• Journal of Energy Engineering
• /
• v.15 no.3 s.47
• /
• pp.194-201
• /
• 2006

Greenhouses should be heated during nights and cold days in order to fit growth conditions in greenhouses. Ground source heat pump (GSHP) systems are recognized to be outstanding heating and cooling systems. A horizontal GSHP system with thermal storage tank was installed in greenhouse and investigated the performance characteristics. The reasons for using thermal storage tank were discussed in detail. Thermal storage tank can provide heat for heating load that is larger than GSHP system heating capacity. The results of study showed that the heating coefficient of performance of the heat pump system was 2.69.

• Explosives and Blasting
• /
• v.25 no.1
• /
• pp.45-52
• /
• 2007

When emulsion explosives(1kg/cartridge) are loaded into a long vertical borehole at open blasting site, they undergo an Impact corresponding to 117.6J of shock energy. After shocking. the crystallization of emulsion nay happen immediately. Furthermore, it nay cause a desensitization, arising from increase in the density of emulsion explosive by the breakage of sensitizer. In this paper, some experimental work was performed using PVC pipe equipment(50mm diameter and 12m lengths) to investigate the effects of loading impart of emulsion explosive. It is shown that detonation energy decreases up to 26% of the normal state value and this effect is less than 3% of the total performance of emulsion explosives in borehole blasting.

• 한국방재학회:학술대회논문집
• /
• 2011.02a
• /
• pp.30-30
• /
• 2011

국내의 내진설계 기준은 1988년에 처음 도입되었으며, 최근 점차 강화되고 있는 실정이다. 공동주택에 주로 적용되는 전단벽식 구조시스템에서 증가된 지진력에 저항하기 위해서는 벽량과 철근이 증가하게 되어 공사비가 상승하게 된다. 이러한 단점을 보완하기 위한 제진설계의 필요성이 대두되고 있는 실정인데, 기존의 제진장치는 주로 가새형 또는 벽체형을 대부분이라 평면계획에 제약이 있다. 따라서 전단벽식 구조의 공동주택의 제진설계 시에는 우리나라와 같은 중 약진 지역에 적합하고 저렴한 비용으로 충분한 내진성능과 평면의 가변성을 확보할 수 있는 댐퍼의 선택이 필요하다. 본 연구의 목적은 기존의 가새형 및 벽체형 제진장치의 국내 공동주택 적용시의 문제점인 평면의 가변성 확보에 유리하고, 수동형 제진장치의 장점을 추구할 수 있는 마찰댐퍼를 삽입한 커플링보 제진시스템의 내진성능을 조사하는 것이다. 내진성능을 평가하기 위해서 실대형 커플링보 실험체를 계획하고 제작하였다. 실험체는 2개로 구성되어 있으며, 하나는 기존의 철근배근 상세를 갖는 철근콘크리트 커플링보 실험체와 커플링보에 마찰댐퍼가 삽입된 실험체이다. 횡하중에 대한 성능을 평가하기 위해서 유사정적 반복가력실험을 실시하였다. 엑츄에이터로부터 실험체 상보의 가력지그를 통해 하중이 전달되도록 하였으며, 가력은 최초 0.25%의 층간변형각부터 변위제어를 통해 목표 층간변형각인 1.5% 이상까지 진행되도록 하였다. 실험결과, 두 실험체의 이력곡선과 에너지 흡수능력을 평가하였다. RC 실험체는 핀칭현상이 관찰되었고, 가력이 진행됨에 따라 커플링보와 벽체에서의 균열이 확산되어 종국적으로 취성적인 커플링보의 전단파괴가 발생하였다. 마찰댐퍼를 삽입한 실험체는 계획된 마찰거동이 잘 발휘되어 목표 층간변형각인 1.5%까지 이선형거동이 잘 나타났다. 최대 내력은 RC 실험체가 3배 이상 크지만, 누적층간변형각에 따른 에너지 흡수능력은 마찰댐퍼 실험체가 2배 이상 우수한 결과를 보였으며, 커플링보 및 벽체에서의 균열이 매우 저감되었다.

• Applied Chemistry for Engineering
• /
• v.32 no.6
• /
• pp.627-631
• /
• 2021

Research on induction heating catalyst system was conducted to solve problems of the existing catalyst system for removing volatile organic compounds. In the present study, three types of Ni-based commercial catalysts were employed, and induction heating reaction characteristics including the catalyst volume, composition, heat treatment atmosphere, and position in the coil were investigated. The composition and volume of the catalyst affected the exothermic and toluene oxidation performance in the induction heating system. In particular, the Fe-added catalyst showed high exothermic performance compared to that of other catalysts consisting of more than 99% Ni, but had low toluene oxidation performance. In addition, the heat treatment in an air atmosphere of the Ni-based catalyst drastically reduced the performance. In the induction heating system, the optimal condition for the catalyst was to be located in the center of the coil. The catalyst showed similar activities among seven repeated experiments under the optimal condition derived from this work.

• Journal of Energy Engineering
• /
• v.28 no.1
• /
• pp.37-44
• /
• 2019

Domestic buildings account for 25% of national greenhouse gas emissions and 20% of energy consumption, so energy efficiency improvement of buildings is recognized as the main target of national energy demand management. To improve the energy efficiency of the building, policies are implemented by preparing "zero-energy building national roadmaps" and enhancing the efficiency of national energy demand management through early activation as a result of expansion of the mandatory zero-energy building. Also, there is a growing need to verify the performance of energy savings after the construction is completed. Therefore, methods for evaluating energy performance of buildings should be suggested. This paper aims to develop and present methods for verifying energy performance of Zero Energy School, which can be applied internationally, by visiting domestic schools on-site at the same time as international standards and guidance analysis.

• Journal of Energy Engineering
• /
• v.7 no.1
• /
• pp.35-43
• /
• 1998

Electrodes using for the anode electrode of direct methanol fuel cell with Pt/C and Pt/Ru/C catalyst were prepared and characterized by SEM, TEM, thermal analysis and electrochemical analysis. The half cell tests were carried out with 1 M $H_2SO_4$ electrolyte and 1 M $CH_3OH$ in order to evaluate the electrode performance. The employed electrochemical methods were cyclic vol-tammetry and potentiodynamic polarization experiments. It was found that 20 w% polytetrafluoroethylene (PTFE) content in catalyst showed the best performance due to the best platinum utilization on PTFE-containing catalyst layer. It was found that Pt/Ru/C binary catalyst inhibited the poisoning of anode electrode showing improved performance compared to the Pt/C catalyst by the adsorption of oxygen containing species on the electrode surface at same time. The apparent activation energy for methanol oxidation on the Pt/Ru/C and Pt/C catalyst layer was 11.60 kJ/mol and 26.85 kJ/mol, respectively.

• Korean Chemical Engineering Research
• /
• v.61 no.4
• /
• pp.611-618
• /
• 2023

The purpose of the refueling protocol and the contents of SAE J2601, which is used as the basis for hydrogen vehicles refueling around the world, were investigated, and research contents related to domestic protocols were also investigated. In addition, the components of the hydrogen refueling performance evaluation device developed in Korea and the method for evaluating the performance and safety of hydrogen refueling stations were reviewed. And, the result were analyzed by applying it to the hydrogen refueling stations currently operating in Korea. In addition, an economic feasibility analysis was conducted using data collected from domestic hydrogen refueling stations. In order to secure the safety and economy of a hydrogen refueling station, the protocol must be satisfied, and in order to satisfy the protocol, it is necessary to evaluate whether the refueling temperature, refueling pressure, and refueling flow are controlled within a safe range.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.23 no.5
• /
• pp.1-12
• /
• 2019

The purpose of this study is to enhance the seismic performance of exposed column-base plate weak-axis connections for small-sized steel buildings. According to the site inspection for the small-sized building construction, the arbitrary connection details in steel buildings have been applied at the job site, which is considered to be insufficient to guarantee structural safety and stability considering the increased seismic risk in Korea. Therefore, a series of test programs had been done to develop enhanced connection details in order to ensue the adequate seismic stability and safety of small-sized steel buildings. From the test results, It was found that the exposed column-base plate weak-axis connections commonly used in Korea shows very poor seismic behavior due to the "Rocking" phenomena caused by the residual plastic deformation of anchor bolts between anchor plate and concrete. A series of hysteretic tests for finding that solution were conducted to reduce the "Rocking" phenomena of the column-base plate connections, and local buckling of webs in H-column. Finally the enhanced stable seismic behavior was obtained by reinforcing at least 8 anchor bolts with good bonding strength and stiffeners to the webs in H-column.

• 한국신재생에너지학회:학술대회논문집
• /
• 2005.06a
• /
• pp.150-153
• /
• 2005

반도체성 고분자인 poly(3-hexylthiophene) (P3HT)과 $C_{60}$ 유도체인 PCBM의 복합재를 이용하여 유기태양전지를 제작하였다. 열처리 온도론 중심으로 다양한 제조조건 하에서의 태양전지 특성을 조사하였다. 열처리 온도를 높임에 따라, P3HT/PCBM 복합재 박막은 뚜렷한 색변화와 함께 가시광 영역에서의 광흡수가 증가됨이 관찰되었고, 소자 성능도 크게 향상되었다. 결과적으로, 본 P3HT/PCBM bulk 이종접합형 구조의 유기 태양전지는 최적화된 제조 조건에서 $2.8\%$의 에너지 전환 효율을 나타내었다($100mW/cm^2$, 백색광).

• Journal of the korean Society of Automotive Engineers
• /
• v.8 no.2
• /
• pp.22-30
• /
• 1986

메탄올 자동차의 도입은 공해책연에서나, 대체연료면에서 중요한 과제라는 인식하에서 일본우수 성은 벌써부터 그의 열현을 목표로 개조차에 의한 성능테스트 실시 등의 여러 가지 준비를 하여 왔는데, 최근에는 자동차 공해대책의 견지에서 디젤엔진을 탑재하여 사용중인 트럭 및 버스에 대 하여 경유대신으로 깨끗한 연료의 사용을 요망하는 소리가 높아지고 있다. 또 운수부문에서도 석유대체에너지의 도입이 요망되고 있어, 메탄올 자동차는 다른 대체에너지를 사용하는 것에 비 해서 기술적, 경제적으로 가장 실용성이 높고, 도입이 준비기간이 짧기 때문에 매우 유망시되고 있다. 자동차연료로서의 메탄올에는 몇가지 문제점이 있다고 지적되기도 하였으나 현재는 모두 기술적 대응이 이루어져 메탄올 자동차의 실용화를 저해하는 문제는 거의 없다고 하겠다. 뿐 만아니라 매탄올의 원료가 되는 천연가스는 세계적으로 대량, 광범하게 존재하고 있어 석유가 격면에서도 대량생산이 궤도에 오르게 되면 경유와 비슷하게 될 가능성이 있다. 따라서 메탄올 자동차는 금후 적극적으로 도입을 추진하여야 할 것이며, 도시버스, 시내집배 트럭 등에 사용되면 자동차공해대책, 에너지 대책의 측면에서 상당히 큰 효과가 기대될 수 있을 것이다. 이러한 메 탄올이 석유대체연료로서 안착될 때까지는 당연히 조성조치가 필요하며 전입을 방해하는 과제는 없어야 할 것이다.