Analysis of the output characteristics of a low-concentration photovoltaic/ thermal system based on a new three-dimensional optical-electrical-thermal multiphysics coupling model

This study introduces a novel multi-focus segmented compound parabolic concentrator (CPC) and develops a low-concentration photovoltaic/thermal (LCPV/T) system based on this design. Additionally, a new threedimensional optical-electrical-thermal multiphysics coupling model is proposed. A comparative analysis between the traditional CPC and multi-focus segmented CPC is performed, focusing on surface energy flux density, temperature distribution, and operational costs. The variations in photovoltaic panel temperature, output power, and exergy efficiency of the LCPV/T system under varying operating conditions were investigated. The results show that the multi-focus segmented CPC significantly improves the uniformity of energy flux density and temperature distribution on the photovoltaic panel. Under 1000 W/m2 irradiance, the energy flux density ranges from 1845 W/m2 to 7586 W/m2. Furthermore, photovoltaic conversion efficiency decreases with increasing irradiation, while total exergy efficiency exhibits an upward trend. It is found that the inlet cooling water temperature is the primary factor influencing thermoelectric performance. Furthermore, as the inlet flow rate increases, photovoltaic conversion efficiency decreases following a power-law trend, while thermal efficiency and total exergy efficiency increase in a power-law manner. This study offers valuable insights for optimizing LCPV/T system design and improving overall energy utilization efficiency.