掺氢甲烷射流扩散火焰燃烧特性分析  

Analysis of the Combustion Characteristics of CH4/H_(2) Jet Diffusion Fame

作　　者：李洪旭 肖华华[1] LI Hongxu;XIAO Huahua(State Key Laboratory of Fire Science,University of Science and Technology of China,Hefei 230027,China)

机构地区：[1]中国科学技术大学火灾科学国家重点实验室,合肥230027

出　　处：《工程热物理学报》2023年第11期3172-3182,共11页Journal of Engineering Thermophysics

基　　金：国家重点研发计划(No.2021YFB4000902);国家自然科学基金项目(No.52211530436);国家自然科学基金项目(No.51976210)。

摘　　要：采用数值计算与实验相结合的方法研究了掺氢甲烷射流扩散火焰的燃烧特性。结果表明,热量的传递主要是通过热气流对流进行,上游高温气流快速沿轴向流动,径向热量传递较弱;而下游轴向速度降低,热量径向传递增强。喷嘴附近伴流气边界较为稳定,而下游在涡旋作用下出现显著的扰动。射流速度对火焰特性有较大影响,增大射流速度后,火焰高度、辐射强度以及CO、NO、CO_(2)、H_(2)O浓度皆显著增加,且辐射强度峰值向下游移动。掺氢量对火焰特性也有重要影响,随着H_(2)含量增加,燃料向下游传播距离缩短,CO、NO、CO_(2)浓度降低,H_(2)O浓度增加。Numerical simulation and experiment were used to study the characteristics of CH4/H_(2) jet diffusion flames.The results show that heat is mainly transferred by the convection of hot airflow.The upstream hot airflow is rapidly flowed in the axial direction,which is weak in the radial direction.The axial velocity decreases downstream,resulting in enhanced radial heat transfer.The co-flow boundary near the nozzle is relatively stable,while significant disturbances occur downstream at the effect of vortex.The jet velocity has a great influence on the flame characteristics.With the increase of jet velocity,the flame height,the radiation intensity and the concentration of CO,NO,CO_(2) and H_(2)O increase significantly,and the peak of radiation intensity shifts downstream.The hydrogen content also has an important effect on the flame characteristics.With the increase of H_(2) concentration,the distance that the fuel propagates downstream gradually shortens.In addition,the increase of H_(2) concentration leads to a decrease in CO,NO and CO_(2) concentration,and an increase in H_(2)O concentration.

关 键 词：掺氢甲烷 扩散火焰 火焰高度 温度 自由基 

分 类 号：X932[环境科学与工程—安全科学]