• Title/Summary/Keyword: 공기령

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Case Study of the Longest Roadway Tunnel in Korea, Baehuryeong Tunnel (국내 최장대 양방향 도로터널 설계사례-배후령터널)

  • Lee Seon-Bok;Je Hae-Chan
    • Tunnel and Underground Space
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    • v.15 no.6 s.59
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    • pp.432-440
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    • 2005
  • Baehuryeong tunnel connects Chuncheon with Hwacheon in Kangwon, Korea, This tunnel is a single tunnel with 5,057 m long and two bidirectional lanes which will be extended into low lanes in the future. The estimated construction period of Baehuryeong tunnel is approximately 55 months. This tunnel will become the longest bidirectional roadway tunnel in Korea. Compared to a twin tunnel, a bidirectional single tunnel has two major disadvantages with regard to the ventilation system and ease of escape during fire. For these reasons, a service tunnel and the transverse ventilation system are planned first time in Korea. In case of fire, the tunnel ventilation design aims to maintain a smoke free layer for passenger evacuation. The geology of Baehuryeong tunnel site is mainly composed of gneiss and granite. Baehuryeong fault is a mainly large scale fault which stands vertical and parallels with tunnel direction. The influenced zone of this fault is within 70 m. Baehuryeong tunnel was designed that it was separated with the distance of more than 100 m from Baehuryeong fault for its safety.

Environmental Prediction in Greenhouse According to Modified Greenhouse Structure and Heat Exchanger Location for Efficient Thermal Energy Management (효율적인 열에너지 관리를 위한 온실 형상 및 열 교환 장치 위치 개선에 따른 온실 내부 환경 예측)

  • Jeong, In Seon;Lee, Chung Geon;Cho, La Hoon;Park, Sun Yong;Kim, Seok Jun;Kim, Dae Hyun;Oh, Jae-Heun
    • Journal of Bio-Environment Control
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    • v.30 no.4
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    • pp.278-286
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    • 2021
  • In this study, based on the Computational Fluid Dynamics (CFD) simulation model developed through previous study, inner environmenct of the modified glass greenhouse was predicted. Also, suggested the optimal shape of the greenhouse and location of the heat exchangers for heat energy management of the greenhouse using the developed model. For efficient heating energy management, the glass greenhouse was modified by changing the cross-section design and the location of the heat exchanger. The optimal cross-section design was selected based on the cross-section design standard of Republic of Korea's glass greenhouse, and the Fan Coil Unit(FCU) and the radiating pipe were re-positioned based on "Standard of greenhouse environment design" to enhance energy saving efficiency. The simulation analysis was performed to predict the inner temperature distribution and heat transfer with the modified greenhouse structure using the developed inner environment prediction model. As a result of simulation, the mean temperature and uniformity of the modified greenhouse were 0.65℃, 0.75%p higher than those of the control greenhouse, respectively. Also, the maximum deviation decreased by an average of 0.25℃. And the mean age of air was 18 sec. lower than that of the control greenhouse. It was confirmed that efficient heating energy management was possible in the modified greenhouse, when considered the temperature uniformity and the ventilation performance.

A Study on Ventilation Characteristics Made by Thin Line Type Ventilator in an Apartment House (창호형 환기장치에 의한 아파트의 환기성능에 대한 연구)

  • Chang, Hyun-Jae;Kim, Hyung-Jin
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.23 no.3
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    • pp.201-207
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    • 2011
  • Total heat recovery type ventilators that are connected to each room with ducts are mainly installed in Korea, but they raise concern over duct pollution. In this study, indoor environments made by thin line type ventilators installed in dwelling units of apartment houses are investigated by CFD. Results show the case that thin line type ventilators installed in each room-including kitchens-make the best indoor environment that maintains air velocity at under 0.25m/s, and evenly distributes the age of air in all areas.

Analysis of the Local Air-Change Effectiveness by Field Measurement (실험을 통한 환기시스템의 국소적 환기효율 분석)

  • Choi, Younhee;Song, Doosam
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.29 no.2
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    • pp.63-67
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    • 2017
  • The purpose of this study is to analyze the Age of Air and the Local Air-change Effectiveness of by field measurement. The indexes of Age of Air and Local Air-change Effectiveness are used to analyze the local ventilation effectiveness of multiple locations and are mainly evaluated using the computational fluid dynamics (CFD) method. In this study, measurement of the Local Air-change Effectiveness was based on ASHRAE 129. The performance of Local Air-change Effectiveness and the dependence of the outlet location on Local Air-change Effectiveness were analyzed. The results showed that a greater air-change rate (ACH) may not guarantee better local ventilation effectiveness.

The study of external flow around building using CFD (CFD를 이용한 건축물 외부유동 특성에 관한 연구)

  • Lee, Sang-Seok;Lee, Myeong-Yong;Lee, Ji-Hong;Lee, Jin-Seok;Lee, Do-Hyung;Jin, Bong-Yong
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.61-66
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    • 2008
  • Recently a certain level is required in natural ventilation for improving on the 'quality' aspect in housing. It is simulated the external flow around building which affact natural ventilation using CFD. Natural ventilation is estimated on the specific household which considered topography and not considered.

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Study on Ventilation Performance of Multi-room in Apartment - Airflow and Ventilation Effectiveness in Multi-room - (공동주택의 환기방식별 다수실 환기 성능에 관한 연구 - 다수실의 환기경로 및 환기효율 -)

  • Kwon, Kyung-Woo;Cho, Si-Jin;Choi, Eui-Sung;Park, Jun-Seok
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.399-404
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    • 2006
  • Heating and cooling load of ventilation is a very important part of building energy saving. Improving ventilation effectiveness can save building energy consume and supply fresh air to indoor efficiently. So this study measured mulity-zone aiflow and ventilation effectiveness according to ventilation types. Result of measurement show that ventilation effectiveness is depends on ventilation system design rather than ventilation types.

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A Study on The Performance of Ventilation and Thermal Environment for a Combined Type Diffuser in a Residential Space (거주공간에 대한 급·배기 일체형 디퓨저의 환기 및 온열환경 유지성능에 대한 연구)

  • Lim, Seok-Young;Chang, Hyun-Jae
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.29 no.2
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    • pp.74-81
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    • 2017
  • In this study, the combined-type diffuser developed by the Authors, in a previous study, was applied to a residential space. The performance of a ventilation and thermal environment, created by the use of a combined-type diffuser was compared to the pan-type diffuser widely used in apartment houses. In cooling conditions, because of the relatively high air flow rate of ceiling cassette-type air conditioners, the characteristics of airflow distribution in a room were governed by the air conditioner's airflow. In heating conditions, because of the low air flow rate of the diffuser, the characteristics of airflow distribution were governed by the buoyancy effect created by cold external walls and a hot floor. In terms of the Air Diffusion Performance Index (ADPI), which is a thermal environmental index, the result of a combined-type diffuser was greater than a pan-type diffuser in both of cooling and heating conditions. Consequently, the combined-type diffuser showed equal or superior ventilation and thermal environment performance compared to a pan-type diffuser.