隧道掘进通风方式与风量计算

本文对隧道施工掘进中的通风方式、风量及设备选型等问题进行了较为系统的论述,提供了隧道施工通风的计算方法,在隧道施工中具有借鉴作用。     

浅谈公路隧道通风量的计算

针对公路隧道通风计算中存在的问题，对车辆有害物的基本排放量、修正系数、阻滞模式、允许浓度等做了较为详细的论述。介绍了公路隧道通风量的计算方法，以保证隧道的交通功能。     

CFD analysis of a realistic reduced-scale modeling equipped with axial jet fan

Typically, in the experimental scale road tunnel model, the air flow induced by ventilation system is provided by an external fan. In this paper, the authors have numerically simulated full and reduced-scale tunnel in order to evaluate the possibility to realize a reduced scale of a road tunnel model with a realistic ventilation system consisting of impulsive jet fans.In particular, two different types of longitudinal ventilation systems were considered, traditional and alternative. The last one was equipped with jet fans that have the inlet/outlet sections inclined at a fixed pitch angle (α=6°) toward the tunnel floor. The jet fan was simulated as a simple momentum source that provides a pressure rise (pressure drop) across them as a function of the outflow air velocity.The analyzed tunnel consists in a 800 m one directional bore with circular cross section 5.05 m radius; the jet fans were installed at 5.67 m from the floor. Furthermore a burning Heavy Good Vehicle (HGV), placed at 450 m far away the tunnel entrance, was considered. To simulate numerically the burning vehicle, the species transport equation combustion model with Eddy-Dissipation-Concept (EDC) model was adopted.In order to create a reduced-scale model from a full scale, Froude method was applied to preserve geometrical, kinematical and dynamical similitude. Temperature and axial velocity profiles, in different tunnel sections for both considered models (full and scaled) and ventilation systems, were provided. The numerical results showed a good agreement for the both ventilation systems.     

拉平引水隧洞施工中的通风技术

介绍了拉平引水隧洞的施工过程，主要就隧道小断面、长距离通风方案的选择、通风参数的确定及通风机械设备的选型进行了论述。同时强调应采取适当措施以减少漏风率，提高通风效果。     

利用竖井自然通风辅助机械通风的关键参数研究

为了解决长大隧道中如何有效利用竖井自然通风辅助机械通风,提高通风效果、节约能耗,以锦州地下储油洞库群和官田隧道的施工通风为依托,采用理论分析、数值模拟及现场测试对竖井自然通风效应的影响参数进行了研究。研究结果表明,在特定的气温条件下,竖井进行自然通风会对机械通风有辅助的效果;竖井的直径变化对通风的作用影响是比较有限,当竖井的深度在250 m以前时,竖井通风效应随竖井深度的增大而增强。当竖井深度达到250 m后,继续增加深度,其通风效应无显著变化。温差越大,竖井自然通风效果相对越好,冬季利用竖井出风的通风效果要好于夏季利用竖井进风的通风方式;该竖井进风方案的要点在于如何将新鲜的风引入到主洞室,在距竖井的中线5 m处布置风机比较科学合理。     

隧道施工中的通风方法与改进措施探究

在大型的隧道工程施工中,隧道通风十分的重要,直接影响着隧道工程的整体质量。本文主要针对隧道工程施工中的通风方法进行深入分析,探究隧道施工中的改进措施,以提高隧道施工通风环节的质量水平。     

公路隧道火灾通风计算的改进

现有的公路隧道火灾通风计算方法,是按正常运营通风设计的风机配置,考虑火灾发生后一定数量风机的损坏,计算火灾情况下能够提供的隧道内风速,用该风速和阻止烟流逆流的临界风速比较来验算火灾时期通风的安全性。但在公路隧道的火灾过程中,火灾烟流阻力确实存在,且对隧道火灾时的烟气流动影响较大。本文将烟流阻力引进传统的公路隧道通风计算中,给出了公路隧道火灾通风时的改进计算公式。通过算例,证明了改进的计算方法更符合隧道火灾时实际概况,为隧道火灾时的通风控制提供了科学依据。     

Performance validation of a hybrid ventilation strategy comprising longitudinal and point ventilation by a fire experiment using a model-scale tunnel

We examined the exhaust performance of a hybrid ventilation strategy for maintaining a safe evacuation environment for tunnel users in a tunnel fire. The hybrid ventilation strategy combines the longitudinal ventilation strategy with the point ventilation strategy which is a type of transverse ventilation strategy. The model tunnel developed by this study was scaled to 1/5 the size of a full-scale tunnel. The model-scale experiment was performed taking into consideration Froude's law of similarity. Measurement items were the distribution of temperature and concentration of smoke inside the tunnel, longitudinal wind velocity, mass flow of smoke in the point ventilation duct, and the heat release rate of the fire source. The following main conclusions were obtained. The smoke height was constant even when varying the extraction rate of smoke from the ceiling vent. The backlayering length and critical velocity of the smoke flow in the hybrid strategy could be predicted by the methodology developed by using the longitudinal strategy. The hybrid strategy maintained a safe evacuation environment on both sides of the tunnel fire.     

青边口隧道运营通风方案研究

结合工程实例,展示了隧道运营通风方案设计过程。通过综合洞口风道式通风及射流风机通风的优点,避开各自的缺点,设计了一套适合内燃机车单线铁路长隧道的通风方案,对同类单线长隧道运营通风设计具有一定指导意义。     

自然通风机理与通风口优化研究

由于城市隧道相比于山岭隧道具备更高的环境保护标准,传统的隧道出口集中进行污染空气排放的方式很难满足环保要求,采用CFD手段对顶部开孔城市隧道在不同通风孔布置方式下的隧道各段风量、通风孔的进排风量进行了深入的研究,对多种工况下的通风效率进行了比较,为实际的工程设计提供了有益的参考和借鉴。     

公路隧道通风技术现状及发展趋势

隧道通风系统对保障公路隧道内有一个安全、健康、舒适的行车环境而言是必不可少的。文章介绍了公路隧道通风系统的发展概况、公路隧道通风系统的组成及我国公路隧道通风设计规范,阐述了国内外公路隧道常用的自然通风方式、纵向通风方式、横向式通风方式、半横向式通风方式、混合式通风方式及其特点,对公路隧道的通风控制方法(包括直接控制法、间接控制法、程序控制法、组合控制法和基于模糊控制的现代控制方法)和通风节能方案、节能控制方式、节能计算以及通风设备的选型和布置进行了总结,最后指出了公路隧道通风系统未来发展的主要趋势:综合化、网络化、智能化和节能化。     

城市隧道自然通风经济性研究

城市公路隧道通风设计是隧道总体设计的重要环节之一,合理的通风方案设计应综合考虑到通风卫生效果、设备投入、运营成本等因素.某城市隧道采用自然通风方式,在满足安全卫生要求的同时,可以削减隧道建设运营成本.文中结合工程实际情况,评估了三种机械通风方式,重点对比分析了自然通风和全射流纵向通风经济性能,最后得出采用自然通风总投资可以节约30%左右,具有显著的经济效益,并为公路隧道通风工程建设提出针对性建议.     

公路隧道通风设计的理念与方法

分析了公路隧道通风设计存在的主要问题,提出隧道通风可靠性设计的理念,建立了基于服务水平的通风设计法—红灯设计法。对于交通量和控制车速这两个通风参数的选取,应采用交通工程的理论与方法来确定,从而达到既满足规范要求,又满足运营需要与节约工程投资的目的。     

Investigation of the effect of tunnel ventilation on crib fires through small-scale experiments

This paper adopts a series of 1:20 scale tunnel experiments based on a series of large-scale tunnel experiments to study the influence of forced ventilation on fires. The small-scale tunnel has dimensions of 0.365 m (W)×0.26 m (H)×11.9 m (L). Cribs using a wood-based material provide the fuel source and forced ventilation velocities from 0.23 to 1.90 m/s are used. From the study of the measured heat release rate (HRR) and mass loss rate data it is found that the forced air velocity affects the fire spread rate and burning efficiency and further affects peak HRR values at different air velocities. A simple model to describe these influences is proposed. This model is used to reproduce the enhancement of peak HRR for cribs with different porosity factors noted by Ingason [1] and to assess the effects of using different length of cribs on peak HRR. The results from these analyses suggest that different porosity fuels result different involvement of burning surface area and result different changes in peak HRR. However, no significant difference to the enhancement on fire size is found when the burning surface area is similar. It is also found that the trend in the enhancement on fire size by using sufficiently long crib and available ventilation conditions matches the predictions of Carvel and Beard [2] for two-lane tunnel heavy goods vehicle fires.     

高瓦斯隧道施工通风设计

通过云顶高瓦斯隧道施工通风,详细介绍了瓦斯隧道通风方案、通风计算、风机的选型,以完善高瓦斯隧道的通风设计,保证高瓦斯隧道的施工安全,对类似瓦斯隧道施工通风具有借鉴作用。     

大型山地城市隧道通风及消防问题研究

随着社会经济的发展,城市中心区行车难停车难的问题越加严重,发展中心区地下交通成为解决上述问题的有效方法之一。本文就重庆市解放碑地下环道项目,提出了利用现有隧道通风模式结合建筑防火分区、防烟分区划分的方法,通过消防性能化评估的方法来解决此类地下隧道的通风及消防问题。     

北天山隧道的通风与经济性

为了满足隧道正常生产通风要求,并结合现场实际情况,提出了通风机进洞方案,详细介绍了长大隧道通风布置的具体做法,成功解决了北天山隧道通风这一技术难题,取得了理想的效果。     

重庆市嘉华隧道通风系统设计

结合工程实际情况,对目前重庆主城区最大隧道嘉华隧道的通风方式选择、需风量计算、风机组合设计等具体过程以及火灾时的通风控制进行了介绍,以满足车辆正常行驶条件下的隧道需风量。     

土地坳隧道通风设计与数值模拟

对土地坳隧道进行了通风计算,选定了风机类型和风机数量,并对隧道通风进行了数值模拟,建议在条件允许的情况下,应对隧道内的速度场以及压力场进行实际测试,并与数值模拟结合优化设计,为同类型隧道通风计算提供参考.     

包兰铁路青天寺隧道运营通风及防灾救援设计

青天寺隧道长度超过20 km,隧道的运营通风、防灾及救援(含紧急救援站)等,考虑的因素非常多,本文通过包兰铁路青天寺隧道运营通风及防灾救援设计的工程实例,介绍了特长隧道运营通风及防灾救援设计主要应考虑的问题和工程措施。通过数值模型计算,青天寺隧道运营通风得出可采用自然通风方式的结论;论述了定点救援和隧道内随机停车救援的原理和措施;对隧道内需要设置的通风机功率进行了详细的计算,对不同火灾工况的防灾通风形式、人员的疏散、风机的配置等进行了系统的论述。为以后类似工程设计提供参考。