Experimental Study of a Solar Air Heater with Copper Wool Integrated on the Absorber Plate

Abstract

This study presents an experimental investigation into the performance enhancement of a solar air heater by incorporating copper wool on the absorber plate. Solar air heaters are critical components in solar thermal systems, commonly used for space heating, drying agricultural products, and other applications where thermal energy is required. However, the efficiency of conventional solar air heaters is often limited by the thermal conductivity and heat transfer capabilities of the absorber plate. This research aims to address this limitation by integrating copper wool—a material known for its high thermal conductivity—onto the surface of the absorber plate to improve heat absorption and transfer.

The experimental setup involved a flat plate solar air heater, modified with a layer of copper wool attached to the absorber plate. The solar air heater was tested under various operating conditions, including different air flow rates and solar irradiance levels, to evaluate its thermal performance. Key parameters such as the air inlet and outlet temperatures, absorber plate temperature, and the overall thermal efficiency of the system were measured and analyzed.

Results from the experiments showed a significant improvement in the thermal performance of the solar air heater with copper wool on the absorber plate compared to a conventional solar air heater without the modification. The copper wool enhanced the heat transfer from the absorber plate to the air, leading to higher outlet air temperatures and increased thermal efficiency. Specifically, the modified solar air heater exhibited a thermal efficiency increase of up to 15% under optimal conditions. The study also found that the effectiveness of the copper wool in improving heat transfer was more pronounced at higher air flow rates, indicating its potential for use in high-demand thermal applications.

In addition to thermal efficiency, the study assessed the impact of the copper wool modification on pressure drop across the solar air heater. It was observed that the presence of copper wool slightly increased the pressure drop, a factor that must be considered when designing and optimizing solar air heaters for practical applications. The trade-off between increased thermal efficiency and the accompanying pressure drop suggests the need for careful design and material selection to balance these factors.

Keywords

solar air heater, copper wool, absorber plate, experimental study, thermal performance, heat transfer