Abstract The horizontal flame spread underneath a photovoltaic (PV) module (or a plate) was studied for various gap heights to understand the fundamental fire dynamics between it and a flat roof construction. In a number of experiments, an opaque black polymethyl methacrylate (PMMA) and a black stainless-steel plate were used as surrogate fuel and module, respectively. Additional experiments were conducted with actual PV modules to analyse the reproducibility of the surrogate results and to study the potential effect of the small fuel contribution from the PV modules. PMMA samples (70 cm long) of varying widths (20 cm, 30 cm and 40 cm) were ignited at one end, and flame spread rate, mass loss, radiative heat flux and temperatures were recorded. For the 30 cm wide samples, a reduction in gap height from 20 cm to 17 cm resulted in a significant increase in the flame spread rate (from 0.37 mm/s to 2.41 mm/s). A similar critical gap height (transition into a much faster flame spread rate) was identified for all widths. Thus, introducing gap height requirements into PV installation standards could offer an inexpensive and elegant design that could reduce the fire risk associated with PV modules on flat roofs significantly.

中文翻译：

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光伏（PV）模块下方火焰蔓延的实验研究

摘要 研究了不同间隙高度下光伏 (PV) 模块（或板）下方的水平火焰蔓延，以了解其与平屋顶结构之间的基本火灾动力学。在许多实验中，不透明的黑色聚甲基丙烯酸甲酯 (PMMA) 和黑色不锈钢板分别用作替代燃料和模块。使用实际 PV 模块进行了额外的实验，以分析替代结果的再现性并研究来自 PV 模块的小燃料贡献的潜在影响。在一端点燃不同宽度（20 厘米、30 厘米和 40 厘米）的 PMMA 样品（70 厘米长），并记录火焰蔓延速度、质量损失、辐射热通量和温度。对于 30 cm 宽的样品，间隙高度从 20 cm 减少到 17 cm 导致火焰蔓延速度显着增加（从 0.37 mm/s 到 2.41 mm/s）。对于所有宽度都确定了类似的临界间隙高度（转变为更快的火焰蔓延速度）。因此，在光伏安装标准中引入间隙高度要求可以提供一种廉价而优雅的设计，可以显着降低与平屋顶光伏组件相关的火灾风险。