横通道对公路隧道互补式通风的影响数值模拟及试验研究
发布时间：2018-11-20 13:46
【摘要】：随着我国交通行业的快速发展,已建成公路隧道数量和长度均日益增大,我国已步入世界上隧道数量最多、地形工况最复杂、发展速度最快的国家行列。与此同时,高昂的隧道运营、维护费用以及不断出现的隧道事故,愈发引起了国内外研究人员对隧道通风问题的关注。研究表明,公路隧道机械通风所需的费用与隧道长度的三次方成正比,因此如何选用合适的隧道通风方式显得尤为重要。由于公路隧道修建时考虑地质地貌等方面的因素,公路隧道往往具有一定的坡度,而车辆在上下坡行驶时排放的污染物浓度的不同导致了双洞隧道中左右线需风量的差异。针对这种情况,国内外学者提出的空气互换式通风理论开始逐渐应用于新修建的双洞单向公路隧道。本文基于国内外关于互补式通风系统的研究现状,依托福建厦门某隧道为原型,主要展开来以下方面的研究。理论计算方面,本文通过对中远期车流量的预测及需风量的计算得出了该隧道通风设计的方案,论证了互补式通风系统在公路隧道通风中的适用性。研究表明:在中远期通过控制右线隧道行车速度在60~80km/h,左线行车速度在100 km/h时,仅依靠自然风和车辆交通风配合互补式通风网络即可满足隧道正常工况下的运营通风要求。物理模型试验方面,基于相似理论搭建的隧道物理试验模型,在隧道口设置射流风机来模拟车辆行驶的交通风,测试了正常工况下不同位置处断面的速度场分布情况;并通过模型隧道内油盘燃烧试验来测试了隧道内火灾工况下烟气浓度场分布情况,对模型试验的结果以及误差产生的原因进行了分析说明;模型试验结论对比验证了隧道通风研究中采用CFD数值模拟方法的可行性。数值模拟方面,运用FLUENT数值模拟软件建立了公路隧道通风三维数值模型,主要模拟了正常工况下横通道数量对隧道内空气流速的影响,同时基于车辆排放污染物设置了“点源”模型并以CO浓度为参考模拟了隧道内污染物的分布情况;通过建立火灾燃烧模型,在火灾工况下设定固定火灾热释放率研究了横通道开闭工况下对烟气浓度场和温度场分布情况的影响。通过对模拟结果的分析研究,主要得出了以下结论:1)正常工况下横通道数量并不是越多越好,增设的横通道对隧道内气体流速没有明显改变,对互补式通风系统的换气作用不明显。同时由于中间增设的横通道内部气流速度过慢而导致了CO浓度过高的问题,不利于横通道内人员和车辆的活动。2)火灾工况下横通道的开闭对隧道内烟气浓度场和温度场的影响较为明显,当横通道开启时左线隧道行车的活塞风通过横通道进入右线隧道内,增大了烟气扩散的速率,减小了隧道内烟气浓度质量百分比。同时,横通道开启后隧道中人员活动区域的温度明显降低,温度较高的近火源处稳定在400K以下。综合考虑,发生火灾时保持横通道的开启,极大地提升了人员逃生的几率,有利于灭火救援工作的开展。
[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，
本文编号：2345078
[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，
本文编号：2345078
本文链接：https://www.wllwen.com/kejilunwen/daoluqiaoliang/2345078.html
