A Study on Fire Hazards of Building-Integrated Photovoltaic Systems with Double-Skin Facades

Description

Building-integrated photovoltaic (BIPV) systems with photovoltaic (PV) modules installed in the cavity of a double-skin facade (DSF) are becoming popular. However, buildings with a DSF have difficulties complying with fire safety codes in some countries. When a building catches fire, burning PV panels can contribute to an already very hazardous environment. In some cases, cutting off the electricity generated by PV panels has proved problematic, and vast quantities of toxic gas have emitted from burning PV panels and associated combustible components. Although PV cells at roof level are stable under normal building fire temperatures, their behaviour during fires when they are installed in the cavity of a DSF is unknown, as the air temperature in a DSF cavity can be very high when it is located next to a flashover room fire. Furthermore, large amounts of PV modules are typically installed in BIPV systems.The major aim of this project will be to conduct a thorough investigation of the fire hazards of BIPV systems with DSFs. The thermal environment in a facade cavity when the interior glass pane is broken due to a flashover fire in a room adjacent to the facade will be examined using scale model experiments and full-scale burning tests on part of a BIPV system with a DSF. The results will be applied to investigate the possibility that the selected PV modules and the combustible accessories installed in the facade cavity will ignite. Samples of the crystalline and thin-film silicon PV modules commonly used in BIPV systems will be selected to examine their behaviour in big post-flashover room fires. The heat and smoke emitted from PV modules exposed to experiment-based radiative heat fluxes will be evaluated by a cone calorimeter. The smoke-potency fractional exposure dose will also be measured. The spread of the smoke and heat emitted from the burning PV modules installed in the facade cavity will then be examined. A real-scale model of part of a BIPV system with a DSF will be constructed to justify the results of the thermal environment in scale modelling experiments. Mathematical models of heat and mass transfers, including computational fluid dynamics, will be combined with the experimental results to achieve the integrated understanding necessary to provide fire-safe BIPV systems with DSFs. Appropriate fire protection, firefighting and rescue strategies for BIPV systems with DSFs can then be recommended.