• 오토저널
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• 제14권3호
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• pp.71-79
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• 1992

Recently, air pollution and energy security problems have necessitated the development of alternative fuel vehicles. As an alternative fuel vehicle FFV(Flexible Fuel Vehicle) which can be operated by and mixture between gasoline and M85(methanol 85% and gasoline 15% by vol. percent) has been drawing great attention. But poor cold startability of high methanol- content fuel which is characteristic of lower fuel volatility and higher latent heat of vaporization than gasoline is one of the major problems to be solved for the development of FFV. In this paper, important factors influencing cold startability of general S.I. engines are described. And, so-me cost-effective and practical methods were investigated in view of the optimization of fuel-ing parameters and ignition system for M85 fuel. The test results showed good startability up to (-22)-(-23).deg.C.

• 한국자동차공학회논문집
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• 제9권2호
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• pp.1-10
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• 2001

In order to reduce hydrocarbon emissions of spark ignition engine, it is important not only to improve catalyst conversion efficiency but also to reduce direct engine out hydrocarbon emissions, during cold starting and warm up process. Tjerefore many researchers have been attracted to develop an early fuel evaporator (EFE) by introducing a ceramic heater for a solution of engine out hydrocarbon emissions in SI engine. But, the performance of the EFE in MPI engine to reduce the exhaust emissions and to improve the cold startability has nat been clarified yet. The purpose of this study is to evaluate the feasibility of a glow plug for EFE.

• 한국자동차공학회논문집
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• 제10권4호
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• pp.7-14
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• 2002

In order to reduce exhaust omissions of spark ignition engine, it is important not only to improve catalyst conversion efficiency but also to directly reduce engine out exhaust emissions, during cold starting and warm up process. Therefore many researchers have been attracted to develop an early fuel evaporator(EFE) by Introducing a ceramic heater fur a solution of engine out exhaust emissions in SI engine. But, the performance of the EFE in MPI engine to reduce the exhaust emissions and to improve the cold startability has not been clarified yet. The purpose of this study is to evaluate the feasibility of a glow plug far EFE. Impinging spray using heated and unheated glow plug helps the vaporization of the fuel and heat up the three way catalyst sufficiently. The amount of CO, and UHC is reduced overall. The amount of NOx is higher at the initial stage, but become lower as time goes on than without glow plug.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2910-2915
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• 2008

This paper was investigated the behaviors of the engine and combustion phenomena for various LPG compositions in the semi-return type system, which is not recircurated to LPG tank through furl rail, applied LPi engine during a cold idle condition and including a cold start of the engine. Cyclic HC and NOx emissions were measured at exhaust port to examine their formation mechanical and reduction mechanical with fast response gas analyzers. Various ignition timing is experimented to study the characteristics of combustion phenomena, HC/NOx emissions during fast idle. Also, this study was investigated start delay time, cylinder pressure, HC/NOx emissions, Mass Fraction Burned, starting time to evaluate performance of transient cold startability. Compared to the return type system, the semi-return type system have advantages in point of production cost and equivalent performance of engine starting time and pressure settling time.

• 한국가스학회지
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• 제18권6호
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• pp.7-13
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• 2014

국내 외에서 대기 오염에 대한 관심은 높은 편이며, 자동차 및 연료 연구자들은 깨끗한 (친환경 대체연료) 연료와 연료 품질에 맞춘 새로운 엔진 설계의 구성, 혁신적인 후처리 시스템 등의 접근을 통하여 차량의 배기가스 배출을 줄이려고 노력하고 있다. 이러한 연구는 다음과 같은 다양한 주요 이슈를 가져오게 된다. PM 배출량이 디젤과 가솔린 차량에 대해 규제해야 하는지 여부와 가솔린 및 LPG 차량이 PM 배출가스 규제에서 무시될 수 있는지 여부이다. 마지막으로 온실 가스 (C$CO_2$, $CH_4$, $N_2O$) 규제가 자동차 배출 규제를 포함하여 논의 것 등이다. 자동차의 온실 가스 및 배출가스(PM)는 환경오염, 건강 악영향 등의 원인으로 많은 문제점을 일으키게 된다. 본 논문에서는 자동차 저온 시동성 및 배출가스에 대해 LPG 연료의 영향을 논의하였다. 또한 본 논문은 시험 온도에 대한 배출가스 특성을 평가하였다. 이때의 시험온도는 시험모드 상의 온도와 국내 겨울철 최저온도를 기준으로 나누어서 실시하였다. 본 연구를 통해 시동성 및 배출가스, 온실가스 배출의 상관관계를 분석하고자 하였다.

• Journal of Mechanical Science and Technology
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• 제16권7호
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• pp.942-949
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• 2002

The use of a combined starter/generator integrated into the drive train of an automobile offers several possibilities for improvement of fuel economy The use of such a starter/generator system is made feasible by a switch from a 14 volts electrical system to a 42 volts system, however, the sizing of the components is not a trivial problem. This study combines a dynamic electromechanical model of the starter, battery and power electronics with the nonlinear mechanics of the piston/crankshaft system and a thermofluid model of the compression and expansion processes to investigate the cold start problem. The example involves the start of an eight cylinder engine at -25 degrees Celsius. This paper shows how the mechatronic V8 engine of an automotive starter/generator system for the startability works well.

• 한국수소및신에너지학회논문집
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• 제28권5호
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• pp.545-553
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• 2017

Microalgae can offer an attractive way of generating renewable and sustainable biodiesel. Biodiesel derived from microagae can have lower impact on the environment and food supply than biodiesel produced from crops. But biodiesel derived from microagae have poor fuel properties at low temperature depending on their species. In this study, it was investigated that fuel characteristics of biodiesel derived from Tetraselmis sp. and cold weather performance of biodiesel blend (BD3, 3 vol.% biodiesel - 97 vol.% diesel). The startability and operability of the passenger car in BD3 was good at $-20^{\circ}C$.

• 에너지공학
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• 제24권2호
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• pp.144-153
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• 2015

저온에서 경유의 파라핀 왁스 생성 및 침전현상은 차량의 저온성능에 악영향을 준다. 본 연구에서는 경유에 바이오디젤, 등유, 저온특성첨가제를 혼합한 연료에 대해 연료조성에 따른 담점, 필터막힘점, 유동점 변화를 분석하였고, 경유의 저온특성에 따른 차량의 저온성능에 대해 평가하였다. 경유는 유동성향상 첨가제(WAFI)와 등유유분의 혼합량이 증가할수록 저온특성이 개선되었으며, 바이오디젤 혼합량이 증가할수록 저온특성이 악화되었다. WAFI는 필터막힘점 개선에, 등유유분은 담점 개선에 효과적이었다. 차량의 저온성능에 대하여 필터막힘점과 유동점의 영향성은 확인하였으나, 담점은 큰 영향이 없었다. 필터막힘점은 차량에 대해 저온에서의 운행가능 한계를 반영하였다.

• 한국산학기술학회논문지
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• 제18권4호
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• pp.711-717
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• 2017

디젤엔진은 저온 상태의 냉시동 조건에서 디젤 미립화 특성 악화로 인한 시동성 및 유해배출가스 생성의 문제를 안고 있다. 본 연구에서는 냉시동 시의 연소개선을 위한 방안으로 다단분사 전략 적용 시의 연소 특성을 파악하고자 하였다. 본 연구에서는 냉시동성 개선을 위해 방안으로 다단분사 적용 시의 연소 특성을 파악하고자 하였다. 정적 연소 챔버 내에 설치한 압력센서를 이용하여 취득한 연소압 및 열방출율, 직접 화염 가시화기법을 적용한 화염강도를 이용하여 연소현상을 분석하고자 하였다. 시험 결과 단일 분사 대비하여 다단 분사 적용 시, 주분사에 의한 최대 연소압력 및 열방출 상승률이 증가하며, 주분사에 의한 화염 감지 기간이 단축됨을 확인하였다. 파일럿 분사량 변경을 통해 분사량 증대 시 파일럿 연소에 의한 열방출 향상에 기인한 주분사에 의한 연소가 개선됨을 확인하였다. 또한 분사압력 증대 시 연료 미립화 개선으로 인한 연소개선을 화염 강도 증대를 통해 확인할 수 있었다. 다만 분사량 및 분사압 증대는 벽면적심현상으로 인한 HC, CO의 배출 수준 악화를 초래할 수 있으므로, 실제 엔진 개발 시 이에 대한 정밀한 선정이 필요할 것으로 판단된다.

• 오토저널
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• 제14권6호
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• pp.67-73
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• 1992

This paper describes Hyundai's research and development work on a flexible fuel vehicle (FFV). The work on FFV has been conducted to evaluate its potential as an alternative to the conventional gasoline vehicle. Hyundai FFV described here can be operated on M85, gasoline, or any of their combinations, in which the methanol concentration is measured by an electrostatic type fuel sensor. For that operation, a special FFV ECU(Eletronic Control Unit) has been developed and incorporated in the FFV. The characteristics affecting FFV operation, such as FFV ECU control strategy and injector flow rate, have been investigated and optimized through the experiment. And various development tests have been performed in view of engine performance, durability, cold startability, and exhaust emissions reduction. The exhaust gas aftertreatment system consisting of manifold type catalyst and secondary air injection system shows good emission reduction performance including formaldehyde, and finally, the possibility of the FFVs as the low emission vehicles is evaluated by presenting NMOG(Non-Methane Organic Gases) levels with respect to M0 and M85. With these results, it is concluded that FFV can be a candidate for the low emission vehicles, but more works on its durability improvement is required.