摘要
采用加压/常压富氧燃烧循环流化床技术时,随着炉膛入口平均氧浓度和压力的升高,烟气体积不断减小,为确保一定的炉膛空截面烟气速度,炉膛横截面积需相应减小,导致炉膛布置受热面的空间减小,使炉膛温度控制的问题更加突出;同时,若锅炉各受热面的布置方式不当,也会导致部分受热面的传热温差不合理,不利于锅炉的初投资和正常运行。文中进行75t/h工业规模加压/常压富氧燃烧循环流化床锅炉的方案设计,提出富氧燃烧条件下循环流化床锅炉灰平衡和烟气成分的计算方法,着重分析炉膛入口平均氧浓度和压力对烟气循环倍率、锅炉结构、外置式换热器布置和锅炉各受热面吸热量分配等的影响规律。在加压/常压富氧燃烧条件下,随着炉膛入口平均氧浓度和压力的升高,可通过拔高炉膛、增设外置式换热器、屏式过热器等对锅炉各受热面吸热份额进行调整,使锅炉各受热面均在合理的参数范围内运行。
When pressurized/atmospheric circulating fluidized bed oxy-fuel combustion technology was used and a certain furnace cross-section speed was ensured,with the increase of the average oxygen concentration and pressure at the furnace inlet,the flue gas volume and the cross-sectional area of the furnace decreased,which led to the reduction of the space of the heating surface arranged in the furnace,and the problem of furnace temperature control was prominent.Meanwhile,if the layout of each heating surface of the boiler was improperly arranged,it also led to the unreasonable heat transfer temperature,which was not conducive to the initial investment and normal operation of the boiler.In order to analyze the influence of oxygen concentration and pressure on flue gas circulation ratio,boiler structure,external heat exchanger(EHE)and heat absorption distribution on boiler heating surfaces,the design of 75t/h industrial scale pressurized/atmospheric oxy-fuel combustion circulating fluidized bed boiler was carried out,and the calculation method of ash balance and flue gas composition of circulating fluidized bed boiler under oxy-fuel combustion conditions was proposed.Under the condition of pressurized/atmospheric oxy-fuel combustion,with the increase of the average oxygen concentration and pressure at the furnace inlet,the heat absorption share of each heating surface of the boiler can be adjusted by pulling out the furnace,adding external heat exchanger,platen superheater,etc,so that each heating surface of the boiler can be operated within the reasonable parameter range.
作者
郑东
陈晓平
马吉亮
刘道银
梁财
ZHENG Dong;CHEN Xiaoping;MA Jiliang;LIU Daoyin;LIANG Cai(Key Laboratory of Thermal Energy Conversion and Control of Ministry of Education(Southeast University),Nanjing 210096,Jiangsu Province,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2020年第13期4226-4235,共10页
Proceedings of the CSEE
基金
国家重点研发计划(2016YFB0600800)。
关键词
加压/常压富氧燃烧
循环流化床锅炉
外置式换热器
CO2捕集
烟气再循环
pressurized/atmospheric oxy-fuel combustion
circulating fluidized bed (CFB)
external heat exchanger
CO2 capture
flue gas recirculation
