张国梁 蒋仲安 王睿

摘   要：為解决高海拔施工隧道出渣过程的排气排放物污染，改善通风排污效果，基于海拔环境参数变化和紊流扩散理论，构建了高海拔隧道气体扩散模型. 以海拔3 200 m的川藏铁路某隧道为研究背景，对洞内的环境参数和CO分布进行测定，利用SolidWorks和ANSYS建立施工隧道掌子面出渣模型，采用Fluent中的组分输运方程，对不同海拔高度的有害气体运移规律和质量分数分布进行动态模拟. 结果表明，隧道中内燃机械作业时，在靠近工作面迎头位置，CO分布不均匀，极差值较大. 在靠近隧道出口方向，CO分布逐渐趋于平稳. CO质量分数随海拔的升高而增加，而CO质量浓度却呈相反的变化趋势. 从0 m到6 km，CO质量分数上升了96%;由于环境参数变化对CO质量浓度影响的权重大于CO排放量，导致CO质量浓度下降了18%. 在保证隧道内CO质量分数不变的条件下，需风量随海拔高度呈非线性增加. 根据得到的需风量计算模型，在海拔3 200 m时，需风量约为4.95 m3/（kW·min）.

关键词：高海拔隧道;需风量;气体扩散;内燃机械;流体模拟

中图分类号：U25                                    文献标志码：A

Analysis of CO Distribution and Air Demand during

Slagging in High Altitude Tunnel

ZHANG Guoliang1，JIANG Zhong’an1†，WANG Rui2

（1. School of Civil and Resource Engineering，University of Science and Technology Beijing，Beijing 100083，China;

2. Sichuan-Tibet Railway Co，Ltd，Chengdu 610047，China）

Abstract：To solve the air pollution in the process of slagging in the high-altitude construction tunnel and improve the effect of ventilation， a high-altitude tunnel gas diffusion model was constructed based on the changes in environmental parameters at altitude and the theory of turbulence diffusion. Taking a tunnel of Sichuan-Tibet Railway at an altitude of 3 200 m as the research background， the environmental parameters and carbon monoxide （CO）concentration in the tunnel were measured. A construction tunnel slagging model was established by SolidWorks and ANSYS softwares. The component transport equation in Fluent was used to dynamically simulate the law of harmful gas migration and mass concentration distribution at different altitudes. The results show that when the internal combustion engine is operated in the tunnel， the CO distribution is uneven and the range is large near the tunnel working face head-on. Near the exit of the tunnel， the CO distribution gradually stabilized. The CO mass fraction in the tunnel increases with the increase of altitude， but the CO mass concentration shows an opposite trend. From 0 m to 6 000 m， the CO mass fraction increased by 96%， but the influence of environmental parameter changes on the CO mass concentration is more important than the CO emissions， resulting in a decrease of 18% in the CO mass concentration. As a result， the air demand increases non-linearly with altitude while keeping the CO mass fraction constant in the tunnel. According to the obtained air demand calculation model， when the altitude is 3 200 m， the air demand is about 4.95 m3/（kW·min）.

Key words：high altitude tunnel;air demand;diffusion in gases;internal combustion engines;flow simulation

随着西部地区的快速发展，对交通网络的需求日益增加，川藏和青藏等高海拔地区的盘山公路已不能满足经济的发展需求，建设穿越大山的高海拔隧道尤为重要. 近年来，海拔超过3 km的隧道在快速增多，仅川藏铁路全线设计隧道就多达198座，隧线比高达70.2%. 海拔升高，低压低氧、寒冷干燥的气候特点会给隧道建设带来新的挑战，其中施工过程中有害……