【作者】 仝庆贵；

【导师】 郑洁；

【作者基本信息】 重庆大学 ， 供热、供燃气、通风及空调工程， 2003， 硕士

【摘要】 本文要解决的问题:客运大楼零售店发生火灾时，是否会发生轰燃，它对整个建筑的烟气运动有何影响？现行规范有关中庭建筑防排烟设计的规定是否合理，应该如何修正补充？才能使其更好地满足实际工程需要。本文采用模型实验和计算机数值计算相结合的方法，对客运大楼、中庭火灾烟气流动及其影响因素进行了研究。主要包括以下几方面内容并得出了相关的结论：以香港理工大学和中国科技大学合建的火灾实验厅为原型，按1/8 比例建造了客运大楼零售店火灾相似模型实验台，开展了有关客运大楼零售店火灾时轰燃产生的条件以及对整个大空间建筑的影响的实验。实验结果表明：大空间内的小室发生火灾时，容易发生轰燃；轰燃时，整个小室变成了一个大的热源，产生的烟气量也大大增加，整个大空间内的烟气层下降迅速。建立了火灾烟气运动数学物理模型。采用浮升力作用下火灾烟气紊流流动场模型，将着火区域处理为体积热源。应用PHOENICS程序对客运大楼零售店火灾进行数值实验，并将数值计算结果与模型实验结果进行了对比，对比结果表明该程序可以用于火灾模拟。不同形式中庭火灾数值计算的结果表明：按规范所规定标准设计的排烟系统,瘦高型中庭一般不能达到理想的排烟效果；立体型或扁平型一般能达到预期的排烟效果；体积超过17000m3的中庭（瘦高型除外）能达到预期的排烟效果。瘦高型中庭火灾数值计算结果表明：瘦高型中庭发生火灾时，在其顶部容易形成热空气层，使排烟效率降低；排烟量至少增大为规范所规定的1.3倍以上，方能达到良好的排烟效果；单独增加排烟口数量，可以使烟气层提高，但不明显；排烟量和风口数量同时增加，排烟效果则更加理想；所增加的风口最佳位置建议最好设置在中庭高度2/3处。更多还原

【Abstract】 What this thesis tries to solve are: when fires occur in retail shops of the terminal halls, flashover happens or not and what’s kind of effect it will have on the smoke movement in the whole building; whether the current code about the exhaust smoke design of the atrium are reasonable or not and how to amend and make them comply with the needs in practical projects.This thesis adopts the method which combines model experiment with computer numerical calculations and studies the smoke flow in terminal halls and atria and the affecting factors. It mainly includes the following aspects and arrives at corresponding conclusions: An experimental reduced-scale compartment, which is based on a 1/8-scale model developed by the PolyU/USTC, is established. The experiments are carried out on the conditions of flashover and its influence on the big halls during the retail shop fires. The results indicate that flashover occurs easily in small rooms; In case flashover occurs, the small room becomes a big thermal source and the produced smoke volume will then increase greatly and the smoke layer descends rapidly in the big hall.The field model for smoke flow has been established. The experiment adopts the model of the fire flue gas turbulence flow under the action of the buoyancy and the fire area is taken as a volumetric heat source. It applies the program PHOENICS to the numerical experiments. Then the numerical results are compared with that of the model experiments, verifying that the program is applicable. The numerical results about the fires in different shaped atria indicate that, according to the standard smoke exhaust system designed by the current code, thin-tall atria cannot usually obtain an ideal result; while the cubic or oblate atrium can generally and the atria whose volume exceeds 17000 m3 (except thin-tall atria ) can.The numerical results about the fires in thin-tall atria indicate that there exists a hot-air layer at the top commonly when fires happen; the layer will reduce the efficiency of the smoke exhaust system; when the quantity of smoke exhaust is augmented to at least 1.3 times prescribed in the standard of the existing code, the smoke exhaust system can get fine result; only adding exhaust outlets can raise the smoke layer, but not obviously; if both the quantity of smoke exhaust and the number of exhaust outlets are increased simultaneously, the efficiency of the smoke exhaust system becomes much <WP=6>more ideal, and it is advisable to place the added outlets on the plane of 2/3 height of the atria above the ground level.更多还原