城市中长距离沉管隧道风机开启策略及污染物分布规律研究  

Opening Strategy of Middle and Long Distance Immersed Tunnel Ventilation Fans in Urban Areas and Distribution Pattern of Pollutants

作　　者：唐宏辉 魏立新 徐志胜[2] 赵家明 于子涵 王娟[2] 谢艺强 TANG Honghui;WEI Lixin;XU Zhisheng;ZHAO Jiaming;YU Zihan;WANG Juan;XIE Yiqiang(Guangzhou Municipal Engineering Design&Research Institute Co.,Ltd.,Guangzhou 510000,Guangdong,China;Disaster Prevention Science and Safety Technology Institution,Central South University,Changsha 410075,Hunan,China;CABR Fire Safety Science&Technology Co.,Ltd.,Beijing 100013,China)

机构地区：[1]广州市市政工程设计研究总院有限公司,广东广州510000 [2]中南大学防灾科学安全技术研究所,湖南长沙410075 [3]建研防火科技有限公司,北京100013

出　　处：《隧道建设（中英文）》2024年第S01期71-81,共11页Tunnel Construction

基　　金：广州市市政工程设计研究总院有限公司技术开发委托项目(2021-093-FK)。

摘　　要：城市内中长距离沉管隧道工程由于受到地质地貌条件的限制,可能存在W型复合坡度且中间不设置风塔的结构特点。针对城市内不设风塔的沉管隧道,其运营风机开启策略及污染物分布规律有待进一步研究。采用数值模拟,主要考虑隧道不同区段的阻滞(入口段、中间段、出口段及全线阻滞)和不同风机的开启数量(3、5、6、7组),来研究隧道内污染物分布规律。研究结果显示:1)随着风机开启台数的增多,隧道内顶部流速增大;2)在阻滞时,阻滞段对风机射流发展段的流场分布影响较为显著,增加隧道风机开启台数对阻滞段污染物体积分数的影响较小,主要影响非阻滞段的污染物体积分数;3)在隧道中心变坡点放置风机对隧道内流场分布以及稀释CO污染物的作用有限,原因是射流在坡度变化的影响下提早撞击隧道壁面,从而影响了射流的发展;4)隧道污染物容易在隧道后半段积累,因此在设计时应考虑在隧道后半段增设射流风机;5)通过综合分析类似工程出口CO体积分数后发现,目前国内规范所采用的CO体积分数设计标准较保守,容易造成资源的浪费。Due to constraints imposed by geological and topographical conditions,urban long-distance immersed tunnel projects may exist structural characteristics with multiple slopes forming a W shape,without the installation of wind towers.For such urban tunnels without wind towers,their opening strategy of fans and pollutant distribution patterns need to be further studied.In this paper,numerical simulation is employed,mainly considering different segments with obstruction(entrance section,middle section,exit section,and full blockage)and varying numbers of fans(3,5,6,and 7 groups)being activated,to investigate the flow field and pollutant distribution patterns.The results indicate that:(1)The ceiling tunnel wind speed inside the tunnel increases with the growing number of activated fans.(2)When considering blockages,it becomes evident that the obstructed section exerts a more pronounced impact on the flow field distribution within the expanding fan jet region.The increase in the number of tunnel fans has a minor impact on the pollutant concentration in the obstructed segment,primarily affecting the pollutant concentration in the non-obstructed segment.Fans located at the slope change point in the center of the tunnel have limited effects on the distribution of the flow field inside the tunnel and the dilution of CO pollutants;This is because the jet is prematurely impinged on the tunnel wall due to the influence of slope changes, affecting the jet′s development. (4)Accumulation of pollutants is anticipated in the latter portion of the tunnel, suggesting the need to contemplate the incorporation of supplementary jet fans within this segment during the design. (5)After comprehensively analyzing the exported CO concentration of similar projects, it was found that the design criteria for CO concentration adopted in the current domestic specifications are conservative, which can lead to a waste of resources.

关 键 词：隧道通风 沉管隧道 射流风机 风机开启策略 

分 类 号：U459[建筑科学—桥梁与隧道工程]