热浮力及室外风压耦合驱动下高层建筑疏散走廊烟气运动网络模拟分析

Network simulation for the smoke movement in the corridor of high-rises under the coupling effects of the thermal buoyancy and wind pressure

火灾发生后,火灾烟气主要通过疏散走廊向建筑的其他部位蔓延。有效控制疏散走廊中的烟气,可以阻止其进一步蔓延到楼梯间。了解火灾烟气在疏散走廊中的运动规律,是控制其蔓延扩散的前提。热浮力和室外风压是烟气在走廊中运动的主要驱动力,研究二者耦合作用对走廊中烟气运动的影响,对进一步弄清火灾烟气的流动规律具有较大的意义。采用网络模拟软件CONTAM 3.0模拟疏散走廊中火灾烟气在上述两种驱动力作用下的运动情况。结果表明,随室外风速增大,疏散走廊中火灾烟气的运动速度增大,远大于单纯热浮力作用时烟气的运动速度;当热浮力和室外风压耦合驱动时,室外风压对烟气运动的影响起主要作用。

This paper is aimed at presenting the results of our simulation study on the smoke movement under the coupling effect of the thermal buoyancy and wind pressure in the corridor of highrises. During a fire in the high-rise building,smoke spread to other parts of the building through the corridor,and seriously threaten the lives of the people in the building. So it is necessary to understand the law of the smoke movement in the corridor and how to control its spreading. In order to enhance our knowledge of the laws of the smoke movement in the corridor under the two driving forces,this paper intends to simulate the smoke-fire moving situation under the influence of the thermal buoyancy and wind pressure by using a network simulation software CONTAM3. 0 to analyze the main driving forces and working out the coupling effect of the two driving forces. Since CONTAM 3. 0 takes each node as a uniform condition from the beginning to the end,the conditions it describes may include the temperature,the pressure,the contaminant concentrations,etc. The corridor was supposed to be divided into 28 nodes in the same area,so that it would be convenient to set the temperature changed as an exponential decay in the corridor. Furthermore,we have simulated 12 kinds of conditions to study the law of the smoke movement,including the temperature varieties between the corridor and the onfire rooms under different wind velocities. The results of our simulation demonstrate that the velocity of the smoke flow in the corridor tends to increase with the increase of the thermal buoyancy and the wind velocity. When the wind velocity exceeds 4 m / s,the wind-induced smoke would begin to flow at a much faster velocity than that induced by the thermal buoyancy. As compared with the increase in the velocity of smoke flow induced by the increase of the thermal buoyancy,the smoke-fire would begin to move much faster than that induced by the increase of the wind velocity,which is supposed to be done under the coupling effect of the thermal buoyancy and the wind pressure. Therefore,the wind pressure is deemed to play the dominant function in the coupling effect of the thermal buoyancy and wind pressure.