引进300MW循环流化床锅炉后燃特性试验研究

Experimental Study on Post Combustion Characteristics of the Imported 300 MW Circulating Fluidized Bed Boiler

利用自制的取样装置对引进300 MW循环流化床(circulating fluidized bed,CFB)锅炉外循环回路的烟气成分进行现场测试,研究了锅炉外循环回路中旋风分离器和外置式换热器的燃烧特性,结果表明:引进300 MW CFB锅炉的外循环回路存在显著的后燃现象,且后燃主要集中在旋风分离器上。分离器出口烟气温升可达135℃,分离器耗氧量占整个锅炉燃烧过程耗氧量的12%左右。外置式换热器内存在燃烧现象,且不同功能的外置式换热器的燃烧特性有着较大差异,用于调节炉温的外置式换热器耗氧量可达用于调节再热汽温的外置式换热器耗氧量的2倍。研究结果可为新锅炉的设计提供参考。

Gas concentrations of the external circulation loop in the imported 300 MW circulating fluidized bed（CFB） boiler were measured by self-made probes to investigate the combustion characteristics of the cyclones and external heat exchangers（EHEs）.Results implied that there was significant post combustion phenomenon in the boiler＇s external circulation loop,and most of the combustion was from the cyclones.The flue gas temperature at the cyclone outlet could be 135 ℃ higher than that at the cyclone inlet.The ratio of the O2 consumption in the cyclone to that of the whole combustion process in the boiler could be as high as 12%.With regard to the EHEs,the inside combustion phenomenon was not as severe as that in the cyclones.Obvious differences of gas concentrations were observed at the outlet between those EHEs with different functions.The O2 consumption of the furnace temperature adjusting EHEs could be twice that of the reheat steam temperature adjusting EHEs.These experimental results can provide information for the design of mew CFB boilers.