Cooling performance of sliver solar cells in low concentration PV system with ribbed-groove mini-channel heat sink

Abstract

This paper presents a numerical investigation of a cooling system designed for concentrated photovoltaic (PV) systems. To enhance the performance of system and reduce operating temperature, mini-channels have been integrated onto the PV cells. Heat transfer improvement in these mini-channels is proposed by integrating ribbed grooves in a parallel alignment on their sidewalls. Water is used as a cooling fluid having laminar flow regime maintained within the Reynolds number between 100 and 500. The mini-channel is subjected to a constant heat flux, and various parameters, such as rib height, pitch, and angle are examined in order to assess their impact on Nusselt number, thermal resistance, temperature fluctuations, and friction factor variation. Subsequently, by identifying the optimal rib dimensions, the rib arrangement is further investigated. Results demonstrate that compared to a smooth channel, the presence of ribs reduces thermal resistance by up to 25.9 % as the Reynolds number increases. Furthermore, increasing rib height induces more vortices behind the obstacles, enhancing heat transfer between the fluid and channel walls. Additionally, by altering the rib arrangement, thermal resistance decreases significantly, with the maximum reduction of 32.14 % observed in the case of a two-blade configuration. Moreover, the integration of blades leads to a maximum 111.96 % increase in the Nusselt number compared to a smooth channel. In this context, the 2-blade and 4-blade configurations result in a maximum reduction of 6.48 K in the channel base temperature compared to the optimized ribbed mini-channel. These findings offer valuable insights into enhancing the performance of concentrated PV systems through innovative cooling strategies.