• Title/Summary/Keyword: 換氣

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A numerical study on the ventilation characteristics of rainfall in road tunnel (강우변화를 고려한 도로터널의 환기특성에 관한 수치해석)

  • Lee, Ho-Hyung;Lee, Seung-Chul
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.17 no.3
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    • pp.341-351
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    • 2015
  • When rainfall occurred on road tunnel, that is likely to have influence upon ventilation force in the tunnels but the tunnels ventilation system did not consider factors of rainfall. Thus, this study investigated effects of rainfall upon ventilation force in the tunnels at no rainfall and changing of rainfall by 3 dimensional numerical method. Flow rate into road tunnels decreased as many as 52.34% at rainfall of 150 mm/hr, and pressure drop of road tunnel between entrance and exit decreased as many as 22.22%, so that rainfall had influence upon ventilation force in the tunnel. The number of necessary jet fan in road tunnels is 12 at no rainfall but, when rainfall of 80 mm/hr on road tunnels, the number of necessary jet fan in road tunnels is 16, when rainfall of 150 mm/hr on road tunnels, the number of necessary jet fan in road tunnels is 17. So, factor of rainfall should be considered at estimation of ventilation system of road tunnel.

An experimental study on the performance of the separate type heat pipe in accordance with the refrigerant charge (냉매 충진량에 따른 분리형 히트파이프 성능에 관한 실험적 연구)

  • Jeon, Sung-Taek;Cho, Jin-Pyo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.3
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    • pp.1600-1604
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    • 2015
  • As modern houses are constructed with high-density and high-insulation, there is benefit to reduce energy consumption, but there are many side effects raised from polluted air. To solve the problem, a ventilation system is used to improve a indoor air quality. In this research, we experimentally estimate ventilation performance of HRV(heat recovery ventilator) with heat-pipe according to working fluid filling quantity and ventilation. Heat-pipe used in this study was designated separately to be applied to a ventilation system. The working fluid was R22, which was filled from 40 to 55 (%vol.) by 5(%vol.). Ventilation based on the front velocity was measured from 0.3 m/s to 1.5 m/s by 0.3 m/s intervals. Refrigerant filling quantity with the highest efficiency was found to depend on the ventilation. From this study the optimal refrigerant filling quantity in accordance with the ventilation of the detachable heat pipes was found experimentally.

A Study on Fire ventilation design of road tunnel (도로터널에서의 화재환기 설계에 관한 연구)

  • Kim, Myung-Bae;Choi, Byung-Il;Choi, Jun-Seok;Han, Yong-Shik
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.6 no.2
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    • pp.129-139
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    • 2004
  • The several assumptions and design parameters to determine the ventilation rate in tunnel ventilation system were examined. In longitudinal ventilating tunnel, the ventilation rate has been determined by the critical velocity above which the smoke propagation to the upstream of ventilating air is prevented. Based upon the examination of assumptions and experimental results, we suggested the improved method to determine the critical velocity. In transverse ventilating tunnel, we found that the ventilation rate has been determined in accordance with the custom rather than fire-smoke dynamics such as the critical velocity in the longitudinal ventilating tunnel. It is because the ventilation rate in the transverse ventilation system has been determined by considering only the ventilation of contaminant by vehicle. To improve the ventilation design parameters based upon the fire-smoke dynamics, we conducted model tunnel fire experiments. From the experimental results, smoke propagating distance and smoke filling were suggested as the design parameter to determine the ventilation rate in transverse ventilating tunnel. And tunnels in Europe designed by the custom is found to have the dangerous nature in view of fire safety.

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A Study on ventilation characteristics in bidirectional traffic tunnels - focused on the effects of unequal vehicular speed (대면통행 터널의 환기특성 연구 - 양방향 차등차속의 영향분석을 중심으로)

  • Kim, Hyo-Gyu;Song, Seok-Hun;Lee, Chang-Woo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.7 no.1
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    • pp.13-25
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    • 2005
  • In general, tunnel ventilation is analyzed with the assumption of equal vehicular speed for both directions in bidirectional traffic tunnels. This practice is likely to result in minimizing the piston effects and cannot take into consideration the effects of real situations, since in most cases, speeds of vehicles moving in opposite directions are not equal. Therefore, The ultimate goal of this study is to review the effects of unequal vehicular speeds on the planning of local bidirectional tunnel ventilation. To apply unequal vehicular speed for the bidirectional tunnel ventilation plan, the following requirements are necessary; (1) Adoption of strict smoke concentration standards for 'free-flow & congested' traffic conditions, (2) Selection of an appropriate ratio of heavy directional traffic volume, and (3) Selection of reasonable stepwised magnitude of speed difference. Based on the importance of research topic, this study aims at comparing the differences of the capacity of ventilation equipment for the cases with equal and unequal vehicular speeds in local bidirectional tunnels.

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The Study on Relationship of Arousal, Pleasure, and Behavior Intention from a Store Environment: Focused on Moderating Role of Shopping Value (점포환경으로 인한 환기와 즐거움, 행동의도 간의 관계에 대한 연구: 쇼핑 가치에 의한 조절변수를 중심으로)

  • Lee, Jong-Ho;Oxk, Jung-Won;Park, Hyo-Hyun
    • Journal of Distribution Research
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    • v.13 no.4
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    • pp.21-46
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    • 2008
  • The purpose of this study in to investigate the high-arousal has a direct effect on the pleasure. Especially this paper focused on the moderating effect of shopping value(hedonic vs utilitarian). Namely, interaction effect of arousal and shopping value has a direct effect on the pleasure. We also examine the pleasure impact on the behavior intention. The main results of this article are as follow; First, it was proved that high arousal can influence on pleasure. Second, it was also proved the interaction effect of arousal and shopping value can influence on arousal. Third, it was proved the pleasure can have a positive influence on behavior intention.

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A Study on How to Evaluate Appropriate Ventilation Rate of Indoor Facility Handling Hazardous Substances by Their Flammable and Explosive Properties (유해화학물질을 취급하는 실내시설에서의 인화폭발성에 따른 적정 환기량 산정에 대한 연구)

  • Mansu Park;Cheong-Min Seo;Hyo-Soub Yoon;Kyoshik Park
    • Journal of the Society of Disaster Information
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    • v.20 no.2
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    • pp.293-301
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    • 2024
  • Purpose: Ministry of Environment statistics reveals more than 132 fire·explosion accidents in South Korea between 2014 and 2023. Among them, fire and/or explosion accidents are very impactive in their scale and consequence. This study aims to suggest a new method of reasonable way to calculate the ventilation rate of indoor facility handling hazardous chemicals based on their inflammability. Method: A new method to calculate the ventilation rate is based on the physicochemical properties of the chemicals handled, which is more reasonable compared with the current regulation based only on the floor area of the facility. Result: Considering the physicochemical properties, 178 chemicals based on their inflammability were studied and 168(94%) met the criteria for the current regulation. Some materials have been shown to require too much or too little ventilation rate. Conclusion: Through this study, a reasonable method of calculating the required ventilation rate was proposed. This should be applied to ensure the safety of workers to deal chemicals.

선박의 환기구가 연기확산에 미치는 영향에 대한 수치적 연구

  • Kim, Won-Uk
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2013.10a
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    • pp.24-26
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    • 2013
  • 이 연구에서는 선박의 환기구가 화재 발생시 선박승무원의 인명안전에 미치는 영향에 대하여 분석하고자 한다. 분석 기법은 CFD을 이용한 화재시뮬레이션이다. 향후 이 분석 결과를 이용하여 선박승무원의 생존율 향상에 필요한 여러 가지 조건 중 하나로 사용될 수 있을 것으로 본다.

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