• International Journal of Automotive Technology
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• 제6권4호
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• pp.429-436
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• 2005

In this paper, operation algorithms are evaluated for a fuel cell hybrid electric vehicle (FCHEV). Power assist, load leveling and equivalent fuel algorithm are proposed and implemented in the FCHEV performance simulator. It is found from the simulation results that the load leveling algorithm shows poor fuel economy due to the system charge and discharge efficiency. In the power assist and equivalent fuel algorithm, the fuel cell stack is operated in a relatively better efficiency region owing to the battery power assist, which provides the improved fuel economy.

• 한국분무공학회지
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• 제16권2호
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• pp.97-103
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• 2011

The electronically controlled diesel engine was converted to dual fuel engine system. Test engine was set up for investigating the power output, thermal efficiency and emissions. ND 13-mode tests were employed for the engine test cycle. The emission result of dual fuel mode meets Euro-4 (K2006) regulation and the engine performance of dual fuel engine was comparable to the performance of diesel engine. To estimate economical efficiency, test vehicles have been operated on a certain driving route repeatedly. Fuel economy, maximum driving distance per refueling and driveability were examined on the road including free ways. Developed vehicle can be operated over 500 km with dual fuel mode and shows 80% of diesel substitution ratio. Driveability of dual fuel mode is similar with that of diesel mode.

• 한국자동차공학회논문집
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• 제15권1호
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• pp.16-22
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• 2007

Fuel efficiency is one of the major issues in regard to energy and environment. As customers desire more comfortable vehicles, increase of accessory traction force is necessary. Air conditioning system (ACS) consumes the biggest traction force among accessories, especially during summer. This means ACS is the primary object deteriorating fuel economy among accessories. Since direct measurement of traction force and fuel consumption in practical vehicle is difficult, comparison analysis is taken between vehicle with and without ACS working. For this comparison, real time measurements are carried out to know ACS traction force and fuel consumption. As a result of the comparison, a vehicle without ACS operation was 15.92% superior to a vehicle with ACS operating. It could be used as a fundamental material for improvement ACS for better fuel efficiency.

• 한국산학기술학회논문지
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• 제12권1호
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• pp.19-25
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• 2011

최근의 차량 연비는 환경 규제 및 고가의 연료 가격으로 인하여 중요한 문제로 대두되었다. 연비 향상을 위한 기술 개발은 엔진, 파워트레인 등 차량의 많은 구성품들의 성능을 개선하였다. 따라서 연비는 많이 향상 되었으나 연비 측정은 현재도 주어진 모드(LA-4, FTP-75 등)에서 컴퓨터 모의시험 및 다이나모에서 수행한다. 본 논문에서는 실제 도로의 연비 향상 방안을 도출하기 위하여 약 213Km 영동고속도로를 제안하는 3가지 다른 알고리즘으로 모의 주행하였다. 이를 위해 GPS 수신 데이터 중에서 거리와 고도 데이터를 추출하여 각 구간의 경사도, 주행저항을 계산, 알고리즘에 따른 속도 프로파일을 약 213Km 전 구간에 대해서 완성하였다. 이 속도 프로파일로 컴퓨터를 이용한 AVL Cruise 프로그램으로 모의 주행하여 연비를 산출하고 Eco-driving 방안을 제안한다.

• 자원ㆍ환경경제연구
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• 제22권2호
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• pp.329-365
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• 2013

본 연구의 목적은 2000-2009년 국가별로 환경과 화석에너지의 제약 하에서 경제와 환경의 효율을 측정하고자 함이다. 본 연구는 국가별 소득수준에 따른 OECD국가, 중고소득국가, 저소득국가 등 세 그룹으로 구분하여, 생산가능집합에서 바람직한 산출물인 GDP와 오염물을 동시에 포함한 '환경지향형, 경제지향형, 환경-경제지향형, Two-stage DEA모형' 등의 네 가지 방법을 제시하여 비교한다. OECD국가는 상대적으로 경제효율성이 높으나 환경효율성은 낮았고 비OECD국가는 환경효율성이 높고 경제효율성이 낮았다. 화석에너지와 온실가스의 저감의 여지는 OECD국가가 더 높았다.

• 한국산업융합학회 논문집
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• 제23권6_2호
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• pp.949-956
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• 2020

It's important to measure fuel consumption of vehicles. It's possible to monitor green house gas from vehicles for various traffic conditions with the measured data. It's effective to eco-drive for drivers with fuel consumption data also. There's a display of fuel consumption in the modern vehicles, but it's not useful to get the data from the display. An estimating method for fuel consumption of a vehicle is suggested in the study. It's a simple but an effective method using GPS data. The GPS data(speed, acceleration, road slope) and vehicle data(weight, frontal area, model year, certified fuel economy) is necessary to estimate the fuel consumption for the method. It calculates driving resistance force to estimate engine power. Then it estimates the necessary fuel consumption to maintain the engine power with fuel-power conversion factor. The conversion factor is corrected with certified fuel economy, model year and rated power. The precision of the methods is checked with road test data. The test driving data was measured with GPS and OBD. The error of the estimated fuel consumption for the measured one is about 1.8%. But the error is large for the 1000 and 100 data number from the total data number of about 10,000. The error is from the larger change range of the GPS data than the one of the measured fuel consumption data. But the proposed estimating method is useful to percept the fuel consumption change for better fuel economy with simple gadget like smart phone or other GPS instruments.

• 한국자동차공학회논문집
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• 제23권4호
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• pp.410-419
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• 2015

In this study, the roadability, fuel economy and emission characteristics were evaluated for a natural gas converted vehicle. The results are as follows; Not only the shortage of power was observed in stall test, but also large deterioration of acceleration performance was exposed in roadability. Compared to the original LPG system, the acceleration is 76% in start acceleration and 45 ~ 65% in overtaking acceleration, especially the decline became larger when air conditioner is at work. Furthermore, because the mapping data, which controls the injection depending on driving condition, do not match up with injection system, the failure of air-fuel ratio feedback control occurs resulting from the large gap between the required and the really supplied amount of fuel. This failure cause the exhaust gas to emit without catalytic conversion and the fuel economy based on the fuel heat value to get worse 22% in the mode test and 16% in road test respectively. In addition, the existing injection system does not secure enough fuel at the starting so that it may lead to the fail of clod start, the deterioration of hot start and inharmonic of engine at the idle after start.

• 한국자동차공학회논문집
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• 제9권5호
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• pp.23-29
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• 2001

This paper is the second of companion papers, which investigate port-masking effects on emission and fuel economy. Port-masking was applied to commercial SOHC 3-valve engine by inserting masking plates between manifold and port. To induce various conditions of stratification, six types of masking plates were applied. In this paper, main interest is focused on the influence of injection timing on emission and fuel economy. Various injection timing was applied to the six cases, under the stoichiometric and lean-limit air-fuel ratio. Under the stoichiometric condition, an explanation about the reason of the change in emission level due to injection timing change is given. It is observed that NOx emission under the LML condition varies significantly when the injection timing changes.

• 한국자동차공학회논문집
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• 제11권6호
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• pp.30-36
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• 2003

Variable valve timing(VVT) mechanisms are used widely for improving fuel consumption and reducing emissions. Most of application, however, are limited in the DOHC engine. Dual equal retard/advance strategy is relatively simple one and can be applied to both SOHC and DOHC engines. In this study, effects of dual equal valve timing retard/advance are investigated to observe the feasibility of VVT system on an SOHC SI engine. The result shows that fuel economy and emissions are improved in the dual retard condition due to increased internal EGR. Some amount of increase in volumetric efficiency can be achieved by advancing valve timing at low speed and by retarding at high speed. In this case, however, full load power is not so much improved as the volumetric efficiency increases because of severe knock. In the dual advance condition, there is no merit in the fuel economy and emission.

• 융복합기술연구소 논문집
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• 제5권1호
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• pp.23-26
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• 2015

The purpose of present study is to analysis the Characteristics of fuel economy and Green house gases due to the driving mode conditions of The hybrid electric vehicle(HEV). HEVs are divided into mild and power types according to the their functions. mild type HEVs are inexpensive because they do not need to implement a pure electric mode. Power type HEVs are more expensive but has also better fuel efficiency. In the present paper, the test results for the gasoline vehicle using FTP-75 mode and HWFET are present.