• 한국수소및신에너지학회논문집
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• 제25권3호
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• pp.255-263
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• 2014

This paper deals with a construction plan of hydrogen fueling stations on express highways using geographic information system. We analyzed the existing hydrogen fueling stations and production facilities to construct the hydrogen supply system to satisfy the hydrogen demands. Also, we suggested the necessary number and locations of hydrogen fueling stations on express highways for operating fuel cell vehicles. As a result, we need to construct at least 6 hydrogen stations on express highways in 2020 and 14 hydrogen stations in 2025. In 2030, when fuel cell vehicles are expected to spread over the whole nation, 114 hydrogen stations are needed to construct on express highways. This study mainly utilized the information of distances between hydrogen production facilities and fueling stations. However, we need to analyze the other factors such as traffic and income data. Also, it is necessary to make a suitable construction plan of hydrogen fueling stations that should be constructed on each district using geographic information system.

• 한국수소및신에너지학회논문집
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• 제34권5호
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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.

• 드라이브 ㆍ 컨트롤
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• 제19권2호
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• pp.36-44
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• 2022

Hydrogen energy as an alternative source of energy has been receiving tremendous support around the world, and research is being actively conducted accordingly. However, most of the studies focus on hydrogen storage tanks and only are few studies on interpreting the hydrogen filling system itself. In this study, with reference to SAE J2601, a hydrogen fueling protocol, a simulation model was developed that can confirm the behavior of the vehicle's internal tank during hydrogen fueling. With respect to factors such as fuel supply temperature, ambient temperature, and pressure increase rate, the developed model can check the change of temperature and pressure in the tank and the state of hydrogen charging during hydrogen fueling. The validity of the developed simulation model was confirmed by comparing the simulation results with the experimental results presented in SAE J2601.

• 한국진공학회지
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• 제16권6호
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• pp.489-495
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• 2007

KSTAR 토카막은 현재 주장치 조립을 완료하고 "최초 플라즈마" 발생과 시운전을 준비하고 있다. 이를 위해 설치되어 있는 연료주입계는 배기 덕트 반대 쪽 한 곳만 주입구로 사용하기 때문에 균일하고 신속한 입자공급이 어렵다. 시운전이 끝나고 기본운전 단계가 되면 단순한 플라즈마 생성이 아니라 일정한 고밀도 토카막플라즈마 상태를 일정시간 고르게 유지해야 하므로 공간적으로 균일한 입자공급과 플라즈마 밀도 변화에 따른 신속한 제어가 가능한 연료공급계로 개선되어야 한다. 이런 개선점을 찾는 작업의 일환으로 우선 D-형 진공용기 및 플라즈마 컬럼을 사각단면 토러스로 묘사하는 모델을 만들고 연료공급 위치와 플라즈마의 전리율 및 배기확률에 따라 공간적인 입자분포가 어떻게 바뀌는지 몬테카를로 계산을 통해 분석했다.

• 한국수소및신에너지학회논문집
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• 제34권6호
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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.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.331-336
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• 2001

Theoretical approach was taken to the whole CNG refueling process. In particular, this study was focused on the prediction of flow rate at any given piping configuration of CNG system, in order that a simulation program for the CNG refueling system should be developed. The simulation result of refueling process was compared with experimental result obtained from various kinds of fueling configuration. The simulation results showed a satisfactory agreement within 10% errors in fueling time, fueling amount, and residual pressure. The developed program would be used a good engineering tools for estimating fueling performance for a any given CNG station.

• 한국수소및신에너지학회논문집
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• 제32권5호
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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%.

• 대한교통학회지
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• 제27권3호
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• pp.103-109
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• 2009

항공교통시스템에서 핵심적 역할을 하는 항공사의 운영비 중 유류비용은 가장 큰부분을 차지한다. 따라서 많은 항공사들은 유류비 절감을 위한 많은 노력을 기울이고 있는 실정이다. 이 중 체계적인 항공기 급유계획 전략은 많은 비용절감 효과로 인하여 근래에 많은 주목을 받고 있다. 항공기 급유계획은 항공유의 급유비용이 각 운항공항 별로 상이할 때, 총 유류비를 최소화할 수 있도록 각 항공기의 운항공항에서 최적 급유량을 도출하는 계획이다. 본 연구에서는 항공기 급유계획에 관한 수리모형을 제시한다. 제시된 모형은 각 운항공항의 급유비용과 항공기 경로정보가 알려져 있을 때 각 운항공항에서 총비용을 최소로하는 정확한 급유량을 계산하는 최적화 모형이다. 실험결과, 제안된 모형은 직관적 형태의 발견적 기법보다 효과적인 비용절감이 이루어짐을 확인하였고, 향후 항공사를 비롯한 대형 운송시스템에서 유류관리 전략으로 중요한 역할을 할 것이라 기대된다.

• 한국재난정보학회 논문집
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• 제18권3호
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• pp.520-531
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• 2022

연구목적: 본 연구는 수소충전소의 위험성 평가를 바탕으로, 운영주의 주요 관심 사항인 수익성과 경영 위험성을 고찰함으로써 경영안전성 강화를 위한 방안을 찾고자 한다. 연구방법: 위험성 평가를 수소충전소의 설치단계부터 시간의 흐름에 따라 '수용 가능한 위험성'과 '허용 가능한 위험성'으로 구분하여 기존의 연구결과와 비교, 분석하였다. 연구결과: 수소충전소 설치단계에 실행하는 위험성 평가는 현재 기존의 연구가 적절하게 적용되고 있었다. 그러나 운영단계에서 발생 가능한 위험을 찾을 수 있었다. 즉 경영위험성에 대한 평가도 필요함을 도출하였다. 그리고 이를 통해 수소충전소의 안전성이 강화됨을 확인했다. 결론: 수소충전소 설치단계에 선행되는 위험성평가는 '수용 가능한 위험성' 평가로 모두 유의미한 결과가 도출되어 적절하게 활용되고 있다. 그러나 운영주는 운영단계에서 발생 가능한 위험, 즉 '허용 가능한 위험성' 평가와 대응방안 마련이 필요하다. 따라서 보다 안전한 수소충전소 구축과 운영을 위하여 경영위험성 평가 항목 추가를 제안한다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.39-39
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• 1999

The KSTAR (Korea Superconducting Tokamak Advanced Research) tokamak is a nuclear fusion experimental device for a long pulse/steady-state plasma operation, adopting fully superconducting magnets. In accordance with completion of the basic design of the torus vacuum vessel and the enclosing cryostat, the vacuum pumping and gas fueling basic design has been developed to fulfil the physics requirements. The ultra-high vacuum pumping and sophisticated gas fueling system of the machine is essential to achieve such roles for optimized plasma performance and operation. Recently the vacuum exhaust system using dedicated pumping ports for the vacuum vessel and cryostat has been modified to meet more reliable and successful performance of the KSTAR[Fig. 1].In order to achieve the required base pressure of 5 x 10-9 torr, the total impurity load to the vessel internal is limited to ~5 x 10-5 torr-1/x, while the cryostat base pressure is kept as ~5 x 105 torr to mitigate the thermal load applied to the superconducting magnets. Each KSTAR fueling system will be separately capable of fueling gas at a rate of 50 torr-1/x, consistent with the given pumping throughput. In order to initiate a plasma discharge in KSTAR, the vacuum vessel is filled to a gas pressure of few 10-6 to few 10-4 torr, and additional gas injection is required to maintain and increase the plasma density during the course of the discharge period.