Eventos Anais de eventos
ENCIT 2016
16th Brazilian Congress of Thermal Sciences and Engineering
EXPERIMENTAL EVALUATION OF AN ENHANCED TRANSPARENT INSULATION SYSTEM ON A GLASS-PLATE CAVITY
Submission Author:
Rafael Paiva Garcia , SP
Co-Authors:
Vicente Luiz Scalon, Alcides Padilha
Presenter: Rafael Paiva Garcia
doi://10.26678/ABCM.ENCIT2016.CIT2016-0302
Abstract
Flat plate solar collectors for use in domestic hot water systems have their efficiency highly compromised by the heat losses on top. This region has the insulation com- plicated as it depends on high transparency levels to let solar radiation reach the absorber surface of the collector. Heat losses by this surface typically represent 60% more than global ones. Several alternatives have been analyzed to attempt to work around this issue highlighting the use of transparent insulation materials or double glazing. However, these techniques have not shown feasibility to allow their commer- cial application. This work evaluates the use of an insulation system that has little effect on collectors transparency and it consists of using hurdles in the region between the absorber plate and the glass cover. Experimental tests were performed to evaluate the thermal convection in this region with heating at the bottom provided by using electric heaters with electronic temperature control. The results obtained for sloped cavi- ties at various angles are presented and discussed but still greater detail is presented for a 30 ◦ slope with horizontal. The results show that if these systems are properly designed they can significantly improve the efficiency of glazed solar collectors.
Keywords
Solar Energy, Flat Plate Solar Collector, Heat transfer coefficient
