發(fā)布時間：2018-03-16 23:13

  本文選題：城市地下道路　切入點：坡度　出處：《北京工業(yè)大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：城市地下道路日益成為城市道路的重要組成部分,并且在城市地下道路的建設(shè)中,一些特殊的結(jié)構(gòu)形式(岔路、坡道、彎道)越來越頻繁的出現(xiàn)。由于城市地下道路內(nèi)部的結(jié)構(gòu)具有岔路多、彎道多、坡度大等特點,使得其發(fā)生火災(zāi)時,隧道內(nèi)的煙氣流動更加復(fù)雜,而目前關(guān)于具有這些異形斷面的城市地下道路的煙氣流動特性的研究較少。基于此,本文通過數(shù)值模擬和試驗研究相結(jié)合的手段對平直隧道、坡度隧道及曲線隧道內(nèi)煙氣的擴散特及控制技術(shù)進(jìn)行了研究,以便于確定有效的通風(fēng)及人員安全疏散方案。首先采用數(shù)值模擬軟件FDS,通過對不同長度的模型和邊界是否外擴進(jìn)行了模擬研究,給出了數(shù)值模擬中所建模型的最佳長度和合理邊界條件。在此基礎(chǔ)上建立了平直隧道模型,對不同火源功率及隧道寬度的平直隧道進(jìn)行模擬,得到不同工況下的煙氣卷吸量沿隧道縱向的分布規(guī)律,以便為集中排煙系統(tǒng)排煙量的確定提供參考。針對坡度隧道,通過數(shù)值模擬對隧道的坡度和火源功率對煙氣擴散特性的影響進(jìn)行了研究,得到了煙氣溫度及速度的沿隧道縱向的分布規(guī)律,并對其中的溫度分布規(guī)律進(jìn)行了試驗驗證。然后運用數(shù)值模擬和比例模型試驗的研究手段,對坡度隧道在不同坡度和火源功率下的臨界風(fēng)速進(jìn)行了確定,并用得到的風(fēng)速值擬合出坡度隧道臨界風(fēng)速修正公式kg=1+0.0715i。最后對曲線隧道內(nèi)煙氣的擴散特性及縱向煙氣控制進(jìn)行了數(shù)值模擬研究。通過改變曲線隧道的半徑和弧度及火源功率來研究這些因素對煙氣蔓延及控制的影響。結(jié)果表明:曲線隧道弧度的改變比半徑的改變對于煙氣蔓延和控制的影響大。
[Abstract]:Urban underground roads are increasingly becoming an important part of urban roads, and in the construction of urban underground roads, some special structural forms (fork roads, ramps, etc.). Because the structure of the underground road in the city has more and more bifurcations, more bends and large slopes, the flue gas flow in the tunnel becomes more complicated when the fire occurs. However, there are few studies on the flue gas flow characteristics of urban underground roads with these special-shaped sections. The diffusion characteristics and control techniques of flue gas in slope tunnel and curve tunnel are studied. In order to determine the effective ventilation and safety evacuation scheme, the numerical simulation software FDS is used to simulate the model and boundary extension of different lengths. The optimum length and reasonable boundary conditions of the model in numerical simulation are given. On the basis of the model, the model of straight tunnel with different fire source power and tunnel width is established, and the model is used to simulate the straight tunnel with different fire source power and tunnel width. The distribution of flue gas entrainment along the tunnel under different working conditions is obtained in order to provide a reference for the determination of the exhaust volume of the centralized exhaust system. The influence of the slope of tunnel and the power of fire source on the characteristics of flue gas diffusion is studied by numerical simulation. The distribution law of flue gas temperature and velocity along the longitudinal direction of tunnel is obtained. Then the critical wind speed of slope tunnel under different slope and fire source power is determined by means of numerical simulation and proportional model test. The critical wind speed correction formula kg=1 0.0715i. finally, numerical simulation of smoke diffusion characteristics and longitudinal flue gas control in curved tunnel is carried out. The radius and arc of curved tunnel are changed. The influence of these factors on flue gas spread and control is studied. The results show that the change of curve tunnel arc is more important than the change of radius on smoke spread and control.
【學(xué)位授予單位】：北京工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：U492.8

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 閆治國,楊其新;秦嶺特長公路隧道火災(zāi)溫度場分布試驗研究[J];地下空間;2003年02期

，

本文編號：1622097