通风系数对钢构件的耐火性能影响研究

On the Effect of Ventilation Coefficient to the Fire Resistance of a Steel Component

为准确评估钢构件在室内火灾时的耐火性能,以室内火灾轰燃后的房间热平衡和热传导理论为基础,计算了火灾荷载为800 MJ·m^(-2),通风系数分别为0.03、0.05、0.08和0.1 m^(1/2)时的室内平均温度,以此为火作用,基于传热学基本理论,分别编程计算了方矩钢管柱在防火保护情况下的平均温度-时间曲线,对比分析了通风系数对钢构件温度的影响。结果表明:虽然通风系数较大时火灾温度较高,但由于火灾持续时间较短,钢构件最高温度较低,较通风系数较小时更偏于安全。

To accurately evaluate the fire resistance of a steel component in compartment fire, the average tempera-ture of the compartment was calculated, based on the theories of heat balance of compartment post - flashover and heat conduction, in which the fire load density was 800 MJ·m^-2 and the ventilation coefficient were 0. 03 , 0. 05, 0. 08 and 0. 1 m^1/2. Based on the theories of heat transfer, the average temperature - time curves of the quadrate steel column were calculated by program in the fire load of these temperatures of the compartment. And the effect of ventilation coefficient to the temperature of the column was analyzed. The results show that when the ventilation coef-ficient is big, the temperature of the compartment fire will be high, but, the time of the fire persisted will be short, and the highest temperature of the steel column will be low. So the steel structure will be safer in the situation.