• Journal of Hydrogen and New Energy
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• v.1 no.1
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• pp.58-65
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• 1989

• Journal of the Korean Institute of Gas
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• v.15 no.2
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• pp.63-68
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• 2011

As an effective utilization of biomass, organic wastes and coal, attention has been made to use syngas to a reciprocating engine to generate power. However, significant component variation of syngas depending upon origin and gasification conditions, and its lower heating value than that of LPG and CNG can create difficulties in stable engine operation. Thus it is necessary to address these issues in order to successfully develop power generation engines. As a primary step to resolve these problems, effects of H2 content variation in syngas on engine performance and emission characteristics were discussed in this study. The results show that as H2 % in syngas increases, more stable combustion was achieved with retarded MBT spark timing and engine efficiency becomes maximum with syngas of 10% H2. In addition, NOx emission increased while THC emission decreased as H2 % rises in the syngas.

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.22-27
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• 2015

Hydrogen features highest energy density per mass and is expected to be desirable as a fuel of HALE(High altitude long endurance) UAV(Unmanned aerial vehicle). A reciprocating internal combustion engine is known to be a reliable and economic power source for this kind of UAV. Therefore, the combination of hydrogen and engine is worth of doing research. Test bench with 2.4L Spark-Ignited engine was prepared for the experiment in which start and combustion characteristics at idle condition were examined in this study. Stable hydrogen supply system and a universal ECU(Engine control unit) were also utilized for the test engine. Equivalence ratio and spark timings at idle operation were investigated and compared to the data of gasoline engine. The results will be a starting point for full-scale research of hydrogen engine for HALE UAV.

• Journal of Hydrogen and New Energy
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• v.33 no.4
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• pp.284-292
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• 2022

Hydrogen is promising a candidate for energy supporting the carbon neutrality policy for greenhouse gas reduction, which is being promoted in several countries, including Korea. Although challenging efforts-such as lowering the costs of green hydrogen production and fuel cells-remain, hydrogen fuel cell electric vehicles (FCEVs) are expected to play a significant role in the energy transition from fossil fuels to renewable energy. In line with this objective, the hydrogen FCEV working group in the International Organization for Standardization (ISO) compiled and revised international standards related to hydrogen refueling stations as of 2019. A well-established hydrogen quality management system based on the standard documents will increase the reliability of hydrogen charging stations and accelerate the use of FCEVs. In this study, among the published ISO standards and other references, the main requirements for managing charging stations and developing related techniques were summarized and explained. To respond preemptively to the growing FCEV market, a continuous hydrogen quality monitoring method suitable for use at hydrogen charging stations was proposed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.219-221
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• 2011

This paper reports the development trend of small fuel cell unmanned aerial vehicles. Development method of a fuel cell propulsion system for small unmanned aerial vehicles is proposed and discussed, such as the lightweight fuel cell stack development, liquid fuel-based hydrogen storage/generation, and fuel cell system technology.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.4
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• pp.417-422
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• 2010

Low temperature diesel combustion was achieved via a combination of late injection timing ($8.5^{\circ}$ CA BTDC to $0.5^{\circ}$ CA BTDC) and heavy exhaust gas recirculation (37% to 48%) with ultra low sulfur Swedish diesel fuel in a 1.7L common rail direct injection diesel engine. When injection timing is retarded at a certain exhaust gas recirculation rate, the particulate matter and nitrogen oxides decease simultaneously, while the hydrocarbon and carbon monoxide increase. Hydrocarbon speciation by gas chromatography using a flame ionization detector reveals that the ratio of partially burned hydrocarbon, i.e., mainly alkenes increase as the injection timing is retarded and exhaust gas recirculation is increased. The two most abundant hydrocarbon species are ethene which is a representative species of partially burned hydrocarbons, and n-undecane, which is a representative species of unburned hydrocarbons. They may be used as surrogate hydrocarbon species for performing a bench flow reactor test for catalyst development.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.5
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• pp.528-532
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• 2007

The generation of high-purity hydrogen from hydrocarbon fuels is essential for efficient operation of fuel cell. In general, most feasible strategies to generate hydrogen from hydrocarbon fuels consist of a reforming step to generate a mixture of $H_2$, CO, $CO_2$ and $H_2O$(steam) followed by water gas shift(WGS) and CO clean-up steps. The WGS reaction that shifts CO to $CO_2$ and simultaneously produces another mole of $H_2$ was carried out in a two-stage catalytic conversion process involving a high temperature shift(HTS) and a low temperature shift(LTS). In the WGS operation, gas emerges from the reformer is taken through a high temperature shift catalyst to reduce the CO concentration to about $3\sim4%$ followed to about 0.5% via a low temperature shift catalyst. The WGS reactor was designed and tested in this study to produce hydrogen-rich gas with CO to less than 0.5%.

• Journal of the Korean Electrochemical Society
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• v.11 no.1
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• pp.22-32
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• 2008

Because of an emerging importance of clean energy, fuel cells are attract more attention due to their ability to produce high efficient power without any harmful emission. Fuel cells are energy conversion device with directly convert chemical energy into electrical energy by the chemical reactions, which have potential applications in automobile, spacecraft, stationary, industrial and home appliances. Recently there are gaining demand to develop an intermediate temperature fuel cell and available proton conductors at $200{\sim}500^{\circ}C$, which promising operating temperatures range for both material science and energy conversion processes. In this paper, we have reviewed electrochemical properties and current technology of solid state proton conductors. In addition, development of intermediate temperature fuel cell using the perovskite-type solid protonic conductor is also discussed.

• Journal of Hydrogen and New Energy
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• v.19 no.2
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• pp.118-123
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• 2008

For the hydrogen recirculation system of the PEMFC (polymer electrolyte membrane fuel cell), the ejector is useful to improve the efficiency of the fuel cell system. However, conventional ejector does not keep its entrainment ratio good when the various power duties is required by the fuel cell system. In this study, the variable multi-ejector acceptable in the whole duty range required from the fuel cell hybrid mini-bus is developed. Consequently, the performance of the developed ejector is verified by the experiments based on the real operating conditions.

• Journal of Auto-vehicle Safety Association
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• v.13 no.4
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• pp.73-80
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• 2021

Recently, Korea has established a plan for the supply of hydrogen vehicles and is promoting the expansion of the supply. Risk factors for hydrogen vehicles are hydrogen leakage, jet fire, and explosion. Therefore Safety measures are necessary for this hazard. In addition, risks in semi-closed spaces such as tunnels, underground roads, and underground parking lots should be analyzed. In this study, an explosion experiment was conducted on a hydrogen tank used in a hydrogen vehicle to analyze the risk of a hydrogen vehicle explosion accident that may occur in a semi-closed space. As results, the effect on the structure and the human body was analyzed using the overpressure and impulse values for each distance generated during the explosion.