• Title/Summary/Keyword: 공기류

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에테르류에 대한 연소열을 이용한 폭발하한계 추산

  • 최용찬;하동명
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • 2001.11a
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    • pp.387-392
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    • 2001
  • 공정에서 가연성물질을 취급함에 있어 밸브의 조작실수, 배관접합부파손 등으로 인해 주위에 공기와 혼합되면 화재 및 폭발이 발생할 수도 있으며, 또한 유해물질이 유출되는 경우도 있다. 산업현장에서 화재 및 폭발의 위험을 최소화하기 위해서는 공정의 안전과 최적화 조작이 이루어 져야 하는데, 이를 위해 우선 작업 조건 하에서 취급물질의 연소 특성치 파악이 필요하다/sup 1)/.(중략)

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공기조화실비의 커미셔닝 수행절차

  • 김두성;김천용
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.30 no.8
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    • pp.9-23
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    • 2001
  • 공조설비의 품질확보를 위한 커미셔닝이 국내에서도 도입단계에 있으나 이를 수행하는 절차와 방법에 대한 구체적인 기준이 마련되지 않아 수행에 어려움이 많은 실정이다 본고에서는 최근 수행한 경험을 바탕으로 수행에 따르는 절차와 필요한서류 등을 간단하게 기술하였다.

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Competitive Advantage Strategy of Construction Duration by SWOT Analysis (SWOT 분석을 통한 건설기업의 공기경쟁력 강화 전략)

  • Kim, Sun-Kuk;Lee, Hyun-Soo;Ryu, Han-Guk
    • Korean Journal of Construction Engineering and Management
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    • v.7 no.2 s.30
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    • pp.109-117
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    • 2006
  • Recent rapid changes such as construction market reduction, lowest bidding system of construction cost, five days per week system, and post-construction sale system are inevitably accelerating the competitiveness between construction companies. Those rapid changes of construction environment require construction companies, which are main participants of construction industry, to adapt to the changes and more to lead new construction environment. However, there are many construction uncertainties which could delay construction completion. Without the proper identification of construction uncertainties, structured strategy establishment and management of construction schedule, the competitive advantages of construction duration could not be made. Thus this paper limited the research boundary to construction duration competitiveness instead of general strategy establishment. Recognizing the importance of proper calculation of construction duration, requirements of construction duration reduction and limited researches related to construction schedule strategy, we established the 25 strategies for construction duration competitivenss by internal and external construction environment analysis and SWOT analysis, and then elicited the first considerations to accomplish the strategies through concensus of all the staffs by questionnaire, brainstroming and face-to-face interviews.

Oscillating Flow Field Analysis as Shape of Air Chamber in OWC-type Wave Energy Conversion (OWC형 파력발전장치 공기실 형상에 따른 왕복유동장 해석)

  • Hong, Key-Yong;Shin, Seung-Ho;Hyun, Beom-Soo;Ryu, Hwang-Jin;Park, Soon-Jong;Moon, Jae-Seung
    • Journal of Navigation and Port Research
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    • v.31 no.1 s.117
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    • pp.29-33
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    • 2007
  • An OWC-type Wave Energy Conversion passes through 3 steps energy conversion process. This paper deal with the internal oscillating flow and effect of shape of air chamber and duct at setting place of turbine by numerical analysis using commercial CFD code, FLUENT. Air chamber and duct in OWC-type wave energy conversion are adopting sudden expanded and contracted form for high-efficiency. So, whole oscillating flow from OWC-type chamber to outlet duct through duct was solved by steady and unsteady analysis in order that flow efficiency of air chamber and duct was made better.

Electrochemical properties of AZ31, AZ61 magnesium alloy electrodes for eco-friendly Magnesium-air battery (친환경 마그네슘-공기 전지용 AZ31, AZ61 마그네슘 합금 전극의 전기화학적 특성)

  • Choi, Weon-Kyung
    • Journal of the Korea Convergence Society
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    • v.12 no.5
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    • pp.17-22
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    • 2021
  • Eco-friendly magnesium-air battery is a kind of metal-air battery known as a primary battery with a very high theoretical discharge capacity. This battery is also called a metal-fuel cell from the viewpoint of using oxygen in the atmosphere as a cathode active material and magnesium alloy as a fuel. Since battery performance is determined by the properties of the magnesium alloy used as a anode, more research and development of the magnesium alloy electrode as a anode material are required in order to commercialize it as a high-performance battery. In this study, the commercialized magnesium alloys(AZ31, AZ61) were selected and then electrochemical measurements and discharge test were conducted. Electrochemical properties of magnesium alloys were investigated by OCP changes, Tafel parameters and CV measurement, and the feasibilities of AZ61 alloy with excellent discharge capacity(1410mAhg-1) as electrode materials were evaluated through CC discharge experiments.

Ground Air Heat Exchanger Design and Analysis for Air Source Heat Pump (공기열원 히트펌프를 위한 공기식 지중 열교환기(GAHX) 설계 및 분석 연구)

  • Lee, Kwang-Seob;Lyu, Nam-Jin;Kang, Eun-Chul;Lee, Euy-Joon
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.12 no.2
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    • pp.1-6
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    • 2016
  • A ground air heat exchanger (GAHX), also called earth air heat exchanger is a useful technology to be integrated with other renewable energy technologies. In this study, ground-air heat exchanger system for the air source heat pump is introduced. The purpose of this study is to design the volumetric flow rate and the length of GAHX system. A GAHX length model equation has been developed and used for calculation. GAHX thermal efficiency are recommended as 75% and 85% in order to optimize pipe length. $2,750m^3/h$, $2,420m^3/h$ of volumetric flow rate on 88.3m, 111.7m length are suggested for providing 7.5kW thermal capacity. And the number of path is recommended more than two to minimize pressure drop. For future study, advanced model equation study with ground thermal behavior and a more efficient GAHX design will be considered.