• 제목/요약/키워드: Metal Hydride

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FPGA based POS MPPT control for a small scale charging system of PV-nickel metal hydride battery (FPGA를 이용한 소형 태양광 발전 니켈 수소 전지 충전 시스템의 POS MPPT 제어)

  • Lee, Hyo-Geun;Seo, Hyo-Ryong;Kim, Gyeong-Hun;Park, Min-Won;Yu, In-Keun
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1306-1307
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    • 2011
  • Recently, the small scale photovoltaic (PV) electronic devices are drawing attention as the upcoming PV generation system. The PV system is commonly used in small scale PV applications such as LED lighting and cell phone. This paper proposes photovoltaic output sensorless (POS) maximum power point tracking (MPPT) control for a small scale charging system of PV-nickel metal hydride battery using field-programmable gate array (FPGA) controller. A converter is connected to a small scale PV cell and battery, and performs the POS MPPT at the battery terminal current instead of being at the PV cell output voltage and current. The FPGA controller and converter operate based on POS MPPT method. The experimental results show that the nickel metal hydride battery is charged by the maximum PV output power.

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Hydrogen Supplying System using Metal Hydride (금속 수소화물을 이용한 수소공급시스템)

  • Bae, Sang-Chul;Katsuta, Masafumi
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.13-19
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    • 2007
  • To find out the optimum design of hydrogen storage and supply tank using Metal Hydride (briefly MH) and to make clear the performance characteristics under various conditions are our research purpose. In order to use the low-temperature exhaust heat, $LaNi_{4.7}Al_{0.3}$ which operates under the low pressure of 1 MPa is chosen, and we measure the basic properties, namely density, specific heat, PCT(Pressure-Concentration-Temperature) characteristics, and effective thermal conductivity. Then, a numerical calculation model of hydrogen storage using MH alloy is suggested and this thermal diffusion equation of model is solved by the backward difference method. This calculation results are compared with the experimental results of the systems which installed 1kg MH alloy and, it is found out that our calculation model can well predict the experimental results. By the experimental using MH alloy, it is recognized that the hydrogen flow rate can control by the step adjustment of brine temperature.

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Hydrogen Isotopes Accountancy and Storage Technology (수소동위원소 계량·공급기술)

  • Koo, Dae-Seo;Chung, Hong-Suk;Chung, Dong-You;Lee, Jung-Min;Yun, Sei-Hun;Cho, Seung-Yon;Jung, Ki-Jung
    • Journal of Hydrogen and New Energy
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    • v.23 no.1
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    • pp.49-55
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    • 2012
  • Hydrogen isotopes accountancy and storage are important functions in a nuclear fusion fuel cycle. The hydrogen isotopes are safely stored in metal hydride beds. The tritium inventory of the bed is determined from the decay heat of tritium. The decay heat is measured by circulating helium through the metal hydride bed and measuring the resultant temperature increase of the helium flow. We are reporting our preliminary experimental results on the hydrogen isotopes accountancy and storage performance in a metal hydride bed.

The effect of particle size on hydrogen storage of Mm-based alloys (Mn계 합금의 수소 저장에 대한 입자크기의 영향)

  • Park, Chan Kyo;Bae, Jang Soon;Cho, Bum Sik
    • Journal of Hydrogen and New Energy
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    • v.11 no.4
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    • pp.171-177
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    • 2000
  • Metal hydride used as hydrogen storage material usually needs the activating process to store the hydrogen at high temperature or high pressure. In general as the particle size of metal hydride becomes smaller, approached to the micro, furthermore, nano scale, storage ability and reaction kinetics are reported to be increased, because the specific surface is extremely increased. But the experimental results demonstrated that the optimum particle size is existed for the best absorbing performance, opposite to the usual expectation. This results from the particles to be come amorphous with their approaching to micro and nano scale, in the storage site within the metal hydride lattice is decreased, which is proved by XRD and SEM.

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FPGA based POS MPPT Control for a Small Scale Charging System of PV-nickel Metal Hydride Battery (FPGA를 이용한 소형 태양광 발전 니켈 수소 전지 충전 시스템의 POS MPPT 제어)

  • Lee, Hyo-Guen;Seo, Hyo-Ryong;Kim, Gyeong-Hun;Park, Min-Won;Yu, In-Keun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.1
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    • pp.80-84
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    • 2012
  • Recently, the small scale photovoltaic (PV) electronic devices are drawing attention as the upcoming PV generation system. The PV system is commonly used in small scale PV applications such as LED lighting and cell phone. This paper proposes photovoltaic output sensorless (POS) maximum power point tracking (MPPT) control for a small scale charging system of PV-nickel metal hydride battery using field-programmable gate array (FPGA) controller. A converter is connected to a small scale PV cell and battery, and performs the POS MPPT at the battery terminal current instead of being at the PV cell output voltage and current. The FPGA controller and converter operate based on POS MPPT method. The experimental results show that the nickel metal hydride battery is charged by the maximum PV output power.

A Numerical Investigation of Hydrogen Absorption Reaction Based on ZrCo for Tritium Storage (I) (삼중수소 저장을 위한 ZrCo 저장재에서의 수소 흡장에 대한 수치해석적 연구 (I))

  • Yoo, Haneul;Yun, Seihun;Chang, Minho;Kang, Hyungoo;Ju, Hyunchul
    • Journal of Hydrogen and New Energy
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    • v.23 no.5
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    • pp.448-454
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    • 2012
  • In this paper, a three-dimensional hydrogen absorption model is applied to a thin double-layered annulus ZrCo hydride bed and validated against the temperature evolution data measured by Kang et al. The present model reasonably captures the bed temperature evolution behavior and the 99% hydrogen charging time. The equilibrium pressure expression for hydrogen absorption on ZrCo is derived as a function of temperature and the H/M atomic ratio based on the pressure-composition isotherm data given by Konishi et al. In addition, this present model provides multi-dimensional contours such as temperature and H/M atomic ratio in the thin doublelayered annulus metal hydride region. This numerical study provides fundamental understanding during hydrogen absorption process and indicates that efficient design of the metal hydride bed is critical to achieve rapid hydrogen charging performance. The present three-dimensional hydrogen absorption model is a useful tool for the optimization of bed design and operating conditions.

Numerical prediction of hydrogen storaging performance of finned metal hybride beds (휜이 달린 수소저항합금 베드의 수소저장 성능의 수치적 예측)

  • Kim, Myeong-Chan;Lee, Sang-Yong;Gu, Jae-Hak
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.22 no.4
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    • pp.520-529
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    • 1998
  • Heat and mass transfer behaviors of metal hydride beds were predicted by solving a set of volume-averaged equations numerically both for the gas (hydrogen) and the solid(metal hydride) phases. Time variations of temperature and hydrogen concentration ratio distributions were obtained for internally cooled, cylindrical-shaped beds with metal(aluminum) fins imbedded in them. Also, time variations of the space-averaged hydrogen concentration ratio were obtained. Temperature and velocity of the coolant, hydrogen pressure at the gas inlet, and the fin spacing were taken as the parameters. The hydrogen absorption rate increases with the higher velocity and the lower temperature of the coolant, and with the decrease of the fin spacing. Increasing of the hydrogen pressure at the gas inlet also promotes the rate of absorption though the increasing rate gradually slows down. The amount of the hydrogen storage per unit volume of the bed decreases with the tighter fin spacing despite of the higher absorption rate ; therefore, there should be an optimum fin spacing for a given volume of the system and the amount of the hydrogen storage, in which the absorption rate is the highest.

An Efficient Preparation of 4-Nitrosoaniline from the Reaction of Nitrobenzene with Alkali Metal Ureates

  • Park, Jaebum;Kim, Hyung Jin
    • Journal of the Korean Chemical Society
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    • v.60 no.4
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    • pp.251-256
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    • 2016
  • This paper describes the synthesis of alkali metal salts of urea (ureates) and their application to the direct preparation of 4-nitrosoaniline from nitrobenzene via nucleophilic aromatic substitution of hydrogen. Sodium and potassium ureates were readily prepared from the reaction of urea with sodium hydride, metal methoxides, and metal hydroxides. The effect of ureates as nucleophiles on the conversion of nitrobenzene to 4-nitrosoaniline was investigated and compared with that of a urea-metal hydroxide mixture. It was found that the ureates were superior for producing 4-nitrosoaniline owing to their higher thermal stability of the ureate. The ureate obtained from the treatment of urea with sodium hydride gave the highest yield for the preparation of 4-nitrosoaniline. The ureates generated from the reaction of urea with metal hydroxide also gave high yields of 4-nitrosoaniline. Catalytic hydrogenation of 4-nitrosoaniline afforded polymer-grade 1,4-benzenediamine in quantitative yield.

Some Recommended Procedures for Conversion of Carboxylic Acid and Its Derivatives to Aldehydes by Metal Hydride Reductions

  • Cha, Jin Soon
    • Journal of Integrative Natural Science
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    • v.5 no.2
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    • pp.84-90
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    • 2012
  • Some recommended procedures for obtaining aldehydes from carboxylic acid itself and its derivatives, which have been developed in relatively recent years, are summarized. Such procedures should provide a new practical methodology to synthesize the desired aldehyde products in high yields.

The Properties of the Metal Hydride electrodes prepared by Silicon Sealant (Si-sealant를 이용하여 제조한 금속수소화물 전극의 특성)

  • CHOI, Jeon;PARK, Choong-Nyeon
    • Journal of Hydrogen and New Energy
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    • v.4 no.2
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    • pp.23-28
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    • 1993
  • The $(LM)Ni_{4.5}Co_{0.1}Mn_{0.2}Al_{0.2}$ hydrogen storage alloy powders were conducted 25wt% electroless copper plating in an acidic bath. For the preparation of a hydride electrodes, the copper coated alloy powder was mixed with Si-sealant(organosilicon) and compacted with $6t/cm^2$ at room temperature. The electrode characteristics were examined through electrochemical measurements in a half cell. As a sealant contents increased, the initial discharge capacity of si-sealant bounded electrode was lower and the activation rate in high current density was slower. For extended cycles, however, the electrodes with the Si-sealant were superior in a high rate discharge and useful range of temperature over the sealant-free electrode. In addition, the cycle life increased with increasing the amount of Si-sealant added. It can be suggested from the results that the Si-sealant as a binder could be applied to the preparation of the metal hydride electrode.

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