Abstract
Efficient and rational use of thermal energy requires the design and development of suitable and cost-effective latent heat storage systems. In this study, a novel curved thermal storage unit is put forward and its thermal behavior has been numerically compared with the traditional rectangular PCM-based thermal storage unit. The solid–liquid interface evolution, liquid flow pattern and temperature distribution are presented. Transient Nu at the heating wall and full melting time are also calculated. The numerical results show the high impact of the enclosure geometry on melting and nature convection. A reduction of 30.6 % in thermal storage time has been achieved by changing the unit from rectangular to curve. Moreover, parametric studies are conducted to assess how thermal performance of the units is affected by the heating wall temperature and PCM thermal conductivity. Correlations encompassing a wide range of parameters are developed in terms of full melting time. Results indicate that proportion of full melting time reduced for the curved unit is almost a constant value and does not vary significantly with these factors. All these may be very helpful for the design of more efficient thermal storage units.
Similar content being viewed by others
References
Bayón R, Rojas E, Valenzuela L, Zarza E, León J. Analysis of the experimental behaviour of a 100 kWth latent heat storage system for direct steam generation in solar thermal power plants. Appl Therm Eng. 2010;30:2643–51.
Shon J, Kim H, Lee K. Improved heat storage rate for an automobile coolant waste heat recovery system using phase-change material in a fin-tube heat exchanger. Appl Energy. 2014;113:680–9.
Mahmoud S, Tang A, Toh C, AL-Dadah R, Soo SL. Experimental investigation of inserts configurations and PCM type on the thermal performance of PCM based heat sinks. Appl Energy. 2013;112:1349–56.
Jeon J, Lee JH, Seo J, Jeong SG, Kim S. Application of PCM thermal energy storage system to reduce building energy consumption. J Therm Anal Calorim. 2013;111:279–88.
Fan L, Khodadadi JM. Thermal conductivity enhancement of phase change materials for thermal energy storage: a review. Renew Sustain Energy Rev. 2011;15:24–46.
Jegadheeswaran S, Pohekar SD. Performance enhancement in latent heat thermal storage system: a review. Renew Sustain Energy Rev. 2009;13:2225–44.
Ho CJ, Viskanta R. Heat transfer during melting from an isothermal vertical wall. J Heat Trans ASME. 1984;106:12–9.
Gau C, Viskanta R. Melting and solidification of a pure metal on a vertical wall. J Heat Trans ASME. 1986;108:174–81.
Wang Y, Amiri A, Vafai K. An experimental investigation of the melting process in a rectangular enclosure. Int J Heat Mass Transf. 1999;42:3659–72.
Dhaidan NS, Khodadadi JM, Al-Hattab A, Al-Mashat M. Experimental and numerical investigation of melting of phase change material/nanoparticle suspensions in a square container subjected to a constant heat flux. Int J Heat Mass Transf. 2013;66:672–83.
Shokouhmand H, Kamkari B. Experimental investigation on melting heat transfer characteristics of lauric acid in a rectangular thermal storage unit. Exp Therm Fluid Sci. 2013;50:201–12.
Omari KE, Kousksou T, Guer YL. Impact of shape of container on natural convection and melting inside enclosures used for passive cooling of electronic devices. Appl Therm Eng. 2011;31:3022–35.
Darzi AR, Farhadi M, Sedighi K. Numerical study of melting inside concentric and eccentric horizontal annulus. Appl Math Model. 2012;36:4080–6.
Akgün M, Aydın O, Kaygusuz K. Thermal energy storage performance of paraffin in a novel tube-in-shell system. Appl Therm Eng. 2008;28:405–13.
Koizumi H, Jin Y. Performance enhancement of a latent heat thermal energy storage system using curved-slab containers. Appl Therm Eng. 2012;37:145–53.
Voller VR, Prakash C. A fixed grid numerical modelling methodology for convection–diffusion mushy region phase-change problems. Int J Heat Mass Transf. 1987;30:1709–19.
Hannoun N, Alexiades V, Mai TZ. A reference solution for phase change with convection. Int J Numer Methods Fluids. 2005;48:1283–308.
Pal D, Joshi YK. Melting in a side heated tall enclosure by a uniformly dissipating heat source. Int J Heat Mass Transf. 2001;44:375–87.
Sarı A, Karaipekli A, Alkan C. Preparation, characterization and thermal properties of lauric acid/expanded perlite as novel form-stable composite phase change material. Chem Eng. 2009;155:899–904.
Chen Z, Shan F, Cao L, Fang G. Synthesis and thermal properties of shape-stabilized lauric acid/activated carbon composites as phase change materials for thermal energy storage. Sol Energy Mater Sol Cells. 2012;102:131–6.
Acknowledgements
Support from the National Science and Technology Supporting Program (No. 2011BAJ03B03) in this study is gratefully acknowledged.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Hu, Z., Li, A., Gao, R. et al. A comparison study on melting inside the rectangular and curved unit with a vertical heating wall. J Therm Anal Calorim 122, 831–842 (2015). https://doi.org/10.1007/s10973-015-4754-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10973-015-4754-2