• Proceedings of the KIPE Conference
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• 2016.11a
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• pp.202-203
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• 2016

최근 화석연료의 환경적인 문제와 경제적인 문제로 인하여 신재생 에너지원을 이용한 마이크로그리드의 연구가 활발히 진행되고 있다. 마이크로그리드는 연계되는 방식으로 AC와 DC 마이크로그리드로 구분한다. 두 마이크로그리드를 하나로 연계하여 장단점을 보완한다. 신재생 에너지원으로 전력을 공급하면 외부조건에 의하여 출력이 변화하게 되는데 에너지 저장장치를 이용하여 이를 보완한다. 또한 에너지 저장장치가 최대 방전이 되었을 때를 대비하여 디젤발전기를 운용한다. 끝으로 계통과 연계모드를 제시하여 독립운전과 계통연계에 대한 운전전략을 제안한다. 제안한 마이크로그리드 운전전략은 PSiM을 통해 시뮬레이션으로 검증하였다.

• Journal of Aerospace System Engineering
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• v.18 no.1
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• pp.64-71
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• 2024

The external fuel tank of an aircraft is a main component that can increase the cruising range of the aircraft. It must be able to be stably separated from the pylon in an emergency situation. At this time, a separation load is applied to the fin and the pivot of the external fuel tank. To stably separate the external fuel tank, the structural soundness of the fin and the pivot must be confirmed. In this study, structural tests were conducted to verify the structural integrity of the external fuel tank pin and pivot when the external fuel tank was separated from the aircraft. Results are then presented. In this paper, a test configuration diagram consisting of the hydraulic and load control equipment, data acquisition system, and pneumatic supply unit used in the structural test was explained. Test installation and test load application plan for each test condition were provided. As results of the structural test, it was found that test load and internal pressure of the test specimen were properly controlled within the allowable range in each test. It was confirmed that serious structural defects in the test specimen did not occur under required load conditions. In conclusion, through structural test for design limit load and design ultimate load, it was proven that the fin and pivot of the external fuel tank for aircraft covered in this study had sufficient structural strength.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1993.05a
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• pp.90-95
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• 1993

수력, 화력, 원자력 다음으로 제 4의 전원으로서 관심의 대상이 되고 있는 연료전지는 연료가 가지고있는 화학에너지를 직접에너지로 변환시키는 점에서 종래의 발전 기술과는 원리적으로 다르며, 카르노(Carnot)사이클에 의한 에너지 변환 효율의 제한을 받지 않기 때문에 효율이 높으며 공해가 없는 특징을 가지고 있다. 연료전지의 발전 방식은 작동 온도, 전해질 등에 의해서 분류되나 현재 실용화단계의 기술은 인산형연료전지 발전이다. 인산형 연료전지의 발전용 연료는 천연가스, 메탄올, 납사 등과 같은 탄화수소 계열의 다양한 연료를 사용할 수 있으며, 이들 연료들을 수소가 많이 함유된 가스로 변환시켜 연료전지에 공급하여야 한다. 연료전지발전시스템 개발은 주로 전력이용 측면에서 천연가스를 개질연료로 사용하는 연구가 주류를 이루었으나, 최근에는 전 세계적으로 대기 공해에 시달리고 있는 도시의 환경개선을 위하여 도심용 버스 및 대형 트럭 등에 응용하기 위한 무공해 수송용 자동차엔진의 개발, 국방용 이동전원 개발 및 100㎾ 미만의 현지설치용 및 낙도용 전원으로서 메탄올을 연료로 한 연료전지의 개발이 활발히 진행되고 있다. 한국에너지기술연구소는 한국전력 기술연구원과 공동으로 1989년부터 1992년까지 본체를 제외한 5.9㎾급 인산형 연료전지 발전시스템 즉, 메탄올 연료 개질장치, 운전자동화 시스템, 배열이용 시스템, 종합 배관 등을 설계 구성하여 발전 플랜트의 운전 특성 연구를 수행하였으며, 본 고에서는 이들 설비들의 운전 특성과 발전 플랜트로서의 효율 특성에 대한 고찰을 수행하였다. 본 시스템은 연료개질기가 연결되고 배열을 이용하는 국내최초의 종합적인 연료전지 발전 시스템으로서 개질된 연료로 운전하였을 경우 본체의 효율은 31.9%, 배열을 회수한 종합발전 플랜트의 효율은 45.2%였다.로서, 흰쥐 유선이 LH의 생성처이면서 동시에 작용처이며 유선에서 합성된 GnRH의 조절하에 국부적인 인자로 작용할 가능성을 시사한다.f variation)가 10% 내외로 만족할 만한 범위에 들었다. 본 실험 방법을 타액과 혈청내 testosterone 농도 측정에 응용하여 RIA의 결과와 비교하여 본 바 상관관계가 타액에서 r=0.969, 혈청에서 r=0.990으로 두 결과가 잘 일치하였다. 본 실험에서 측정된 한국인 여성의 타액내 testosterone농도는 107.7$\pm$12.0 pmol／l이었고, 남성의 타액내 농도는 274.2$\pm$22.1 pmol／l이었다. 이상의 결과로 보아 본 연구에서 정립된 EIA 방법은 RIA를 대신하여 소규모의 실험실에서도 활용할 수 있을 것으로 사려된다.또한 상실기 이후 배아에서 합성되며, 발생시기에 따라 그 영향이 다르고 팽창과 부화에 관여하는 것으로 사료된다. 더욱이, 조선의 ${\ulcorner}$구성교육${\lrcorner}$이 조선총독부의 관리하에서 실행되었다는 것을, 당시의 사범학교를 중심으로 한 교육조직을 기술한 문헌에 의해 규명시켰다.nd of letter design which represents -natural objects and was popular at the time of Yukjo Dynasty, and there are some documents of that period left both in Japan and Korea. "Hyojedo" in Korea is supposed to have been influenced by the letter design. Asite- is also considered to have been "Jap

• Clean Technology
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• v.23 no.3
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• pp.331-342
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• 2017

To estimate the combustion characteristics of sewage sludge and wood pellet, thermogravimetric analysis (TGA) was conducted. As TGA results, combustion characteristics of sewage sludge was worse than wood pellet. In ash fusion temperature (AFT) analysis, slagging tendency of sewage sludge is very high compared to wood pellet. And also, the bubbling fluidized bed reactor with a inner diameter 400 mm and a height of 4300 mm was used for experimental study of combustion characteristics fueled by sewage sludge and wood pellet. The facility consists of a fluidized bed reactor, preheater, screw feeder, cyclone, ash capture equipment and gas analyzer. The thermal input of sewage sludge cases were $54.5{\sim}96.5kW_{th}$, in case of wood pellet experiment, it was $96.1kW_{th}$. As experiment results, the $NO_x$ emission of sewage sludge was averagely about 10 times the $NO_x$ emission of wood pellet. And also CO emission of sewage sludge is about 3.5 times of wood pellet. Lastly as a result of analysis of captured ash in cyclone, the combustion efficiency of all cases were over 99%, but the potential for slagging/fouling was high at all cases by component analysis of ash.

• Journal of IKEEE
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• v.18 no.3
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• pp.420-426
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• 2014

In this paper, we have implemented the low temperature fluidity test system with the composited fuel filter and heater, which has tested the low temperature fluidity of gasoline, an engine start time, the consumption of electricity and power to evaluate the system performance. The test condition have used the diesel fuel, the normal temperature, the diesel fuel supply pressure $3.4kgf/cm^2$ at $-20{\sim}-30^{\circ}C$, the fuel supply quantization 60 l/H, the setting current 30 A and the voltage $13V_{dc}$. In order to simulate the operation of diesel fuel filter, we will establish the composited fuel filter into test jig, and be filled with chamber tank and filter by a constant flow quantization and pressure. After these, it shall be cold for setting time. And then we have measured the consumption current and power of heater, an operating time and pressure of filter.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2005-2010
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• 2011

Since recently exhaust gas regulation for a non-road small engine as well as commercial vehicle engine has been enforced, a carburettor of a small engine should be replaced by an electronic fuel injection system. In this study, the spray characteristics of the 400cc gasoline small engine injector has been experimentally analyzed. Based on the experimental results, suitable injector for the small engine has been selected. Through the test rig measuring spray mass distribution, fuel distribution characteristics of 3 hole- and 6 hole-injector has been analyzed. Through the visualization equipment, injector spray angle, penetration length and spray width have been measured and analyzed. Considering spray characteristics and stability, 6 hole-injector is selected for the 400cc gasoline small engine.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.7
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• pp.689-696
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• 2010

The Because of its high thermal efficiency, the direct injection (DI) diesel engine has emerged as a promising potential candidate in the field of transportation. However, the amount of nitrogen oxides ($NO_x$) increases in the local high-temperature regions and that of particulate matter (PM) increases in the diffusion flame region during diesel combustion. In the de-$NO_x$ system the Lean $NO_x$ Trap (LNT) catalyst is used, which absorbs $NO_x$ under lean exhaust gas conditions and releases it in rich conditions. This technology can provide a high $NO_x$-conversion efficiency, but the right amount of reducing agent should be supplied to the catalytic converter at the right time. In this research, the emission characteristics of a diesel engine equipped with a micro-reformer that acts as a reductants-supplying equipment were investigated using an LNT system, and the effects of the exhaust-gas temperature were also studied.

• Clean Technology
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• v.23 no.1
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• pp.80-89
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• 2017

The bubbling fluidized bed (BFB) reactor with a diameter of 0.1 m and a height of 1.2 m was used for experimental study of co-firing and emission characteristics fueled by sewage sludge (SS) and wood pellet (WP). The facility consists of a fluidized bed reactor, feeding system, cyclone, condenser and gas analyzer, The mean particle diameter and minimum fluidization velocity are $460{\mu}m$ and $0.21ms^{-1}$ respectively. SS produced from Korea and WP from Canada were examined. The various mixing ratios of WP were 20, 50, and 80% based on HHV. The equivalence ratio of 1.65, reactor temperature of $800^{\circ}C$, air flow rate of $100Lmin^{-1}$, and fluidization number of 4 were fixed in the BFB experiment. In TGA, the range of combustion temperature of SS was wider than that of WP. It represents that the combustibility of WP is higher than that of SS. The BFB reactor temperature was maintained between 800 and $900^{\circ}C$. CO emission of SS was high because of lower combustibility. $NO_X$ and $SO_X$ formation of SS were higher than that of WP since high nitrogen and sulfur contents of SS. CO, $NO_X$, and $SO_X$ formation were suppressed as the mixing ratio of WP was increased. The slagging and fouling tendencies show high in all test conditions.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.4
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• pp.59-70
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• 2021

An experimental study was conducted to observe the spray characteristics for different flow rates and rotating speeds of a rotating fuel nozzle of a slinger combustor. The water spray ejected from the nozzle orifice was visualized using a high-speed camera and a light source. It was confirmed that the atomization was improved, as the flow rate decreased and rotating speed increased. The characteristic maps for the spray characteristics and performance parameters showed that the aerodynamic Weber number and the liquid-air momentum flux ratio were associated with the liquid primary breakup, and the liquid-air momentum flux ratio and Rossby number were closely correlated with the liquid ejection mode.

• Analytical Science and Technology
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• v.23 no.1
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• pp.45-53
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• 2010

For the determination of chlorine in uranium compound, analytical methods by using a steam distillation and a pyrohydrolysis have been developed. The steam distillation apparatus was composed of steam generator, distilling flask and condenser etc. The samples were prepared with an aliquot of LiCl standard solution and a simulated spent nuclear fuel. A sample aliquot was mixed with a solution containing 0.2 M ferrous ammonium sulfate-0.5 M sulfamic acid 3 mL, phosphoric acid 6 mL and sulfuric acid 15 mL. The chloride was then distilled by steam at the temperature of $140^{\circ}C$ until a volume of $90{\pm}5\;mL$ is collected. The pyrohydrolysis equipment was composed of air introduction system, water supply, quartz reaction tube, combustion tube furnace, combustion boat and absorption vessel. The chloride was separated from powdered sample which is added with $U_3O_8$ accelerator, by pyrohydrolysis at the temperature of $950^{\circ}C$ for 1 hour in a quartz tube with a stream of air of 1 mL/min supplied from the water reservoir at $80^{\circ}C$. The chlorides collected in each absorption solution by two methods was diluted to 100 mL and measured with ion chromatography to determine the recovery yield. For the ion chromatographic determination of chlorine in molten salt retained in a metal ingot, the chlorine was separated by means of pyrohydrolysis after air and dry oxidation, and grinding for the sample.