Analytical investigation of photovoltaic thermal system under external recycle: A comparative study

In this paper, the performance of two different designs under external recycling photovoltaic thermal system (PV/T) is analyzed with a steady-state model theoretically. The first design contains PV cells with glass, and the second design containing PV cells without glass. The mathematical model that depicts the divergence in the temperatures and heat transfer characteristics of such a PV/T system under external recycling has been developed and used to study the effects of recycle ratio of different mass flow rates, varying channel depth, and packing factor on electrical, thermal, and combined efficiency. The two different configurations selected in the current study are new so that no PV/T recycling system was ever attempted previously. The results show that the first design has superior performance over the second design, but when we increase the packing factor at a high recycle ratio and mass flow rate, the electrical performance of the second design is more as compared to the first design. Important parameters for the proposed techniques are identified, and their effects on the performances are presented in detail. Copyright (C) 2021 Elsevier Ltd. All rights reserved.