Performance analysis on the concentrated photovoltaic /thermal air collector with phase change material and vacuum double-glazing for temperature regulation

Although photovoltaic/thermal (PV/T) air collector has simple structure and strong pressure bearing capacity, there are problems such as low thermal efficiency, unstable output temperature, due to low heat transfer performance of air and fluctuating solar irradiation. To address the above issues, a concentrating photovoltaic/thermal air collector with phase change material and vacuum double-glazing (VDG-PCM-CPV/T) is proposed in this paper. The performance of VDG-PCM-CPV/T in three continuous days is studied and compared with the module with PCM and single-glazing (SG-PCM-CPV/T) and the module with single-glazing (SG-CPV/T) by establishing the mathematic model of the daytime and night. It is proven that VDG-PCM-CPV/T has certain advantages in alleviating the downward trend of air temperature caused by the decrease of solar irradiation, due to the constant temperature storage and heat release characteristics of PCM. At night, as the vacuum double-glazing has excellent heat preservation effect, the initial temperature of PCM in VDG-PCM-CPV/T is 5.00 °C higher than that of SG-PCM-CPV/T, enable VDG-PCM-CPV/T to obtain higher thermal efficiency in the next day. While, the electrical power of VDG-PCM-CPV/T is slightly lower than that of SG-PCM-CPV/T and SG-CPV/T. The exergy efficiency of VDG- PCM-CPV/T, SG-PCM-CPV/T and SG-CPV/T at peak is 1.70%, 1.10% and 2.00%, respectively.