• 제목/요약/키워드: AE 에너지

검색결과 255건 처리시간 0.022초

세라믹필터 역세정을 위한 노즐 사이즈 최적화 (The optimization of nozzle size for pulse cleaning of ceramic filter)

  • 최주홍;김진형;지화창;우량;사공경민;김영애
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2007년도 춘계학술대회
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    • pp.796-799
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    • 2007
  • In the bench scale test unit consisting of four commercial filter elements, the traces of the transient pressure around the nozzle and overpressure in the filter cavity were measured to estimate the effect of nozzle on pulse cleaning. For the given pulse cleaning system, the convergent nozzle displayed better performance than the straight one. The optimum ratio of outlet to inside diameter of convergent nozzle was determined, which minimized the pulse gas consumption and maximized the entrainment effect. The angle and height of nozzle convergent part was also optimum operational condition, which is meaningful to the industrial applying.

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시동/정지 반복에 따른 고분자전해질 연료전지의 성능 저하에 관한 연구 (A Study on Performance Degradation of PEMFC by Repetitive Startup/Shutdown Cycling)

  • 조유연;조은애;김정현
    • 한국수소및신에너지학회논문집
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    • 제20권4호
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    • pp.317-322
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    • 2009
  • To investigate degradation mechanism of PEMFC operated with repetitive startup/shutdown cycling, i-V characteristics, impedance, cyclic voltamograms were measured. OCV decreased from 0.967 to 0.951 V while the cell voltage at 800mA/$cm^2$ from 0.657 to 0.563V, implying that the electrodes rather than membrane electrolyte was damaged during the cycling operation. Electrochemical analyses supported that the performance degradation could be mainly attributed to degradation of the electrodes such as a decrease in electrochemical active surface area rather than degradation of membrane.

TiN이 코팅된 316 스테인리스강 분리판을 이용한 고분자전해질 연료전지의 성능에 관한 연구 (A Study on the Performance of PEMFC Using the TiN-Coated 316 Stainless Steel Bipolar Plates)

  • 조은애
    • 한국수소및신에너지학회논문집
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    • 제14권4호
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    • pp.291-297
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    • 2003
  • As an alternative bipolar plate material for polymer electrolyte membrane fuel cell (PEMFC), TiN-coated 316 stainless was evaluated in terms of electrical contact resistance and water contact angle. Performance and lifetime of the TiN-coated 316 bipolar plates were measured in comparison with those of graphite and bare 316 bipolar plates. At a cell voltage of 0.6 V, current density of the single cells using graphite, AISI 316, and TiN/316 bipolar plates was 996, 796, and $896mA/cm^2$, respectively. By coating 316 stainless steel with TiN layer, performance degradation rate determined to be the voltage degradation rate at a cell voltage of 0.6 V was reduced from 2.3 to 0.43 mV/h.

고온환경하에서 지르코니아/니켈 소결재의 기계적 특성평가 (Evaluation of Mechanical Properties of Zirconia/Ni Sintering Materials at High Temperature)

  • 김연직
    • 한국재료학회지
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    • 제6권9호
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    • pp.972-978
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    • 1996
  • 본 논문에서는 1673K에서 소결한 PSZ/Ni 복합재에 대한 종 탄성계수, 파괴강도, 파괴에너지 등의 기계적 특성을 평가하기 위해, 개량형 소형펀치시험을 행한 결과에 대해 논의한다. 또한 파면관찰과 AE법을 통해 이들 재료의 고온환경에서의 미시파괴과정도 조사하였다. 시험온도는 293K, 1073K, 1273K, 1473K의 4종류로 하였으며, PSZ/Ni 복합재료의 체적 조성비도 80/20, 60/40, 40/60, 20/80의 4종류이다. 이들 실험결과로부터, 1073K이상의 고온에서 Ni 함량이 60%인 PSZ/Ni 복합재가 파괴강도 및 파괴에너지가 가장 우수한 것을 알았다. 파면관찰에 의하면 이 재료의 조성비에서 파고거동이 취성으로부터 연성으로 천이하는 것을 확인할 수 있었다.

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Electrochemical characterization of supercapacitors based on carbons derived from Sorona activated by ZnCl2

  • ;;김애란;남기석;유동진
    • 에너지공학
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    • 제21권3호
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    • pp.309-314
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    • 2012
  • Carbons derived by the pyrolysis of Sorona activated by $ZnCl_2$ in the ratio of 1:20 and non-porogen Sorona carbons are used as the electrode materials in asymmetric electrochemical supercapacitors and electrochemical behavior is investigated. Scanning electron microscopy (SEM) reveals the porogen free carbons show a flake-like structure and the $ZnCl_2$-treated Sorona carbons have a loose, disjoint structure without any particular shape. Cyclic voltammetric (CV) studies show specific prolate rectangular shape and gives good capacitive properties.

냉시동시 채널 막힘이 고분자전해질연료전지의 장기성능에 미치는 영향 (Effects of channel blockages during cold start up on durability of proton exchange membrane fuel cell)

  • 이상엽;김형준;조은애;장종현;임태훈
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2008년도 추계학술대회 논문집
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    • pp.33-36
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    • 2008
  • Cell degradation when anode channels are blocked during cold start up was tested and measured. Proton exchange membrane fuel cell (PEMFC) stacks with several configurations of channel blockages were operated and decay in performance was analyzed. When only channels near hydrogen inlet were blocked, performance was rarely changed. In contrast, significant cell reversal occurred and considerable amount of $CO_2$ was produced when all channels near inlet and outlet were blocked. In the case, it was also observed that performance was severely decreased in the area where hydrogen was not supplied sufficiently.

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${\gamma}$-FIB를 이용한 산소 유량에 따른 ITO (Indium Tin Oxide)의 Energy Band Structure 측정

  • 이경애;김동해;권기청;엄환섭;최은하
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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    • pp.191-191
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    • 2011
  • 최근 투명전극 연구는 태양전지 및 디스플레이, LED 등 많은 분야에서 응용되며 또한 기술 개발이 활발하다. 그 중 전기 전도도가 우수하면서 밴드갭이 2.5 eV 이상으로 가시광 영역에서 투명하기 때문에 디스플레이의 투명전극으로 ITO (Indium Tin Oxide)가 많이 사용되고 있다. 본 실험에서는 RF magnetron sputtering법을 이용한 ITO의 증착시 산소 유량을 달리하여 제작한 박막의 Energy Band Structure를 ${\gamma}$-FIB system을 이용하여 측정하였다. ITO에 이온화 에너지가 24.5 eV인 He Ion source를 주사하였을 때 Auger self-convolution을 통해 이차전자의 운동 에너지 분포를 구하고, 이를 통해 ITO 내의 Energy Band Structure를 실험적으로 측정하였다.

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연료전지용 양이온 전도성이 증가된 디페닐 단위를 갖는 블록공중합체 혼성막 제조 및 특성 (Preparation and Characterization of Hybrid Membrane for Block Copolymer Containing Diphenyl Unit Increasing Cationic Conductivity for Fuel Cells)

  • 김애란
    • 한국수소및신에너지학회논문집
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    • 제28권5호
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    • pp.465-470
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    • 2017
  • Sulfonated fluorinated block copolymers having diphenyl units were mixed with the sulfonated cationic conductive polymers at an optimum mixing ratio to form hybrid membranes for fuel cells and their characteristics were studied. 2D and 3D AFM topology analysis confirmed that the number of hydrophilic units in the hybrid membrane was improved. Through the FE-SEM, the microstructure of the hybrid membrane implied hydrogen bonding and pi-pi interactions, and EDAX confirmed carbon, oxygen, sulfur, and fluorine. The thermogravimetric analysis showed that the hybrid membrane was thermally stable and the hydrophilicity of the hybrid membrane was increased by the contact angle of water droplets. As a result, it was confirmed that the cation conductivity increased by a factor of 1.8 times as the number of acidic domains in the hybrid film increased.

첨가제를 이용한 촉매슬러리 조성 안정화 및 열-압착 공정 최적화 통한 PEMFC용 MEA 개발 (Effects of Additives and Hot-Pressing Conditions on the Surface and Performance of MEAs for PEMFCs)

  • 장현숙;조은애
    • 한국수소및신에너지학회논문집
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    • 제21권5호
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    • pp.398-404
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    • 2010
  • Process conditions for MEA fabrications have significant effects on properties and performance of the MEAs for PEMFCs. In this study, effects of additives on the surface properties of the MEA was investigated to improve homogeneity of the coated catalyst layer. Another parameter that affects on characteristics of the MEAs is hot-pressing condition. Hot pressing condition was optimized by using DOE (design of experiment) method.