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摘要：排烟口是火灾发生时将火场有毒有害高温烟气排出的出口，所以排烟口高度和位置以及排烟速度等参数的改变都会对排烟效果产生重要影响。本课题采用FDS火灾模拟软件对典型室内火灾进行数值模拟，研究排烟口高度、排烟速度以及排烟口位置的变化对排烟效果和喷淋响应时间的影响程度。研究结果表明：排烟效果会随着排烟口高度的升高以及排烟速度的增加而得到明显的改善。在排烟口高度不变的情况下，随着排烟速度增加烟气质量分数减少。使用较大排烟速度的排烟效果要比小排烟速度的排烟效果好，但当排烟速率大于一定数值时其排烟效果会得到抑制，这是因为过大排烟速度容易引起烟气层的紊乱，从而不能有效的排出烟气。侧面排烟方式的排烟效果低于顶部排烟方式。建筑排烟系统在排除火场热烟气的同时，也将用来启动自动喷水灭火系统的热烟气排走。因此，开启排烟系统将会影响自动喷水灭火系统的正常启动。本文的研究成果可为今后研究排烟系统对自动喷水灭火系统的影响以及排烟系统设计提供理论指导。37798
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毕业论文关键词： 排烟口高度；排烟口设置；排烟效果；自动喷淋系统；喷淋响应时间；FDS
Smoke exhaust design for fire suppression effect analysis
Abstract: A smoke extractor is the exit where the smoke that are toxic gas and high temperature gas goes out during a fire. The height and position and exhaust velocity of a smoke extractor have crucial influences on the smoke extraction effect. In this paper, By using the method of numerical simulation in FDS, and analyzing the smoke extraction effect influenced by the change of the height and velocity and position of a smoke extraction, the results have been obtained that with the increasing of the height of a smoke extractor, the smoke extraction effect will be improved in any exhaust velocity. When the exhaust velocity in a smoke extractor is increased gradually, the change of the height of a smoke extractor has bigger influence on the smoke overflow thickness, while a large exhaust velocity has better effect than small exhaust velocity on smoke control. A side extraction doesn’t work as well as a top extraction, and extraction at the far wall is better than at the near. However, the mechanical smoke exhaust velocity should be kept moderate, far too great velocity is likely to lead to the disorder of the smoke layer. On the other hand, if the flow of the smoke layer is too small, the exhaust efficiency would be too low. Building exhausts system exhaust the heat flue gas, but also hot flue gas that are used to actuate the automatic sprinkler system will be discharge. Therefore, actuating the exhaust system may affect the normal actuating automatic sprinkler system. In this paper, Using FDS to simulate the smoke exhaust system and automatic sprinkler system coexist, in order to provide theoretical guidance by study on a smoke extractor designs influence on sprinkler systems.
Key words: height of smoke extractor； layout of smoke extractor；smoke extraction effect；sprinkler systems； RTI；FDS
目录
第一章 绪论 1
1.1 背景和目的意义 1
1.1.1 建筑物火灾现状和特点 1
1.1.2 研究目的和意义 1
1.2 国内外研究现状 2
1.2.1 国外研究现状 2
1.2.2 国内研究现状 3
1.3 本文研究内容和技术线路 3
1.3.1 本课题的研究内容 3
1.3.2 本课题研究的技术路线 4
第二章 火灾烟气理论和烟气基本蔓延特性 6
2.1 火灾动力学理论基础 6
1.1.1 火灾发生的机理 6
2.1.1 火灾发展的基本过程 7