Optical and thermal analysis of all-glass flat plate solar collector for domestic applications

Raquel Miguez de Carvalho¹; Mavd de Paula Ribeiro Teles¹; F. A. M. Lino¹; Kamal Abdel Radi Ismail¹

¹ State University of Campinas

doi:10.20906/CPS/CILAMCE2017-0632

Resumo

The challenge of this century is to find new sustainable energy sources that impact less the environment during generation and utilization. Solar and wind energy appear at the top of the list of renewable of high potential, widely available, of dominated technology and well accepted. Brazil is a country that receives over 3,000 hours per year of sunshine. However, this potential is largely unexplored and poorly tapped. Thermal comfort and hot water are responsible for the distortion of the electricity demand curves, management difficulties and high cost. They account for about 20 - 25% of the residential electricity consumption. These energy demands can be attended by available solar energy technologies resulting in reducing greenhouse gases emissions, improving the electricity demand curve besides other benefits. This paper presents the optical and thermal analysis of a novel all-glass flat plate solar collector which can produce hot water and increase passive thermal comfort. The bottom glass internal surface is reflective. Water is used as the working fluid. The collector has a length and width of 2,000 and 1,000 mm, respectively. The collector fixed inclination angle is determined for the day of biggest solar radiation in the year and the percentage of radiation from the beam intercepted is determined through the incidence angle. The numerical thermal analysis was performed using the SIMPLE algorithm. Three different glass gaps and different flow rates are considered to optimize the gap between glass sheets, the exit fluid temperature and the thermal efficiency of the collector.

Palavras-chave: All-glass flat plate solar collector; solar collector; solar energy; numerical model; renewable energy; passive thermal comfort