• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.3-4
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• 2014

Power line in electric power tunnel generate heat around during power transmission. Rising temperature inside the electric power tunnel reduces the transmission efficiency of the power line. In this study, trying to understand the change in temperature in the electric power tunnel by forced ventilation and natural ventilation when the temperature rise of the electric power tunnel. The results show that average temperature in electric power tunnel by natural ventilation, forced ventilation is $56.55^{\circ}C$, $23.25^{\circ}C$. Therefore electric power tunnel during power transmission needs cooling or ventilation system.

• Tunnel and Underground Space
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• v.27 no.4
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• pp.195-204
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• 2017

This case study introduces the construction of large cross section tunnel for underground ventilation system in Sillim-Bongcheon Tunnel Project. In order to grant the safety and efficiency in connecting the ventilation shaft (7.8 m of width, and 6.6 m of height) to a tunnel for axial fan facility (20.8 m of width, and 12.3 m of height), gradual enlargement of tunnel cross section was employed between those and temporary support method was determined based on Q system. In addition, some original designs were revised during construction stage to improve the efficiency of excavation in large cross section tunnel. The advance length was optimized and top heading of the tunnel was excavated without partition in accordance with ground condition and numerical stability analysis results. It is believed that some experiences and considerations in this case study will be useful for the future design and construction in similar large cross section tunnel such as large underground ventilation system or road tunnel with four lanes.

• Journal of Industrial Technology
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• v.26 no.A
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• pp.3-15
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• 2006

To determine the optimum ventilation systems during long tunnel excavation, the velocity vector profile and the contaminant's distribution at working place are studied using 2-D, 3-D numerical analysis. The main results can be summarized as follow; In case of long tunnels, blower-exhaust-mixture types which enable to use soft blast ducts is most appropriate in terms of ventilation and economical efficiency. Of the same ventilation types, ventilation efficiency has a difference according to blast ducts and the distance between fan and working place. The 3-D numerical result shows that arranging blower and exhaust ducts in the right and left corners of the tunnel respectively is effective to discharge contaminant. The result of the real measurement shows that CO concentration can be reduced to below 50 ppm, which is regulation value, as 16-minutes fan operation goes on.

• Fire Science and Engineering
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• v.18 no.2
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• pp.49-56
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• 2004

Today's popular ventilation systems include the combined jet fans and electrostatic precipitation systems or the combined jet fans and vertical shaft system. Tunnels with these two ventilation systems applied have been designed and opened, more and more interest has been put in maintenance of a tunnel after opening. Therefore. it is to become more important to come up with the optimal operation mode and the method for the evaluation of ventilation system. In this study, to evaluate a tunnel ventilation and its economy, a dynamic simulation program was developed which can simulate the unsteady-state tunnel air velocity and concentration of pollutants according to the traffic flow variations and operation condition of a ventilation system. We clarified the effectiveness usage on tunnel ventilation by using it and also we could found the most economical ventilation operation mode by application in real exit tunnel. We obtained that combination of fan system and electrostatic precipitation system was more economical than jet fan priority operation mode.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.2
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• pp.147-155
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• 2005

For a long road tunnel, a tunnel ventilation system may be used in order to reduce the pollution level below the required level. To control the tunnel pollution level, a closed loop control algorithm may be used. The cascade control algorithm, which composed of a jet fan control algorithm and an air velocity setpoint algorithm, was developed to regulate the CO level in a tunnel. The verification of control algorithms was carried out by dynamic models developed from real tunnel data sets. The simulation results showed that control algorithms developed for this study were effective to control the tunnel ventilation system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.11
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• pp.1035-1043
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• 2004

For a long road tunnel, a tunnel ventilation system may be used in order to reduce the pollution level below the required level. To control the tunnel pollution level, a closed loop control algorithm may be used. The feedforward prediction algorithm and the cascade control algorithm were developed to regulate the CO level in a tunnel. The feedforward prediction algorithm composed of the traffic estimation algorithm and the CO density prediction algorithm, and the cascade control algorithm composed of the jet fan control algorithm and the air velocity setpoint algorithm. The verification of control algorithms was carried out by dynamic models developed from the actual tunnel data. The simulation results showed that control algorithms developed for this study were effective for the control of the tunnel ventilation system.

• Journal of the Korean Society of Industry Convergence
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• v.5 no.4
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• pp.313-320
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• 2002

A 2-dimensional $k-{\varepsilon}$ numerical model was developed to explore the effects of vehicle movement, jet fan and wind speed for the ventilation of road tunnels. To consider the temperature distribution in the tunnel, the energy equation was solved with a source term of the energy exhausted from vehicles. Although the tunnel ventilation can be made by the piston effect of vehicle movement, an additional ventilation is necessary when a head wind is existing. Jet fans may assist the air flow in the tunnel. However, more efficient ventilation system should be necessary, because the exhaust gas from vehicles flow along the road surface and it cannot be diffused in the longitudinal tunnel.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.6
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• pp.561-571
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• 2014

The standards of ventilation system for bi-directional tunnel have not been established now. For this reason, with regard to the bi-directional tunnel below 1km, some problems have been appeared in ventilation capacity designing and in determining whether the mechanical ventilation system is needed or not for each case. In this study, we examine the characteristics of natural ventilations, analyze ongoing ventilation design cases for bi-directional tunnels and classify those cases into two groups. This study is carried out about the capability of using natural ventilating system by calculation of reasonable ventilation capacity in bi-directional tunnel and review of relationship between natural wind speed ($Vr^*$) and required speed(Vreq). This paper aims at providing a basis data for bi-directional tunnel ventilation design standards.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.3
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• pp.341-351
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• 2015

When rainfall occurred on road tunnel, that is likely to have influence upon ventilation force in the tunnels but the tunnels ventilation system did not consider factors of rainfall. Thus, this study investigated effects of rainfall upon ventilation force in the tunnels at no rainfall and changing of rainfall by 3 dimensional numerical method. Flow rate into road tunnels decreased as many as 52.34% at rainfall of 150 mm/hr, and pressure drop of road tunnel between entrance and exit decreased as many as 22.22%, so that rainfall had influence upon ventilation force in the tunnel. The number of necessary jet fan in road tunnels is 12 at no rainfall but, when rainfall of 80 mm/hr on road tunnels, the number of necessary jet fan in road tunnels is 16, when rainfall of 150 mm/hr on road tunnels, the number of necessary jet fan in road tunnels is 17. So, factor of rainfall should be considered at estimation of ventilation system of road tunnel.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.474-479
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• 2008

The purpose of this paper is to estimate the fire safety in tunnels with bi-directional and/or congested unidirectional traffic where there may be people on both sides of the fire. Therefore, the spread and movement of smoke are simulated by Fire Dynamic Simulator code under different ventilation systems, longitudinal, semi-transverse, large port exhaust system. And as quantitative risk index, FED (Fractional Effective Dose) for each ventilation system are calculated and compared by existed code developed previous research.