Étude thermofluide de l'amélioration du rendement des collecteurs photovoltaïques par techniques de refroidissement passives

Abstract

This thesis examines the effectiveness of a passive cooling fin system in enhancing the efficiency of a photovoltaic (PV) collector under varying meteorological conditions. First, a literature review highlights the importance of accounting for meteorological factors, presents the cooling systems used worldwide, characterizes thermal and energy exchanges at the surface of PV collectors, and analyzes existing correlations that describe variations in the convective heat transfer coefficient based on different parameters. Next, a new correlation is proposed, linking the convective heat transfer coefficient to wind speed, the length over which it flows, and the turbulence index, following a detailed analysis of existing correlations. The third chapter focuses on designing a fin-based cooling system, incorporating a mechanical resistance study, a thermofluid analysis of the boundary layer on the fins, and a thermal balance assessment. Finally, the last chapter evaluates the performance of this cooling system by comparing it to the needs and potential of the studied geographical locations. This thesis introduces a new correlation for determining the convective heat transfer coefficient of PV collectors, offering greater accuracy than the conventional method based on the Nusselt number and improved applicability across diverse experimental conditions compared to linear correlations. It then presents the design of a passive cooling system consisting of 24 rows of three aluminum fins, each measuring 30 cm in length, 4 cm in height, and 2.3 mm in thickness. This system enhances convective heat transfer from the rear surface by a factor of at least 2.5, regardless of wind conditions. Lastly, the study explores PV collector cooling in different climatic regions worldwide. The findings indicate that hot countries not only have greater cooling demands but also higher cooling potential than colder regions. The cooling system also delivers more significant energy savings in warmer climates. However, its economic viability is not guaranteed in all scenarios. Therefore, this thesis recommends implementing the system primarily in environments where wind speeds are low, such as when the collector is installed on the ground in hilly areas or locations with multiple windbreaks.

Date	29 May 2025
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Daniel Rousse (Supervisor)