A set of experimental tests were conducted to investigate the maximum gas temperature rise and longitudinal temperature distribution beneath the centerline ceiling in a portals-sealed arched tunnel, taking fuel tank central angle location along the sidewall (expressed by effective ceiling height) and linear fire size into account. A linear fuel tank burner, placed on the arched sidewall of the tunnel, was utilized to simulate the fire source. A new empirical formula was proposed to predict the maximum excess temperature beneath the ceiling in a portals-sealed tunnel fire, based on dimensional analysis. The experimental results show that the non-dimensional maximum excess temperature has an exponential decaying relationship with non-dimensional fuel tank length. A predecessor's equation is modified to present the longitudinal temperature distribution beneath the centerline of arced-ceiling in a portals-sealed tunnel fire, which is consists of the sum of two exponential equations. The comparison of longitudinal temperature distribution between fire in portals-sealed tunnel and natural ventilation tunnel was conducted. The study is expected to provide some references for actual tunnel fire-fighting.

进行了一组实验测试，以研究门式密封拱形隧道中心线顶棚下的最大气体温度升高和纵向温度分布，并沿着侧壁（以有效顶棚高度表示）为燃料箱中心角位置，并确定线性火势考虑在内。放置在隧道拱形侧壁上的线性燃油箱燃烧器用于模拟火源。根据尺寸分析，提出了一个新的经验公式来预测门型密封隧道火灾中天花板下方的最大过剩温度。实验结果表明，无量纲最大超温与无量纲燃料箱长度呈指数衰减关系。前辈 对s方程进行了修改，以显示门式密封隧道火灾中弧形天花板中心线下方的纵向温度分布，该温度分布由两个指数方程之和组成。进行了门式密封隧道与自然通风隧道火灾纵向温度分布的比较。该研究有望为实际的隧道灭火提供参考。