• Title/Summary/Keyword: $SF_6/CO_2$

Search Result 100, Processing Time 0.029 seconds

Separation and Recovery of F-gases (불화 온실 가스 저감 및 분리회수 기술의 연구개발 동향)

  • Nam, Seung-Eun;Park, Ahrumi;Park, You-In
    • Membrane Journal
    • /
    • v.23 no.3
    • /
    • pp.189-203
    • /
    • 2013
  • F-gases, gases containing fluorine such as perfluorocarbons (PFCs), sulfurhexafluoride ($SF_6$), nitrogen trifluoride ($NF_3$) are known to have green house effects. Although the net emission rates of gases containing fluorine are much lower than those of $CO_2$, their contribution to global warming cannot be ignored because of their extremely high global warming potential (GWP). F-gases mainly have been used for a variaty of applications in the semiconductor/LCD processes and in the electric power distribution industry of the national key industry. One of practical solutions of controlling the emission rates of F-gases is to reuse by separation and recovery of F-gases of low concentration from the gases mixtures with nitrogen or air. This work investigates some methods for F-gases recovery and separation around the membrane-based process.

Analysis on the Dielectric Characteristics of Dry-air (Dry-air의 절연 특성 분석)

  • Bang, Seungmin;Mo, Young Kyu;Lee, Onyou;Kim, Junil;Kang, Jong O;Lee, Hongseok;Nam, Seokho;Kang, Hyoungku
    • Proceedings of the KIEE Conference
    • /
    • 2015.07a
    • /
    • pp.1195-1196
    • /
    • 2015
  • 최근 급격한 산업사회의 발달로 인해 전력기기의 종류와 설치개수가 꾸준히 증가하고 있다. 수많은 고전압 전력기기의 운용으로 인해 발생되는 온실가스는 지구온난화와 같은 환경파괴를 유발시키는 등의 문제를 발생시키고 있다. 고전압 전력기기의 전기적 절연을 위해 주로 사용되는 SF6와 같은 기체 절연체는 온실가스를 유발시키며, 현재 여러 나라에서는 고전압 전력기기로부터 방출되는 CO2의 양을 최소화하기 위한 많은 연구가 진행되고 있다. 특히, 일본 교토에서 180여개의 국가가 온실가스 감축의 의무를 나누고자 교토의정서를 채택하였고, 온실가스를 유발하는 SF6를 대체할 수 있는 친환경 기체 절연체에 대한 연구가 활발히 진행 중이다. 그 중에서도 본 연구에서는 친환경 기체 절연체인 Dry-air의 절연파괴와 부분방전 개시전압 특성을 분석하였다. 다양한 구 전극의 크기와 전극 사이 간격 조건에서 AC 절연파괴 및 부부방전 개시전압에 대한 실험을 수행하였다. 또한, 유한요소해석을 통해 산출한 전계 이용률을 고려하여 절연파괴와 부분방전 개시전압에 대한 특성을 분석하였다. 실험결과, 구 전극의 크기와 전극 사이 간격이 증가할수록 절연파괴와 부분방전 개시전압의 크기가 커지는 것을 알 수 있으며, 부분방전이 먼저 개시되고 절연파괴로 이어는 경향을 확인할 수 있었다. 또한, 전계 이용률이 0.52 이상에서는 부분방전이 개시되지 않고 곧바로 절연파괴로 이어지는 것을 확인할 수 있었다.

  • PDF

업무용 건물의 전력소비특성을 고려한 수용률 기준

  • 오기봉;김세동;신효섭;김수길
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.18 no.3
    • /
    • pp.39-43
    • /
    • 2004
  • 국제적인 환경 규제 문제($CO_2$, SF$_{6}$(육불화황), PFC (과불화화합물) 등)가 새로운 무역장벽으로 등장하여 우리나라 주요 산업 부문에 미치는 영향이 점차 현실로 나타나고 있다. 이러한 환경 규제에 적절한 대처를 하기 위해 에너지 소비 증가와 이에 따르는 에너지 소비 패턴 및 인식에 대한 새로운 접근 방법이 요구되고 있다. 그동안 전력기기의 고효율화, 에너지 효율 향상과 수요관리 강화, 미활용 에너지원의 이용률 제고, 집단에너지 보급 확대 등 하드웨어적인 기술개발에 중점을 두고 추진되었으나, 앞으로는 전원설비, 전력전송 설비, 부하설비 등의 최적 설계기술을 통한 에너지절약 기술개발과 같은 소프트웨어적인 기술 개발이 요청되고 있다. (중략)

  • PDF

Effect of Ca Addtion on Microstructure and Mechanical Properties of Mg-11Li-3Zn-1Sn-0.4Mn Based Alloys (Mg-11Li-3Zn-1Sn-0.4Mn 마그네슘 합금의 Ca 첨가에 따른 미세조직 및 기계적 특성평가)

  • Kim, Jung-Han;Kim, Yong-Ho;Yoo, Hyo-Sang;Son, Hyeon-Taek;Lee, Seong-Hee
    • Korean Journal of Materials Research
    • /
    • v.25 no.6
    • /
    • pp.269-273
    • /
    • 2015
  • The effect of adding Ca on the microstructural and mechanical properties of as-cast Mg-11Li-3Zn-1Sn(wt%) alloys were investigated. Mg-11Li-3Zn-1Sn-0.4Mn with different Ca additions (0.4, 0.8, 1.2 wt%) were cast under an $SF_6$ and $Co_2$ atmosphere at $720^{\circ}C$. The cast billets were homogenized at $400^{\circ}C$ for 12h and extruded at $200^{\circ}C$. The microstructural and mechanical properties were analyzed by OM, XRD, SEM, and tensile tests. The addition of Ca to the Mg-11Li-3Zn-1Sn-0.4Mn alloy resulted in the formation of $Ca_2Mg_6Zn_3$, MgSnCa intermetallic compound. By increasing Ca addition, the volume fraction and size of $Ca_2Mg_6Zn_3$ with needle shape were increased. This $Ca_2Mg_6Zn_3$ intermetallic compound was elongated to the extrusion direction and refined to fine particles due to severe deformation during hot extrusion. The elongation of the 0.8 wt% Ca containing alloy improved remarkably without reduction strength due to the formation of fine grain and $Ca_2Mg_6Zn_3$ intermetallic compounds by Ca addition. It is probable that fine and homogeneous $Ca_2Mg_6Zn_3$ intermetallic compounds played a significant role in the increase of mechanical properties.

$High-J_c\;NdBa_2Cu_3O_{7-{\delta}}$ thin films on $SrTiO_3$(100) substrates prepared by the PLD process

  • Wee, Sung-Hun;Moon, Seung-Hyun;Yoo, Sang-Im
    • Progress in Superconductivity and Cryogenics
    • /
    • v.11 no.2
    • /
    • pp.1-6
    • /
    • 2009
  • We report a successful fabrication of $high-J_c\;NdBa_2Cu_3O_{7-{\delta}}$ (NdBCO) films on $SrTiO_3$(STO) (100) substrates by pulsed laser deposition (PLD) in a relatively wide processing window. Under various oxygen pressures controlled by either 1%$O_2$/Ar mixture gas or pure $O_2$ gas, strongly c-axis oriented NdBCO films were grown at the substrate temperature $(T_s)\;of\;800^{\circ}C$ in 800 mTorr with 1%$O_2$/Ar gas and also in 400 and 800 mTorr with pure $O_2$ gas. These samples exhibited $T_c$ values over 90K and $J_c$ values of $2.8-3.5MA/cm^2$ at 77K in self-field (77K, sf). On the other hand, $J_c$ values over $1A/cm^2$ were obtained at the temperature regions of $700-830^{\circ}C$ in 800 mTorr with 1%$O_2$/Ar gas at those of $750-830^{\circ}C$ in 800 mTorr with pure $O_2$ gas. Unlike previous reports, resent results support that the PLD processing window for high-Jc NdBCO films is not narrow.

The effects of aluminium contents on the mechanical properties of magnesium-aluminium alloy (Mg-Al계 합금의 기계적 성질에 미치는 Al의 영향)

  • Maeng, W.Y.;Bac, J.H.;Oh, I.S.;Nam, T.W.
    • Journal of the Korean Society for Heat Treatment
    • /
    • v.7 no.2
    • /
    • pp.139-146
    • /
    • 1994
  • In the molten state, magnesium alloys vigousey react with oxygen in the air, is protected from oxidation and burning by the addition of $SF_6$ to $CO_2$ atmosphere over the melt. The mechanical properties and metallographic examinatin have made of Mg-Al alloys containing 3, 6, 9% in the solution treated state and precipitated state, comparing mechanical properties obtained during unidirectional solidification with me chanical properties obtained during conventional casting. For a given solution treatment, a higher aluminum contents produce more or less fine grains in conventional casting. For a given artifical aging treatment, a higher aluminum contents produces much precitates at the grain boundary as well as within the grain in unidirectional solidification. As a result of this experiment, for a given heat treatment, the higher is aluminum contents the higher is the ultimate tensile strength, yield strength, hardness while the lower the elongation. Also the mechanical properties of unidirectional solidification is larger than that of conventional casting.

  • PDF

Acupuncture and Herbal Medicine Improved the Quality of life of Obese Women (한방치료를 받은 여성 비만환자의 삶의 질 연구)

  • Jung, Soon-Kwan;Yeom, Seung-Ryong;Kwon, Young-Dal
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.21 no.4
    • /
    • pp.1034-1038
    • /
    • 2007
  • To examine the difference of health-related quality of life (QoL) of obese patients between before and after treatment of Korean traditional medicine. This study was assessed in 18 obese-women (age 29.72${\pm}$7.38) treated by acupuncture and herbal medicine using SF-36 quality of life questionnaire between January and July 2006, a 36 item instrument yielding 8 dimensions (Social functioning, Role limitation-Physical, Role limitation-Emotion, Mental health, Vitality, Bodily pain, and General health) and a total score. Their weight was measured by Inbody 3.0 (Biospace co. Korea). QoL and body composition was assessed twice at baseline (B) and 4 weeks after treatment. Auricular acupuncture and electrical needle stimulation to abdomen, thigh, and arm fat was used twice a week and complex herb formula was prescribed according to their constitution and symptoms for 4 weeks. Herb medication was taken 2 times a day. Respective variables were analyzed with Wilcoxon signed ranks test and the level set for statistical significance was p <0.05. The mean of the body weight (P=0.000;B64,68${\pm}$6.86, 4 WKs 60.47${\pm}$5.69), fat percentage (P=0.000;B33.14${\pm}$4.86, 4 WKs 30.16${\pm}$5.34), body mass index (P=0.000;B25.18${\pm}$2.44, 4 WKs 23.46${\pm}$2.09) and fat weight (P=0.000;B21.66${\pm}$5.06, 4 WKs 18.41${\pm}$4.57) of some obese patients decreased significantly between before and after treatment for 4 weeks. Physical functioning (P=0.48;B27.06${\pm}$3.17, 4 WKs 28.00${\pm}$1.71), Mental health (P=0.01 ;B18.83${\pm}$5.25, 4 WKs 22.00${\pm}$3.73), Vitality (P=0.028;B13.89${\pm}$3.03, 4 WKs 15.44${\pm}$2.53), Bodily pain (P=.0014;B8.84${\pm}$1.75, 4 WKs 10.15${\pm}$1.78), and the total scores (P=0.001;B104.99${\pm}$12.60, 4 WKs 114.58${\pm}$11.11) of SF-36 were increased significantly after treatments. These data show some differences in QoL and BMI between before and after treatment on obesity and suggest that the treatment with acupuncture and herbal medicine have a positive impact on several domains of QoL of some obese patients. Further randomized clinical trials (RCTs) including follow-up are needed to examine whether acupuncture and herb medicine have a positive effect on QoL of treatment group compared with control group.

Analysis of Carbon Emissions According to Combustion of Surface Fuels (지표연료의 연소에 따른 탄소배출량 분석)

  • Park, Young Ju;Lee, Hae Pyeong;Kim, Min Jung;Kim, Hae Rim
    • 한국방재학회:학술대회논문집
    • /
    • 2011.02a
    • /
    • pp.192-192
    • /
    • 2011
  • 교토의정서에서 지구온난화의 원인이 되는 온실가스로 $CO_2$, $CH_4$, $N_2O$, HFCs, PFCs, $SF_6$를 규제하고 있다. 규제하는 6대 온실가스 가운데 $CO_2$가 가장 대표적이며, 우리나라의 연료연소에 의한 $CO_2$ 배출량은 세계 10위로 기후변화 진행속도는 세계 평균속도보다 빠르게 진행되고 있다. 이러한 기후변화에 대응하기 위하여는 온실가스 배출로 인한 DB구축 연구가 선행되어야 하며, 산림부분에 있어서는 연료의 열적특성 구명 연구가 극도로 미진한 국내현실에서 기초 data 확보를 위한 연구가 시급한 실정이다. 따라서, 본 연구에서는 산불발생 시 온실가스 배출량의 DB를 구축하기 위하여 산불발생 시 배출되는 탄소배출량을 예측하고자 산림 가연물의 연소실험을 수행 하였다. 연소실험은 산림 연료 가운데 지표연료 10가지(소나무낙엽, 굴참나무낙엽, 소나무솔방울, 밤나무밤송이껍질, 방아풀, 주름조개풀, 칡, 엉겅퀴, 김의털, 고비)를 대상으로 콘칼로리미터 장비를 이용하여 이산화탄소와 일산화탄소 배출량을 분석하였다. 탄소배출량 실험에 앞서 지표연료들의 함수율을 측정한 결과, 10가지 지표연료 가운데 고사한 연료(낙엽, 솔방울, 밤송이)는 9~24% 정도, 생연료인 초본류 6가지는 181~484% 정도인 것으로 나타났으며, 솔방울과 밤송이의 경우 9~10%로 가장 수분을 적게 함유하고 있음을 알 수 있었다. 탄소배출량 분석 결과, 50g 중량에 대한 10가지 지표연료들의 이산화탄소 총배출량은 28~98g 정도, 일산화탄소 총배출량은 0.76~4.08g 정도 배출하는 것으로 나타나 연료별 차이를 보였으며, 특히, 고사한 연료와 생연료의 탄소배출량 차이는 큰 것으로 나타났다. 일산화탄소 총배출량은 고사한 연료(소나무낙엽, 굴참나무 낙엽, 소나무 솔방울, 밤나무 밤송이)는 3.24~4.08g 정도, 생연료 초본류 6가지(방아풀, 주름조개풀, 칡, 엉겅퀴, 김의털, 고비)는 0.76~2.73g 정도 배출하는 것으로 나타났다. 이산화탄소 총배출량은 함수율이 현저히 낮은 4가지 연료(소나무 낙엽, 굴참나무 낙엽, 소나무 솔방울, 밤나무 밤송이 껍질)들은 52~98g 정도, 함수율이 높은 6가지 초본류는 28~48g 정도의 이산화탄소를 배출하는 것으로 나타났다. 따라서, 고사한 연료인 소나무 낙엽, 굴참나무 낙엽, 소나무 솔방울, 밤나무 밤송이는 초본류 보다 상대적으로 이산화탄소와 일산화탄소 배출량이 많은 것으로 나타났으며, 특히, 소나무 솔방울은 가장 많은 이산화탄소와 일산화탄소를 배출하는 것으로 나타났다. 상대적으로 방아풀과 주름조개풀은 각각 28g과 35g으로 이산화탄소 배출량이 작은 것으로 나타났다. 따라서, 산불발생 시, 소나무의 솔방울은 10가지 지표연료 가운데 상대적으로 많은 이산화탄소와 일산화탄소를 배출할 것으로 사료된다.

  • PDF

High Temperature Creep Strength of Mg-Nd-Zr-Zn Alloy in Sand Castings (사형주조한 Mg-Nd-Zr-Zn합금의 고온 크리이프강도)

  • Kang, Dae-Min;Park, Kyung-Do;Park, Ji-Hee
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.10 no.6
    • /
    • pp.83-88
    • /
    • 2011
  • Magnesium alloys have been focussed for the applications for lightweight of vehicle and electronics due to their high strength, low specific density and good damping capacity. This paper deals with the creep strength of Mg-Nd-Zr-Zn alloy. For the alloy, pure magnesium(99.9%) was melt with atmosphere of $0.3%SF_6$ and $25%CO_2$. After melting, 0.3% of zinc was inserted to stir for 10min at elevated temperature of $770^{\circ}C$. Master alloys of Mg-15%Nd and Mg-15%Zr were stirred in furnace. The creep tests were performed to obtain creep rate and rupture in the temperature range of 200 to $220^{\circ}C$ and 280 to $310^{\circ}C$ at an applied stress of 156 to 172MPa and 78 to 94MPa, respectively. The deformation mechanism was predicted dislocation climb from measured apparent activation energy and stress exponent. Also the increaser the temperature and stress the lower the stress exponent and activation energy. Finally, LMP parameter gives good information for the predicted creep rupture life.

Estimation of Domestic Greenhouse Gas Emission of Refrigeration and Air Conditioning Sector adapting 2006 IPCC GL Tier 2b Method (국내 냉동 및 냉방부문 온실가스 배출량 산정 - 2006 IPCC GL Tier 2b 적용 -)

  • Shin, Myung-Hwan;Lyu, Young-Sook;Seo, Kyoung-Ae;Lee, Sue-Been;Lim, Cheolsoo;Lee, Sukjo
    • Journal of Climate Change Research
    • /
    • v.3 no.2
    • /
    • pp.117-128
    • /
    • 2012
  • The Government of South Korea has continued its effort to fixate virtuous circle of economic growth and climate change response to cope with international demands and pressure to commitment for greenhouse gas reduction effectively. Nationally, Korean Government has established "Enforcement of the Framework Act on Low carbon, Green Growth"(2010. 4. 13) to implement national mid-term GHG mitigation goal(30% reduction by 2020 compare to BAU), which established the foundation for phased GHG mitigation by setting up the sectoral and industrial goal, adopting GHG and Energy Target Management System. Also, follow-up measures are taken such as planning and control of mid-term and short-term mitigation target by detailed analysis of potential mitigation of sector and industry, building up the infrastructure for periodic and systematic analysis of target management. Likewise, it is required to establish more accurate, reliable and detailed sectoral GHG inventory for successfully establishment and implement the frame act. In comparison to the $CO_2$ emission, Especially fluorinated greenhouse gases (HFCs, PFCs, $SF_6$) are lacking research to build the greenhouse gas inventories to identify emissions sources and collection of the applicable collection activities data. In this study, with the refrigeration and air conditioning sector being used to fluorine refrigerant(HFCs) as the center, greenhouse gas emission estimation methodology for evaluating the feasibility of using this methodology look over and mobile air conditioning, fixed air conditioning, household refrigeration equipment, commercial refrigeration equipment for the greenhouse gas emissions were calculated. First look at in terms of methodology, refrigeration and air conditioning sector GHG emissions in developing country-specific emission factors and activity data of the industrial sector the construction of the DB is not enough, it's 2006 IPCC Guidelines Tier 2a (emission factor approach) rather than the Tier 2b (mass balance approach) deems appropriate, and each detail by process, sectoral activity data more accurate, if DB is built Tier 2a (emission factor approach) can be applied will also be judged. Refrigeration and air conditioning sector in 2009 due to the use of refrigerant greenhouse gas emissions ($CO_2eq.$) assessment results, portable air conditioner 1,974,646 ton to year, fixed-mount air conditioner 1,011,754 ton to year, household refrigeration unit 4,396 ton to year, commercial refrigeration equipment 1,263 ton to year was estimated to total 2,992,037 tons.