• Transactions of the Korean hydrogen and new energy society
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• v.34 no.6
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• pp.682-688
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• 2023

In this paper, analyzes the type of failure and its effect on the hydrogen fueling nozzle used in hydrogen station. Failure of hydrogen fueling nozzle was analyzed using a qualitative risk assessment method, failure mode and effect analysis. The failure data of hydrogen fueling nozzles installed in domestic hydrogen stations are collected, and the failure types are classified, checked the main components causing the failure. Criticality analysis was derived based on frequency and severity depending on the failure mode performed. A quality function is developed by a performance test evaluation item of the hydrogen fueling nozzle, and the priority order of design characteristics is selected. Through the analysis results, the elements to improve the main components for enhancing the quality and maintenance of the hydrogen fueling nozzle were confirmed.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.5
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• pp.447-455
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• 2023

SAE J2601, hydrogen fueling protocols, proposes two charging methods. The first is the table-based fueling protocol, and the second is the MC formula-based fueling protocol. Among them, MC formula-based fueling protocol calculates and supplies the target pressure and pressure ramp rate (PRR) using the pre-cooling temperature of the hydrogen and the physical parameters of the tank in the vehicle. The coefficient of the MC formula for deriving MC varies depending on the physical parameters of the tank in the vehicle. However, most studies use the MC coefficient derived from SAE J2601 as it is, despite the difference in the physical parameters of the tank applied to the study and the tank used to derive the MC coefficient from SAE J2601. In this study, the MC coefficient was derived by applying the hydrogen tank currently used, and the difference with the fueling performance using the MC coefficient proposed in SAE J2601 was verified. In addition, the difference was confirmed by comparing and analyzing the fueling performance of the table-based method currently used in hydrogen fueling stations and the MC formula-based method using MC coefficient derived in this study.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.21-24
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• 2006

수소의 소규모 분산 생산 기술은 본격 적 인 수소 인프라가 도입되기 전에 연료전지 자동차의 수소 충전용이나 분산 발전형 연료전지의 수소 공급을 위해 필요하다. 생산 용량은 수소 기준으로 $20{\sim}100 Nm^3/hr$ 정도로 현재로선 천연가스의 수증기 개 질법이 가장 경제적인 공정으로 알려져 있다. 소규모 생산에 따른 열효율 저하를 줄이 기 위해 단위 공정들이 통합된 컴팩트 개질 시스템의 개발이 필요하다. 연료전지 자동차용 수소 인프라 조기 구축을 위하여 수소충전소 구축과 국산화 천연가스 수증기 개질기 개발을 병행하여 진행하였다. 수소 충전소 구축 부분은 충전소 부지 확보, 건물 건축, 각종 유틸리 티 설치의 토목 부분과 천연가스 개질형 수소 제조 유닛 설치, 수소 압축, 저장, 디스펜싱 시스템 설치를 포함하고 있으며 고압 설비에 대한 인허가 대응 및 안전대책 작업도 진행하였다. 구축된 수소충전소는 향후 연료전지 자동차 연계 실증 프로그램에 활용할 수 있다. 국산화 핵심 기술 개발을 위하여 열 및 시스템 통합 설계에 의 해 천연가스 수증기 개질기를 제작하고 내부 열교환 구조에 따른 개질기의 성능을 평가하였다. 개발된 개질기는 개질온도 $720^{\circ}C$, 수증기 대 카본 비 2.7의 운전조건에서 $23Nm^3/h$ 이상의 수소 생산이 가능하였으며 73% 이상의 개질 효율을 나타내었다. 개발된 천연가스 수증기 개질기는 향후 수소 정제용 PSA(Pressure Swing Adsorption) 시스템과 연계하여 수소충전소 국산화 엔지니어링 설계 패키지 개발의 핵심 기 술로 사용할 계획이다.시간 정도 운전한 후 시스템을 정지하였다 메탄 전환율과 일산화 탄소 농도, 열효율을 모니터링 하고 있으며, 현재까지 초기 성능을 그대로 유지하고 있다. 앞으로 일일시동-정지 운전 시험을 지속하면서 초기 시동 특성 및 부하 변동에 따른 응답 특성 개선, 그리고 연료전지와의 연계 운전을 실시할 예정이다 한다. 단위 전지 운전 온도 $130^{\circ}C$, 상대습도 37%의 운전 조건에서도 상당히 우수한 전지 성능을 보임에 따라 고온/저가습 조건에서 상용 Nafion 112 막보다 우수한 막 특성을 나타냄을 확인하였다.소/배후방사능비는 각각 $2.18{\pm}0.03,\;2.56{\pm}0.11,\;3.08{\pm}0.18,\;3.77{\pm}0.17,\;4.70{\pm}0.45$ 그리고 $5.59{\pm}0.40$이었고, $^{67}Ga$-citrate의 경우 2시간, 24시간, 48시간에 $3.06{\pm}0.84,\;4.12{\pm}0.54\;4.55{\pm}0.74 $이었다. 결론 : Transferrin에 $^{99m}Tc$을 이용한 방사성표지가 성공적으로 이루어졌고, $^{99m}Tc$-transferrin의 표지효율은 8시간까지 95% 이상의 안정된 방사성표지효율을 보였다. $^{99m}Tc$-transferrin을 이용한 감염영상을 성공적으로 얻을 수 있었으며, $^{67}Ga$-citrate 영상과 비교하여 더 빠른 시간 안에 우수한 영상을 얻을 수 있었다. 그러므로 $^{

• JOURNAL OF ELECTRICAL WORLD
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• s.337
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• pp.34-39
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• 2005

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.6
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• pp.684-691
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• 2022

Hydrogen fuel cell electric vehicles are typically refueled at a wide range of temperatures (-40℃ to 85℃) in the hydrogen refueling station in accordance with the worldwide accepted standard. Currently, there is no traceable method by which to verify and calibrate the hydrogen flowmeters to be used at hydrogen refueling stations except for a water calibration process as a conventional method. KRISS hydrogen field test standard based on the gravimetric principle was developed to verify the measurement accuracy of the mass flowmeter to be used at hydrogen refueling stations for the first time in Korea.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.66-73
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• 2020

In the hydrogen compression cycle, which is currently being developed, hydrogen is compressed to a very high pressure using a compressor, and then stored and used in a high-pressure vessel. This shows that an increase in the temperature of hydrogen in the vessel due to a pressure rise during the filling process and the pressure fatigue due to the repeated cycle may cause problems in the reliability of the vessel. In this paper, for the entire processes in a 50 MPa hydrogen compression system, theoretical and numerical methods were conducted to analyze the following: the temperature increase of hydrogen in the vessel and the time required to reach thermal equilibrium with the surroundings, the change in temperature of hydrogen passing through the pressure reducing valve, and the required capacity of the heat exchanger for cooling the vessel. The results will be useful for the design and construction of hydrogen compression systems, such as hydrogen charging stations.

• Explosives and Blasting
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• v.40 no.3
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• pp.19-32
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• 2022

Hydrogen is a fuel having the highest energy compared with other common fuels. This means hydrogen is a clean energy source for the future. However, using hydrogen as a fuel has implication regarding carrier and storage issues, as hydrogen is highly inflammable and unstable gas susceptible to explosion. Explosions resulting from hydrogen-air mixtures have already been encountered and well documented in research experiments. However, there are still large gaps in this research field as the use of numerical tools and field experiments are required to fully understand the safety measures necessary to prevent hydrogen explosions. The purpose of this present study is to develop and simulate 3D numerical modelling of an existing hydrogen gas station in Jeonju by using handheld LiDAR and Ansys AUTODYN, as well as the processing of point cloud scans and use of cloud dataset to develop FEM 3D meshed model for the numerical simulation to predict peak-over pressures. The results show that the Lidar scanning technique combined with the ANSYS AUTODYN can help to determine the safety distance and as well as construct, simulate and predict the peak over-pressures for hydrogen refueling station explosions.

• Transactions of the Korean hydrogen and new energy society
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• v.32 no.5
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• pp.356-364
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• 2021

During the hydrogen fueling process, hydrogen temperature inside the compressed tank were limited below 85℃ due to the allowable pressure of tank material. The chiller system to cool compressed hydrogen used R407C, greenhouse gas with a high global warming potential (GWP), as a refrigerant. To reduce greehouse gas emission, it should be replaced by refrigerant with a low GWP. This study proposes a chiller system for fueling hydrogen with R290, consisted in propane, by applying the C3 pre-cooled system use d in the LNG liquefaction process. The proposed system consisted of hydrogen compression and cooling sections and optimized the operating pressure through exergy analysis. It was also compared to the exergy efficiency with the existing system at the optimal operating pressure. The result showed that the optimal operating pressure is 700 kPa in 2-stage, 840 kPa/490 kPa in 3-stage, and the exergy efficiency increased by 17%.

• Transactions of the Korean hydrogen and new energy society
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• v.18 no.3
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• pp.342-347
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• 2007

The research on production and application of hydrogen as an alternative energy in the future is being carried out actively. It hydrogen storage is necessary in order that user use hydrogen economically without much difficulty. Among the ways of hydrogen storage the method which is compressed hydrogen gas by high pressure is easier for application than other methods. In this study, we have been calculated gas with changing pressure and temperature variation of container wall through applied to mass and energy balance equation when compressing hydrogen by high pressure, and also to Beattie-Bridgeman equation of state for the kinetic of hydrogen. We will apply above date as a preliminary for design of hydrogen storage tank.

• 한국전기화학회:학술대회논문집
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• 2004.06a
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• pp.141-148
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• 2004

지구의 환경보존과 에너지원의 효율적인 이용을 위하여 고효율의 환경친화적 청정에너지 기술개발을 활발이 진행중에 있으며, 이중 수소를 이용한 연료전지차 개발이 최근 가장 각광을 받고 있다. 연료전지차 실용화를 위해서는 여러 가지 기술적으로 해결해야 과제가 많으나, 그 중에서도 연료로 사용하고 있는 수소의 안전적인 저장 문제가 중요하다고 하겠다. 수소를 저장하는 방법은 여러 가지 있으나, 현재 기술로 이용 가능한 것은 압축저장 방식이다. 현재 소개되고 있는 연료전지차 대부분에는 350 bar 압축수소저장용기가 탑재되어 $120\~300km$까지 주행이 가능하다. 이는 소비자 입장에서 수소충전을 자주해야 하는 불편사항이다. 이를 보완하기 위해서 초고압 (700 bar) 수소저장시스템과 저압이면서 수소를 더 많이 저장할 수 있는 신 수소저장물질 개발을 각 연구기관에서 활발이 연구중에 있다. 국내에서도 최근에 연료전지차의 관심이 높아지면서 연료전지차량용 부품 개발을 정부과제로 연구중이거나 예정이다. 수소저장분야도 21세기 프론티어사업을 통하여 산.학.연 합동으로 연구를 활발이 진행중에 있다.