Toward accelerated latent heat storage, the unconstrained melting heat transfer in spherical capsules was revisited experimentally in the presence of nano-enhanced phase-change materials (NePCMs), with an emphasis on the influence of capsule size on the rates of melting, heat transfer, and latent heat storage. It was shown that increasing the size of the spherical capsule leads to two competing effects, i.e., thicker molten layer in the close-contact melting (CCM) region and stronger natural convection. However, the NePCM with a high loading (3 wt % graphite nanoplatelets (GNPs)) is not preferred for all capsule sizes as a result of the significantly deteriorated heat transfer in both CCM and natural convection, because the dramatic viscosity growth at such a high loading leads to increased thermal resistance across the molten layer and loss of natural convection that overweigh the increased thermal conductivity. The 1 wt % NePCM sample was exhibited to be able to facilitate latent heat storage for two cases, i.e., in the smallest capsule having a radius of 14.92 mm at a higher wall superheat of 30 °C and in the intermedium 24.85 mm capsule at a lower wall superheat of only 10 °C. It was suggested that a relatively low loading of a specific NePCM can cause a faster rate of latent heat storage over the baseline case of the matrix phase-change material (PCM), if the capsule size (and the wall superheat) can be adjusted properly to regulate the molten layer thickness and the intensity of natural convection.
Skip Nav Destination
Article navigation
July 2019
Research-Article
Unconstrained Melting Heat Transfer of Nano-Enhanced Phase-Change Materials in a Spherical Capsule for Latent Heat Storage: Effects of the Capsule Size
Nan Hu,
Nan Hu
School of Energy Engineering,
Institute of Thermal Science and
Power Systems,
Zhejiang University,
Hangzhou 310027, China
Institute of Thermal Science and
Power Systems,
Zhejiang University,
Hangzhou 310027, China
Search for other works by this author on:
Zi-Qin Zhu,
Zi-Qin Zhu
School of Energy Engineering,
Institute of Thermal Science and Power Systems,
Zhejiang University,
Hangzhou 310027, China
e-mail: 11327015@zju.edu.cn
Institute of Thermal Science and Power Systems,
Zhejiang University,
Hangzhou 310027, China
e-mail: 11327015@zju.edu.cn
Search for other works by this author on:
Zi-Rui Li,
Zi-Rui Li
School of Energy Engineering,
Institute of Thermal Science and
Power Systems,
Zhejiang University,
Hangzhou 310027, China
Institute of Thermal Science and
Power Systems,
Zhejiang University,
Hangzhou 310027, China
Search for other works by this author on:
Jing Tu,
Jing Tu
School of Energy Engineering,
Institute of Thermal Science and
Power Systems,
Zhejiang University,
Hangzhou 310027, China
Institute of Thermal Science and
Power Systems,
Zhejiang University,
Hangzhou 310027, China
Search for other works by this author on:
Li-Wu Fan
Li-Wu Fan
School of Energy Engineering,
Institute of Thermal Science and Power Systems,
Zhejiang University,
Hangzhou 310027, China;
State Key Laboratory of Clean Energy Utilization,
Zhejiang University,
Hangzhou 310027, China
e-mail: liwufan@zju.edu.cn
Institute of Thermal Science and Power Systems,
Zhejiang University,
Hangzhou 310027, China;
State Key Laboratory of Clean Energy Utilization,
Zhejiang University,
Hangzhou 310027, China
e-mail: liwufan@zju.edu.cn
Search for other works by this author on:
Nan Hu
School of Energy Engineering,
Institute of Thermal Science and
Power Systems,
Zhejiang University,
Hangzhou 310027, China
Institute of Thermal Science and
Power Systems,
Zhejiang University,
Hangzhou 310027, China
Zi-Qin Zhu
School of Energy Engineering,
Institute of Thermal Science and Power Systems,
Zhejiang University,
Hangzhou 310027, China
e-mail: 11327015@zju.edu.cn
Institute of Thermal Science and Power Systems,
Zhejiang University,
Hangzhou 310027, China
e-mail: 11327015@zju.edu.cn
Zi-Rui Li
School of Energy Engineering,
Institute of Thermal Science and
Power Systems,
Zhejiang University,
Hangzhou 310027, China
Institute of Thermal Science and
Power Systems,
Zhejiang University,
Hangzhou 310027, China
Jing Tu
School of Energy Engineering,
Institute of Thermal Science and
Power Systems,
Zhejiang University,
Hangzhou 310027, China
Institute of Thermal Science and
Power Systems,
Zhejiang University,
Hangzhou 310027, China
Li-Wu Fan
School of Energy Engineering,
Institute of Thermal Science and Power Systems,
Zhejiang University,
Hangzhou 310027, China;
State Key Laboratory of Clean Energy Utilization,
Zhejiang University,
Hangzhou 310027, China
e-mail: liwufan@zju.edu.cn
Institute of Thermal Science and Power Systems,
Zhejiang University,
Hangzhou 310027, China;
State Key Laboratory of Clean Energy Utilization,
Zhejiang University,
Hangzhou 310027, China
e-mail: liwufan@zju.edu.cn
Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received October 6, 2018; final manuscript received April 17, 2019; published online May 14, 2019. Assoc. Editor: Gennady Ziskind.
J. Heat Transfer. Jul 2019, 141(7): 072301 (8 pages)
Published Online: May 14, 2019
Article history
Received:
October 6, 2018
Revised:
April 17, 2019
Citation
Hu, N., Zhu, Z., Li, Z., Tu, J., and Fan, L. (May 14, 2019). "Unconstrained Melting Heat Transfer of Nano-Enhanced Phase-Change Materials in a Spherical Capsule for Latent Heat Storage: Effects of the Capsule Size." ASME. J. Heat Transfer. July 2019; 141(7): 072301. https://doi.org/10.1115/1.4043621
Download citation file:
Get Email Alerts
Cited By
A Comparative Study of Thermoconvective Flows of a Newtonian Fluid Over Three Horizontal Undulated Surfaces in a Porous Medium
J. Heat Transfer (September 2022)
Related Articles
Numerical and Experimental Investigation on a Combined Sensible and Latent Heat Storage Unit Integrated With Solar Water Heating System
J. Sol. Energy Eng (November,2009)
Latent Heat Storage: Container Geometry, Enhancement Techniques, and Applications—A Review
J. Sol. Energy Eng (October,2019)
Energy and Exergy Analyses of Simultaneous Charging and Discharging Latent Heat Storage System at Different Inclination Angles—An Experimental Study
J. Energy Resour. Technol (July,2021)
Development of PCM Storage for Process Heat and Power Generation
J. Sol. Energy Eng (November,2009)
Related Proceedings Papers
Related Chapters
Numerical Analysis of a Latent Heat Storage Heat Exchanger Considering the Effect of Natural Convection
Inaugural US-EU-China Thermophysics Conference-Renewable Energy 2009 (UECTC 2009 Proceedings)
Numerical Study on Dynamic Discharging Performance of Packed Bed Using Spherical Capsules Containing N-Tetradecane
Inaugural US-EU-China Thermophysics Conference-Renewable Energy 2009 (UECTC 2009 Proceedings)
Numerical Study on Dynamic Charging Performance of Packed Bed Using Spherical Capsules Containing N-Tetradecane
Inaugural US-EU-China Thermophysics Conference-Renewable Energy 2009 (UECTC 2009 Proceedings)