Experimental and numerical performance analyses of a Dish-Stirling cavity receiver: Geometry and operating temperature studies. (August 2018)

• Record Type: Journal Article
• Authors: Garrido, Jorge; Aichmayer, Lukas; Abou-Taouk, Abdallah; Laumert, Björn
• Is Part Of: Solar energy. Volume 170(2018)
• Page Start: 913
• Page End: 923
• Publication Date: 2018-08
• Subjects: Solar simulator -- Experimental measurements -- System modelling -- Receiver design; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2018.06.031
• Languages: English
• ISSNs: 0038-092X

Abstract

Highlights: Parametric experimental study varying the cavity geometry and working temperature. Large set of experimental data collected capturing detailed performance parameters. System simulations validated against multiple parameters and operating conditions. Cavity receiver designed to maximize the total electric generation. Peak receiver temperatures obtained from thermocouple measurements. Abstract: Higher performance cavity receivers are needed to increase the competitiveness of solar power plants. However, the design process needs to be improved with more relevant experimental and numerical analyses. Thereby, the performance of four different Dish-Stirling cavities is investigated experimentally analyzing the influence of the cavity aperture diameter and shape at various operating temperatures. Temperatures inside the cavity receiver were collected together with the electrical power produced by the engine-generator. Then, a thermal system simulation was modelled and a comprehensive multi-parameter and multi-operation validation was performed. To improve this validation, the temperature distribution across the receiver tubes was analyzed in order to relate temperatures on the irradiated region with the non-irradiated one, where thermocouples can measure. The simulations were later used to obtain cavity receiver efficiencies, temperatures and loss breakdowns. The results show that the cavity receiver must be studied in optimization processes in conjunction with the other system components. Moreover, the reverse-conical cavity was found to be more efficient than a nearly cylindrical shape. Regarding the cavity receiver thermal losses, radiation and natural convection present similar contributions in the system under study. Finally, it was found that thermocouples installed on a non-irradiated region can be used to obtain peak receiver temperatures if the measurements are rectified by a correction value proportional to the DNI.