Natural gas poses significant risks to the safe operation of utility tunnels, which house multiple critical infrastructure systems, including natural gas pipelines. To date, no full-scale gas explosion tests in utility tunnels have been published, and there is ongoing debate about whether pipelines can withstand such explosions. This study presents the first-ever 1:1-scale experiments conducted in a 710-meter-long tunnel with cross-sectional dimensions of 3.2 m × 2.6 m. Three pipelines, each approximately 25 m in length and constructed to industrial standards, were used to investigate potential damage. The experiments comprehensively captured the development of flow fields, including flame images, flame signals, temperature, and overpressure, as well as pipeline responses. Results revealed that variations in overpressure within the combustion region were driven by both positive and negative feedback loops. A significant pressure drop was also observed as airflow passed through a local expansion. The experiments further demonstrated that while pipelines within utility tunnels are unlikely to be directly damaged by gas explosions, accessories such as racks are at high risk of severe destruction. These findings offer essential insights for improving the safety design, construct, and operation of tunnel-like spaces involving flammable gases.

中文翻译：

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710米长多管综合管廊天然气爆炸全尺寸实验研究


天然气对公用隧道的安全运营构成重大风险，公用隧道内有多个关键基础设施系统，包括天然气管道。迄今为止，尚未公布综合管廊的全面瓦斯爆炸试验，并且关于管道能否承受此类爆炸的争论仍在继续。这项研究首次在 710 米长、横截面尺寸为 3.2 m × 2.6 m 的隧道中进行了 1:1 比例的实验。使用三条管道来调查潜在的损害，每条管道长约 25 m，并按照工业标准建造。实验全面捕捉了流场的发展，包括火焰图像、火焰信号、温度和超压以及管道响应。结果表明，燃烧区域内超压的变化是由正反馈回路和负反馈回路驱动的。当气流通过局部膨胀时，还观察到显着的压力下降。实验进一步表明，虽然综合管廊内的管道不太可能被瓦斯爆炸直接损坏，但机架等附件却面临着严重破坏的高风险。这些发现为改善涉及易燃气体的隧道类空间的安全设计、建造和运营提供了重要的见解。