摘要
基于某1000 MW高效超超临界机组锅炉,针对大容量、高参数燃煤锅炉尾部烟气余热利用技术进行系统性分析,提出了一种机炉深度耦合的先进余热利用系统方案。在空预器入口烟道处引出20%份额旁路烟道,旁路烟道中布置烟气换热器来加热锅炉给水和凝结水,同时在除尘器前烟道内布置烟气-热媒水换热器,烟气余热通过热媒水传递给空预器入口冷风和凝结水。通过系统方案的实施,30%THA下冷二次风、排烟温度分别由25℃、106℃提升至100℃、129℃,克服了空预器低负荷下冷端腐蚀的问题,同时实现了锅炉烟气余热的梯级利用,汽机抽汽明显减少,电厂经济性显著提高,可为其他同类型机组余热利用方案提供借鉴。
Based on a 1000 MW high-efficiency USC boiler,this paper systematically analyzes the waste heat utilization technology of tail flue gas of large capacity and high parameter coal-fired boiler,and puts forward an advanced waste heat utilization system scheme with deep coupling of turbine and boiler.In this scheme,a 20%share bypass flue is led out from the inlet flue of the air preheater.A flue gas heat exchanger is arranged in the bypass flue to heat the boiler feed water and condensate.At the same time,a flue gas heat medium water heat exchanger is arranged in the flue in front of the dust collector.The waste heat of the flue gas is transmitted to the cold air and condensate at the inlet of the air preheater through the heat medium water.Through the implementation of this system scheme,the cooling secondary air and exhaust gas temperatures under 30%tha are increased from 25℃and 106℃to 100℃and 129℃respectively,which overcomes the problem of cold end corrosion of air preheater under low load.At the same time,the cascade utilization of boiler flue gas waste heat is realized,the steam extraction of steam turbine is significantly reduced,and the economy of power plant is significantly improved,which can provide reference experience for waste heat utilization schemes of other similar units.
作者
唐虎震
黎懋亮
曾令午
TANG Huzhen;LI Maoliang;ZENG Lingwu(SuNeng(XILINGOL)Power Generation Co.Ltd,Xilingol 027299,China;Dongfang Boiler Group Co.,Ltd.,Zigong 643001,China;Clean Combustion and Flue Gas Purification Key Laboratory of Sichuan Province,Chengdu 611731,China)
出处
《技术与市场》
2022年第12期12-16,21,共6页
Technology and Market
