SCR脱硝装置对锅炉内爆影响的数值模拟  

Numerical Simulation of Influence of SCR Denitration Reactor on Furnace Implosion

作　　者：程星星[1] 金保升[1] 钟文琪[1] 仲兆平[1] 

机构地区：[1]东南大学能源与环境学院,南京210096

出　　处：《燃烧科学与技术》2009年第6期551-556,共6页Journal of Combustion Science and Technology

摘　　要：建立了包括炉膛、省煤器、SCR脱硝装置、空气预热器、除尘器和引风机等的锅炉全系统三维非稳态数值模型.对烟道内的传热采用换热器模型,换热效率采用NTU方法,用简化的二次函数模拟误操作时引风机的特性曲线.模拟结果和锅炉设计参数吻合较好.分别对有无SCR脱硝装置的系统进行内爆模拟,分析指出内爆是引风机误操作时导致的负压源增大、烟道烟气流量减小引起的减压阻力减小、进风口压力补充的消失、炉膛本身烟气生成量的突减等因素共同作用的结果.引风机的作用只占内爆成因的一部分,SCR脱硝装置引起的内爆强度增大值仅为1 kPa左右,消除了加装SCR脱硝装置可能会大幅度增大内爆强度的疑虑.Numerical simulation of 300 MW pulverized coal boiler, including furnace, super-heater, economizer, SCR denitration reactor air pre-heater and EPS, was conducted.. Exchanger model was used as heat exchanging process in the fine duct, and heat-exchanging efficiency was defined by NTU methods. ID fan was regarded as a thin wall with its operation characteristics defined by a simplified function. The simulation result agrees well with the designed value. Then dynamic simulation was conducted on systems with and without SCR denitration reactor, respectively. Based on the results, it is pointed out that implosion results from the combined factors, among which are increasing of ID fan head, decreasing of flue gas mass flow rate, disappearing of inlet air and diminishing of gas formation. Implosion pressure increases by only about 1 kPa after installation of SCR denitration reactor, since ID fan only accounts partly for furnace low pressure. Such results can remove the uncertainly about whether SCR denitration reactor will lead to increased furnace implosion.

关 键 词：选择性催化还原 锅炉内爆 数值模拟 

分 类 号：TK223.6[动力工程及工程热物理—动力机械及工程]