Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.
A receiver is a central component of the parabolic trough collector system. Its design and state greatly affects performance of the entire collector system. In this paper a three dimensional numerical model of a receiver with an externally longitudinally finned absorber tube was developed to study the effect of fin dimensions on heat transfer and fluid flow performance characteristics. Results show that external longitudinal fins improve the performance of the receiver. Results further show that collector efficiency and useful heat gain will increase as the fin thickness and height increase and so do heat losses, glass temperature and maximum absorber temperature. A 6% increase in efficiency and a pressure drop of 370.65Pa/m are obtained for a finned absorber tube with lower dimensions 1.0 cm x 0.2 cm when compared to a non-finned tube larger in diameter by 1 cm. An increase in efficiency of 8% is obtained when the same finned absorber tube is compared with a non-finned tube of the same size.