Integration of Hybrid Porous Casting in Solar Receivers to Increase Solar Systems Efficiency

Abstract

Concentrated solar thermal (CST) technologies have been considered a promising solution to achieve carbon neutrality by 2050. However, to make CST systems attractive to the international energy sector, their efficiency must be enhanced and low-cost manufacturing processes should be used. In this context, an innovative solar receiver for parabolic-dish solar concentrators is developed in this work, focusing on the improvement of the absorption capacity and heat transfer to the thermal fluid. To enhance solar radiation absorption, a pyramid-shaped texture surface is constructed. In addition, the multiple jet impingement process combined with porous media is applied to ensure high heat transfer rates to the thermal fluid. To evaluate the system efficiency, an experimental setup is developed using a parabolic reflector with a solar tracking system and the flow dynamics of multiple jets impinging on the porous surface is analyzed using Particle Image Velocimetry (PIV). The results show that the tested absorber surface increases the solar absorption efficiency by 6.5 %, compared to the smooth surface. Furthermore, the jet’s flow dynamics and heat transfer analysis shows that the porous surface combined with the air jets increases the heat transfer rate, obtaining optimal values for jets velocities ranging between 5 and 10 ms−1.