• Title/Summary/Keyword: Gas Mixture

Search Result 2,019, Processing Time 0.027 seconds

A study of the Insulation Characteristic in $SF_6-N_2$ Mixture Gases ($SF_6-N_2$ 혼합기체의 절연특성에 관한 연구)

  • Ha, Sung-Chul;Song, Byoung-Doo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2001.11b
    • /
    • pp.613-616
    • /
    • 2001
  • This SF6 gas is widely used in industrial of insulation field. In this paper, N2 is mixed to improve pure SF6 gas characteristics. Electron transport coefficients in SF6-N2 mixture gases are simulated in range of E/N values from 70 to 400 [Td] at 300K and 1 Torr by using Boltzmann equation method. The results of this method, which are like electron drift velocity, ionization coefficient, attachment coefficient, effective ionization coefficient, and critical EIN, can be important data to present characteristic of gas for insulation. Specially critical E/N is a data to evaluate insulation strength of a gas and is presented in this paper for various mixture ratios of SF6-N2 mixture gases.?⨀␍?܀㘱〮㜳㬓M敤楣楮攠慮搠桥污瑨

  • PDF

Surface Discharge Characteristics in Different Media (이종절연재의 연면절연특성)

  • Shin, Sung-Ha
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.15 no.2
    • /
    • pp.49-54
    • /
    • 2012
  • With the improvement of industrial society, the high quality electrical energy, simplification of operation and maintenance, ensuring reliability and safety are being required. This paper reviews a basic data of the surface discharge characteristics for teflon resin in not only pure $N_2$, $N_2:O_2$ mixture gas and Dry-Air as being focused on environmentally friendly insulating Gas also $SF_6$. Used electrodes are Knife to Knife. With the changing distance of electrodes and pressure, we can find it, surface discharge voltages and surface dielectric strengths, respectively. Surface discharge Voltages of $N_2:O_2=80:20$ mixture gas are more higher than the $N_2:O_2$ Mixture gases.

A study of the Insulation Characteristic in $SF_{6}$-$N_2$ Mixture Gases ($SF_{6}$-$N_2$ 혼합기체의 절연특성에 관한 연구)

  • 하성철;송병두
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2001.11a
    • /
    • pp.613-616
    • /
    • 2001
  • This $SF_{6}$ gas is widely used in industrial of insulation field. In this paper, $N_2$ is mixed to improve pure $SF_{6}$ gas characteristics. Electron transport coefficients in $SF_{6}$-$N_2$ mixture gases are simulated in range of E/N values from 70 to 400 [Td] at 300K and 1 Torr by using Boltzmann equation method. The results of this method, which are like electron drift velocity, ionization coefficient, attachment coefficient, effective ionization coefficient, and critical E/N, can be important data to present characteristic of gas for insulation. Specially critical E/N is a data to evaluate insulation strength of a gas and is presented in this paper for various mixture ratios of $SF_{6}$-$N_2$ mixture gases.

  • PDF

Thermal Recovery Characteristics of a CO2 Mixture Gas Circuit Breaker

  • Oh, Yeon-Ho;Song, Ki-Dong;Lee, Hae-June;Hahn, Sung-Chin
    • Journal of Electrical Engineering and Technology
    • /
    • v.11 no.4
    • /
    • pp.969-973
    • /
    • 2016
  • Interruption tests were conducted using the same circuit breaker for an initial pressure of SF6 0.5 MPa (gauge pressure) and CO2 mixture 1.0 MPa, 0.8 MPa, and 0.6 MPa. The pressure-rises in the compression and thermal expansion chambers were measured for verifying the computational results using a simplified synthetic test facility. Further, the possibility of the CO2 mixture substituting SF6 gas was confirmed. Moreover, in view of the thermal recovery capability, it has also been confirmed that the pressure of the CO2 mixture can be reduced almost to the same value as that of the SF6 gas by optimizing the design parameters of the interrupter.

Prediction of Transport Properties for Transportation of Captured CO2. 1. Viscosity (수송조건 내 포집 이산화탄소의 전달물성 예측. 1.점성)

  • Lee, Won Jun;Yun, Rin
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.29 no.4
    • /
    • pp.195-201
    • /
    • 2017
  • In this study, the viscosity of a $CO_2-gas$ mixture was investigated for the transportation of the captured $CO_2-gas$ in pipelines and for the designing of a thermal system, both of which involve the utilization of the $CO_2-gas$ mixture. The viscosities of the $CO_2-gas$ mixture, $CO_2+CH_4$, $CO_2+H_2S$, and $CO_2+N_2$ were predicted using three different models as follows : Chung, TRAPP, and REFPROP. The predictability values of the models were validated by comparing the estimated results with the experiment data for the $CO_2+CH_4$ and $CO_2+N_2$ under high-density conditions. The Chung model showed 2.41%, which is the lowest mean deviation of the prediction among the model. Based on the Chung model, the mixture mole fractions were changed from 0.9, 0.95, and 0.97, the mixture pressure was ranged from 80 bar to 120 bar by 10 bar, and the mixture temperature was varied from 310 K to 400 K by 10 K to observe the effects of the parameters on the mixture viscosity. Considering the high mole fraction of the $CO_2$ in the mixture, a significant variation of the mixture viscosity was observed close to the pseudo-critical temperature, and the viscosity for the $CO_2+H_2S$ mixture shows the highest values compared with those of the $CO_2+CH_4$ and $CO_2+N_2$.

Analysis of Insulating Characteristics of Cl2-He Mixture Gases in Gas Discharges

  • Tuan, Do Anh
    • Journal of Electrical Engineering and Technology
    • /
    • v.10 no.4
    • /
    • pp.1734-1737
    • /
    • 2015
  • Insulating characteristics of Cl2-He mixture gases in gas discharges were analysed to evaluate ability of these gases for using in medium voltage and many industries. These are electron transport coefficients, which are the electron drift velocity, density-normalized longitudinal diffusion coefficient, and density-normalized effective ionization coefficient, in Cl2-He mixtures. A two-term approximation of the Boltzmann equation was used to calculate the electron transport coefficients for the first time over a wide range of E/N (ratio of the electric field E to the neutral number density N). The limiting field strength values of E/N, (E/N)lim, for these binary gas mixtures were also derived and compared with those of the pure SF6 gas.

Improvements of the luminous efficiency of mercury-free fluorescent lamps via structural and complex gas mixture changes

  • Oh, Byung-Joo;Jung, Jae-Chul;Seo, In-Woo;Kim, Hyuk;Whang, Ki-Woong
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2008.10a
    • /
    • pp.809-812
    • /
    • 2008
  • Structural parameter variation effects (changing the coplanar gap under different discharge dimensions) and use of complex gas mixtures (He, Ne, Ar and Xe) in mercury-free fluorescent lamps are studied in this paper. Pure Neon gas is the best buffer gas for obtaining high luminous efficiency in mercury-free fluorescent lamps. It is shown that with a shorter coplanar gap (30mm), a high luminous efficiency can be obtained at low operating voltage, as well as high luminance uniformity and stable discharge with a Ne-Xe 20% gas mixture.

  • PDF

Determination of the mole fractions of ethylene oxide and freons in medical liquefied gas mixture by GC/AED (GC/AED를 이용한 의료용 액화혼합가스 중 산화에틸렌 및 프레온 가스류의 몰분율 측정)

  • Kim, Hyunjoo;Kim, Dalho;Lim, Arang;Lee, Taeck-Hong;Kim, Jin Seog
    • Analytical Science and Technology
    • /
    • v.25 no.6
    • /
    • pp.382-387
    • /
    • 2012
  • Ethylene oxide ($C_2H_4O$, EtO) is used as a raw material for the production of ethylene glycol and other industrially important material such as ethanolamines and also used as a disinfecting agent. It is applied for gas-phase sterilization of thermally sensitive medical equipment, and for processing of storage facilities as a mixture with fluorinated hydrocarbon. In this perspective, accurate determination of the mole fractions of components in the liquefied gas mixture is required for the quality control and safety of production and use. Each component of the liquefied gas mixture has different chemical and physical properties such as vapor pressure and boiling point. Therefore, we can suppose that analytical results can be different according to the introduction method for the gas phase of upper layer, or for the liquid phase of lower layer in gas cylinder. In this study, we designed a new on-line sample injection device for the liquefied gas mixture in liquid or gas state, and applied to the analysis of liquefied gas mixture of ethylene oxide and fluorinated hydrocarbons by GC/AED (gas chromatograph-atomic emission detector). We studied performance of AED, and effect of sample introduction and selected wavelength to the accuracy and repeatability of analytical results.

A Study on Syngas Co-combustion Characteristics in a Heavy Oil Combustion System with Multi Burners (멀티 버너 중유 연소로에서의 합성 가스 혼합 연소 특성 연구)

  • Yang, Dong-Jin;Choi, Shin-Young;Yang, Won
    • Journal of the Korean Society of Combustion
    • /
    • v.15 no.1
    • /
    • pp.43-49
    • /
    • 2010
  • Co-combustion of syngas in an existing boiler can be one of the options for replacing conventional fossil fuel with alternative fuels such as waste and biomass. This study is aimed to investigate effects of syngas cocombustion on combustion characteristics and boiler efficiency. An experimental study was performed for a pilot-scale furnace with 4 oil burners. Tests were conducted with mixture-gas as a co-combustion fuel and heavy oil as a main fuel. The mixture-gas was composed of 15% CO, 7% $H_2$, 3% $CH_4$ and 75% $N_2$ for simulating syngas from air-blown gasification. And LHV of the mixture-gas was 890 kcal/$Nm^3$. Temperature distribution in the furnace and flue gas composition were measured for various heat replacement ratio by the mixture gas. Heat loss through the wall was also carried out through heat & mass balance calculation, in order to obtain informations related to boiler efficiency. Experimental results show that similar temperature distribution and flue gas composition can be obtained for the range of 0~20% heat replacement by syngas. NOx concentration is slightly decreased for higher heat replacement by the syngas because fuel NOx is decreased in the case. Meanwhile, heat loss is a bit decreased for higher heat replacement by the syngas, which implies that boiler efficiency can be a bit decreased when syngas co-combustion is applied to a boiler.

Influence of gas flow on structural and optical properties of ZnO submicron particles grown on Au nano thin films by vapor phase transport (가스 유입량이 기상이동법으로 금 나노박막위에 성장된 산화아연 입자에 미치는 영향)

  • Kim, So-A-Ram;Nam, Gi-Ung;Kim, Min-Su;Park, Hyeong-Gil;Yun, Hyeon-Sik;Im, Jae-Yeong
    • Proceedings of the Korean Institute of Surface Engineering Conference
    • /
    • 2012.05a
    • /
    • pp.211-212
    • /
    • 2012
  • ZnO submicron particles were grown on Au-catalyzed Si substrate by a vapor phase transport (VPT) growth process under different mixture gas ratio at growth temperature of $900^{\circ}C$. The structural and optical properties of the ZnO submicron particles were investigated by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and photoluminescence (PL). The ZnO submicron particles could be clustered with the $O_2/Ar$ mixture gas ratio(%) higher than 10%, and it was mainly determined by the gas ambient. Particularly, when the $O_2/Ar$ mixture gas ratio was 30%, it was observed the ZnO submicron particles with diameters in the range of 125 to 500 nm and the narrowest full width at half maximum (FWHM) of XRD and PL spectra with $0.121^{\circ}$ and 92 meV, respectively. It was found that the structural and optical properties of the ZnO submicron particles were improved with increasing the $O_2/Ar$ mixture gas ratio through the XRD and PL spectra.

  • PDF