【作者】 朱艳峰；

【导师】 吴亚平；

【作者基本信息】 兰州交通大学 ， 桥梁与隧道工程， 2010， 博士

【摘要】 高速铁路的快速发展,使得深埋大、距离长的隧道需求日益增长。由于纵向距离很大,列车速度的不断提高以及行车密度和客运量的与日俱增,高速列车能耗及附属设备产生的大量热量将释放到隧道环境中。在通风不畅,土壤及隧道结构散热不是很好的情况下,会引起隧道内热量的积聚和隧道纵深方向温度的不断升高。相当多的热能转换到隧道壁中,导致隧道内壁发生严重的剥蚀现象以及寒区隧道的融沉破坏。论文围绕高速列车隧道系统,考虑长隧道内高速列车运行的三维空气动力学效应,空气与围岩的对流换热以及围岩热传导,对长隧道内温度变化以及隧道周围岩体温度场特征进行了研究。具体表现在：1.以流体力学和传热学理论为基础,考虑空气与围岩对流换热,建立了三维粘性、可压缩、不等熵非定常流模型。应用有限体积法,对长隧道内运行的高速列车进行三维空气动力学分析。本文详细分析了不同阻塞比(0.13,0.21,0.32)、不同列车速度(350km/h,432kh/h,500km/h,600km/h)、不同车头形状(30°,45°,60°)下高速列车在长隧道中运行时,隧道内车周三维速度场、压力场,探究了列车运行阻力产生的机理,计算了车头车尾的压差阻力,车身表面的摩擦阻力,比较了不同工况下列车在隧道中运行时的阻力系数,得到了列车克服全部阻力高速运行所需能耗产生的热量。隧道内热量的来源主要是用来克服列车运行阻力而消耗的牵引能。热量的积聚与列车隧道系统阻塞比的关系非常大,隧道内热效应受到列车速度的影响仅次于阻塞比,改变列车头部形状,也可改变释放到隧道内的热量。行车密度对温度的影响也是非常关键的,隧道内温度的升高与列车空调放热也密切相关。环境压力水平与列车能耗直接相关,采用低压真空隧道会显著降低长隧道内的温度升高。2.将有限体积法与有限元单元法结合,运用传热学、固体力学的基本理论,考虑空气与围岩的对流换热和围岩热传导耦合,建立了温度应力耦合计算模型。温度变化对岩体的应力影响,通过将温度作用产生的初应变转化为初始荷载累加到荷载向量中实现,对隧道内空气与围岩对流换热及围岩热传导耦合问题进行了三维非线性分析。分别求解了阻塞比为0.13,0.21及0.32下高速铁路隧道在不同速度及不同车头情况下,一年期、十年期、二十年期的围岩温度场,热应力场。结果发现,隧道围岩温度场在二十年后都将维持一个比较稳定的状态,围岩等效热应力值在隧道壁四周基本呈均匀分布,温度引起的等效热应力最大值及最大主应力均出现在隧道拱角处。3.针对多年冻土地区隧道围岩温度场是具有导热与对流换热耦合边界并伴有相变的非稳态温度场的特点,建立了隧道内空气对流换热的微分控制方程,同时,在非稳态的温度场控制方程基础上,建立了伴有相变的冻土体非稳态温度场控制方程。本文用有限体积法求解隧道内气流及用有限单元法求解冻土体的非稳态温度场偏微分方程,采用了空间域内的有限单元法与时间域内的有限差分法混合求解,进行了围岩温度场的有限元分析。最后通过阻塞比为0.13及0.21,列车速度为500km/h的工况为例,预测了寒区高速铁路隧道在二十五年间长期连续不断地运营后,隧道内温度的升高以及围岩温度场的变化。结果表明,二十年后,寒区高速铁路隧道内环境温度的变化速度将非常缓慢,基本维持稳定,隧道内热量积聚对冻土融化范围的影响将维持在一定的范围,热熔沉降将是寒区高速铁路隧道一个需要考虑的因素。更多还原

【Abstract】 With the development of high-speed railway, the demand of longer and deeper buried tunnel is highly increased. Because of long lengthways distance, continually increased in train speed, traffic density and passenger capacity grow day by day, a significant amount of thermal energy may be transferred to the tunnel environment. This thermal energy is the result of dissipation caused by aerodynamic drag, mechanical resistances, various electric equipments and air condition etc. Bad air ventilation and not enough heat dissipation with soil and tunnel structure limits the heat driven out timely. As a consequence, heat-accumulating and air temperature in the deep buried long tunnel can be increased continually. Quite a number of this thermal is transferred into the tunnel wall. It will result in bad denudation in tunnel wall and thawy subsidence in Frigid Zone. The subject matter of this paper is in view of high speed train tunnel system. Temperature field generated by high speed train in long tunnel and surrounding rock is studied. Three-dimensional aerodynamic effect induced by train traveling through long tunnel, heat conduction of surrounding rock and heat convection between air and rock wall is taken into account. The concrete manifestation is:1. Based on the theory of fluid mechanics and heat transfer, taking into account of heat convection between air and tunnel wall, three-dimensional unsteady viscous, compressible, non-isentropic flow field model is established. Three-dimensional aerodynamic effect induced by high speed train traveling through very long tunnel is analysed by finite volume method. 3-D velocity fields, pressure distribution around train are simulated with different blocking ratio (0.13,0.21, and 0.32), multifarious head shape (30°,45°, and 60°) and various speed conditions (350km/h,432kh/h,500km/h, and 600km/h). Mechanism of aerodynamic drag is investigated and pressure drag between train nose and train tail, friction drag on train suface is calculated. So the resistance coefficients that high speed train running in different cases is compared with each other. As a result, the quantity of heat produced by the train power consumed that train against all resistance is evaluated.The quantity of heat in the tunnel main consists of power consumed by train traveling at high speed through a long tunnel. The heat-accumulating in long tunnel is more related to blockage ratio. Train speed is next to blockage ratio in influencing thermodynamic effect. As train nose shape varied, quantity of heat released into the tunnel space will be changed too. Traffic density is also very important to tunnel temperature. In addition, temperature in tunnel would be increased further with train air conditioning system. Train energy consumption is directly proportional to the environmental pressure level. Continual temperature rising in long tunnel will be significantly reduced by partial vacuum in contrast to atmospheric conditions. 2. In this paper, finite volume method is combined with finite element method. A new coupling calculation model of temperature-stress is established based on the theory of heat transfer and solid mechanics, heat convection between air and tunnel wall and heat conduction of the rock surrounding the tunnel has also been comprehensively considered. The rock stress resulted in temperature change is carried out by the way of translating temperature initial strain into initial load, then adding it to load vector. The coupled problem of heat convection between air and tunnel wall, heat conduction of surrounding rock is solved in terms of three-dimensional nonlinear analysis. The temperature and thermal stress fields of surrounding rock in one year, ten year and twenty year is evaluated, under the condition of high speed train tunnel system with blocking ratio (0.13,0.21, and 0.32), various train head shape and differents train speed. As a result, the temperature fields of rock will be keeping relative steady state after twenty years. Equivalent thermal stress is uniform distributed all around the tunnel wall. The maximum principal stress and maximum equivalent thermal stress caused by temperature change all exists in arch corner.3. Aiming at the characteristies that the temperature field of permafrost culvert is a non-steady temperature field with phase changing and with conjugated heat transfer on fluid thermal boundary, differential control equations for convective heat transfer of tunnel air are established. The govening equation of the non- steady temperature field with phase changing of the permafrost based on the tradltional equations also formulated. Differential control equations for tunnel air are solved by finite volume method and partial differential equations for frozen soil are solved by finite element method. Rock temperature fields are anlyses with the mixture solution method, by adopting the grid segmentation in space domain with finite element method and format segmentatlon in time domain with finite difference method. With the simulation results of blocking ratio 0.13 and 0.21, train speed 500km/h, the temperature change in tunnel space and the temperature field of surrounding rock is predicted after twenty five years successive train movements in cold region high speed railway tunnel. The results show that the rate of air temperature changing in tunnel is very slowly after twenty years. It will be keeping a relative steady state. The thawed range of the permafrost surrounding the tunnel in cold regions can be maintained under relative conservative ranges. However thawy subsidence is still a factor that needs to be considered in high speed railway tunnel of Frigid Zone.更多还原