Case Studies in Thermal Engineering (Dec 2023)
Thermal response of an asphalt solar collector: Numerical and experimental validation
Abstract
This study conducts a numerical analysis and experimental validation of the thermal performance of an asphalt solar collector. Both parallel and serpentine copper tubes with a total length of 3000 mm were embedded in the middle of a 1000 × 600 × 80 mm hot mix asphalt model. The sides and bottom of the test sections were insulated to prevent heat loss to the surrounding environment. Using four values of water mass flow rate and three values of artificial solar radiation, the thermal performance of the system was examined. A mass flow inlet of 0.0038–0.035 kg/s is specified for the water inside the embedded tubes, while 600, 800, and 1000 W/m2 solar radiation is applied on the upper section of the asphalt mix during this study. The thermal response was simulated using the COMSOL Multiphysics 5.6.0.280 heat transfer module. Using a reference asphalt solar collector, the desired parameter effects were investigated independently. The experimental results showed that the efficiencies of the asphalt solar collector with serpentine bare tubes and parallel bare tubes are 53.56 % and 52.85 %, respectively. The numerical simulation reveals that there is no significant thermal effect in the area under the embedded tubes when compared to the area above the tubes that are exposed to solar radiation from above. The average error found between the numerical and experimental results for the water temperature difference inside the embedded tubes of the asphalt solar collector ranged between 6 % and 14 %. This good agreement indicated that the computational fluid dynamics model is reliable and capable of simulating the thermal response of an asphalt solar collector.
