脉冲射流-刚柔组合桨强化流体混沌混合及传质性能研究

doi:10.11949/0438-1157.20200303

化工学报 ›› 2020, Vol. 71 ›› Issue (10): 4632-4641.DOI: 10.11949/0438-1157.20200303

脉冲射流-刚柔组合桨强化流体混沌混合及传质性能研究

刘作华^1,³(),孙伟^1,³,熊黠^1,³,陶长元^1,³,王运东²,程芳琴⁴

^1.重庆大学化学化工学院，重庆 400044
^2.清华大学化学工程系，北京 100084
^3.煤矿灾害动力学与控制国家重点实验室，重庆大学，重庆 400044
^4.山西大学资源与环境工程研究所，山西太原 030006

收稿日期:2020-03-23 修回日期:2020-07-10 出版日期:2020-10-05 发布日期:2020-10-05
通讯作者: 刘作华
作者简介:刘作华（1973—），男，博士，教授，liuzuohua@cqu.edu.cn
基金资助:
国家重点研发计划项目(2017YFB0603105);国家自然科学基金项目(21636004);重庆市技术创新与应用示范专项产业类重点研发项目(cstc2018jszx-cyzdX0085)

Chaotic mixing performance and mass transfer enhanced by rigid-flexible impeller with pulse jet

Zuohua LIU^1,³(),Wei SUN^1,³,Xia XIONG^1,³,Changyuan TAO^1,³,Yundong WANG²,Fangqin CHENG⁴

^1.School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China
^2.Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
^3.State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China
^4.Institute of Resources and Environment Engineering, Shanxi University, Taiyuan 030006, Shanxi, China

Received:2020-03-23 Revised:2020-07-10 Online:2020-10-05 Published:2020-10-05
Contact: Zuohua LIU

摘要/Abstract

摘要：

传统搅拌反应器普遍使用刚性桨进行机械搅拌，导致反应器内容易产生混合隔离区而降低流体混合效率。采用多流场耦合诱发混沌现象，促使更多流体进入混沌状态，是提高流体混合效率的有效途径之一。结合Matlab软件编译PJ-RF-RT体系中的压力脉动信号得到最大Lyapunov指数（LLE）与多尺度熵（MSE），探究不同脉冲周期下占空比、桨型、柔性桨叶厚度、桨离底高度及脉冲空气射流量对搅拌反应器内流体混沌混合的影响，同时，对比分析了桨型、射流类型、气流量对体积氧传质系数K_La的影响。研究结果表明，在脉冲周期T=0.4 s，占空比D=80%时，RF-RT桨体系较R-RT桨体系的LLE增大了11.58%，且RF-RT体系的MSE显著高于R-RT桨体系，表明脉冲射流刚柔组合桨体系能更好地诱发流体混沌，增大流体混合效率，均化体系能量分布。此外，脉冲射流耦合RF-RT桨体系增强了流体的湍流特性，促使液膜厚度减小，强化了传质，在单位体积功耗P_v=360 W/m³时，PJ-RF-RT体系的K_La较PJ-R-RT提高了13.46%，PJ-R-RT体系的K_La较SJ-R-RT提高了11.86%。

关键词: 混沌, 脉冲射流, 刚柔组合桨, 最大Lyapunov指数, 传质系数

Abstract:

Conventional stirred reactors generally use rigid impeller for mechanical stirring, which leads to the easy creation of isolation mixing regions in the reactor and reduces the efficiency of fluid mixing. The use of multi-flow field coupling to induce chaos and promote more fluids into a chaotic state is one of the effective ways to improve fluid mixing efficiency. In this work, the largest Lyapunov exponent(LLE) and multi-scale entropy(MSE) are investigated with the Matlab compile pressure pulsation signals. The effects of duty ratio, paddle type, flexible paddle thickness, paddle height from the bottom and pulsed air jet flow rate on the chaotic mixing of fluids in a stirred reactor under different pulse periods are explored. In addition, the effects of different impeller types, jet types and air jet flow rate on the volume oxygen mass transfer coefficient K_La are compared and analyzed. When T=0.4 s and D=80%, the results show that the LLE of the rigid-flexible RT impeller compared with the rigid RT impeller increases 11.58% and the MSE of the rigid-flexible RT impeller is also larger than that of rigid RT impeller. It was showed that the pulsed jet rigid-flexible impeller system can better enhance fluid chaos, increase the fluid mixing efficiency and homogenize the system energy distribution. In addition, pulse jet coupling RF-RT impeller system enhances the turbulent characteristics of the fluid, promotes the reduction of the thickness of the liquid film, strengthens the mass transfer and increases the K_La value of the system. When power consumption per unit volume is 360 W/m³, the K_La of the PJ-RF-RT system compared with the PT-R-RT system increases 13.46%, and the K_La of the PJ-R-RT system compared with the SJ-R-RT system increases 11.86%.

Key words: chaos, pulse jet, rigid-flexible impeller, largest Lyapunov exponent, coefficient of mass transfer

中图分类号:

TQ 028.8

刘作华, 孙伟, 熊黠, 陶长元, 王运东, 程芳琴. 脉冲射流-刚柔组合桨强化流体混沌混合及传质性能研究[J]. 化工学报, 2020, 71(10): 4632-4641.

Zuohua LIU, Wei SUN, Xia XIONG, Changyuan TAO, Yundong WANG, Fangqin CHENG. Chaotic mixing performance and mass transfer enhanced by rigid-flexible impeller with pulse jet[J]. CIESC Journal, 2020, 71(10): 4632-4641.

图/表 14

图1 搅拌实验装置1―frequency conversion motor；2―stirring shaft；3―baffle；4―impeller； 5―ring gas sparger；6―logic controller；7―pressure sensor；8―data acquisition card；9―computer；10―air compressor；11―buffer tank； 12―programmable logic controller；13―electromagnetism control valve；14―turbine meter

Fig.1 Mixing experimental apparatus

图2 射流类型

Fig.2 Jet types

图3 实验用桨叶类型

Fig.3 Impellers used in experiment

图4 脉冲电信号波形

Fig.4 Pulse electric signal waveform

图5 脉冲占空比对LLE的影响

Fig.5 Effect of pulsed duty ratio on LLE

图6 桨叶类型对LLE的影响

Fig.6 Effect of impeller types on LLE

图7 柔性桨叶厚度对LLE的影响

Fig.7 Effect of thickness of flexible part on LLE

图8 搅拌桨离底间距对LLE的影响

Fig.8 Effect of impeller off-bottom clearances on LLE

图9 脉冲空气射流量对LLE的影响

Fig.9 Effect of pulsed air jet flow rates on LLE

图10 桨叶类型对MSE的影响

Fig.10 Effect of impeller types on MSE

图11 柔性桨叶厚度对MSE的影响

Fig.11 Effect of thickness of flexible impeller on MSE

图12 脉冲空气射流量对MSE的影响

Fig.12 Effect of pulsed air jet flow rates on MSE

图13 桨叶类型对KLa的影响

Fig.13 Effect of impeller types on KLa

图14 脉冲气流量对KLa的影响

Fig.14 Effect of pulsed air jet flow rates on KLa

参考文献 29

3	杨锋苓, 周慎杰, 张翠勋, 等. 偏心搅拌槽固液悬浮特性[J]. 过程工程学报, 2008, 8(6): 1064-1069.
	Yang F L, Zhou S J, Zhang C X. et al. Investigation on solid-liquid suspension performance in an eccentrically stirred tank [J]. The Chinese Journal of Process Engineering, 2008, 8(6): 1064-1069.
4	Yao W G, Sato H, Takahashi K, et al. Mixing performance experiments in impeller stirred tanks subjected to unsteady rotational speeds[J]. Chemical Engineering Science, 1998, 53(17): 3031-3040.
5	Kordas M, Story G, Konopacki M, et al. Study of mixing time in a liquid vessel with rotating and reciprocating agitator[J]. Industrial & Engineering Chemistry Research, 2013, 52(38): 13818-13828.
6	Paglianti A, Liu Z H, Montante G, et al. Effect of macroinstabilities in single- and multiple-impeller stirred tanks[J]. Industrial & Engineering Chemistry Research, 2008, 47(14): 4944-4952.
7	Sadhan C, Tjahjadi M, Ottino J M, et al. Chaotic mixing of viscous fluids by periodic changes in geometry: baffled cavity flow[J]. AIChE Journal, 1994, 40(11): 1769-1781.
8	Hwu T Y. Chaotic stirring in a new type of mixer with rotating rigid blades[J]. European Journal of Mechanics-B/Fluids, 2008, 27(3): 239-250.
9	Chien W L, Rising H, Ottino J M. Laminar mixing and chaotic mixing in several cavity flows[J]. Journal of Fluid Mechanics, 1986, 170: 355-377.
10	Hwu T Y. Fluid stirrings in a circular cavity with various driven boundaries[J]. European Journal of Mechanics-B/Fluids, 2006, 25(2): 192-203.
11	Bulnes‐Abundis D, Alvarez M M. The simplest stirred tank for laminar mixing: mixing in a vessel agitated by an off‐centered angled disc[J]. AIChE Journal, 2013, 59(8): 3092-3108.
12	Parekh D E, Kibens V, Glezer A, et al. Innovative jet flow control-mixing enhancement experiments[C]//34th Aerospace Sciences Meeting and Exhibit. Reno, 1996.
13	Freund J B, Moin P. Jet mixing enhancement by high-amplitude fluidic actuation[J]. AIAA Journal, 2000, 38(10): 1863-1870.
14	Kong B, Li T, Eri Q. Large eddy simulation of turbulent jet controlled by two pulsed jets: effect of forcing frequency[J]. Aerospace Science and Technology, 2019, 89: 356-369.
15	Fan J H, Wang Y D, Fei W Y. Large eddy simulations of flow instabilities in a stirred tank generated by a Rushton turbine[J]. Chinese Journal of Chemical Engineering, 2007, 15(2): 200-208.
16	刘作华, 宁伟征, 孙瑞祥, 等. 偏心空气射流双层桨搅拌反应器流场结构的分形特征[J]. 化工学报, 2011, 62(3): 628-635.
1	刘宝庆, 张义堃, 刘景亮, 等. 新型同心双轴搅拌器功率与混合特性的数值模拟[J]. 化工学报, 2013, 64(4): 1135-1144.
	Liu B Q, Zhang Y K, Liu J L, et al. Numerical simulation of power consumption and mixing characteristic in stirred vessel with novel coaxial mixer[J]. CIESC Journal, 2013, 64(4): 1135-1144.
2	胡银玉, 刘喆, 杨基础, 等. 偏心搅拌反应器内的液相混合行为[J]. 化工学报, 2010, 61(10): 2517-2522.
	Hu Y Y, Liu Z, Yang J C, et al. Liquid mixing in eccentric stirred tank [J]. CIESC Journal, 2010, 61(10): 2517-2522.
16	Liu Z H, Ning W Z, Sun R X, et al. Fractal flow structure in eccentric air jet-stirred reactor with double impeller [J]. CIESC Journal, 2011, 62(3): 628-635.
17	王海楠, 朱金波, 费之奎, 等. 射流-搅拌耦合式煤泥浮选装置的能量转化研究[J]. 选煤技术, 2018, 270(5):24-27.
	Wang H N, Zhu J B, Fei Z K, et al. Study on energy conversion mechanism of jet-stirring integrated fine coal flotation device [J]. Coal Preparation Technology, 2018, 270(5): 24-27.
18	刘作华, 许传林, 何木川, 等. 穿流式刚-柔组合搅拌桨强化混合澄清槽内油-水两相混沌混合[J]. 化工学报, 2017, 68(2): 637-642.
	Liu Z H, Xu C L, He M C, et al. Oil-water biphase chaotic mixing enhanced by punched rigid-flexible combination impeller in mixer-settler[J]. CIESC Journal, 2017, 68(2): 637-642.
19	熊黠, 刘作华, 谷德银, 等. 刚柔组合桨强化粉煤灰酸浸搅拌槽内固液混沌混合[J]. 化工学报, 2019, 70(5): 1693-1701.
	Xiong X, Liu Z H, Gu D Y, et al. Chaotic mixing process of fly ash in acid leaching tank intensified by rigid-flexible impeller [J]. CIESC Journal, 2019, 70(5): 1693-1701.
20	邱发成, 刘作华, 刘仁龙, 等. 偏心射流-刚柔组合桨搅拌器内混沌混合行为研究[J]. 化工学报, 2018, 69(2): 618-624.
	Qiu F C, Liu Z H, Liu R L, et al. Chaotic mixing performance in rigid-flexible impeller stirred tank with eccentric air jet [J]. CIESC Journal, 2018, 69(2): 618-624.
21	Garcia-Ochoa F, Gomez E. Bioreactor scale-up and oxygen transfer rate in microbial processes: an overview[J]. Biotechnology Advances, 2009, 27(2): 153-176.
22	Drandev S, Penev K I, Karamanev D. Study of the hydrodynamics and mass transfer in a rectangular air-lift bioreactor[J]. Chemical Engineering Science, 2016, 146(2): 180-188.
23	Aref H, Balachandar S. Chaotic advection in a Stokes flow[J]. Physics of Fluids, 1986, 29(11):3515-3521.
24	刘作华, 王运东, 陶长元. 流体混沌混合及搅拌过程强化方法[M]. 重庆: 重庆大学出版社, 2016: 24-30.
	Liu Z H, Wang Y D, Tao C Y. Method for Strengthening Chaotic Mixing and Stirring of Fluid [M]. Chongqing: Chongqing University Press, 2016: 24-30.
25	Hewakandamby B N. A numerical study of heat transfer performance of oscillatory impinging jets[J]. International Journal of Heat and Mass Transfer, 2009, 52(1/2): 396-406.
26	Amiri T Y, Moghaddas J S, Moghaddas Y. A jet mixing study in two phase gas–liquid systems[J]. Chemical Engineering Research and Design, 2011, 89(3): 352-366.
27	Costa M, Goldberger A L, Peng C K. Multiscale entropy analysis of complex physiologic time series[J]. Physical Review Letters, 2002, 89(6): 1-4.
28	Prasad K Y, Ramanujam T K. Gas holdup and overall volumetric mass transfer coefficient in a modified reversed flow jet loop reactor[J]. The Canadian Journal of Chemical Engineering, 1995, 73(2): 190-195.
29	Jamshidi A M, Sohrabi M, Vahabzadeh F, et al. Studies on the hydrodynamic behavior and mass transfer in a down-flow jet loop reactor with a coaxial draft tube[J]. Journal of Chemical Technology & Biotechnology: International Research in Process, Environmental & Clean Technology, 2001, 76(1): 39-46.

[1]	王凯玥, 马永丽, 李琛, 刘明言. 气液固微型流化床的气液传质系数[J]. 化工学报, 2022, 73(8): 3529-3540.
[2]	许晓东, 马晨波, 孙见君, 张玉言, 於秋萍. 基于最优传质系数的槽型结构参数对液膜机械密封汽化特性影响及优化[J]. 化工学报, 2022, 73(3): 1147-1156.
[3]	刘作华, 周毅林, 熊黠, 陶长元, 王运东. 逆流桨强化搅拌槽内流体混沌混合及流场结构失稳研究[J]. 化工学报, 2022, 73(1): 222-231.
[4]	谢昭明, 陈庚, 刘仁龙, 刘作华, 岑少斗, 陶长元, 郭胜惠. 刚柔组合桨强化软锰矿浸出过程的反应动力学特性[J]. 化工学报, 2021, 72(5): 2586-2595.
[5]	王冠球, 林冠屹, 朱春英, 付涛涛, 马友光. 微通道反应器的一维放大及气液传质特性[J]. 化工学报, 2021, 72(2): 937-944.
[6]	郭达, 祁贵生, 刘有智, 焦纬洲, 闫文超, 高雨松. 错流旋转填料床的质、热同传性能及传热机理研究[J]. 化工学报, 2021, 72(11): 5543-5551.
[7]	徐百平, 刘彪, 刘尧, 谭寿再, 杜遥雪, 刘春太. 不同错列角三角形转子作用下的分布混合数值模拟[J]. 化工学报, 2020, 71(8): 3545-3555.
[8]	刘作华,杨林荣,熊黠,陶长元,王运东,程芳琴. 多层刚柔组合桨诱发流场界面失稳强化非牛顿流体混沌混合行为[J]. 化工学报, 2020, 71(12): 5470-5478.
[9]	刘作华,魏红军,熊黠,陶长元,王运东,程芳琴. 长短叶片复合型刚柔桨强化搅拌槽内流体混沌混合行为[J]. 化工学报, 2020, 71(11): 5080-5089.
[10]	刘作华,魏红军,熊黠,陶长元,王运东,程芳琴. 错位刚柔桨强化搅拌槽内流体混合实验及数值模拟[J]. 化工学报, 2020, 71(10): 4621-4631.
[11]	李钰冰, 杨茉, 陆廷康, 戴正华. 具有质热源的方腔内对流传热传质及其非线性特性[J]. 化工学报, 2019, 70(S2): 130-137.
[12]	张丽, 由钢, 乔霄峰, 许光文, 刘国桢, 刘云义. 氯碱电解槽内压力波动的混沌分析及流型识别[J]. 化工学报, 2019, 70(S1): 35-44.
[13]	谢昭明, 邓容锐, 刘作华, 邓丽, 李千文, 张柱, 殷兆迁, 陶长元. 钠化焙烧转炉钒渣粉体分形生长的演化行为[J]. 化工学报, 2019, 70(5): 1904-1912.
[14]	李兵, 杨义, 刘作华, 陶长元, 谷德银, 许传林, 王运东. 湿法磷酸固-液体系混沌混合与浸出强化行为[J]. 化工学报, 2019, 70(5): 1742-1749.
[15]	熊黠, 刘作华, 谷德银, 邱发成, 王靓, 陶长元, 王运东. 刚柔组合桨强化粉煤灰酸浸搅拌槽内固液混沌混合[J]. 化工学报, 2019, 70(5): 1693-1701.

脉冲射流-刚柔组合桨强化流体混沌混合及传质性能研究

Chaotic mixing performance and mass transfer enhanced by rigid-flexible impeller with pulse jet

RichHTML

PDF (PC)

可视化

摘要/Abstract

引用本文

使用本文

图/表 14

参考文献 29

相关文章 15

编辑推荐

Metrics

本文评价