• 한국가스학회지
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• 제24권5호
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• pp.65-73
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• 2020

본 연구에서는 재생에너지원의 에너지저장기술(Power to gas, P2G)로써 활용되는 수전해기의 가동률 향상과 산소 이용 극대화를 통해 경제성을 확보하기 위해서 수전해기에서 배출되는 산소를 바이오매스 가스화 공정에 공급하여 추가적인 수소 생산을 통해 수소 원가를 감소시키고, 재생에너지원의 출력 감소 시 수전해기를 바이오매스 가스화 공정의 산소 제조/공급 장치로 활용하는 공정을 제안하고, 이에 대한 정량적인 효율 분석과 경제성 분석을 수행하였다.

• 한국수소및신에너지학회논문집
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• 제18권4호
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• pp.413-421
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• 2007

In this paper, the performance characteristics of heat pump system using a new refrigerant subcooling system designed for the study, are introduced. The new heat pump system have the ice storage tank at the outlet of condenser. The experimental apparatus is a well-instrumented water/water heat pump which consisted of working fluid loop, coolant loop, and ice storage tank. The experiment parameters of subcooling ranged as the evaporating temperature from $-5^{\circ}C$ to $8^{\circ}C$, the condensing temperature from $30^{\circ}C$ to $35^{\circ}C$. The test of the ice storage was carried out at evaporating temperature of $-10^{\circ}C$ and the ice storage mode is Ice-On-Coil type. The working fluid was R-22 and the storage materials were city-water. The test results obtained were as follows; The refrigerant mass flow rate and compressor shaft power were unchanged by the degrees of subcooling, that is, they were independent of degrees of subcooling. The cooling capacity of the new heat pump system increase as the evaporating temperature and subcooling degrees increase and is higher by $25{\sim}30%$, compared to the normal heat pump system. The COP of the new heat pump system increases as the degrees of subcooling and evaporating temperature increase and is higher by 28% than that of the normal heat pump system.

• 한국추진공학회지
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• 제13권3호
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• pp.58-63
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• 2009

세계적으로 강화되는 오염물질 배출규제와 유가의 급등은 미래 수송수단의 변화를 가져올 것으로 예상된다. 새로운 대체에너지가 나타나기 까지는 화석연료를 대체할 에너지원으로 수소가 가장 유력하다. 가까운 미래의 항공기는 수소 가스터빈엔진이나 연료전지와 같은 동력장치를 사용할 것으로 과학자들은 예측하고 있다. 향후 연료전지 동력 항공기가 실현되기 위해서는 동력밀도가 높은 연료전지, 고압의 기체 또는 액체상태의 수소연료저장 장치, 그리고 경량의 고효율 전기모터가 개발되어야 한다.

• 한국수소및신에너지학회논문집
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• 제28권5호
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• pp.531-535
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• 2017

The performance of all-vanadium redox flow battery (VRFB) was tested with an increase of the current density. APS membrane (anion exchange membrane) and GF050CH (cabon felt) were used as a separator and electrode, respectively. An average energy efficiency of the VRFB was 79.5%, 68.1%, and 62.8% for the current density of $60mA/cm^2$, $120mA/cm^2$, and $160mA/cm^2$, respectively. It was confirmed that VRFB can be used as a energy storage system at the higher current density even if the energy efficiency was deceased about 21%.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.13-19
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• 2007

To find out the optimum design of hydrogen storage and supply tank using Metal Hydride (briefly MH) and to make clear the performance characteristics under various conditions are our research purpose. In order to use the low-temperature exhaust heat, $LaNi_{4.7}Al_{0.3}$ which operates under the low pressure of 1 MPa is chosen, and we measure the basic properties, namely density, specific heat, PCT(Pressure-Concentration-Temperature) characteristics, and effective thermal conductivity. Then, a numerical calculation model of hydrogen storage using MH alloy is suggested and this thermal diffusion equation of model is solved by the backward difference method. This calculation results are compared with the experimental results of the systems which installed 1kg MH alloy and, it is found out that our calculation model can well predict the experimental results. By the experimental using MH alloy, it is recognized that the hydrogen flow rate can control by the step adjustment of brine temperature.

• 대한화학회지
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• 제59권5호
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• pp.429-433
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• 2015

The binding ability and hydrogen storage capacity of nitrogen doped carbon nanotube with divacancy (4NDCN_xNT) that is decorated with transition metals was investigated based on density functional theory calculations. Results indicate that scandium shows an ideal reversible hydrogen binding capability with promising system-weight efficiency compared with other transition metals when functionalized with 4ND-CN_xNT. The (Sc/4ND)₁₀-CN_xNT can store up to 50H₂ molecules, corresponding to a maximum gravimetric density of 5.8 wt%. Detailed structural stability and electronic properties were reported as hydrogen molecules were absorbed. It takes about 0.16 eV/H₂ to add one H₂ molecule, which assures reversible storage of H₂ molecules under ambient conditions.

• 전기학회논문지
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• 제63권1호
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• pp.184-190
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• 2014

Fuel cell power system, unlike conventional energy sources, converts chemical energy into electrical energy through electrochemical reaction of hydrogen and oxygen. In recent years, railway field as well as mobile fuel cell power system is being studying actively with development of hydrogen storage technologies. This paper presents the feasibility study on small-scale prototype electric railway vehicle application using fuel cell generation system. it is confirmed that proposed fuelcell-battery hybrid system shows good response characteristic about speed and torque based on design of parameter on system. Also as results of response for proposed system modeling, it show that powering mode and braking mode of system is controlled by switching devices of converters.

• 한국수소및신에너지학회논문집
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• 제32권4호
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• pp.263-270
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• 2021

In this study, we proposed the necessity of reusing the battery industry after domestic use, preparing legal arrangements by step for recycling, clarifying responsible materials by processing stage, and establishing infrastructure and screening diagnostic rating system. The purpose of this study is to establish a life cycle integrated management system for electric vehicle batteries and to find suitable ways for improving the lifespan of electric vehicle batteries, reuse, and recycling in stages to avoid other environmental pollution problems due to batteries after using electric vehicles used to reduce environmental pollution due to climate change.

• 한국수소및신에너지학회논문집
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• 제30권4호
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• pp.347-355
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• 2019

As a solution to the growing concern on the global warming, researches are being actively carried out to apply carbon dioxide capture and storage technology to power generation systems. In this study, the integrated gasification combined cycle (IGCC) adopting oxy-combustion carbon capture was modeled and the effect of replacing the conventional air separation unit (ASU) with the ion transport membrane (ITM) on the net system efficiency was analyzed. The ITM-based system was predicted to consume less net auxiliary power owing to an additional nitrogen expander. Even with a regular pressure ratio which is 21, the ITM-based system would provide a higher net efficiency than the optimized ASU-based system which should be designed with a very high pressure ratio around 90. The optimal net efficiency of the ITM-based system is more than 3% higher than that of the ASU-based system. The influence of the operating pressure and temperature of the ITM on system efficiency was predicted to be marginal.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.463-469
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• 2012

Solar thermochemical syngas and hydrogen production process bv redox system of metal oxide was performed under direct irradiation of the metal oxide on the SiC ceramic foam device using solar simulator. $CeO_2/ZrO_2$ nanotube has been synthesized by anodic oxidation method. Syngas and hydrogen production process is one of the promising chemical pathway for storage and transportation of solar heat by converting solar energy to chemical energy. The produced syngas had the $H_2/CO$ ratio of 2, which was suitable for methanol synthesis or Fischer-Tropsch synthesis process. After ten cycles of redox reaction, $CeO_2$ was analyzed using XRD pattern and SEM image in order to characterize the physical and chemical change of metal oxide at the high temperature.