Experiment using High-Expansion Foaming Agent in an Underground Utility Tunnel as a Fire Suppression Method

This study conducted a discharging experiment of high-expansion foams at a real-scale experimental underground utility tunnel and proposed an effective fire response plan. The study analyzed the discharge and foaming characteristics of high-expansion foam in the event of an underground utility tunnel fire. When high-expansion foams were injected at one point, foam agents started to break out four minutes after reaching reduction time. Meanwhile, when high-expansion foams were injected at three points, the experimental tunnel was filled entirely after seven minutes using 650 L of extinguishing agent. Moreover, in the cellar nozzle experiment, discharging from a nozzle injected horizontally to a manhole was more effective than that from a nozzle vertically injected to push smoke and heat.