In this work, the thermal performance of a conventional collector is improved by inserting porous substrates at the inner walls of the collector tubes. The porous substrates improve the convective heat transfer coefficient between the tube wall and the fluid. This improvement is investigated numerically and its effects on the efficiency and the useful gain of the collector are evaluated. It is found that inserting the porous substrate may raise the collector efficiency considerably, especially at high values of the overall heat loss coefficient.
Issue Section:
Research Papers
1.
Al-Nimr, M., and Alkam, M., 1997,“Unsteady Non-Darcian Forced Convection Analysis in an Annulus Partially Filled with a Porous Material,” accepted for publication in ASME Journal of Heat Transfer.
2.
Beikircher
T.
Spirkl
W.
1996
, “Analysis of Gas Heat Conduction in Evacuted Tube Solar Collectors
,” ASME JOURNAL OF SOLAR ENERGY ENGINEERING
, Vol. 118
, pp. 157
–161
.R@Bodoia, J. R., and Osterle, J. F., 1961, “Finite-Difference Analysis of Plane Poiseuille and Couette Flow Developments,” Apll. Sci. Res. A10, pp. 265–276.3.
Cheung, A., Chiang, C., and Chen, M., 1979, “Heat Transfer in Porous Medium Flat Plate Solar Collector,” Proc. Multi-Phases Flow and Heat Transfer Symp. Workshop, Miami Beach, Vol. 5, pp. 2407–2411.
4.
Chikh
S.
Boumedian
A.
Bouhadef
K.
Lauriat
G.
1995
, “Non-Darcian Forced Convection Analysis in an Annular Partially Filled with a Porous Material
,” Numerical Heat Transfer A
, Vol. 28
, pp. 707
–722
.5.
Duffie, J., and Beckman, W., 1991, Solar Engineering of Thermal Processes, 2nd edition, John Wiley and Sons, Chap. 5 and 6.
6.
Issa, M., Kodah, Z., and Al-Nimr, M. A., 1990, “Further Development of a V-Trough Solar Concentrator,” Int. J. Solar Energy, No. 8, pp. 81–96.
7.
Jang
J. Y.
Chen
J. L.
1992
, “Forced Convection in a Parallel Plate Channel Partially Filled with a High Porosity Medium
,” Int. Comm. Heat and Mass Transfer
, Vol. 19
, pp. 263
–273
.8.
Kleinstreuer
C.
Chiang
H.
1990
, “Analysis of a Porous-Medium Solar Collector
,” Heat Transfer Engineering
, Vol. 11
, No. 2
, pp. 45
–55
.9.
Kleinstreuer, C., and Chin, T., 1984, “Performance Evaluation of a Porous Medium Flat Plate Solr Collector,” ASME and AIChE Heat Transfer Conference, Niagara Falls, AIChE Symp. Ser., Vol. 80, pp. 236–241.
10.
Kribus
A.
Ries
H.
Spirkl
W.
1996
, “Inherent Limitations of Volumetric Solar Receivers
,” ASME JOURNAL OF SOLAR ENERGY ENGINEERING
, Vol. 118
, pp. 151
–155
.11.
Lunde, P. J., 1980, Solar Thermal Engineering, John Wiley, New York, p. 206.
12.
McVeigh, J. C., Sun Power, 2nd ed., 1983, Pergamon Press, Oxford.
13.
Poulikakos
D.
Kazmierczak
M.
1987
, “Forced Convection in a Duct PartiallyFilled with a Porous Material
,” ASME JOURNAL OF HEAT TRANSFER
, Vol. 109
, pp. 653
–662
.14.
Rudraiah
N.
1985
, “Forced Convection in a Parallel Plate Channel Partially Filled with a Porous Material
,” ASME JOURNAL OF HEAT TRANSFER
, Vol. 107
, pp. 322
–331
.15.
Smirnov
S. V.
Moyseenko
V. V.
1995
, “The Effect of Heat Radiation of a Solar Collector’s Absorbing Surface Elements on its Efficiency
,” Applied Solar Energy
, Vol. 31
, No. 6
, pp. 72
–78
.16.
Vafai
K.
Alkire
R. L.
Tien
C. L.
1985
, “An Experimental Investigation of Heat Transfer in Variable Porosity Media
,” Journal Heat Transfer
, Vol. 107
, p. 642
642
.17.
Vafai
K.
Kim
S. J.
1995
, “On the Limitations of the Brinkman-Forchheimer-Extended Darcy Equation
, Int J. Heat and Fluid Flow
, Vol. 16
, pp. 1l–l5
1l–l5
.18.
Vafai
K.
Kim
S. J.
1990
, “Fluid Mechanics of the Interface Region Between a Porous Medium and a Fluid Layer-An Exact Solution
,” Int. J. Heat and Fluid Flow
, Vol. 11
, pp. 254
–256
.19.
Vafai
K.
Thiyagaraja
R.
1987
, “Analysis of Flow and Heat Transfer at the Interface Region of a Porous Medium
,” Int. J. Heat and Mass Transfer
, Vol. 30
, pp. 1391
–1405
.
This content is only available via PDF.
Copyright © 1999
by The American Society of Mechanical Engineers
You do not currently have access to this content.