Abstract Smoke control is a key issue in tunnel fire accidents. While jet fans have been widely used in road tunnels, mobile fans provide a good complement, due to its flexibility to operate, especially if there are no fixed jet fans present. To confirm the feasibility of a mobile fan system, full scale fire tests were conducted in Kalldal tunnel in Sweden, with fire size in the range of 1–2.6 MW and a mobile fan placed at the tunnel portal. In the tests, it takes about 4–5 min to establish full flow in the opposite direction and the final flow velocity can reach 1.5–1.9 m/s. To describe the transient behavior of flow development inside tunnel, a one-dimensional lumped theoretical model has been developed. The model takes into account the pressure losses of external wind, the stack effect of fire and friction losses over tunnel walls and two portals. The model is validated using the data from Kalldal tunnel fire tests. Results show that the model can well predict the initial and final steady state velocity, but underestimates the flow development. The model gives prediction on the safe side.

中文翻译：

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在隧道火灾中使用移动风扇

摘要 烟气控制是隧道火灾事故中的关键问题。虽然射流风机已广泛用于公路隧道，但移动风机提供了很好的补充，因为它操作灵活，特别是在没有固定射流风机的情况下。为了确认移动风扇系统的可行性，在瑞典 Kalldal 隧道进行了全面的火灾测试，火灾大小在 1-2.6 MW 范围内，移动风扇放置在隧道入口处。在试验中，建立反方向全流大约需要4-5分钟，最终流速可达1.5-1.9 m/s。为了描述隧道内流动发展的瞬态行为，已经开发了一个一维集总理论模型。该模型考虑了外部风的压力损失，隧道壁和两个入口上的火灾和摩擦损失的叠加效应。该模型使用来自 Kalldal 隧道火灾测试的数据进行验证。结果表明，该模型可以很好地预测初始和最终稳态速度，但低估了流动的发展。该模型给出了安全方面的预测。