现役热电联产锅炉宽煤种适应性研究

Study on adaptability of wide coal types of an existing cogeneration boiler

围绕一台240 t/h四角切圆的热电联产锅炉,开展宽煤种适应性研究。通过分析该无烟煤锅炉运行现状,提出了开缝钝体燃烧器改造方案;对拟改烧烟煤进行煤质特性试验分析,提出了改烧烟煤的锅炉参数调整策略,分析了对锅炉辅机及系统的影响;基于煤质分析和参数调整,利用FLUENT 16.0软件模拟了不同煤种的炉内燃烧过程。模拟结果表明:改烧烟煤后炉内燃烧状况良好,燃烧火焰中心位置略有抬高,炉膛出口烟气温度与设计煤种工况基本一致;炉膛中心CO体积分数有一定的增加,燃烧器区域四周炉壁附近O2体积分数相对较高;锅炉出口烟气速度略有减小,烟气密度无明显变化。研究工作为中、小型热电联产锅炉宽煤种与宽负荷调节提供了一种有效的方法。

A study on adaptability of wide coal types was carried out around a 240 t/h tangentially fired cogeneration boiler.By analyzing the current operational status of the boiler conventionally designed for anthracite,the burner reforming scheme was proposed.The coal quality characteristics of the proposed bituminous coals were analyzed experimentally.The boiler parameter adjustment strategy of the modified bituminous coals was proposed,and the influence on the auxiliary machine and boiler system was also analyzed.On the basis of coal quality analysis and parameter adjustment,Fluent 16.0 software was applied to simulate the combustion process of different coals in the furnace.The results show that,after the conversion of anthracite to bituminous coal,the combustion in the furnace is in good condition,the center position of the combustion flame slightly elevates,and the flue gas temperature at the exit of the furnace is basically the same as that of the designed coal type.When the bituminous coal is burned,the CO concentration in the center of the furnace obviously increases,and the O2 concentration in the furnace wall area is relatively higher than that of the designed coal type.The flue gas velocity at the boiler exit slightly reduces,and the flue gas density does not change significantly.The research provides an effective method for wide coal type and wide load regulation of small and medium scale cogeneration boilers.