特长隧道风仓接力通风关键参数及其效果研究
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摘要
通过长斜井进入正洞施工的特长隧道,往往面临独头通风距离过长、工作面风量不足等问题,造成污染物难以在规定时间排出洞外。以衢宁铁路鹫峰山隧道风仓接力施工通风为依托,采用数值模拟方法研究了风仓长度、隔板长度及风机布置方式对轴流风机通风效率的影响,分析了原压入式通风和风仓接力通风洞内CO运移特性。结果表明,风仓长度从10 m增至25 m时,轴流风机通风效率大幅提高,风仓长度大于25 m时,对轴流风机通风效率的影响不大。设置中隔板会影响空气在风仓内的分流并产生较多旋流,从而降低风机通风效率;轴流风机远离斜井端对称布置,风仓内部风流的引流速度和引流范围最大,风流运动路径最优,通风效率最高。由于压入式通风受限于斜井断面尺寸及现场布置方式,当通风距离超过3 000 m后,无法满足洞内作业环境规定的条件。在正洞与斜井交叉部位设置密封的风仓,形成接力通风,能大幅度延长通风距离,提高通风效率,改善洞内空气质量。
Relying on the relay construction ventilation example based on the air cabin of Jiufengshan tunnel in Quzhou-Nanjing Railway,the paper has done a numerical simulation to pursue the effect of the air cabin length,the partition length,and the ventilation effect and efficiency of the axial fan arrangement. As a matter of fact,it has long been a problem in the construction of the extra-long tunnels due to the long distance ventilation and insufficient air volume supply in the working face,which may cause serious pollution and the exhaust gas discharge for the special space and time. Therefore,we have done a careful analysis of the particular status-in-situ of the CO migration in the originally forced ventilation and air cabin ventilation. The results of our investigation show that,when the air cabin length increases from 10 m to 25 m,the ventilation efficiency of the axial fan has to be greatly recreated and heightened. For example,when the ventilation length is over 25 m,there may exist somewhat effect on the ventilation efficiency of the axially flowing fans. However,when the partition affects the air flow in the air cabin and generate more swirling flow,it may tend to reduce the ventilation efficiency of the fan. But,in contrast,when the axial fans are arranged symmetrically away from the inclined shaft,its velocity and drainage range of the airflow in the air cabin can reach its maximal limits. In addition,its air flow path can be optimalized with its ventilation efficiency being made to its maximal limits.Besides,since the forced ventilation of the fan is limited to the section size of the inclined shaft and the site layout method,it remains unable to meet the expected or required operating conditions in the tunnel in case the ventilation coverage is beyond 4 000 m. In such a situation,a sealed air cabin can be created at the intersection of the main hole with the inclined shaft to form a relay ventilation,so as to extend the ventilation distance to a considerable extent and enhance the ventilation efficiency as well as to improve the provision of the fresh air in the tunnel. Thus,it can be said that the research finding of the paper has created and opened up a new approach to the construction ventilation of the extremely long tunnels.
Relying on the relay construction ventilation example based on the air cabin of Jiufengshan tunnel in Quzhou-Nanjing Railway,the paper has done a numerical simulation to pursue the effect of the air cabin length,the partition length,and the ventilation effect and efficiency of the axial fan arrangement. As a matter of fact,it has long been a problem in the construction of the extra-long tunnels due to the long distance ventilation and insufficient air volume supply in the working face,which may cause serious pollution and the exhaust gas discharge for the special space and time. Therefore,we have done a careful analysis of the particular status-in-situ of the CO migration in the originally forced ventilation and air cabin ventilation. The results of our investigation show that,when the air cabin length increases from 10 m to 25 m,the ventilation efficiency of the axial fan has to be greatly recreated and heightened. For example,when the ventilation length is over 25 m,there may exist somewhat effect on the ventilation efficiency of the axially flowing fans. However,when the partition affects the air flow in the air cabin and generate more swirling flow,it may tend to reduce the ventilation efficiency of the fan. But,in contrast,when the axial fans are arranged symmetrically away from the inclined shaft,its velocity and drainage range of the airflow in the air cabin can reach its maximal limits. In addition,its air flow path can be optimalized with its ventilation efficiency being made to its maximal limits.Besides,since the forced ventilation of the fan is limited to the section size of the inclined shaft and the site layout method,it remains unable to meet the expected or required operating conditions in the tunnel in case the ventilation coverage is beyond 4 000 m. In such a situation,a sealed air cabin can be created at the intersection of the main hole with the inclined shaft to form a relay ventilation,so as to extend the ventilation distance to a considerable extent and enhance the ventilation efficiency as well as to improve the provision of the fresh air in the tunnel. Thus,it can be said that the research finding of the paper has created and opened up a new approach to the construction ventilation of the extremely long tunnels.
引文
[1] HONG Kairong(洪开荣). Development and prospects of tunnels and underground works in China in recent two years[J]. Tunnel Construction(隧道建设),2017,37(2):123-134.
[2] ZHAO Yong(赵勇),TIAN Siming(田四明). Data statistics of railway tunnel in China[J]. Tunnel Construction(隧道建设),2017,37(5):641-642.
[3] ZHANG Heng,SUN Jianchun,LIU Xiaocheng,et al. Investigation and analysis on the setting of cross passage and auxiliary passage in extra-long highway tunnel[J]. Procedia Engineering,2018,211:659-667.
[4] ZHANG Heng,SUN Jianchun,LIN Fang,et al. Optimization on energy saving ventilation of gallery-type combined construction shaft exhaust in extra-long tunnel[J].Procedia Engineering,2017,205:1777-1784.
[5] CHEN Shougen(陈寿根),ZHANG Heng(张恒). Research and practice on construction ventilation technology in long tunnels(长大隧道施工通风技术研究与实践)[M]. Chengdu:Southwest Jiao Tong University Press,2014.
[6] DOU Xiaotian(豆小天),CHEN Qinghuai(陈庆怀).Application of large plenum relay ventilation in construction of tunnel with long inclined shafts[J]. Tunnel Construction(隧道建设),2011,31(1):104-109.
[7] CHEN Haifeng(陈海锋),YANG Qixin(杨其新). Probe into air cabin ventilation in long and large tunnels construction[J]. Technology of Highway and Transport(公路交通技术),2011(5):124-128.
[8] XIN Guoping(辛国平). Combined separated duct and vent pipe ventilation techniques for a long tunnel with a large section[J]. Modern Tunneling Technology(现代隧道技术),2015,52(6):184-189.
[9] LIU Guoping(刘国平). An application of relay ventilation in the construction of a water-conveyance tunnel[J].Tunnel Construction(隧道建设), 2013, 33(9):785-790.
[10] LI Xiuchun(李秀春),YANG Qixin(杨其新),JIANG Yajun(蒋雅君),et al. The simulation computing research on air cabin construction ventilation in underground storage caverns[J]. Chinese Journal of Underground Space and Engineering(地下空间与工程学报),2015,11(2):462-468.
[11] ZHAO Dongbo(赵东波),LI Yongsheng(李永生),GOU Hongsong(苟红松). Technology for air false ceiling[J]. Tunnel Construction(隧道建设),2012,32(6):860-865.
[12] LI Aiqing(黎爱清),LIU Shijie(刘世杰). Ventilation design and construction of Guanjiao tunnel on QinghaiTibet Railway[J]. Railway Standard Design(铁道标准设计),2013(6):92-96.
[13] LUO Zhanfu(罗占夫),ZHI Changying(职常应),YUE Sheng(乐晟). Study on partition technology of ventilation inclined shaft in Guanjiao railway tunnel[J].Tunnel Construction(隧道建设), 2009, 29(4):411-414.
[14] SUN Sanxiang(孙三祥),LEI Pengshuai(雷鹏帅),ZHANG Yunxia(张云霞). Comparison of the ventilation effects between parallel-fans operation and that of serialfans in partition technique in inclined shafts[J]. Journal of Safety and Environment(安全与环境学报),2014,14(1):78-81.
[15] ZHANG Heng(张恒),CHEN Shougen(陈寿根),YANG Jiasong(杨家松). Analysis on extreme ventilation distance of forced ventilation under limited conditions[J]. Water Resources and Hydropower Engineering(水利水电技术),2013,44(7):127-130.
[16] HARGREAVES D M,LOWNDES I S. The computational modeling of the ventilation flows within a rapid development drivage[J]. Tunnelling and Underground Space Technology,2007,22(2):150-160.
[17] SA Zhanyou,LI Feng,QIN Bo,et al. Numerical simulation study of dust concentration distribution regularity in cavern stope[J]. Safety Science,2012,50(4):857-860.
[18] HAQUE M N,KATSUCHI H,YAMADA H,et al.Strategy to develop efficient grid system for flow analysis around two-dimensional bluff bodies[J]. KSCE Journal of Civil Engineering,2016,20(5):1913-1924.
[19] LEE S C,LEE S H,LEE J H. CFD analysis on ventilation characteristics of jet fan with different pitch angle[J]. KSCE Journal of Civil Engineering,2014,18(3):812-818.
[20] REN Ting,WANG Zhongwei,COOPER G. CFD modelling of ventilation and dust flow behaviour above an underground bin and the design of an innovative dust mitigation system[J]. Tunnelling and Underground Space Technology,2014,41(3):241-254.
[21] ZHANG Heng(张恒),LIN Fang(林放),SUN Jianchun(孙建春),et al. CFD analysis of tunnel construction ventilation effect based on typical roughness model[J]. China Railway Science(中国铁道科学),2016,37(5):58-65.
[2] ZHAO Yong(赵勇),TIAN Siming(田四明). Data statistics of railway tunnel in China[J]. Tunnel Construction(隧道建设),2017,37(5):641-642.
[3] ZHANG Heng,SUN Jianchun,LIU Xiaocheng,et al. Investigation and analysis on the setting of cross passage and auxiliary passage in extra-long highway tunnel[J]. Procedia Engineering,2018,211:659-667.
[4] ZHANG Heng,SUN Jianchun,LIN Fang,et al. Optimization on energy saving ventilation of gallery-type combined construction shaft exhaust in extra-long tunnel[J].Procedia Engineering,2017,205:1777-1784.
[5] CHEN Shougen(陈寿根),ZHANG Heng(张恒). Research and practice on construction ventilation technology in long tunnels(长大隧道施工通风技术研究与实践)[M]. Chengdu:Southwest Jiao Tong University Press,2014.
[6] DOU Xiaotian(豆小天),CHEN Qinghuai(陈庆怀).Application of large plenum relay ventilation in construction of tunnel with long inclined shafts[J]. Tunnel Construction(隧道建设),2011,31(1):104-109.
[7] CHEN Haifeng(陈海锋),YANG Qixin(杨其新). Probe into air cabin ventilation in long and large tunnels construction[J]. Technology of Highway and Transport(公路交通技术),2011(5):124-128.
[8] XIN Guoping(辛国平). Combined separated duct and vent pipe ventilation techniques for a long tunnel with a large section[J]. Modern Tunneling Technology(现代隧道技术),2015,52(6):184-189.
[9] LIU Guoping(刘国平). An application of relay ventilation in the construction of a water-conveyance tunnel[J].Tunnel Construction(隧道建设), 2013, 33(9):785-790.
[10] LI Xiuchun(李秀春),YANG Qixin(杨其新),JIANG Yajun(蒋雅君),et al. The simulation computing research on air cabin construction ventilation in underground storage caverns[J]. Chinese Journal of Underground Space and Engineering(地下空间与工程学报),2015,11(2):462-468.
[11] ZHAO Dongbo(赵东波),LI Yongsheng(李永生),GOU Hongsong(苟红松). Technology for air false ceiling[J]. Tunnel Construction(隧道建设),2012,32(6):860-865.
[12] LI Aiqing(黎爱清),LIU Shijie(刘世杰). Ventilation design and construction of Guanjiao tunnel on QinghaiTibet Railway[J]. Railway Standard Design(铁道标准设计),2013(6):92-96.
[13] LUO Zhanfu(罗占夫),ZHI Changying(职常应),YUE Sheng(乐晟). Study on partition technology of ventilation inclined shaft in Guanjiao railway tunnel[J].Tunnel Construction(隧道建设), 2009, 29(4):411-414.
[14] SUN Sanxiang(孙三祥),LEI Pengshuai(雷鹏帅),ZHANG Yunxia(张云霞). Comparison of the ventilation effects between parallel-fans operation and that of serialfans in partition technique in inclined shafts[J]. Journal of Safety and Environment(安全与环境学报),2014,14(1):78-81.
[15] ZHANG Heng(张恒),CHEN Shougen(陈寿根),YANG Jiasong(杨家松). Analysis on extreme ventilation distance of forced ventilation under limited conditions[J]. Water Resources and Hydropower Engineering(水利水电技术),2013,44(7):127-130.
[16] HARGREAVES D M,LOWNDES I S. The computational modeling of the ventilation flows within a rapid development drivage[J]. Tunnelling and Underground Space Technology,2007,22(2):150-160.
[17] SA Zhanyou,LI Feng,QIN Bo,et al. Numerical simulation study of dust concentration distribution regularity in cavern stope[J]. Safety Science,2012,50(4):857-860.
[18] HAQUE M N,KATSUCHI H,YAMADA H,et al.Strategy to develop efficient grid system for flow analysis around two-dimensional bluff bodies[J]. KSCE Journal of Civil Engineering,2016,20(5):1913-1924.
[19] LEE S C,LEE S H,LEE J H. CFD analysis on ventilation characteristics of jet fan with different pitch angle[J]. KSCE Journal of Civil Engineering,2014,18(3):812-818.
[20] REN Ting,WANG Zhongwei,COOPER G. CFD modelling of ventilation and dust flow behaviour above an underground bin and the design of an innovative dust mitigation system[J]. Tunnelling and Underground Space Technology,2014,41(3):241-254.
[21] ZHANG Heng(张恒),LIN Fang(林放),SUN Jianchun(孙建春),et al. CFD analysis of tunnel construction ventilation effect based on typical roughness model[J]. China Railway Science(中国铁道科学),2016,37(5):58-65.