| Energy and Enviromental Engineering |
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| Investigation of flame characteristics of low NOx swirl burner |
| ZHOU Hao, MA Wei chen, YANG Yu, CHEN Jian zhong |
| State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China |
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Abstract A flame monitoring system and an air extracting system were used to measure eight swirl burners arranged close to a side wall of a 600 MW pulverized coal utility boiler in order to analyze the flame characteristics of swirl burners. The size of flame, temperature distribution and gas compositions along the axis of the burner, flame brightness and temperature along the elevation were analyzed. Results showed that the expansion angle of the burner flame was about 60°. The diameter of the flame increased firstly and then decreased downstream from the burner outlet, and the maximum diameter was about 1.25 m. The flame diameter reached a minimum value about 1.6 m from the burner outlet, where the secondary air became to mix with the primary air. The central region of the flame was occupied by the primary air with coal particles, which were ignited about 1.3 m downstream of the burner outlet. The peripheral high temperature region was the result of the combustion of volatiles brought back by the recirculation region. Both the brightness and temperature of the flame in the furnace firstly increased and then decreased with the increasing of the elevation. The maximum value of the brightness and temperature emerged at the third layer of burners.
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Published: 01 April 2016
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低氮煤粉旋流燃烧器火焰特性的研究
为了研究实际炉膛中旋流燃烧器火焰的特点,采用火焰拍摄系统和抽气测温系统对一台600 MW电站锅炉上的低氮旋流燃烧器的火焰进行详细的测量,分析该低氮旋流燃烧器的火焰形状、轴向的组分和温度分布、火焰亮度及温度随标高的分布规律等.研究结果表明：该旋流燃烧器火焰的扩展角约为60°,火焰的直径从燃烧器喷口到下游呈现先增大后减小的特点,最大直径约为1.25 m,在距离燃烧器喷口约1.6 m处,火焰直径达到一个极小值,这是因为二次风从该位置开始混入一次风.旋流燃烧器火焰的中心区域为带粉的一次风占据,一次风中煤粉在喷入炉膛1.3 m以后开始着火.旋流燃烧器喷口附近的火焰为回流区带回的挥发份与二次风接触后燃烧产生.该燃烧器火焰从内到外依次可以分为一次风区域、回流区、高温火焰区和二次风区.炉膛内燃烧器火焰的亮度和温度随标高的变化特征是先升高后降低,在第三层燃烧器标高处达到最大值.
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