大型商业建筑下方市政十字平交通道的通风排烟数值模拟研究

发布时间：2018-05-28 13:08

本文选题：市政十字平交通道 + 通风排烟　；参考：《中国科学技术大学》2017年硕士论文

【摘要】：随着我国城市人口和机动车数量快速增长,很多城市道路交通出现拥堵状况。特别是对于山体城市重庆,地势起伏大,平地少、山路多,在交通枢纽地段,商业建筑用地往往会和道路改建策略发生冲突,此种情况下,设计者大胆创新提出道路下穿商业建筑的方案。本文研究的十字平交通道是主、辅通道在中间位置十字相交的一种较为少见的新型城市道路形式,通道上方是大型商业综合体建筑,两侧有商业店铺,通道内车流量和人流量十分繁杂,火灾隐患多且复杂难控制,一旦发生火灾,人员往往需借助十字平交通道进行疏散,因此需设置必要的通风排烟设施来提高其消防安全性。笔者通过调研,发现十字平交通道缺乏规范定性,目前类似工程案例在通风排烟设置方面没有统一的标准做法,前人研究成果也缺乏对十字平交通道内通风排烟模式的研究,需采用一定的研究方法进行论证。本文采用数值模拟软件FDS着手研究主通道内发生不同火灾规模火灾时,辅通道三种通风排烟模式的烟控效果,综合考虑不同火灾规模、火源位置、射流风机位置、射流形式、射流风速等的影响作用。模拟结果表明:(1)辅通道单侧射流、两侧同向射流和两侧相向射流作用均存在最小临界风速。火灾规模为0～30MW,最小临界风速值随火灾规模变化关系为:Y=Y0+bX,其中b的大小取决于风机射流形式。(2)两侧风机相向射流对应最小临界风速最大,烟层结构破坏严重,火场温降效果最差;单侧风机射流和两侧风机同向射流对应的最小临界风速值较小且差别不大,结合工程实际情况,考虑单侧风机射流模式为较合理优化的方式。(3)辅通道单侧风机射流所用下,主通道发生5～100MW火灾时,辅通道最小临界风速Y随火灾规模X呈指数增长关系Y=Y0+A*exp(R0*X),当火灾规模增大到90MW时,辅通道对应最小临界风速值趋于定值。针对市区道路常见火灾规模,辅通道射流风速一定时,主通道最大可控火灾规模Y与火源坐标位置X呈线性关系式Y=Y0+bX。本文对十字平交通道内烟气运动和机械通风排烟方面的研究成果可以为类似工程案例的通风排烟设计提供参考。
[Abstract]:With the rapid growth of urban population and the number of motor vehicles, many urban road traffic congestion. Especially for Chongqing, a mountainous city with large topography, less flat land and more mountain roads, in traffic hubs, commercial construction land often conflicts with the road reconstruction strategy, in which case, The designer boldly innovates and puts forward the plan of the commercial building under the road. The cross intersection channel studied in this paper is a relatively rare new type of urban road which is crossed between the main and secondary channels in the middle position. Above the channel is a large commercial complex building with commercial shops on both sides. The traffic flow and the flow of people in the passage are very complicated, the hidden dangers of fire are many and complex and difficult to control. Once a fire occurs, the personnel often need to evacuate with the help of the cross crossing, so it is necessary to set up the necessary ventilation and smoke removal facilities to improve its fire safety. Through investigation and investigation, the author found that there is no standard method for ventilation and smoke setting in similar engineering cases, and the previous research results are also lack of research on ventilation and smoke exhaust mode in cross crossing. It is necessary to adopt certain research methods to demonstrate. In this paper, the numerical simulation software FDS is used to study the smoke control effect of three ventilation and smoke exhaust modes in the main channel, considering the different fire scale, the location of the fire source, the location of the jet fan and the form of the jet. The effect of jet velocity, etc. The simulation results show that there is a minimum critical wind velocity in the one-side jet of the auxiliary channel, the two sides of the same jet and the two sides of the jet acting on each other. The fire scale is 0 ~ 30MW, and the minimum critical wind speed varies with the fire scale. The relation between the minimum critical wind speed and the fire scale is: (1) the magnitude of b depends on the fan jet form. (2) the minimum critical wind speed is the largest, and the smoke layer structure is destroyed seriously. The effect of temperature drop in the fire field is the worst, the minimum critical wind velocity corresponding to the one-side fan jet and the two side fan jet is small and little difference, combined with the actual situation of the project, Considering that the flow mode of one side fan is a more reasonable and optimized mode, when the 5~100MW fire occurs in the main channel, the single side fan jet is used in the auxiliary passage. The minimum critical wind speed Y of the auxiliary channel increases exponentially with the fire scale X, and when the fire scale increases to 90MW, the minimum critical wind velocity value of the auxiliary passage tends to be fixed. In view of the common fire scale of urban road, the maximum controllable fire scale Y of the main passage and the location of the fire source coordinate X are linearly related to the Y=Y0 bX when the jet velocity of the auxiliary passage is constant. In this paper, the research results of smoke movement and mechanical ventilation and exhaust smoke in cross crossing can be used as reference for the design of ventilation and smoke exhaust in similar engineering cases.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U453.5;U458

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