一种用于光伏/热系统的新型三维光-电-热耦合数值模型

Abstract Photovoltaic/thermal (PV/T) systems offer a promising solution for enhancing energy conversion performance by capturing waste heat and reducing the operating temperature of photovoltaic cells. The performance of these PV/T systems could be further optimized by numerical simulation. However, currently reported PV/T models utilize simplified models and and fail to consider the electro-thermal coupling in local areas of solar cells, thereby inadequately representing the underlying physical mechanisms. To address this issue, a novel opto-electro-thermal coupling numerical model of perovskite PV/T systems based on drift–diffusion equations is developed in this work. This model enables the investigation of the energy conversion mechanism of optical, electrical and thermal energy at grid cell level. Building on the developed model, the energy conversion performance at system level under various operational conditions is analyzed via a modified weighted total efficiency evaluation indicator . The results indicate that: the total efficiency is significantly compromised by elevated environmental temperature, with an efficiency loss of 8.45 % observed when the temperature increases by 40 °C. Meanwhile, as irradiation intensity rises, the efficiency gained from utilizing waste heat would become increasingly significant in PV/T systems. More importantly, the optimal flow rate for various irradiation intensities is also derived. This work could offer theoretical guidance for investigating more comprehensive energy conversion mechanisms and optimizing energy conversion performance for PV/T systems.