• 제목/요약/키워드: separator.

검색결과 743건 처리시간 0.025초

Superconducting magnet system of in-flight separator for a heavy ion accelerator planned in Korea

  • Kim, J.W.;Kim, D.G.;Jo, H.C.;Choi, Y.S.;Kim, S.H.;Sim, K.D.;Sohn, M.H.
    • 한국초전도ㆍ저온공학회논문지
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    • 제17권1호
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    • pp.28-31
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    • 2015
  • An in-flight fragment separator, which aims to produce and study rare isotopes, consists of superferric quadrupole triplets and $30^{\circ}$ dipole magnets to focus and bend the beams for achromatic focusing and momentum dispersion, respectively. The separator is divided into pre and main stages, and we plan to use superconducting magnets employing high-Tc superconductor (HTS) coils in the pre-separator area, where radiation heating is high. The HTS coils will be cooled by cold He gas in 20-50 K, and in the other area, superferric magnets using low-temperature superconductor (LTS) will be used at 4 K. A few LTS coils were wound and successfully tested in a LHe dewar, and the design of cryostat has been optimized. Development of the HTS coils is ongoing in collaboration with a group at KERI. An HTS coil of racetrack shape was wound and tested in a $LN_2$ bath and in a dewar with cryocooler. No degradation on critical current due to coil winding was found.

고온 고분자전해질 연료전지 박판형 분리판의 유로 설계 및 스택 성능 평가 (Flow Field Design and Stack Performance Evaluation of the Thin Plate Separator for High Temperature Polymer Electrolyte Membrane Fuel Cell)

  • 김지홍;김민진;김진수
    • 한국수소및신에너지학회논문집
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    • 제29권5호
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    • pp.442-449
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    • 2018
  • Research on High temperature polymer electrolyte fuel cell (HT-PEMFC) has actively been conducted all over the world. Since the HT-PEMFC can be operated at a high temperature of $120-180^{\circ}C$ using phosphoric acid-doped polybenzimidazole (PBI) electrolyte membrane, it has considerable advantages over conventional PEMFC in terms of operating conditions and system efficiency. However, If the thermal distribution is not uniform in the stack unit, degradation due to local reaction and deterioration of lifetime are difficult to prevent. The thin plate separator reduces the volume of the fuel cell stack and improves heat transfer, consequently, enhancing the cooling effect. In this paper, a large area flow field of thin plate separator for HT-PEMFC is designed and sub-stack is fabricated. We have studied stack performance evaluation under various operating conditions and it has been verified that the proposed design can achieve acceptable stack performance at a wide operating range.

오일 분리기에서 $CO_2$/PAG오일 혼합물의 오일 분리특성에 관한 실험적 연구 (An Experimental Study on Oil Separation Characteristics of $CO_2$/PAG Oil Mixture in the Oil Separator)

  • 김경재;이성광;조은영;강병하;김석현
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2008년도 동계학술발표대회 논문집
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    • pp.131-136
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    • 2008
  • The oil separation in an oil separator is one of the most important characteristics for proper compressor operation. In this study, a gravity type of oil separator is used. Oil separation characteristics has been investigated for $CO_2$/PAG mixture in the range of oil concentration 0 to 5 weight-percent and the mixture temperature range of $5^{\circ}C$ to $15^{\circ}C$ and $70^{\circ}C$ to $90^{\circ}C$. The results obtained indicate that the oil separation is increased with an increase in the oil concentration. It is also found that the oil separation in liquid state is increased with an increase in the mixture temperature while the oil separation in gas state is decreased.

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Poly(meta-phenylene isophthalamide)를 이용한 리튬이차전지용 PE 분리막의 고내열화 연구 (A Study on the Improvement of the Thermal Stability of PE Separator for Lithium Secondary Battery Application Using Poly(meta-phenylene isophthalamide))

  • 박민아;라병호;배진영;김병현;최원근
    • 폴리머
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    • 제37권1호
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    • pp.22-27
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    • 2013
  • 본 연구에서는 기존의 이차전지용 폴리에틸렌(PE) 분리막에 poly(meta-phenylene isophthalamide) (Nomex)를 코팅함으로써 뛰어난 내열성을 가진 coated PE 분리막을 제조하였다. 다양한 Nomex 용액 조성과 PE 분리막 코팅 조건에 따라 제조한 분리막의 기계적 및 열적 특성을 열 노출 테스트와 TMA를 이용하여 측정하였고 제조된 코팅 분리막은 기존의 PE 분리막보다 향상된 열 수축률 및 기계적 성질을 보였다. 코팅 분리막의 전기화학적 성질은 이온전도도, 순환 전위-전류법, 충방전 사이클 테스트 등을 이용해 측정하였다.

균일형 유로에서 기포의 거동에 관한 연구 (Study on the Behaivor of Bubbles in Array Type Flow Channels)

  • 정영관
    • 한국수소및신에너지학회논문집
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    • 제24권1호
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    • pp.84-90
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    • 2013
  • The hydrogen or oxygen gas producted by electrolysis become many bubbles in the electrolyte, but exact data on the behavior of these bubbles in the separator of an electrolysis stack didn't become known. In this study, the flow visualization experiment on the behavior of bubbles in the flow pattern of the array type separator is performed by using of a visible alkaline electrolysis stack and a stereoscopic microscope. As the results, a fine size bubbles adhered to the surface of the flow pattern grow to large sized bubbles until each bubble's buoyance is lager than the sum of external force and weight. And then the large bubbles flow into the upper area of the separator. Bubbles adhered to the surface of the vertical flow pattern grow quickly than them adhered to the surface of the horizontal flow pattern. Also, he electrolysis efficiency is declined because many multi-size bubbles occupied the wide volume in the flow pattern.

Flexible poly(vinyl alcohol)-ceramic composite separators for supercapacitor applications

  • Bon, Chris Yeajoon;Mohammed, Latifatu;Kim, Sangjun;Manasi, Mwemezi;Isheunesu, Phiri;Lee, Kwang Se;Ko, Jang Myoun
    • Journal of Industrial and Engineering Chemistry
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    • 제68권
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    • pp.173-179
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    • 2018
  • Electrochemical characterization was conducted on poly(vinyl alcohol) (PVA)-ceramic composite (PVA-CC) separators for supercapacitor applications. The PVA-CC separators were fabricated by mixing various ceramic particles including aluminum oxide ($Al_2O_3$), silicon dioxide ($SiO_2$), and titanium dioxide ($TiO_2$) into a PVA aqueous solution. These ceramic particles help to create amorphous regions in the crystalline structure of the polymer matrix to increase the ionic conductivity of PVA. Supercapacitors were assembled using PVA-CC separators with symmetric activated carbon electrodes and electrochemical characterization showed enhanced specific capacitance, rate capability, cycle life, and ionic conductivity. Supercapacitors using the $PVA-TiO_2$ composite separator showed particularly good electrochemical performance with a 14.4% specific capacitance increase over supercapacitors using the bare PVA separator after 1000 cycles. With regards to safety, PVA becomes plasticized when immersed in 6 M KOH aqueous solution, thus there was no appreciable loss in tear resistance when the ceramic particles were added to PVA. Thus, the enhanced electrochemical properties can be attained without reduction in safety making the addition of ceramic nanoparticles to PVA separators a cost-effective strategy for increasing the ionic conductivity of separator materials for supercapacitor applications.

An Experimental Study on Oil Separation Characteristics of $CO_2$/P AG Oil Mixture in an Oil Separator

  • Kang, Byung-Ha;Kim, Kyung-Jae;Lee, Sung-Kwang
    • International Journal of Air-Conditioning and Refrigeration
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    • 제17권3호
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    • pp.88-93
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    • 2009
  • Lubricant oil is needed in air conditioning and refrigeration system because the compressor requires oil to prevent surface to surface contact between its moving parts, to remove heat, to provide sealing, to keep out contaminants, to prevent corrosion, and to dispose of debris created by wear. Thus, the oil separation in an oil separator is one of the most important characteristics for proper compressor operation. In this study, a gravity type of oil separator is used. Oil separation characteristics have been investigated for $CO_2$/PAG mixture in the range of oil concentration 0 to 5 weight-percent and the mixture temperature range of $0^{\circ}C$ to $15^{\circ}C$ at 50 bar and $70^{\circ}C$ to $90^{\circ}C$ at 80 bar. The results obtained indicate that the oil separation is increased with an increase in the oil concentration. It is also found that the oil separation in liquid state is increased with an increase in the mixture temperature while the oil separation in gas state is decreased.

다양한 형태의 AAO membrane 제조 및 리튬이온 전지의 분리막 응용 연구 (Study on the Fabrication of Various AAO Membranes for the Application of Li-ion Battery Separator)

  • 김문수;임경민;하재윤;김용태;최진섭
    • 한국표면공학회지
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    • 제54권5호
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    • pp.213-221
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    • 2021
  • In order to improve the energy density and safety of Li-ion batteries, the development of a separator with high thermal stability and electrolyte wettability is an important desire. Thus, the ceramic separator to replace the polymer type is one of the most promising materials that can prevent short-circuit caused by the formation of dendrite and thermal deformation. In this study, we introduce the fabrication of various anodic aluminum oxide membranes for the application of Li-ion battery separators with the advantages of improved mechanical/thermal stability, wettability, and a high rate of Li+ migration through the membrane. Two different types of through-holes and branched anodic aluminum oxide membranes are well used in lithium-ion battery separators, however, branched anodic aluminum oxide membranes exhibit the most improved performance with capacity (126.0 mAh g-1 @ 0.3C), capacity drop at the high C-rate (30.6 %), and low internal resistance (8.2 Ω).

분리판의 채널 높이에 따른 1 kWe 급 고체산화물 연료전지 스택 수치 해석 (Numerical Analysis in a 1 kWe SOFC Stack for Variation of the Channel Height in Separators)

  • 윤호원;김영진;이근우;김현진;윤경식;유지행
    • 한국수소및신에너지학회논문집
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    • 제33권5호
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    • pp.550-556
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    • 2022
  • In this study, the flow uniformity was analyzed by performing numerical analysis on the 1 kWe internal manifold type solid oxide fuel cell stack according to the channel height of the separator. Also, it was examined by varying the fuel utilization rate and oxygen utilization rate. From the calculation results, we found that as the channel height of the separator decreased, the pressure drop increased exponentially. In addition, it was found that as the channel height of the separator decreased, the gas flow resistance inside the unit cell increased, and the flow resistance increased the pressure drop, thereby improving the flow uniformity inside the stack. Finally, the calculation results showed that as the fuel and oxygen utilization increased, the flow uniformity also improved.

인자 분석을 통한 전기차 열교환기 분리판용 고강도 알루미늄 판재 성형 연구 (A Study on the Forming Process of High-strength Aluminum Sheet for Electric Vehicle Heat Exchanger Separator Through Parametric Analysis)

  • 정선호;양종훈;김용배;이광진;김봉환;이종섭;배기현
    • 소성∙가공
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    • 제31권2호
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    • pp.57-63
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    • 2022
  • The current study performed formability analysis of a heat exchanger separator for an electric vehicle to apply a high-strength aluminum sheet based on parametric analysis. Mechanical properties for sheet metal forming simulation were evaluated by tensile test, bulge test, and Nakajima test. Two-stage crash forming was established by considering the mass production process using conventional low-strength aluminum sheets. In this study, FEM for the two-stage forming process was conducted to optimize the corner radius and height for improving the formability. In addition, the possibility of a one-stage forming process application was confirmed through FEM. The prototype of the sample was manufactured as FEM results to validate the parametric analysis. Finally, this result can provide a one-stage forming process design method using the high-strength aluminum sheet for weight reduction of a heat exchanger separator for an electric vehicle.