【作者】 张光鹏；

【导师】 雷波；

【作者基本信息】 西南交通大学 ， 供热、供燃气、通风及空调工程， 2008， 博士

【摘要】 随着公路隧道建设的不断发展,众多长大、复杂化的公路隧道不断地涌现出来,隧道通风及其控制系统的难度也随之增加。本文依托国家重点工程项目——锦屏施工辅助隧道对双洞单向特长公路隧道纵向通风技术进行了全面、详细地研究,编制了相应的公路隧道通风计算程序,并进行了隧道通风模型试验研究。当隧道内车流量较小、单车污染物排放较大时线源模型不能真实、准确反映隧道污染物分布的问题,提出采用“点源模型”来研究隧道运营通风中污染物的分布,并建立了单线公路隧道运营通风数值计算模型。依据网络通风及隧道火灾理论,建立了公路隧道网络通风及火灾事故通风数值计算模型。导出了上述计算模型的具体求解方法,并利用MATLAB编制了公路隧道运营通风计算程序和公路隧道火灾事故通风计算程序。受地形及车流工况的影响,相邻上、下行隧道内通风负荷有较大差异,为提高隧道通风系统的经济效益,详细地研究了双向换气方法在通风负荷不均匀双洞单向公路隧道通风中的应用,给出了具体的设计过程及计算方法,并采用该方法对锦屏施工辅助隧道进行了简要的通风设计计算。时变的车流通过隧道时,为使得通风控制系统做出有效地控制,开启相应的风机台数,依据隧道通风控制理论及神经网络基础知识,构建了用于单线公路隧道及双向换气式隧道网络通风控制的神经网络在线控制模型,导出了该模型的具体设计过程,并编制了相应的隧道通风控制程序。锦屏施工辅助隧道的摩擦阻力特性属于大粗糙度、非均匀糙率的问题,紧急停车带处的气体流动复杂,通风气流的摩擦阻力和局部阻力将是流动阻力的主要组成部分。依据相似理论建立了摩擦阻力和局部阻力损失系数的模型试验平台,在不同Re下进行了三组阻力系数的试验,通过对比分析,A、B线隧道的摩擦阻力损失系数λ为0.04,B线隧道正向和反向ξ值分别为0.3491和0.3362;利用几何相似,运动和动力类似的模型原理建立的射流风机升压力模型试验平台,用以验证CFD计算模型及方法的正确性。对锦屏施工辅助隧道A、B线在正常交通、交通阻滞及堵塞时,隧道内风机在两种不同开启方式下进行了数值模拟计算,给出隧道内污染物浓度分布情况以及隧道内三个不同位置发生交通阻滞和交通堵塞时污染物浓度达到限制值的时间;通过对A、B线隧道内分别按不同风机布置方式时隧道内压力分布的计算分析,给出适合于该隧道通风的风机布置方式;利用隧道火灾事故计算模块,对大型载重车在A、B线隧道三个不同位置发生火灾的工况进行了计算,给出了两条隧道内空气温度、壁面温度和火灾烟雾的分布;此外,还计算了在此规模火灾下高温烟气对射流风机的烧毁情况,并根据计算结果给出一些建设性的意见。为了研究神经网络在线控制方法在公路隧道通风中的控制效果,利用隧道通风控制程序,对锦屏施工辅助隧道分别通过三种交通流模型时进行了计算分析。结果表明控制模型能够根据实际情况相应地修改控制策略,将风机开启台数控制在适当的范围内,保证了隧道内的污染物浓度不超过控制标准。设计的神经网络在线控制方法在对单向公路隧道及双向换气式隧道网络通风进行控制中,具有良好的适应性能。更多还原

【Abstract】 With rapid development of construction of road tunnels, there has being a large number of long and complicated road tunnels nowadays, and the design of tunnel ventilation and control system is increasingly difficult. Based on the Jinping construct-assistance tunnel, the paper detailedly researches on tunnel ventilation for super long road tunnels with twin tubes, programs the road tunnel ventilation system, and carried on experiments in a model tunnel.For road tunnels within small vehicle flux and large contamination per vehicle, "line-source vehicle model" cannot truly and accurately simulate the distribution of contamination in tunnels, it proposes the "point-source vehicle model", and founds the numerical simulation model for the ventilation of long road tunnels with twin tubes. Base on the theory of network ventilation and emergency ventilation in tunnel fires, it sets up the numerical simulation model for network ventilation and emergency ventilation, educes their specific solutions, and designs a program for normal and emergency ventilation in road tunnels.Due to terrain and vehicle density, the ventilation rates of twin tubes for fulfilling the requirement for temperature and pollution concentration is asymmetric. For saving the cost of ventilation system, it does detailed research on the application of air inter-exchange in load-asymmetric road tunnels, proposes the specific formulae and approaches, and uses the technique to simulate the ventilation system of Jinping construct-assistance tunnel.As the vehicle flux varies, the ventilation control system can be controlled efficiently by turning on or off a part of fans, respectively corresponding to increasing or decreasing vehicle flux. It establishes the neural network on-line control model for single-line road tunnel using bidirectional air inter-exchange ventilation system, including specific procedures and programs, based on the theory of tunnel ventilation network and of the neural network on-line control.The resistance characteristics of Jinping construct-assistance tunnel is large-coarseness and nonuniform-roughness. And air flow in emergency stop location is very complicated. The flow resistance is mostly made up of friction resistance and local resistance. According to similitude theory, it sets up the scale model test-bed for testing the friction resistance and the local resistance, and carried out experiments under different Reynold Number conditions. The friction resistance coefficient ,λ, both Tunnel A and Tunnel B, is 0.04. The positive and passive local resistance coefficients for tunnel B are respectively 0.349 and 0.336. Then set up another test-bed for testing the pressure rise of impulse fans, and confirm the correctness of CFD modeling and numerical method.It analyzes the distribution of pollution concentration in tunnels under normal traffic, blocked traffic and jam conditions, and simulates the time beyond the limited pollution concentration for both blocked traffic and jam. After simulating the distribution of pressure in both tunnel A and tunnel B with different collocation of fans, it proposes the proper collocation of fans for these tunnels. Then uses the fire module to simulate the fire scenario of heavy good vehicle (HGV) in three different places, presents the distribution of air temperature, wall temperature, and smoke concentration in both tunnel A and tunnel B. In addition, it simulates the impacts of high smoke temperature on the impulse fans, and proposes some constructive suggestion, based on the numerical results.It simulates the ventilation system of Jinping construct-assistance tunnel under normal traffic, blocked traffic and jam conditions, using the tunnel ventilation control program, to investigate the effect of the neural network on-line control system on ventilation in road tunnels. The results shows that the control system can modify the control strategy and turn on fans appropriately to prevent excess of the pollution concentration. And confirm the robustness of the designed neural network on-line control system applied to single-line road tunnel using bidirectional air exchange ventilation.更多还原