The effects of O2 concentrations on the ignition and MILD combustion of intensely diluted C2H6 in a counterflow jets
The effects of O2 concentrations on the ignition and MILD combustion of intensely diluted C2H6 in a counterflow jets
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DOI：
10.1016/j.energy.2021.120552
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发表时间：
2021-08
期刊：
影响因子：
9
通讯作者：
Huiqiao Jia;Xiang Qian;Jiarui Li;Jinling Yang;C. Zou;Shiying Cao;H. Yao
中科院分区：
文献类型：
--
作者：
Huiqiao Jia;Xiang Qian;Jiarui Li;Jinling Yang;C. Zou;Shiying Cao;H. Yao
本文对非预混体系中强烈稀释的C2 H6在四种O2体积比（10%、21%、30%和40%）下的点火特性进行了详细的研究。开发了C_1-C_2着火温度的IDIM 2.0预测程序，并用我们和Fotache等人的CH_4和C_2H_6着火温度进行了验证。的实验。通过S曲线分析，自由基浓度增长“慢”的出现并不是稀释对C2 H6着火影响的重要指标。在100%C_2H_6的情况下出现缓慢增长区的原因是许多对点火有重要贡献的反应是吸热的。稀释效应的特点主要体现在两个方面：1）在强稀释条件下，氧化途径进一步扩展到CO2; 2）CH 3 →CO→CO2途径的增强。O2浓度对着火温度的影响随燃料稀释而变化。对于7%C_2H_6，不同O_2浓度的着火温度由低到高的顺序为21% < 10%<40%。在本研究的范围内，预热温度，以保持温和的燃烧下21%O2浓度是最低的强烈稀释C2 H6。
A detailed study on the ignition characteristics of C2H6diluted intensively in non-premixed systems at the four O2volume ratio(10%, 21%, 30% and 40%) has be conducted in this paper. IDIM 2.0 for predicting the ignition temperature of C1–C2has been developed, and been verified by the ignition temperatures of CH4and C2H6from our and Fotache et al.‘s experiments. Through the S-curves analysis, the appearance of the “slow” radical concentration growth is not the important indicator of the effect of dilution on the ignition of C2H6. The reason for the emergence of slow growth zone in the case of 100% C2H6is that many reactions making important positive contribution to the ignition are endothermic. The characteristics of dilution effects are mainly reflected in two aspects: 1)the oxidation pathway is extended further to CO2under intense dilution conditions; 2)the enhancement of the pathway, CH3→CO→CO2. The effect of O2concentration on the ignition temperature will change as the fuel is diluted. For 7% C2H6, the order of ignition temperatures of various O2concentrations from low to high is 21% < 10%<40%. Within the scope of this study, the preheating temperature to maintain MILD combustion under 21% O2concentration is the lowest for intensely diluted C2H6.