• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.11a
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• pp.105-109
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• 2004

우리나라 지형의 특성은 약 70%가 산으로 이루어져 있다. 이러한 지형적 여건은 교통과 관련된 사회간접 자본의 증가로 이어지며, 최근에는 산업의 발전에 힘입어 교통량의 증가와 물류비용의 절감을 목적으로 철도 및 도로의 건설시 터널의 계획 및 시공이 증가되고 있는 추세이다. 이에 따라 터널의 환경개선과 화재시 제연을 목적으로 설치되는 제트팬(Jet Fan)의 용량이 차지하는 전기적 비중이 높아지고, 전압강하에 대한 손실율이 증가되고 있다. 따라서 제트팬의 설치시 배치방법과 터널의 길이에 따른 전기실 배치를 Case 별로 분류하여 전압강하를 계산하고 분석하여 가장 효율적이며 경제적인 방안을 연구하고 정리하여 향후 설계시 기초자료를 제공하고자 하였다.

• The KSFM Journal of Fluid Machinery
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• v.13 no.3
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• pp.59-64
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• 2010

To analyze the three-dimensional flow in tunnel caused by operation of jet fan, both experimental and computational studies have been conducted. The experimental analysis of tunnel flow induced by jet fan is conducted on a real-scale apparatus with jet fan and tunnel, and air velocity at the monitoring points is measured for variation of fan's RPM. The three-dimensional numerical analysis including tunnel and jet fan is carried out for the same geometric configuration as the experimental analysis. The experimental and computational results are compared to examine the applicability of the numerical method.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2765-2770
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• 2008

The purpose of tunnel ventilation system for long road tunnels is to keep certain levels of Visibility Index and the concentration of CO. Additional equipments such as jet fans are used in road tunnel to discharge pollutants in the road tunnel. The control algorism of tunnel ventilation system takes the value of sensors as input, and then gives the operation method of jet fans in tunnel as output. Information on the variation of CO concentration in tunnel when jet fans are running is needed to minimize their operation time. Numerical analysis is used in this paper because of the difficulty of conducting experiments under standard condition for ventilation of road tunnel. The concentration of CO has been calculated by using 3-dimensional CFD under transient condition with speed of cars, quantity of air ventilation, and the results for various operation position of jet fans are compared.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2000.11a
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• pp.287-292
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• 2000

최근에 각종 SOC사업이 본격화되면서 고속도로망 및 도시교통망 확충이 가속화되어 장대 터널이 급증하고 있을 뿐만 아니라 차량의 급속한 증가로 차량배기가스에 의한 터널내부 환경의 악화가 문제시되고 있다. 특히 도로터널은 반밀폐 공간으로 터널내에서의 사고는 인명피해와 막대한 재산 피해로 이어질 수 있으므로 안전운전을 위한 제반설비 및 대책이 필요하며 안전운행을 위한 가시거리 확보 및 쾌적한 환경에 대한 요구가 대두되고 있다. 따라서 터널에서 이와 같은 요구를 만족하기 위해서 기계환기설비가 투입되고 있으며 이에 대한 최적화 설계에 대한 필요성이 높아지고 있다.(중략)

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.22 no.2
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• pp.133-136
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• 2011

Background and Objectives : Previous jet ventilation is not becoming more common because of high price, making loud noise, and causing a movement of the vocal cords due to the jet stream. So we designed a new type of manually controlled jet ventilation using previous laryngoscope and introduced it's clinical application. Materials and Method : A prospective study involved 20 patients all having undergone surgical intervention under new type of manually controlled jet ventilation from June 2009 to January 2011. The prospective study was to assess the vital sign and operative and postoperative complications. Results : The Manually Controlled Jet Ventilation were performed in 20 patients. 50% of the patients have Post-located laryngeal lesion, 20% with tracheal stenosis, 20% with glottic cancer biopsy and laser cordectomy, 10% with postglottic stenosis. Conclusion : Manually Controlled Jet Ventilation (Manujet) can be used for airway surgery.

• The KSFM Journal of Fluid Machinery
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• v.14 no.5
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• pp.63-68
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• 2011

This paper presents an optimization procedure for performance improvement of a tunnel ventilation jet fan. Optimization techniques based on response surface approximation (RSA) are employed to improve the aerodynamic performance of a tunnel ventilation jet fan. For numerical analysis, three-dimensional Renolds- averaged Navier-Stokes (RANS) equations with shear stress transport turbulence model are discretized by using finite volume approximations and solved on hexahedral grids to evaluate the total efficiency at the operating condition as the objective function. Four geometric variables defining the meridional length and the thickness profile at the hub and shroud in the jet fan rotor are selected as design variables for the numerical optimization. The results of the numerical optimization show that the total efficiency of the optimized model is significantly improved in comparison with the base model.

• Tunnel and Underground Space
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• v.12 no.2
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• pp.92-98
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• 2002

In this study reduced-scale experiments were conducted to analyze smoke movement in tunnel fire with jet fan, The 1/20 scale experiments were carried out under the froude scaling using gasoline pool fire range from 6.6 to 12.5 cm in diameter with total heat release rate from 0.714 to 4.77 kW. In the case of fires under the 2.5kW, backlaying was reduced about 40cm and smoke was effectively controled in downstream of the fan when operating the fan. The smoke layer was moved down and the ceiling temperature was decreased compared to that of without fan case in upstream of the fan, but the temperature in the lower part of the tunnel was increased.

• 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.

• Tunnel and Underground Space
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• v.20 no.6
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• pp.465-474
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• 2010

Although the number of medium-length road tunnels, less than 1 km in length, has increased recently more than 30 percent each year, their ventilation and fire safety system design guidelines have not been established yet. The guidelines for long tunnel design are adopted even for the medium-length road tunnels. Therefore the necessity is brought up to optimize the ventilation and fire safety systems based on their own design guidelines. This study aims at determining the optimal start time of jet fan in case of 20 MW fires by analyzing smoke backlayering range, temperature distribution, range of poor visibility, evacuation time and critical velocity. The CFD study results are expected to contribute to propose the optimal fan operation mode.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.6
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• pp.553-560
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• 2014

The road tunnel install a vent for the purpose of ventilation and smoke control. Ventilation equipment capacity(number of jet fans) depends on from the condition that of the pressure and ventilation resistance. Pressure and the resistance under operating vehicle have affected on the drag coefficient. The drag coefficient of the tunnel have affected by the blockage effect and slipstream effects. However, when calculating the ventilation fan, are not properly consider taking into account such effects. Therefore, ventilation force may have been slightly overestimated. This paper describes the drag coefficient through a numerical analysis to calculate the equivalent resistance area that reflects the vehicle distance, and examined the equivalent resistance area. The ventilation coefficient corresponding to the result heavy vehicle mixing ratio of the present study was not clear. Equivalent resistance area had reduced by about 86% compared to the road design handbook current standards. Also it had analyzed and reduced to 62.2% compared to Korea Highway Corporation ventilation design criteria ratio, which is the old standard.