• Transactions of the Korean hydrogen and new energy society
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• v.23 no.4
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• pp.316-322
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• 2012

A fuel cell vehicle has the hydrogen detection sensors for checking the hydrogen leakage because it use hydrogen for its fuel and can't use a odorant to protect the fuel cell stack. To verify the hydrogen safety of leakage we select the high possible leak points of fittings in hydrogen storage system and test the leaking behavior at them. The hydrogen leakage flow rate is 10, 40, 118 NL/min and the criterion for maximum hydrogen leakage is based on allowing an equivalent release of combustion energy as permitted by gasoline vehicles in FMVSS301. There are total 18EA hydrogen leakage detection sensors installed in test system. we acquire the hydrogen leakage detection time and determine the ranking. Hydrogen leakage detection time decrease when hydrogen leakage flow rate increase. The minimum hydrogen leakage detection time is about 3 seconds when the flow rate is 118NL/min. In this study, we optimize hydrogen sensor position in fuel cell vehicle and verify the hydrogen leakage safety because there is no inflow inside the vehicle.

• Transactions of the Korean hydrogen and new energy society
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• v.7 no.1
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• pp.19-28
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• 1996

Ti-Mn based hydrogen storage alloy were modified by substituting alloying elements such as Zr, V and Ni in order to design a high capacity MH electrode for Ni/MH rechargeable battery. When V was substituted in Ti-Mn binary system, the crystal structure was maintained as $Cl_4$ Laves phase at a composition of $Ti_{0.2}V_{0.4}Mn_{0.4}$ and $Ti_{0.4}V_{0.2}Mn_{0.4}$ and equilibrium pressure decreased below 1 atm without decreasing hydrogen storage capacity considerably. It was found that Ni should be included in Ti-V-Mn alloy in order to hydrogenate it electrochemically in KOH electrolyte. But substitution of Ni for Mn in Ti-V-Mn system caused the increase of equilibrium pressure above 1atm and decrease of hydrogen storage capacity. Zr was able to increase the reversible hydrogen storage capacity of Ti-V-Mn-Ni alloy without considerable change of hydrogenation properties. The electrochemical discharge capacity of Ti-Zr-V-Mn-Ni system were in the range of 350 - 464mAh/g and among them $Ti_{0.8}Zr_{0.2}V_{0.5}Mn_{0.5}Ni_{1.0}$ alloy had $Cl_4$ Laves single phase and very high electrochemical discharge capacity of 464mAh/g.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.5
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• pp.534-540
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• 2022

Liquid hydrogen has the best storage capacity per unit mass and is economical among storage methods for using hydrogen as fuel. As the demand for hydrogen increases, the need to develop a storage and supply system of liquid hydrogen is emphasizing. In order to liquefy hydrogen, it is necessary to pre-cool it to a maximum inversion temperature of -253℃. The Gifford-McMahon (GM) refrigerator is the most reliable and commercialized refrigerator among small-capacity cryogenic refrigerators, which can extract high-efficiency hydrogen through liquefied hydrogen production and boil of gas re-liquefaction. Therefore, in this study, the optimal conditions for liquefying gas hydrogen were sought using the GM cryocooler. The process was simulated by PRO/II under various cooling capacities of the GM refrigerator. In addition, the flow rate of hydrogen was calculated by comparing with specific refrigerator capacity depending on the pressure and flow rate of a refrigerant medium, helium. Simulations were performed to investigate the optimal values of the liquefaction flow rate and compression pressure, which aim for the peak refrigeration effect. Based on this, a liquefaction system can be selected in consideration of the cycle configuration and the performance of the refrigerator.

• Transactions of the Korean hydrogen and new energy society
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• v.35 no.3
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• pp.300-309
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• 2024

Hydrogen utilization in the transportation sector, which relies on fossil fuels, can significantly reduce greenhouse gas by using to hydrogen fuel cell vehicles, and its adoption depends performance of hydrogen refueling station. The present study developed a model to simulate the back-to-back filling process of heavy duty hydrogen fuel cell vehicles at hydrogen refueling stations using a cascade method. And its quantitatively evaluated hydrogen refueling station performance by simulating various mass flow rates and storage tank capacity combinations, analyzing vehicle state of charge (SOC) of vehicles. In the cascade refueling system, the capacity of the high-pressure storage tank was found to have the greatest impact on the reduction of filling time and improvement of efficiency.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.179-185
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• 2005

Nowadays, study about hydrogen fuel which consist of hydrogen extraction process, reforming, fuel cell equipment, and receptacle are flourish all over the world. Currently, Korea hydrogen station is still underdevelopment. Yet the most important part such as hydrogen compressor has not been develop. Therefore, if the high pressure compressor for hydrogen have been developed by domestic technology. In the future many benefit can be gain instead of importing. Such as many hydrogen station can be built in Korea, and also Korea will be able to provide hydrogen system for worldwide. This study is going to analysis hydrogen compressor in order to store high pressure hydrogen. This is almost approach practical use of tile hydrogen storage method.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.4
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• pp.347-355
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• 2019

As a solution to the growing concern on the global warming, researches are being actively carried out to apply carbon dioxide capture and storage technology to power generation systems. In this study, the integrated gasification combined cycle (IGCC) adopting oxy-combustion carbon capture was modeled and the effect of replacing the conventional air separation unit (ASU) with the ion transport membrane (ITM) on the net system efficiency was analyzed. The ITM-based system was predicted to consume less net auxiliary power owing to an additional nitrogen expander. Even with a regular pressure ratio which is 21, the ITM-based system would provide a higher net efficiency than the optimized ASU-based system which should be designed with a very high pressure ratio around 90. The optimal net efficiency of the ITM-based system is more than 3% higher than that of the ASU-based system. The influence of the operating pressure and temperature of the ITM on system efficiency was predicted to be marginal.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.04a
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• pp.203-206
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• 2005

The objective of study on composite cylinder for alternative fuel vehicle is to develop safe, efficient, and commercially viable, on-board fuel storage system for the fuel cell vehicle or natural gas vehicle that use highly compressed gaseous fuel such as hydrogen or natural gas. This study presents the whole procedure of development and certification of a type 3 composite cylinder of 207bar service pressure and 70 liter water capacity, which includes design/analysis, processing of filament winding, and validation through various testing and evaluation. Design methods of liner configuration and winding patterns are presented. Three dimensional, nonlinear finite element analysis techniques are used to predict burst pressure and failure mode. Design and analysis techniques are verified through burst and cycling tests. The full qualification test methods and results for validation and certification are presented.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.383-386
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• 2007

This paper describes the design and integration of the wind- fuel cell hybrid system. The hybrid system components included a wind turbine, an electrolyzer (for generation of H2), a PEMFC (Proton Exchange Membrane Fuel Cell), storage system and BOP (Balance of Plant) system. The energy input is entirely provided by a wind turbine. A DC-DC converter controls the power input to the electrolyzer, which produces hydrogen and oxygen form water. The hydrogen used the fuel for the PEMFC. The hydrogen is compressed and stored in high pressure tank by hydrogen gas booster system.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.1
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• pp.39-46
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• 2024

As the development of hydrogen vehicles has accelerated in recent years, it is necessary to develop a storage tank for hydrogen fueling stations capable of high-pressure charging, and for this purpose, a new system with a compressor-embedded refueling tank is required. In this study, the parametric study of shape design based on strength performance evaluation was carried out to find the optimal shape design of bellows, the core component of compressor-embedded refueling tank for a newly developed hydrogen refueling station capable of high-pressure charging above 1,000 bar. The design factors for parametric study were contour shape and radius of bellows, and the performance factors were the maximum stress and the gap distance in the contact direction. In the shape design of the compressor bellows for hydrogen refueling station considered in this study, it was found that adjusting the contour radius is an appropriate design method to improve the compression performance and structural safety.

• Korean Chemical Engineering Research
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• v.49 no.5
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• pp.644-651
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• 2011

Storing hydrogen in solid state hydride is one of the best promising methods for the future hydrogen economy. The total performance of such systems depends on the rate at which the amount of mass and heat migration is supplied to solid hydride. Therefore, an accurate modeling of the heat and mass transfer is of prime importance in optimizing the design of such systems. In this work, Hydrogen storage in Pt-CNTs hydrogen reactor has been intensively investigated by solving 2 dimensional mathematical models. Using a CFD computer software, systematic studies have been performed to elucidate the effect of heat and mass transfer during hydrogen charging periods. It was revealed that the optimized design of hydrogen storage vessel can prevent the increase of system temperature and the charging time due to the convective cooling effects inside the vessels at even high charging pressure. Because none has reported the critical issues of heat and mass transfer for CNT based hydrogen storage system, this work can support the first insight of the optimal design for solid state hydrogen storage system based on CNT in the near future.