• 한국자동차공학회논문집
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• 제8권6호
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• pp.60-69
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• 2000

In order to obtain underwater or underground power sources, the closed cycle diesel engine is operated in the non air-breathing circuit system where the major species of the working fluid include oxygen, argon, and recycled exhaust gas. In the present study, the closed cycle diesel engine is designed to operate at the intake pressure between 2 and 3 bar. For operating in the open-cycle and closed-cycle situations, experimental apparatus using this diesel engine is made with ACAP as data acquisition system. In open, semi-open, and closed cycle modes, the predicted p-$\theta$ and P-V are compared with load bank power. Computation have been performed for wide range of major experimental parameters such as the specific fuel and oxygen concentrations, fuel conversion efficiency and polytropic exponent, IMEP and maximum cylinder pressure.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2002년도 제24회 KOSCO SYMPOSIUM 논문집
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• pp.133-139
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• 2002

The lean premixed technique has been proven very efficient in reducing NOx emissions from gas turbine combustors. However combustion instability is susceptible to occur in lean premixed combustor. So laboratory-scale dump combustor was used to understanding the underlying mechanisms causing combustion instabilities. In this study, tests were conducted at atmospheric pressure and inlet air was up to $360^{\circ}C$ with natural gas. The observed instability was a longitudinal mode with a frequency of ${\sim}341.8Hz$. At selected unstable conditions, phase-resolved OH chemiluminescence images were captured to investigate flame structure with various equivalence ratio. Combustion instability was observed to occur at higher value of equivalence ratio(>0.69). This study was performed to investigate the effects of equivalence ratio and fuel split measuring NOx and acoustic wave. The results reveal the effect of fuel-air unmixedness on lean premixed combustor.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제37회 추계학술대회논문집
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• pp.415-418
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• 2011

비선형적인 연소불안정 현상 이해를 위해서는 압력 섭동에 대한 화염 반응 특성 파악이 중요하다. 이전 연구는 스피커에 의한 연료와 공기 혼합체 섭동에 대한 난류, 층류 예혼합 화염의 반응, 그리고 화염에 직접 축 방향 압력파를 가진하는 경우로 나뉜다. 본 연구에서는 액체로켓엔진 연소환경을 모사한 연소화염의 횡 방향 가진파에 대한 화염 응답 함수 파악을 위한 실험 장치를 고안하여 제시하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.84-88
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• 1989

Recently electronic control of engine is used to satisfy exhaust gas restriction and to increase fuel economical efficiency and acceleration. In this paper, Smith-predictor method is applied to increase control performance for A/F command and disturbance. A/F control performance is simulated by A/F command and disturbance of Chevolet 5.7 liter engine and Toyota 4A-ELU engine. This method can be applied to A/F controller so that lion accurate and rapid A/F control is possible.

• 전기저널
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• 통권362호
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• pp.17-19
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• 2007

지난 2006년은 고유가체제의 지속 및 국내경기 성장세가 저하됨에 따라 전력판매 증가율이 둔화되고 전력설비 사고가 빈발 등 많은 어려움이 있었던 한 해였다. 그러나 이러한 역경속에서도 임직원 모두가 하나 되어‘변화와 혁신’에 매진한 결과 대내외적으로 높은 성과를 인정받아 많은 수상을 받은 한 해이기도 했다. 그 대표적인 것으로 세계 전력산업계 최고의 권위를 자랑하는 에디슨상을 수상하였으며, 미국 Platts誌로부터는 아시아·태평양 최우수전력회사로 선정되는 쾌거를 이룩하였다. 또한 국내에서도 공기업 고객만족도 8년 연속 1위라는 전무후무한 기록을 달성하였으며, 공기업으로는 최초로 옴부즈만 대상을 수상하기도 하였다. 금년에도 집단에너지사업자 및 구역전기사업자 등 판매부문에서의 경쟁체제 확대와 수입 발전연료가격의 고공행진에 의한 구입전력비 상승 등 경영여건의 어려움이 예상되나 글로벌경제확산에 따라“국제경쟁력 제고만이 경쟁에서 살아남아 국가 경제발전에 이바지 할 수 있다”는 믿음으로 올 한 해에도 다음 주요사업의 차질 없는 추진을 위해 최선을 다하고자 한다.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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• pp.86-87
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• 2005

The combustion characteristics of the D.I. diesel engine are largely dependent on the air-fuel ratio and the gas exchange process. The main factors are the shape of combustion chamber, fuel injection system, air flow inside the cylinder, intake air mass flow rate and so forth. Because these factors affect the combustion in a mutual and combined manner, it is very important to clearly understand the correlation of these factors in order to provide the combustion improvement plans. In this paper, we studied the performance and the gas exchange process of marine four-stroke engine using the engine cycle simulation. Also, we predicted briefly turbocharger engine matching.

• 대한기계학회논문집B
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• 제31권1호
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• pp.62-67
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• 2007

Optimization of cathode properties for intermediate temperature-operating SOFC (IT-SOFC) is carried out by using composite-type electrode structure in this study. Composite cathode may lower cathode overpotential by enhancing mixed ionic-electronic conductivity. In this study, particularly, LSM/YSZ, LSF/YSZ, LSCF/CGO, and PSC/CGO were selected as cathode materials. LSM/YSZ composite cathode showed the best performance of about 0.9${\Omega}cm^2$ at $700^{\circ}C$. It is inferred that the resistance is mainly affected by the reactivity between cathode and electrolyte which can cause the formation of resistive phases. Area specific resistance (ASR) characteristics were not changed significantly with decreasing sintering temperature of cathode, because reaction sites were increased even with worse adhesion of cathode on electrolytes.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.658-662
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• 1990

In the air-fuel control of automotive engine to improve its efficiency, fuel economy and less emissions, conventional control methods using $O_{2}$ sensor or the lean air-fuel ratio sensor provide only open control in rich conditions. Control with a wide range air-fuel sensor makes it possible to employ closed loop control for all engine conditions including rich combustion. With a wide range A/F sensor and A/F transfer functions, a PID control system is constructed which employs an learning scheme. A/F controller is designed which enables to improve the ability of its compensation for sensors and actuators, and its control operation is evaluated by computer simulation.

• 대한기계학회논문집
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• 제18권2호
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• pp.397-404
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• 1994

Smoke is emitted in diesel engines because fuel injected into the high-temperatured and high-pressured combustion chamber burns with its mixture with insufficient oxygeny. In consideration of air pollution, above all, it is necessary to illuminate the cause of smoke emission in diesel engines. The smoke emission, which is characteristic of diffusion combustion in diesel engines, results from pyrolysis of fuel not mixed with air. Therefore the smoke emission is dependent on diffusion combustion quantity, which is in turn controlled by engine parameter. The study aims at making clear and interpreting the interdependence of smoke emission in diesel engines with heat released within combustion chamber, camparing diffusion combustion quantity according to each engine parameter (air fuel ratio, injection timing, and engine speed), and showing the relation between smoke emission and fraction of diffusion combustion through experiment.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2010년도 한국컴퓨터종합학술대회논문집 Vol.37 No.1(D)
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• pp.416-419
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• 2010

본 논문은 친환경 운전(Eco Driving)에 대한 사회적, 기술적 관심이 고조되고 있는 현 상황에서 차량에서 제공하는 차량 정보 가운데 MAF 센서 값을 이용하여 차량의 주행 연비를 추정하고자 하였다. MAF는 화학반응에서 연료 1g당 혼합되는 공기의 양을 의미하며, g/s의 단위를 사용한다. 휘발유 차량의 경우 엔진 ECU에서 폐회로 제어를 통해 혼합비를 14.7:1로 일정하게 유지하는 동작을 수행하므로 우리는 MAF 값을 통해 차량의 주행 연비 추정이 가능하다. 본 논문에서는 국내에서 생산중인 차종들에 대해 MAF 값을 이용한 실제 주행 테스트 수행하였으며, 이에 대한 연비 결과를 종합적으로 비교 분석하였다.