微通道内环状流薄液膜厚度及波动实验研究

doi:10.11949/0438-1157.20240559

摘要/Abstract

摘要：

微通道中环状流广泛应用于精细化学品合成等领域，而环状流中薄液膜的流动形态及厚度对反应过程的热质传递影响显著，因此实验利用激光诱导荧光法对薄液膜厚度进行精准在线测量。结果表明，随气相剪切力增大，液膜厚度降低，波动形态由低频高振幅波转变为高频低振幅波。二氯甲烷为3 ml/min、含气率为0.7时波动频率最高可达260 Hz。在相同含气率下，液膜形态由流体黏度和表面张力决定，液膜厚度随流体黏度增大而增大，液膜波动频率随表面张力增大而减小。通过薄液膜在微通道内受力分析，构建了不同流体的薄液膜厚度的预测模型，预测值与实验值偏差±15%。本研究明晰了微通道内不同物性液体及气速对液膜波动及厚度的影响，为薄液膜强化热质传递提供理论指导。

关键词: 微流体学, 两相流, 薄液膜波动, Micro-LIF, 含气率

Abstract:

Annular flow in microchannels is widely used in the fields of chip heat dissipation and fine chemical synthesis due to its efficient thermal mass transfer. The on-line measurement of the thin liquid film thickness and flow pattern of annular flow was realized by using the Micro-LIF method with an accuracy of ±2 μm. The results show that the liquid film thickness decreases with the increase of gas content (x), and the fluctuation pattern changes from a low-frequency high amplitude wave to a high-frequency low-amplitude wave. the fluctuation frequency of methylene chloride at x = 0.7 and Q_L= 3 ml/min can reach up to 260 Hz. Under the same x, the liquid film morphology is determined by the viscosity and surface tension of liquids, the liquid film thickness increases with the fluid viscosity, and the frequency of liquid film fluctuation decreases with the liquid film surface tension. The prediction model of thin liquid film thickness for different fluids was constructed through the force analysis of thin liquid film, and the maximum deviation of the predicted value from the experimental value was ±30%. This study clarifies the effects of different fluids and gas velocities on the fluctuations and scales of the liquid film in the microchannel, and provides theoretical guidance for the enhanced heat and mass transfer of the thin liquid film.

Key words: microfluidics, two-phase flow, thin liquid film fluctuations, Micro-LIF, gas holdup

中图分类号:

TQ021.1

阮达, 侯静静, 薄紫一, 张帅帅, 马学虎. 微通道内环状流薄液膜厚度及波动实验研究[J]. 化工学报, DOI: 10.11949/0438-1157.20240559.

Da RUAN, Jingjing HOU, Ziyi Bo, Shuaishuai Zhang, Xuehu MA. Study of thin liquid film thickness and fluctuation pattern of annular flow in microchannel[J]. CIESC Journal, DOI: 10.11949/0438-1157.20240559.

图/表 12

图1 微通道内薄液膜实验系统

Fig. 1 Experimental system for thin liquid film in microchannel

图2 不同激光强度下薄液膜拍摄实时画面（QEtOH=3 ml/min，x=0.4）

Fig. 2 Images of thin liquid film taken at different laser intensities （QEtOH=3 ml/min，x=0.4）

表1 不同工况下的实验激光强度

Table 1 Experimental laser intensities under different operating conditions

含气率（x）	激光强度（%）
含气率（x）	水（Water）	乙醇（EtOH）	二氯甲烷（DCM）
0.1	35	35	36
0.2	35	35	38
0.3	38	37	40
0.4 0.5 0.6 0.7	38 40 41 41	38 40 40 42	39 41 43 44

表2 测试流体物性

Table 2 Experimental fluid properties

名称	ρ / kg/m³	μ / μPa s	σ / mN/m
EtOH	785	1077	22.09
DCM	1326	413	28.16
水	997	912	72.18
N₂	1.165	17.48	--

图3 不同流体（水，EtOH，DCM）随含气率（x）变化的液膜可视化图像

Fig. 3 Liquid film visualization images of different fluids （Water，EtOH，DCM） as a function of gas content （x）

图4 不同流量的二氯甲烷随含气率（x）增大的液膜可视化图像

Fig. 4 Liquid film visualization image of dichloromethane with gas content （x） for different flow rates

图5 通道顶部及底部的液膜厚度随时间的变化（QEtOH = 2 ml/min）

Fig. 5 Liquid film thickness at the top and bottom of the channel as a function of time （QEtOH = 2 ml/min）

图6 通道顶部及底部的液膜厚度平均值随x的变化（QEtOH= 2 ml/min）

Fig. 6 Mean value of liquid film thickness at the top and bottom of the channel as a function of x （QEtOH = 2 ml/min）

图7 不同流体（水，EtOH，DCM）液膜厚度平均值随x的变化

Fig. 7 Variation of mean value of liquid film thickness with x for different fluids （Water，EtOH，DCM）

图8 不同流体（水，EtOH，DCM）液膜厚度随时间的变化

Fig. 8 Liquid film thickness with time for different fluids （Water，EtOH，DCM）

图9 不同流体（水，EtOH，DCM）的液膜波动平均振幅及频率随x的变化注:(Water,EtOH,DCM) as a function of x

Fig. 9 Average amplitude and frequency of liquid film fluctuations of different fluids

图10 液膜厚度预测模型的预测值与实验值偏差比较

Fig. 10 Comparison of predicted and experimental deviations of liquid film thickness prediction models

参考文献 31

1	Dong G H, Chen B, Liu B, et al. Advanced oxidation processes in microreactors for water and wastewater treatment: Development, challenges, and opportunities[J]. Water Research, 2022, 211: 118047.
2	Feng H, Zhang Y, Liu J, et al. Towards heterogeneous catalysis: a review on recent advances of depositing nanocatalysts in continuous-flow microreactors[J]. Molecules, 2022, 27(22): 8052.
3	Battat S, Weitz D A, Whitesides G M. An outlook on microfluidics: the promise and the challenge[J]. Lab on a Chip, 2022, 22(3): 530-536.
4	Yan Z F, Tian J X, Du C C, et al. Reaction kinetics determination based on microfluidic technology[J]. Chinese Journal of Chemical Engineering, 2022, 41: 49-72.
5	Ran J F, Wang X X, Liu Y H, et al. Microreactor-based micro/nanomaterials: fabrication, advances, and outlook[J]. Materials Horizons, 2023, 10(7): 2343-2372.
6	张经纬, 周弋惟, 陈卓, 等. 微反应器内的有机合成前沿进展[J]. 化工学报, 2022, 73(8): 3472-3482.
	Zhang J W, Zhou Y W, Chen Z, et al. Advances in frontiers of organic synthesis in microreactor[J]. CIESC Journal, 2022, 73(8): 3472-3482.
7	Firuzi S, Sadeghi R. Simulation of carbon dioxide absorption process by aqueous monoethanolamine in a microchannel in annular flow pattern[J]. Microfluidics and Nanofluidics, 2018, 22(10): 109.
8	Ye X, Cheng Y Q, Chen Y S, et al. Microcavity-enabled local oscillation of Taylor bubbles in a microchannel[J]. Industrial & Engineering Chemistry Research, 2021, 60(2): 1055-1066.
9	尧超群, 乐军, 赵玉潮, 等. 微通道内气-液弹状流动及传质特性研究进展[J]. 化工学报, 2015, 66(8): 2759-2766.
	Yao C Q, YUE Jun, Zhao Y C, et al. Review on flow and mass transfer characteristics of gas-liquid slug flow in microchannels[J]. CIESC Journal, 2015, 66(8): 2759-2766.
10	Cheng L X, Xia G D. Flow patterns and flow pattern maps for adiabatic and diabatic gas liquid two phase flow in microchannels: fundamentals, mechanisms and applications[J]. Experimental Thermal and Fluid Science, 2023, 148: 110988.
11	Shao N, Gavriilidis A, Angeli P. Flow regimes for adiabatic gas–liquid flow in microchannels[J]. Chemical Engineering Science, 2009, 64(11): 2749-2761.
12	Sattari-Najafabadi M, Nasr Esfahany M, Wu Z, et al. Mass transfer between phases in microchannels: a review[J]. Chemical Engineering and Processing - Process Intensification, 2018, 127: 213-237.
13	Jose N A, Zeng H C, Lapkin A A. Hydrodynamic assembly of two-dimensional layered double hydroxide nanostructures[J]. Nature Communications, 2018, 9(1): 4913.
14	Sobieszuk P, Napieralska K. Investigations of mass transfer in annular gas-liquid flow in a microreactor[J]. Chemical and Process Engineering, 2016, 37(1): 55-64.
15	Jose N A, Zeng H C, Lapkin A A. Scalable and precise synthesis of two-dimensional metal organic framework nanosheets in a high shear annular microreactor[J]. Chemical Engineering Journal, 2020, 388: 124133.
16	Etminan A, Muzychka Y S, Pope K. Liquid film thickness of two-phase slug flows in capillary microchannels: a review paper[J]. The Canadian Journal of Chemical Engineering, 2022, 100(2): 325-348.
17	Patel R S, Weibel J A, Garimella S V. Characterization of liquid film thickness in slug-regime microchannel flows[J]. International Journal of Heat and Mass Transfer, 2017, 115: 1137-1143.
18	Donniacuo A, Charnay R, Mastrullo R, et al. Film thickness measurements for annular flow in minichannels: Description of the optical technique and experimental results[J]. Experimental Thermal and Fluid Science, 2015, 69: 73-85.
19	张鹏, 姜玉雁, 王涛. 方管两相流中微液膜的测量与分析[J]. 工程热物理学报, 2022, 43(7): 1911-1915.
	Zhang P, Jiang Y Y, Wang T. Measurement and analysis of square microchannel liquid film in two-phase flow[J]. Journal of Engineering Thermophysics, 2022, 43(7): 1911-1915.
20	Sun Y H, Guo C H, Jiang Y Y, et al. Transient film thickness and microscale heat transfer during flow boiling in microchannels[J]. International Journal of Heat and Mass Transfer, 2018, 116: 458-470.
21	Anastasiou A D, Makatsoris C, Gavriilidis A, et al. Application of μ-PIV for investigating liquid film characteristics in an open inclined microchannel[J]. Experimental Thermal and Fluid Science, 2013, 44: 90-99.
22	Mishra D K, Mohanty D, Gupta R, et al. Effect of bend on film thickness in slug, slug-annular, and annular flow regimes in gas–liquid flow in a microchannel[J]. Industrial & Engineering Chemistry Research, 2022, 61(37): 14081-14092.
23	Bartkus G V, Kuznetsov V V. Experimental study of wavy-annular flow in a rectangular microchannel using LIF method[J]. Journal of Physics: Conference Series, 2021, 2119(1): 012061.
24	Yoshinaga Y., Dang C., Hihara E.Experimental study on two-phase flow pattern and liquid film thickness in microchannels[C]// 15th International Refrigeration and Air Conditioning Conference at Purdue. America: School of mechanical engineering, 2014: 2594.
25	Han Y, Kanno H, Ahn Y J, et al. Measurement of liquid film thickness in micro tube annular flow[J]. International Journal of Multiphase Flow, 2015, 73: 264-274.
26	Patel R S, Garimella S V. Technique for quantitative mapping of three-dimensional liquid–gas phase boundaries in microchannel flows[J]. International Journal of Multiphase Flow, 2014, 62: 45-51.
27	Zhao Z Y, Wang B H, Wang J, et al. Liquid film characteristics measurement based on NIR in gas–liquid vertical annular upward flow[J]. Measurement Science and Technology, 2022, 33(6): 065014.
28	Xu Z, Jiang Y D, Wang B L, et al. Void fraction measurement of gas–liquid two-phase flow with a 12-electrode contactless resistivity array sensor under different excitation patterns[J]. Measurement Science and Technology, 2020, 31(11): 115103.
29	Zhang P, Wang T, Jiang Y Y, et al. Experimental study of initial liquid film thickness in square microchannel two-phase flow[J]. Heat Transfer Research, 2022, 53(10): 51-69.
30	Wang M, Bai Y X, Liu J G, et al. Experimental and modeling study on liquid film thickness of horizontal gas-liquid annular flow using ultrasonic method[J]. Flow Measurement and Instrumentation, 2024, 96: 102538.
31	Shri Vignesh K, Vasudevan C, Arunkumar S, et al. Laser induced fluorescence measurement of liquid film thickness and variation in Taylor flow[J]. European Journal of Mechanics - B, 2018, 70: 85-92.

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