• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.273-275
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• 2014

An ammonia fuel system is developed and applied to both a spark ignition engine and a compression ignition engine to use ammonia as primary fuel in this study. Ammonia is injected separately into the intake manifold in liquid phase while gasoline or diesel is also injected as secondary fuel. As ammonia burns 1/6 time slower than gasoline or diesel, the spark or diesel injection timing is needed to be advanced to have better combustion phasing. The test engine showed quite high variation in the power output with large amount of ammonia. The final goal of the study is to implement a methodology to ignite ammonia-air mixture and have complete combustion without any use of the conventional fuels.

• 한국연소학회지
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• 제11권4호
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• pp.14-21
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• 2006

In this study, syngas which is reformed from fossil fuel and has hydrogen as a major component, was added to a gasoline engine to improve combustion stability and exhaust emissions of idle state. Syngas fraction of the total supplied fuel varied to 0 %, 25 %, 50 % with various ignition timing and excess air ratio. Combustion stability, exhaust emissions, fuel consumption and exhaust gas temperature were measured to investigate the effects of syngas addition on idle performance. Results showed that syngas has ability to widely extend lean operation limit and ignition retard range with dramatical reduction of engine out emissions. It is supposed that the usage of syngas in the internal combustion engine is an effective solution to meet the future strict emission regulations.

• 에너지공학
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• 제23권3호
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• pp.221-230
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• 2014

Simplified finite element model of spark ignition (SI) engine to analyse combustion heat transfer is presented. The model was discredited with 3D thermal elements of global length 5 mm. The fuel type is petrol. Internal nodal temperature of cylinder body is defined as 21000C to represent occurrence of gasoline combustion. Material information and isotropic material properties are taken from published report. The heat transfer analysis is done for the instant of combustion. The model is validated by comparing the computed maximum temperature at the piston surface with the published result. The computed temperature gradient at the crucial parts are plotted and discussed. It has been found that the critical top surface suffered from thermal and the materials used to construct the engine parts strongly influenced the temperature distribution in the engine. The model is capable to analyze heat transfer in the engine reasonably and efficiently.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.321-324
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• 2009

The unpredicted worldwide oil price makes the energy efficiency technology be more importance than any other period. The small cogeneration system is one of the most representative technology among the energy efficiency technologies, and recently, the household cogeneration system has been the center object of attention because of the loss of power transmission and the reasonable energy consumption relative to the household (condensing) boiler producing heat only. A tiny, 1kW of electrical output, gas fueled internal combustion engine cogeneration system was investigated. The electrical efficiency and thermal efficiency of the system were measured. With the emission characteristics, the cogeneration system was analyzed. It was showed the gas engine cogeneration system produced the lowest NOx level compared any other cogeneration system due to the three-way catalyst.

• Advances in Automotive Engineering
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• 제1권1호
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• pp.105-121
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• 2018

The hybrid electric powertrain is a robust solution that allows for major improvements in both fuel economy and emission reduction. In the present study, a through-the-road hybrid vehicle model with an electric motor driving the rear axle and an Internal Combustion Engine (ICE) driving the front axle has been constructed. We then present a systematic method for the determination of a real time applicable optimal Energy Management Strategy (EMS) for a hybrid road vehicle. More precisely, we compare the performance of rule-based EMS strategies to an optimization-based strategy, namely ECMS (Equivalent Consumption Minimization Strategy). The comparison is conducted in parallel with a parameterization of the size of the internal combustion engine and the implementation of a Continuously Variable Transmission (CVT) that allows following the line of best fuel economy. For the FTP-75 driving cycle, the constrained engine On-off control algorithm is shown to offer a 28% improvement potential of fuel consumption compared to the conventional internal combustion engine while the ECMS strategy achieves an improved potential of nearly 33%.

• 한국자동차공학회논문집
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• 제16권4호
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• pp.151-158
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• 2008

Gasoline Homogeneous Charge Compression Ignition (HCCI) combustion is a new combustion concept. Unlike the conventional internal combustion engine, the premixed fuel mixture with high residual gas rate is auto-ignited and burned without flame propagation. There are several operating factors which affect HCCI combustion such as start of combustion (SOC), residual gas fraction, engine rpm, etc. Among these factors SOC is a critical factor in the combustion because it affects exhaust gas emissions, engine power, fuel economy and combustion characteristics. Therefore SOC of gasoline HCCI should be controlled precisely, and SOC detection should be preceded SOC control. This paper presents a control oriented SOC detection method using 50 percent normalized difference pressure. Normalized difference pressure is defined as the normalized value of difference pressure and difference pressure is difference between the in-cylinder firing pressure and the motoring pressure. These methods were verified through the HCCI combustion experiments. The SOC detection method using difference pressure provides a fast and precise SOC detection.

• 한국자동차공학회논문집
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• 제16권3호
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• pp.66-72
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• 2008

Fuel reforming technology for the fuel cell vehicles could be adopted to internal combustion engine for the reduction of engine out emissions. Since syngas which is reformed from fossil fuel has hydrogen as a major component, it has abilities to enhance the combustion characteristics with wide flammability and high speed flame propagation. In this paper, syngas was feed to 2.0 liter gasoline engine during the cold start and early state of idle condition. Not only cold start HC emission but also $NO_x$ emission could be dramatically reduced due to the fact that syngas has no HC and has nitrogen up to 50% as components. Exhaust gas temperature was lower than that of gasoline feeding condition. Delayed ignition timing, however, resulted in increased exhaust gas temperature approximated to gasoline condition. It is supposed that the usage of syngas in the gasoline internal combustion engine is an effective solution to meet the future strict emission regulations by the reduction of cold start THC and $NO_x$ emissions.

• Journal of Advanced Marine Engineering and Technology
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• 제38권3호
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• pp.233-239
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• 2014

엔진성능 분석을 위해서는 기관의 정확한 출력이 기본적으로 중요한 인자이며, 또한 오늘날 내연기관에서 연소압력 분석 장치는 엔진의 연구와 개발, 환경규제 및 엔진의 유지관리를 위해서 필수 장비로 대두 되고 있다. 엔진의 출력뿐만 아니라 연소상태를 분석하여 엔진의 상태에 대한 올바른 판단을 유도하고, 구체적인 개선방법을 제시하여 실질적으로 연료소비량을 절감하여, 엔진의 유지관리 및 운항비 절감에 도움이 되도록 하기위해서는 이를 위한 도구가 절실히 필요하다. 따라서 본 연구는 개발된 측정 장치를 이용하여 선박용 발전기관인 실험엔진의 연소분석을 행하였으며, 실험기관의 불규칙적인 연소상태를 체크하고 재조정하여 안정된 운전 상태를 유지할 수 있었음은 물론 연료절감에 기여할 수 있었다. 이상의 결과로 엔진출력을 정확하게 측정할 수 있는 새로운 방법에 의한 측정 장치가 개발되었으며, 그 유용성이 입증되었다고 판단된다.

• 한국자동차공학회논문집
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• 제14권6호
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• pp.9-16
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• 2006

Variable valve timing is one of the attractive ways to control homogeneous charge compression ignition (HCCI) engine. Hot internal residual gas which can be controlled by variable valve timing(VVT) device, makes fuel evaporated easily, and ignition timing advanced. Regular gasoline was used as main fuel and di-methyl ether(DME) was used as ignition promoter in this research. HCCI engine operating range is limited by high combustion peak pressure and engine noise. High combustion pressure can damage the engine during operation. To avoid engine damage, the rich limits have to define using various methods. Peak combustion pressure, rate of cylinder pressure rise was considered to determine rich limit of engine operating range. Knock probability was correlated with the rate of cylinder pressure rise as well as the peak combustion pressure.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.291-295
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• 2004

New valve driving system to control for the best volumetric efficiency at each load of an internal combustion engine within one engine cycle has been developed. The system needs to reduce pumping loss that cause by throttle valve during the intake valve is opened. In this system the intake valve is driven by a linear DC electromagnetic actuator which is controlled by personal computer. The result is compared both installed and uninstalled actuator into the cylinder head. By both of experimental and numerical calculation, the responsibility of the valve driving system to the engine speed was examined