Size Effect of Graphene Nanoparticles on the Thermal Properties of the Doped Phase Change Materials

Abstract

In this study, the size effects of the Graphene nanoparticles (GNP) doped into a paraffin type organic phase change material (PCM) on thermal properties were examined. The thermal conductivities, melting/solidification temperatures and melting/solidification latent heats of the GNP/PCM composites, which were obtained by incorporating GNP nanoparticles with three different sizes into an organic PCM in mass fractions of 1%, 3% and 5%, were measured. The changes obtained in thermal properties were determined by referring to the non-doped PCM data. The results obtained showed that in low PCM mass fractions, thermal conductivity enhancement was a function of both surface area and thickness of the GNP nanoparticles. In addition, it was determined that thicker nanoparticles formed a more efficient conduction network at high PCM fractions. The reflections of the enhancements obtained in thermal conductivity on thermal performance were also determined in the study.  Enhancements in thermal conductivity depending on the increase in thickness of GNP were obtained as 6.3%, 107.5% and 113.7% for 5% GNP(1-5nm)/ PCM, 5% GNP(6-8nm)/PCM and 5% GNP(11-15nm)/PCM composites, respectively. These thermal conductivity enhancements resulted performance increase in the energy storage unit around 5.5%, 18.3% and 20% respectively.

Keywords

• PCM,Thermal conductivity,Size effect,Graphene,Nanoparticles

Grafen Nanoparçacık Boyutunun Katkılı Faz Değişken Malzemelerin Termal Özelliklerine Etkisi

Abstract

Bu çalışmada, parafin tipi bir organik Faz Değişken Malzeme (FDM) içerisine katkılanan Grafen nanoparçacık boyutunun termal özellikler üzerindeki etkileri incelenmiştir. Üç farklı boyuta sahip GNP nanoparçacıkların organik bir FDM içerisine %1, %3 ve %5 kütle bölüntülerinde katkılanması suretiyle elde edilen GNP/FDM kompozitlerinin ısıl iletkenlik, erime/katılaşma sıcaklıkları ve erime/katılaşma gizli ısıları ölçülmüştür. Termal özelliklerde elde edilen değişimler katkılanmamış FDM verileri referans alınarak belirlenmiştir. Elde edilen sonuçlar, düşük GNP kütle bölüntülerinde ısıl iletkenlik iyileştirmesinin hem GNP nanoparçacık yüzey alanının hem de kalınlığının bir fonksiyonu olduğunu göstermiştir. Buna ilave olarak, daha kalın nanoparçacıkların yüksek FDM kütle bölüntülerinde daha etkin bir iletim ağı oluşturdukları belirlenmiştir. Çalışmada ayrıca ısıl iletkenlikte elde edilen iyileştirmelerin termal performansa yansımaları da belirlenmiştir. GNP nanoparçacık kalınlığındaki artışa bağlı olarak ısıl iletkenlikteki iyileşmeler; 5% GNP(1-5nm)/ FDM, 5% GNP(6-8nm)/FDM ve 5% GNP(11-15nm)/FDM kompozitleri için sırasıyla %6.3, %107.5 ve  %113.7 olarak elde edilmiştir. Bu ısıl iletkenlik iyileştirmeleri, bir enerji depolama biriminde sırasıyla %5.5,% 18.3 ve % 20 civarında performans artışı sağlamıştır.

Keywords

• FDM,Isıl İletkenlik,Boyut Etkisi,Grafen Nanoparçacık

References

1. L. Liu, D. Su, Y. Tang, and G. Fang, “Thermal conductivity enhancement of phase change materials for thermal energy storage: A review,” Renew. Sustain. Energy Rev., vol. 62, pp. 305–317, 2016.
2. J. P. Hadiya and A. K. N. Shukla, “Experimental thermal behavior response of paraffin wax as storage unit,” J. Therm. Anal. Calorim., vol. 124, no. 3, pp. 1511–1518, 2016.
3. N. Lorwanishpaisarn, P. Kasemsiri, P. Posi, and P. Chindaprasirt, “Characterization of paraffin/ultrasonic-treated diatomite for use as phase change material in thermal energy storage of buildings,” J. Therm. Anal. Calorim., vol. 128, no. 3, pp. 1293–1303, 2017.
4. D. Zhou, C. Y. Zhao, and Y. Tian, “Review on thermal energy storage with phase change materials (PCMs) in building applications,” Appl. Energy, vol. 92, pp. 593–605, 2012.
5. Y. Yuan, T. Li, N. Zhang, X. Cao, and X. Yang, “Investigation on thermal properties of capric–palmitic–stearic acid/activated carbon composite phase change materials for high-temperature cooling application,” J. Therm. Anal. Calorim., vol. 124, pp. 881-888, 2016.
6. S. Al Hallaj and J. R. Selman, “A Novel Thermal Management System for Electric Vehicle Batteries Using Phase-Change Material,” J. Electrochem. Soc., vol. 147, pp. 3231-3236, 2000.
7. S. A. Khateeb, M. M. Farid, J. R. Selman, and S. Al-Hallaj, “Design and simulation of a lithium-ion battery with a phase change material thermal management system for an electric scooter,” J. Power Sources, vol. 128, pp. 292-307, 2004.
8. C. V. Hémery, F. Pra, J. F. Robin, and P. Marty, “Experimental performances of a battery thermal management system using a phase change material,” J. Power Sources, vol. 270, pp. 349-358, 2014.

9. U. Stritih, “An experimental study of enhanced heat transfer in rectangular PCM thermal storage,” Int. J. Heat Mass Transf., vol. 47, pp. 2841-2847,2004.
10. F. Agyenim, P. Eames, and M. Smyth, “A comparison of heat transfer enhancement in a medium temperature thermal energy storage heat exchanger using fins,” Sol. Energy, vol. 83, pp. 1509-1520, 2009.
11. M. Xiao, B. Feng, and K. Gong, “Preparation and performance of shape stabilized phase change thermal storage materials with high thermal conductivity,” Energy Convers. Manag., vol.43, pp. 103-108, 2002.
12. J. Yang, L. Yang, C. Xu, and X. Du, “Experimental study on enhancement of thermal energy storage with phase-change material,” Appl. Energy, vol. 169, pp. 164-176, 2016.
13. J. F. Wang, H. Q. Xie, Y. Li, and Z. Xin, “PW based phase change nanocomposites containing gamma-Al(2)O(3),” J. Therm. Anal. Calorim., vol. 102, pp.709-713, 2010.
14. C. J. Ho and J. Y. Gao, “Preparation and thermophysical properties of nanoparticle-in-paraffin emulsion as phase change material,” Int. Commun. Heat Mass Transf., vol. 36, pp. 467-470, 2009.
15. Ü. N. Temel and B. Y. ÇİFTÇİ, “Determination of Thermal Properties of A82 Organic Phase Change Material Embedded with Different Type Nanoparticles,” Isı Bilimi ve Tekniği Dergisi Vol. 38 pp. 75–85, 2018.
16. J. Wang, H. Xie, Z. Xin, and Y. Li, “Increasing the thermal conductivity of palmitic acid by the addition of carbon nanotubes,” Carbon N. Y., vol. 48, pp. 3979-3986, 2010.
17. Z. T. Yu et al., “Increased thermal conductivity of liquid paraffin-based suspensions in the presence of carbon nano-additives of various sizes and shapes,” Carbon N. Y., vol. 53, pp. 277-285, 2013.
18. L. W. Fan et al., “Effects of various carbon nanofillers on the thermal conductivity and energy storage properties of paraffin-based nanocomposite phase change materials,” Appl. Energy, vol. 110, pp. 163-172, 2013.
19. Y. Cui, C. Liu, S. Hu, and X. Yu, “The experimental exploration of carbon nanofiber and carbon nanotube additives on thermal behavior of phase change materials,” Sol. Energy Mater. Sol. Cells, vol. 95, pp. 1208-1212, 2011.
20. J. N. Shi et al., “Improving the thermal conductivity and shape-stabilization of phase change materials using nanographite additives,” Carbon N. Y.,vol. 51, pp. 365-372, 2013.
21. J. Wang, H. Xie, and Z. Xin, “Thermal properties of paraffin based composites containing multi-walled carbon nanotubes,” Thermochim. Acta, vol. 488, pp. 39-42, 2009.
22. J. Wang, H. Xie, Z. Xin, Y. Li, and L. Chen, “Enhancing thermal conductivity of palmitic acid based phase change materials with carbon nanotubes as fillers,” Sol. Energy, vol. 84, pp. 339-344, 2010.