• Asian Journal of Atmospheric Environment
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• v.2 no.1
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• pp.34-46
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• 2008

Emissions inputs for use in air quality modeling of Korea were generated with the emissions inventory data from the National Institute of Environmental Research (NIER), maintained under the Clean Air Policy Support System (CAPSS) database. Source Classification Codes (SCC) in the Korea emissions inventory were adapted to use with the U.S. EPA's Sparse Matrix Operator Kernel Emissions (SMOKE) by finding the best-matching SMOKE default SCCs for the chemical speciation and temporal allocation. A set of 19 surrogate spatial allocation factors for South Korea were developed utilizing the Multi-scale Integrated Modeling System (MIMS) Spatial Allocator and Korean GIS databases. The mobile and area source emissions data, after temporal allocation, show typical sinusoidal diurnal variations with high peaks during daytime, while point source emissions show weak diurnal variations. The model-ready emissions are speciated for the carbon bond version 4 (CB-4) chemical mechanism. Volatile organic carbon (VOC) emissions from painting related industries in area source category significantly contribute to TOL (Toluene) and XYL (Xylene) emissions. ETH (Ethylene) emissions are largely contributed from point industrial incineration facilities and various mobile sources. On the other hand, a large portion of OLE (Olefin) emissions are speciated from mobile sources in addition to those contributed by the polypropylene industry in point source. It was found that FORM (Formaldehyde) is mostly emitted from petroleum industry and heavy duty diesel vehicles. Chemical speciation of PM2.5 emissions shows that PEC (primary fine elemental carbon) and POA (primary fine organic aerosol) are the most abundant species from diesel and gasoline vehicles. To reduce uncertainties in processing the Korea emission inventory due to the mapping of Korean SCCs to those of U.S., it would be practical to develop and use domestic source profiles for the top 10 SCCs for area and point sources and top 5 SCCs for on-road mobile sources when VOC emissions from the sources are more than 90% of the total.

• New & Renewable Energy
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• v.1 no.3 s.3
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• pp.42-50
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• 2005

This paper deals with the economic feasibility model and analysis of a hydrogen fuel-cell vehicle [FCV] against two similar types of non-business vehicles fueled with gasoline [GV] and diesel [DV] considering greenhouse gas [GHG]. Considering the price of vehicles and annual operating cost, we build a classical economic feasibility model. Since the economic feasibility could be affected by many input factors such as the prices of vehicles, the price of fuels, annual driving distance and so on, we estimate the average future values of input factors, which is defined as "the average case". Based on the average case, we assess the representative economic feasibility of a FCV with/without GHG, and by changing various annual driving distances, we assess its economy in terms of net-present value, internal rate of return, and payback period. In addition, we make some sensitivity analysis of its economic feasibility by changing the values of the critical input factors one at time. Based on the average case, it turns out that the consumer of a FCV could save 25,000 won/year for a GV, but the consumer could pay 120,000 won/year more for a DV. This indicates that gasoline vehicles could be replaced gradually by FCVs in Korean market which might be formed by those consumers driving annually more than approximately 14,800 km. As the results of our sensitivity analysis, it turns out that a FCV is no more economical if the difference of the prices between FCV and GV is more than 10,130,000 won or the price of hydrogen fuel could be more than 5,136 won/kg.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.8
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• pp.1547-1552
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• 2017

Unlike diesel locomotives, electric vehicles have various issues because they have very quiet engine sound. For example, pedestrians are exposed to the dangerous electric vehicles on the road because they can not recognize the electric vehicles' sound. Moreover, the driver is unable to recognize how fast driver's car is driving at a certain speed. To solve these problems, electric cars' sound needs to be artificially implemented and played. This paper examines the problems of the previous sampling engine sound approach. In this paper, instead of using sampling sounds, we developed a novel synthesizer algorithm via programming languages as a software. In experimental results, we demonstrated and verified our proposed synthesizer's approach is superior to the previous sampling approach. In addition, through these synthesizer's approach, we highly expect the proposed synthesizer's approach will give safety, convenience and comfort to the electric vehicles' users.

• Journal of Power System Engineering
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• v.18 no.6
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• pp.77-83
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• 2014

As the interest on the air pollution is gradually risen up at home and abroad, their vehicle emission regulations have been reinforcing by steps. PM regulation was also reinforced 4times for the last 13years and has been applied to SI vehicles after EURO 5. Additionally, knowing that small particles of PM can easily penetrate deep into lungs PM number was added on the regulation from EURO5+ and is applied to CI vehicles. Also, PN regulation is going to be applied to SI vehicles. But, because the regulation is appled to only a general test mode of each countries that is performed at $25{\pm}5^{\circ}C$, it is unclear whether the regulation can work on the other ambient temperature conditions or not. In this paper, to know that exhaust emission characteristics at the special conditions CI vehicles(CRDi w, w/o DPF) were tested using 5-cycle mode, NEDC mode at 5-ambient temperatures (35, 25, 0, -7 and -15) and the exhaust emission test results were discussed. The results show that the vehicle with DPF emits much low PM(and PM number) on all of the test mode. However, NOx of the other mode was emitted higher than regulation mode. Also. NOx was sharply increased according to decreasing Ambient Temperature.

• Clean Technology
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• v.15 no.1
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• pp.1-8
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• 2009

The adoption of compressed natural gas (CNG) as a vehicle fuel is a common phenomenon as it is accelerating worldwide. Increasing number of CNG driven vehicles around the world has jumped up from one million in 1996 to five million in 2006. CNG as a vehicle fuel is very popular to the end users because of its clean-burning properties and cost effective solution compared to other alternative fuels like diesel and gasoline. The use of CNG as a fuel reduces vehicular emission that is consisted of carbon monoxide (CO), hydrocarbons (HC), oxides of nitrogen ($NO_x$), carbon dioxide ($CO_2$) etc. This research highlights the characteristics of CNG vehicles, CNG arrangement in the vehicles, CNG fueling procedures and most importantly the environmental and economic factors that are highly considered as cost effective solution for the flexibility of using CNG in the automobiles.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.1
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• pp.109-116
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• 2011

To measure the traffic pollutants with high temporal and spatial resolution under real conditions a mobile emission laboratory (MEL) was designed and built in KIST with close-cooperation with KIMM and Yonsei university. The equipment of the mini-van provides gas phase measurements of CO, NOx, $CO_2$, THC (Total hydrocarbon) and number density & size distribution measurements of fine and ultra-fine particles by a fast mobility particle sizer (FMPS) and a condensation particle counter (CPC). The inlet sampling port above the bumper enables the chasing of different type of vehicles. This paper introduces the construction and technical details of the MEL and presents data from the car chasing experiment of diesel and CNG city bus. The dilution ratio was increased rapidly according to the chasing distance. Most particles from the diesel city bus were counted under 300 nm and the peak concentration of the particles was located between 40-60 nm. However, the most particles from the CNG city bus were nano particle counted under 50 nm.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.5
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• pp.13-19
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• 2014

Urea-SCR system is the selective catalytic reduction to reduce nitrogen oxides ($NO_x$) emitted from diesel vehicles. The objective of this study is numerical analysis of 3-dimensional unsteady melting problems of frozen urea by using an electric heater. It can be applied to determine capacity of power with respect to time and the location of the urea suction pipe in urea storage tank. The study includes the change of liquid volume fraction, temperature profiles and a influence of natural convection by using the commercial software STAR-CCM+(v7.06). The accuracy of the numerical analysis is estimated by comparisons with experimental data. After validation, a numerical analysis for freezing urea is conducted with four different heating power. From the results, it was found that relation of velocity of phase interface and amount of melting urea by increasing heating power in a container. There is also a difference in trend between velocity of phase interface and amounts of melting urea because of effect of natural convection.

• Journal of ILASS-Korea
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• v.16 no.1
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• pp.1-6
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• 2011

In recent years, the need for more fuel-efficient and lower-emission vehicles has driven the technical development of alternative fuels such as LPG (Liquefied Petroleum Gas) which is able to meet the limits of better emission levels without many modifications to current engine design. LPG has a high vapor pressure and lower viscosity and surface tension than diesel and gasoline fuels. These different fuel characteristics make it difficult to directly apply the conventional gasoline or diesel fuel pump. Self acting lubricated groove design or coating can be used in high-speed and high precision spindle system like a roller-vane type fuel pump, because of its advantages such as low frictional loss, low heat generation, averaging effect leading better running accuracy and simplicity in manufacturing. Those design method can also affect the atomization of fuel from the injector and the formation of fuel film on the intake manifold. In this study, experiments are carried out to get performance characteristics of initial and steady state operation, The characteristics of vane type fuel pump were investigated to access the applicability on LPLi engine.

• Journal of the Korean Applied Science and Technology
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• v.30 no.3
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• pp.528-539
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• 2013

Biodiesel is one of the most important renewable energy, since it is one of the most important alternative and eco-friendly energy source compared to fossil energy, especially for diesel engineequipped vehicles. It is now coming up for preparation of biodiesel as the alternative that applies the hetrogeneous catalyst, super critical state and various methods used in order to reduce the stages of the processes be converted and separation stages started from oil and fat which are originated from animals and wastes, and those new methods bring eco-friendly as well, though some of those are stand on research step so far. It is necessary that nation provides the tax exemption program for the supplier and strengthen the research system for the farming crops relate to fat and oil. It can improve the development of biodiesel which sustains stability against oxidation and keeps good mobility over the low temperatures in the winter season by new additives and develops new processes to show good harmony with diesel engine.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.6
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• pp.704-711
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• 2017

Korea, which has a high dependency on energy imports, is greatly affected by fluctuations in international oil prices. In order to offset these effects, various policies such as 'diversification of energy sources' and 'energy mix' are being pursued. Renewable Fuel Standard (RFS) is a policy promoted for this purpose, and a compulsory mixing system is applied only to the diesel. In order to reduce dependence on fossil fuels in various countries, they are concentrating on the dissemination of bio-alcohol as well as bio-diesel, and commercialization through various verification. In this study, evaluation of domestic materials and vehicles was carried out to promote domestic bio alcohol fuel. We analyzed the fuel characteristics of domestic quality standard items by mixing them with gasoline of automobile at a certain mixing ratio (0%, 3%, 6%, and 10%).