飞灰回燃对燃烧福建无烟煤CFB锅炉运行影响的研究

利用热天平实验研究了飞灰碳厦其入炉煤的反应性，从理论上分析了飞灰回燃对CFB锅炉燃烧效率的影响，并通过工业试验测试了回燃飞灰量对锅炉返料器运行温度、飞灰的粒度分布及其含碳量、锅炉燃烧效率及其它运行参数的影响。研究表明，燃烧福建无烟煤CFB锅炉飞灰碳的反应性高于其对应入炉煤。回燃飞灰的含碳量、回燃飞灰量与入炉煤量的比值等参数对锅炉燃烧效率有重要影响。采取飞灰回燃技术有利于降低飞灰含碳、降低返料器运行温度和提高锅炉燃烧效率，但当回燃飞灰量较大时会影响锅炉的稳定运行。

An Investigation of the Impact of Fly-ash Reburning on the Operation of an Anthracite-firing CFB (Circulating Fluidized Bed) Boiler

The reactivity of fly-ash carbon and that of other coals fed into a boiler was investigated and compared through experiments with the help of a thermobalance.A theoretical analysis was conducted of the impact of fly-ash reburning on the combustion efficiency of a CFB(circulating fluidized bed) boiler.Moreover,by way of industrial tests investigated and measured was the impact of the fly-ash quantity recycled for reburning on the following items: the operating temperature of a recycle-to-boiler device,fly-ash particle distribution and its carbon content,boiler combustion efficiency and other operating parameters.The results of the investigation indicate that the reactivity of fly-ash carbon of the CFB boiler burning Fujian anthracite is higher than that of other corresponding coals fed into the boiler.In addition,other parameters,such as carbon content of the reburnt fly ash,the ratio of the reburnt fly ash amount to other coals fed into the boiler,have a major influence on the combustion efficiency of the boiler. The use of fly-ash reburning technology will be conducive to reducing the carbon content of the fly ash and the operating temperature of recycle-for reburning device as well as enhancing the combustion efficiency of the boiler.However,a relatively large amount of fly ash assigned for reburning will affect the stable operation of the boiler.