• Journal of Energy Engineering
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• v.11 no.2
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• pp.160-165
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• 2002

The heavy-duty LPG-fueled single cylinder engine was designed and developed as a fundamental equipment for analyzing combustion processes and emission performances. The cylinder head and the piston crown were modified to fire the LPG in the engine. The flywheel was also fabricated to minimize the vibration of the single cylinder engine. The size of bore and stroke of the tested engine are 130 mm and 140 mm, respectively. Compression ratios were varied 8 to 9 with different piston crown shapes. The developed single cylinder engine operates at 1,000 rpm for this work. The major conclusions of this work are; (1) the power of the developed engine was peaked at the condition of equivalence ratio 1.0 at three different compression ratios; (2) the power is slightly increased with the increase of compression ratio; (3) the optimum ignition timing is retarded with the increase of compression ratio ranged 2 to 10 crank angle.

• LP가스
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• s.71
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• pp.49-53
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• 2000

대형디젤엔진의 대체용으로 LPG 엔진을 개발함에 있어서 차세대 연료공급방식인 LPG 연료의 액상분사방식을 채택하여 기존의 믹서방식의 연료공급시스템을 가진 LPG 엔진보다 고출력, 고효율, 저공해성을 추구하고자 하였다. 이를 위한 기초연구로서 먼저 단기통 연소엔진을 이용하여 대형엔진에 LPG 연료 적용 가능성, 액상분사 시스템을 포함한 여러 가지 연료공급방식에 따른 엔진의 성능파악, 대형엔진에 적합한 최적 선회비의 결정, 연료조성에 따른 엔진성능의 변화 등을 알아보았다. 실험결과, 대형엔진에 LPG 연료의 적용은 아무런 문제점이 없었으며 LPi 연료공급방식은 다른 방식에 비해서 10%정도의 체적효율 및 출력의 증가를 확인할 수 있었다. 최적의 선회비는 2.0 부근에서 형성되었고, 연료 조성은 프로판 대 부탄의 비율이 60 : 40에서도 정상적으로 운전됨을 확인하였다. 시제품 엔진의 경우, 과급방식의 KL6i 엔진을 개발하기 앞서 좀더 기술적 접근이 용이한 자연흡입방식의 K-1엔진의 개발이 선행되었으며 현재 개발 진행중인 K-1엔진의 성능평가 결과, 기존의 디젤엔진에 비해 출력성능이 20% 정도 향상됨을 확인할 수 있었다. 특히 대형차량에서 중요시 생각되는 저속토크 성능이 매우 우수한 것으로 파악되었다. 이러한 결과를 바탕으로 단기통 연소엔진에서 확인된 최적화된 연료조성과 선회비를 향후 K-1엔진에 적용할 예정이다. 최근 열린 가스학회 추계발표회와 LPG자동차세미나의 주요내용을 게재한다.

• Journal of Energy Engineering
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• v.14 no.3 s.43
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• pp.173-179
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• 2005

Fuel injection system has more benefits in power, fuel consumption and emission than carburetor system even in high speed small engine. Up to date fuel injection system is used in motor car but is not used in motorcycles in Korea. EFI (Electronic fuel injection) system which has ECU can control precise fuel supply to variable RPM in engine. The purpose of this study is the investigation of effects of fuel injection system to improve the engine performance and efficiency in variable revolution of high speed small engine which is 4 Valves SOHC single cylinder engine used in motorcycle.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.2082-2087
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• 2004

In this study, the variation of spark plug location in the combustion chamber was investigated for the sake of emission characteristics from SI engine by using PDA valve. The swirl is ong of the important parameters that effects emission characteristics. PDA valve has been used to satisfy the requirements of sufficient swirl generation to improve combustion and emission reduction to effect on flow profile on a combustion chamber. Especially, the variation of spark plug location have an important effect to analyze exhaust gas and the early flame propagative process. Therefore, this test is forced that injection timing, spark timing and intake air motion govern the stable combustion. From the results, it showed that the variable spark plug location and PDA valve can be reduced exhaust gas.

• Tribology and Lubricants
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• v.11 no.3
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• pp.40-47
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• 1995

The engine oil life was examined experimentally for small size single cylinder engines. This study was conducted in the laboratory. An Eddy Current type engine dynamometer was used with a motorcycle and a cultivator engine. Physical and chemical properties of used oil was analyzed to examine the oil life. Flushed oil was used for the reference instead of the new oil. It were found that deterioration of dynamic viscosity and anti-wear property of engine oil was due to dilution by fuel not depletion of ZDTP.

• 한국가스학회:학술대회논문집
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• 2000.09a
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• pp.137-142
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• 2000

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.5
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• pp.108-115
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• 2014

In this study, experimental approaching method was applied under and single-cylinder engine to research the performance of direct needle-driven piezo injector (DPI) for CR direct-injection. As key-point factor of this DPI that relies on direct-acting operating of injector needle, unlike conventional hydraulic-servo, its nozzle needle can be directly driven by piezo actuator. Thus, effect of direct-acting injection of DPI on diesel combustion and emission characteristics was investigated under common-rail single-cylinder direct-injection engine, equipped with three different driving mechanism, including indirect-acting solenoid, piezo and DPI system. As main results, it found that a direct-acting piezo injector has higher of IMEP. And it has higher heat release rate during premixed combustion and mixing controlled combustion phase due to its higher heat release, even though nitrogen oxide (NOx) formations were increased slightly.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.3
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• pp.336-343
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• 2017

Intake air conditions, such as air temperature, pressure, and humidity, are very important parameters that influence engine performance including combustion and emissions characteristics. The purpose of this study is to investigate the effects of intake air temperature on combustion and exhaust emissions characteristics in a single cylinder diesel engine. In this experiment, an air cooler and a heater were installed on the intake air line and a gas flow controller was installed to maintain the flow rate. It was found that intake air temperature induced the evaporation characteristics of the fuel, and it affects the maximum in-cylinder pressure, IMEP(indicated mean effective pressure), and fuel consumption. As the temperature of intake air decreases, the fuel evaporation characteristics deteriorate even as the fuel temperature has reached the auto-ignition temperature, so that ignition delay is prolonged and the maximum pressure of cylinder is also reduced. Based on the increase in intake air temperature, nitrogen oxides(NOx) increased. In addition, the carbon monoxide(CO) and unburned hydrocarbons(UHC) increased due to incomplete fuel combustion at low intake air temperatures.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1995.06a
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• pp.18-24
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• 1995

본 연구에서는 두가지 엔진에 사용된 엔진오일의 성상변화를 측정하였다. 따라서 금속 마모입자 분석, 동점도 측정과 TAN 및 TBN 분석을 통한 물리적 성상과 화학적 성질 분석 그리고 적외선 분광 분석과 정량 폐로그라피 분석 등을 통하여 Table 1에 나타난 기준에 의해 오일의 수명을 판정하였다. 아울러 RPD를 이용하여 마모입자의 형상 등을 분석하고 엔진에서 발생하는 마모기구를 살펴보았다. 물론 본 연구는 주위 환경이 양호한 실험실에서 엔진 동력계에 의한 실험에 의존하였으므로 실제 주행실험 결과보다는 오일의 수명이 더 길게 나타날 것으로 예측된다. 더욱이 농경지에서 주로 사용되는 경운기의 경우는 오일이 먼지나 모래, 진흙 등에 의해 오손되기 쉬우므로 실제 오일의 수명은 훨씬 더 짧을 것으로 생각되므로 실차 주행실험 결과와의 비료는 앞으로 더 연구할 분야로 생각된다.

• Journal of Power System Engineering
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• v.8 no.4
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• pp.5-10
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• 2004

본 연구는 단기통 4행정 기관의 배기단의 형상에 따른 실험과 수치해석이 소개되었다. 흡 배기 밸브가 작동하고 있고, 주요한 배기단의 변수로는 배기단 직경이 적용이 되었다. 실험결과로는 배기단의 직경에 따라 배기 압력은 많은 영향을 받았는 것으로 나타났다. 배기단의 직경이 감소하였을때, 배기압력파의 진폭과 파수가 증가되었다. 배기단의 직경이 증가 하였을 때, 배기압력파의 진폭이 감소하였다. 직경이 22mm 일 때의 소음의 주파수 분석이 16mm와 28mm 보다 진폭이 작게 나타났다.