• 한국태양광발전학회지
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• 제7권1호
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• pp.17-26
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• 2021

Cu(In,Ga)Se₂(CIGS) 태양전지 연구개발은 1970년대부터 지속적으로 발전하여 유리 및 플렉서블 기판에서 모두 20% 이상의 고효율을 달성하였으며, 상용화도 성공적으로 이루었다. 최근 태양전지의 초고효율화를 위한 방안으로 태양전지를 적층하는 다중접합 태양전지 특히 제조원가를 고려한 탠덤 구조에 대한 연구가 상당히 주목을 받고 있다. 이는 페로브스카이트 태양전지를 상부셀로 적용하였을 때, 29.5%의 초고효율이 보고되었기 때문이다. 이런 추세로 보면 태양전지의 탠덤 구조는 초고효율화 달성에 필연적으로 사용될 것으로 생각된다. 하지만 초고효율화와 더불어 BIPV, VIPV, 모바일소자 등 심미성, 경량성, 유연성을 갖춘 다기능성 태양전지에 대한 요구까지 충족시키기 위해서는 궁극적으로 유연한 하부셀이 사용되어야 한다. 이런 점들을 고려하였을 때, 초고효율 유연 탠덤 태양전지의 하부셀로 유연 CIGS 박막 태양전지가 적합한 선택이 될 것으로 판단된다. 따라서 본 글에서는 CIGS 박막 태양전지를 기반으로 하는 탠덤 태양전지의 연구개발 현황에 대해서 살펴보고 향후 유연 탠덤 태양전지의 전망에 대해서도 기술하고자 한다.

• 한국태양광발전학회지
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• 제7권2호
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• pp.16-21
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• 2021

• E2M - 전기 전자와 첨단 소재
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• 제34권6호
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• pp.32-41
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• 2021

• 물과 미래
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• 제52권3호
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• pp.6-9
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• 2019

• 전력전자학회지
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• 제26권2호
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• pp.43-47
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• 2021

• 한국수소및신에너지학회논문집
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• 제30권4호
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• pp.330-337
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• 2019

Effects of cyclone and freeboard geometry on solid entrainment loss were investigated with two different types of cyclones and bubbling beds in a gas-solid fluidized bed system. The solid entrainment loss was measured by collected fines during continuous solid circulation condition. Bubbling bed which has an expanded freeboard showed less solid entrainment than the bubbling bed which has a straight freeboard. The cyclone which has a wide gas-solid mixture inlet showed less solid entrainment loss than the cyclone which has a narrow gas-solid mixture inlet. Moreover, the cyclone has a wide gas-solid mixture inlet can capture smaller particles.

• 한국수소및신에너지학회논문집
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• 제30권2호
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• pp.170-177
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• 2019

Continuous solid circulation test at high temperature and high pressure conditions and batch type reduction-oxidation tests were performed to check feasibility of a 0.5 MWth chemical looping combustion system. Pressure drop profiles were maintained stable during continuous solid circulation up to 16 hours. Therefore, we could conclude that the solid circulation between an air reactor and a fuel reactor could be smooth and stable. The measured fuel conversion and $CO_2$ selectivity were high enough even at high capacity and even after cyclic tests. Therefore, we could expect high reactivity of oxygen carrier at real operation condition.

• 한국분무공학회지
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• 제27권2호
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• pp.94-100
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• 2022

Even in non-road UTV (Utility Terrain Vehicle), spark ignition engines are often used to reduce emissions. In this study, gasoline and LPG (Liquified Petroleum Gas) fuels were applied to UTV engines, and the exhaust gas and combustion stability were compared through engine tests. A 0.8-liter two-cylinder SI engine was used in the experiment. Experiments were conducted while changing the IVO (Intake Valve Open) and EVC (Exhaust Valve Close) at 1500 rpm 14 N·m, 40 N·m, and 3000 rpm 17 N·m, 44 N·m conditions. As a result of the experiment, when the valve overlap increased according to the change of IVO and EVC, combustion stability decreased and THC emission increased, but NOx decreased. Comparing the LPG engine with the gasoline engine, the amount of CO₂ and PN (Particulate Number) generation decreased in the LPG engine, and the combustion stability was good.

• 한국수소및신에너지학회논문집
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• 제30권4호
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• pp.312-319
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• 2019

Effect of loop seal geometry on solid circulation characteristics was investigated with two different types of upper loop seals and lower loop seals in a gas-solid fluidized bed system. Upper loop seal which has a wide gap between solid intake and outlet parts requires more fluidization gas to maintain smooth solid circulation. Moreover, the lower loop seal which has a wide gap requires more fluidization gas to achieve the same solid circulation rate. These results can be explained by results of minimum fluidization velocity in the lower loop seals. Consequently, if a loop seal has a wide gap between solid intake and outlet parts, more fluidization gases should be fed to ensure enough solid circulation rate and smooth solid circulation.

• 한국수소및신에너지학회논문집
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• 제31권6호
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• pp.564-570
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• 2020

Metal hydride is suitable for safe storage of hydrogen. The hydrogen storage kinetics of the metal hydride are highly dependent on its heat transfer characteristics. This study presents a metal hydride-expended graphite composite with improved thermal conductivity and its hydrogen storage kinetics. To improve the heat transfer characteristics, a metal hydride was mixed and compacted with a high thermal conductivity additive. As the hydrogen storage material, AB5 type metal hydride La0.9Ce0.1Ni5 was used. As an additive, flakes-type expended graphite was used. With improved heat transfer characteristics, the metal hydride-expended graphite composite stores hydrogen four times faster than metal hydride powder.