Numerical simulation and mechanism of jet atomization in water-sparged aerocyclone

doi:10.11949/j.issn.0438-1157.20151032

Abstract

Abstract:

Water-sparged aerocyclone (WSA) is a new type of high efficient gas-liquid mass transfer reaction equipment. The gas phase pressure drop characteristics, liquid phase reflux ratio and jet atomization process in the WSA were better simulated using the Reynolds stress model (RSM) and the multiphase flow model of volume of fluid (VOF). The mechanism of jet atomization process in the WSA was also discussed in detail. Both simulation and experiment results illustrated that the gas phase pressure drop of WSA will go through a low pressure drop zone, a pressure drop jump zone, a pressure drop transitional zone and a high pressure drop zone with the increase of gas inlet velocity. The determination method of a turning point between two adjacent pressure drop areas was given. The water jet presents steady jet, deformation and bag-like breakup, bag-like breakup and shear atomization, shear atomization and liquid drop centrifugation, respectively, in the above-mentioned pressure drop areas. The water jet in the WSA was fully atomized and the mass transfer interface between gas and liquid phases was maximized when the gas phase inlet velocity reached the turning point between the pressure drop transitional area and the high pressure drop area. The results could be used as a theoretic basis for establishing a adjusting method for jet atomization and flow field in the WSA.

Key words: water-sparged aerocyclone, jet atomization, numerical simulation, pressure drop characteristics

摘要：

水力喷射空气旋流器(WSA)是一种新型高效的气液传质反应设备。采用雷诺应力模型和VOF两相流模型较好地模拟了WSA的气相压降特性、液相回流比和射流雾化过程,并讨论分析了雾化过程的机理。模拟和实验研究表明,WSA的气相压降随着进口气速的增加先后出现低压降区、压降突跳区、压降过渡区和高压降区4个特征区域,并给出了不同压降区域之间转折点气速的计算方法。射流在这4个压降区域里,分别表现为稳态射流、变形与袋式破碎、袋式破碎与剪切雾化和剪切雾化与离心分离等流态。射流在压降过渡区与高压降区的转折点左右实现充分雾化并达到最大相间传质面积。研究结果为建立基于WSA压降特性的射流雾化与流场调控方法提供了理论依据。

关键词: 水力喷射空气旋流器, 射流雾化, 数值模拟, 压降特性

CLC Number:

TQ028

QIU Facheng, XU Fei, QUAN Xuejun, LUO Dan, DAI Mingxing, WU Jingping. Numerical simulation and mechanism of jet atomization in water-sparged aerocyclone[J]. CIESC Journal, 2016, 67(4): 1269-1276.

邱发成, 徐飞, 全学军, 罗丹, 代明星, 吴京平. 水力喷射空气旋流器中射流雾化过程模拟及其机理[J]. 化工学报, 2016, 67(4): 1269-1276.

References 21

[1]	林宇震, 李林, 张弛, 等. 液体射流喷入横向气流混合特性研究进展[J]. 航空学报, 2014, 35(1): 46-57. DOI:10.7527/S1000-6893. 2013.0346. LIN Y Z, LI L, ZHANG C, et al. Progress on the mixing of liquid jet injected into a crossflow[J]. Acta Aeronautica et Astronautica Sinica, 2014, 35(1): 46-57. DOI:10.7527/S1000-6893.2013.0346.
[2]	安彦召, 黄豪中, 裴毅强, 等.车用柴油机燃油喷雾的研究发展[J]. 小型内燃机与摩托车, 2012, 41(5): 87-92. AN Y Z, HUANG H Z, PEI Y Q, et al. The development of automotive diesel engine fuel spray research[J]. Small Internal Combustion Engine and Motorcycle, 2012, 41(5): 87-92.
[3]	刘静, 徐旭. 高速气流中横向液体射流雾化研究进展[J]. 力学进展, 2009, 39(3): 273-283. LIU J, XU X. The research development of liquid jet atomization in high speed crossflow[J]. Advances in Mechanics, 2009, 39(3): 273-283.
[4]	史绍熙, 林玉静, 杜青, 等. 射流参数对旋流雾化的影响[J]. 燃烧科学与技术, 1999, 5(1): 1-6. SHI S X, LIN Y J, DU Q, et al. Effects of spray parameters on the breakup of a swirling liquid jet[J]. Journal of Combustion Science and Technology, 1999, 5(1): 1-6.
[5]	严春吉, 殷佩海, 解茂昭. 液体射流在旋转气流中的雾化机理研究[J]. 内燃机学报, 2004, 22(5): 425-432. YAN C J, YIN P H, XIE M Z. Mechanisms of atomization of a liquid jet surrounded by swirling airstreams[J]. Transactions of CSICE, 2004, 22(5): 425-432.
[6]	QUAN X J, WANG F P, ZHAO Q H, et al. Air stripping of ammonia in a water-sparged aerocyclone reactor[J]. Journal of Hazardous Materials, 2009, 170(2/3): 983-988.
[7]	程治良, 全学军, 代黎, 等. 水力喷射空气旋流器用于含Cr(Ⅵ)废水处理[J]. 化工学报, 2014, 65(4): 1403-1410. DOI: 10.3969/j.issn. 0438-1157.2014.04.034. CHENG Z L, QUAN X J, DAI L, et al. Treatment of Cr(Ⅵ)-containing wastewater in a water-sparged aerocyclone[J]. CIESC Journal, 2014, 65(4): 1403-1410. DOI: 10.3969/j.issn.0438-1157. 2014.04.034.
[8]	赵清华, 全学军, 程治良, 等. 水力喷射-空气旋流器用于湿法烟气脱硫及其传质机理[J]. 化工学报, 2013, 64(11): 3993-4000. DOI: 10.3969/j.issn.0438-1157.2013.11.015. ZHAO Q H, QUAN X J, CHENG Z L, et al. Wet desulfurization of flue gas and mass transfer mechanism in a water-sparged aerocyclone[J]. CIESC Journal, 2013, 64(11): 3993-4000. DOI: 10.3969/j.issn. 0438-1157. 2013.11.015.
[9]	冯磊, 姚青云. 基于VOF模型的泵站压力管道气液两相流数值模拟[J]. 中国农村水利水电, 2012, 12: 124-126. FENG L, YAO Q Y. Numerical simulation of gas-liquid two-phase flow based on the VOF model in pump station pressure piping[J]. China Rural Water and Hydropower, 2012, 12: 124-126.
[10]	张健, 方杰, 范波芹. VOF方法理论与应用综述[J]. 水利水电科技进展, 2005, 25(2): 67-70. ZHANG J, FANG J, FAN B Q. Advances in research of VOF method[J]. Advances in Science and Technology of Water Resources, 2005, 25(2):67-70.
[11]	冯喜平, 赵胜海, 李进贤, 等. 不同湍流模型对旋涡流动的数值模拟[J]. 航空动力学报, 2011, 26(6): 1209-1214. FENG X P, ZHAO S H, LI J X, et al. Numerical simulation of swirling flow with different turbulent models[J]. Journal of Aerospace Power, 2011, 26(6): 1209-1214.
[12]	WU J P, ZHANG Y H, WANG H L. Numerical study on tangential velocity indicator of free vortex in the cyclone[J]. Separation and Purification Technology, 2014, 132: 541-551.
[13]	SWAIN S, MOHANTY S. A 3-dimensional Eulerian-Eulerian CFD simulation of a hydrocyclone[J]. Applied Mathematical Modelling, 2013, 37(5): 2921-2932.
[14]	KUANG S B, CHU K W, YU A B, et al. Numerical study of liquid-gas-solid flow in classifying hydrocyclones: effect of feed solids concentration[J]. Minerals Engineering, 2012, 31: 17-31.
[15]	HREIZ R, GENTRIC C, MIDOUX N. Numerical investigation of swirling flow in cylindrical cyclones[J]. Chemical Engineering Research and Design, 2011, 89(12): 2521-2539.
[16]	朱辉, 杨志刚. 基于雷诺应力模型的轿车外流场建模与仿真[J]. 计算机辅助工程, 2007, 16(3): 88-91. ZHU H, YANG Z G. Modeling and simulation on outer flow field around sedan based on RSM[J]. Computer Aided Engineering, 2007, 16(3): 88-91.
[17]	CHU K W, WANG B, XU D L, et al. CFD-DEM simulation of the gas-solid flow in a cyclone separator[J]. Chemical Engineering Science, 2011, 66(5): 834-847.
[18]	SALLAM K A, AALBURG C, FAETH G M. Breakup of round nonturbulent liquid jets in gaseous crossflow[J]. AIAA Journal, 2004, 42(12): 2529-2540.
[19]	HERRMANN M. Detailed numerical simulations of the primary atomization of a turbulent liquid jet in crossflow[J]. Journal of Engineering for Gas Turbines & Power, 2009, 132(6): 061506-10.
[20]	MASHAYEK A, ASHGRIZ N. Atomization of a Liquid Jet in A Crossflow[M]//Handbook of Atomization and Sprays. Toronto: Nasser Ashgriz, 2011: 657-683.
[21]	赵清华, 全学军, 程治良, 等. 水力喷射－空气旋流器中气液传质特性及其机理[J]. 化工学报, 2013, 64(10): 3652-3657. DOI: 10.3969/j.issn.0438-1157.2013.10.023. ZHAO Q H, QUAN X J, CHENG Z L, et al. Mass transfer characteristics and mechanism in a water-sparged aerocyclone[J]. CIESC Journal, 2013, 64(10): 3652-3657.DOI: 10.3969/j.issn.0438-1157. 2013.10.023.