Research Papers

Performance of a 100 kWth Concentrated Solar Beam-Down Optical Experiment

[+] Author and Article Information
Marwan Mokhtar

Research Engineer
Laboratory for Energy and Nano Science (LENS),
Department of Mechanical Engineering,
Masdar Institute of Science and Technology,
Abu Dhabi 54224, UAE
e-mail: marwan.mukhtar@gmail.com

Steven A. Meyers

Research Engineer
Laboratory for Energy and Nano Science (LENS),
Department of Mechanical Engineering,
Masdar Institute of Science and Technology,
Abu Dhabi 54224, UAE

Peter R. Armstrong

Associate Professor
Laboratory for Energy and Nano Science (LENS),
Department of Mechanical Engineering,
Masdar Institute of Science and Technology,
Abu Dhabi 54224, UAE
e-mail: parmstrong@masdar.ac.ae

Matteo Chiesa

Associate Professor
Laboratory for Energy and Nano Science (LENS),
Department of Mechanical Engineering,
Masdar Institute of Science and Technology,
Abu Dhabi 54224, UAE
e-mail: mchiesa@masdar.ac.ae

Contributed by the Solar Energy Division of ASME for publication in the JOURNAL OF SOLAR ENERGY ENGINEERING: INCLUDING WIND ENERGY AND BUILDING ENERGY CONSERVATION. Manuscript received April 7, 2014; final manuscript received April 10, 2014; published online May 15, 2014. Editor: Gilles Flamant.

J. Sol. Energy Eng 136(4), 041007 (May 15, 2014) (8 pages) Paper No: SOL-14-1113; doi: 10.1115/1.4027576 History: Received April 07, 2014; Revised April 10, 2014

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.

Copyright © 2014 by ASME
Your Session has timed out. Please sign back in to continue.


Kaltschmitt, M., Streicher, W., and Wiese, A., 2007, Renewable Energy: Technology, Economics and Environment, Springer, New York.
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.
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.
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.
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. [CrossRef]
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. [CrossRef]
Ballestrín, J., and Monterreal, R., 2004, “Hybrid Heat Flux Measurement System for Solar Central Receiver Evaluation,” Energy, 29(5–6), pp. 915–924. [CrossRef]
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. [CrossRef]
McDonald, C. G., 1995, “Heat Loss From an Open Cavity,” Sandia National Laboratories, Technical Report SAND95-2939.
Clausing, A., 1981, “An Analysis of Convective Losses From Cavity Solar Central Receivers,” Sol. Energy, 27(4), pp. 295–300. [CrossRef]
Clausing, A. M., 1983, “Natural Convection Correlations for Vertical Surfaces Including Influences of Variable Properties,” ASME J. Heat Transfer, 105(1), pp. 138–143. [CrossRef]
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. [CrossRef]
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. [CrossRef]
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. [CrossRef]
Prakash, M., Kedare, S., and Nayak, J., 2009, “Investigations on Heat Losses From a Solar Cavity Receiver,” Sol. Energy, 83(2), pp. 157–170. [CrossRef]
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. [CrossRef]
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.
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.
Duffie, J. A., and Beckman, W. A., 2006, Solar Engineering of Thermal Processes, 3rd ed., Wiley, New York.
Mills, A. F., 1998, Heat Transfer, 2nd ed., Prentice Hall, Englewood Cliffs, NJ.
Winter, C.-J., Sizmann, R. L., and Vant-Hull, L. L., 1991, Solar Power Plants: Fundamentals, Technology, Systems, Economics, 1st ed., Springer, New York.
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.


Grahic Jump Location
Fig. 1

BDOE overview. (a) Ganged-Type heliostat field and CR mirrors. CCD camera aperture is in the center of the CR taking images of the target below it. (b) Embedded within the target are water-cooled HFS at eight locations to calibrate the CCD camera images. (c) A typical luminance map taken by the CCD camera.

Grahic Jump Location
Fig. 2

BDOE heliostat field

Grahic Jump Location
Fig. 3

Day-average intercept factor (γ) as a function of receiver aperture radius (R)

Grahic Jump Location
Fig. 4

DNI during the test day

Grahic Jump Location
Fig. 5

Optical efficiency with optimal aperture

Grahic Jump Location
Fig. 6

Intercept factor variation during the test day for different receiver aperture sizes

Grahic Jump Location
Fig. 7

Luminance maps at different times of the day (local time UTC+4) shown in cd/m2. x and y axes are in pixels. Aberration is evident in early and late parts of the day which correspond to reduced intercept factor.

Grahic Jump Location
Fig. 8

Net power collected as a function of receiver radius. Convection and radiation losses are also shown as a function of receiver size, Tfo = 400 °C. Daily average is calculated over the ten sunshine hours of the test day.

Grahic Jump Location
Fig. 9

Receiver thermal efficiency. Average efficiency at 300 °C is 71%, at 400 °C is 73%, at 500 °C is 71% and at 600 °C is 68%.

Grahic Jump Location
Fig. 10

Overall efficiency of the BDOE. Overall efficiency at 300 °C is 28%, at 400 °C is 26%, at 500 °C is 25%, and at 600 °C is 24%.

Grahic Jump Location
Fig. 11

Thermal output of the receiver as function of time and outlet temperature

Grahic Jump Location
Fig. 12

Maximum mechanical power, which is indicative of the solar-to-electricity efficiency of the BDOE

Grahic Jump Location
Fig. 13

Comparison of control strategies. (a) Daily variation of maximum mechanical power, (b) mean fluid output temperature, (c) mass flow rate.



Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In