Boundary design of stratified hot water heat stores is important not only to minimize the thermal losses to the ambient but also to preserve the thermodynamic quality of the stored energy. A new method of characterization, which equivalently accounts for both these concerns, is applied in this paper to investigate into the boundary design of large-scale hot water heat stores. A variety of concepts related to general design of the containments, namely, the effects of the thermal conductivity and thickness of the container wall, are numerically analyzed. The design insights provided by the analysis are in good agreement with the corresponding experimental results for small-scale hot water heat stores found in the literature. Different ways of insulation application, differential application of the external insulation, and insulation of the top walls are further investigated to obtain ideas for the efficient use of the insulation material. The new characterization scheme proves to be an efficient tool to rank the performance of different boundary designs during storing process of large-scale stratified hot water heat stores and to provide valuable design insights.
References
1.
Miller
, C. W.
, 1977, “Effect of Conducting Wall on a Stratified Fluid in a Cylinder
,” Heat Transfer and Thermal Control Systems, Progress in Astronautics and Aeronautics
, Vol. 60
, pp. 190
–208
.2.
Jaluria
, Y.
, and Gupta
, S. K.
, 1982, “Decay of Thermal Stratification in a Water Body for Solar Energy Storage
,” Sol. Energy
, 28
, pp. 137
–143
.3.
Hess
, C. F.
, and Miller
, C.W.
, 1982, “An Experimental and Numerical Study on the Effect of the Wall in a Thermocline-Type Cylindrical Enclosure-1: Experiments
,” Sol. Energy
, 28
, pp. 145
–153
.4.
Hess
, C. F.
, and Miller
, C. W.
, 1982, “An Experimental and Numerical Study on the Effect of the Wall in a Thermocline-Type Cylindrical Enclosure-1: Numerical Model
,” Sol. Energy
, 28
, pp. 153
–161
.5.
Murthy
, S. S.
, Nelson
, J. E. B.
, and Rao
, T. L. S.
, 1992, “Effect of Wall Conductivity on Thermal Stratification
,” Sol. Energy
, 49
, pp. 273
–277
.6.
Ghaddar
, N. K.
, and Al-Maarafie
, A. M.
, 1997, “Study of Charging of Stratified Storage Tank With Finite Wall Thickness
,” Int. J. Energy Res.
, 21
, pp. 411
–427
.7.
Nelson
, J. E. B.
, Balakrishnan
, A. R.
, and Murthy
, S. S.
, 1999, “Parametric Studies on Thermally Stratified Chilled Water Storage Systems
,” Appl. Therm. Eng.
, 19
, pp. 89
–115
.8.
Nelson
, J. E. B.
, Balakrishnan
, A. R.
, and Murthy
, S. S.
, 1999, “Experiments on Stratified Chilled Water Tanks
,” Int. J. Refrigeration
, 22
, pp. 216
–234
.9.
Eldighidy
, S. M.
, 1991, “Insulated Solar Storage Tanks
,” Sol. Energy
, 47
, pp. 253
–268
.10.
Shyu
, R. J.
, and Hsieh
, C. K.
, 1987, “Unsteady Natural Convection in Enclosure With Stratified Medium
,” ASME J. Sol. Energy Eng.
, 109
, pp. 127
–133
.11.
Dillon
, T. M.
, 1982, “Vertical Overturns: a Comparison of Thorpe and Ozmidov Length-Scales
,” JGE J. Geophys. Res.
, 87
, pp. 9601
–9613
.12.
Imberger
, J.
, 1985, “The Diurnal Mixed Layer
,” Limnol. Oceanogr.
, 30
(4
), pp. 737
–770
.13.
Imberger
, J.
, and Patterson
, J. C.
, 1990, “Physical Limnology
,” Adv. Appl. Mech.
, 27
, pp. 303
–475
.14.
Perera
, M. J. A. M.
, Fernando
, H. J. S.
, and Boyer
, D. L.
, 1994, “Turbulent Mixing at an Inversion Layer
,” J. Fluid Mech.
, 267
, pp. 275
–298
.15.
Amen
, R.
, and Maxworthy
, T.
, 1980, “The Gravitational Collapse of a Mixed Region Into a Linearly Stratified Fluid
,” J. Fluid Mech.
, 96
, pp. 65
–92
.16.
Rosen
, M. A.
, 1992, “Appropriate Thermodynamic Performance Measures for Closed Systems for Thermal Energy Storage
,” ASME J. Sol. Energy Eng.
, 114
, pp. 100
–105
.17.
Rosen
, M. A.
, 1999, “Second Law Analysis: Approaches and Implications
,” Int. J. Energy Res.
, 23
, pp. 415
–429
.18.
Rosen
, M. A.
, 2001, “The Exergy of Stratified Thermal Energy Storages
,” Sol. Energy
, 71
, pp. 173
–185
.19.
Rosen
, M. A.
, Hooper
, F. C.
, and Barbaris
, L. N.
, 1988, “Exergy Analysis for the Evaluation of the Performance of Closed Thermal Energy Storage Systems
,” ASME J. Sol. Energy Eng.
, 110
, pp. 255
–261
.20.
Rosen
, M. A.
, and Dincer
, I.
, 2003, “Exergy Methods for Assessing and Comparing Thermal Storage Systems
,” Int. J. Energy Res.
, 27
, pp. 415
–430
.21.
Rosen
, M. A.
, Tang
, R.
, and Dincer
, I.
, 2004, “Effect of Stratification on Energy and Exergy Capacities in Thermal Storage Systems
,” Int. J. Energy Res.
, 28
, pp. 177
–193
.22.
Panthalookaran
, V.
, Heidemann
, W.
, and Müller-Steinhagen
, H.
, 2007, “The Effects of Momentum Diffusers and Flow Guides on the Efficiency of Stratified Hot Water Seasonal Heat Stores
,” Int. J. Energy Res.
, 32
, pp. 911
–925
.23.
Panthalookaran
, V.
, 2008, “SEN Analysis of Stratified Hot Water Heat Stores With Respect to Axial Position and Number of Charging-Discharging Equipments
,” ASME 2008 9th Biennial Conference on Engineering Systems Design and Analysis
(ESDA 2008), Haifa
, Israel
, July 7–9, Paper No. ESDA2008-59079, pp. 1
–6
.24.
Panthalookaran
, V.
, Heidemann
, W.
, and Müller-Steinhagen
, H.
, 2007, “A New Method of Characterization for Stratified Thermal Energy Stores
,” Sol. Energy
, 81
, pp. 1043
–1054
.25.
Raab
, S.
, Mangold
, D.
, and Müller-Steinhagen
, H.
, 2005, “Validation of a Computer Model for Solar Assisted District Heating Systems With Seasonal Hot Water Heat Store
,” Sol. Energy
, 79
, pp. 531
–543
.26.
VDI Wärmeatlas, 2002, 9th ed., Springer, Berlin.
27.
Panthalookaran
V.
, 2007, “CFD-Assisted Characterization and Design of Hot Water Seasonal Heat Store
,” Doctoral thesis, University of Stuttgart, Shaker Verlag, Aachen.28.
Panthalookaran
, V
, El-Amin
, M. F.
, Heidemann
, W.
, and Müller-Steinhagen
, H.
, 2008, “Calibrated Models for Simulation of Stratified Hot Water Heat Stores
,” Int. J. Energy Res.
, 32
, pp. 661
–676
.29.
Panthalookaran
, V.
, Heidemann
, W.
, and Müller-Steinhagen
, H.
, 2006, “CFD-unterstütztes Design von Heisswasser-Langzeit-Wärmespeichern
,” OTTI, 16th Symposium Thermische Solarenergie—Mai
, 2006, Kloster Banz, Bad Staffelstein, Germany, pp. 383
–389
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