Analysis of turbulent heat transfer characteristics of nanofluids in the Lightnin static mixer

doi:10.16085/j.issn.1000-6613.2021-0928

Abstract

Abstract:

The static mixer is a kind of highly efficient and online heat and mass transfer enhanced equipment and has excellent characteristics in the chemical process intensification. The lack of research about the effects of physical properties of nanofluids on the heat transfer characteristics in the Lightnin static mixer (LSM) restricts a further industrial application of LSM in the field of enhancing heat transfer. The effects of volume fraction, particle type and size of nanoparticles on the heat transfer in LSM were numerically evaluated under the conditions of Re=8000—28000 and constant heat flux using the SST k-ω turbulence model and multiphase mixture model. With the increasing of volume fraction of Cu-H₂O nanofluids, the comprehensive heat transfer performance (PEC) and synergy between velocity field and temperature field of nanofluids are gradually enhanced while the total entropy production rate and Be gradually decrease. The PEC values of Cu-H₂O nanofluids with volume fractions from 0.5% to 2.0% could be obtained up to 2.16—2.25, 3.16—3.25, 3.94—4.15 and 4.64—5.16 at Re=8000—28000, respectively. The enhanced heat transfer performance of Cu-H₂O nanofluids is much better than that in the Al₂O₃-H₂O and CuO-H₂O nanofluids. The average PEC of Al₂O₃-H₂O and CuO-H₂O are 0.47 and 0.46 times of Cu-H₂O nanofluids, respectively. With the increasing particle size of Cu-H₂O nanofluid, the comprehensive heat transfer performance and synergistic performance of the nanofluids are gradually weakened while the total entropy production rate and Be gradually increase.

Key words: static mixer, nanofluid, total entropy generation, field synergy number, heat transfer, numerical simulation

摘要：

静态混合器作为一种高效传热传质连续流强化设备，在化工过程强化技术中具有明显技术特色。由于缺乏纳米流体的物性对Lightnin静态混合器（LSM）内传热特性影响的研究，一定程度上制约了LSM强化传热应用的进一步推广。本文采用混合多相流模型和SST k-ω湍流模型，在Re=8000~28000和恒热流密度条件下，从熵产以及速度场与温度场的协同性等方面分析纳米颗粒的体积分数、种类及粒径大小对LSM内传热特性的影响。结果表明，随着Cu纳米颗粒体积分数的增加，纳米流体的综合传热性能及温度场与速度场的协同性能逐渐增强，总熵产率和Be数逐渐减小，体积分数为0.5%~2.0%的Cu-H₂O的纳米流体在Re=8000~28000范围内的综合传热性能系数（PEC）分别达到2.16~2.25、3.16~3.25、3.94~4.15及4.64~5.16。Cu-H₂O、Al₂O₃-H₂O及CuO-H₂O这3种纳米流体相比，Cu-H₂O纳米流体的强化传热性能要远好于其他两种纳米流体，Al₂O₃-H₂O及CuO-H₂O纳米流体的平均PEC分别是Cu-H₂O纳米流体的0.47倍和0.46倍。随着Cu纳米颗粒粒径的增加，纳米流体的综合传热性能和温度场与速度场的协同性能逐渐减弱，总熵产率和Be数逐渐增加。

关键词: 静态混合器, 纳米流体, 总熵产, 协同数, 传热, 数值模拟

CLC Number:

TQ051.7

YU Yanfang, CHEN Yaxin, MENG Huibo, WANG Zongyong, WU Jianhua. Analysis of turbulent heat transfer characteristics of nanofluids in the Lightnin static mixer[J]. Chemical Industry and Engineering Progress, 2021, 40(S2): 30-39.

禹言芳, 陈雅鑫, 孟辉波, 王宗勇, 吴剑华. Lightnin静态混合器内纳米流体湍流传热特性分析[J]. 化工进展, 2021, 40(S2): 30-39.

Figures/Tables 12

References 35

1	LI Xiaoyan. Design of energy-conservation and emission-reduction plans of China's industry: evidence from three typical industries[J]. Energy, 2020, 209: 118358.
2	何盛宝. 新形势下我国化工行业的创新与发展[J]. 化工进展, 2021, 40(1): 1-5.
	HE Shengbao. Innovation and development of China's chemical industry against new situation[J]. Chemical Industry and Engineering Progress, 2021, 40(1): 1-5.
3	GHANEM A, LEMENAND T, DELLA VALLE D, et al. Static mixers: mechanisms, applications, and characterization methods—A review[J]. Chemical Engineering Research and Design, 2014, 92(2): 205-228.
4	THAKUR R K, VIAL C, NIGAM K D P, et al. Static mixers in the process industries—A review[J]. Chemical Engineering Research and Design, 2003, 81(7): 787-826.
5	LI H Z, FASOL C, CHOPLIN L. Hydrodynamics and heat transfer of rheologically complex fluids in a Sulzer SMX static mixer[J]. Chemical Engineering Science, 1996, 51(10): 1947-1955.
6	RAHMANI R K, KEITH T G, AYASOUFI A. Numerical study of the heat transfer rate in a helical static mixer[J]. Journal of Heat Transfer, 2006, 128(8): 769-783.
7	刘春江, 刘辉, 陆寒冰, 等. 新型管内插入物——立交盘强化传热的实验与模拟[J]. 化工学报, 2008, 59(2): 301-308.
	LIU Chunjiang, LIU Hui, LU Hanbing, et al. Heat transfer enhancement in round tube with cross over disk: experiment and simulation[J]. Journal of Chemical Industry and Engineering (China), 2008, 59(2): 301-308.
8	SIMÕES P C, AFONSO B, FERNANDES J, et al. Static mixers as heat exchangers in supercritical fluid extraction processes[J]. The Journal of Supercritical Fluids, 2008, 43(3): 477-483.
9	吴剑华, 张静, 张春梅, 等. 四叶片组合静态混合器湍流传热性能的数值模拟分析[J]. 过程工程学报, 2009, 9(1): 7-11.
	WU Jianhua, ZHANG Jing, ZHANG Chunmei, et al. Numerical simulation of turbulent flow and heat transfer in a four twisted elements static mixer[J]. The Chinese Journal of Process Engineering, 2009, 9(1): 7-11.
10	张静, 康铁鑫, 龚斌, 等. 双扭旋叶片组合形式对管内湍流换热性能的影响[J]. 化工学报, 2011, 62(S2): 52-60.
	ZHANG Jing, KANG Tiexin, GONG Bin, et al. Effect of combination method of double-twisted blades on turbulent convective heat transfer[J]. CIESC Journal, 2011, 62(S2): 52-60.
11	RAKOCZY R, MASIUK S, KORDAS M, et al. The effects of power characteristics on the heat transfer process in various types of motionless mixing devices[J]. Chemical Engineering and Processing: Process Intensification, 2011, 50(9): 959-969.
12	LEI Y G, ZHAO C H, SONG C F. Enhancement of turbulent flow heat transfer in a tube with modified twisted tapes[J]. Chemical Engineering & Technology, 2012, 35(12): 2133-2139.
13	MENG Huibo, ZHU Guangxue, YU Yanfang, et al. The effect of symmetrical perforated holes on the turbulent heat transfer in the static mixer with modified Kenics segments[J]. International Journal of Heat and Mass Transfer, 2016, 99: 647-659.
14	YU Yanfang, WANG Haiye, SONG Mingyuan, et al. The effects of element direction and intersection angle of adjacent Q-type inserts on the laminar flow and heat transfer[J]. Applied Thermal Engineering, 2016, 94: 282-295.
15	REGNER M, ÖSTERGREN K, TRÄGÅRDH C. Inﬂuence of viscosity ratio on the mixing process in a static mixer: numerical study[J]. Industrial & Engineering Chemistry Research, 2008, 47(9): 3030-3036.
16	MENG Huibo, HAN Mengqi, YU Yanfang, et al. Numerical evaluations on the characteristics of turbulent flow and heat transfer in the lightnin static mixer[J]. International Journal of Heat and Mass Transfer, 2020, 156: 119788.
17	KUMAR N, PURANIK B P. Numerical study of convective heat transfer with nanofluids in turbulent flow using a Lagrangian-Eulerian approach[J]. Applied Thermal Engineering, 2017, 111: 1674-1681.
18	PAKRAVAN H A, YAGHOUBI M. Analysis of nanoparticles migration on natural convective heat transfer of nanofluids[J]. International Journal of Thermal Sciences, 2013, 68: 79-93.
19	ALBOJAMAL A, VAFAI K. Analysis of single phase, discrete and mixture models, in predicting nanofluid transport[J]. International Journal of Heat and Mass Transfer, 2017, 114: 225-237.
20	ADIBI O, RASHIDI S, ABOLFAZLI ESFAHANI J. Effects of perforated anchors on heat transfer intensification of turbulence nanofluid flow in a pipe[J]. Journal of Thermal Analysis and Calorimetry, 2020, 141(5): 2047-2059.
21	HE Wei, TOGHRAIE D, LOTFIPOUR A, et al. Effect of twisted-tape inserts and nanofluid on flow field and heat transfer characteristics in a tube[J]. International Communications in Heat and Mass Transfer, 2020, 110: 104440.
22	ZHANG Aoyu, WANG Zhixiao, DING Guibin, et al. Numerical and experimental investigation on heat transfer characteristics of nanofluids in a circular tube with CDTE[J]. Heat and Mass Transfer, 2021, 57(8): 1329-1345.
23	MENTER F R, KUNTZ M, LANGTRY R. Ten years of industrial experience with the SST turbulence model[C]//Proceedings of the 4th International Symopslum on Turbulence, Heat and Mass Transfer, 2003: 625-632.
24	PAK B C, CHO Y I. Hydrodynamic and heat transfer study of dispersed fluids with submicron metallic oxide particles[J]. Experimental Heat Transfer, 1998, 11(2): 151-170.
25	LUNDGREN T S. Slow flow through stationary random beds and suspensions of spheres[J]. Journal of Fluid Mechanics, 1972, 51(2): 273-299.
26	HAMILTON R L, CROSSER O K. Thermal conductivity of heterogeneous two-component systems[J]. Industrial & Engineering Chemistry Fundamentals, 1962, 1(3): 187-191.
27	崔文政. 纳米流体强化动量与热量传递机理的分子动力学模拟研究[D]. 大连: 大连理工大学, 2013.
	CUI Wenzheng. Mechanism of momentum and heat transfer enhancement in nanofluids by molecular dynamics simulation[D]. Dalian: Dalian University of Technology, 2013.
28	KO T H, TING K. Entropy generation and optimal analysis for laminar forced convection in curved rectangular ducts: a numerical study[J]. International Journal of Thermal Sciences, 2006, 45(2): 138-150.
29	KOCK F, HERWIG H. Entropy production calculation for turbulent shear flows and their implementation in CFD codes[J]. International Journal of Heat and Fluid Flow, 2005, 26(4): 672-680.
30	HERWIG H, KOCK F. Direct and indirect methods of calculating entropy generation rates in turbulent convective heat transfer problems[J]. Heat and Mass Transfer, 2007, 43(3): 207-215.
31	李雅侠, 董国先, 吴剑华, 等. 反应釜内螺旋半圆管夹套内流体的湍流换热性能及熵产分析[J]. 过程工程学报, 2013, 13(4): 555-561.
	LI Yaxia, DONG Guoxian, WU Jianhua, et al. Analyses on turbulent heat transfer performance and entropy generation of fluid in the inner half coiled jacket[J]. The Chinese Journal of Process Engineering, 2013, 13(4): 555-561.
32	PAOLETTI S, RISPOLI F, SCIUBBA E. Calculation of exergetic losses in compact heat exchanger passages[J]. ASME HTD, 1989, 96: 711-716.
33	GUO Z Y, LI D Y, WANG B X. A novel concept for convective heat transfer enhancement[J]. International Journal of Heat and Mass Transfer, 1998, 41(14): 2221-2225.
34	GUO Z Y, TAO W Q, SHAH R K. The field synergy (coordination) principle and its applications in enhancing single phase convective heat transfer[J]. International Journal of Heat and Mass Transfer, 2005, 48(9): 1797-1807.
35	孟继安, 陈泽敬, 李志信, 等. 管内对流换热的场协同分析及换热强化[J]. 工程热物理学报, 2003, 24(4): 652-654.
	MENG Ji’an, CHEN Zejing, LI Zhixin, et al. Field coordination analysis and convection heat transfer enhancement in duct[J]. Journal of Engineering Thermophysics, 2003, 24(4): 652-654.

物质	颗粒粒径d_p/nm	颗粒形状	密度ρ/kg·m^-3	比热容c_p/J·kg·K^-1	黏度μ/Pa·s	材料热导率λ_m/W·m^-1·K^-1
水	—	—	998.2	4182	0.001003	0.6
Cu	50、75、100	球形	8978	381	—	387.6
CuO	100	球形	6510	540	—	18
Al₂O₃	100	球形	3880	773	—	36

物质	颗粒粒径d_p/nm	颗粒形状	密度ρ/kg·m^-3	比热容c_p/J·kg·K^-1	黏度μ/Pa·s	材料热导率λ_m/W·m^-1·K^-1
水	—	—	998.2	4182	0.001003	0.6
Cu	50、75、100	球形	8978	381	—	387.6
CuO	100	球形	6510	540	—	18
Al₂O₃	100	球形	3880	773	—	36

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