• KIEAE Journal
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• 제4권3호
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• pp.203-210
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• 2004

This dissertation identifies and investigates the possible control modes of hybrid ventilation system in applying to general apartments. It evaluates range of hybrid ventilation control modes in terms of indoor air quality, thermal comfort, and energy consumption in a living room and a kitchen of the $1000m^2$ apartment. The TRNSYS simulation program was used for evaluating the following four ventilation types : A ventilation mode relying on only infiltration for supplying air, A natural ventilation mode considering with weather condition, A hybrid ventilation (natural + mechanical ventilation) mode allowing minimum ventilation with no heat exchange, and a hybrid ventilation mode with heat exchange. This study shows the following results. As temperature being controlled by heating cooling equipments, there is without significant difference in thermal performance among ventilation types. Regarding Indoor Air quality, Indoor air contamination level of the hybrid ventilation case consistently keep the lower levels. The hybrid ventilation modes consume more energy by a 49% as compared to the A ventilation mode relying on only infiltration for supplying air. It is caused by the continuous ventilation for keeping good indoor air quality; the increase of energy consumption can be attributable to the increase of the heating energy. Therefore, the heat exchange between indoor and outdoor air is required during heating season in severe weather conditions. During the cooling seasons, Introducing natural ventilation can achieve energy saving by 40 ~ 45%. Thus, it can be an effective strategies for energy saving. Based on these results, a hybrid ventilation system can be suggested as an effective ventilation strategy for archiving high level of indoor air quality, thermal comfort, and energy consumption.

• 한국태양에너지학회 논문집
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• 제38권4호
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• pp.67-76
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• 2018

Cooling the building by natural ventilation is one of the passive methods widely used from ancient times. It can be effectively applied especially in case of cooling load during the intermediate season of the year. In this study, the effect of 4 cases of window ventilation control mode which are 'Always Close', 'Temperature', 'Enthalpy' and 'Always Open' is simulated by Energyplus program and analyzed to improve the comfort of occupants and reduce energy consumption of the school classroom.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.269-272
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• 2006

The heat and smoke which generated by subway under fire is one of the most harmful factor in air tighten underground station. To prevent this, Trackway Exhaust System(TES) can be used. The heat released from the train running in the tunnel raises the temperature at the platform and the trackway, and thus proper ventilation system is required for comfortable underground environment. When the fire is occurred, TES is operated as smoke exhaust mode from normal ventilation mode. In the present study, the subway station which is one of the line number 9 in Seoul subway is modeled, and fired situation is simulated with several ventilation mode of ventilation system in trackway. For this simulation whole station is modeled. Non steady state 3D simulation which considered train under fire is entering to the station is performed. Temperature and smoke distribution in platform and trackway are compared. To represent heat by fire, heat flux was given to the fired carriage, also to describe smoke by fire, concentration of CO is represented. As the result of present study, temperature and smoke distribution is different as the method of ventilation in trackway and platform is changed. In over side of trackway, the fan must be operated as exhaust mode for efficient elimination of heat and smoke, and supply mode of fan operation in under side shows better distribution of heat and smoke. The ventilation system which is changed from ventilation mode to exhaust mode can be applied to control heat and smoke under fire.

• 한국방재학회 논문집
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• 제8권3호
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• pp.37-42
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• 2008

본 연구는 지하철에서 화재발생시 최적의 제연모드 예측을 목적으로 수치해석을 수행하였다. 현재 국내 지하철 화재발생시 제연모드는 승강장 내 화재구역 배기, 비화재구역 급기 또는 정지로 설정 되어있다. 수치해석 조건은 2가지 국내 비상시 제연모드 및 발화 4분(승강장 피난허용시간, NFPA 130) 이전까지 승강장에서 배기를 하며, 발화 4분이 후 터널 배기로 전환되는 스위치모드의 3가지 경우에 대하여 비교 분석하였다. 승객 호흡높이(1.7 m)를 기준으로 열, 일산화탄소 및 가시거리를 비교하였다. 수치해석 결과 급기팬 작동은 연기를 교란시키고 확산시킬 수 있으며, 또한 승강장 및 터널 제연모드로 작동할 경우 승강장의 제연모드로만 작동한 경우에 비하여 연기 배출에 효과적임을 확인할 수 있었다.

• 한국전산유체공학회지
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• 제13권4호
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• pp.8-12
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• 2008

Heat/smoke detectors are installed in most subway platforms in Korea to detect fire. Subway platform is divided by smoke-control zones for efficient smoke-control. Once the detectors detect heat or smoke, the smoke-control ventilation system in the platform and concourse is activated according to the smoke-control ventilation mode. Smoke-control mode during fires in Korean subway platforms is that the smoke zones operate by exhausting smoke while other zones in the platform and in the concourse which is the upper floor of the platform operate by supplying air or stopping any ventilation. This study is conducted to evaluate performance of passengers' evacuation for various smoke control modes in the subway station. Distribution of smoke and heat due to fire on the platform is analyzed by using Fire Dynamics Simulator(FDS V 4.06) of NIST. Various smoke-control ventilation modes and locations of fire are considered. Evacuation and movement of passengers within the platform is simulated by building EXODUS V.4.0.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.276-279
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• 2008

Heat/smoke detectors are installed in most subway platforms in Korea to detect fire. Subway platform is divided by smoke-control zones for efficient smoke-control. Once the detectors detect heat or smoke, the smoke-control ventilation system in the platform and concourse is activated according to the smoke-control ventilation mode. Smoke-control mode during fires in Korean subway platforms is that the smoke zones operate by exhausting smoke while other zones in the platform and in the concourse which is the upper floor of the platform operate by supplying air or stopping any ventilation. This study is conducted to evaluate performance of passengers' evacuation for various smoke control modes in the subway station. Distribution of smoke and heat due to fire on the platform is analyzed by using Fire Dynamics Simulator(FDS V 4.06) of NIST. Various smoke-control ventilation modes and locations of fire are considered. Evacuation and movement of passengers within the platform is simulated by buildingEXODUS V 4.0.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2005년도 추계 학술대회논문집
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• pp.207-212
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• 2005

In designing a ventilation system of a road tunnel, a possibility of using the system as a smoke control system in case of a tunnel fire has to be considered. In the present study, a numerical simulation on ventilation system is performed considering jet fan operations and moving traffic. A fire-mode operation by reversing some fan operations in case of a tunnel fire is also simulated. The results show that ventilation operation can control the pollutants effectively, and fire-mode operation can control smoke and temperature effectively to prevent a disaster.

• 설비공학논문집
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• 제19권2호
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• pp.142-148
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• 2007

The purpose of this study is to suggest the effective ventilation strategies and control methods that can minimize energy cost maintaining acceptable IAQ level in apartment house. The effects of the air-cleaning and heat-recovery ventilation system on IAQ under various operating conditions are investigated based on the experimental and CFD analyzed results. The results can be summarized as follows. (1) When a ventilator is not operated, the concentration of several pollutants may highly show in the house even though environment-friendly building materials are applied. Therefore, a mechanical ventilation system is required to obtain proper ventilation. (2) The pollutant concentration is noticeably deceased under air-cleaning/ventilation mode of air-clinic system, however, pollutant of kitchen is stagnant, because fresh air is not carried into the kitchen. (3) When air-clinic system is only equipped at master bedroom and living room, the system does not effectively deliver fresh air throughout the whole house, and then high pollutant concentration is obtained in each room. In contrast the average pollutant concentration meets the guideline when air-clinic system is installed at each room. (4) The air-cleaning/ventilation mode significantly affects on room ventilation in comparison with ventilation mode only.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.405-410
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• 2006

This paper presents a control algorithm of supply and exhaust diffusers by recognizing a contaminant source location. CFD analysis has been conducted to calculate steady state airflow and concentration distributions in a model room, which has two supply and two exhaust openings on the ceiling. Calculations have been performed for five cases out of nine different ventilation modes by combining on/off control of the supply and exhaust openings. Local mean residual life times are obtained and compared at 9 internal points for each ventilation case. Depending on the contaminant source location, the ventilation system is operated at an optimum ventilation mode, which can results in maximum exhaust performance.

• 한국전산유체공학회지
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• 제11권4호
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• pp.20-25
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• 2006

In the present study, flow characteristics inside a road tunnel are simulated for the ventilation flows due to jet fan system and flows induces by the traffic. Traffic ventilation is numerically simulated by multiple reference frame. From the results of steady state simulation of tunnel ventilation, it is found that the proper ventilation is achieved by the designed jet fan system along with ventilating flow induced by the traffic. A transient simulation is also performed for the case of vehicle fire in the tunnel reversing the direction of rotation of some fans. The results suggest that the heat and smoke can be controlled by the proper changing of fan operation mode. The present results can be used to design proper ventilation system and effective smoke control system as well.