• Title/Summary/Keyword: City Gas

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Validity Review on Classification of Explosion Hazardous Area using Hypothetic Volume (가상체적을 이용한 폭발위험장소 구분의 타당성 검토)

  • Yim, Ji-Pyo;Chung, Chang-Bock
    • Journal of the Korean Society of Safety
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    • v.29 no.6
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    • pp.68-75
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    • 2014
  • It is very important to classify explosion hazardous area (EHA) suitably and to use proper explosion-proof electric installations for facilities using flammable gases and liquids. In the past, various examples in the Notification of Ministry of Employment and Labor were referred to in classifying EHA. But, at present, many companies use the hypothetical volume in Korean Standards (KS). This study reviews the validity of EHA classification based on the hypothetical volume by comparing the calculated radii of EHA with those obtained by a consequence analysis program called PHAST and a mathematical approach in British Standards (BS). The radii of EHA by the hypothetical volume were found to be slightly larger than those by the other two methods. This was attributed to rather conservative uses of a safety factor(k) and a correction factor(f) for availability of ventilation in calculating the hypothetical volume. Since the differences are not so conspicuous, however, it is concluded that the hypothetical volume in KS is a valid means for the classification of EHA. This study also presents a table of the radii of EHA for easy reference by small-scale companies using city gas, C3-LPG and flammable liquid(toluene), respectively. The table consists of 25 leakage scenarios corresponding to combinations of 5 pipe(nozzle) sizes and 5 operating conditions for each flammable gas and liquid.

Radon Concentration at N-Kindergarten in G-City (G광역시 N유치원의 라돈 농도)

  • Park, Yun;Kim, Wonjun
    • Journal of the Korean Society of Radiology
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    • v.9 no.6
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    • pp.421-424
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    • 2015
  • In this study, To subject the constructed at N-kindergarten in G-city, the position is closed window and opened window was measured using a measuring instrument for radon. The measured results indicate that the measurement was carried out in concentrations of radon gas measured at N-kindergarten is low than United States in the radon concentration in air public 4pCi called radon gas baseline maximum allowable concentrations. As a result, radon exposure is not a problem, but when the accumulation radon gas in the lungs, get damaged same lung cancer. Be defensive of kindergarten windows open for ventilation and dust removal be possible to reduce the exposure.

A STUDY ON THE EVALUTION METHOD OF THE GAS DISTRIBUTION COST IN KOREA (국내(國內) 천연(天然)가스 유통비용평가방법(流通費用評價方法)에 관한 연구(硏究))

  • Kim, Tae-Yu;Lee, Se-Jun;Min, Cheol-Gu
    • Environmental and Resource Economics Review
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    • v.1 no.1
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    • pp.1-25
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    • 1991
  • The domestic liquefied natural gas project has been carried out as a national energy scheme since the late 1980's in Korea. The natural-gas supply for civilian demand is limited to the Kyung-In area. In addition, seven major city gas corporations which now participate in the project occupy the monopolistic service area. In this study, objective cost evaluation criteria for gas distribution and an improved proposal in the evaluation method are suggested. They will go forward in solving the problems to promote demand and prevent excess profit or deficit according to the physical characteristics of the monopolistic service area.

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NOx Sensing Characteristics of the $WO_{3}$-Based Thin-Film Gas Sensors (박막형 $WO_{3}$계 가스센서의 NOx 감도 특성)

  • Yoo, Kwang-Soo
    • Journal of Sensor Science and Technology
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    • v.5 no.5
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    • pp.39-46
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    • 1996
  • The Pd or Pt-doped $WO_{3}$ thin-film NOx sensor was fabricated. The $WO_{3}$-based thin films as a gas-sensing layer were deposited at ambient temperature in a high-vacuum resistance heated evaporator and annealed at $500^{\circ}C$. The gas sensitivity ($R_{gas}/R_{air}$) to 5 ppm $NO_{2}$ measured at the operating temperature of $300^{\circ}C$ was 50 (highest sensitivity) for the 0.5 wt.% $Pt-WO_{3}$ sensor.

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A Study on the Diffusion Behavior of Leak Gas from Underground Gas Pipeline (지하매설 가스배관의 가스 누출시 지하 확산거동에 관한 연구)

  • Choi S.C.;Jo Y.D.;Kim K.S.
    • Journal of the Korean Institute of Gas
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    • v.3 no.2 s.7
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    • pp.43-52
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    • 1999
  • An experimental chamber was fabricated to observe the gas diffusion behavior of leak gas from underground city-gas pipeline. It was made of acryl so that feeding of gas and the measuring points of the gas could be varied in each experiment. The MOS sensors were used to measure the concentrations of leak gas. The soil media such as the Jumunjin standard sand and the granite weathered soil were used to measure the gas diffusion and the change of leak gas concentrations was measured with time for various gas flow rate. As the distance between the leak point of gas and the measuring point of MOS sensor decreases, or the leak rate increases, the detection time of gas at a measuring points decreases and the gas concentration increases quickly and the concentration of the gas at steady state also increases. As the density of granite weathered soil is higher than that of Jumunjin standard sand for compaction, the detection time of leak gas in the granite weathered soil was longer than that in the Jumunjin standard soil. The leak gas concentrations in the granite weathered soil were lower than those in the Jumunjin standard sand at the beginning of gas leaking from a pipe, but inverse phenomenon was occured at steady state.

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A Study on Reduction of Air Conditioning Energy Consumption by Surface Albedo Variation Using Meteorological Model (기상모델을 이용한 지표면 반사능에 따른 냉방에너지 소비 저감 연구)

  • AN, Jae-Ho
    • Journal of the Korean Solar Energy Society
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    • v.30 no.3
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    • pp.16-24
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    • 2010
  • Recently environmental regulations like the Kyoto Protocol, adopted in 1997, required the 5.2% reduction of the greenhouse gas emission in 1990. And 13th General Assembly in 2007, held in Bali of India, have agreed to duty reduction even in developing countries in 2013. Korean government needs the researches on climate change and the strategic programs for greenhouse gas reduction. In this paper Colorado State University Mesoscale Model(CSU-MM) was applied to simulate the relationship between surface albedo and air temperature. Meteorological model simulation in region of Ansan-City, Shiheung-City showed that mean air temperature became lower with the increase of albedo value. Simulated air temperature became lower $-0.16^{\circ}C$ and $-0.66^{\circ}C$ by 5% and 20% increase of albedo values respectively. And cooling energy saving amount in air conditioning process was calculated according to lowered air temperature. The reduction of air temperature resulted the reduction of air conditioning energy in personal house and commercial buildings. The increase of albedo from 5% to 20% resulted the reduction of air conditioning energy from 44,493 MWh/yr to 183,796 MWh/yr. Additionally the reduction of greenhouse gas emission through the energy saving was calculated after IPCC guideline. In terms of greenhouse gas emission $CO_2$ was reduced form -30,414 ton-$CO_2$/yr to -125,638 ton-$CO_2$/yr according to the reduction of electric energy.

Analysis of the Relationships among Energy, Economic Growth and Greenhouse Gas Emissions Using Metropolitan City/Province Level Data (광역시·도별 자료를 이용한 에너지, 경제성장, 온실가스 배출 간의 관계 분석)

  • Lee, Jaeseok;Lee, Keun-Dae;Yu, Bok-Keun
    • Environmental and Resource Economics Review
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    • v.30 no.3
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    • pp.503-533
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    • 2021
  • This paper analyzes the relationships among the energy consumption, renewable energy production, real gross regional domestic product(GRDP), and greenhouse gas(GHG) emissions. It uses the metropolitan city and province level data for Korea from 2010 to 2018, employing a panal vector autoregressive(VAR) model. We find that an increase in energy consumption has a limited impact on boosting renewable energy production or gross regional domestic product, while it leads to an increase in greenhouse gas emissions. A rise in renewable energy production can increase gross regional domestic product, but it has no meaningful effects on energy consumption and the reduction of green house gas emissions. Our finding indicates that it is crucial to expand the supply of renewable energy as well as to decrease energy consumption in order to achieve the goal of reducing greenhouse gas emissions and reaching economic growth.