华电技术 ›› 2020, Vol. 42 ›› Issue (7): 1-10.

• 半焦与煤混合燃烧 •    下一篇

粒径对热解半焦和烟煤掺混燃烧特性的影响和试验研究

  

  1. 哈尔滨工业大学 能源科学与工程学院,哈尔滨 150001
  • 出版日期:2020-07-24 发布日期:2020-07-24

Experimental investigation on the influence of particle diameter on co-combustion characteristics of pyrolyzed semi-coke and bituminous coal

  1. School of Energy Science and Engineering,Harbin Institute of Technology,Harbin 150001,China
  • Online:2020-07-24 Published:2020-07-24

摘要: 在350 kW中试规模的煤粉燃烧试验台上研究了燃料粒径对热解半焦和烟煤掺混燃烧的着火、燃烧过程的影响。试验对炉膛中心轴向及主燃区径向上的烟气温度和烟气组分中O2,CO,NO的含量变化进行了测量。结果表明:随着混合燃料粒径的增大,射流火焰着火距离先降低后增加,整体燃烧强度也是先增强后减弱,当R90=20%时着火距离最短,为164 mm,此粒径下对应的整体燃烧强度也最大。着火初期NO的质量浓度随着粒径的增大而减少,主燃区出口处NO的质量浓度则随着粒径的增大先降低后增加,当R90=20%时NO排放量最低,为438 mg/m3。在该试验条件下,综合考虑着火距离、燃烧强度和主燃区 NO 排放量,粒径在 R90=20% 时最有利于热解半焦和烟煤掺混燃烧。

关键词: 半焦, 混合燃烧, 粒径, 着火特性, NOx排放

Abstract: The influence of fuel particle diameter on co-combustion characteristics of pyrolyzed semi-coke and bituminous coal was studied in a 350 kW pilot-scale pulverized coal combustion system.The variation of flue gas temperature and the mass concentrations of O2,CO and NO in the flue gas were measured along the furnace central axis and the primary combustion zone radial direction.According to the testing results,with the increase of blended fuel particle diameter,the jet flame ignition distance decreased first and then increased,while the overall combustion intensity was of an opposite change trend.When R90 is 20%,the ignition distance bottomed out at 164 mm and the overall combustion intensity reached the highest value.At the initial stage of combustion,the mass concentration of NO dropped with the enlarging particle size until it hit the bottom at 438 mg/m3 when the R90 was 20%.In this test,considering the ignition distance,combustion intensity and NO emission from the primary combustion zone comprehensively,it is found that pyrolyzed semi-coke and bituminous coal particle of this size is more conductive to co-combustion.

Key words: semi-coke, co-combustion, particle size, ignition characteristics, NOx emission