【摘要】：隨著我國交通行業(yè)的快速發(fā)展,已建成公路隧道數(shù)量和長度均日益增大,我國已步入世界上隧道數(shù)量最多、地形工況最復(fù)雜、發(fā)展速度最快的國家行列。與此同時,高昂的隧道運營、維護(hù)費用以及不斷出現(xiàn)的隧道事故,愈發(fā)引起了國內(nèi)外研究人員對隧道通風(fēng)問題的關(guān)注。研究表明,公路隧道機(jī)械通風(fēng)所需的費用與隧道長度的三次方成正比,因此如何選用合適的隧道通風(fēng)方式顯得尤為重要。由于公路隧道修建時考慮地質(zhì)地貌等方面的因素,公路隧道往往具有一定的坡度,而車輛在上下坡行駛時排放的污染物濃度的不同導(dǎo)致了雙洞隧道中左右線需風(fēng)量的差異。針對這種情況,國內(nèi)外學(xué)者提出的空氣互換式通風(fēng)理論開始逐漸應(yīng)用于新修建的雙洞單向公路隧道。本文基于國內(nèi)外關(guān)于互補(bǔ)式通風(fēng)系統(tǒng)的研究現(xiàn)狀,依托福建廈門某隧道為原型,主要展開來以下方面的研究。理論計算方面,本文通過對中遠(yuǎn)期車流量的預(yù)測及需風(fēng)量的計算得出了該隧道通風(fēng)設(shè)計的方案,論證了互補(bǔ)式通風(fēng)系統(tǒng)在公路隧道通風(fēng)中的適用性。研究表明:在中遠(yuǎn)期通過控制右線隧道行車速度在60~80km/h,左線行車速度在100 km/h時,僅依靠自然風(fēng)和車輛交通風(fēng)配合互補(bǔ)式通風(fēng)網(wǎng)絡(luò)即可滿足隧道正常工況下的運營通風(fēng)要求。物理模型試驗方面,基于相似理論搭建的隧道物理試驗?zāi)Ｐ?在隧道口設(shè)置射流風(fēng)機(jī)來模擬車輛行駛的交通風(fēng),測試了正常工況下不同位置處斷面的速度場分布情況;并通過模型隧道內(nèi)油盤燃燒試驗來測試了隧道內(nèi)火災(zāi)工況下煙氣濃度場分布情況,對模型試驗的結(jié)果以及誤差產(chǎn)生的原因進(jìn)行了分析說明;模型試驗結(jié)論對比驗證了隧道通風(fēng)研究中采用CFD數(shù)值模擬方法的可行性。數(shù)值模擬方面,運用FLUENT數(shù)值模擬軟件建立了公路隧道通風(fēng)三維數(shù)值模型,主要模擬了正常工況下橫通道數(shù)量對隧道內(nèi)空氣流速的影響,同時基于車輛排放污染物設(shè)置了“點源”模型并以CO濃度為參考模擬了隧道內(nèi)污染物的分布情況;通過建立火災(zāi)燃燒模型,在火災(zāi)工況下設(shè)定固定火災(zāi)熱釋放率研究了橫通道開閉工況下對煙氣濃度場和溫度場分布情況的影響。通過對模擬結(jié)果的分析研究,主要得出了以下結(jié)論:1)正常工況下橫通道數(shù)量并不是越多越好,增設(shè)的橫通道對隧道內(nèi)氣體流速沒有明顯改變,對互補(bǔ)式通風(fēng)系統(tǒng)的換氣作用不明顯。同時由于中間增設(shè)的橫通道內(nèi)部氣流速度過慢而導(dǎo)致了CO濃度過高的問題,不利于橫通道內(nèi)人員和車輛的活動。2)火災(zāi)工況下橫通道的開閉對隧道內(nèi)煙氣濃度場和溫度場的影響較為明顯,當(dāng)橫通道開啟時左線隧道行車的活塞風(fēng)通過橫通道進(jìn)入右線隧道內(nèi),增大了煙氣擴(kuò)散的速率,減小了隧道內(nèi)煙氣濃度質(zhì)量百分比。同時,橫通道開啟后隧道中人員活動區(qū)域的溫度明顯降低,溫度較高的近火源處穩(wěn)定在400K以下。綜合考慮,發(fā)生火災(zāi)時保持橫通道的開啟,極大地提升了人員逃生的幾率,有利于滅火救援工作的開展。
[Abstract]:With the rapid development of the traffic industry in our country, the number and the length of the constructed highway tunnel are increasing, and our country has entered the world with the largest number of tunnels, the most complex terrain conditions and the fastest growing speed. At the same time, the high tunnel operation, maintenance cost and the ongoing tunnel accident have become more and more attention to the problem of tunnel ventilation at home and abroad. The research shows that the cost of the mechanical ventilation of the highway tunnel is directly proportional to the third power of the tunnel length, so how to select the proper ventilation mode of the tunnel is particularly important. The road tunnel often has a certain slope due to the factors such as the geological and geomorphic features in the construction of the highway tunnel, and the difference of the air volume required by the left and right lines in the double-hole tunnel is caused by the difference in the concentration of the pollutants discharged when the vehicle is running downhill. In view of this situation, the air-exchange ventilation theory proposed by scholars at home and abroad is gradually applied to the newly built two-hole one-way road tunnel. Based on the research status of the complementary ventilation system at home and abroad, this paper mainly studies the following aspects based on the prototype of a certain tunnel in Xiamen. In the aspect of theoretical calculation, the scheme of the ventilation design of the tunnel is obtained by the calculation of the forecast of the medium and long-term traffic flow and the calculation of the required air volume, and the applicability of the complementary ventilation system in the ventilation of the highway tunnel is demonstrated. The results show that the running speed of the right-line tunnel is controlled to be 60-80km/ h and the running speed of the left line is 100 km/ h by controlling the driving speed of the right-line tunnel, and the operation and ventilation requirements under the normal working conditions of the tunnel can be satisfied only by the natural wind and the vehicle traffic wind and the complementary ventilation network. In the aspect of physical model test, a tunnel physical test model is set up based on the similarity theory, a jet fan is arranged at the tunnel junction to simulate the traffic wind of the vehicle, and the velocity field distribution of the cross section at different positions under normal working conditions is tested; In this paper, the distribution of the smoke concentration field in the tunnel is tested through the combustion test of the oil pan in the tunnel, and the results of the model test and the cause of the error are analyzed. The results of the model test show the feasibility of using the CFD numerical simulation method in the tunnel ventilation research. in that aspect of numerical simulation, a three-dimensional numerical model of highway tunnel ventilation is set up by using the FLUENT numerical simulation software, which mainly simulate the influence of the number of transverse channels in the normal working condition on the air flow rate in the tunnel, meanwhile, the 鈥減oint source鈥，

本文編號：2345078