Study on thermo-electrical performance of spray-cooled concentrating photovoltaic system using oleic acid modified nanofluid

Abstract

In the utilization of solar photovoltaics, concentrated photovoltaic technology can effectively improve the efficiency of solar cells, but it is limited by the problems of contact thermal resistance and low thermal conductivity of working fluid in cooling technology. This article proposes a modified nanofluid spray cooling HCPV system, which not only overcomes the low heat carrying capacity of traditional working fluids, but also solves the problem of contact thermal resistance in the heat transfer process, further reducing the cell temperature to achieve higher heat transfer efficiency and electrical efficiency. At first, oleic acid (OA)-modified Al2O3 nanofluids (OA-Al2O3-H2O/C2H6O) were prepared. Otherwise, stability test methods and spray cooling heat transfer test benches were developed and built. Finally, the stability of nanofluids, the temperature field distribution and electrical efficiency of solar cells under high energy current density were tested, and the effects of flow rate and base-liquid ratio on system performance were analyzed. The results showed that: OA can keep Al2O3-H2O/C2H6O nanofluids more than 48 h, and the surface temperature is stable at 40 °C. Meanwhile, the electrical efficiency is always above 27 %, up to 29.37 % and 1.3 % higher than working fluid water.