Effect of Periodic Variation of Sol-air Temperature on the Performance of Integrated Solar Collector Storage System

Nawaf H. Saeid, Tan Jun Wong

.

DOI: 10.4236/eng.2010.210106                

Abstract

Parametric study is carried out in the present article to investigate the unsteady performance of solar energy gain and heat retention of two different integrated-collector-storage systems. The systems are the conventional rectangular-shaped storage tank and the modified tank shaped as rectangular cuboid with one semi -circular top. The two systems have the same absorber surface area and volume for water. The heat and fluid flow is assumed to be unsteady, two-dimensional, laminar and incompressible. The performances of the two systems are evaluated based on the maximum temperature in the system during daytime heating period and nighttime cooling period. For comprehensive study, 24 hours simulations for 3 cases with different wall boundary condition impose on the absorber plate are investigated. The simulation results show that the modified system has better heat retain than the conventional system. Periodic variations of both systems are investigated, and it is found that both systems show consistent results on different days. The modified system is able to store most of the thermal energy in the semi-circular top region with higher temperature than that of the conventional system.

Keywords

Heat Transfer, Integrated Solar Collector Storage, Buoyancy Driven Flow, Numerical Study

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Solarthermal.com (http://solarthermal.com).
[2]	S. A. Kalogirou, “Solar Thermal Collectors and Applications,” Progress in Energy and Combustion Science, Vol. 30, No. 3, 2004, pp. 231-295.
[3]	C. Garnier, J. Currie and T. Muneer, “Integrated Collector Storage Solar Water Heater: Temperature Stratification,” Applied Energy, Vol. 86, No. 9, 2009, pp. 1465-1469.
[4]	S. A. Kalogirou, “Design, Construction, Performance Evaluation and Economic Analysis of an Integrated Collector Storage System,” Renew Energy, Vol. 12, No. 2, 1997, pp. 179-192.
[5]	A. Sridhar and K. S. Reddy, “Transient Analysis of Modified Cuboid Solar Integrated Collector-Storage System,” Applied Thermal Engineering, Vol. 27, No. 2-3, 2007, pp. 330-346.
[6]	S. Ostrach, “Natural Convection in Enclosures,” ASME Journal of Heat Transfer, Vol. 110, No. 4b, 1988, pp. 1175-1190.
[7]	D. Poulikakos, “Natural Convection in a Confined Fluid-Filled Space Driven by a Single Vertical Wall with Warm and Cold Regions,” ASME Journal of Heat Transfer, Vol. 107, No. 4, 1985, pp. 867-876.
[8]	N. H. Saeid, “Computational Aspects for Natural Convection in a Cavity Using Vorticity-Stream Function Method,” In: G. R. Liu et al., Ed., Computational Methods, Springer, 2006, pp. 255-261.
[9]	N. H. Saeid and Y. Yaacob, “Natural Convection in a Square Cavity with Spatial Sidewall Temperature Variation,” Numerical Heat Transfer, Part A, Vol. 49, No. 7, 2006, pp. 683-697.
[10]	N. H. Saeid, “Conjugate Natural Convection in a Porous Enclosure: Effect of Conduction in One of the Vertical Walls,” International Journal of Thermal Sciences, Vol. 46, No. 6, 2007, pp. 531-539.
[11]	Fluent 6.3 User’s Guide, Fluent Inc. http://www.fluentusers.com
[12]	H. K. Versteeg and W. Malalasekera, “An introduction to Computational Fluid Dynamics,” Longman, New York, 1995.
[13]	S. V. Patankar, “Numerical Heat Transfer and Fluid Flow,” McGraw-Hill, New York, 1980.
[14]	R. I. Issa, “Solution of the Implicitly Discretised Fluid Flow Equations by Operator Splitting,” Journal of Computational Physics, Vol. 62, No. 1, 1986, pp. 40-65.