In order to study the effect of different configurations of photovoltaic thermal system on its performance, this paper analyzes the energy and exergy of photovoltaic thermal system with different coolant and heat exchanger configurations with numerical simulation methods. Basically, the heat transfer process between the PV panel and coolant in two different configurations, i.e., the straight tube and the wave tube. Furthermore, the temperature, energy and exergy efficiencies of the two configurations based on pure water cooling photovoltaic thermal system are compared. The results show that the wave tube has the best performance with the maximum thermal efficiency of 58.38% and the electrical efficiency of 11.41%, which are 4.37% and 3.56% higher than the straight tube respectively. In addition, the corresponding exergy efficiency is increased by 4% at the same condition. A lower concentration of CNT/water nanofluid has better performance in practical applications. When the volume concentration is 0.15%, the photovoltaic thermal system has a maximum thermal efficiency of 57.99%, and an electrical efficiency of 11.39%, the exergy efficiency is 11.95%. It is very important to configure the structure of the photovoltaic thermal system and select the appropriate nanofluid.
Keywords Photovoltaic-thermal module, Heat exchanger configuration, Nanofluid, Energy, Exergy