不同防排烟方式下车厢火灾烟气运动的数值模拟研究

为了揭示车厢内部火灾烟气在不同防排烟方式下的迁移特征，优化选择最优防排烟方式，运用火灾动力学软件FDS对CRH2A动车组的一节车厢进行模拟计算。分别采用机械排烟系统、空气幕系统及二者复合系统对车厢内烟气进行控制，对比分析不同排烟系统下车厢内烟气温度、烟气层高度和烟气浓度的变化规律。结果表明:随着排烟量的增加排烟效果显著增大，但排烟量不宜过大，当固定功率为0.2 MW时，V2=0.87 m3/s排烟效果最佳；空气幕在一定程度上可以阻挡烟气蔓延至相邻车厢，机械排烟在降低烟气温度与浓度方面的效果比空气幕系统明显；每个独立系统的控烟效果远不及二者复合系统效果明显。综合考虑防排烟的有效性和经济性，在本文设定工况下，V1=1.12 m3/s、V2=1.62 m3/s为最优防排烟组合方式。

Study on numerical simulation of fire-induced smoke movement under different smoke control methods in train compartment

To reveal the migration characteristic of fire-induced smoke under different smoke control methods in train compartment and select the optimal smoke control method, the simulated calculation was carried out on one compartment of the high-speed train CRH2A by using FDS (Fire Dynamic Simulation). The smoke in the compartment was controlled by mechanical smoke exhaust system, air curtain system and the coupled system of them respectively, and the change laws of smoke temperature, smoke layer height and smoke concentration in the compartment under different smoke control system were compared and analyzed. The results showed that the effect of smoke control is better with the increase of mechanical smoke exhaust rate, but the mechanical smoke exhaust rate should not be too large, when the fixed fire power is 0.2 MW, the smoke exhaust effect is the best when the mechanical smoke exhaust rate(V2) is 0.87 m3/s. The air curtain can impede the spreading of smoke to adjacent compartment to some extent, and the effect of mechanical smoke exhaust on reducing smoke temperature and concentration is more obvious than that of air curtain system, but the effect of each independent system is far less than that of the coupled system. Comprehensively considering the effectiveness and economics of smoke control, the optimal combination mode of smoke control was the air curtain rate (V1) is 1.12 m3/s and the mechanical exhaust rate (V2) is 1.62 m3/s under the conditions of this paper.