Experimental and Numerical Analysis of a PCM-Supported ...

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[109] Mehling H., Hiebler S. and Ziegler F. (2000). Latent heat storage using a PCM graphite composite material. Proc. of Terrastock 8 th international conference on Thermal Energy Storage, 28 August – 1 September 2000, Vol. 1: 375-380. [110] Stritih U. and Novak, P. (2000). Heat transfer enhancement of phase change process. Proc. of Terrastock 8 th international conference on Thermal Energy Storage, 28 August – 1 September 2000, Vol. 1: 333-338. [111] U.S. Department of energy, Energy Efficiency and Renewable Energy, Energy Savers. Phase change materials for solar heat storage. National Technical Information System (NTIS), info@ntis.gov. [112] Bajnoczy G., Palffy E. G., Prepostffy E. and Zold A. (1999). Heat storage by two grade phase change material", Periodica Polytechnica Ser Chem. Eng., 43(2): 137-147. [113] Farid M. and Yacoub K. (1989). Performance of direct contact latent heat storage unit. Solar Energy 43(4): 237 –51. [114] Sokolov M. and Keizman Y. (1991). Performance indicators for solar pipes with phase change energy storage. Solar Energy 47(5): 339- 346. [115] Trelles J.P. and Duffy J.P. (2003). Numerical simulation of porous latent heat thermal energy storage for thermoelectric cooling. Applied Thermal Engineering 23: 1647 - 1664. [116] Watanbe T., Kikuchi H. and Kanzawa A. (1993). Enhancement of charging and discharging rates in a latent heat storage system by use of PCM with different melting temperatures. Heat Recovery Systems CHP 13 (1): 57- 66. [117] Galloway T.R. and Sage B.H. (1970). A Model of the mechanism of transport in packed, distended and fluidized beds. Chemical Engineering Science 25: 495. [118] Kuwahara F., Shirota M. and Nakayama A. (2001). A numerical study of interfacial convective heat transfer coefficient in two-energy equation model for convection in porous media. International Journal of Heat and Mass Transfer 44: 1153-1159. [119] Anathanarayanan V., Sahai Y., Mobley C.E. and Rapp R.A. (1987). Modelling of fixed bed heat storage units utilizing phase change materials. Metallurgical and Materials Transactions B. 18B: 339-346. [120] Saito M.B. and De Lemos M.J. (2005). Interfacial heat transfer coefficient for non-equilibrium convective transport in porous media. International Communications in Heat and Mass Transfer 32: 666–676. [121] Singh R., Saini R.P. and Saini J.S. (2006). Nusselt number and friction factor correlations for packed bed solar energy storage system having large sized elements of different shapes. Solar Energy 80: 760-771. [122] Standish, N. and Drinkwater, J.B. (1970). The effect of particle shape on flooding rates in packed columns. Chemical Engineering Science 25: 1619- 1621. [123] Gauvin W.H. and Katta S. (1973). Momentum transfer through packed beds of various particles in the turbulent flow regime", AIChE Journal 19(4): 775-783. 187
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Technische Universität München In
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It is my pleasure to thank Prof. Th
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Contents List of figures ..........
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5.3 Functional description ........
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List of Figures Figure 1.1: Cost br
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78cm; Top: Evaporator, Bottom: Cond
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xii
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m Mass flow rate; [kg.s -1 ] m eva
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ed c coll cond cw d d e or eff evap
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1 Introduction The first part of th
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summarized in figure (1.2). Thermal
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1.3.2 Selection criteria of desalin
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of energy storage or hybridization
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Desalination development focuses on
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Introduction of the indirect type s
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2 Literature Survey 2.1 Introductio
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There is actually a commercial prod
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Q m H c ( T T1) c ( T 2 T ) (2.2)
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(solid-liquid) have a storage densi
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(iii) a sharp melting temperature.
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melt and freeze without segregation
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However, the stored heat is less va
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parameters on the heat transfer and
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categories. The first category is b
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to 550 kWh/m 3 of distilled water a
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The enthalpy and humidity of the sa
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Air mass flow rate [kg/h] GOR [-] 1
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On the other hand, the efficiency o
Page 58 and 59:
2.8.4.2 Effect of air to water mass
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distillate rate. The system was not
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were; EnviPac Gr.1, 32 mm, and VFF
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Figure 2.15: Height versus air temp
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The performance of the condenser is
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Klausner and Mei [136] described a
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The impact of the collector cost ca
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exchanger and energy storage in one
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3 Scope of the Study This chapter p
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packing where it gets in direct con
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In fact there is a tradeoff between
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The energy flow between all and eac
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4 Theoretical Analysis and Modeling
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The two-energy equation models whic
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solid-liquid phase change inside th
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assumed by conduction in both axial
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the air pressure drop ∆P per unit
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evaporation rate per unit volume of
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where β t , β c , ρ ref , c ref
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the viscous transport and introduce
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liquid and solid phases, respective
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4.2.3.3 Liquid and gas hold-ups Liq
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Several models and approaches for m
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where G=ρU d /ε g is the pore mas
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k k eff s 1 3 2 (4.55) This cor
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uncertainties associated with the f
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1 2 (4.62) d1 capp c2 c1 c2 1
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[58] evaluated the cooling tower ai
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1 exp NTU 1 C r, cond cond (4
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A HE QHE U T HE LM (4.81) Where Q
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c M f b (4.86) M b S S f where r
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that form the study logical foundat
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5 Experimental Analysis This chapte
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5.2 Measuring Techniques K-type the
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The product condensed water was mea
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operating limits. In light of the l
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In the last two cases, the inlet ho
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performance and its threshold value
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It could be interpreted that this p
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Evaporator Condenser Figure 5.8: Av
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within the inaccuracy margins. The
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The last two cases of boundary cond
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natural air flow in the system. In
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6 Model Implementation and Validati
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x t u x u 0 0 , (6.5) and for a s
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Next time step validation were the
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The evaporator and condenser both w
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Figure 6.2: Evolution of inlet and
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Figure 6.4: Evolution of inlet and
Page 156 and 157: temperature is at its maximum level
Page 158 and 159: Bottom Top Figure 6.7: Evolution of
Page 160 and 161: 7 Parameters Analysis of the Evapor
Page 162 and 163: Figure 7.1: Effect of packing size
Page 164 and 165: e 0.45 kPa under natural convection
Page 166 and 167: aspect ratio under constant bed vol
Page 168 and 169: Figure 7.7: Effect of inlet hot wat
Page 170 and 171: well as the time required to reach
Page 172 and 173: Figure 7.10: Effect of packing medi
Page 174 and 175: 40°C respectively. This gives flex
Page 176 and 177: the condensate rate, productivity f
Page 178 and 179: esult, rather than PCM media which
Page 180 and 181: Figure 7.18: Effect of PCM thermal
Page 182 and 183: 8 Optimization of HDH plant In this
Page 184 and 185: The MATLAB model describes how the
Page 186 and 187: less steep than that of the distill
Page 188 and 189: 8.3.4 Effect of hot water flow rate
Page 190 and 191: storage materials and thus it can h
Page 192 and 193: for latent heat storage would be ob
Page 194 and 195: When T m becomes sufficiently highe
Page 196 and 197: 9 Summary and conclusions 9.1 Summa
Page 198 and 199: productivities at any cooling water
Page 200 and 201: [13] Vafai K., Sozen M. An investig
Page 202 and 203: [48] Crone S., Bergins C., and Stra
Page 204 and 205: [79] Tiwari G.N. and Yadav Y.P. (78
Page 208 and 209: [139] Belessiotis V, Delyannis E (2
Page 210 and 211: Appendices Appendix A A1. PCM Therm
Page 212 and 213: A3. Constants and Thermo-physical p
Page 214 and 215: From the above correlation, the con
Page 216 and 217: The Ergun analogy factor J h repres
Page 218 and 219: Equation (C.7) represents an overal
Page 220 and 221: Appendix D D1. Cooling tower theory
Page 222 and 223: A m w = the plan or cross sectiona
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