Design and dynamic performance of a concentrated photovoltaic system with vapor chambers cooling

One of the challenges faced by concentrated photovoltaic (CPV) system is the thermal management of the CPV module because it can seriously degrade and even shorten the lifetime of the CPV cells. Vapor chamber as a twodimensional heat pipe has drawn attention for use in cooling electronic devices. In this research, vapor chambers cooling is proposed for a CPV system based on multi-segment mirror concentrator to ensure the operation of CPV module at low and uniform temperature. Ray tracing analysis shows that the developed concentrator exhibits optical efficiency of 74% at concentration ratio of 30 suns and the concentrated solar flux intensity distribution on the CPV module surface is quite uniform. To maximize the electrical energy output, the dynamic performance of the linear CPV system with vapor chambers cooling by varying the thickness of the vapor space, the vapor chamber width and the concentration ratio is analyzed. The results indicate that the vapor space thickness of 3.5 mm and the vapor chamber width of 250 mm are the optimum to achieve the best system performance. Further, it is found that the temperature of CPV cells with vapor chambers is 17.5 K lower than that without them, resulting in improvement in the system electrical performance. The maximum instantaneous CPV cells temperature of the system with the designed vapor chambers cooling under 30 suns concentration can be maintained as low as 323.8 K in a typical day and the minimum electrical efficiency and the average electrical efficiency for the whole day are 13.9% and 14.4%, respectively.