A parabolic trough solar receiver, also called the heat collection element (HCE), is the key component to reduce the heat loss and improve the optical-thermal efficiency in parabolic trough solar system. Testing and operating results show that expect for the major heat loss through glass envelope, heat transfer through the receiver’s end components, metal bellow, Kovar and support bracket, have a larger heat flux that is able to affect the accuracy of laboratorial thermal test and reduce the thermal efficiency in the actual operation. In this paper, the structures and heat transfer mechanisms of inner-bellow and outer-bellow end structures are analyzed at first. Then, 3-D models are performed to simulate the heat losses process by CFD software. In order to investigate heat loss influence in real operating environment, the end heat losses are simulated under different vacuum levels and wind speeds. Modelled results show receiver’s end should be covered by heat insulator during the laboratorial test to avoid end influence, except for the inner-bellow receiver without flange. Because of a vacuum annulus, either outer or inner bellow structure increases a small heat loss while the flange or support bracket lead to a large heat loss. Simulation also shows all the end components are sensitive to the changes of vacuum level and wind speed, which should be completely covered in the solar field.
Keywords. parabolic trough solar; solar receiver; end heat loss; bellow design; heat loss simulation
References
D. Kearney, H. Price, 2005. Recent Advances in Parabolic Trough Solar Power Plant Technology. Advances in Solar Energy, Volume 16, ASES 2005.
J. Wang, Y.M. Zhang, 2007. Development and study on vacuum absorber tubes. Proceedings of ISES solar world congress 2007, pp. 1813-1817, 2007.
X.Y. Huang et al., 2010. Testing and Analysis on the Thermal Properties of a New High Temperature Parabolic Trough Receiver. Proceedings of ASME International Colloquium on Environmentally Preferred Advanced Power Generation, February 9- 11, 2010, Costa Mesa, CA, U.S.
G.J. Gong et al., 2010. Modelling and Test results on Heat Loss of Vacuum Absorber Tuber in Parabolic Trough Solar Plant. Proceedings of ASME International Colloquium on Environmentally Preferred Advanced Power Generation, February 9- 11, 2010, Costa Mesa, CA, U.S.
F. Burkholder, C. Kutscher, 2008. Heat Loss Testing of Solel’s UVAC3 Parabolic Trough Receiver. Technical Report NREL/TP-550-42394, January 2008.
F. Burkholder, C. Kutscher, 2009. Heat Loss Testing of Schott’s PTR70 Parabolic Trough Receiver. Technical Report NREL/TP-550-45633, May 2009.
S.D. ODEH, G.L. MORRISON, M. BEHNIA, 1998. Modeling of parabolic trough direct steam generation solar collectors. Solar Energy Vol. 62, No. 6, pp. 395-406, 1998.
H. Price, R. Forristall, T. Wendelin, T. Moss et al, 2006. Field survey of parabolic trough receiver thermal performance. conference paper NREL/CP-550-39459, April 2006.
R. Forristall, 2003. Heat Transfer Analysis and Modeling of a Parabolic Trough Solar Receiver Implemented in Engineering Equation Solver. Golden, Colorado: National Renewable Energy Laboratory, 2003, 5-16.
M. Martin, P, Berdahl, 1984. Characteristics of the infrared sky radiation in the United States. Solar Energy, 33, pp.321–336, 1984.
F.P. Incropera, D.P. Dewitt, 1990. Introduction to heat transfer, 2nd ed. New York: Wiley; 1990.
L. Moens, D. Blake, 2008. Mechanism of hydrogen formation in solar parabolic trough receivers. Technical Report NREL/TP-510-42468, February 2008.
How to cite this article
Huang, X., Gong, G., Wang, J., Hao, M. and Bao, Z. (2010). 'Heat Loss Analysis and Modelling on End Structures of the Parabolic Trough Solar Receivers'. SET Proceedings, 9, pp. 1-9. https://doi.org/10.65582/set.2010.080
