烟气再循环对超临界二氧化碳燃煤锅炉传热性能的影响  

Effect of Flue Gas Recirculation on Heat Transfer Performance of a Supercritical Carbon Dioxide Coal-fired Boiler

作　　者：袁峰 陈亮[1] 王春波[1] 戴文浩 YUAN Feng;CHEN Liang;WANG Chunbo;DAI Wenhao(Hebei Key Laboratory of Low Carbon and High Efficiency Power Generation Technology,Department of Power Engineering,North China Electric Power University,Baoding 071003,Hebei Province,China)

机构地区：[1]华北电力大学动力工程系,河北省低碳高效发电技术重点实验室,河北保定071003

出　　处：《动力工程学报》2022年第10期889-896,918,共9页Journal of Chinese Society of Power Engineering

基　　金：国家重点研发计划资助项目(2020YFB0606301);中央高校基本科研业务费资助项目(2020MS101)。

摘　　要：针对某1000MW超临界二氧化碳(S-CO_(2))锅炉,通过建立锅侧燃烧与传热耦合模型,并对冷却壁壁温进行计算分析,提出采用烟气再循环的方案来降低冷却壁壁温,研究了烟气再循环对冷却壁壁温、炉膛出口烟温、排烟温度以及过热器、再热器出口工质温度的影响。针对仅采用烟气再循环方案,会出现炉膛出口烟温降低和排烟温度升高等问题,对S-CO_(2)锅炉进行了优化改造。结果表明:烟气再循环率为20%时,冷却壁壁温最高值从690℃降低至640℃;采用20%烟气再循环方案时,改造后锅炉的排烟温度由143℃降低至123℃,锅炉效率由92.8%提高至94%,壁面区域H_(2)S摩尔分数和CO摩尔分数降低,高温腐蚀速率减少,优化改造后的锅炉采用烟气再循环方案可降低冷却壁壁温。For a 1000MW supercritical carbon dioxide(S-CO_(2))boiler,the cooling wall temperature was calculated and analyzed through the establishment of the boiler side combustion and heat transfer coupling model,and the flue gas recirculation was proposed to reduce the wall temperature.The effects of flue gas recirculation on cooling wall temperature,furnace exit flue gas temperature,exhaust gas temperature and working medium temperature at the outlet of the superheater and reheater were studied.The S-CO_(2)boiler was optimized and reformed for the flue gas temperature at the furnace outlet decreased and the exhaust gas temperature increased while only the flue gas recirculation scheme was adopted.Results show that when the flue gas recirculation rate is 20%,the maximum cooling wall temperature decreases from 690℃to 640℃.When the 20%flue gas recirculation scheme is adopted,the flue gas temperature will be re-duced from 143℃to 123℃,and the boiler thermal efficiency will be increased from 92.8%to 94%.The H_(2)S and CO mole fraction in the wall area decreases and the high-temperature corrosion rate decreases,showing that the flue gas recirculation scheme in the optimized boiler is feasible to reduce the wall tempera-ture.

关 键 词：超临界二氧化碳锅炉 烟气再循环 冷却壁壁温 排烟温度 

分 类 号：TK121[动力工程及工程热物理—工程热物理]