• Title/Summary/Keyword: Underground air

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Study on Particulate Pollutant Reduction Characteristics of Vegetation Biofilters in Underground Subway Stations (지하역사내 식생바이오필터의 입자상 오염물질 저감특성 연구)

  • Kim, Tae Han;Oh, Ji Eun;Kim, Mi Ju
    • Journal of the Semiconductor & Display Technology
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    • v.21 no.4
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    • pp.99-105
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    • 2022
  • Public attention to the indoor environment of underground subway stations, which is a representative multi-use facility, has been increasing along with the increase in indoor activities. In underground stations, fine iron oxide, which affects the health of users, is generated because of the friction between wheels and rails. Among particulate pollutant reduction technologies, plants have been considered as a non-chemical air purification method, and their effects in reducing certain chemical species have been identified in previous studies. The present study aimed to derive the total quantitative and qualitative reduction effects of a bio-filter system comprising air purifying plants, installed in an underground subway station. The experiment proceeded in two ways. First, PM(particulate matter) reduction effect by vegetation biofilter was monitored with the IAQ(indoor air quality) station. In addition, chemical speciation analysis conducted on the samples collected from the experimental and control areas where plants and irrigation using SEM-EDS(scanning electron microscopy-energy dispersive X-ray spectroscopy). This study confirmed the effect of the vegetation bio-filter system in reducing the accumulation of particulate pollutants and transition and other metals that are harmful to the human body.

Thermodynamic Energy Balance Analysis of Underground Lined Rock Caverns (LRC) for Compressed Air Energy Storage (CAES) (복공식 지하 압축공기에너지 저장공동의 열역학적 에너지수지 분석)

  • Kim, Hyung-Mok;Park, Do-Hyun;Ryu, Dong-Woo;Choi, Byung-Hee;Song, Won-Kyong
    • Tunnel and Underground Space
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    • v.21 no.4
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    • pp.297-306
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    • 2011
  • In this paper, we performed thermodynamic energy balance analysis of the underground lined rock cavern for compressed air energy storage (CAES) using the results of multi-phase heat flow analysis to simulate complex groundwater-compressed air flow around the cavern as well as heat transfer to concrete linings and surrounding rock mass. Our energy balance analysis demonstrated that the energy loss for a daily compression and decompression cycle predominantly depends on the energy loss by heat conduction to the concrete linings and surrounding rock mass for a sufficiently air-tight system with low permeability of the concrete linings. Overall energy efficiency of the underground lined rock caverns for CAES was sensitive to air injection temperature, and the energy loss by heat conduction can be minimized by keeping the air injection temperature closer to the ambient temperature of the surroundings. In such a case, almost all the heat loss during compression phase was gained back in a subsequent decompression phase. Meanwhile, the influence of heat conductivity of the concrete linings to energy efficiency was negligible.

The Effect of Ventilation and Concentration of Indoor Air Quality at Indoor Parking Lots (실내주차장의 실내공기질 농도특성 및 환기에 의한 저감효과)

  • Park, Jeong-Ho
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.20 no.4
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    • pp.241-247
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    • 2010
  • Recently, indoor air quality (IAQ) has been one of the major concerns of people. Indoor parking lots are subject to be exposed to high concentrations of air pollutants emitted from vehicles. This study was performed to investigate indoor air quality (IAQ) at indoor parking lots. Sampling sites were selected 5 indoor parking lots. Target indoor air quality parameters include a number of criteria pollutants such PM$_{10}$, CO, CO$_2$, and HCHO. In addition, a variation of IAQ according to ventilation system operating was measured at C site (underground parking lot). In general, all pollutants were maintained below indoor air quality maintenance standards. The indoor air quality at indoor parking lots was affected by the availability of the ventilation facility and their operation frequency. At the underground parking lot (C site) with ventilation system, TVOC concentration according to ventilation system operating were found to be lower operating (488.2 ${\mu}g/m^3$) than non-operating (1,401.2 ${\mu}g/m^3$).

The Factors Governing Envlronment and Safety in Underground Spaces (지하공간의 환경 및 안전관리 요소)

  • 김복윤
    • Proceedings of the Korean Geotechical Society Conference
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    • 1993.10b
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    • pp.133-162
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    • 1993
  • The environment of underground spaces might be considered in view of working environment during the construction and living environment after completion of the construction work. For controlling environment of underground space, an appropriate measures have to be taken on the governing factors such as air flow, dust, gases, heat, radiation, noise, illumination and water. The more critical matter, in underground environmental point of view, is underground disasters such as fire, gas explosion and water inrush. This paper presents the general introduction of these factors mentioned above and some outcomes of research works as of now.

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An Experimental Study on the Operating Characteristics with HVAC Type of Shopping Center in Underground Passage (지하도상가의 HVAC 구성방식에 따른 운전특성 연구)

  • Lee, Hong-Cheol;Hwang, In-Ju
    • Proceedings of the SAREK Conference
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    • 2007.11a
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    • pp.76-81
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    • 2007
  • The shopping center in underground passage increased for efficient space utilization in urban area. This study describes operation characteristics of all air type and hybrid type with local ventilation and fan coil unit fixed to ceiling. In order to compare energy saving, thermal environment and installation space, etc., integrated simulator with heat production and indoor distribution system is designed and constructed. Energy saving of the hybrid system is calculated as over 30% compared to conventional all air type. And also the results showed that humidity decreased about 6%, also indoor thermal distribution is improved as temperature variation of around $1^{\circ}C$.

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A Study on the Variation of the Transmission Capacity by External water Cooled System with Trough in Tunnel (전력구트라프내간접수냉방식에서의 송전용량 변화에 관한 연구)

  • 박만흥;조규식;김재근;서정윤
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.41 no.5
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    • pp.445-458
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    • 1992
  • As one of the forced cooling method of the underground power transmission system, external water cooled system with trough in tunnel was investigated. This study is performed on thermal analysis for a standard condition to determine the cable transmission current of the underground power transmission system about the cooling facility. A parametric study was performed for the inlet water temperatures, flow rates, the inlet air velocities, flow rates and the cooling spans. This study shows that the cable transmission current varies within the allowable limitation in compliance with the variation of inlet water temperatures and flow rates. It exhibits little variations for the most intervals in compliance with the variation of inlet air temperatures and flows. But, the cable transmission current fast reduces for a specified interval and consequently affects the underground transmission system. As a result, when the actual forced cooling system is designed, the design conditions of inlet air have to be considered as the most important parameters in determination of the cable transmission current.

System Effectiveness of AirDam for Natural Ventilation by U-CDS (U-CDS의 자연환기를 위한 AirDam시스템의 효과에 대한 연구)

  • Seungchul, Kim;Boohyun, Shin;Gidae, Oh
    • KEPCO Journal on Electric Power and Energy
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    • v.8 no.2
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    • pp.87-92
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    • 2022
  • Recently, there has been an increasing demand for electric equipment installed on the ground to be installed in an underground space. Accordingly, U-CDS (Underground-Compact Distribution Station) installed in the underground is supplied, and to improve its weak ventilation performance, an Airdam-type structure was applied and the effect was analyzed. As a result, the temperature around the transformer was reduced by up to 9.5 degrees, and the air flow increased by up to 1.17 m/s. Airdam structure can be supplied in the form of various sculptures because it is possible to design freely while maintaining its principle.

The Characteristics of Indoor Air Quality Variation in Underground Parking Lots of Apartments located in Northern Gyeonggi Province (경기도 북부지역 아파트의 지하주차장 실내공기질 변동 특성)

  • Park, Hyun-Ku;Jung, Yeon-Hoon;Kim, Byeong-Lok;Kim, Jin-gil;Shin, Hyung-Soon;Lee, Sang-Soo;Oh, Jo-Kyo
    • Journal of Environmental Health Sciences
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    • v.44 no.3
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    • pp.250-258
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    • 2018
  • Objectives: The study examined indoor air quality during daytime and commute times in underground parking lots in five apartments located in northern Gyeonggi province. Methods: This study examined the temporal characteristics of $PM_{10}$, $CO_2$, CO, HCHO and VOCs in the indoor air quality of the underground parking lots in five apartments. Results: $PM_{10}$ concentration in daytime were ranged from 37.4 to $69.9{\mu}g/m^3$ which complied with the indoor air quality maintenance standard ($200{\mu}g/m^3$) and Gyeonggi province ordinance standard ($180{\mu}g/m^3$). However $PM_{10}$ concentrations in commuting time were in range of $447.3{\sim}944.0{\mu}g/m^3$ that exceeded for both criteria. The $CO_2$, CO and HCHO concentrations complied with the standard. The VOCs indicated high tendency in the order of toluene, xylene, ethylbenzene and benzene. This tendency was more apparent in commuting time than daytime. Conclusion: All indoor parking lots of five apartments were equipped with ventilators. However the most apartment residents did not operate blowers to save electricity and the lack of interest for indoor air quality. In order to improve the indoor air quality of underground parking lots in apartment, operating ventilation system during commuting time is recommended.

Study on Designing and Installation Effect of Fresh Air Load Reduction by using Underground Double Floor Space-Experimental Result and Proposal of Numerical Model for Thermal Performance- (지열을 이용한 공조외기부하저감(空調外氣負荷低減)시스템의 설계 및 도입 효과에 관한 연구 -실측결과 및 열성능 예측을 위한 수치모델의 제안-)

  • Son, Won-Tug;Choi, Young-Sik
    • Journal of the Korean Society of Industry Convergence
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    • v.7 no.3
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    • pp.233-240
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    • 2004
  • This paper presents a feasibility study of a fresh air load reduction system by using an underground double floor space The system was introduced into a real building and was examined by the field measurement Judging from the measurements during three years(1999~2001), the state of the system operation was very stable through this period and it was clear that the system contributes to reduction of energy consumption for air-conditioning. Futhermore, a simulation model used the simple heat diffusion equation Was developed to simulate its thermal characteristics and performances The simulations resulted m air temperature in good agreement with the measurements. Also, from the result of numerical analysis, It is clear that the amount of heat supply by using this system is more than the amount of energy loss to the room above it. Therefore, it is concluded that this systems is very useful and the proposed numerical model can be used for the prediction of system thermal performance.

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The Study on the Prediction of Underground Temperature in Changwon District (창원지역의 지중온도 예측에 관한 연구)

  • Cho, Sung Woo;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.26 no.3
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    • pp.97-102
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    • 2014
  • For an analysis of the horizontal-type geothermal heat exchanger system, an understanding of the ground temperature distributions is required in order to predict system performance. Because it is difficult to decide on the underground temperature due to the adjustment of its temperature cycle, numerous calculations are required in order to decide on the temperature cycle. In this paper, Buggs formula is utilized to decide a phase shift for outdoor temperature and ground surface temperature, which are obtained from Korea Meteorological Administration. Overall, the underground temperature distribution in the Changwon region is predicted as $10.5^{\circ}C{\sim}20.3^{\circ}C$ at a depth of 3 m.