• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.508-513
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• 2009

Significant air temperature increases in urban areas are known as the heat island phenomenon in a global scale. Therefore, we use numerical model in order to analyze quantitative effects by using new & renewable energy on the heat island phenomenon in urban area. The present study quantitatively analyzes the Urban Heat Island Effects, Energy-Saving Effects, and Environmental Load Decrease Effect along New and Renewable Energy Application which is 10% of the Building Energy Consumption.

• 한국수소및신에너지학회논문집
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• 제17권3호
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• pp.293-300
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• 2006

KIER has been developing a Ru-based preferential oxidation catalysts and a novel fuel processing system to provide hydrogen rich gas to residential PEMFCs system. The catalytic activity of Ru-based catalysts was investigated at different Ru loading amount and different support structure. The obtained result indicated that 2 wt% loaded Ru-based catalyst supported on ${\alpha}-Al_2O_3$ showed high activity in low temperature range and suppressed the methanation reaction. The developed prototype fuel processor showed thermal efficiency of 78% as a HHV basis with methane conversion of 92%. CO concentration below 10 ppm in the produced gas is achieved with separate preferential oxidation unit under the condition of $[O_2]/[CO]=2.0$. The partial load operation have been carried out to test the performance of fuel processor from 40% to 80% load, showing stable methane conversion and CO concentration below 10 ppm. The durability test for the daily start-stop and 8 h operation procedure is under investigation and shows no deterioration of its performance after 50 start-stop cycles. In addition to the system design and development.

• 한국수소및신에너지학회논문집
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• 제17권3호
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• pp.248-254
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• 2006

The promotion effects of noble metals upon the activity and reducibility in steam methane reforming over $Ni/MgAl_2O_4$ catalysts were investigated. While $Ni/MgAl_2O_4$ catalysts require the pre-reduction by $H_2$, the noble metal-added catalysts show high catalytic activities without pre-treatment. According to $CH_4$-TPR, the addition of noble metal makes the $Ni/MgAl_2O_4$ catalyst easily reducible. The reduction degree of NiO in the noble metal-added catalysts after using at $650^{\circ}C$ without pre-reduction was $15{\sim}20%$, and was lower than that in the $H_2$-reduced $Ni/MgAl_2O_4$ catalyst(reduction degree=27%). The enhancement of the catalytic activity over noble metal-added catalysts results from easier reducibility by addition of noble metal and the synergy effect between noble metal and Ni.

• 한국수소및신에너지학회논문집
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• 제20권2호
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• pp.116-124
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• 2009

We investigated the influences of cobalt coating deposited by DC electroplating on the ferritic stainless steel, STS 430, as a protective layer on a metallic interconnect for SOFC applications. Cobalt coated STS 430 revealed a uniform and denser-packing oxide surface and a reduced growth rate of $Cr_2O_3$ scales after oxidation at $800^{\circ}C$in air. Cobalt coating layer was oxidized to $CoCo_2O_4$ and Co containing mixed oxide spinels such as $Co_2CrO_4$, $CoCr_2O_4$, and $CoCrFeO_4$. The area specific resistance value of Co coated sample was $0.020\;{\Omega}cm^2$ lower than that of uncoated at $800^{\circ}C$ in air during 500 h. After 1000 h oxidation, cobalt oxide coating layer suppressed chromium outward diffusion.

• 한국수소및신에너지학회논문집
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• 제20권6호
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• pp.455-463
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• 2009

코발트 보호막 코팅이 적용된 페라이트계 스테인리스 스틸인 STS 430과 STS 444 소재에 대해 고체산화물 연료전지용 금속연결재로서의 고온 산화 특성에 대해 살펴보았다. 코발트 코팅층은 $800^{\circ}C$ 고온 산화 후 코발트 산화물 및 $Co_2CrO_4$, $CoCr_2O_4$, $CoCrFeO_4$ 등과 같은 코발트가 함유된 스피넬 상을 형성하였다. 또한 페라이트계 스테인리스 스틸과 코발트 코팅의 계면에서 크롬과 철이 함유된 치밀한 산화층을 형성하여 금속연결재 표면의 스케일 성장속도를 감소시키고 금속연결재 내에 함유된 크롬의 외부 확산을 효과적으로 억제하였다. 한편 STS 430은 고온 산화 후 표면에 형성된 스케일 하부에 $SiO_2$와 같은 내부 산화물이 형성된 반면 STS 444는 표면 스케일 이외에 다른 내부 산화물은 확인되지 않았으며 고온에서의 면저항 측정 결과, 코발트가 코팅된 STS 444의 전기 전도성이 STS 430 보다 우수한 것으로 나타났다.

• 에너지공학
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• 제20권4호
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• pp.267-277
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• 2011

후발국에서의 신재생에너지기술의 개발은 어떤 힘에 의해서 추동될까? 후발국의 '녹색 성장'은 '녹색'의 가치 실현을 위해서 추동되는가 아니면 '성장'을 지속하기 위한 새로운 분야의 개척인가? 본 연구는 한국의 신재생에너지 기술개발사업 사례 분석을 통해 후발국 신재생에너지기술개발의 동력에 대한 이해를 돕고자 한다. 환경문제와 기술개발, 기술개발과 '사회기술연맹' 그리고 후발국 '권위주의적 발전국가론'에 대한 기존의 논의를 통해 기술 개발의 동력은 사회기술연맹의 구성에서 찾을 수 있다는 것에 착안하여 연구의 틀을 구성하였고 이를 토대로 선발국 덴마크와 독일의 사례를 분석한 후 한국의 신재생에너지기술개발사업 사례를 분석하였다. 한국은 선진국과는 다르게 산업계와 정부 주도의 성장동맹을 바탕으로 신재생에너지기술개발이 추진되었고 환경시민단체는 정부의 시민단체 국정 참여 정책에 힘입어 신재생에너지정책협의회에 참여함으로써 사회기술연맹을 구성하였다. 따라서 한국의 신재생에너지 사회기술연맹은 '녹색'의 가치 실현보다는 '성장'중심이라는 한계를 갖는다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
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• pp.281-286
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• 2008

Current feed-in tariffs(FIT) of Electricity generating from new and renewable energy sources are reappraised with the corrected formula of levelized generation cost(LGC) of utility power. The LGC of new and renewable electricity should be formulated in explicitly reflecting the capital cost and corporate tax during the economic life cycle based on its realistic application data. An applicable term of the FITs should, especially, be equal to the economic life cycle. The revised FITs issued in 2006 were, however, derived from the incorrect formula described in the study of KERI(Korea Electrotechnology Research Institute), and consequently misestimated. The reappraisal values for FIT of new and renewable electricity were shown and interpreted in this paper. An FIT of PV more than 30 kW, for example, should be 972.86 won/kWh instead of current 677.38 won/kWh increasing 43.6%. An upward revision of other FITs for new and renewable electricities should also be required in the range of 8.6% to 47.3%.

• 설비공학논문집
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• 제23권8호
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• pp.556-561
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• 2011

In this study, the theoretical maximum power of a heat engine was investigated by sequential Carnot cycle model, for a low-grade heat source of about $100^{\circ}C$. In contrast to conventional approaches, the pattern search algorithm was employed to optimize the two design variables to maximize power. Variations of the maximum power and the optimum values of design variables were investigated for a wide range of UA(overall heat transfer conductance) change. The results show that maximizing heat source utilization does not always maximize power.

• Journal of Power Electronics
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• 제19권4호
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• pp.858-868
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• 2019

With the widespread use of modern clean energy, lithium-ion batteries have become essential as a more reliable energy storage component in the energy Internet. However, due to the difference in monomers, some of the battery over-charge or over-discharge in battery packs restrict their use. Therefore, a novel multiphase interleaved converter for reducing the inconsistencies of the individual cells in a battery pack is proposed in this paper. Based on the multiphase converter branches connected to each lithium battery, this circuit realizes energy transferred from any cell(s) to any other cell(s) complementarily. This flexible interlaced converter is composed of an improved bi-directional Buck-Boost circuit that is presented with its own available control method. A simulation model based on the PNGV model of fundamental equalization is built with four cells in PSIM. Simulation and experimental results demonstrate that converter and its control achieve simple and fast equalization. Furthermore, a comparison of traditional methods and the HNFABC equalization is provided to show the performance of the converter and the control of lithium-based battery stacks.

• 한국수소및신에너지학회논문집
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• 제23권1호
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• pp.100-109
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• 2012

In this paper, some ideas are proposed to establish the infrastructure of all-electric houses which are able to reduce primary energy consumption and $CO_2$ emission by adopting heat pump systems and induction heating cookers excluding the use of fossil fuel energy. This electrification concept is based on the consumption of only one type of energy which means electricity as secondary energy and the conventional fossil fuel energy is just consumed to generate electricity as primary energy. All-electric house is laid on the extension of the hydrogen economy in a long-term viewpoint so that the effectiveness of this new conceptual house is estimated analyzing the reduction of $CO_2$ emission. In this analysis, the balance of electricity supply and demand is considered including the construction of new power plants by renewable energy such as nuclear, IGCC and fuel cell because decarbonization is an essential element of hydrogen technology and economy and this action is accomplished in both supply and demand side of electricity. The results are able to contribute to develop various useful hydrogen policies and strategies and some detail researches are required previously to make the best application of this new conceptual house.