【摘要】 针对某电厂600 MW对冲燃烧锅炉高温腐蚀问题，提出一套侧墙贴壁风改造方案。对锅炉改造前后的速度场、温度场和组分分布进行数值模拟，并开展了侧墙近壁面还原性气氛试验和锅炉热效率测试。结果表明：改造后炉内高速区减小，煤粉停留时间变长有利于煤粉充分燃烧，从而降低侧墙近壁面还原性气体浓度；改造后侧墙燃尽风标高上方温度下降，侧墙近壁面烟温偏差减小；侧墙近壁面O₂平均体积分数由0.19%升至2.00%,CO平均体积分数由920×10^-4降至150×10^-4,H₂S平均体积分数由200×10^-6降至150×10^-6,还原性气氛破坏有效缓解了侧墙水冷壁的高温腐蚀。改造后300、450和600 MW负荷下锅炉热效率较改造前分别升高了0.69%、0.71%和0.77%。更多还原

【Abstract】 Aimed at high-temperature corrosion in a 600 MW opposed firing boiler, a sidewall near-wall air protection scheme was proposed. The numerical simulation of the boiler was conducted to analyze the velocity field, temperature field, and component distribution before and after the retrofit under full load condition. After the scheme was implemented in the boiler, the test of reductive atmosphere near the side water wall and thermal efficiency of the boiler was carried out. The implementation of the scheme results in a reduction in the high-speed zone and an increase in the residence time of coal particle, promoting more efficient coal combustion and reducing the concentration of reductive gas near the side wall. The temperature above the over-fire air near the side wall decreases, minimizing the temperature deviation of flue gas. The average volume fraction of O₂ near wall increases 2.00% from 0.19%. The average volume fraction of CO decreases from 920×10^-4 to 150×10^-4,and the average volume fraction of H₂S decreases from 200×10^-6 to 150×10^-6. The reductive atmosphere is effectively destroyed which can effectively alleviate high temperature corrosion. Furthermore, the retrofit led to improvements in thermal efficiency, with increase of 0.69%,0.71%,and 0.77% observed at load levels of 300,450,and 600 MW,respectively. This research aims to provide both theoretical and engineering references for future studies.更多还原