• Title/Summary/Keyword: 기류특성

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A Study on Response Characteristics of ionization Smoke Detector Influenced by Air Stream (이온화식 연기감지기의 기류응답특성 연구)

  • 이복영;정길순;이병곤
    • Fire Science and Engineering
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    • v.17 no.2
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    • pp.6-9
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    • 2003
  • Recently, forced ventilating air conditioning system has been widely used in modern buildings. However, It is obvious that this kind of system may affect on the response of fire detectors at real fire incidents, especially, on the ionization smoke detector, which is critically influenced by air stream. Therefore we studied to verify the response characteristics of air stream by ionization smoke detector for the design of facilities in practice. In this study, experiments were executed to examine the correlation between air velocity and the ionization detector's responses with var-ious air velocity and smoke densities in the simulated test room. As a result of experiments, ionization detector's operating time is in reverse proportion to air velocity. And the detector shows more sensitive reaction when the velocity of smoke stream increase over 60 cm/s. In addition, it was shown that ionization smoke detector is more sensitive to smoldering fires in paper than that in petro-chemicals.

북동기류 유입시 목포지방 최고기온 특성 분석

  • Woo, Jong-Taek;Ryu, Chan-Su
    • 한국데이터정보과학회:학술대회논문집
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    • 2003.10a
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    • pp.129-137
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    • 2003
  • 최근 30년간(1071-2000) 북동기류 유입시 목포지방 최고기온의 예측을 위하여 북동기류 유입시 통계적 특성을 분석하였다. 분석 내용은 최대풍향 발생빈도, 최고기온 및 풍속, 풍속별 최고기온, 전일 최고기온과 교차분석, 풍속별 최고기온 분석 및 전운량(하늘상태) 분석 등이다. 분석결과 계절에 따라 변화는 있으나 북동기류의 유입으로 인한 기온의 변화 경향에 몇 가지 특성을 발견할 수 있었다.

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A Study on the Development of Circuit Breaker Testing System (차단기 특성 시험 시스템의 개발에 관한 연구)

  • Kim, Dong-Su;Won, Ho-Sung;Kim, Chul-Hwan
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.650_651
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    • 2009
  • 현재 한국전기연구원에서는 년간 약 1,000여대 이상의 차단기류에 대하여 사용전 검사 시험을 실시하고 있다. 차단기류의 사용전 검사 시험 항목은 개폐 특성에 대한 검증이 주를 이룬다. 현재 사용하고 있는 차단기 개폐특성 시험 설비는 약 20여년을 사용하여 보수가 필요한 시점에 도달하였다. 본 논문에서는 차단기류의 개폐특성 시험에 사용하던 차단기 특성 시험 시스템의 단점을 보완하여 시험의 신뢰성 및 사용자 편의성을 향상시킨 시험 시스템을 개발하고자 한다.

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Respiratory flow measurement system (호흡 기류 계측 시스템의 개발)

  • Cha, Eun-Jong;Lee, Tae-Soo;Goo, Yong-Sook
    • Proceedings of the KOSOMBE Conference
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    • v.1995 no.05
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    • pp.64-67
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    • 1995
  • 전산화폐활량계를 국산화하기 위하여 호흡기류 계측시스템을 개발하였다. 호흡기류를 측정하는 방법으로 Pneumotachography를 적용하였다. 자체 Pneumotachometer를 설계, 제작하였고, 증폭기와 필터를 통하여 0 - 5 V 범위의 기류신호가 출력되도록 하였다. 온도보정을 위하여 기류의 온도를 K-type 열전쌍으로 연속측정하여 보정신호를 역시 0 - 5 V 범위로 제공하도록 제작하였으며 따라서 온도에 따른 측정오차를 근본적으로 제거하였다. 피검자의 감염 가능성을 최소화하기 위하여 환기기구를 사용하였으며 전력소모가 적고 미세균의 제거가 가능하다. 본 시스템의 특성 측정 결과 충분히 우수한 정특성과 동특성을 얻었으며 현재 호흡기류를 정량분석하는 S/W-시스템을 개발중이다.

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Accuracy Evaluation of Respiratory Air Flow Transducer for Artificial Ventilation (인공호흡시 호흡기류 계측 센서의 정확도 평가)

  • Lee, In-Kwang;Park, Mi-Jung;Kim, Kyoung-Ok;Shin, Eun-Young;Shon, Ho-Sun;Cha, Eun-Jong;Kim, Kyung-Ah
    • Journal of the Korean Society of Radiology
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    • v.9 no.7
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    • pp.425-431
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    • 2015
  • Measurement accuracy was evaluated for the respiratory air flow transducer developed for applications under emergent situations. Pressure-Flow calibration equation was obtained by acquisition of air flow signals from the transducer in response to 6 flow waveforms, similar to those of artificial ventilation, generated by the standard flow generator system. Tidal volume and maximal flow rate were calculated on the flow signal then compared with the error-free data obtained by the linear displacement transducer of the flow generator system. Mean relative error of the tidal volume was within 3% and that of the maximal flow rate, approximately 5%, demonstrating accurate enough measurements. Therefore, the transducer could be applied to emergent situations to monitor the respiratory air flow signal as well as diagnostic parameters in real time.

Experimental Study on Features of Air Egress Velocity in Vestibule Pressurization System (특별피난계단 부속실 제연설비의 방연풍속 기류특성에 관한 실험적 연구)

  • Ryu, Sung-Ho;Lee, Su-Kyung;Hong, Dae-Hwa;Yoon, Myong-O;Choi, Keum-Ran;Park, Jae-Hyun
    • Fire Science and Engineering
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    • v.24 no.5
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    • pp.79-86
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    • 2010
  • In this study, we confirmed the fact that air egress velocity of pressure differential system which is installed in vestibule of smokeproof stairway in domestic high-rise building becomes back-flow into the vestibule not into the livingroom when the doors open to escape in case of fire by actual measurement. It concerned that fire smoke inflow into the vestibule of smokeproof stairway. so, reflux symptoms were developing the condition does not occur by creating an area of $2m^2$ and a model. if it‘s area is less, airflow in upper area was severely reflux. in the case upward 45 gradient of supply damper’s angle of blade, The results that reflux symptoms include upper door but bottom has some reflux. also vestibule of smokeproof stairway‘s area of $4m^2$ in the living room door in the direction of the flow distributon was normal. if a vestibule of smokeproof stairway is smaller, it designed to be performance-based design should be.

Characteristics of Air Egress Velocity in Vestibule Pressurization System Using the Fire Dynamics Simulator (FDS를 이용한 특별피난계단 부속실 제연설비의 방연풍속 기류특성)

  • Ryu, Sung-Ho;Lee, Su-Kyung;Hong, Dae-Hwa;Choi, Keum-Ran
    • Fire Science and Engineering
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    • v.24 no.6
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    • pp.153-159
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    • 2010
  • In this study, we confirmed the fact that air egress velocity of pressure differential system installed at vestibule of smokeproof stairway in domestic high-rise building becomes back-flow to stair-lobby at upper vestibule. Rather it do not back-flow to the livingroom. when fire occur and the door opens to escape from fire zone. so we carry out actual and computational fluid dynamics measurement. In the case upward 45 gradient of supply damper's blade, The simulation results that air flow of upper vestible is steady but back-flow phenomenon occurred at the bottom. However, in the case of $4m^2$, direction of the flow was ideal to living room. If a vestibule’s area is smaller, it must be designed and built according to performance-based design.

Aerodynamic Characteristics of Young and Elderly Adult Patients with Voice Disorders during Continuous Speech (젊은 성인 및 노인 음성장애 환자의 연속발화시 공기역학적 특성 비교)

  • Pyo, Hwa-young
    • The Journal of the Korea Contents Association
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    • v.19 no.12
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    • pp.270-278
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    • 2019
  • This study was performed to compare the aerodynamic characteristics of young and elderly adult male patients with voice disorders during continuous speech. Aerodynamic measurements were obtained after 12 young male patients and 9 elderly male patients read a paragraph. The elderly group showed longer duration, lower airflow rate and air volume than the younger group, but the differences were not significant except phonation time. So, when interpreting the meaning of aerodynamic measures of elderly voice disorder patients in the aspects of airflow and air volume, it should take into account various conditions(e. g. reading materials, pulmonary functions) as well as age.

Applications of tracer gas method for ventilation experiments (환기실험을 일한 추적가스 방법의 응용)

  • 한화택
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.28 no.6
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    • pp.452-462
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    • 1999
  • 환기란 실내에 기류분포를 형성함으로써 발생된 오염물질을 제거하고 재실자에게 신선외기를 공급하기 위한 것이다. 실내의 오염농도는 오염 발생원의 특성과 실내의 환기상태에 의하여 결정되며 환기상태는 실내의 기류분포에 의하여 결정된다. 건축물에서 수행되고 있는 각종 오염물질에 대한 농도측정 실험은 환기의 결과로서 나타나는 실내오염의 정도를 파악하기 위한 것으로 환기의 성능 자체를 측정하기 위한 것이 아니다. 또한 실내의 기류속도 측정실험을 통하여 환기상태를 간접적으로 파악할 수 있으나 정량적인 환기 상태를 측정하지는 못한다. 단순히 기류속도가 크고 작음에 따라서 환기상태의 좋고 나쁨을 표현할 수 없기 때문이다. 그림 1은 이와 같은 환기실험에 관련된 3단계의 실험 종류와 이들 간의 상호 상관관계를 보이고 있다.

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

  • Yang, Jeong-Hoon
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.4
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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.