Experimental Study of the Solar Air Heater Performance with Evacuated Tubes Connected in Series and Involving Nano-Copper Oxide / Paraffin Wax as Thermal Storage Enhancer

Abstract

<title>Abstract</title> The investment of solar energy in life applications has become mandatory in order to maintain a clean environment and reduce the use of fossil fuel. In this work, the performance of solar air heater is aimed to be improved with the help of evacuated tube solar collectors. To achieve this purpose, a system consisting of 5 linked collecting panels was designed, fabricated, and experimentally tested. Each panel included a glass-evacuated tube with two concentric aluminum tube installed inside. The system was reinforce by adding paraffin wax as a PCM and boosting its thermal conductivity by incorporating it with copper oxide nanoparticles CuO. The performance was investigated with and without Nano enhancer phase change material NE-PCM at five mass flow rates (0.006-0.008-0.05-0.03-0.01 kg/s). Experimental results revaluated that the highest temperature was recorded as 116°C at a mass flow rate of 0.006 kg/s. The maximum thermal efficiency with storage material was 38% at 0.05 kg/s, and the pressure drop was about 2.2kPa.