Improving heat transfer in a triplex tube heat exchanger containing phase-change materials by modifications of length and position of fins

Document Type : Article


Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran.


Heat thermal energy storage is a technique to improve thermal efficiency through reducing discrepancy between energy demand and supply. Latent heat thermal energy storage as a kind of thermal energy storage method has drawn considerable attention from researchers due to its high thermal energy density and constant operating temperature. This study numerically investigates the melting process in a triplex tube heat exchanger containing phase change material (PCM) RT82. A two-dimensional numerical model has been generated using the Ansys Fluent 16 software program to simulate melting process. In this study, conduction and natural convection have been considered. Selected arrangements of rectangular fins, including lengths and positions, were selected according to heat distribution while the total area of fins was kept constant. This new strategy was done to improve heat transfer in PCM which would result in decreasing its melting time. The select optimized model in this article reduces meting time to 28.4% in comparison with the model in Ref. [1]. Numerical results have been validated by numerical and experimental results of this reference and there has been a proper agreement between them.


Main Subjects

1 Mat, S., Al-Abidi, A.A., Sopian, K., et al. Enhance  heat transfer for PCM melting in triplex tube with  internal-external _ns", Energy Conversion and Management,  74, pp. 223{236 (2013).  2 Ghoneim, A. Comparison of theoretical models of  phase-change and sensible heat storage for air and  water-based solar heating systems", Solar Energy, 42,  pp. 209{220 (1989).  3 Agyenim, F., Hewitt, N., Eames, P., et al. A review  of materials, heat transfer and phase change problem  formulation for latent heat thermal energy storage systems  (LHTESS)", Renewable and Sustainable Energy  Reviews, 14, pp. 615{628 (2010).  4 Caliskan, H., Dincer, I., and Hepbasli, A. Thermodynamic  analyses and assessments of various thermal  energy storage systems for buildings", Energy Conversion  and Management, 62, pp. 109{122 (2012).  5 Khudhair, A.M. and Farid, M.M. A review on energy  conservation in building applications with thermal  storage by latent heat using phase change materials",  Energy Conversion and Management, 45, pp. 263{275  (2004).  6 Mazman, M., Cabeza, L.F., Mehling, H., et al. Utilization  of phase change materials in solar domestic hot  water systems", Renewable Energy, 34, pp. 1639{1643  (2009).  7 Zalba, B., Mar__n, J.M., Cabeza, L.F., et al. Freecooling  of buildings with phase change materials",  International Journal of Refrigeration, 27, pp. 839{  849 (2004).  8 Benli, H. Energetic performance analysis of a groundsource  heat pump system with latent heat storage  for a greenhouse heating", Energy Conversion and  Management, 52, pp. 581{589 (2011).  9 Jaworski, M. Thermal performance of heat spreader  for electronics cooling with incorporated phase change  material", Applied Thermal Engineering, 35, pp. 212{  219 (2012).  10 Wang, Y.H. and Yang, Y.T. Three-dimensional transient  cooling simulations of a portable electronic device  using PCM (phase change materials) in multi-_n heat  sink", Energy, 36, pp. 5214{5224 (2011).  11 Pandiyarajan, V., Pandian, M.C., Malan, E., et al.  Experimental investigation on heat recovery from  diesel engine exhaust using _nned shell and tube  heat exchanger and thermal storage system", Applied  Energy, 88, pp. 77{87 (2011).  12 Tan, H., Li, C., and Li, Y. Simulation research on  PCM freezing process to recover and store the cold  energy of cryogenic gas", International Journal of  Thermal Sciences, 50, pp. 2220{2227 (2011).  13 Gin, B., Farid, M., and Bansal, P. E_ect of door  opening and defrost cycle on a freezer with phase  change panels", Energy Conversion and Management,  51, pp. 2698{2706 (2010).  14 C_ akmak, G. and Y_ld_z, C. The drying kinetics of  seeded grape in solar dryer with PCM-based solar  integrated collector", Food and Bioproducts Processing,  89, pp. 103{108 (2011).  15 Buddhi, D., Sharma, S., and Sharma, A. Thermal  performance evaluation of a latent heat storage unit  for late evening cooking in a solar cooker having three  reectors", Energy Conversion and Management, 44,  pp. 809{817 (2003).  16 Li, Z. and Wu, Z.G. Analysis of HTFs, PCMs and  _ns e_ects on the thermal performance of shell-tube  thermal energy storage units", Solar Energy, 122, pp.  382{395 (2015).  17 Agyenim, F. and Hewitt, N. The development of a  _nned phase change material (PCM) storage system  to take advantage of o_-peak electricity tari_ for  improvement in cost of heat pump operation", Energy  and Buildings, 42, pp. 1552{1560 (2010).  M.M. Hosseini and A.B. Rahimi/Scientia Iranica, Transactions B: Mechanical Engineering 27 (2020) 239{251 251  18 Xiao, X., Zhang, P., and Li, M. Preparation and  thermal characterization of para_n/metal foam composite  phase change material", Applied Energy, 112,  pp. 1357{1366 (2013).  19 Ali Rabienataj, D., Farhadi, M., Jourabian, M., et al.  Natural convection melting of NEPCM in a cavity  with an obstacle using lattice Boltzmann method", Int.  Journal of Numerical Methods for Heat & Fluid Flow,  24, pp. 221{236 (2013).  20 Fan, L. and Khodadadi, L.J. An experimental investigation  of enhanced thermal conductivity and expedited  unidirectional freezing of cyclohexane-based  nanoparticle suspensions utilized as nano-enhanced  phase change materials (NePCM)", Int. Journal of  Thermal Sciences, 62, pp. 120{126 (2012).  21 Hosseini, M., Ranjbar, A., Rahimi, M., et al. Experimental  and numerical evaluation of longitudinally  _nned latent heat thermal storage systems", Energy  and Buildings, 99, pp. 263{272 (2015).  22 Al-Abidi, A.A., Mat, S., Sopian, K., et al. Experimental  study of melting and solidi_cation of PCM in  a triplex tube heat exchanger with _ns", Energy and  Buildings, 68, pp. 33{41 (2014).  23 Esapour, M., Hosseini, M., Ranjbar, A., et al. Phase  change in multi-tube heat exchangers", Renewable  Energy, 85, pp. 1017{1025 (2016).  24 Ho, C.R., Siao, Y.H., and Yan, W.M. Thermal energy  storage characteristics in an enclosure packed with  MEPCM particles: An experimental and numerical  study", Int. Journal of Heat and Mass Transfer, 73,  pp. 88{96 (2014).  25 Siao, Y.H., Yan, W.M., and Lai, C.M. Transient  characteristics of thermal energy storage in an enclosure  packed with MEPCM particles", Applied Thermal  Engineering, 88, pp. 47{53 (2015).  26 Ho, C., Liu, K., and Yan, W.M. Simulation on  melting processes in a vertical rectangular enclosure  with a free-moving ceiling", Int. Journal of Heat and  Mass Transfer, 83, pp. 222{228 (2015).  27 Darzi, A.A.R., Jourabian, M., and Farhadi, M. Melting  and solidi_cation of PCM enhanced by radial conductive  _ns and nanoparticles in cylindrical annulus",  Energy Conversion and Management, 118, pp. 253{  263 (2016).  28 Mahdi, J.M. and Nsofor, E.C. Melting enhancement  in triplex-tube latent thermal energy storage system  using nanoparticles-_ns combination", Int. Journal of  Heat and Mass Transfer, 109, pp. 417{427 (2017).  29 Al-Abidi, A.A., Mat, S., Sopian, K., et al. Internal  and external _n heat transfer enhancement technique  for latent heat thermal energy storage in triplex tube  heat exchangers", Applied Thermal Engineering, 53,  pp. 147{156 (2013).  30 Eslamnezhad, H. and Rahimi, A.B. Enhance heat  transfer for phase-change materials in triplex tube heat  exchanger with selected arrangements of _ns", Applied  Thermal Engineering, 113, pp. 813{821 (2017).  31 Brent, A., Voller, V., and Reid, K. Enthalpyporosity  technique for modeling convection-di_usion  phase change: application to the melting of a pure  metal", Numerical Heat Transfer, Part A Applications,  13, pp. 297{318 (1988).  32 Ye, W.B., Zhu, D.S., and Wang, N. Numerical  simulation on phase-change thermal storage/release in  a plate-_n unit", Applied Thermal Engineering, 31, pp.  3871{3884 (2011).  33 Ghaebi, H., Bahadori, M.N., and Saidi, M.H. Parametric  study of the pressure distribution in a con_ned  aquifer employed for seasonal thermal energy storage",  Scientia Iranica, 22(1), pp. 235{244 (2015).  34 Sa_khani, H., Ahmari, M., and Azadehfar, E. Numerical  study of conjugate heat transfer in laminar  and turbulent nanouid ow in double pipe heat  exchangers", Scientia Iranica, 23(5), pp. 2211{2219  (2016).  35 Patankar, S., Numerical Heat Transfer and Fluid Flow,  CRC press, London, U.K. (1980).