大型燃气锅炉烟气冷凝余热深度回收技术方案与节能潜力分析

Technical scheme and energy-saving potential analysis of flue gas condensing heat deep-recovery in large gas-fired boilers

针对大型燃气锅炉排烟温度高、能耗高、排放量大等问题,结合烟气余热深度利用中遇到的锅炉房空间小,需要的热回收设备大、阻力大、造价高,节能改造资金紧张等问题,提出了不同的燃气锅炉烟气冷凝余热深度回收利用技术方案,以减小设备体积、阻力,减少成本。北方某既有大型燃气锅炉改造工程的节能分析结果表明：排烟温度由160℃降至30-50℃,节能10%-13%;单台锅炉（70MW）回收烟气冷凝水70-160t/d,除水率达27%-60%,减少了雾气排放量,减排二氧化碳和氮氧化物10%以上。

Focusing on the problems of the high exhaust gas temperature,high energy consumption and huge emissions of large gas-fired boilers,as well as others such as limit space,huge heat recovery equipment,high resistance,high investment and energy saving reconstruction funds constraint in the deep utilization of the flue gas waste heat,puts forward different technical schemes of the gas-fired boiler flue gas condensing heat deep-recovery.Energy-saving analysis results for an existing large gas-fired boiler reconstruction project in the north of China show that the exhaust temperature can be reduced from 160℃to 30-50 ℃,with energy-saving rate up to 10%-13%,and one boiler can produce flue gas condensate water of 70-160 tons per day,with drainage rate of 27%-60%,fog emissions being reduced and carbon dioxide and nitrogen oxide exhaust being decreased more than 10%.