Electrical cabinet fires are one of the main fire hazards in nuclear power plants (NPPs). The electrical cabinets are often arranged in rows of adjacent cabinets (ACs) in NPPs. So the ability of a cabinet fire to spread to ACs is a major concern for fire safety. This work aims to investigate the impact on the fire spread of the air gap between two electrical cabinets, the electrical component type contained in the AC, and its ventilation mode. For that purpose, a test device composed of two adjacent steel enclosures was designed in order to reproduce at reduced‐scale adjacent electrical cabinets. This study first reveals that the studied electrical component types spontaneously ignited when their temperature and the incident heat flux reach critical ignition values. These ignition criteria are assessed for each component type. The tests also show that the air gap increase slows down the rise of the side wall temperature of the two enclosures, which delays the ignition time of the electrical components. This work finally highlights that the mechanical ventilation of the adjacent enclosure (AE) has an impact on the ignition conditions. In contrast, the natural ventilation as implemented in the AE has a small effect on these conditions.

中文翻译：

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电气元件在受控火源附近的密闭空间中着火

电气柜火灾是核电厂（NPP）的主要火灾隐患之一。电气柜通常以NPP中的相邻柜（AC）的行排列。因此，橱柜火灾蔓延到AC的能力是消防安全的主要考虑因素。这项工作旨在调查两个电气柜之间的气隙，交流电中包含的电气组件类型及其通风方式对火势蔓延的影响。为此，设计了一个由两个相邻钢制外壳组成的测试设备，以便在缩小规模的相邻电气柜中进行复制。这项研究首先揭示出，当所研究的电气元件类型的温度和入射热通量达到临界点火值时，它们会自燃。这些点火标准针对每种组件类型进行评估。测试还表明，气隙的增加减缓了两个外壳的侧壁温度的上升速度，从而延迟了电气组件的着火时间。这项工作最终突显出相邻机柜（AE）的机械通风会对着火条件产生影响。相反，在AE中实施的自然通风对这些条件的影响很小。