A novel air-assisted spray cooling approach using water–acetone mixtures for enhanced photovoltaic thermal management

Abstract

The increasing demand for sustainable energy has highlighted the need for advanced thermal management in photovoltaic (PV) systems. Excess heat accumulated on PV surfaces reduces carrier mobility and output voltage, thereby limiting energy conversion efficiency. Therefore, innovative cooling strategies that enhance heat transfer while maintaining economic feasibility are crucial for next-generation solar technologies. Various methods, including finned surfaces, phase-change materials, liquid films, and sprays, have been proposed for PV cooling, with air-assisted sprays standing out due to their high heat transfer and low energy demand. However, most existing air-assisted spray cooling studies have focused on pure water, ethanol, or nanofluids, while the thermal behavior of water–acetone binary mixtures remains insufficiently investigated. In this study, an air-assisted spray cooling system using water–acetone mixtures containing 0–45% acetone was experimentally and numerically examined. Four different nozzles were tested, and pressure-fed full-cone nozzles were found to produce smaller droplets and achieve higher heat transfer coefficients. Experiments were conducted under approximately 1000 W/m² irradiance, with a constant air flow rate of 4 m³/h and liquid flow rates between 150 and 800 mL/min. CFD results showed strong agreement with experimental data, with temperature deviations below 2 °C and time differences under 10%. Increasing the liquid flow rate and acetone content reduced the cooling time from 320 s (pure water) to 77 s. Owing to rapid evaporation, 400–600 mL/min flow rates and 15–30% acetone mixtures provided 9–22% faster cooling with only 190–380 USD additional annual operating cost.