Effects of H2O and CO2 diluted oxidizer on the structure and shape of laminar coflow syngas diffusion flames
Effects of H2O and CO2 diluted oxidizer on the structure and shape of laminar coflow syngas diffusion flames
复制标题
H2O和CO2稀释氧化剂对层流共流合成气扩散火焰结构和形状的影响
DOI：
10.1016/j.combustflame.2016.12.001
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发表时间：
2017-03-01
影响因子：
4.4
通讯作者：
Tang, Wenbo
中科院分区：
文献类型：
--
作者：
Xu, Huanhuan;Liu, Fengshan;Tang, Wenbo
通过实验和数值模拟研究了H2O和CO2置换空气中N2-对同向层流合成气（CO-H-2）扩散火焰结构和形状的影响。使用B型热电偶测量沿火焰中心线的沿着温度。分别用增强型CCD摄像机和CCD摄像机捕捉OH*-化学发光和火焰亮度，测定火焰高度和半径。合成气扩散火焰的数值模拟使用详细的热和传输特性和化学反应机制的戴维斯等人。（2005年）。在额外的数值计算中引入了四对人工物种，以隔离H2O和CO2的化学、热、传输和辐射效应。实验和数值计算结果表明，H2O和CO2替代氧化剂中的N2-均降低了火焰的峰值温度，但对火焰中心线温度分布的影响不同。添加H2O和CO2的热效应和辐射效应都降低了火焰温度。CO2和H2O的化学和传输效应对火焰温度的影响不同。H2O的加入通过H+O-2 =O+OH和O+H2O= 2 OH促进了OH的生成，而CO2的加入通过抑制上述反应降低了OH的生成。添加H2O时，OH浓度越高，燃烧强度越高，火焰高度和半径越小。相比之下，CO2的添加抑制火焰温度和整个燃烧过程，导致火焰高度和半径增加。(C)2016由Elsevier Inc.出版代表燃烧研究所
The effects of up to 30% H2O and CO2 replacement of N-2 in air on the structure and shape of laminar coflow syngas (CO-H-2) diffusion flames were experimentally and numerically studied. Temperatures along the flame centerline were measured using a type-B thermocouple. The OH*-chemiluminescence and flame luminance were captured respectively by an intensified CCD camera and a CCD camera to determine the flame height and radii. The syngas diffusion flames were numerically modeled using detailed thermal and transport properties and the chemical reaction mechanism of Davis et al. (2005). Four pairs of artificial species were introduced in additional numerical calculations to isolate the chemical, thermal, transport, and radiative effects of H2O and CO2. The experimental and numerical results show that H2O and CO2 replacement of N-2 in the oxidizer reduce the peak flame temperature, but they influence the flame centerline temperature distributions differently. The thermal and radiative effects of both H2O and CO2 addition decrease the flame temperatures. The chemical and transport effects of CO2 and H2O affect flame temperatures differently. H2O addition promotes the OH concentration though H+O-2 =O+OH and O+H2O=2OH, while CO2 addition decreases the OH concentration by suppressing those reactions. The higher concentrations of OH under H2O addition signify higher combustion intensity and hence lead to decreased flame height and radius. In contrast, the addition of CO2 suppresses flame temperature and the overall combustion process, resulting in increased flame height and radius. (C) 2016 Published by Elsevier Inc. on behalf of The Combustion Institute.