Air Flow Distribution Study in the Main Frame of TBM by Using Computational Fluid Dynamics - Case Sudy TBM in Chamshir Tunnel

Document Type : Research Article

Authors

1 Dept. of Mining, Geophysics & Petroleum, Shahrood University of Technology, Iran

2 Dept. of Mechanical And Mechatronics Engineering, Shahrood University of Technology, Iran

10.29252/anm.2019.1507

Abstract

Summary
The numerical study of airflow has mainly concentrated on underground mines and road tunnels. Ventilation during the construction of long tunnels, especially the ventilation of TBMs, has received less attention. This paper aims to study airflow pattern in TBMs with regard to safety and as such reduce dead zones area. The results show the airflow pattern of a TBM ventilation system, which can help to design an effective ventilation system for the TBMs.
 
Introduction
The Tunnel Boring Machines (TBMs) have revolutionized the tunneling industry to create underground space safer, healthier and more economical. Ventilation is one of the main components of mechanized tunneling. The airflow quality and the related mass flow rate in the ventilation system should be sufficient to dilute gases and remove the dust inside the tunnel. Since most of TBM crews stay and work in the mainframe area, ventilation of this zone is very important.
 
Methodology and Approaches
In this study, we modeled the TBM ventilation system using CFD method to understand airflow behavior in TBM. Numerical solution of the governing equations and boundary conditions are performed by utilizing the commercial CFD code Ansys CFX 18.1. Tests of mesh-independence were conducted based on four different meshing creations. To define the boundary conditions, airflow velocity sampling was performed using multi-point sampling method in the ductwork outlet. To complete the discretization of the advection term, the high-resolution scheme was computed. Root Means Square (RMS) <  was considered as the convergence criterion of mass and momentum equations.
 
Results and Conclusions
The results show that there is not enough air flow in 89.2% of TBM space in its current state. There are many dead zones from control cabin to the end of mainframe. The main direction of the back airflow moves along the segment feeder and increasing air mass flow has no effect in decreasing dead zones area. The results from the study present show that by increasing the air mass flow rate by 60% the volume of the dead zones in TBM is decreased by 13.42% and has no effective decrease dead zone in the personnel breathing zone. The results from the present study clearly indicate that maximum mass flow capacity of jet fans is not possible to reduce dead zones that will only increase energy costs.

Keywords

Main Subjects

Full Text

تونل انتقال آب چم­شیر به طول 7050 متر و قطر نهایی 6/4 متر در شرق استان بوشهر وظیفه انتقال آب از بند انحرافی به نیروگاه برق آبی را بر عهده دارد. این تونل به روش حفاری مکانیزه با استفاده از ماشین حفاری تمام مقطع تک سپره[i] S124 ساخت شرکت هرنکنشت در حال اجرا است. سامانه تهویه در این ماشین حفاری تمام مقطع به صورت دهشی است. به این ترتیب که هوای تازه از خارج تونل به کمک جت فن و از طریق لوله نصب شده در سقف تونل به داخل ماشین حفاری ارسال می‌شود. هوای ورودی به داخل تونل از طریق لوله تهویه پس از عبور از خشاب لوله تهویه و لوله‌های نصب شده برروی دنباله دستگاه، با فشار به قسمت سینه کار تونل هدایت می‌شود و در برگشت، هوای آلوده را به همراه خود به خارج از تونل منتقل می‌کند.

بررسی توزیع جریان هوا و آلاینده­ها در فضاهایی که میزان تولید آلاینده­ها در آنها زیاد بوده یا دهانه­های ارتباطی آن با هوای آزاد فاصله زیاد می­گیرد، بسیار حایز اهمیت است. به طور کلی اگر به مسایل مربوط به تهویه در ابتدای طراحی و یا اجرا، توجه کافی نشود، قطعاً در هنگام انجام عملیات، راندمان کاری پرسنل عملیاتی و ماشین‌آلات بسیار پایین آمده و علاوه بر آن ممکن است زیان­های عمده­ای به ماشین‌آلات و سلامت نیروی انسانی وارد شود. به عنوان مثال عدم تهویه مناسب و انفجار گاز متان در تونل انتقال آب لس‌آنجلس موجب صدمه دیدن چهار کارگر و در تونل منطقه هیگاشیمورایاما ژاپن نیز موجب کشته و زخمی شدن 11 کارگر شد]1[. در ماشین حفاری مکانیزه در تونل زاگرس نیز گاز سولفید هیدروژن، سیانید هیدروژن و متان در این تونل مشاهده شده، به طوری که غلظت گاز متان بالاتر از حد انفجار ثبت و منجر به تعطیلی عملیات به مدت چهار ماه گردید]2[.


[i] Single Shield Tunnel Boring Machine

References

[1]           Deere, D. (1981) “Adverse geology and TBM tunneling problems”, rapid excavation and tunneling conference (RETC), pp. 574-585.
[2]           Satari, G. Ajodani, S. Bathaie,H. (2011). “Mechanized Tunneling in Water and Gas Crisis, Case Study of Zagros Tunnel.” First Asian an 9th Iranian tunneling symposium (In Persian).
[3]           Heerden, J. Sullivan, P. (1993). “The application of CFD for evaluation of dust suppression and auxiliary ventilating system used with continuous miners”, 6th US Mine Ventilation Symposium.
[4]           Srinivasa Rao, B., Baafi, E.Y., Aziz, N.I. and Singh, R.N. (1993), "Three Dimensional Numerical Modelling of Air Velocities and Dust Control Techniques in a. Longwall face", Proc. of 6th U.S. Mine Ventilation Symposium, June 21 - 23, Salt. Lake City, Utah, S M E , Chapter 43, pp 287 - 292.
[5]           Wala, A., Jacob, J., Brown, J. and Huang, G., (2003). “New approaches to mine-face ventilation”, mining
Engineering, 55(3), 25-30 .
[6]           Wala, M.A., Vytla, S., Taylor, C.D., and Huang, P.G., (2007), “Mine Face ventilation: a comparison of CFD results against benchmark experiments for the CFD code validation,” Mining Engineering, Vol 59, No 10..
[7]           Parra, M.T, Villafruela, J.M, Castro, F, Mendez, C., (2006) “Numerical and experimental analysis of different ventilation systems in deep mines”, Building and Environment 41.
[8]           Aminossadati, S.M. Hooman, K., (2008) “Numerical Simulation of ventilation Air flow in underground mine working”, 12th U.S./ North American Mine Ventilation Symposium.
[9]           Zheng, Y. Tien, J.C., (2008) “DPM dispersion study using CFD for underground metal/nonmetal mines”, 12th U.S./North American Mine Ventilation Symposium.
[10]         Taylor, C.D., Chilton, J.E., Goodman, GV.R, (2010) “Guidelines for the control and monitoring of methane gas on continuous mining operations”, Department of Health and Human Services.
[11]         Stephens, M and Calizaya, F. (2010) “A Study of leakage flow in a labratory model and using CFD”. 13th  U.S./North American Mine Ventilation Symposium.
[12]         Diego I., Torno S., Torano J., Menendez M., Gent M. (2011) “A practical use of CFD for ventilation of underground works”, Tunneling and Underground Space Technology, 26 (1).
[13]         Sasmito, Agus P, Birgersson,E., Ly, H.C., Mujumdar A.S., (2013) “Some approaches to improve ventilation system in underground coal mines environment – A computational fluid dynamic study”, Tunneling and Underground Space Technology, 34.
[14]         Niknam, B & Hassan Madani (2009).,” Three Dimensional Analysis of Longitudinal Ventilation System Using Ceiling Fan (Case Study: Emamzadeh Hashem Gallery)”., Iran Tunnel magazine (In Persian).
[15]         Niknam, B & Hassan Madani (2010).,” Modeling of methane gas distribution in the mine faces with computational fluid dynamics.” 8th Student Conference on Mining Engineering(In Persian)..
[16]         Arabian, M., Azarfar, B., Osia, H., (2010).,” prefeasibility study in natural ventilation system in Tehran-Tabriz Underground railroads’, Third National Conference on Air Conditioning and Industrial Hygiene, Sharif university (In Persian).
[17]         Refahi, H., Sereshki, F., Abasnezhad, A., Dabagh Neishabori., A.,(2017).”Ventilation System Designing of the Mashhad Metro Line 2 Line 1 (Phase I) by using the CFD model.” Third Annual National Conference on Mechanical Engineering and Industrial Solutions, Mashhad (In Persian).
[18]         Kurnia JC, Sasmito AP, Mujumdar AS., (2014). “CFD simulation of methane dispersion and innovative methane management in underground mining faces”. Appl Math Model;38(14):3467–84.
[19]         Kurnia JC, Sasmito AP, Mujumdar AS., (2014). “Dust dispersion and management in underground mining faces”. Int J Min Sci Technol;24(1):39–44.
[20]         Kurnia JC, Sasmito AP, Mujumdar AS.,(2014). “Simulation of a novel intermittent ventilation system for underground mines”. Tunn Undergr Space Technol;42(5):206–15.
[21]         Feroze T, Genc B., (2017). “Evaluation of line brattice length in an empty heading to improve air flow rate at the face using CFD”. Int J Min Sci Technol;27 (2):253–9.
[22]         Kurnia JC, Sasmito AP, Hassani FP, Mujumdar AS., (2015). “Introduction and evaluation of a novel hybrid brattice for improved dust control in underground mining faces: a computational study”. Int J Min Sci Technol;25(4):537–43.
[23]         Legates DR, McCabe GJ.,(1999). “Evaluating the use of ‘‘goodness-of-fit’’ measures in hydrologic and hydro climatic model validation”. Water Resour Res;35(1):233–41.
[24]         Moriasi DN, Arnold JG, Van Liew MW, Bingner RL, Harmel RD, Veith TL., (2007). “Model evaluation guidelines for systematic quantification of accuracy in watershed simulations”. Am Soc Agric Biol Eng 50(3):885–900.
Journal of Analytical and Numerical Methods in Mining Engineering
Volume 9, Issue 19
September 2019
Pages 79-90

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History

  • Receive Date: 25 December 2017
  • Revise Date: 29 May 2019
  • Accept Date: 23 June 2019

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