Experimental evaluation of the performance of a flameless combustor
Experimental evaluation of the performance of a flameless combustor
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DOI：
10.1016/j.applthermaleng.2012.07.027
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发表时间：
2013-01
影响因子：
6.4
通讯作者：
A. Rebola;Mário Costa;P. Coelho
中科院分区：
文献类型：
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作者：
A. Rebola;Mário Costa;P. Coelho
本研究的目的是实验研究无焰氧化现象。实验已在一个小规模的燃烧室与甲烷燃烧，并包括详细的测量局部平均温度和浓度的主要气体物种的四个代表性的燃烧室的操作条件，和烟道气测量27个操作条件，以量化的燃烧室性能的过剩空气系数，进气速度，燃料热输入和预热温度的燃烧空气的函数。结果表明，对于本燃烧室，有可能在很宽的操作条件范围内建立无焰条件。详细的燃烧室内数据表明，温度和O2摩尔分数场相对均匀，并且整个燃烧室达到的最大平均温度相对适中，低于1500 °C，即使在燃烧空气预热水平相对较高的条件下。烟道气数据表明，NOx排放量总是很低，无论燃烧室的操作条件。然而，CO和HC排放以及燃烧效率受到过量空气水平和燃烧空气预热的强烈影响。发现燃烧效率与参数（Tair/Tfuel）×（mstecfuel/mstecair）有相当好的相关性，如果其值低于0.1，则与其线性变化，否则保持约等于100%。
The aim of this study was to investigate experimentally the flameless oxidation phenomena. Experiments have been performed in a small-scale combustor fired with methane, and include detailed measurements of local mean temperatures and concentrations of major gas species for four representative combustor operating conditions, and flue-gas measurements for 27 operating conditions to quantify the combustor performance as a function of the excess air coefficient, inlet air velocity, fuel thermal input and preheat temperature of the combustion air. It was demonstrated that for the present combustor it is possible to establish flameless conditions over a wide range of operating conditions. The detailed in-combustor data show that the temperature and the O2mole fraction fields are relatively uniform, and that the maximum mean temperatures reached throughout the combustion chamber are relatively moderate, below 1500 °C, even under conditions in which the level of preheating of the combustion air is relatively high. The flue-gas data reveal that NOxemissions are always very low regardless of the combustor operating conditions. However, the CO and HC emissions, and thus the combustion efficiency, are strongly affected by the levels of excess air and preheating of the combustion air. It was found that the combustion efficiency correlates reasonably well with the parameter (Tair/Tfuel)×(m˙fuel/m˙air), varying linearly with it if its value is below ≈0.1 and remaining equal to approximately 100% otherwise.