高碱煤富氧燃烧电站系统性能模拟及优化研究  

Performance Modeling and Optimization of Power Station System with Oxy-combustion of the High-alkali Coal

作　　者：张恬 闫凯[2] 乌晓江[2] 周月桂[1] ZHANG Tian;YAN Kai;WU Xiaojiang;ZHOU Yuegui(School of Mechanical and Power Engineering,Shanghai Jiaotong University,Shanghai 200240,China;Shanghai Boiler Works Co.,Ltd.,Shanghai 200245,China)

机构地区：[1]上海交通大学机械与动力工程学院,上海200240 [2]上海锅炉厂有限公司,上海200245

出　　处：《锅炉技术》2018年第6期47-53,共7页Boiler Technology

基　　金：国家自然科学基金资助项目(51576128);上海市青年科技启明星计划资助项目(17QB1400900)

摘　　要：采用Aspen Plus软件对某315 MW亚临界机组富氧燃烧改造前后的热力发电系统进行了全流程模拟,分析了富氧燃烧对电站热经济性的影响。建立了空气及富氧燃烧方式下准东煤燃烧及碱金属迁移转化模型,分析比较不同燃烧方式下Na、K碱金属的赋存、迁移和转化规律。经比较发现富氧煤粉燃烧由于烟气再循环的作用,烟气中碱金属的含量显著增多,锅炉排烟中Na_2SO_4质量分数由空气燃烧排烟的0.045%增加至0.056%。对常规燃煤电站进行富氧燃烧技术改造,其净效率由36. 11%下降至22.75%。但通过系统热集成优化,净效率尚可提高4. 77个百分点,从而降低了CO_2捕集成本。烟气经纯化压缩后使干烟气中CO_2质量分数升高至95. 34%,继而通过捕集封存实现98. 35%的CO_2回收率。The performance of thermal power generation system.of a 315MW subcritical unit before and after Oxygen-coal combustion retrofit was simulated by Aspen Plus,and the influence of Oxy-coal combustion on thermal economy of power station was analyzed.The combustion model of high-alkali coal and alkali metal reacting model under air combustion and Oxy-coal combustion were established,and the occurrence,migration and transformation of Na-K alkali metal in coal under different combustion modes were analyzed and compared.It is found by comparisor/that the content of alkali metal in flue gas increases significantly due to the recirculation of flue gas in the Oxy-coal combustion,especially the mass fraction of Na2SO4 in the exhaust gas of boiler increases from 0.045% to 0.056%.The net efficiency of Oxy-coal combustion plant is reduced from 36.11% to 22.75%,but the net efficiency of Oxycoal combustion plant can be improved by 4.77% by system thermal integration,thus reducing the CO2capture cost.After purification and compression,the mass fraction of CO2 in dry flue gas was increased to 95.34%,and the 98.35% recovery rate of CO2was achieved.

关 键 词：高碱煤 富氧燃烧 碱金属迁移 系统建模 集成优化 

分 类 号：TK114[动力工程及工程热物理—热能工程]