• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2006년도 춘계학술대회 논문집
• /
• pp.549-550
• /
• 2006

Mobile fuel cell is highlighted in these days because mobile fuel cell can contain more energy than existing batteries. Nowadays mobile devices like cellular phone, PMP(portable multi-media player), notebook, and etc. need more energy, But existing batteries like Li-ion or Ni-MH batteries are not going to satisfy such demands. In this paper, mobile fuel cell is developed. Its size is 50*70*8mm and it is made of aluminium plates. The fuel cell type is PEM and the fuel is pure hydrogen and oxygen.

• 한국생산제조학회지
• /
• 제20권2호
• /
• pp.129-132
• /
• 2011

This paper presents small hydrogen regulator for the mobile fuel cell. Mobile fuel cell is generally classified into open-end type and dead-end type. In the open-end type, flow rate of hydrogen is constantly controlled, while pressure of hydrogen is constantly maintained in the dead-end type. Considering the efficiency and stability of the fuel usage, dead-end type is more suitable with mobile fuel cell. Mobile fuel cell operated by dead-end mode requires hydrogen regulator which controls the hydrogen pressure from 0.1bar to 0.5bar within 3% error. In this paper, small hydrogen regulator (volume of 2.6cc) was fabricated by stainless steel. Regulation characteristics was experimentally evaluated.

• 전기화학회지
• /
• 제5권1호
• /
• pp.27-29
• /
• 2002

본 연구는 메탄올과 공기를 이용하여 상온, 상압에서 전기를 발생시키는 휴대폰용 전원공급 장치의 개발에 관한 것이다. 이 장치는 직접 메탄을 연료전지(DMFC)와 Back-up전지가 병렬로 연결되어 있어, 통화시 소요 전력의 최대 $50\%$ DMFC가 공급하고 나머지 부분은 Back-up 전지가 공급한다. 또한 통화 대기시에는 DMFC가 $100\%$ 필요 전력을 공급하고, 잉여 전력으로 Back-up전지를 충전한다. 상기 DMFC는 유효면적이 $9cm^2$인 8개의 단위전지가 직렬로 연결되어 있으며, 휴대폰의 작동 전압 범위인 2.5-3.9V의 전압을 출력한다.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2006년도 춘계학술대회논문집
• /
• pp.858-861
• /
• 2006

In this paper, a study on the noise reduction in a mobile fuel cell system is presented. Among various fuel cell systems around 20W capacities designed for mobile electronic devices, the active direct methanol fuel cell (DMFC) systems have been recently developed. In such systems, the primary noise source is the air pump which provides sufficient air flow ($5{\sim}6$ liter/min) for electrochemical reaction with methanol fuel while the noise contributions from other auxiliary parts are relatively small. Especially, the discrete noise tones generated by the air pump are dominant and those frequency peaks related to the rotor harmonics are needed to be suppressed by a silencer. Therefore. the Herschel/Quinke (HQ) tubes, which use the out-of-phase cancellation of acoustic waves propagating through direct and indirect pathways, are applied to the inlet of the air pump. Performance of noise reduction with HQ silencer is analytically estimated by calculating the transmission. The length and number of thin HQ tubes are optimized to decrease the radiated noise. As a result, the sound pressure level could be successfully reduced by about 10 dB after applying three serially connected HQ tubes.

• 한국막학회:학술대회논문집
• /
• 한국막학회 2004년도 춘계 총회 및 학술발표회
• /
• pp.1-8
• /
• 2004

Ion-conducting polymer electrolyte membranes (PEMs) have recently used in developing fuel cell or solar cell for portable, mobile and residential applications [1]. Polymer electrolyte membrane fuel cell (PEMFC), direct methanol fuel cell (DMFC), alkaline electrolyte fuel cell (AFC) and dye-sensitized solar cell have been employing the ion-conducting PEMs to complete their electrical circuits to produce electricity.(omitted)

• 한국태양에너지학회 논문집
• /
• 제34권4호
• /
• pp.123-129
• /
• 2014

Photovoltaic and fuel cell systems can be used as power source in mobile robots. At this time the photovoltaic system generally generate power in daytime. The starting time of fuel cell is slower than the lithium battery. To compensate for these disadvantages, a battery charge-discharge system is used. Especially the bi-directional converter is used mainly in the charge-discharge method. The controller in a buck converter controls the input voltage of the converter to meet the maximum power point tracking(MPPT) performance. First of all, the simulations of hybrid system for battery charge-discharge system in each step simulated using solar and fuel cell modeling as input source in PSIM. Experiment of the buck and bi-directional converter system is conducted through using photovoltaic/fuel cel simulator(pCube) instead of solar and fuel cell. This hybrid system for battery charge discharge using photovoltaic/fuel cell generates emergency power for the communication system in mobile robot.

• 전기학회논문지P
• /
• 제58권4호
• /
• pp.592-596
• /
• 2009

DAFC(direct alcohol fuel cell) takes the same structure and operational principle with PEMFC(Proton exchange membrane fuel cell). However, DAFC, which uses liquid alcohol instead of hydrogen as fuel, is able to be used as a portable power for small-scaled electronic devices such as MP3, PMP, and mobile phone because alcohol is quite convenient steady-state compound to carry and store it. This paper presents the OCV(open circuit voltage) characteristics of the cases which are alcohol species and different weight rate of ethanol, respectively. The OCV of methanol fuel cell is slightly higher 0.2V than ethanol one, and 8% wt. rate ethanol is rated as the most appropriate fuel for DAFC.

• 설비공학논문집
• /
• 제20권3호
• /
• pp.197-204
• /
• 2008

DMFC(Direct Methanol Fuel Cell) is one of promising candidates for power sources of small mobile IT devices like notebook, cell phone, and so on. Efficient operation of fuel cell system is very important for long-sustained power supply because of limited fuel tank size. It is necessary to investigate operation characteristics of fuel cell stack for optimal control of DMFC system. The generated voltage was modeled according to various operating condition; methanol concentration, stack temperature, and load current. It is inevitable for methanol solution at anode to cross over to cathode through MEA(membrane electrode assembly), which reduces the system efficiency and increases fuel consumption. In this study, optimal operation conditions are proposed by analyzing stack performance model, cross-over phenomenon, and system efficiency.

• 한국에너지공학회:학술대회논문집
• /
• 한국에너지공학회 2004년도 추계 학술발표회 논문집
• /
• pp.133-138
• /
• 2004

Proton exchange membrane fuel cell (PEMFC) is considered as a clean and efficient energy conversion det ice for mobile and stationary applications. Anions all the components of the PEMFC, the interface between the electrolyte ,and electrode catalyst plays an important role in determining tile cell performance since the electrochemical reactions take place at the interface in contact with tile reactant gases. Therefore, to increase the interface area and obtain a high-performance PEMFC, surface of the electrolyte membrane was roughened by Ar$^{+}$ beam bombardment. The results imply that by modifying surface of the electrolyte membrane, platinum loading can be reduced significantly without performance loss. To optimize the surface treatment condition, effects of ion dose density on characteristics of the membrane/electrode interface were examined by measuring the cell performance, impedance spectroscopy, and cyclic voltammograms. Surface of the modified membranes were characterized using scanning electron microscopy and FT-IR.R.

• 한국가스학회지
• /
• 제25권6호
• /
• pp.80-84
• /
• 2021

수소법이 제정됨에 따라 수소용품 4종이 검사대상제품으로 지정되었다. 수소용품의 종류는 수전해설비, 수소추출설비, 고정형 연료전지, 이동형 연료전지이다. 수소용품 검사를 위한 안전기준 제정은 각 수소용품별 위험요소를 정의하였고 위험요소를 예방하기 위한 안전기준을 수소용품 기준에 규정하였다. 각 수소용품 별 주요 안전기준은 수전해설비는 수소품질 및 안전제어, 수소추출설비는 독성물질 배출 방지 및 일산화탄소 배출 방지, 고정형 연료전지는 배출가스 규제 및 버너 안전성능, 이동형 연료전지는 진동안전성이 안전기준에 규정하여 안전성을 강화하였다.