• 제목/요약/키워드: natural ventilation

검색결과 430건 처리시간 0.03초

고속버스의 환기구 형태에 따른 환기량 분석 (Analysis on the Ventilation Rate of Express Bus according to the Geometry of Vent)

  • 신인환;유호천
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2011년도 춘계학술발표대회 논문집
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    • pp.174-178
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    • 2011
  • This paper deals with the free cooling system of express bus using natural energy source in order to improve the room air quality and save cooling energy. In an express bus, there are may passengers in unit area, requiring the improvement of air quality and giving higher energy saving efficiency. Particularly, the express buses running fast make it easy to take in outdoor air at a flow rate controllable with a damper mechanism. This paper proposes the analysis on the air flow achieved by a damper controlled vertically and horizontally in order not to deteriorate the ride comfort of the passengers.

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하절기 온실의 활용실태 및 열환경분석 (Actual State of Practical Use and Thermal Environment of Greenhouses in Summer Season)

  • 남상운;김문기
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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    • pp.418-423
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    • 1999
  • This study was performed to find an efficient method to overcome extremely high temperature within greehhouse in summer season. The actual states of practical use for greenhouse in hot summer season were investigated. About 21.6% of the investigated greenhouse farms were no cultivation, and most greenhouse farms were cultivating under the very inferior environment . To examine thermal enviornment of greenhouse according to cooling or assistant cooling , greenhouses were treated with natural ventilation, shading, roof sprinkling , and evaporative cooling with air cool fan. Shading and operating air col fan showed a drop in temperature of 3.8∼4.2$^{\circ}C$ as compared with natural ventilation, and most greenhouse air temperatures were maintained below 35$^{\circ}C$.

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건물주위의 이차원 난류류동장에 대한 수치적 해석 (A Numerical Study on Two-Dimensional Turbulent Flow Field Around a Building)

  • 원성필;이동환
    • 대한설비공학회지:설비저널
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    • 제16권2호
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    • pp.166-175
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    • 1987
  • The heat loss of a building within a wind flow field results from convection and natural ventilation. Loss from natural ventilation is much more than one from convection, and the former depends mostly on the pressure distribution at the building surface. Therefore, the objective of the present study is to calculate the pressure distribution and investigate flow phenomena, around the building with a rectangular shape in a two-dimensional turbulent flow field. The finite difference method, modelled upon the turbulence $k-\epsilon$ model, has been applied to the analysis. The results, followed by the changes of Reynolds numbers, inlet flow conditions, and building shapes, have been also obtained, respectively. Various results of the present numerical analysis coincide qualitatively well with earlier reported empirical results.

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터널화재시 자연환기에 의한 연기거동에 관한 실험적 연구 (An Experimental Study of Smoke Movement in Tunnel Fires with Natural Ventilation)

  • 김충익;유홍선;이성룡;박현태
    • 설비공학논문집
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    • 제14권3호
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    • pp.247-253
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    • 2002
  • In this study, reduced-scale experiments were conducted to analyze smoke movement in tunnel fire with roof vent. The 1/20 scale experiments were carried out under the Froude scaling using gasoline pool fire ranging from 7.3 to 15.4 cm in diameter with total heat release rate from 1.0 to 8.46kw. In case of 1 m high vent, smoke front reached to the tunnel exit at about 16 sec delayed with ventilation. The delay time grew longer with the vent height. The temperature after the vent was lower than that without the vent. The exit temperature declined maximum of $20^{\circ}C$ after passing the vent. It was confirmed that the thickness of smoke layer was maintained uniformly under the 25% height of the tunnel through the visualized smoke now by a laser sheet and the digital camcorder.

치환환기되는 실내에 있어서 인체주변의 기류 및 온열환경 특성에 대한 검토 (Examination of Airflow and Thermal Environment Characteristic around Human Body in a Room with Displacement Ventilation)

  • 양정훈
    • 설비공학논문집
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    • 제19권4호
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    • pp.299-306
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    • 2007
  • Recently, the numerical analysis using person shape model for CFD (Computational Fluid Dynamic) has been researched widely for the thermal comfort and inhaled air quality of human body in the indoor environments. The purpose of this research is to examine the characteristic of airflow and thermal environment around human body by the experiment of displacement ventilation that assumes the indoor environment of natural convection. In this study, thermal manikin was used instead of real human body. The Airflow characteristic around human body was measured in precision by PIV (Particle Image Velocimetry). This experimental result will be used as data for CFD benchmark test using person shape model.

지하공간의 공기 질 개선을 위한 지하철 터널 내 열차풍의 수치 해석적 연구 (A NUMERICAL ANALYSIS OF TRAIN-WIND IN THE SUBWAY TUNNEL FOR THE IMPROVEMENT OF THE OF UNDERGROUND SPACE AIR QUALITY)

  • 이준호;쥬레바 막슈다;정상현;송동주
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2011년 춘계학술대회논문집
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    • pp.523-528
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    • 2011
  • Subway becomes more and more main transportation in major cities. Air pollution in the subway platforms is decreased; however, dust flow inside subway tunnel and train is increased by installing Platform Screen Door. Airflow inside subway tunnel is observed using computational method in this study The airflow characteristics around ventilation shafts and inside the tunnel is studied following the train movement, while the train moves from existing Miasamgeori station to Gireum station ANSYS CFX V12.0.l and ICEM CFD V12.0.l are used to compute the airflow inside the subway tunnel.

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