Experimental investigation on melting heat transfer characteristics of lauric acid in a rectangular thermal storage unit

Abstract This paper presents an experimental effort to visualize temperature field and melt front evolution during solid–liquid phase change process. The study is focused on the melting of lauric acid in a rectangular thermal storage unit heated from one side. Thermophysical properties of lauric acid are determined and found to be desirable for application as a medium temperature phase change material (PCM). Image processing of photographs together with recorded temperatures are used to calculate the melt fractions, temporal heat storage and heat transfer characteristics, including the average Nusselt number on the hot wall as well as the local heat transfer rates on the melt front. Moreover, solid–liquid interface morphology and temperature field are employed to infer dominant heat transfer mechanisms and time-dependent flow structures during different stages of the melting process. Results indicate that during the initial stage of melting, heat conduction is the dominant mode of heat transfer, followed by transition from conduction to convection regime and convection dominated heat transfer at later times. Approaching the end of the melting process, bulk temperature of the liquid PCM increases and stratified temperature field appears at upper part of the enclosure which reveals depression of the convection currents.

[1]  S. C. Solanki,et al.  Latent heat thermal energy storage using cylindrical capsule: Numerical and experimental investigations , 2006 .

[2]  E. Onder,et al.  Organic phase change materials and their textile applications: An overview , 2012 .

[3]  Dan Zhou,et al.  Review on thermal energy storage with phase change materials (PCMs) in building applications , 2012 .

[4]  Zhaolin Gu,et al.  Thermal energy recovery of air conditioning system¿¿heat recovery system calculation and phase change materials development , 2004 .

[5]  Y. Wang,et al.  An experimental investigation of the melting process in a rectangular enclosure , 1999 .

[6]  R. Velraj,et al.  Experimental investigation on heat recovery from diesel engine exhaust using finned shell and tube heat exchanger and thermal storage system , 2011 .

[7]  Yvan Dutil,et al.  Experimental study of small-scale solar wall integrating phase change material , 2012 .

[8]  F. L. Tan,et al.  Cooling of mobile electronic devices using phase change materials , 2004 .

[9]  G. Ziskind,et al.  Melting in a vertical cylindrical tube: Numerical investigation and comparison with experiments , 2010 .

[10]  Gennady Ziskind,et al.  Numerical and experimental study of melting in a spherical shell , 2007 .

[11]  Brian Norton,et al.  Evaluation of phase change materials for thermal regulation enhancement of building integrated photovoltaics , 2010 .

[12]  R. Viskanta,et al.  Solidification of a pure metal at a vertical wall in the presence of liquid superheat , 1988 .

[13]  K. Sopian,et al.  Review of solar air collectors with thermal storage units , 2011 .

[14]  Kadhim H. Suffer,et al.  A storage domestic solar hot water system with a back layer of phase change material , 2013 .

[15]  S. J. Kline,et al.  Describing Uncertainties in Single-Sample Experiments , 1953 .

[16]  Chie Gau,et al.  Effect of natural convection on solidification from above and melting from below of a pure metal , 1985 .

[17]  Chie Gau,et al.  Melting and Solidification of a Pure Metal on a Vertical Wall , 1986 .

[18]  A. Sharma,et al.  Review on thermal energy storage with phase change materials and applications , 2009 .

[19]  Liwu Fan,et al.  Experimental and computational study of constrained melting of phase change materials (PCM) inside a spherical capsule , 2009 .

[20]  F. L. Tan,et al.  Constrained and unconstrained melting inside a sphere , 2008 .

[21]  A. Bontemps,et al.  Experimental and modelling study of twin cells with latent heat storage walls , 2011 .

[22]  Dominique Gobin,et al.  Melting in Rectangular Enclosures: Experiments and Numerical Simulations , 1985 .

[23]  Jian Zhang,et al.  Preparation and thermal performance of gypsum boards incorporated with microencapsulated phase change materials for thermal regulation , 2012 .

[24]  Chih-Chung Chang,et al.  Heat pipe with PCM for electronic cooling , 2011 .

[25]  F. Tan,et al.  Cooling of portable hand-held electronic devices using phase change materials in finned heat sinks , 2010 .

[26]  F. L. Tan,et al.  An experimental study of n-octadecane melting inside a sphere subjected to constant heat rate at surface , 2012 .

[27]  Gajanana C. Birur,et al.  NASA thermal control technologies for robotic spacecraft , 2003 .