-low NO_(x) emission transformation of large circulating fluidized bed boiler,on the premise of reducing the amount of ammonia injection,it cannot only effectively reduce the investment cost of transformation equipment,but also reduce fuel consumption to a certain extent with significant economic benefits.

关 键 词：CFB 燃烧调整 Ca/S 床温 二次风 低NOX排放 

分 类 号：TK229[动力工程及工程热物理—动力机械及工程] X701.7[环境科学与工程—环境工程]