We report on the field testing of a 42 m-long full-scale solar receiver prototype installed on a 9 m-aperture solar trough concentrator. The solar receiver consists of a cylindrical cavity containing a tubular absorber with air as the heat transfer fluid (HTF). Experimental results are used to validate a heat transfer model based on Monte Carlo ray-tracing and finite-volume techniques. Performance predictions obtained with the validated model yield the following results for the receiver. At summer solstice solar noon, with HTF inlet temperature of 120 °C and HTF outlet temperature in the range 250–450 °C, the receiver efficiency ranges from 45% to 29% for a solar power input of 280 kW. One third of the solar radiation incident on the receiver is lost by spillage at the aperture and reflection inside the cavity. Other heat losses are due to natural convection (9.9–9.7% of solar power input) and re-radiation (6.1–17.6%) through the cavity aperture and by natural convection from the cavity insulation (5.6–9.1%). The energy penalty associated with the HTF pumping work represents 0.6–24.4% of the power generated.

References

1.
Bader
,
R.
,
Barbato
,
M.
, Pedretti., A., and
Steinfeld
,
A.
, 2010, “
An Air-Based Cavity Receiver for Solar Trough Concentrators
,”
ASME J. Sol. Energy Eng.
,
132
,
031017
.
2.
Bader
,
R.
,
Pedretti
,
A.
, and
Steinfeld
,
A.
, 2011, “
A 9m-Aperture Solar Parabolic Trough Concentrator Based on a Multilayer Polymer Mirror Membrane Mounted on a Concrete Structure
,”
ASME J. Sol. Energy Eng.
,
133
,
031016
.
3.
Collares-Pereira
,
M.
,
Gordon
,
J. M.
,
Rabl
,
A.
, and
Winston
,
R.
, 1991, “
High Concentration Two-Stage Optics for Parabolic Trough Solar Collectors With Tubular Absorber and Large Rim Angle
,”
Sol. Energy
,
47
,
457
466
.
4.
Almeco Tinox, Vega SP198.
5.
Patankar
,
S. V.
, 1980,
Numerical Heat Transfer and Fluid Flow
,
Hemisphere Publishing Corp
,
Washington/New York/London
.
6.
Gnielinski
,
V.
, 1976, “
New Equations for Heat and Mass-Transfer in Turbulent Pipe and Channel Flow
,”
Int. Chem. Eng.
,
16
, pp.
359
368
.
7.
Churchill
,
S. W.
, and
Chu
,
H. H. S.
, 1975, “
Correlating Equations for Laminar and Turbulent Free Convection From a Horizontal Cylinder
,”
Int. J. Heat Mass Transfer
,
18
, pp.
1049
1053
.
8.
Vargaftik
,
N. B.
, 1975,
Handbook of Physical Properties of Liquids and Gases
, 2nd ed.,
Hemisphere Publishing Corp.
,
Washington
.
9.
ANSYS CFX 12.1, 2009, ANSYS, Inc.
10.
Kuehn
,
T. H.
, and
Goldstein
,
R. J.
, 1978, “
An Experimental Study of Natural Convection Heat Transfer in Concentric and Eccentric Horizontal Cylindrical Annuli
,”
J. Heat Transfer
,
100
, pp.
635
640
.
11.
Design-Expert 7, Stat-Ease, Inc., Minneapolis, MN.
12.
Modest
,
M. F.
, 2003,
Radiative Heat Transfer
, 2nd ed.,
Academic Press
,
Amsterdam
.
13.
Berdahl
,
P.
, and
Martin
,
M.
, 1984, “
Emissivity of Clear Skies
,”
Sol. Energy
,
32
, pp.
663
664
.
14.
Reichardt
,
H.
, 1951, “
Die Grundlagen des turbulenten Waermeueberganges
,”
Arch. Ges. Waermetechn.
,
2
, pp.
129
142
.
15.
Munson
,
B. R.
,
Young
,
D. F.
, and
Okiishi
,
T. H.
, 1994,
Fundamentals of Fluid Mechanics
, 2nd ed.,
Wiley
,
New York
.
16.
Incropera
,
F. P.
, and
DeWitt
,
D. P.
, 2002,
Fundamentals of Heat and Mass Transfer
, 5th ed.,
Wiley
,
New York
.
17.
White
,
F. M.
, 2011,
Fluid Mechanics
, 7th ed.,
McGraw-Hill
,
New York
.
18.
Burkholder
,
F.
, and
Kutscher
,
C.
, 2009, “
Heat Loss Testing of Schott’s 2008 PTR70 Parabolic Trough Receiver
,” Technical Report, NREL/TP-550-45633.
19.
Hottel
,
H. C.
, 1976, “
A Simple Model for Estimating the Transmittance of Direct Solar Radiation Through Clear Atmospheres
,”
Sol. Energy
,
18
, pp.
129
134
.
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