• Title/Summary/Keyword: Metal Hydride

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Rapid Cooling Performance Evaluation of a ZrCo bed for a Hydrogen Isotope Storage (수소동위원소 저장용 ZrCo용기의 급속 냉각 성능 평가)

  • Lee, Jungmin;Park, Jongchul;Koo, Daeseo;Chung, Dongyou;Yun, Sei-Hun;paek, Seungwoo;Chung, Hongsuk
    • Journal of Hydrogen and New Energy
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    • v.24 no.2
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    • pp.128-135
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    • 2013
  • The nuclear fuel cycle plant is composed of various subsystems such as a fuel storage and delivery system (SDS), a tokamak exhaust processing system, a hydrogen isotope separation system, and a tritium plant analytical system. Korea is sharing in the construction of the International Thermonuclear Experimental Reactor (ITER) fuel cycle plant with the EU, Japan, and the US, and is responsible for the development and supply of the SDS. Hydrogen isotopes are the main fuel for nuclear fusion reactors. Metal hydrides offer a safe and convenient method for hydrogen isotope storage. The storage of hydrogen isotopes is carried out by absorption and desorption in a metal hydride bed. These reactions require heat removal and supply respectively. Accordingly, the rapid storage and delivery of hydrogen isotopes are enabled by a rapid cooling and heating of the metal hydride bed. In this study, we designed and manufactured a vertical-type hydrogen isotope storage bed, which is used to enhance the cooling performance. We present the experimental details of the cooling performances of the bed using various cooling parameters. We also present the modeling results to estimate the heat transport phenomena. We compared the cooling performance of the bed by testing different cooling modes, such as an isolation mode, a natural convection mode, and an outer jacket helium circulation mode. We found that helium circulation mode is the most effective which was confirmed in our model calculations. Thus we can expect a more efficient bed design by employing a forced helium circulation method for new beds.

Thermal Management of a Nickel/Metal Hydride Battery (Nickel/Metal Hydride 전지의 열관리기술 개발)

  • Kim, Junbom
    • Applied Chemistry for Engineering
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    • v.8 no.4
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    • pp.667-672
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    • 1997
  • Thermal behavior of high capacity Nickel/Metal hybride battery in analyzed using the NISA software which is based on the three dimensional finite element method. Differential energy balance equation is used for the conduction heat transfer of the battery, while convective heat transfer equation is used for the interface between the battery and air. Heat generation rate and convective heat transfer coefficient are tested as variables to investigate thermal behavior, and the generalized equation for maximum temperature inside the battery is developed. The abrupt rise of the battery temperature due to the quick charge or discharge can be prevented from the use of metallic cooling fin. In addition, temperature augmentation of the battery is negligible when the low thermal conductive and thin insulating material is used outside of the battery case.

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A Study on the Electrochemical and Thermodynamic Properties of Hydrogen Absorbing Alloys (수소저장합금의 전기화학 및 열역학적 특성에 관한 연구)

  • Park, Chan-Kyo;Cho, Tae-Hwan
    • Journal of Hydrogen and New Energy
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    • v.5 no.2
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    • pp.65-71
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    • 1994
  • Electrochemical and thermodynamic properties of $MmNi_5$ and the related alloys for nickel-metal hydride battery(Ni-MH) were studied in terms of the equilibrium hydrogen pressure. $MmNi_5$ alloy with high equilibrium hydrogen pressure(10~20atm at room temperature), which is usually difficult to charge, was substituted for Al in part. Partial substitution of Al made not only the equilibrium pressure to be reduced remarkably, but also the enthalpy change depending on the formation of metal hydride to be agreed to the value in gas phase reaction and electrochemical reaction. Besides the composition of Al which can be given the maximum discharge capacity was turned out to be between the 0.5~1.0 atoms of Al.

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Railway System Standby Power Nickel Metal Hydride Battery (철도시스템비상전원용 니켈수소(NiMH)전지)

  • Kim, Sung-Yong;Park, Dong-Pil
    • Journal of the Korean Society for Railway
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    • v.12 no.6
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    • pp.873-877
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    • 2009
  • In order to use railway system standby power, produced 160Ah NiMH battery that would be able to substitute the lead acid battery or NiCd battery form which contain the toxic material in environment, using parallel connected 80Ah NiMH battery. And in order to develop proper electrode in the 160Ah NiMH battery, tested high rate discharge performance of the ternary electrolyte. 160Ah NiMH battery evaluated the various test in order to use railway system standby power.

Development of Ti-Fe-X metal hydride electrode by mechanical alloying (기계적 합금화법에 의한 Ti-Fe-X계 수소 저장합금의 제조에 관한 연구)

  • Ha, Chang-Jin;Lee, Gyeong-Seop
    • Korean Journal of Materials Research
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    • v.5 no.1
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    • pp.112-122
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    • 1995
  • Metal hydride alloys of TiFe based system have been produced by mechanical alloying(MA) method and their electrochemical characteristics have been evaluated for application for Ni/MH battery electrode. These alloys became amorphous after 36hrs ball milling and easily activated electrochemically. All MA amorphous alloys reached at the first charge/discharge cycle the maximum capacity which was 2-3 times higher than the crystalline state. But their cyclic lives were much inferior to the crystalline state. Alloying elements such as Ni, Co, Cr, Mo substituting Fe greatly improved the capacity and 180 mAh/g capacity was obtained in an alloy of TiFe_{0.6}Ni_{0.1}Co_{0.1}Cr_{0.1}Mo_{0.1}$.

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Thermodynamic Efficiency of Metal Hydride Heat Pump (금속수소화물을 이용한 히트펌프의 열역학적 효율)

  • Park, C.K.;Komazaki, Y.;Suda, S.
    • Journal of Hydrogen and New Energy
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    • v.3 no.2
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    • pp.1-7
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    • 1992
  • New type of metal hydride heat pump (MHHP) combined with hydrogen compressor was constucted for cooling purpose. A model for calculating the coefficient of performance (COP) is presented for MHHP which consisted of two different stages (enforced and natural stage), and compared with the experimental results. A concept of adiabatic compression work is introduced in the model on the basis of Carnot reversible analysis and the dependence of COP on the various operational parameters is discussed.

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Selective Reduction of Organic Compounds with Non-Free Hydride Reducing Agents

  • Cha, Jin Soon
    • Journal of Integrative Natural Science
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    • v.1 no.3
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    • pp.192-194
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    • 2008
  • A series of non-free hydride reducing systems containing boron or aluminum atom, which possess no metal-hydride bond but an available hydrogen at a branched ${\beta}$-position, has been applied to the selective reduction (chemo--, regio-, and stereoselective reduction) of organic compounds. The systems, comprised of diisopinocampheylborane and diisobutylalane derivatives, exhibited almost perfect selectivities in the reduction of aldehydes and ketones. The characteristics features of this systems leading to a perfect transformation have been depicted in this report, especially in the 1) Reduction of ${\alpha}$,${\beta}$-Unsaturated Carbonyl Compounds to Allylic Alcohols via 1,2-Reduction, 2) Chemoselective Reduction between Structurally Different Carbonyl Compounds, and 3) Stereoselective Reduction of Cyclic Ketones.

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