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排烟效率是衡量集中排烟火灾通风方案排烟效果的重要指标。为合理分析排烟效率的变化特性,结合某隧道集中排烟系统设计,借助CFD技术,对设置有排烟道的隧道进行了火灾烟气控制的模拟分析,研究了排烟阀开启个数、开口面积和设置间距对双向排烟和单向排烟两种集中排烟模式下不同排烟阀设置方案中总排烟效率和各个排烟阀的排烟效率的影响。结果表明,集中排烟模式可有效将火灾烟气排出隧道。当排烟阀对称开启时,双向排烟模式下,减少排烟阀开启个数,单个排烟阀的排烟效率升高,但总排烟效率降低;当开口面积较小时,增大面积,总排烟效率升高明显,继续增大开口面积时总排烟效率升高效果减弱;增大间距有利于隧道排烟。单向排烟模式下,当排烟阀开启个数较多或开口面积较大时,距离风机最远的排烟阀排烟效率降低,并出现烟流流出排烟道的现象,排烟阀失效,可考虑在非排烟侧开启少量排烟阀,增大间距,使总排烟效率升高。
Exhaust efficiency is a measure of smoke exhaust ventilation program focused on the effectiveness of smoke. In order to analyze the variation characteristics of smoke evacuation efficiency reasonably and combine with the design of a smoke evacuation system of a certain tunnel, the fire flue gas control of tunnel with smoke evacuation was simulated by CFD technology. The number of opening of smoke evacuation valve, The influence of opening area and spacing on the total smoke exhaust efficiency and the smoke exhaust efficiency of each smoke exhaust valve in two different exhaust valve modes of two-way smoke exhaust and one-way smoke exhaust were studied. The results show that the centralized smoke extraction mode can effectively remove the fire smoke from the tunnel. When the exhaust valve symmetrical open, the two-way exhaust mode, reducing the number of exhaust valve open, a single exhaust valve exhaust smoke efficiency increases, but the total smoke exhaust efficiency decreases; when the opening area is small, increasing the area, The total efficiency of the smoke evidently increased. When the opening area was continuously increased, the efficiency of the total smoke evacuation was weakened. Increasing the space was beneficial to the tunnel smoke evacuation. In the one-way exhaust mode, when the exhaust valve opens more or the opening area is larger, the exhaust efficiency of the exhaust valve farthest from the fan decreases, and the phenomenon that the smoke flows out of the exhaust duct appears. The exhaust valve Failure, consider opening a small amount of exhaust valve in the non-smoke side, increasing the spacing, so that the total efficiency of the smoke.