火灾过程中羽流模型及其评价

总结了Zukoski(1)、Zukoski(2 )、NFPA、McCaffre和Thomas -Hinkley几种常见的羽流模型和适用条件 ,运用算例对几种常见羽流模型的羽流质量流量、保持一定冷空气高度条件下的热烟气层温度和排烟体积流量进行了对比分析。结果表明 ,在冷空气层高度 2m～ 3m时 ,各羽流模型的计算结果较为接近 ;在冷空气层高度较大时 ,小面积火源条件下Zukoski(1)、Zukoski(2 )、NFPA三个模型的计算结果较为接近 ,McCaffre模型计算的羽流质量流量最大 ,热烟气层温度最低 ,排烟体积流量最大 ;大面积火源条件下 ,McCaffre模型和Thomas -Hinkley模型相比 ,羽流质量流量大 ,热烟气层温度最低 ,排烟体积流量大。在相同房间高度和地板面积条件下 ,羽流质量流量大则热烟气的充填时间短

The Analysis and Estimation of the Plume Models in the Development of Fires

This article generalizes several usual types of plume models, such as Zukoski(1)?Zukoski(2)?NFPA?McCaffre and Thomas Hinkley, and their appropriate applicable conditions. Several examples are calculated to contrast and analyze some parameters of the several usual types of plume models,such as plume mass flow, the temperature of hot layer of gas under the conditions of maintaining some certain height of low layer of air,and the volumetric flow of smoke. The results indicate, that as the height of low layer of air is between 2m and 3m, the results of calculation for the different models are closer to each other, and that on the conditions of the relatively larger height of low layer of air and the fire of small surface of fuel, the results of calculation for the three models, Zukoski(1), Zukoski(2), NFPA, are also closer to each other and for the results of McCaffre model, the plume mass flow is biggest, the temperature of hot layer of gas is lowest, and the volumetric flow of smoke is biggest, and on the condition of the fire of big surface, other than small surface, of fuel, for McCaffre model, its plume mass flow is bigger, the temperature of hot layer of gas is lower, and the volumetric flow of smoke is bigger than Thomas Hinkley model. Finally, the results show that as the height of compartments and the area of floors are separately constant, the plume filling time is shortest if the corresponding plume mass flow is relatively bigger.