Abstract The experimental study is conducted to investigate the heat exhaust efficiency with different shaft heights and heat release rates (HRRs) in a 1:10 tunnel model. The degree of plug-holing below the exhaust vent is considered. The smoke characteristics in upstream and shaft, such as flow velocity and smoke temperature rise, are discussed in this paper. The results indicate that the smoke movement in the upstream flow of the exhaust vent is mainly determined by the HRR of the fire and less affected by the vertical shaft height. The performance of the vertical shaft changes as the shaft height changes. Comparing constant HRR from the pool fire, the heat exhaust efficiency of vertical shafts does not increase all the time but decreases first and then increases. Furthermore, an empirical model is proposed based on the experimental results, which can be used to calculate the heat exhaust efficiency.

中文翻译：

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隧道火灾自然通风排热效率实验研究：竖井高度和放热率的影响

摘要 通过实验研究了1:10 隧道模型中不同竖井高度和热释放率(HRRs) 下的排热效率。考虑排气口下方的堵塞程度。本文讨论了上游和竖井的烟气特性，如流速和烟气温升。结果表明，排烟口上游气流中的烟气运动主要由火灾的HRR决定，受竖井高度影响较小。立轴的性能随着轴高度的变化而变化。对比池火的恒定HRR，竖井的排热效率不是一直增加而是先降低后增加。此外，根据实验结果提出了一个经验模型，