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针对低热值煤层气部分预混式旋流燃烧器,通过加装钝体对其结构进行了优化研究,采用数值分析的方法考察了钝体对燃烧器出口速度、温度及甲烷浓度分布等的影响规律。研究表明:在燃气管外壁上加装钝体可以提高燃烧器的部分预混效果,缩短火焰长度;在支撑管出口加装钝体可以提高燃烧器出口气流的射流刚性,使炉内温度分布趋于均匀,同时提高回流区卷吸高温烟气的能力和范围,在喷口出口形成稳定的高温区。通过加装两部分钝体的方法,对燃烧器进行局部优化改进后,燃烧器在保证射流刚性的同时达到良好的燃烧稳定性;燃烧器出口轴向速度梯度和温度随出口钝体锥度的增大而提高,出口钝体锥度应选择34.21°为宜。
In order to optimize the structure of some pre-mixed swirl burners with low calorific value, a bluff body was used to optimize the structure of the combustor. The influence of the bluff body on the exit velocity, temperature and methane concentration distribution was investigated by numerical analysis law. The results show that adding a bluff body to the outer wall of the gas pipe can improve the partial premixing effect of the burner and shorten the length of the flame. Adding a bluff body at the outlet of the support pipe can improve the rigidity of the jet at the outlet of the burner, At the same time, the ability and scope of the high-temperature flue gas to be entrained in the recirculation zone are improved, and a stable high-temperature zone is formed at the exit of the spout. Through the installation of two parts of blunt bodies, the burner is optimized locally, the combustor achieves good combustion stability while ensuring the rigidity of the jet. The axial velocity gradient and temperature at the exit of the combustor increase with the taper of the outlet blunt body Big and improve the export of blunt body taper should choose 34.21 ° is appropriate.