Evaluation of different methods to ameliorate the performance of PV/T systems using hybrid nanofluids and PCM in a spiral tube with different cross sections

Abstract

This study proposes a novel design for a serpentine tube to develop an efficient photovoltaic-thermal (PV/T) system. For this purpose, three different hybrid nanofluids and two types of PCM were numerically investigated in a novel serpentine tube with different cross-sectional shapes (rectangular, circular, and triangular). The electrical, thermal, and exergy efficiencies of the PV/T system are evaluated to ascertain the feasibility of the proposed configuration and working fluid. The results showed that using PCM composite and a rectangular cross-section increased thermal and electrical efficiency by 31.1 % and 5.4 %, respectively, compared to the state without PCM and the circular cross-section.For a more comprehensive assessment, the effect of three hybrid nanofluids with a volume concentration of 1.5 % is studied to determine which nanofluid improves heat transfer. Fe3O4-MWCNT demonstrates the most effective nanofluid for cooling down the PV cell temperature. It is used with a volume concentration of up to 4.5 % to investigate how increasing the concentration of hybrid nanofluid can affect important parameters such as cell temperature, fluid outlet temperature, electrical, and thermal efficiency.Moreover, using Fe3O4-MWCNT (4.5 %) along with PCM and PCM composite increases the exergy efficiency by 13.3 % and 16.2 %.