• Corrosion Science and Technology
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• 제21권6호
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• pp.503-513
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• 2022

As part of eco-friendly policies, interest in hydrogen vehicles is growing in the automotive industry to reduce carbon emissions. In particular, it is necessary to investigate the application of aluminum alloy for light weight hydrogen valves among hydrogen supply systems to improve the fuel efficiency of hydrogen vehicles. In this research, we investigated mechanical characteristics of aluminum alloys after hydrogen embrittlement considering the operating environment of hydrogen valves. In this investigation, experiments were conducted with strain rate, applied voltage, and hydrogen embrittlement time as variables that could affect hydrogen embrittlement. As a result, a brittle behavior was depicted when the strain rate was increased. A strain rate of 0.05 mm/min was selected for hydrogen embrittlement research because it had the greatest effect on fracture time. In addition, when the applied voltage and hydrogen embrittlement time were 5 V and 96 hours, respectively, mechanical characteristics presented dramatic decreases due to hydrogen embrittlement.

• 한국자동차공학회논문집
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• 제15권3호
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• pp.174-182
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• 2007

Fuel reforming technology for the fuel cell vehicles could be applied to internal combustion engine for the reduction of engine out emissions. Since syngas which is reformed from fossil fuel has hydrogen as a major component, it has abilities to enhance the combustion characteristics with wide flammability and high speed flame propagation. In this study, syngas was added to a gasoline engine to improve combustion stability and exhaust emissions of idle state. Syngas fraction is varied to 0%, 50%, 100% with various ignition timing and excess air ratio. Combustion stability, exhaust emissions, fuel consumption and exhaust gas temperature were measured to investigate the effects of syngas addition on idle performance. Results showed that syngas has ability to widely extend lean operation limit and ignition retard range with dramatical reduction of engine out emissions.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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• pp.451-454
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• 2003

In this paper, the research trend and the sate-of-the-art of low cost motor drives are introduced with the recently increasing interest In various industrial applications, such as home appliance, hybrid electric vehicles, wind power systems, fuel cell systems, and etc. Based on this presented work, it is highly expected the power electronics technologies, which are accumulated through the last 20 years, can be effectively applied to actual application fields.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2003년도 춘계 학술발표회 논문집
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• pp.211-232
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• 2003

연료전지 개발 필요성; "One of the most important technologies for the early 21st century" - Bill Clinton, "Not only to encourage research and development, but to provide tax credits to enhance the marketplace of hybrid and fuel-cell vehicles" - Bush. 연료전지 장점 - 에너지 변환 고효율(70%), 무/저공해 발전, 높은 에너지 저장력 (고용량), 시장환경 - 석유 자원 유한, 환경오염에 따른 무공해 에너지원 필요, Portable Device의 장시간 사용 Needs.(중략)

• 대한기계학회논문집B
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• 제35권6호
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• pp.585-592
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• 2011

냉시동 성능 개선은 연료전지 차량의 고분자 전해질 연료전지 발전 모듈 및 시스템의 내구성과 신뢰성 향상의 측면에서 매우 중요하다. 이에 본 연구에서는 영하의 기후에서 연료전지 차량의 초기 구동 시금속 분리판 표면에 형성된 바나듐 산화물 박막의 자기 발열 특성을 이용하여 신속한 온도 상승 구현이 가능한 냉시동 향상 기술을 제안하고, 실험적 방법을 통해 그 적용 가능성을 검증하였다. 졸-겔 침지 법에 의해 제조된 바나듐 산화물 박막의 특성 평가를 위해 X 선 회절, 광전자 분광, 전자 주사 현미경을 이용한 화합물 조성 및 미세구조 분석, 4-탐침법을 이용한 $-20{\sim}80^{\circ}C$의 온도 구간에서의 온도-저항 이력 특성 분석을 각각 수행하였다. 본 실험 결과, 냉시동 조건에서 박막의 자기 발열량은 연료전지 내부의 생성 수 결빙 방지에 필요한 열 에너지를 모두 충족시킬 수 있음을 확인하였다.

• 한국가스학회지
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• 제17권6호
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• pp.46-51
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• 2013

복합재 압력용기는 높은 비강성과 비강도 그리고 내피로성으로 수소연료전지자동차와 천연가스자동차에 사용된다. 이음매가 없는 일체형 라이너를 갖는 복합재 압력용기는 고강도 탄소섬유와 에폭시 레진으로 라이너 전체를 감싼다. 본 연구에서는 구조적으로 취약한 너클 부위와 압축잔류응력을 고려하여 필라멘트 와인딩 패턴과 자긴압력 설계 기법을 제시하였다. 복합재 압력용기 시제품에 대한 압력반복시험을 통해 제안된 방법을 검증한다.

• Journal of Power Electronics
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• 제9권1호
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• pp.68-73
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• 2009

Automotive inverters may require current sensors for motor torque control, especially, in applications of hybrid electric vehicles or fuel cell vehicles. In this paper, to achieve a compact, integrated and low cost current sensor, a hall current sensor without magnetic core is introduced for integrating an automotive inverter. The compactness of the current sensor is possible by using integrated magnetic concentrators based on the Hall effect. Magnetic fields caused by three-phase currents are analyzed and a magnetic shield design is proposed for decoupling the cross-coupled field. It offers galvanic isolation, wide bandwidth (>100kHz), and accuracy(< 1%). Using 2D FEM analysis, its performance is demonstrated with design parameters at a U-shaped magnetic shield. The proposed coreless current sensor is tested with rated current to validate the linearity and accuracy.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2006년도 전력전자학술대회 논문집
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• pp.225-227
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• 2006

The U.S. Department of Energy's National Renewable Energy Laboratory (NREL) first developed ADVISOR in 1994. Between 1998 and 2003 it was downloaded by more than 7,000 individuals, corporations, and universities world-wide. In early 2003 NREL initiated the commercialisation of ADVISOR through a public solicitation. AVL responded and was awarded the exclusive rights to license and distribute ADVISOR world-wide. AVL is committed to continuously enhance ADVISOR's capabilities. Provides rapid analysis of the performance and fuel economy of conventional and advanced, light and heavy-duty vehicle models as well as hybrid electric and fuel cell vehicle models. ADVISOR Simulates the Following Vehicle Characteristics. - Optimal drivetrain component sizes that provide the best fuel economy Vehicle's ablility to follow the speed trace - Amount of fuel and/or electric energy required by various vehicle concepts - Peak power and efficiency achieved by the drivetrain components - Torque and speed distribution of the engine - Average efficiency of the transmission - Gradeability of vehicles at various velocities

• 한국수소및신에너지학회논문집
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• 제12권4호
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• pp.277-285
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• 2001

본 논문은 연료전지 자동차용 10kWe급 정제일체형 메탄올개질기에 대한 연구결과이다. 이 개질기에서는 메탄올이 수증기와 반응하켜 수소를 포함한 혼합가스로 개질되고, 그 혼합가스는 다시 Palladium 합금막을 통하여 순수한 수소로 분리된다. 정제되고 남은 폐 가스중 가연성분들은 wire-mesh 형태의 연소촉매상에서 연소되어 개질반응에 필요한 열을 직접 공급함으로써 높은 메탄올 전환율, 고품질의 수소생산, 그리고 높은 시스템 열효율을 가능하게 한다. 동시에 이러한 개질, 분리 및 연소반응이 하나의 반응기에서 일어나 전체 시스템이 소형화될 수 있으며 운전이 용이한 장점도 있다. 본 연구팀에서 개발한 10kWe급 시스템은 운전연구를 통하여 수소생산량은 $8.2Nm^3/hr$ (10kWe급), 수소순도 99.999% 이상, CO 농도 5 ppm 미만, 총합열효율 81%, 초기기동 소요시간 20분, 부하변동웅답 1 분 이내를 달성했으며, 장처의 크기와 무게는 각각 16 L, 25 kg 이다.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2002년도 춘계학술강연 및 발표대회
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• pp.7-7
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• 2002

Recently social demand to achieve low fuel consumption and clean emission requires the development of new generation vehicle beyond the conventional vehicle concept. In this point, new generation vehicle is newly designed as electric vehicle, hybrid electric vehicle, fuel cell electric vehicle or 3 liter car etc. In order to develop new generation vehicle, it is very important to develop new materials and process technologies now. In this paper these new technologies are presented focusing on weight reduction specially. Steel body can be achieved 20-25% weight reduction by adoption of high strength steel and new process technologies, i.e tailored blank and hydroforming. Aluminium body can be achieved 40-50% weigt down by use of all aluminium monocoque body or aluminium space frame with aluminium panel. Plasitic composite body can be achieved 30% weight reduction comparing with conventional steel body.