Experimental Study of an Optimized Evacuated Tube Collector with Wavy Tape and Phase Change Material for Hot Water Production

This study evaluates the performance of four configurations of an evacuated tube solar collector (ETSC): conventional ETSC, ETSC with wavy tape (WT), ETSC with phase change material (PCM), and ETSC with a combination of PCM and WT. The novelty of this research lies in integrating a binary eutectic PCM and analysing the combined effects of PCM and WT on ETSC performance. The results indicate that the highest hourly efficiency, 71.75%, is achieved with the ETSC incorporating both PCM and WT, followed by 67.63% for ETSC with WT, 65.5% for ETSC with PCM, and 60.61% for the conventional ETSC. The daily average efficiency for these cases is 35.17%, 39.90%, 40.32%, and 45.92%, respectively. Similarly, exergy efficiency follows the same trend, with the ETSC featuring both WT and PCM achieving the highest average exergy efficiency of 6.11%, compared to 3.48% for the conventional ETSC, 4.43% for ETSC with WT, and 5.09% for ETSC with PCM. An environmental analysis based on energy and exergy approaches further reveals that the ETSC with PCM and WT mitigates the highest amount of CO₂ emissions per ton compared to the other configurations.