• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.667-675
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• 2018

Increasing emissions regulations and demand of high-efficiency cars that travels a lot of distance with less fuel, there is growing interest in Energy Consumption Efficiency. Korean energy consumption efficiency compute combined Fuel Economy by driven city & highway driving mode and present final Energy Consumption Efficiency as using 5-cycle correction formula. Energy consumption efficiency is computed Carbon-balance-method, when used burning fuel play a key role in vehicle performance & Energy Consumption Efficiency. In Korea, vehicle fuel is circulate by Petroleum and Petroleum Alternative Business Act, there is property difference in quality standard because petroleum sector's refine method or type of crude oil. It does not appear a big difference according to fuel, because it sets steady quality standard, it may affect the performance of automobile. Thus, in research We purchase a few diesel fuel which circulated in the market in summer season though directly-managed-gas station by petroleum sector, resolve property each of fuel, we compute Fuel Economy each of them. We analyze into change depend on applying for property as nowadays utilizing Energy Consumption Efficiency calculating formula of gasoline and diesel fuel. As result, Density each of sample fuel has a maximum difference roughly 0.9%, net heat value each of sample fuel has difference 1.6%, result of current Energy Consumption Efficiency each of sample fuel has a difference roughly 1% at city drive mode, 1.4% at highway drive mode. Result of use gasoline calculator formula shows less 6% result than nowadays utilizing Energy Consumption Efficiency calculating formula, each of sample's Energy Consumption Efficiency shows maximum roughly 1.4% result in city & highway drive mode.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.5
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• pp.73-83
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• 2014

CFD(computational fluid dynamics) model is developed to simulate direct injection of ammonia gas phase from ammonia transporting materials into the SCR catalyst in the exhaust pipe of the engine with solid SCR. Configurations of one-hole and four-hole nozzle, circumferential type, porous tube type, and the effect of mixer configurations which commonly used in liquid injection of AdBlue are considered for complex geometries. Mal-distribution index related to concentration of ammonia gas, flow uniformity index related to velocity distribution, and pressure drop related to flow resistance are compared for different configurations of complex geometries at the front section of SCR catalyst. These results are used to design the injection system of ammonia gas phase for solid SCR of target vehicle.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.5
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• pp.85-90
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• 2010

As the environmental regulation of vehicle emission is strengthened, investigations for $NO_x$ and PM reduction strategies are popularly conducted. Two current available technologies for continuous $NO_x$ reduction onboard diesel vehicles are Selective Catalytic Reduction (SCR) using aqueous urea and lean $NO_x$ trap (LNT) catalysts. The experiments were conducted to investigate the $NO_x$ reduction performance of SCR system which can control the ratio of $NO/NO_2$, temperature and SV(space velocity), and the model gas was used which is similar to a diesel exhaust gas. The maximum reduction efficiency is indicated when the $NO:NO_2$ ratio is 1:1 and the SV is 30,000 $h^{-1}$ in $300^{\circ}C$. Generally, ammonia slip from SCR reactors are rooted to incomplete conversion of $NH_3$ over the SCR. In this research, slip was occurred in 6cases (except low SV and $NO:NO_2$ ratio is 1:1) after SCR. Among 6 case of slip occurrence, the maximum conversion efficiency is observed when SV is 60,000 $h^{-1}$ in $400^{\circ}C$.

• Journal of Power System Engineering
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• v.20 no.6
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• pp.93-98
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• 2016

Environmental problems are issued throughout all over the world and which are needed the strength management. In case of the diesel cars are also being developing and studying continuously about various after-treatments device such as EGR, LNT, SCR, DPF and DOC etc. which are used for decreasing $NO_X$ and PM. The air temperature goes up to $39^{\circ}C$ in summer and goes down to $-20^{\circ}C$ in winter because of the location. These changing of the temperature can effect to the engine and harmful exhaust gas discharged and it seems to make the increase - decrease different. The result of the evaluate while changing between the test-mode and the air temperature, which expresses that WLTC-mode is 2.2 times and FTP_75 mode is 4.1~6 times increase to the comparison NEDC-mode of the current regulation. The exhaust characteristic of $NO_X$ by the changing temperature increases in the low temperature and 4.3 times in $14^{\circ}C$ and 21.3 times in $-7^{\circ}C$ with maximum when it compares to $23^{\circ}C$. The fuel efficiency of the different weight car and engine with same data is about 5.7 % in maximum.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.4
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• pp.480-486
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• 2016

Manufacturers have been applying several technologies that can improve the fuel economy of their cars. The regulated voltage control(RVC) system, is one of those technologies being used in passenger cars. In RVC, the voltage of an alternator is controlled depending on the electrical load demand or battery SOC, although each manufacturer differs from another in terms of detail. RVC can reduce the load of an alternator by consuming the stored energy of a battery and simultaneously generate energy. In this paper, a diesel passenger car equipped with an RVC system was tested under FTP-75 and HWFET modes to evaluate fuel economy as their initial battery SOC(100, 90, 80 and 60 %). The test results showed that the initial SOC affects fuel economy only under the FTP-75 mode. FTP-75 fuel economy of the 60% SOC was 13.2 % lower than the 100 % SOC. Also, the simultaneous consumption of the two energy sources did not appear in 60 % SOC.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.5
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• pp.32-38
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• 2006

Currently, due to the serious world-wide air pollution by substances emitted from vehicles, emission control is enforced more firmly and it is expected that the regulation requirements for emission will become more severe. A new concept combustion technology that can reduce the NOx and PM in relation to combustion is urgently required. Due to such social requirement, technologically advanced countries are making efforts to develop an environment-friendly vehicle engine at the nation-wide level in order to respond to the reinforced emission control. As a core combustion technology among new combustion technologies for the next generation engine, the homogenous charge compression ignition(HCCI) is expanding its application range by adopting multiple combustion mode, catalyst, direct fuel injection and partially premixed combustion. This study used a 2-staged injection method in order to apply the HCCI combustion method without significantly altering engine specifications in the aspect of multiple combustion mode and practicality by referring to the results of studies on the HCCI engine. In addition, this study confirmed the possibility of securing optimum fuel economy emission reduction in the IMEP 8bar range(which could not be achieved with existing partially premixed combustion) through forced charging, exhaust gas recirculation(EGR), compression ratio change and application of DOC catalyst.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.1
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• pp.162-170
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• 2007

Currently, due to the serious world-wide air pollution by substances emitted from vehicles, emission control is enforced more firmly and it is expected that the regulation requirements for emission will become more severe. Anew concept combustion technology that can reduce the NOx and PM in relation to combustion is urgently required. Due to such social requirement, technologically advanced countries are making efforts to develop an environment-friendly vehicle engine at the nation-wide level in order to respond to the reinforced emission control. As a core combustion technology among new combustion technologies for the next generation engine, the homogeneous charge compression ignition (HCCI) is expanding its application range by adopting multiple combustion mode, catalyst, direct fuel injection and partially premixed combustion. This study used a 2-staged injection method in order to apply the HCCI combustion method without significantly altering engine specifications in the aspect of multiple combustion mode and practicality by referring to the results of studies on the HCCI engine. And it is investigated that the effects of the engine rpm and load(or A/F) to emission characteristics.

• Journal of Korean Society of Transportation
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• v.33 no.4
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• pp.357-367
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• 2015

This study aims to propose integrated management strategies based on the relationship between co-benefits and total benefits of greenhouse gases and air pollutant emissions for establishing a transport and environmental policy. The results show that the integrated management of the following policies: 'Car Free Day' and 'Early Scrapping of Decrepit Diesel Vehicle', which are used for reducing reduce gasoline and diesel, can together reduce both PM and $CO_2$ emissions and increase total benefits. In addition, the integrated management of 'Car Free Day' with environment policies and 'Congestion Charge' with environment policies simultaneously controls the three factors which influence emissions, including travel volume, travel speed and emissions factor, and was found to be effective in terms of co-benefits. This study reduces both air pollutants, which are harmful to health, and greenhouse gas emissions, which influence climate change, and improves the efficiency of policy through the integrated management of policies.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.6
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• pp.420-429
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• 2008

This paper describes design procedure and control strategy of HDC(High side DC/DC Converter) and MCU(Motor Control Unit) for diesel hybrid electric vehicle. In designing HDC and MCU for HEV high power density and reliability is strongly needed to meet the demand of automotive industry. In order to achieve the high performance of a controller, MPC5554 based control board is developed. An optimized film capacitor and inductor are also developed for high efficiency driving. Skim 63 IGBT module of SEMIKRON for automotive is used for power switching device. The most efficient cooling model for optimal size and reliability were verified by simulation. These procedures are verified by bench or driving test and the results are present in this paper.

• Journal of Energy Engineering
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• v.24 no.4
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• pp.33-41
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• 2015

Dimethyl ether (DME) can be used as a clean diesel alternative fuel due to the high cetane number and low emission, it can also be applied to automotive fuel as a blended liquefied petroleum gas (LPG) because physical properties are similar to those of LPG. In this study, feasibility test of LPG vehicle using blended DME-LPG fuel was investigated. Three types of fuel supply such as LPLi (Liquid phase LPG injection), LPGi (Liquid phase gas injection) and mixer type were selected to consider the LPG fuel-injection system. The performance characteristics of LPG vehicle were examined by using LPG and blended DME-LPG fuel in order to compare the exhaust emissions (CO, THC, $NO_X$) and fuel economy. The emissions and fuel economy of DME-LPG blend fuel were comparable to those of LPG with increasing driving distance.