本文選題：隧道火災(zāi)　切入點(diǎn)：煙氣熱分層　出處：《中國科學(xué)技術(shù)大學(xué)》2017年碩士論文

【摘要】：在我國經(jīng)濟(jì)飛速發(fā)展的大環(huán)境下,城市化進(jìn)程正平穩(wěn)有序地進(jìn)行,為了降低區(qū)域人口增長帶來的交通壓力,地下空間的開發(fā)使用便成為城市發(fā)展的重要方向。近幾年來,全國各城市修建大量城市公路隧道以及地鐵隧道,為人們的交通出行帶來極大便利。但隨之而來的是,城市中各種隧道存在的火災(zāi)隱患以及已經(jīng)出現(xiàn)的火災(zāi)事故給隧道消防工作的開展帶來了巨大挑戰(zhàn)。在火災(zāi)事故中,因吸入煙氣窒息死亡的人數(shù)比例達(dá)到85%,對(duì)于隧道火災(zāi),煙氣運(yùn)動(dòng)規(guī)律研究以及高效排煙模式的選擇對(duì)降低火災(zāi)事故損失、救援工作的開展具有重要意義。盡管前人已在此方面進(jìn)行研究,但隧道中縱向風(fēng)作為一重要邊界條件,在其影響下的煙氣運(yùn)動(dòng)規(guī)律,豎井區(qū)域流場(chǎng)、溫度場(chǎng)結(jié)構(gòu),豎井排煙效率與無通風(fēng)時(shí)有很大不同。因此本文通過進(jìn)行理論分析,開展小尺寸實(shí)驗(yàn)以及全尺寸模擬實(shí)驗(yàn),研究在縱向通風(fēng)影響下的隧道火災(zāi)煙氣熱分層以及不同邊界條件對(duì)豎井排煙的作用規(guī)律,主要內(nèi)容為以下幾個(gè)方面:1、煙氣熱分層及其判定方法對(duì)比。通過開展理論分析以及小尺寸實(shí)驗(yàn),對(duì)隧道火災(zāi)中煙氣在不同風(fēng)速影響下的熱分層現(xiàn)象及其變化規(guī)律、結(jié)構(gòu)特點(diǎn)進(jìn)行研究:對(duì)于5.73 kW火源,縱向通風(fēng)風(fēng)速達(dá)到0.0961m/s時(shí)煙氣層穩(wěn)定性開始被破壞,在風(fēng)速超過0.226 m/s時(shí)完全紊亂。隧道火災(zāi)煙氣層界面高度在縱向通風(fēng)影響下為下降再升高,2.30 kW、5.74 kW、9.18 kW三種火源功率,其風(fēng)速拐點(diǎn)分別為0.485 m/s、0.629 m/s、0.629 m/s。對(duì)不同熱層判定方法結(jié)論進(jìn)行對(duì)比分析:對(duì)于N系數(shù)法,建議N取值為30;低風(fēng)速下可考慮無量綱溫度法;浮力頻率法判定結(jié)果偏低。2、對(duì)縱向通風(fēng)影響下的豎井排煙煙氣卷吸情況進(jìn)行分析,采用小尺度實(shí)驗(yàn)研究縱向通風(fēng)對(duì)隧道豎井區(qū)域煙氣流場(chǎng)結(jié)構(gòu)以及吸穿現(xiàn)象的影響規(guī)律。對(duì)于低高度豎井或縱向通風(fēng)較大的工況,會(huì)出現(xiàn)外界冷空氣自豎井頂部卷吸進(jìn)入豎井內(nèi)部的現(xiàn)象,影響煙氣排出。在吸穿臨界條件的判定中,無量綱數(shù)Fcritical=1.5在無風(fēng)條件下尚可適用,但在縱向通風(fēng)條件下不再適用,而Ricritical1.4則不受通風(fēng)影響。3、通過開展數(shù)值模擬,對(duì)縱向通風(fēng)、豎井高度、豎井排列方式影響下的豎井排煙效率、豎井內(nèi)部流場(chǎng)及溫度場(chǎng)分布情況進(jìn)行研究:小于3m的豎井排煙量隨著縱向通風(fēng)的增加而降低;當(dāng)豎井高度超過3m時(shí),豎井排煙量隨著縱向通風(fēng)的增加先上升后降低,排煙量在風(fēng)速為1.5～2 m/s時(shí)達(dá)到最大值。在無縱向通風(fēng)條件下,新布置方式對(duì)吸穿現(xiàn)象的抑制作用明顯,但當(dāng)豎井在縱向風(fēng)作用下達(dá)到最大排煙量時(shí),布置方式對(duì)豎井的排煙量的提升有限。
[Abstract]:In order to reduce the traffic pressure brought by regional population growth, the development and use of underground space has become an important direction of urban development.In recent years, a large number of urban road tunnels and subway tunnels have been built in cities of China, which bring great convenience to people's transportation.However, fire hazards and fire accidents in various tunnels in cities have brought great challenges to the development of tunnel fire protection work.In the fire accident, the proportion of death caused by smoke inhalation asphyxiation reached 85. For tunnel fire, the study of smoke movement law and the choice of efficient smoke exhaust mode are of great significance to reduce the loss of fire accident and carry out rescue work.Although the previous researches have been carried out in this field, the vertical wind in tunnel is an important boundary condition, under its influence, the smoke movement law, the flow field in the shaft area, the structure of temperature field, the efficiency of exhaust smoke in the shaft are very different from those in the absence of ventilation.Therefore, through theoretical analysis, small scale experiments and full-scale simulation experiments, the thermal stratification of flue gas in tunnel fires under the influence of longitudinal ventilation and the effect of different boundary conditions on the exhaust smoke of vertical wells are studied in this paper.The main contents are as follows: 1, comparison of flue gas thermal stratification and its judging methods.Through theoretical analysis and small scale experiments, the thermal stratification phenomenon and its variation law of flue gas in tunnel fire under the influence of different wind speed are studied. The structural characteristics are as follows: for 5.73 kW fire source,The stability of the flue gas layer begins to be destroyed when the longitudinal ventilation wind speed reaches 0.0961m/s and is completely disturbed when the wind speed exceeds 0.226 m / s.Under the influence of longitudinal ventilation, the interface height of smoke layer of tunnel fire is decreased and then increased by 2.30 kW 5.74 kW / 9.18 kW, and the inflection point of wind velocity is 0.485 m / s ~ 0. 629 m / s / s ~ 0. 629 m / s respectively.The conclusions of different thermosphere determination methods are compared and analyzed: for the N coefficient method, the value of N is suggested to be 30, and the dimensionless temperature method can be considered at low wind speed.The method of buoyancy frequency is low. 2. The smoke entrainment of vertical shaft under the influence of longitudinal ventilation is analyzed. The influence of longitudinal ventilation on the structure of flue gas flow field and the phenomenon of suction in tunnel shaft is studied by small scale experiment.For low height shaft or large longitudinal ventilation conditions, the phenomenon of external cold air entrainment from the top of the shaft into the shaft interior will affect the flue gas discharge.In determining the critical condition of suction, the dimensionless Fcritical=1.5 can be applied under the condition of no wind, but not in the condition of longitudinal ventilation, while Ricritical1.4 is not affected by ventilation.The distribution of flow field and temperature field in the vertical shaft under the influence of the vertical well arrangement mode is studied: the smoke discharge quantity of the shaft with the increase of vertical ventilation decreases with the increase of vertical ventilation, and when the height of the shaft is more than 3m, the distribution of the flow field and the temperature field in the shaft is studied: when the height of the shaft is more than 3m,With the increase of vertical ventilation, the exhaust volume of the shaft first rises and then decreases, and the exhaust volume reaches the maximum when the wind speed is 1.5 ~ 2 m / s.Under the condition of no longitudinal ventilation, the new arrangement can restrain the phenomenon of suction obviously, but when the shaft reaches the maximum amount of exhaust smoke under the action of longitudinal wind, the way of layout has a limited effect on the increase of the exhaust volume of the shaft.
【學(xué)位授予單位】：中國科學(xué)技術(shù)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：U453.5;U458

【參考文獻(xiàn)】

中國期刊全文數(shù)據(jù)庫 前10條

1 邱永海;樓波;許建紅;龍新峰;;火源與排煙口布置對(duì)隧道火災(zāi)排煙影響的數(shù)值模擬[J];安全與環(huán)境學(xué)報(bào);2016年03期

2 姜學(xué)鵬;袁月明;李旭;;隧道集中排煙速率對(duì)排煙口下方煙氣層吸穿現(xiàn)象的影響[J];安全與環(huán)境學(xué)報(bào);2014年02期

3 陽東;祝實(shí);霍然;胡隆華;;受限空間內(nèi)水平風(fēng)作用下熱分層流流場(chǎng)結(jié)構(gòu)的POD分析[J];重慶大學(xué)學(xué)報(bào);2013年01期

4 韓見云;紀(jì)杰;王培永;;豎井橫截面積對(duì)隧道自然排煙效果影響的實(shí)驗(yàn)研究[J];火災(zāi)科學(xué);2013年01期

5 陽東;胡隆華;霍然;蔣亞強(qiáng);劉帥;祝實(shí);;縱向風(fēng)對(duì)通道火災(zāi)煙氣豎向分層特性的影響[J];燃燒科學(xué)與技術(shù);2010年03期

6 何開遠(yuǎn);樊洪明;趙耀華;王峰;;島側(cè)地鐵站臺(tái)火災(zāi)煙氣運(yùn)動(dòng)的數(shù)值模擬[J];工程熱物理學(xué)報(bào);2010年02期

7 黃玉良;茅靳豐;李偉華;姚亦君;;城市隧道自然通風(fēng)經(jīng)濟(jì)性研究[J];建筑熱能通風(fēng)空調(diào);2008年05期

8 傅德明;張冠軍;;我國矩形掘進(jìn)機(jī)隧道施工技術(shù)發(fā)展與應(yīng)用[J];上海建設(shè)科技;2008年02期

9 杜寶玲;;國外地鐵火災(zāi)事故案例統(tǒng)計(jì)分析[J];消防科學(xué)與技術(shù);2007年02期

10 胡隆華;霍然;王浩波;楊瑞新;;公路隧道內(nèi)火災(zāi)煙氣溫度及層化高度分布特征試驗(yàn)[J];中國公路學(xué)報(bào);2006年06期

中國博士學(xué)位論文全文數(shù)據(jù)庫 前6條

1 高子鶴;隧道內(nèi)受限火羽流行為特征及豎井自然排煙機(jī)理研究[D];中國科學(xué)技術(shù)大學(xué);2016年

2 范傳剛;隧道火災(zāi)發(fā)展特性及豎井自然排煙方法研究[D];中國科學(xué)技術(shù)大學(xué);2015年

3 許秦坤;狹長通道火災(zāi)煙氣熱分層及運(yùn)動(dòng)機(jī)制研究[D];中國科學(xué)技術(shù)大學(xué);2012年

4 涂然;高原低壓低氧對(duì)池火燃燒與火焰圖像特征的影響機(jī)制[D];中國科學(xué)技術(shù)大學(xué);2012年

5 陽東;狹長受限空間火災(zāi)煙氣分層與卷吸特性研究[D];中國科學(xué)技術(shù)大學(xué);2010年

6 胡隆華;隧道火災(zāi)煙氣蔓延的熱物理特性研究[D];中國科學(xué)技術(shù)大學(xué);2006年

中國碩士學(xué)位論文全文數(shù)據(jù)庫 前3條

1 袁月明;集中排煙模式下隧道煙氣層吸穿現(xiàn)象研究[D];中南大學(xué);2014年

2 蔡加發(fā);公路隧道火災(zāi)分析及救災(zāi)預(yù)案研究[D];重慶交通大學(xué);2008年

3 陶雙江;豎井對(duì)長大公路隧道火災(zāi)影響的模型試驗(yàn)研究[D];西南交通大學(xué);2004年

，

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