• 무역학회지
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• 제47권1호
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• pp.1-12
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• 2022

This study analyzes FCEV among measures to respond to climate change policies. In particular, it proposes alternatives to solve this problem in the trade industry, which relies on transportation sectors with high greenhouse gas emissions such as exports and imports of goods. Therefore, when FCEV is introduced in the transportation sector, changes in CO2 emissions, a greenhouse gas, and changes in logistics costs for changes in CO2 emissions are set through scenarios to evaluate the impact on product trade, such as imports and exports. As a result, the increase in logistics costs due to carbon dioxide emissions affected the import and export volume of goods, and when FCEV was introduced, the export volume would increase by up to 5.6%, and the import volume by up to 30%. In addition, CO2 emissions decreased to about 60% in 2050. Therefore, the introduction of FCEV in the transportation sector will greatly contribute to increasing sales in the trading industry and will be able to solve environmental problems such as greenhouse gas reduction.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.73.1-73.1
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• 2010

For the successful cold starting of a fuel cell engine, either internal of external heat supply must be made to overcome the formation of ice from water below the freezing point of water. In the present study, switchable vanadium oxide compounds as variable temperature-electrical resistance materials onto the surface of flat metallic bipolar plates have been prepared by a dip-coating technique via an aqueous sol-gel method. Subsequently, the chemical composition and micro-structure of the polycrystalline solid thin films were analyzed by X-ray diffraction, X-ray fluorescence spectroscopy, and field emission scanning electron microscopy. In addition, it was carefully measured electrical resistance hysteresis loop over a temperature range from $-20^{\circ}C$ to $80^{\circ}C$ using the four-point probe method. The experimental results revealed that the thin films was mainly composed of Karelianite $V_2O_3$ which acts as negative temperature coefficient materials. Also, it was found that thermal dissipation rate of the vanadium oxide thin films partially satisfy about 50% saving of the substantial amount of energy required for ice melting at $-20^{\circ}C$. Moreover, electrical resistances of the vanadium-based materials converge on an extremely small value similar to that of pure flat metallic bipolar plates at higher temperature, i.e. $T{\geq}40^{\circ}C$. As a consequence, experimental studies proved that it is possible to apply the variable temperature-electrical resistance material based on vanadium oxides for the cold starting enhancement of a fuel cell vehicle and minimize parasitic power loss and eliminate any necessity for external equipment for heat supply in freezing conditions.

• 대한기계학회논문집A
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• 제35권7호
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• pp.813-819
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• 2011

본 연구에서는 연료전지자동차의 초경량 복합재료 수소 탱크에 대한 수소 충전 특성을 파악하고, 충전 조건에 따른 수소 탱크의 안전성을 확인하기 위해 플라스틱 라이너를 사용하는 Type 4 수소 탱크와 알루미늄 라이너를 사용하는 Type 3 수소 탱크에 대해 수소 충전 시, 수소 탱크 내부의 가스 온도 및 압력 변화, 라이너 및 복합재료 층의 온도 변화 등을 측정하여 그 특성을 고찰하였다. 그 결과 충전 속도가 증가함에 따라 탱크 내부 가스의 온도가 증가하였고, 탱크 내부 가스의 온도 분포가 다르게 나타났다.

• 설비공학논문집
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• 제28권8호
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• pp.325-330
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• 2016

This study was conducted to develop a heating system for a fuel cell-driven electric vehicle. The system consists of a compressor, an expansion device and three heat exchangers. A conventional air source heat exchanger is used as primary heat exchanger of the system, and an additional water source heat exchanger is used as a pre-heater to supply heat to the upstream air of the primary heat exchanger. On the other hand, the third heat exchanger consists of a water-to-refrigerant heat exchanger. The heat source of the pre-heater and the water-refrigerant heat exchanger is the waste heat from the fuel cell's stack. In the experiment, the indoor and the outdoor air temperature were fixed, and the compressor speed, EEV opening and waste heat temperature were varied. The results indicate that the $COP_h$ of the proposed system is 3.01 when the system is operating at a 1,200 rpm compressor speed, 50% EEV opening, and $50^{\circ}C$ waste heat source temperature in air pre-heater operation. However, when the system uses a water-refrigerant heat exchanger, the $COP_h$ increases to up to 9.42 at the same compressor speed and waste heat source temperature with 75% EEV openings.

• 한국터널지하공간학회 논문집
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• 제23권6호
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• pp.439-449
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• 2021

최근 온실가스 저감과 더불어 저탄소배출 정책 등 환경오염에 관심이 증대되고 있다. 이에 따라 탄소배출을 저감할 수 있는 수소전지자동차를 비롯한 친환경 자동차의 보급률이 증가하고 있어 이에 대한 방재 및 안전관련 대책에 요구되고 있는 실정이다. 본 연구에서는 지하주차장의 장소에 국한하여 환기조건에 따라 수소연료자동차의 방출 시 수소의 농도 분포에 대한 위험정도를 수치해석을 통해 분석하였다. 그 결과, 수소탱크가 1개만 방출 될 경우 지하주차장 내 수소의 가연체적비는 최대 8.6%로 나타났으며, 환기가 지속적으로 이루어짐에 따라 연소가능한 수소의 체적비율은 150초 이후 1% 미만으로 감소되는 것으로 분석되어 기계적인 환기가 필수적인 것으로 분석되었다. 수소탱크 3개가 동시방출 또는 단계방출의 경우 최종적인 수소의 가연체적비율은 유사하지만 단계적으로 지연 방출함에 따라 방출 초기 수소의 가연체적비율의 증가폭이 낮은 것으로 나타났으며, 이에 따른 수소탱크 방출 시나리오의 추가적인 연구가 필요한 것으로 예상된다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2010년도 춘계학술대회 논문집
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• pp.48-48
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• 2010

Sound quality and NVH-issues(Noise, Vibration and Harshness) of vehicles has become very important for car manufacturers. It is interpreted as among the most relevant factors regarding perceived product quality, and is important in gaining market advantage. The general sound quality of vehicles was gradually improved over the years. However, today the development cycles in the automotive industry are constantly reduced to meet the customers' demands and to react quickly to market needs. In addition, new drive and fuel concepts, tightened ecological specifications, increase of vehicle classes and increasing diversification(increasing market for niche vehicles), etc. challenge the acoustic engineers trying to develop a pleasant, adequate, harmonious passenger cabin sound. Another aspect concerns the general pressure for reducing emission and fuel consumption, which lead to vehicle weight reductions through material changes also resulting in new noise and vibration conflicts. Furthermore, in the context of alternative powertrains and engine concepts, the new objective is to detect and implement the vehicle sound, tailored to suit the auditory expectations and needs of the target group. New questions must be answered: What are appropriate sounds for hybrid or electric vehicles? How are new vehicle sounds perceived and judged? How can customer-oriented, client-specific target sounds be determined? Which sounds are needed to fulfil the driving task, and so on? Thus, advanced methods and tools are necessary which cope with the increasing complexity of NVH-problems and conflicts and at the same time which cope with the growing expectations regarding the acoustical comfort. Moreover, it is exceedingly important to have already detailed and reliable information about NVH-issues in early design phases to guarantee high quality standards. This requires the use of sophisticated simulation techniques, which allow for the virtual construction and testing of subsystems and/or the whole car in early development stages. The virtual, testing is very important especially with respect to alternative drive concepts(hybrid cars, electric cars, hydrogen fuel cell cars), where complete new NVH-problems and challenges occur which have to be adequately managed right from the beginning. In this context, it is important to mention that the challenge is that all noise contributions from different sources lead to a harmonious, well-balanced overall sound. The optimization of single sources alone does not automatically result in an ideal overall vehicle sound. The paper highlights modern and innovative NVH measurement technologies as well as presents solutions of recent NVH tasks and challenges. Furthermore, future prospects and developments in the field of automotive acoustics are considered and discussed.

• 전력전자학회논문지
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• 제26권6호
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• pp.404-410
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• 2021

This paper proposes a high step-up converter with zero-voltage transition (ZVT) cell for fuel cell electric vehicle. The proposed converter applies a ZVT cell to a dual floating output boost converter (DFOBC) so that not only the main switch but also the ZVT switch can achieve full-range soft switching. The current rating of the ZVT switch is 17% of the main switch. The proposed converter has high reliability in that no timing issue occurs. Therefore, online calculation is not required. The minimum turn-on time of the ZVT switch that guarantees soft switching at all loads and input/output voltage is obtained by analysis. In addition, the proposed DFOBC allows the use of a 650 V device even at 800 V output and has the advantage of being able to boost the voltage by 3.5 times with 0.56 duty. Planar coupled inductor with PCB winding was successfully implemented with the converter operated at 300 kHz. The 25 kW prototype achieves peak efficiency of 99% and power density of 63 kW/L.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.384-387
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• 2005

Fuel cell has been well known as a clean alternative power for vehicles. Recently, an experimental technique has been developed measurement of species and distributions by using gas chromatograph. In this study, cathode channel oxygen distributions as various conditions were investigated using gas chromatograph and cell visualization. And discussed relation between flooding and oxygen concentrations. As a result of experiment, oxygen consumpt ion is affected wi th flooding. Flooding is observed in channel near hydrogen inlet, and oxygen consumption is low at that region.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 추계학술대회
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• pp.17-18
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• 2017

본 논문에서는 수소자동차(Fuel Cell Electric Vehicles: FCEVs)용 고전압 직류 변환장치 (High Voltage DC-DC Converter: HDC)의 소프트 스위칭 셀 최적 설계 방안을 제시한다. 선정된 소프트 스위칭 셀에서 손실 분석을 통해 최적의 공진 네트워크 설계를 제안한다. 제안하는 설계 방안의 타당성은 실험 분석을 통해 검증한다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제37회 추계학술대회논문집
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• pp.683-684
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• 2011

연료전지시스템을 항공기 동력원으로 사용하기 위해서는 요구되는 출력에 필요한 스택성능과 한정된 부피 내 연료전지시스템을 탑재하기 위한 운전장치 구성, 그리고 무게를 최소화하기 위한 부품 및 재료 선정이 필요하다. 스택의 기본성능은 MEA(Membrane electrode assembly)와 기체확산층 구조, 분리판 디자인 및 운전조건 등에 의해 결정된다. 스택의 기본성능은 연료전지시스템을 구성하는 운전장치 구성 및 성능에 의해 달라지기 때문에 어떠한 운전장치를 어떠한 구성으로 설계하는가에 따라서 성능이 변한다고 볼 수 있다. 본 연구에서는 연료전지시스템을 항공기 동력원으로 사용하기 위해서 고려되어야할 스택과 운전장치의 구성이 성능에 미치는 영향과 운전환경(스택 경사, 고도)이 연료전지 스택성능에 미치는 영향에 대해 고찰하였다.