基于标准火灾曲线和热释放率的衬砌温度分布数值计算研究

Numerical calculation of temperature distribution of lining based on standard fire curve and heat release rate

为探明火灾下衬砌温度的分布特性,基于隧道火灾-衬砌辐射对流传热数学模型建立了衬砌温度数值计算方法,并对HC标准火灾曲线和30 MW火灾热释放率火灾工况进行计算分析。结果表明,标准火灾曲线最高温度普遍大于目前我国规范的要求。采用火灾温度作为衬砌壁面边界条件将显著增大衬砌温度荷载,2小时HC火灾曲线和30 MW火灾工况衬砌最高温度分别为778℃和351℃。标准火灾曲线工况衬砌内部的高温影响范围和高温值均显著大于30 MW火灾工况。

In order to find out the temperature distribution charac-teristics of the lining under fire,a one-dimensional numerical cal-culation method of heat transfer lining temperature was estab-lished based on the mathematical model of tunnel fire-lining radia-tive convective heat transfer.The HC standard fire curve and the fire condition of 30 MW fire heat release rate were calculated and analyzed.The results show that the maximum temperature of the standard fire curve is generally greater than that required by the current Chinese code.Using fire temperature as the boundary con-dition for the lining wall will significantly increase the temperature wad on the lining.The maximum temperature of the lining is 778℃ and 351℃ under the 2 hour HC fire curve and the 30 MW fire condition,respectively.The influence range and high temperature value of the lining inside the standard fire curve condition are sig-nificantly greater than those of the 30 MW fire condition.