Thermal performance of the evacuated tube solar collector (ETSC) using (PCM) with different fluid flow rates

This paper studied the experimental and numerical effects of velocity fluid flow in copper pipe fixed inside the evacuated tube solar collector (ETSC). Two cases were studied, the first filled the evacuated tube with the paraffin wax as phase change material (PCM) to modify the internal structure of the evacuated tube to enhance heat transfer and the second without (PCM). The thermal analysis collector for the different fluid velocities was studied numerically by employing ANSYS software (V.21). A decent understanding of the mathematical and trial results, demonstrates the validity and stability of the warm model. The outcomes showed that the best fluid speed was 0.015 m/s for the two kinds of cylinders. The numerical and experimental results showed that the amount of stored heat in the tube filled with wax is better, as well as the time to push out the heat is more after the absence of the sun.