Study on Combustion Characteristics of Flexible CIGS Photovoltaic Cells Under Different External Wind Conditions

This paper investigates the influence of external wind on the combustion and flame spread behavior of flexible copper indium gallium selenide (CIGS) photovoltaic cells. Combustion experiments were conducted at a fixed inclination angle of 20° under varying wind speeds ranging from 0 to 4 m/s. Multiple diagnostic techniques, including high-speed videography, thermocouple measurements, and heat flux gauges, were employed to analyze key combustion parameters such as flame morphology, surface temperature distribution, and radiative heat flux. The results reveal a critical wind speed effect at approximately 2.5 m/s. Below this threshold, increasing wind speed significantly enhances combustion intensity. The maximum frontal flame spread rate reached 1.27 cm/s at 2.5 m/s, while the radiative heat flux increased from 71 kW/m2 to 90 kW/m2. Beyond this critical value, the flame spread rate decreased, and at 4 m/s, sustained frontal flame propagation was not maintained, with radiative heat flux dropping to 50 kW/m2. Furthermore, the flame spread rate on the rear side of the panel consistently exceeded that on the front side, peaking at 1.5 cm/s under 2.5 m/s wind conditions. This study elucidates the impact of wind speed on the combustion behavior of flexible photovoltaic cells and provides a foundation for fire safety assessments.