本文關鍵詞： 模擬研究 半敞開式隧道 隧道火災 溫度場 煙氣逆流層　出處：《安徽理工大學》2015年碩士論文　論文類型：學位論文

【摘要】：近年來,隨著我國社會的進步和交通運輸事業(yè)的迅速發(fā)展,各種城市隧道迅速涌現(xiàn)。隧道給人們的日常生活和交通出行帶來了很多方便,也帶來了一系列消防安全問題。由于隧道空間密閉且狹長,隧道內(nèi)一旦發(fā)生火災,可燃物燃燒產(chǎn)生的大量高溫有毒有害氣體在有限空間內(nèi)迅速蔓延,通常會造成多數(shù)人員傷亡的重大安全事故。隧道內(nèi)發(fā)生火災時,人員一般會逆著風流逃生且消防救援人員通常會從火源上游下行,執(zhí)行滅火救援工作。因此,研究隧道火災火源上游溫度場分布規(guī)律及煙氣逆流特性對隧道火災滅火救援工作具有一定的理論指導意義。 本文在前人現(xiàn)場試驗研究的基礎上,利用數(shù)值模擬的方法以不同的網(wǎng)格尺寸對原工況進行模擬,將模擬結果與試驗結果對比分析,確定了合理的網(wǎng)格尺寸并驗證了數(shù)值模擬方法的可行性。然后,通過改變原工況中火源位置及高度參數(shù),并對不同火源位置及火源高度工況條件進行模擬,最后,對不同工況條件下半敞開式隧道火災火源上游頂棚溫度場分布規(guī)律及煙氣逆流特性進行對比分析。 總結得出：第一,火源上游頂棚處溫度分布沿縱向呈衰減趨勢且火源越高溫度衰減速度越快,貼壁火源上游頂棚溫度沿縱向衰減速度大于中央火源。中央火源上游頂棚處溫度橫向分布由中間向兩側逐漸降低且火源面越高溫度衰減梯度越大,但在離火源縱向近距離范圍內(nèi)出現(xiàn)相反的分布規(guī)律。在離火源縱向水平垂直近距離范圍內(nèi),貼壁火源頂棚處溫度在橫向上呈傾斜和反向傾斜分布；在半敞開口段范圍內(nèi),火源上游頂棚溫度出現(xiàn)小范圍的波動。第二,中央火源上方煙氣逆流層的長度大于貼壁火源,火源高度增加煙氣逆流層長度減小且中央火源上游煙氣層高度低于貼壁火源。第三,在不同火源位置條件下,中央火源頂棚溫度呈現(xiàn)倒立浴盆區(qū)和低溫區(qū)的范圍大于貼壁火源,中央火源上游煙氣逆流層過渡區(qū)的范圍小于貼壁火源,而穩(wěn)定區(qū)和極不穩(wěn)定區(qū)范圍大于貼壁火源。在不同火源高度條件下,火源高度增加頂棚溫度呈現(xiàn)凸型區(qū)、倒立浴盆區(qū)及低溫區(qū)范圍不斷縮小,而凹形區(qū)隨之擴大,同時煙氣層過渡區(qū)和極不穩(wěn)定區(qū)范圍擴大,穩(wěn)定區(qū)范圍隨之縮小。以上結論為隧道火災消防安全設計提供了一定的理論依據(jù)。
[Abstract]:In recent years, with the progress of our society and the rapid development of transportation, a variety of urban tunnels have emerged rapidly. Tunnels have brought a lot of convenience to people's daily life and transportation. It also brings a series of fire safety problems. Because the tunnel space is closed and narrow, once there is a fire in the tunnel, a large number of high temperature toxic and harmful gases produced by combustible combustion spread rapidly in the limited space. When there is a fire in the tunnel, the personnel usually escape from the wind flow and the fire rescue personnel usually go down from the upstream of the fire source to carry out the fire fighting and rescue work. The research on the distribution of temperature field in the upper reaches of tunnel fire source and the characteristics of flue gas countercurrent have certain theoretical guiding significance for tunnel fire extinguishing and rescue work. In this paper, based on the previous field experiments, the numerical simulation method is used to simulate the original working conditions with different mesh sizes, and the simulation results are compared with the experimental results. The reasonable mesh size is determined and the feasibility of the numerical simulation method is verified. Then, by changing the location and height parameters of the fire source in the original working condition, the different fire source location and the working conditions of the fire source height are simulated. Finally, the temperature field distribution and smoke countercurrent characteristics in the upper reaches of the fire source of semi-open tunnel fire are compared and analyzed under different working conditions. The conclusions are as follows: first, the temperature distribution of the roof in the upstream of the fire source is attenuated along the longitudinal direction and the higher the fire source is, the faster the temperature attenuation rate is. The vertical attenuation rate of the roof temperature in the upstream of the central fire source is higher than that of the central fire source. The transverse temperature distribution of the roof in the upper reaches of the central fire source gradually decreases from the middle to the two sides and the higher the temperature attenuation gradient is the greater the temperature attenuation gradient is. In the vertical vertical and close range from the fire source, the temperature at the roof of the wall fire source is tilted laterally and tilted in the opposite direction. In the range of semi-open mouth, there is a small fluctuation of ceiling temperature in the upper reaches of the fire source. Second, the length of flue gas countercurrent layer above the central fire source is larger than that of the adherent fire source. The length of flue gas countercurrent layer decreases with the increase of fire source height and the height of upstream flue gas layer of central fire source is lower than that of wall fire source. Thirdly, under different fire source location conditions. The ceiling temperature of the central fire source is larger than that of the adherent fire source in the inverted bath area and the low temperature zone, and the range of the upstream flue gas countercurrent layer transition area is smaller than that of the adherent fire source. The range of stable and extremely unstable region is larger than that of adherent fire source. Under the condition of different fire source height, the roof temperature of fire source height increases in convex region, and the area of inverted bathtub and low temperature area is continuously reduced. The concave zone is enlarged, and the range of transition zone and extremely unstable zone of flue gas layer is enlarged, and the range of stable zone is reduced. The above conclusion provides a certain theoretical basis for the fire safety design of tunnel fire.
【學位授予單位】：安徽理工大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：U458

【參考文獻】

相關期刊論文 前10條

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

2 王明年,楊其新,袁雪戡,楊忠;公路隧道火災溫度場的分布規(guī)律研究[J];地下空間;2003年03期

3 閆治國;楊其新;朱合華;;長大公路隧道火災溫度場分布試驗研究[J];東南大學學報(自然科學版);2005年S1期

4 趙望達;李洪;徐志勝;姜學鵬;;鐵路隧道火災中煙氣逆流層長度的研究[J];防災減災工程學報;2010年03期

5 郭春;岳亭龍;王明年;;公路隧道火災中火區(qū)火風壓研究[J];遼寧工程技術大學學報(自然科學版);2008年S1期

6 肖榮華;;高速公路隧道火災[J];防災博覽;2005年06期

7 李元洲,霍然,易亮,史聰靈,周允基;隧道火災煙氣發(fā)展的模擬計算研究[J];中國工程科學;2004年02期

8 王軍;張旭;;公路隧道火災煙氣沿程溫度分布的合理確定[J];公路隧道;2009年03期

9 韓常領;趙永國;;東西高速公路隧道火災逃生模擬分析[J];中外公路;2009年04期

10 楊其新,閻治國;秦嶺終南山特長公路隧道火災模型試驗研究[J];廣西交通科技;2003年03期

，

本文編號：1449392