摘要
电站锅炉烟气余热深度回收及烟气脱水是提高机组热效率、降低水耗率的重要途径之一。本文以某亚临界330 MW机组为对象,提出了烟气余热深度利用与烟气脱水的系统流程,研究了余热利用系统与回热系统的集成方案,基于等效焓降法计算了各方案的热力性能,并对关键参数进行了敏感性分析。结果表明:利用氟塑料烟气余热换热器(FGC1)和烟气脱水换热器(FGC2)可实现烟气余热的深度回收及水分的脱除,降低了机组的发电煤耗率和水耗率;闭式水互联的串并联集成方案d性能最优,设计工况下可节约发电标准煤耗率3.03 g/(k W?h),回收冷凝水5.7 t/h;随着FGC1出口烟气温度的下降,煤耗率增加,但其换热面积也增加,当烟气温度一定时,方案d所需换热面积最小。
Waste heat and water recovery from flue gas in utility boilers is important way to improve thermal efficiency and decrease water consumption rate of unit.Taking a 330 MW subcritical unit as a research object,this paper proposes a system flow of waste heat and water recovery from flue gas,and studies the integrated scheme of waste heat recovery system and heat regenerative system.Thermodynamic performances of the schemes are calculated based on the equivalent enthalpy drop method,and the sensitivity analyses of key parameters are conducted.The results show that flue gas waste heat recovery exchanger bundled by polytetrafluoroethylene tube(FGC1)and dewatering heat exchanger(FGC2)can recycle heat and water respectively,and decrease coal consumption rate of power generation and water consumption rate of unit.The series-parallel integrated scheme d has the optimal performance,the scheme can save standard coal consumption rate at 3.03 g/(kW?h)and recycle water at 5.7 t/h under design conditions.With the drop of flue gas temperature at FGC1 exit enhances,coal consumption rate increases,and the heat transfer area is also increasing.For a certain flue gas temperature,the scheme d requires minimum heat transfer area.
作者
王金平
安连锁
张学镭
WANG Jinping;AN Liansuo;ZHANG Xuelei(School of Energy,Power and Mechanical Engineering,North China Electric Power University,Beijing 102206,China;China Guodian Corporation,Beijing 100034,China)
出处
《热力发电》
CAS
北大核心
2018年第4期48-54,共7页
Thermal Power Generation
基金
国家科技支撑计划项目(2012BAA07B01)~~
关键词
锅炉
排烟温度
余热回收
烟气脱水
回热系统
换热器
煤耗率
水耗率
boiler
exhaust gas temperature
waste heat recovery
water recovery from flue gas
heat regenerative system
heat exchanger
coal consumption rate
water consumption rate
