Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
INFLUENCE OF THE INLET TEMPERATURE ON THE EFFICIENCY OF A FLAT-PLATE SOLAR COLLECTOR DURING ONE YEAR IN BRAZIL
Submission Author:
Bárbara Neves , MG
Co-Authors:
Bárbara Neves, Hairton Júnior José da Silveira, Cristiana Brasil Maia
Presenter: Bárbara Neves
doi://10.26678/ABCM.COBEM2021.COB2021-0057
Abstract
The increase of the energy demand, along with the depletion of conventional energy sources, has led to a search for renewable energy sources. Among the renewable energy resources, solar energy arises as a potential source, due to its inexhaustibility and green property. One of the most important domestic applications of the solar energy is the solar water heating system. Flat plate solar collectors are devices that convert solar radiation into heat for a wide range of applications specifically in domestic and industrial usages, such as bathing, washing and heating. They are simple in design, use both beam and diffuse components of solar radiation, do not require tracking of the sun, and require little maintenance. In this paper, a mathematical model is developed regarding the efficiency and the outlet water temperature of a flat-plat solar collector, over a year in Brazil. The dimensions of the device were defined as those of a typical collector. The software EES (Equation Engineering Solver) was used to simulate the hourly and average daily and monthly efficiencies for the city of Belo Horizonte (latitude 19°55’S and longitude 43°56’W), during the daylight hours of 365 days. The hourly incident solar radiation was predicted using the daily clearness index (Kt) based on the typical meteorological year obtained from the literature. The ambient temperature was assumed constant, and equal to the average annual value described in the literature. This paper also seeks to analyze the effects of the inlet water temperature of the system (25, 30, 35 and 40ºC) on the efficiency and outlet water temperature. It is expected that a decrease in the inlet water temperature will lead to an increase in the collector’s efficiency and to a decrease in the exit water temperature. Also, it is expected that the monthly efficiency increases with the incident solar radiation.
Keywords
Efficiency, Solar Collector, Useful gain, Inlet temperature, Clearness index
