Performance of an air-cooled photovoltaic/thermal system using micro heat pipe array

Abstract

The performance of an air-cooled photovoltaic/thermal (PV/T) system based on micro heat pipe arrays (MHPAs) proposed in this paper was experimentally studied and analyzed. The results show that the MHPA-PV/T system has an excellent cooling effect under transient state. The temperature of PV cells can be decreased by 22.8 °C, and the power generation efficiency is increased by 30.9 %, while the corresponding temperature difference along the MHPA direction was only 0.77 °C. The temperature in the air duct increased by 34.1 % and presented a sharply upward trend in the early stage of operation, which was positively correlated with the solar irradiation. The overall efficiency was improved when the air mass flow rate increased from 0.0343818 kg/s to 0.0987572 kg/s, however, the increase in power generation efficiency was negligible compared to the increase in heat collecting efficiency. When the air mass flow rate was 0.0987572 kg/s, the power generation efficiency, heat collecting efficiency and overall efficiency were 38.12 %, 13.0 % and 65.90 %, respectively. According to the temperature under different air mass flow rate, it can be concluded that the temperature difference between inlet and outlet decreases with the increase of air mass flow rate. In addition, the system performance in different seasons was also analyzed. The research results will provide theoretical basis and data support for the practical application of the MHPA-PV/T system, and it is of great significance to achieve the strategic goal of “carbon peak and carbon neutrality” of China.