Influence of Relative Humidity on Thermal Performances of a Parabolic Trough Solar Collector

Abstract

Solar energy is considered by many as a highly prospective alternative energy source due to its ability to meet a significant portion of the world's energy demand. The effectiveness of a solar concentrator depends on operational and atmospheric conditions. This paper presents an experimental analysis of the influence of humidity coupled with inclination angle and mass flow rate on the performance of a parabolic trough solar concentrator. The parabolic trough solar collector underwent experimental testing at the LAUTECH engineering facility in Ogbomoso. It possesses a collector length of 2.1m, an aperture width of 1.2m, an adjustable rim angle of 75^o, 90^o, and 105^o, a focal length of 30 cm, a 10-liter storage reservoir, and variable flow rates of 0.0004 m³/s, 0.0008 m³/s, and 0.0012 m³/s. Temperatures were measured using a 12-channel temperature recorder (SD data logger), solar radiation was measured using a solar meter, relative humidity was measured using an environment meter,  and water was used as the working fluid. Thermal performance analysis was conducted to ascertain the impact of relative humidity coupled with tilt angle, mass flow rate, and weather conditions on the solar concentrator's effectiveness. At higher mass flow rates and a 90° tilt angle, the system has a greater thermal efficacy with weather elements such as solar intensity and relative humidity. This concentrator assists the energy industry by reducing its dependence on electricity and pollution from fossil fuels, thereby mitigating environmental and health concerns.

Keywords Parabolic Trough Collector, Heat loss, Thermal efficiency, Humidity.

DOI: 10.7176/JEES/14-1-06

Publication date: February 28^th 2024