Abstract

This paper investigates the technical feasibility of innovative solar collectors. The proposed collectors have a phase change material (PCM) integrated into them as the storage mechanism. The PCM-integrated solar collector eliminates the need of conventional storage tanks, thus reducing cost and space. The present work uses a paraffin-graphite composite as the PCM to increase the conductivity of the PCM matrix. The paraffin’s melting point is around 89°C, which is appropriate for use in single-effect absorption systems. The mathematical model that describes the thermal process in the PCM is presented and differs from the analysis of conventional flat plate solar collectors making use of the lumped capacitance method which neglects spatial variations. The proposed model is calibrated favorably with a more detailed mathematical model that uses finite differences and considers temporal and spatial variations. Results for the collectors’ thermal performance are presented along with the effects of the composition of the PCM. The results for the PCM integrated collector proposed here are very encouraging. Therefore, there is an indication that conventional storage tanks may be replaced for the PCM integrated in the solar collector.

1.
Alva
,
L. H.
, and
González
,
J. E.
, 2002, “
Simulation of an Air-cooled Solar-assisted Absorption Air Conditioning System
,”
ASME J. Sol. Energy Eng.
0199-6231,
124
, pp.
276
282
.
2.
Bansal
,
N. K.
, and
Buddhi
,
D.
, 1992, “
Performance of a Cum Storage System
,”
Sol. Energy
0038-092X,
48
, pp.
185
194
.
3.
Rabin
,
Y.
,
Bar-Niv
,
I.
,
Korin
,
E.
, and
Mikic
,
B.
, 1995, “
Integrated Solar Collector Storage System Based on a Salt-hydrate Phase-change Material
,”
Sol. Energy
0038-092X,
55
, pp.
435
444
.
4.
Sokolov
,
M.
, and
Keizman
,
Y.
, 1991, “
Performance Indicators for Solar Pipes with Phase Change Storage
,”
Sol. Energy
0038-092X,
47
, pp.
339
346
.
5.
Py
,
X.
,
Olives
,
R.
, and
Mauran
,
S.
, 2001, “
Paraffin/Porous-Graphite-Matrix Composite as a High and Constant Power Thermal Storage Material
,”
Int. J. Heat Mass Transfer
0017-9310,
44
, pp.
2727
2737
.
6.
Hoogendoorn
,
C. J.
, and
Bart
,
G. C. J.
, 1992, “
Performance and Modeling of Latent Heat Stores
,”
Sol. Energy
0038-092X,
48
, pp.
53
58
.
7.
Alexiades
,
V.
, and
Solomon
,
A. D.
, 1993,
Mathematical Modeling of Melting and Freezing Processes
,
Hemisphere
,
Washington
.
8.
Duffie
,
J. A.
, and
Beckman
,
W. A.
, 1991,
Solar Engineering of Thermal Processes
,
Wiley
,
New York
.
9.
Incropera
,
F. P.
, and
DeWitt
,
D. P.
, 1996,
Fundamentals of Heat and Mass Transfer
,
Wiley
,
New York
.
You do not currently have access to this content.