开孔率对竖井型城市隧道阻滞工况自然通风影响的分析.pdf

2015年第43卷第7期
流体机械
文章编号:1005-0329(2015)07-0077-05
开孔率对竖井型城市隧道阻滯工况自然
通风影响的分析
朱培根,仝晓娜,陈雷,王春旺,宋桦,李晓
(解放军理工大学,江苏南京210007)
摘要;为了分析开孔率对竖井型城市隧道在交通阻滯工况下对自然通风的影响,本文采用无量纲分析和模型试验的
方法对其速度场、温度场和污染物浓度场进行了研究。通过对阻滞工况下隧道内空气所受的热压浮升力与重力的无量
纲分析,得到了模型试验所需的热压通风相似准则数和温度分布相同所需散热量比例常数。利用所得相似条件搭建了
开孔率分别为2.8%、3.7%、4.5%的3组试验模型进行试验。试验结果表明,随着开孔率的增大隧道内最不利通风段的
通风效果得到改善,但竖井的建设费用大幅度提高。选择合适的竖井开孔率既能满足阻滯工况下隧道的通风要求,也能
避免开孔率盲目增大导致的初投资浪费,对城市隧道建设具有重要意义。
关键词:竖井型城市隧道;阻滞工况;无量纲分析;热压;开孔率
中图分类号:TH43;TU83
文献标志码:A
doi:10.3969/j.isa.1005-0329.2015.07.016
Analysis of the Influence about Opening Rate on Natural Ventilation
in City Tunnel at the Status of Bloc
ZHU Pei-gen, TONG Xiao-na, CHEN Lei, WANG Chun-wang, SONG Hua, LI Xiao-yun
(PLA University of Science&Technology, Nanjing 210007, China)
Abstract: In order to analyze the influence of opening rate about natural ventilation in city tunnel at the block transportation, di
mensionless analysis and model experiment were used to the velocity distribution, temperature distribution and the pollutants con
centration. The simila eon of termal-pr u vetilation an optional constant of the heat with the same temperature
distribution were obtained by the dimensionless analysis about the thermal buoyancy and gravity of the worst condition tunnel at
bloc transportation. Three experimental models were built according to the similar conditions, the opening rates were 2.8%0,
3.,. Results showed that with the increase of opening rate, the effect of the natural ventilation was improved, but the
construction cost of vent shaft increased observably. The appropriate opening rate can meet the ventilation conditions at the blo
transportation, also can avoid the waste of the initial investment from opening rate was increased blindly. The result is of great sig
nificance to the city tunnel construction
Key words natural ventilation in city tunnel; bloc transportation; dimensionless analysis; heat pressure; rate of vent shaf
1前言
有很大的影响?,而且在竖井型城市隧道通风
系统建设投资中,竖井的土建费用很高?。隧道
竖井型城市隧道因采用自然通风的方式,减内行车平均速度小于10km/h时,视为阻滞工况,
少了机械通风所需要消耗的电力,而且可以降低在这种工况下,由于车辆怠速行驶,其交通风力的
隧道的断面高度和宽度,节省了隧道的建设和运自然通风效果非常微弱“S。与此同时,大量的
营成本,具有明显的经济性。但是由于自然通风车辆阻滞在隧道中,有害气体排放量急剧增加,可
稳定性低、可靠性差,使得竖井型城市隧道具有一能对隧道内行车人员健康安全造成威胁。阻滞工
定的局限性。通风竖井的面积及比例对通风效果况下,车辆散发的热量使得隧道内部环境的空气
收稿日期:2014-12-08修稿日期:2015-07-06