• 터널과지하공간
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• 제27권4호
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• pp.217-229
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• 2017

최근 국내의 탄광들은 오랜 가행으로 작업심도가 깊어지고 운행갱도가 길어지면서 지열에 의한 온도증가로 인하여 작업환경이 더욱 악화되고 있다. 갱내의 작업환경 개선을 위하여 A광업소를 대상으로 통기평가를 하였으며 갱내의 통기 효율을 증가시키기 위하여 통기전용수갱을 건설할 시에 온도 예측 프로그램인 CLIMSIM을 이용하여 온도에 대한 효과를 수치 해석하였다. A광업소의 필요 공기량은 $6,152m^3/min$으로 산출되었으며, 실제 총 입기량은 $4,710m^3/min$로 공기량이 $1,442m^3/min$ 부족한 것으로 나타났다. -395 ML에서 -488 ML까지 93 m 길이의 통기전용수갱을 건설하였을 시에 -488 ML 작업장의 온도가 현재보다 약 $3^{\circ}C$가 감소되었다. 인공신경망을 이용하여 -523 ML 개발시의 $CO_2$ 용출을 예측한 결과 채탄량과 탄층 두께가 증가할수록 $CO_2$의 발생량은 증가하였다. $CO_2$ 발생량에 가장 큰 영향을 주는 인자는 탄층 두께와 채탄량으로 나타났으며 통기량이 증가할수록 이산화탄소의 농도 저하에 큰 영향을 미치는 것으로 나타났다.

• 설비공학논문집
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• 제15권8호
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• pp.630-640
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• 2003

As tunnel ventilation has recently been playing a major role in the tunnel construction and maintenance, longitudinal ventilation systems with jet fans have been utilized a great deal because they are economical and effective. However, due to the length of tunnels and heavy traffic, it is hard to take the field measurements. In this study, therefore, the computer simulation and the model experiment of producing a wind tunnel were carried out simultaneously and the results were compared. The ultimate objective of this research was to interpret the air flow pattern inside the tunnel with a jet-fan was set up, and to offer the useful data for jet-fan installation and operation. The experiment was carried out with varying the jet-fan diameters, location of installation, the discharge velocity. Result showed that as the initial static pressure came up with the negative pressure, the tunnel air flowed into the inside of tunnel from outside due to the entrainment-effect and the backflow-phenomenon by separation-effect was observed in the lower half part of the tunnel. As the jet-fan was getting closer to the tunnel wall, the entrainment-effect caused by the interaction with the wall was increased; however, the mixing distance and irregular flow section became longer, and also the air pressure loss generated by wall friction was large.

• 한국터널지하공간학회 논문집
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• 제21권6호
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• pp.749-762
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• 2019

최근 들어 대도시의 교통난 해소 및 녹지공간 확보를 위해서 도로의 지하화가 추진되고 있으며, 대형차 혼입률이 낮기 때문에 소형차 전용 도로터널로 계획되거나 건설되고 있다. 또한, 도시에 건설되고 있는 터널은 간선도로의 기능을 수행하기 위해서 장대화되는 추세이다. 따라서 환기시스템의 용량이 증대하고 다양한 환기방식이 요구되고 있으며, 환기기 운전비용 등 터널준공 후, 유지관리의 중요성이 부각되게 되었다. 따라서 환기기 소비전력의 절감을 위한 운전단계의 최적화나 환기기 운전제어로직에 대한 연구의 필요성이 증대하고 있는 실정이다. 본 연구에서는 소형차 전용도로 터널에 ① 제트팬방식과 조합환기방식, ② 제트팬 + 공기정화방식, ③ 제트팬 + 수직갱방식, ④ 제트팬 + 급기반횡류환기방식을 적용하여 에너지 절약적인 환기기 운전을 실현하기 위해서 운전단계 및 제어로직 최적화 방안의 필요성에 대한 연구를 수행하였다. 연구의 결과로 조합환기방식의 터널의 경우, 다양한 운전조합이 있을 수 있으며, 발생되는 환기량이 동일할 지라도 운전조합에 따라 소요동력이 크게 차이가 나며, 일반적으로 수행하고 있는 제트팬 우선 운전방식보다는 축류팬을 우선 운전하는 것이 동력절감에 효과가 있는 것으로 나타났다.

• 한국터널지하공간학회 논문집
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• 제20권1호
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• pp.39-53
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• 2018

일반적으로 터널 내 총환기저항계수는 입출구 손실계수, 벽면마찰계수 그리고 급격한 확대나 축소단면 등에 의해 발생하는 부차적 손실계수의 총합으로 구성된다. 개통 전 터널의 경우는 가동 중인 환기팬을 중단하게 되면, 터널 내 풍속은 총환기저항력에 의해 감소하는 현상이 나타난다. 즉, 속도감쇄법은 개통 전 터널에서 비교적 안정적이면서도 손쉽게 터널 내 벽면마찰계수를 추정하는 방법이다. 그러나 기존의 선행연구에서 환기팬의 가동을 중단 후 수렴되는 풍속이 음수일 경우는 속도감쇄법에 따른 벽면마찰계수의 추정이 곤란한 특성이 있다. 반면 교통환기력이 작용하는 공용 중인 터널에서는 좀더 복잡한 과정을 거치지만, 합리적인 벽면마찰계수를 추정할 수 있다. 본 연구에서는 교통환기력의 측정변수를 최소화할 수 있는 방법을 제안하였고, 공용 중 터널에 적용할 수 있는 방법을 고찰하였다. 또한 환기팬 정지 후 터널 내 풍속이 감소하는 동안에 외부 자연풍의 급격한 변화가 발생하여도 교통환기력이 일정할 경우에 대하여, 교통환기력의 증분을 계산할 수 있는 방법과 터널 내 벽면마찰계수를 추정할 수 있도록 동적 시뮬레이션이 가능한 프로그램 로직을 개발하였다.

• 한국대기환경학회지
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• 제30권3호
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• pp.245-250
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• 2014

As the number of nursery facilities and infants who stay there is continuously increasing, IAQ (Indoor Air Quality) of nursery facilities should be managed strictly and thoroughly because infants are more susceptible to infections due to their low resistivity. In this study the characteristics of IAQ and ventilation associated factors were investigaed for suggesting a desirable condition for IAQ management. Environmental factors were not much related to IAQ characteristics rather than internal factors such as structures of the room. And the positive effect of ventilation on IAQ was obvious and seemed to hinge on factors related to window area especially window/wall ratio. Results of this study indicate that the structure with broader window area of a room and frequnet ventilation can be an effective way for keeping IAQ of nursery facilities clean and safe.

• 수산해양교육연구
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• 제21권2호
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• pp.269-277
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• 2009

Ventilation equipment performs a central role to maintain comfort subway environment. So ventilation equipment of Busan subway line No.1 is required to improve thermal environment. In this study, conditions of thermal environment are presented to improve ventilation equipment at existing subway station platforms by measuring thermal environment of platforms operated ventilation equipment at 14 stations of Busan subway line No.1. AWS of data in comparison with the neighbouring platforms and thermal environment analysis. Thermal environment status of subway platform analysis results are as follows. 1)Daytime platform temperature was higher than outdoor temperature, but night time platform temperature was lower than outdoor temperature. 2)Train wind had effect on improving thermal comfort in platform. 3)When outdoor temperature is below $24^{\circ}C$, inlet air is able to lower than platform temperature. 4)Considering existing ventilation system, night purge systems is useful to improving platform thermal environment.

• 토지주택연구
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• 제10권1호
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• pp.25-32
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• 2019

In this study, the case analysis data on underground temperature are presented. In addition, numerical analysis of the ventilation load reduction plan was derived according to the residence schedule change for the building with cool tube. The research scope and method are as follows. The overall system principle was examined through reviewing the theory of the Cool tube system. Case study and analysis were conducted. Numerical simulation was used to examine the change in energy usage. Also, the change of load energy in case of varying amount of ventilation was derived based on actual building room schedule. When the Cool tube system was applied to the residential buildings, the cooling load was reduced from 3,331 kW to 193 kW, which showed a reduction effect of about 90%.The heating load was reduced from 42,276kW to 32,575kW by 23%.Also, result shows that the cooling load decreased by 24% and the heating load decreased by 66% when the number of ventilation according to the occupancy schedule was applied.

• Journal of Plant Biotechnology
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• 제30권2호
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• pp.173-177
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• 2003

The effect of IBA and NAA on adventitious root cultures of Panax ginseng C.A. Mater were investigated. Results indicated differences in growth and development of the roots according to 5mg/L IBA and 2mg/L NAA. IBA resulted in a normal root development and a higher growth compared to NAA. The roots formed on NAA-containing media were shorter and thicker than those in IBA, showing a hypertrophy of the root tip. NAA induced more than 1.6 times higher ethylene production compared to IBA, which caused inhibition of the root growth. Under the ventilation, in the other hand, on difference was observed in ethylene concentration and the root growth between IBA and NAA treatments. Under ventilation ethylene production was not detected until 10 days of culture, while detected from the initial stage under on ventilation. The results suggested the importance of ventilation during the culture for the growth and development of ginseng adventitious roots.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.965-968
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• 2007

Two major parameters, i.e. carbon dioxide ($CO_2$) and particulate matters smaller than $10{\mu}m\;(PM_{10})$, were selected as the index pollutants in managing indoor air quality. The former pollutant, $CO_2$, is the index that shows the ventilation status and is exhaled by passengers when they breathe in train or subway. It is generally known that high $CO_2$ concentration in the vehicle may be decreased by insufficient air-tightening vehicle bodies and the air is ventilated when vehicles stop at the station and doors open. However, there is no established proof or quantitatively identified data on how much the $CO_2$ concentration is reduced when ventilation is done while doors are opened. In this study, $CO_2$ concentrations were measured in 6 lines of Korail and one line of Seoul Metro subway linesand a theoretical approach was takento predict the changing trend of $CO_2$ concentrations during the operation of vehicle by using $CO_2$ dilution factor through natural ventilation. As a result, the change could be quantified and it was found that app. 35% of indoor $CO_2$ was removed through natural ventilation.

• 항공우주시스템공학회지
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• 제8권1호
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• pp.30-35
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• 2014

This study has been conducted to develop an ejector system applied in the aircraft engine-bay ventilation system. Tandem-Ejector was selected as a component of ventilation system because it could achieve high ventilation performance in spite of motive flow with small flow rate. Tandem-Ejector is composed of a primary nozzle and two mixing ducts ($1^{st}$ mixing duct and $2^{nd}$ mixing duct). In this study, 1-D Tandem-Ejector model has been built with conservation laws and isentropic relation for 1-D ejector sizing and performance prediction. Computational Fluid Dynamics(CFD) has been conducted to investigate ejector performance and flow characteristics in the ejector. Also, Tandem-Ejector performance tests have been conducted to obtain ejector pumping performance and to investigate stand-off (gap between primary nozzle and $1^{st}$ mixing duct inlet) effect on ejector pumping performance.