Performance of a Solar Cavity Collector System with the Implementations of Pebbles and Thermal Fluids

The fluid and water heating methods that use solar energy as a primary source have been accomplished successfully for more than a decade. Developments toward efficient water heating comprise solar concentrating collectors in addition to evacuative collectors. A new design which deals with an effective capture and utilization of energy is most needed for improving the efficiency of the overall system. One such arrangement toward the up-gradation of a flat plate collector [FPC] is the design and development of a solar cavity collector [SCC]. In this research paper, an experimental analysis of SCC with the usage of thermal storage material—pebbles and thermal fluids-has been presented. First, the receiver material is designed accordingly. A commercially available, standard-size copper pipe having a diameter of 0.0127 m has been taken into consideration for the receiver material. Then it is located at the center of the metal enclosure having a size of 50 mm. This setup composes a design of a single cavity and similarly, five such cavities have been fabricated and positioned inside the cavity collector. The total dimensions of the collector are 1.25 m × 0.85 m × 0.05 m respectively. For the better heat transfer enhancement of the SCC, pebbles are used as a heat storage sensible heat material. In order to achieve more heat transfer enhancement, Therminol-55, one type of heat transfer fluid [HTF] has been used between the outside of the cavity and the working fluid.