Experimental Study of a Glazed Bi-Fluid (Water/Air) Solar Thermal Collector for Building Integration

Abstract

The present work proposes a study of different configurations of a bi-fluid thermal solar collector, where the two fluids (air and water) circulate in forced convection. The bi-fluid solar collectors are suitable for medium-temperature applications (as in the residential sector) and can be integrated into roofing homes. These solar collectors consist of a ribbed metal absorber and an air duct. Inside the ribs confined by a transparent cover, are arranged tubes of water. In this study, several configurations and geometric designs have been proposed and studied theoretically and experimentally in order to choose the most efficient of them from energy and technico-economic point of view. The theoretical analysis of this bi-fluid solar collector was performed based on a balance of heat transfers of the various elements constituting the solar device and taking into account the dynamic operating mode of the collector. Experimental work was also carried out in order of design and realization of a prototype of this type of solar collector in collaboration with the Solar Facilities Development Unit (UDES) in Tipaza (Algeria). Several on-site experimental tests have been made for different configurations of the bi-fluid solar collector. The configuration of the bi-fluid dual airflow solar collector showed the best energy performance in terms of thermal power and thermal efficiency (with an overall efficiency of 70%).