Effect of Buoyancy on the Perfomance of Solar Air Collectors with Different Structures
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In order to study the effect of buoyancy on the performance of solar air collector, the theoretical analysis and experimental tests of four solar air collectors with different structures under natural convection and mixed convection are carried out. The results show that the air temperature rise of the protrusion-corrugated plate air collector is the highest in the natural convection, which is 9.17 Chigher than that of the flat plate collector, and the air outlet velocity is 0.19 m/s, increasing by 16.88% than that of the flat plate collector. Observing the effects on the heat transfer performance of mixed convection, it can be found, in addition to the protrusion-corrugated plate air collector, the buoyancy plays a positive role on the other three solar air collectors in the upward flow, while the buoyancy plays a negative role on the other three solar air collectors in the downward flow, and the enhanced degree of the buoyancy to the corrugated plate air collector is the largest, while the enhancement degree of the flat plate collector is the least.
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- 3.Jackson, J.D. and Hall, W.B., Influences of buoyancy on heat transfer to fluids flowing in vertical tubes under turbulent conditions, in Proceedings of the Conference on Turbulent Forced Convection in Channels and Bundles, Hemisphere, 1979, pp. 613–640.Google Scholar
- 8.Wamotor, I.K., Database of fully developed channel flow, THTLAB Internal Report ILR-0201, Tokyo, Japan, 2003.Google Scholar
- 10.Xie Zhengrui, Yang Yanhua, and Gu Hanyang, Numerical analysis of turbulent mixed convection heat transfer in a rectangular channel, Nucl. Power Eng., 2009, vol. 30, no. 1, pp. 50–55.Google Scholar
- 11.Liu Minghou, Chen, T. L., and Chen Yiliang, Buoyancy effect on the flow and heat transfer characteristics of mixed convection, 2004, vol. 36, pp. 336–340.Google Scholar
- 14.Bazdidi-Tehrani, F. and Nezamabadi, M., Effect of Gr/Re on mixed convection and combined mixed convection-radiation heat transfer within a vertical channel with variable wall temperature, 2005, vol. 12, pp. 178–189.Google Scholar
- 23.Holman, J.P., Experimental Methods for Engineers, McGraw-Hill Series in Mechanical Engineering, New York: McGraw-Hill, 1994.Google Scholar
- 25.Esposito, A., Fluid Mechanics with Applications, Upper Saddle River, NJ: Prentice-Hall, 1998.Google Scholar