OJFD  Vol.5 No.1 , March 2015
Numerical Investigation of Effective Heat Conductivity of Fluid in Charging Process of Thermal Storage Tank
Abstract: This paper presents a numerical case study of heat transfer mechanisms during the charging process of a stratified thermal storage tank applied in a specific adsorption heat pump cycle. The effective thermal conductivity of the heat transfer fluid during the charging process is analyzed through CFD simulations using Unsteady Reynolds-averaged Navier-Stokes equations (URANS). The aim of the study is to provide an equivalent thermal conductivity for a one-dimensional storage tank model to be used in a system simulation of the complete adsorption heat pump cycle. The influence of the turbulent mixing and also the advection effect due to fluid bulk motion are investigated. The results show that in the case considered here, the turbulence effect on the effective thermal conductivity is more considerable than the advection effect.
Cite this paper: Taheri, H. , Schmidt, F. and Gabi, M. (2015) Numerical Investigation of Effective Heat Conductivity of Fluid in Charging Process of Thermal Storage Tank. Open Journal of Fluid Dynamics, 5, 39-50. doi: 10.4236/ojfd.2015.51006.

[1]   Schwamberger, V., Joshi, C. and Schmidt, F.P. (2011) Second Law Analysis of a Novel Cycle Concept for Adsorption Heat Pumps. International Sorption Heat Pump Conference (ISHPC11), Padua, 28-29 April 2011, 991-998.

[2]   Eicker, U. and Pietruschka, D. (2009) Design and Performance of Solar Powered Absorption Cooling Systems in Office Buildings. Energy and Buildings, 41, 81-91.

[3]   Schmidt, F. (2012) Entwicklungspotenzial thermisch angetriebener Warmepumpen. Jahrestagung KIT-Zentrum Energie.

[4]   Zurigat, Y.H., Liche, P.R. and Ghajar, A.J. (1991) Influence of Inlet Geometry on Mixing in Thermocline Thermal Energy Storage. International Journal of Heat and Mass Transfer, 34, 115-125.

[5]   Alizadeh, S. (1999) An Experimental and Numerical Study of Thermal Stratification in a Horizontal Cylindrical Solar Storage Tank. Solar Energy, 66, 409-421.

[6]   Nelson, J.E.B., Balakrishnan, A.R. and Murthy, S.S. (1998) Transient Analysis of Energy Storage in a Thermally Stratified Water Tank. International Journal of Energy Research, 22, 867-883.<867::AID-ER410>3.0.CO;2-L

[7]   Bouhdjar, A. and Harhad, A. (2002) Numerical Analysis of Transient Mixed Convection Flow in Storage Tank: Influence of Fluid Properties and Aspect Ratios on Stratification. Renewable Energy, 25, 555-567.

[8]   Shah, L.J. and Furbo, S. (2003) Entrance Effects in Solar Storage Tanks. Solar Energy, 75, 337-348.

[9]   Cònsul, R., et al. (2004) Virtual Prototyping of Storage Tanks by Means of Three-Dimensional CFD and Heat Transfer Numerical Simulations. Solar Energy, 77, 179-191.

[10]   Shah, L.J., Andersen, E. and Furbo, S. (2005) Theoretical and Experimental Investigations of Inlet Stratifiers for Solar Storage Tanks. Applied Thermal Engineering, 25, 2086-2099.

[11]   Altuntop, N., et al. (2005) Effect of Obstacles on Thermal Stratification in Hot Water Storage Tanks. Applied Thermal Engineering, 25, 2285-2298.

[12]   Andersen, E., et al. (2008) Investigations on Stratification Devices for Hot Water Heat Stores. International Journal of Energy Research, 32, 255-263.

[13]   (2010) Firma Sailer, Sailer Einschichtvorrichtung.

[14]   Kaminski, E., Tait, S. and Carazzo, G. (2005) Turbulent Entrainment in Jets with Arbitrary Buoyancy. Journal of Fluid Mechanics, 526, 361-376.

[15]   (2004) Produktinformationen zu Marlotherm SH, Marlotherm LH (Datenblatt). Firma Sasol.

[16]   (2011) Ansys Fluent 14.0 User’s Guide. Ansys, Inc.

[17]   Steinert, P., Goppert, S. and Platzer, B. (2013) Transient Calculation of Charge and Discharge Cycles in Thermally Stratified Energy Storages. Solar Energy, 97, 505-516.