• 설비공학논문집
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• 제15권6호
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• pp.543-550
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• 2003

In order to saving the energy for HVAC system of buildings, utilization of wind-induced cross ventilation is thought to be promising. However, utilization of natural ventilation alone is not sufficient for maintaining the human thermal-comfort such as in hot and humid regions. A hybrid air conditioning system with a controlled natural ventilation system, or combination of natural ventilation with mechanical air conditioning is thought to overcome the deficiency of wind-driven cross ventilation and to have significant effects on energy reduction. This paper describes a concept of hybrid system and propose a new type of hybrid system using radiational cooling with wind-induced cross ventilation. Moreover, a radiational cooling system is compared with an all-air cooling system. The characteristics of the indoor environment will be examined through CFD (Computational Fluid Dynamics) simulation, which is coupled with a radiation heat transfer simulation and with HVAC control in which the PMV value for the human model in the center of the room is controlled to attain the target value.

• KIEAE Journal
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• 제7권4호
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• pp.51-56
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• 2007

This study focuses on developing natural ventilation system which is able to satisfy the good indoor air quality and air speed. The natural ventilation system developed in this study is for double window façade and it has two operation modes for summer and winter. Operational sections of the devices have been analyzed by CFD simulation to calculate discharge coefficients of openings and estimated indoor air speed. For the analysis of the appropriate installation area ratio for each room and the optimum installation area, TRNFLOW simulation has been used. As the results, we could see that the natural ventilation system can provide the similar pollutant removal performance to 0.7 ACH of mechanical ventilation with appropriate installation area and installation area ratio.

• 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.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.685-688
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• 2009

On account of Indoor Air Quality(IAQ) deterioration by reason of high insulation and air tightness for energy saving, absence of energy efficiency ventilation system development that can be domestic existing window system, the cost increase and the energy addition loss by mechanical ventilation for IAQ improvement, the ventilation obligation making design standard was prepared by a social and technical background and the necessity. In this study, an optimized design and simulation Analysis of natural ventilation window system classified by Apartment type was evaluated by CFD Computational analysis.

• 한국태양에너지학회 논문집
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• 제25권2호
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• pp.71-79
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• 2005

In this study, the ventilation performance of mechanical ventilation system in apartment House was analyzed through model test according to characteristics of air-vent. Then adequate interval of air-vent was suggested using computer simulation which will create comfort environment through improvement of ventilation performance in apartment house. The result of experiment with separation plate to prevent mixture of contaminated exhaust air with fresh supply air, the ventilation efficiency improved about 10%. The result of simulation with horizontal location of exterior air-vent, contaminated exhaust air is mixed regardless of interval variation. Consequently, mixture of the exhaust air can be prevented through locating the supply air vent on the top side and exhaust air vent on the lower side.

• KIEAE Journal
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• 제7권4호
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• pp.57-62
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• 2007

At the moment, the reduction of building energy consumption is a unavoidable task of mankind for conserving global environment. Decreasing overall U-value of building envelope and air infiltration, especially in Korean climate condition with clear four seasons, are the obvious solutions for the objective. Thus low glazing ratio with small window openings are required for heating and cooling load reduction in buildings. Using larger window openings could provide better natural ventilation but it also increases the direct solar radiation penetration into indoor space, heat gain in summer and heat loss in winter. On the other hand, the ventilation rates decreasing problem with smaller window openings could be occurred. As a solution for it, the use of casement window can cause increasing natural ventilation rates by wing wall effect. This paper focuses on deduce the most efficient opening type of casement window in Korean climate. To estimate ventilation performance of each opening types, CFD simulation was used. The best performance of opening type in every wind direction is opening both windows to the center and the most appropriate opening type for Korean climate is also opening both windows to center.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.7-13
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• 2011

본 연구에서는 최근 증가하고 있는 대심도역사의 제연 팬 용량에 따른 연기확산영향에 대하여 분석하였다. 시뮬레이션모델은 신금호 역사(5호선, 깊이 46m)를 대상으로 하였으며, 설계된 제연 용량과 실측 제연 용량의 차이에 따른 연기확산 영향을 분석 하였다. 현장조사 및 실측을 통하여 계측된 실제 역사의 제연 팬에 관한 데이터를 화재시뮬레이션 조건으로 적용하였다. 역사전체를 해석 대상으로 하여 총 400만개의 격자를 사용하였으며, 설계된 제연성능과 실측된 제연성능에 따른 연기확산 영향 비교를 위하여 화재 시나리오를 작성하여 Case별로 화재해석을 수행하였다. 계산 효율을 높이기 위하여 MPI병렬 처리기법을 사용하였으며 해석코드는 large eddy simulation 기법을 주로 사용하는 FDS code를 사용하였다.

• 설비공학논문집
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• 제22권10호
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• pp.665-671
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• 2010

In the present study a 1D-3D numerical simulation was performed to analyze the fire safety in a rescue station of a long railroad tunnel equipped with a mechanical ventilation. The behavior of hot air was studied for the emergency operation mode of ventilation system in case of fire in the rescue station. The 1D simulation was carried out for entire tunnel region. Detailed 3D CFD simulation was performed for the rescue station area in the central region of the tunnel by using the result of the 1D simulation as the boundary condition of the 3D simulation. Various type of cross passage installation were evaluated for the prevention of smoke diffusion to suggest the optimized interval of the cross passages in the rescue tunnel.

• 토지주택연구
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• 제6권4호
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• pp.215-220
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• 2015

본 연구는 공동주택에 적용되고 있는 환기장치를 선정하고 환기장치의 에너지특성 분석과 에너지저감을 목적으로 시뮬레이션 프로그램 (ECO2)을 이용하여 환기장치 별 에너지성능평가를 수행하였으며, 아래와 같이 결과를 도출하였다. 공동주택을 대상으로 환기장치 별 에너지 효율등급평가 기준에 따른 소비량을 수행하고자 하였다. 또한 단지별 에너지소비량과 비교 검토 결과를 통하여 현재 우리나라에서 공동주택에 적용하고 있는 환기장치별 에너지 소비량 실태를 파악하였다. 중부지방의 84type, 한 개동을 대상으로 시뮬레이션한 결과, 자연환기장치의 등급용 1차에너지소요량 값은 $159.9kWh/m^2yr$, 전열교환환기장치 $161kWh/m^2yr$, 바닥환기장치 $179.7kWh/m^2yr$로 계산 되었다. 위 시뮬레이션 결과를 공동주택의 실제 현장자료로 검증하였으며, 환기장치별 에너지소요량에 대한 비율로 비교해본 결과, 전열교환환기방식이 자연환기방식에 비해 -1~6% 적은 값을 보였으며, 바닥배관환기방식이 자연환기방식에 비해 약 10~20% 더 많은 1차에너지소요량이 나타났다. 환기장치의 팬동력과 열회수효율에 따라 에너지소요량의 난방과 환기 값이 변화하며, 향후 기계환기장치의 효율화 및 최적화가 필요하다고 판단된다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2005년도 동계학술발표대회 논문집
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• pp.217-222
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• 2005

Building energy consumption according to the ventilation has been considered to be an important subject. The purpose of this study is to investigate the cooling loads in a test space with a forced ventilating system. In the test space, on/off controlled air-conditioning and forced ventilating facility were operated between 8:30 to 21:00 during 4 days and some important data like temperatures and energy consumption were measured to obtain actual cooling loads. The simulation was carried out in a mode of temperature level control using a TRNSYS 15.3 with a precisely measured air change amount and performance data of air-conditioner. Cooling loads including sensible and latent were compared between by experiment and by simulation. Both of cooling loads associated with ventilation show a close agreement within an engineering tolerance.