Flame patterns of gasoline-air mixture deflagration in a confined space
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摘要: 通过受限空间油气爆燃可视化实验发现,在不同初始油气体积分数下,爆燃火焰呈现出不同的表观特征,据此提出了受限空间油气爆燃的3种火焰形态,即光滑球形火焰、褶皱球形火焰和卷曲絮状火焰。分析了3种火焰形态的形成机理,并通过实验观测与理论分析,给出了区分3种火焰形态的临界条件。结合实验中采集到的关键参数,总结了不同的火焰形态下受限空间油气爆燃的反应产物、最大压力、升压速率、反应时间、火焰强度等关键参数的特征与变化规律。Abstract: In order to investigate the flame characteristics of gasoline-air mixture deflagration in a confined space, visualized experiments were performed at different equivalence ratios. Three flame patterns of gasoline-air deflagration were proposed: smooth spherical flame, fold spherical flame and curling flocculent flame. Based on the chemical kinetics and flame spectroscopy, the forming mechanism of each flame pattern was examined. Then, the critical equivalence ratio, here used to distinguish the flame patterns, was obtained by theoretical analysis and experimental measurement. Combined with the collected key parameters in the experiments, the differences in key parameters of each flame pattern were summarized, such as reaction products, rate of pressure rise, flame intensity, duration of flame and maximum pressure.
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Key words:
- mechanics of explosion /
- flame pattern /
- deflagration /
- gasoline-air mixture /
- confined space
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表 1 3种典型火焰形态下的油气爆燃特征变化规律
Table 1. Gasoline-air mixture deflagration characteristicsof three different flame patterns
爆燃参数 光滑球形火焰 褶皱球形火焰 卷曲絮状火焰 φ < 1 1~1.47 >1.47 YCO 增加 增加 最大 YCO2 增加后减小 减小 最小 YO2 减小 增加后减小 最小 I 增加 减小 增加 ṗ 增加 最大 减小 τ 减小 最小 增加 pm 增加 最大 减小 注:增加或减小均指随初始油气体积分数增加而发生的变化。 -
[1] Kuo K K. Principles of combustion[M]. John Wiley & Sons, 2005. [2] Turns S R. An introduction to combustion: Concepts and applications[M]. McGrw-Hill Companies, 2000. [3] 杜扬.油料火灾科学导论[M].北京:中国石化出版社, 2010. [4] Yoshida A, Tsuji H. Characteristic scale of wrinkles in turbulent premixed flames[C]//Symposium (International) on Combustion. Elsevier, 1982: 403-411. [5] Oh K H, Kim H, Kim J B, et al. A study on the obstacle-induced variation of the gas explosion characteristics[J]. Journal of Loss Prevention in the Process Industries, 2001, 14(6):597-602. doi: 10.1016/S0950-4230(01)00054-7 [6] Zhang P, Du Y, Zhou Y, et al. Explosions of gasoline-air mixture in the tunnels containing branch configuration[J]. Journal of Loss Prevention in the Process Industries, 2013, 26(6):1279-1284. doi: 10.1016/j.jlp.2013.07.003 [7] Zhang M, Wang J, Wu J, et al. Flame front structure of turbulent premixed flames of syngas oxyfuel mixtures[J]. International Journal of Hydrogen Energy, 2014, 39(10):5176-5185. doi: 10.1016/j.ijhydene.2014.01.038 [8] Jerzembeck S, Peters N, Pepiot-Desjardins P, et al. Laminar burning velocities at high pressure for primary reference fuels and gasoline: Experimental and numerical investigation[J]. Combustion and Flame, 2009, 156(2):292-301. doi: 10.1016/j.combustflame.2008.11.009 [9] Kim W K, Mogi T, Dobashi R. Effect of propagation behaviour of expanding spherical flames on the blast wave generated during unconfined gas explosions[J]. Fuel, 2014, 128(14):396-403. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=3976c50ca8d212461034cd90c3dcd31b [10] Tang C, Zhang S, Si Z, et al. High methane natural gas/air explosion characteristics in confined vessel[J]. Journal of Hazardous Materials, 2014, 278:520-528. doi: 10.1016/j.jhazmat.2014.06.047