This paper describes a mathematical model for simulating the transient processes which occur in liquid flat-plate solar collectors. A discrete nodal model that represents the flat-plate solar collector's layers and the storage tank is employed. The model is based on solving a system of coupled differential equations which describe the energy conservation for the glass cover, air gap, absorber, fluid, insulation, and the storage tank. Inputs to the model include the time-varying liquid flow rate, incident solar radiation, and the ambient air temperature, as well as the volume of liquid in the storage tank and initial temperature of the system. The system of differential equations is solved iteratively using an implicit, finite-difference formulation executed with Matlab software. In order to verify the proposed method, an experiment was designed and conducted on different days with variable ambient conditions and flow rates. The comparison between the computed and measured results of the transient fluid temperature at the collector outlet shows good agreement. The proposed method is extremely general and flexible accounting for variable ambient conditions and flow rates and allowing for a geometrical and thermophysical description of all major components of the solar collector system, including the storage tank. The validated, general model is suitable to investigate the effectiveness of various components without the necessity of carrying out experimental work, and the flexible computational scheme is useful for transient simulations of energy systems.

References

References
1.
Goswami
,
D. Y.
,
Kreith
,
F.
, and
Kreider
,
J. F.
,
2000
,
Principles of Solar Engineering
,
2nd ed.
,
Taylor and Francis
,
Washington, DC
.
2.
Duffie
,
J. A.
, and
Beckmann
,
W. A.
,
2006
,
Solar Engineering of Thermal Processes
,
3rd ed.
,
Wiley Interscience
,
New York
.
3.
Klein
,
S.
,
Duffie
,
J.
, and
Beckman
,
W.
,
1974
, “
Transient Considerations of Flat-Plate Solar Collectors
,”
ASME J. Eng. Power
,
96A
(
2
), pp.
109
113
.10.1115/1.3445757
4.
Kamminga
,
W.
,
1985
, “
The Approximate Temperatures Within a Flat-Plate Solar Collector Under Transient Conditions
,”
Int. J. Heat Mass Transfer
,
28
(
2
), pp.
433
440
.10.1016/0017-9310(85)90076-6
5.
Hilmer
,
F.
,
Vajen
,
K.
,
Ratka
,
A.
,
Ackermann
,
H.
,
Fuhs
,
W.
, and
Melsheimer
,
O.
,
1999
, “
Numerical Solution and Validation of a Dynamic Model of Solar Collectors Working With Varying Fluid Flow Rate
,”
Sol. Energy
,
65
(
5
), pp.
305
321
.10.1016/S0038-092X(98)00142-X
6.
Zueva
,
G.
, and
Magiera
,
J.
,
2001
, “
Mathematical Model of Heat Transfer in Solar Collector and its Experimental Validation
,”
Theor. Found. Chem. Eng.
,
35
(
6
), pp.
604
608
.10.1023/A:1012945712472
7.
Cristofari
,
C.
,
Norton
,
G.
,
Poggi
,
P.
, and
Louche
,
A.
,
2002
, “
Modeling and Performance of a Copolymer Solar Water Heating Collector
,”
Sol. Energy
,
72
(
2
), pp.
99
112
.10.1016/S0038-092X(01)00092-5
8.
Cadafalch
,
J.
,
2009
, “
A Detailed Numerical Model for Flat-Plate Solar Thermal Devices
,”
Sol. Energy
,
83
(
12
), pp.
2157
2164
.10.1016/j.solener.2009.08.013
9.
Zima
,
W.
, and
Dziewa
,
P.
,
2010
, “
Mathematical Modeling of Heat Transfer in Liquid Flat-Plate Solar Collector Tubes
,”
Arch. Thermodyn.
,
31
(
2
), pp.
45
62
.10.2478/v10173-010-0008-7
10.
Zima
,
W.
, and
Dziewa
,
P.
,
2011
, “
Modeling of Liquid Flat-Plate Solar Collector Operation in Transient States
,”
Proc. IMechE Part A: J. Power Energy
,
225
(
1
), pp.
53
62
.10.1177/09576509JPE1044
11.
Rodríguez-Hidalgo
,
M. C.
,
Rodríguez-Aumente
,
P. A.
,
Lecuona
,
A.
,
Gutiérrez-Urueta
,
G. L.
, and
Ventas
,
R.
,
2011
, “
Flat Plate Thermal Solar Collector Efficiency: Transient Behavior Under Working Conditions. Part I: Model Description and Experimental Validation
,”
Appl. Therm. Eng.
,
31
(
14,15
), pp.
2394
2404
.10.1016/j.applthermaleng.2011.04.003
12.
Rodríguez-Hidalgo
,
M. C.
,
Rodríguez-Aumente
,
P. A.
,
Lecuona
,
A.
,
Gutiérrez-Urueta
,
G. L.
, and
Ventas
,
R.
,
2011
, “
Flat Plate Thermal Solar Collector Efficiency: Transient Behavior Under Working Conditions. Part II: Model Application and Design Contributions
,”
Appl. Therm. Eng.
,
31
(
14,15
), pp.
2385
2393
.10.1016/j.applthermaleng.2011.04.002
13.
Saleh
,
A. M.
,
2012
, “
Modeling of Flat-Plate Solar Collector Operation in Transient States
,” M.S. thesis, Purdue University, Fort Wayne, IN.
14.
Incropera
,
F. P.
,
DeWitt
,
D. P.
,
Bergman
,
T. L.
, and
Lavine
,
A. S.
,
2006
,
Fundamentals of Heat and Mass Transfer
,
6th ed.
,
Wiley Interscience
,
New York
.
15.
Saleh
,
A. M.
,
Mueller
, Jr.,
D. W.
, and
Abu-Mulaweh
,
H. I.
,
2013
, “
Flat-Plate Solar Collector in Transient Operation: Modeling and Measurements
,”
Proceeding of the ASME International Mechanical Engineering Congress and Exposition
,
ASME
Paper No. IMECE2013-62377.10.1115/IMECE2013-62377
16.
Silicon Solar, Inc.
,
2008
,
SunMaxx Flat Plate Solar Collectors
,
Innovative Solar Solutions, Silicon Solar, Inc.
,
New York
.
You do not currently have access to this content.