nvestigating the effect of needle ribs on parabolic through solar collector filled with two‑phase hybrid nanofluid

Abstract

The sun is a non-renewable resource that helps reduce carbon dioxide emissions and reduces the impact of industries on nature pollution. Therefore, using solar energy in various industries is always highly important. This study investigates the effect of using needle ribs (NR) in different geometric modes of height and diameter in parabolic through solar collector (PTSC). Also, the H 2 O/Fe 3 O 4 –CNT hybrid nanofluid (HNF) is used as a heat transfer (HT) fluid in the PTSC, assuming a two-phase approach (TPA) in Reynolds number (Re) 24,000–96,000. NR in the height of 3, 6, and 9 mm, as well as diameters of 1.5, 2.5, and 3.5 mm, are modeled, and their effect on different parameters in the output of PTSC is investigated. Based on the obtained results, the use of NR on the wall of the PTSC causes the HNF flow to change shape and increases the thermal efficiency (TE) in the PTSC. The higher the height and diameter of the NR, the greater the density of the flow lines and, as a result, the higher the speed and flow rate. The highest increase in thermal performance (TP) is related to the geometry of NR with a height of 9 mm and a diameter of 3.5 mm. In fact, in this case, the TP increases by 49.85% compared to when the inner surface of the PTSC is smooth. Increasing the height and diameter of the NR affects and increases the efficiency and energy efficiency (