محاسبۀ ضریب هدایت حرارتی نانو سیال آب و TiO2 با مدل‌های مختلف

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشگاه صنعتی سهند

چکیده

هدایت حرارتی یکی از خواص ماده و بیان‌گر توانایی ماده در هدایت گرما است. به‌معنای دیگر، هدایت حرارتی اندازه‌گیری تمایل طبیعی ماده به پراکندگی انرژی در زمانی است‌که در اثر تحمیل یک گرادیان دمایی، حالت تعادل مختل می‌شود؛ لذا نقش چشم‌گیری در مسائل انتقال حرارت دارد. یکی از راهکارهای ارتقای هدایت حرارتی سیال، استفاده از نانوسیالات می‌باشد. به‌علت کاربردهای گستردۀ مواد نانومقیاس، در کاربردهای حرارتی و اهمیت تعیین هدایت حرارتی نانوسیالات، در این تحقیق به بررسی یازده‌مدل برای پیش‌بینی هدایت حرارتی نانوسیالات (سیستم حاوی آب و نانوذرات TiO2) و مقایسۀ نتایج محاسبات با نتایج آزمایشگاهی موجود در مقالات پرداخته شده‌است. بر این‌اساس، مشخص شد که نسبت ضریب هدایت حرارتی مؤثر (ضریب هدایت حرارتی مخلوط سیال پایه و نانو‌ ذره) به ضریب هدایت حرارتی سیال پایه (keff/kf) در حالتی‌که مقدار حجمی نانوذره توزیع شده در سیال پایه در حدود 1 الی 3 درصد حجمی باشد، در محدودۀ 01/1 تا 1/1 می‌باشد، به‌عبارت دیگر، افزودن نانوذره در محدودۀ 1 الی 3 درصد حجمی، این توانایی را دارد که نسبت keff/kf را تا 1/1 (یا 10درصد) ارتقا دهد و توانایی هدایت حرارتی مجوعۀ سیال پایه و نانوذره در مقایسه با سیال پایه تا 10 درصد افزایش یابد. هم‌چنین افزایش قطر نانوذرات میزان بهبود ضریب هدایت حرارتی را کاهش می­دهد.

کلیدواژه‌ها


عنوان مقاله [English]

Calculation of the Thermal Conductivity Coefficient of Water and TiO2 Nanofluid with Different Models

نویسندگان [English]

  • S. M. Sajjadi
  • A. Tavakoli
Sahand University of Technology
چکیده [English]

Thermal conductivity is defined as the ability of a material to heat transfer. In other words, thermal conductivity is the natural tendency of material to energy dispersion when temperature equilibrium disturbed by the imposition of a temperature gradient. Therefore, it plays a significant role in the issues of heat transfer. Due to the various applications of nanoscale materials in heat transfer and the importance of determining the thermal conductivity of nanofluids, this study, investigates eleven models for predicting the thermal conductivity of nanofluids (includes water and TiO2 nanoparticles) and comparing the results of calculations with the experimental results in the articles. Based on this study, it was found that the effective thermal conductivity ratio (thermal conductivity of the mixture of basic fluid and distributed nanoparticle) to the basic fluid conductivity (keff/kf) for variable Volumetric percentages ranging from 0.01 to 0.03 varies between 1.01 and 1.1. In the other words, addition of nanoparticles in the range of 1 to 3 Volume percentage is able to promote the keff/kf to 1.1 (10%). Therefore, thermal conductivity of the mixture of basic fluid and distributed nanoparticle increases up to 10% compared with basic fluid. Also, increasing the diameter of the nanoparticles reduces the thermal conductivity improvement.

کلیدواژه‌ها [English]

  • Heat Transfer
  • Thermal Conductivity Modeling
  • Nanofluid
  • Nanoparticles
 
 
[1]     Choi, S. U. S., Eastman, J. A., "Enhancing thermal conductivity of fluids with nanoparticles," presented at the ASME International Mechanical Engineering Congress and Exposition, San Francisco, California, (1995).
[2]     Murshed, S. M. S., Leong, K. C., Yang, C., "Enhanced thermal conductivity of TiO2-water based nanofluids," Int. J. Therm. Sci., Vol. 44, pp. 367-373, (2005).
[3]     Tawfik, M. M., "Experimental studies of nanofluid thermal conductivity enhancement and applications: A review," Renew. Sustain. Energy Rev., Vol. 75, pp. 1239-1253, (2017).
[4]     Maheshwary, P. B., Handa, C. C., Nemade, K. R., "A comprehensive study of effect of concentration, particle size and particle shape on thermal conductivity of titania/water based nanofluid," Appl. Therm. Eng., Vol. 119, pp. 79-88, (2017).
[5]     Ahmadi, M. H., Mirlohi, A., Alhuyi Nazari, M., Ghasempour, R., "A review of thermal conductivity of various nanofluids," J. Mol. Liq., Vol. 265, pp. 181-188, (2018).
[6]     Yu, W., France, D. M., Routbort, J. L., Choi, S. U. S., "Review and Comparison of Nanofluid Thermal Conductivity and Heat Transfer Enhancements," Heat Transfer Eng., Vol. 29, pp. 432-460, (2008).
[7]     Ruan, J., Wang, K., Song, H., Xu, X., Ji, J., Cui, D., "Biocompatibility of hydrophilic silica-coated CdTe quantum dots and magnetic nanoparticle," Nanoscale Res Lett., Vol. 6, pp. 1-13, (2011).
[8]     Das, S. K., Putra, N., Thiesen, P., Roetzel, W., "Temperature Dependence of Thermal Conductivity Enhancement for Nanofluids," J Heat Transf., Vol. 125, pp. 567-574, (2003).
[9]     Xuan, Y., Li, Q., Hu, W., "Aggregation structure and thermal conductivity of nanofluids," AIChE Journal, Vol. 49, pp. 1038-1043, (2003).
[10]   Eastman, J. A., Choi, S. U. S., Li, S., Yu, W., Thompson, L. J., "Anomalously increased effective thermal conductivities of ethylene glycol-based nanofluids containing copper nanoparticles," Appl. Phys. Lett., Vol. 78, pp. 718-720, (2001).
[11]   Eastman, J. A., Choi, U. S., Li, S., Thompson, L. J., Lee, S., "Enhanced Thermal Conductivity through the Development of Nanofluids," MRS Online Proceedings Library Archive, Vol. 457, p. 3, (1996).
[12]   Lee, S., Choi, S. U. S., Li, S., Eastman, J. A., "Measuring Thermal Conductivity of Fluids Containing Oxide Nanoparticles," J Heat Transf, Vol. 121, pp. 280-289, (1999).
[13]   Wang, X. Q., Mujumdar, A. S., "Heat transfer characteristics of nanofluids: a review," Int. J. Therm. Sci., Vol. 46, pp. 1-19, (2007).
 
[14]   Maxwell, J. C., "A treatise on electricity and magnetism. Vol. 1", 1th ed, Clarendon press, Oxford, London, p. 489, (1873).
[15]   Hamilton, R. L., Crosser, O. K., "Thermal Conductivity of Heterogeneous Two-Component, " Systems, I&EC Fundamentals, Vol. 1, pp. 182-191, (1962).
[16]   Yu, W., Choi, S. U. S., "The Role of Interfacial Layers in the Enhanced Thermal Conductivity of Nanofluids: A Renovated Maxwell Model," ‎J. Nanoparticle Res., Vol. 5, pp. 167-171, (2003).
[17]   Duangthongsuk, W., Wongwises, S., "Measurement of temperature-dependent thermal conductivity and viscosity of TiO2-water nanofluids," Exp Therm Fluid Sci., Vol. 33, pp. 706-714, (2009).
[18]   Xue, Q. Z., "Model for thermal conductivity of carbon nanotube-based composites," Physica B Condens. Matter, Vol. 368, pp. 302-307, (2005).
[19]   Davis, R. H., "The effective thermal conductivity of a composite material with spherical inclusions," Int. J. Thermophys., Vol. 7, pp. 609-620, (1986).
[20]   Abbasian Arani, A. A., Amani, J., "Experimental investigation of diameter effect on heat transfer performance and pressure drop of TiO2-water nanofluid," Exp Therm Fluid Sci., Vol. 44, pp. 520-533, (2013).
[21]   Corcione, M., "Empirical correlating equations for predicting the effective thermal conductivity and dynamic viscosity of nanofluids," Energy Convers. Manag., Vol. 52, pp. 789-793, (2011).
[22]   Bruggeman, D. A. G., "Berechnung verschiedener physikalischer Konstanten von heterogenen Substanzen. I. Dielektrizitatskonstanten und Leitfahigkeiten der Mischkörper aus isotropen Substanzen," Ann. Phys., Vol. 416, pp. 636-664, (1935).
[23]   Wasp, E. J., Kenny, J. P., Gandhi, R. L., "Solid–liquid slurry pipeline transportation," Trans. Tech. publication, Clausthal, Germany, (1977).
[24]   Jeffrey, D. J., "Conduction through a Random Suspension of Spheres," P Roy Soc A-Math Phy., Vol. 335, pp. 355-367, (1973).
[25]   Timofeeva, E. V., Gavrilov, A. N., McCloskey, J. M., Tolmachev, Y. V., Sprunt, S., Lopatina, L. M., Selinger, J. V., "Thermal conductivity and particle agglomeration in alumina nanofluids: Experiment and theory," Phys. Rev. E, Vol. 76, pp. 061203(1-16), (2007).
[26]   Lu, S. Y., Lin, H. C., "Effective conductivity of composites containing aligned spheroidal inclusions of finite conductivity," J. Appl. Phys., Vol. 79, pp. 6761-6769, (1996).
 
[27]   Xue, Q., Xu, W. M., "A model of thermal conductivity of nanofluids with interfacial shells," Mater. Chem. Phys, Vol. 90, pp. 298-301, (2005).
[28]   Xie, H., Fujii, M., Zhang, X., "Effect of interfacial nanolayer on the effective thermal conductivity of nanoparticle-fluid mixture," Int. J. Heat Mass Transf., Vol. 48, pp. 2926-2932, (2005).
[29]   Longo, G. A., Zilio, C., "Experimental measurement of thermophysical properties of oxide water nano-fluids down to ice-point," Exp Therm Fluid Sci., Vol. 35, pp. 1313-1324, (2011).
[30]   He, Y., Jin, Y., Chen, H., Ding, Y., Cang, D., Lu, H., "Heat transfer and flow behaviour of aqueous suspensions of TiO2 nanoparticles (nanofluids) flowing upward through a vertical pipe," Int. J. Heat Mass Transf., Vol. 50, pp. 2272-2281, (2007).
[31]   Zhang, X., Gu, H., Fujii, M., "Effective thermal conductivity and thermal diffusivity of nanofluids containing spherical and cylindrical nanoparticles," Exp Therm Fluid Sci., Vol. 31, pp. 593-599, (2007).
 
[32]   Masuda, H., Ebata, A., Teramae, K., Hishinuma, N., "Alteration of Thermal Conductivity and Viscosity of Liquid by Dispersing Ultra-Fine Particles Dispersion of Al2O3, SiO2 and TiO2 Ultra-Fine Particles," Netsu Bussei, Vol. 7, pp. 227-233, (1993).
[33]   Duangthongsuk, W., Wongwises, S., "An experimental study on the heat transfer performance and pressure drop of TiO2-water nanofluids flowing under a turbulent flow regime," Int. J. Heat Mass Transf., Vol. 53, pp. 334-344, (2010).
[34]   Yoo, D. H., Hong, K. S., Yang, H. S., "Study of thermal conductivity of nanofluids for the application of heat transfer fluids," Thermochimica Acta, Vol. 455, pp. 66-69, (2007).
[35] Kleinstreue, C., Y. Feng, Y., "Experimental and theoretical studies of nanofluid thermal conductivity enhancement: a review," Nanoscale Res Lett., Vol. 6, p. 229, (2011).