阻塞效应下隧道火灾顶棚最高温度的实验分析

隧道火灾时拱顶最高烟气温度的预测对于隧道防火安全设计具有很重要的意义。通过1/10隧道火灾缩尺模型实验得到了不同火源热释放率、不同通风速度下隧道顶棚最高温度测试值,并与现有的温度模型预测值进行了对比,发现现有模型对于无风及风速较小的情况,或多或少存在缺陷。另外在实际情况中车辆通常占据一部分的隧道断面积,所形成的阻塞效应不可忽略。为此,进行了不同阻塞比情况下的实验,发现现有的温度模型与不同阻塞比下的实验数据相差较大。最后,基于本文实验数据对Kurioka温度模型进行了修正,所提出的修正模型与已有的其他实验数据吻合也较好。

Experiment Analysis on the Maximum Smoke Temperature nearTunnel Ceiling in Tunnel Fire under the Blocked Condition

It is very important for tunnel fire safety designer to predict the maximum smoke temperature in tunnel fires. Oil-plate fire experiments have been done in a 1/10 scaled model tunnel and the maximum smoke temperature near the tunnel ceiling under the different fire conditions (fires in different oil plate with different heat release rates and under different ventilation velocity) were measured. And the experimental data were compared with the predicted values of existing temperature difference predicting models. Results indicate that there more or less exists some defect of the predicted values by the existing model deviates from the experimental data with the cases without tunnel ventilation or with very small ventilation velocities. Since the blocking effect of existing vehicles on the tunnel fire smoke spreading cannot be ignored, some experiments have also been carried out under different blockage ratios. It is found that there are obvious differences between the existed experimental data and the maximum temperature differences predicted by models existing. Finally, the Kurioka’s correlation for temperature difference predicting was corrected by experimental data and validated by Kayili’s and Ingson’s experimental data.