Propagation characteristics of hydrogen-air detonation in bifurcated tubes with different angles
-
摘要: 在3种角度分叉管道内开展化学计量比氢气-空气爆轰实验,采用自制的火焰传感器和烟迹法分别获得了爆轰波传播速度和胞格结构,探究了不同角度管道分叉对爆轰传播的影响。结果表明:氢气-空气爆轰在经过分叉三通时受分叉口稀疏波影响导致爆轰波衰减解耦,但随着入射激波与下游管道壁面碰撞,逐渐由规则反射向马赫反射转变,最终完成重起爆过程。其中,直通支管内爆轰衰减主要受支管入口面积的影响,随着分叉角度增大,入口面积减小,爆轰衰减程度和重起爆距离也随之减小;而分叉支管内,爆轰衰减受支管入口面积与入口渐扩程度共同影响,但随着分叉角度的增大,入口面积变为主要影响因素。不同角度分叉管内的实验结果均表明,初始压力升高能显著提高爆轰稳定性,从而削弱分叉几何结构的影响。Abstract: Study on propagation characteristics of detonation in bifurcated tubes is of great significance to the safety protection of gas explosion in pipelines and engineering application. The propagation states of detonation vary with the geometrical structure when passing through the bifurcated tee. Based on the detonation circular test tube, the stoichiometric hydrogen-air mixture gas with 29.5% H2 in the volume fraction under different initial pressures was ignited by a 10-kV double high-voltage electrode to be detonated before entering the 30°, 45° and 90° bifurcation tees, respectively. The propagation characteristics of the detonation in the bifurcated tubes were analyzed based on the propagation velocity and cellular structure evolution characteristics obtained from the feedback signals of flame sensors and smoke-foils records. The results show that the H2/air detonation will decay when it passes through a bifurcated tee which is affected by rarefaction wave, but it is only a local phenomenon. The detonation re-initiation is gradually completed from regular reflection to Mach reflection after collision of incident shock wave and wall. In the straight branch tube, the detonation decay is mainly affected by the inlet area of the collateral branch tube. With the increase of the bifurcation angle, the inlet area decreases, and the detonation decay and re-initiation distance decrease as well. In the collateral branch tube, the detonation decay is affected by both the inlet area of the collateral branch tube and the gradual expansion of the section. When the bifurcated angle exceeds the critical value, the inlet area becomes the main influence factor. In addition, it is proved that increasing the experimental initial pressure of premixed gas can significantly improve the detonation stability and weaken the influence of bifurcation geometry. The mechanism of detonation decay and re-initiation in the bifurcated tubes is clarified by this study, which enriches the study of detonation diffraction and contributes to provide a scientific reference for engineering application and taking proper measures of explosion safety protection of gas pipelines as well.
-
表 1 直通支管和分叉支管平面结构以及爆轰衰减和重起爆特征
Table 1. Plane structures of straight and collateral branch tubes as well as detonation decay and re-initiated characteristics in them
α/(°) 分叉管道平面结构 直通支管 分叉支管 p0/kPa 传播特征 p0/kPa 传播特征 30 <30 kPa vmin=(0.60~0.65)vCJ
L≥16d17~21 kPa vmin≈0.53vCJ
不能重起爆30~40 kPa vmin=(0.66~0.79)vCJ
L≈14d25~30 kPa vmin=(0.54~0.57)vCJ
有重起爆趋势≥40 kPa vmin≥0.79vCJ
L≤8d≥35 kPa vmin>0.53vCJ
L=(11~16)d45 18 kPa vmin=0.74vCJ
L≈10d
速度波动大<55 kPa vmin=(0.52~0.58)vCJ
L≈18d>18 kPa vmin≥0.86vCJ
L≈10d≥55 kPa vmin≥0.65vCJ
L≈10d90 ≥17 kPa vmin≥0.84vCJ
L=(1~2)d≥17 kPa vmin≥0.72vCJ
L=(3~6)d -
[1] 范玮, 李建玲. 爆震组合循环发动机研究导论 [M]. 北京: 科学出版社, 2014: 80–86. [2] 魏雁昕, 李宝星, 翁春生. 分叉管内爆轰波传播特性实验研究 [J]. 航空兵器, 2017(2): 49–54. DOI: 10.19297/j.cnki.41-1228/tj.2017.02.010.WEI Y X, LI B X, WENG C S. Experimental study on propagation characteristics of detonation wave in bifurcated pipe [J]. Aero Weaponry, 2017(2): 49–54. DOI: 10.19297/j.cnki.41-1228/tj.2017.02.010. [3] HOPPER D R, KING P I, HOKE J L, et al. Development of a continuous branching pulsed detonation engine [C]//Proceedings of the 46th AIAA Aerospace Sciences Meeting and Exhibit. Reno, Nevada, USA: AIAA, 2008. DOI: 10.2514/6.2008-112. [4] LIAW H J. Lessons in process safety management learned in the Kaohsiung gas explosion accident in Taiwan [J]. Process Safety Progress, 2016, 35(3): 228–232. DOI: 10.1002/prs.11818. [5] HOU L F, LI Y Z, QIAN X M, et al. Large-scale experimental investigation of the effects of gas explosions in underdrains [J]. Journal of Safety Science and Resilience, 2021, 2(2): 90–99. DOI: 10.1016/j.jnlssr.2021.03.001. [6] GUO C M, WANG C J, XU S L, et al. Cellular pattern evolution in gaseous detonation diffraction in a 90°-branched channel [J]. Combustion and Flame, 2007, 148(3): 89–99. DOI: 10.1016/j.combustflame.2006.11.001. [7] 王昌建, 徐胜利, 朱建士. 气相爆轰波在分叉管中传播现象的数值研究 [J]. 计算物理, 2006, 23(3): 317–324. DOI: 10.3969/j.issn.1001-246X.2006.03.009.WANG C J, XU S L, ZHU J S. Numerical study of gaseous detonation propagation through a bifurcated tube [J]. Chinese Journal of Computational Physics, 2006, 23(3): 317–324. DOI: 10.3969/j.issn.1001-246X.2006.03.009. [8] 王昌建, 徐胜利, 费立森. 气相爆轰波绕射流场显示研究 [J]. 爆炸与冲击, 2006, 26(1): 27–32. DOI: 10.11883/1001-1455(2006)01-0027-06.WANG C J, XU S L, FEI L S. Flow-field visualization for gaseous detonation diffraction experiments [J]. Explosion and Shock Waves, 2006, 26(1): 27–32. DOI: 10.11883/1001-1455(2006)01-0027-06. [9] WANG C J, XU S L, GUO C M. Gaseous detonation propagation in a bifurcated tube [J]. Journal of Fluid Mechanics, 2008, 599: 81–110. DOI: 10.1017/S0022112007009986. [10] HEIDARI A, WEN J. Numerical simulation of detonation failure and re-initiation in bifurcated tubes [J]. International Journal of Hydrogen Energy, 2017, 42(11): 7353–7359. DOI: 10.1016/j.ijhydene.2016.08.174. [11] JIANG C, PAN J F, ZHU Y J, et al. Influence of concentration gradient on detonation re-initiation in a bifurcated channel [J]. Fuel, 2022, 307: 121895. DOI: 10.1016/j.fuel.2021.121895. [12] 卢秦尉, 熊姹, 范玮. 稀释氩气对分叉管内爆震波绕射的影响 [J]. 推进技术, 2014, 35(11): 1566–1576. DOI: 10.13675/j.cnki.tjjs.2014.11.019.LU Q W, XIONG C, FAN W. Effects of argon dilution on detonation diffraction in branch tube [J]. Journal of Propulsion Technology, 2014, 35(11): 1566–1576. DOI: 10.13675/j.cnki.tjjs.2014.11.019. [13] 李生才, 冯长根, 赵同虎. 拐角角度对爆轰波拐角效应的影响 [J]. 爆炸与冲击, 1999, 19(4): 289–294.LI S C, FENG C G, ZHAO T H. The influence of the angle of convex corner on the effect of detonation waves [J]. Explosion and Shock Waves, 1999, 19(4): 289–294. [14] 恽寿榕, 马峰, 康敬. 爆轰波传播拐角效应的近似理论分析 [C]//中国空气动力学学会第十届物理气体动力学专业委员会会议论文集. 福建厦门: 中国空气动力学会, 2001: 3–8. [15] SHORT M, CHIQUETE C, BDZIL J B, et al. Detonation diffraction in a circular arc geometry of the insensitive high explosive PBX 9502 [J]. Combustion and Flame, 2018, 196: 129–143. DOI: 10.1016/j.combustflame.2018.06.002. [16] 赵曦, 孙校书, 刘诚. 弯管角度对爆轰波传播特性的影响 [J]. 海军航空工程学院学报, 2009, 24(5): 591–593,600. DOI: 10.3969/j.issn.1673-1522.2009.05.026.ZHAO X, SUN X S, LIU C. Effects on explosion wave spreading features by the angle of siphon [J]. Journal of Naval Aeronautical Engineering Institute, 2009, 24(5): 591–593,600. DOI: 10.3969/j.issn.1673-1522.2009.05.026. [17] GWAK M C, YOH J J. Effect of multi-bend geometry on deflagration to detonation transition of a hydrocarbon-air mixture in tubes [J]. International Journal of Hydrogen Energy, 2013, 38(26): 11446–11457. DOI: 10.1016/j.ijhydene.2013.06.108. [18] 齐骏, 潘振华, 张彭岗, 等. 弯管内连续旋转爆轰波传播模式实验研究 [J]. 工程热物理学报, 2017, 38(2): 435–439.QI J, PAN Z H, ZHANG P G, et al. Experimental study on the propagation mode of continuous rotating detonation through the bend [J]. Journal of Engineering Thermophysics, 2017, 38(2): 435–439. [19] MCBRIDE B J, GORDON S. Computer program for calculation of complex chemical equilibrium compositions and applications: Ⅱ. users manual and program description: 19960044559 [R]. Washington, USA: NASA, 1996. [20] 杜扬, 李国庆, 吴松林, 等. T型分支管道对油气爆炸强度的影响 [J]. 爆炸与冲击, 2015, 35(5): 729–734. DOI: 10.11883/1001-1455(2015)05-0729-06.DU Y, LI G Q, WU S L, et al. Explosion intensity of gasoline-air mixture in the pipeline containing a T-shaped branch pipe [J]. Explosion and Shock Waves, 2015, 35(5): 729–734. DOI: 10.11883/1001-1455(2015)05-0729-06. [21] LI L, LI J M, NGUYEN V B, et al. A study of detonation re-initiation through multiple reflections in a 90-degree bifurcation channel [J]. Combustion and Flame, 2017, 180: 207–216. DOI: 10.1016/j.combustflame.2017.03.004. [22] 喻健良, 高远, 闫兴清, 等. 初始压力对爆轰波在管道内传播的影响 [J]. 大连理工大学学报, 2014, 54(4): 413–417. DOI: 10.7511/dllgxb201404007.YU J L, GAO Y, YAN X Q, et al. Effect of initial pressure on propagation of detonation wave in round tube [J]. Journal of Dalian University of Technology, 2014, 54(4): 413–417. DOI: 10.7511/dllgxb201404007. -