An analysis of the beam down optical experiment (BDOE) performance with full concentration is presented. The analysis is based on radiation flux distribution data taken on Mar. 21st, 2011 using an optical-thermal flux measurement system. A hypothetical thermal receiver design is used in conjunction with the experimental data to determine the optimal receiver aperture size as a function of receiver losses and flux distribution. The overall output of the plant is calculated for various operating temperatures and three different control strategies namely, constant mass flow of the heat transfer fluid (HTF), constant outlet fluid temperature and real-time optimal outlet fluid temperature. It was found that the optimal receiver aperture size (radius) of the receiver ranged between (1.06 and 1.71 m) depending on temperature. The optical efficiency of the BDOE ranged from 32% to 37% as a daily average (average over the ten sunshine hours). The daily average mean flux density ranged between 9.422 kW/m2 for the 1.71 m-receiver and 20.9 kW/m2 for the 1.06 m-receiver. Depending on the control parameters and assuming an open receiver with solar absorptivity of 0.95 and longwave emissivity of 0.10. The average receiver efficiency varied from 71% at 300 °C down to 68% at 600 °C. The overall daily average thermal efficiency of the plant was between 28% and 24%, respectively for the aforementioned temperatures. The peak of useful power collected in the HTF was around 105 kWth at 300 °C mean fluid temperature and 89 kWth at 600 °C.

References

References
1.
Kaltschmitt
,
M.
,
Streicher
,
W.
, and
Wiese
,
A.
,
2007
,
Renewable Energy: Technology, Economics and Environment
,
Springer
,
New York
.
2.
Charles
,
R. P.
,
Smith
,
J. L.
, and
Davis
,
K. W.
,
2003
, “
Assessment of Parabolic Trough and Power Tower Solar Technology Cost and Performance Forecasts
,” Sargent & Lundy LLC Consulting Group, National Renewable Energy Laboratory, Golden, CO.
3.
Tamaura
,
Y.
,
Utamura
,
M.
,
Kaneko
,
H.
,
Hasuike
,
H.
,
Domingo
,
M.
, and
Relloso
,
S.
,
2006
, “
A Novel Beam-Down System for Solar Power Generation With Multi-Ring Central Reflectors and Molten Salt Thermal Storage
,”
Proceedings of the 13th International Symposium on Concentrating Solar Power and Chemical Energy Technologies
, Seville, Spain.
4.
Hasuike
,
H.
,
Yuasa
,
M.
,
Wada
,
H.
,
Ezawa
,
K.
,
Oku
,
K.
,
Kawaguchi
,
T.
,
Mori
,
N.
,
Hamakawa
,
W.
,
Kaneko
,
H.
, and
Tamaura
,
Y.
,
2009
, “
Demonstration of Tokyo Tech Beam-Down Solar Concentration Power System in 100 kW Pilot Plant
,”
Proceedings of 15th International Symposium on Concentrated Solar Power and Chemical Energy Technologies
, Berlin, Germany.
5.
Mokhtar
,
M. M.
,
Meyers
,
S. A.
,
Rubalcaba
,
I.
,
Chiesa
,
M.
, and
Armstrong
,
P. R.
,
2012
, “
A Model for Improved Solar Irradiation Measurement at Low Flux
,”
Sol. Energy
,
86
(
3
), pp.
837
844
.10.1016/j.solener.2011.12.012
6.
Ulmer
,
S.
,
Reinalter
,
W.
,
Heller
,
P.
,
Lupfert
,
E.
, and
Martinez
,
D.
,
2002
, “
Beam Characterization and Improvement With a Flux Mapping System for Dish Concentrators
,”
ASME J. Sol. Energy Eng.
,
124
(
2
), pp.
182
188
.10.1115/1.1464881
7.
Ballestrín
,
J.
, and
Monterreal
,
R.
,
2004
, “
Hybrid Heat Flux Measurement System for Solar Central Receiver Evaluation
,”
Energy
,
29
(
5–6
), pp.
915
924
.10.1016/S0360-5442(03)00196-8
8.
Ulmer
,
S.
,
Lüpfert
,
E.
,
Pfänder
,
M.
, and
Buck
,
R.
,
2004
, “
Calibration Corrections of Solar Tower Flux Density Measurements
,”
Energy
,
29
(
5–6
), pp.
925
933
.10.1016/S0360-5442(03)00197-X
9.
McDonald
,
C. G.
,
1995
, “
Heat Loss From an Open Cavity
,” Sandia National Laboratories, Technical Report SAND95-2939.
10.
Clausing
,
A.
,
1981
, “
An Analysis of Convective Losses From Cavity Solar Central Receivers
,”
Sol. Energy
,
27
(
4
), pp.
295
300
.10.1016/0038-092X(81)90062-1
11.
Clausing
,
A. M.
,
1983
, “
Natural Convection Correlations for Vertical Surfaces Including Influences of Variable Properties
,”
ASME J. Heat Transfer
,
105
(
1
), pp.
138
143
.10.1115/1.3245532
12.
Clausing
,
A. M.
,
Waldvogel
,
J. M.
, and
Lister
,
L. D.
,
1987
, “
Natural Convection From Isothermal Cubical Cavities With a Variety of Side-Facing Apertures
,”
ASME J. Heat Transfer
,
109
(
2
), pp.
407
412
.10.1115/1.3248095
13.
Leibfried
,
U.
, and
Ortjohann
,
J.
,
1995
, “
Convective Heat Loss from Upward and Downward-Facing Cavity Solar Receivers: Measurements and Calculations
,”
ASME J. Sol. Energy Eng.
,
117
(
2
), pp.
75
84
.10.1115/1.2870873
14.
Taumoefolau
,
T.
,
Paitoonsurikarn
,
S.
,
Hughes
,
G.
, and
Lovegrove
,
K.
,
2004
, “
Experimental Investigation of Natural Convection Heat Loss From a Model Solar Concentrator Cavity Receiver
,”
ASME J. Sol. Energy Eng.
,
126
(
2
), pp.
801
807
.10.1115/1.1687403
15.
Prakash
,
M.
,
Kedare
,
S.
, and
Nayak
,
J.
,
2009
, “
Investigations on Heat Losses From a Solar Cavity Receiver
,”
Sol. Energy
,
83
(
2
), pp.
157
170
.10.1016/j.solener.2008.07.011
16.
Paitoonsurikarn
,
S.
,
Lovegrove
,
K.
,
Hughes
,
G.
, and
Pye
,
J.
,
2011
, “
Numerical Investigation of Natural Convection Loss From Cavity Receivers in Solar Dish Applications
,”
ASME J. Sol. Energy Eng.
,
133
(
2
), p.
021004
.10.1115/1.4003582
17.
Ma
,
R. Y.
,
1993
, “
Wind Effects on Convective Heat Loss From a Cavity Receiver for a Parabolic Concentrating Solar Collector
,” Sandia National Laboratories, Technical Report SAND92-7293.
18.
Hottel
,
H.
, and
Whillier
,
A.
,
1958
, “
Evaluation of Flat-Plate Solar Collector Performance
,”
Transactions of the Conference on Use of Solar Energy
,
E. F.
Carpenter
, ed., University of Arizona Press, Tucson, AZ, p.
74
.
19.
Duffie
,
J. A.
, and
Beckman
,
W. A.
,
2006
,
Solar Engineering of Thermal Processes
,
3rd ed.
,
Wiley
,
New York
.
20.
Mills
,
A. F.
,
1998
,
Heat Transfer
,
2nd ed.
,
Prentice Hall
,
Englewood Cliffs, NJ
.
21.
Winter
,
C.-J.
,
Sizmann
,
R. L.
, and
Vant-Hull
,
L. L.
,
1991
,
Solar Power Plants: Fundamentals, Technology, Systems, Economics
,
1st ed.
,
Springer
,
New York
.
22.
Mokhtar
,
M.
,
Rubalcaba
,
I.
,
Meyers
,
S.
,
Qadir
,
A.
,
Armstrong
,
P.
, and
Chiesa
,
M.
,
2010
, “
Heliostat Field Efficiency Test of Beam-Down CSP Pilot Plant—Experimental Results
,”
Proceedings of the 16th International Symposium on Concentrating Solar Power and Chemical Energy Technologies
, Perpignan, France.
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