• Journal of Korean Society for Atmospheric Environment
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• v.29 no.6
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• pp.745-756
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• 2013

The purpose of this study is to evaluate representativeness of fuel-based emission factors. Twelve light-duty diesel vehicles which meet Euro-3 to 5 legislative emission limits were selected for emission tests. Second-by-second modal emission rates of vehicles were measured on a standard laboratory chassis dynamometer system. An off-cycle driving cycle was developed as a representative Korean real-world on-road driving cycle. Fuel-based emission factors were developed for short trip segments that involved in the selected driving cycle. Each segment was defined to have unit travel distance, which is 1 km, and characterized by its average speed and Relative Positive Acceleration (RPA). Fuel-based $NO_x$ emission factors demonstrate relatively good representativeness in terms of vehicle operation conditions. $NO_x$ emission factors are estimated to be within ${\pm}20%$ of area-wide emission factor under more than 40% of total driving situations. This result implies that the fuel-based $NO_x$ emission factor could be practically implemented into the on-road emission management strategies, such as a remote sensing device (RSD). High emitting vehicles as well as high emitting operating conditions heavily affect on the mean values and distributions of CO and THC emission factors. Few high emitting conditions are pulling up the mean value and biasing the distributions, which weaken representativeness of fuel-based CO and THC emission factors.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.5
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• pp.97-106
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• 2009

An objective of this study is to give practical information that could be used for calculating pollutant emission factors and fuel economy from Korean Inspection & Maintenance program, which has been using steady state acceleration simulation mode. Concentration results from I/M test is adequately converted to mass emission factors and fuel efficiency data, which have unit of g/km and km/L, respectively. Exhaust volume flow(EVF), which is for converting emission result from concentration to mass, is measured by tracer method in various vehicle speed - power condition. It is found that there is an apparent second order relationship between EVF and vehicle inertia weight. EVF is expressed in function of vehicle inertia weight in order to estimate EVF in I/M site without measuring device. Converted mass emission results from measured EVF and raw emission analyzer show a satisfactory agreement with those from conventional CVS-bag type measurement system. Mass emission factors and fuel efficiency from measured EVF and estimated EVF also show good agreement to each other. Considering that an I/M program has great advantages to recruit-based emission test in terms of the number of test vehicle, the information in this study can be used for developing an alternative procedure to collect more various data to establish national database of mobile emission factors and fuel economy, even though the driving cycle in I/M program is steady state cycle rather than transient cycle.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.4
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• pp.351-360
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• 2017

In this study, we developed emission factors from solid-fuel fired combustors. In order to increase the reliability of emission factors, we conducted a joint research with the Institute of Health and Environment. As a result, PM average concentration was $8.19mg/m^3$. $SO_2$ and $NO_x$ were respectively 8.46 ppm, 50.64 ppm. Hazardous air pollutants such as Cr, Pb and Hg were detected in trace amounts continuously for 2 years in some solid-fuel fired combustors. The emission factors for the three kinds of PM, $SO_x$, $NO_x$ were developed based on the measurement data. For the PM emission factors, that of SRF was 15.93 g/kg and that of Bio-SRF was 14.18 g/kg. Compared with those of US. EPA, emission factors of this study showed the results of low values. $SO_x$ emission factors were 4.42 g/kg for SRF and 1.39 g/kg for Bio-SRF. $NO_x$ emission factors were 13.21 g/kg and 4.43 g/kg, respectively. Through the results of this study, we would support atmospheric administration policies such as the emission factor notification revision.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.4
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• pp.539-553
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• 2004

Up to the present time, many methods to estimate emissions from a particular diesel engines have wholly depended on the quantity of diesel fuel consumed. Then, the recommended emission factors were normalized by fuel consumption, and further total activity was estimated by the total fuel consumed. One of main purposes in the study is newly to develop emission factors for the railroad diesel rolling stock (RDRS) and to estimate a total amount of major gaseous pollutants from the RDRS in Korea. Prior to develop a Korean mode emission factor. the emission factor from the USEPA was simply applied for comparative studies. When applying the USEPA emission factors, total exhaust emissions from the RDRS in Korea were estimated by 28,117tons of NOx, 2,832.3tons of CO, and 1,237.5tons of HC, etc in 2001. In this study, a emission factor for the RDRS, so called the KoRail mode (the Korean Railroad mode) has been developed on the basis of analyzing the driving pattern of the Gyeongbu-Line especially for the line-haul mode. Explicitly to make the site specific emission factors, many uncertainty problems concerning weighting factors for each power mode, limited emission test, incomplete data for RDRS, and other important input parameters were extensively examined. Total exhaust emissions by KoRail mode in Korea were estimated by 10,960tons of NOx, and 4,622tons of CO, and so on in the year of 2001. The emissions estimated by the USEPA mode were 2.6 times higher for NOx, and 1.6 times lower for CO than those by the KoRail mode. As a conclusion, based on the emission calculated from both the USEPA mode and the KoRail mode, the RDRS is considered as one of the significant mobile sources for major gaseous pollutants and thus management plans an(1 control strategies for the RDRS must be established to improve air quality near future in Korea.

• Journal of Korean Society of Transportation
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• v.33 no.5
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• pp.449-460
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• 2015

The reliability of air quality evaluation results for green transportation could be improved by applying correct emission factors. Unlike previous studies, which estimated emission factors that focused on vehicles in laboratory experiments, this study investigates emission factors according to road types and time using real driving data. The real driving data was collected using a Portable Activity Monitoring System (PAMS) according to road types and time, which it compared and analyzed fuel consumption from collected data. The result of the study shows that fuel consumption on national highway is 17.33% higher than the fuel consumption on expressway. In addition, the average fuel consumption of peak time is 4.7% higher than that of non-peak time for 22.5km/h. The difference in fuel consumption for road types and time is verified using ANOCOVA and MANOVA. As a result, the hypothesis of this study - that fuel consumption differs according to road types and time, even if the travel speed is the same - has proved valid. It also suggests correction factor of emission factors by using the difference in fuel consumption. It is highly expected that this study can improve the reliability of emissions from mobile pollution sources.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.4
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• pp.405-415
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• 2011

The objective of this study was to compare greenhouse gas emissions from road transportation by calculation methods (Tier 1, Teir 2, and Tier 3). Tier 1 based on 2006 IPCC guidelines default emission factor and amount of fuel consumption. The Tier 2 approach is the same as Tier 1 except that country-specific carbon contents of the fuel sold in road transport are used. Tier 2 based on emission factor of guidelines for local government greenhouse gas inventories (Korea Environment Corporation), the fuel consumption per one vehicle, and the registered motor vehicles. The Tier 3 approach requires detailed, country-specific data to generate activity-based emission factors for vehicle subcategories (National Institute of Environmental Research) and may involve national models. Tier 3 calculates emissions by multiplying emission factors by vehicle activity levels (e.g., VKT) for each vehicle subcategory and possible road type. VKT was estimated by using GIS road map and traffic volume of the section. The GHG average emission rate by the Tier 1 was 728,857 $tonCO_2eq$/yr, while Tier 2 and Tier 3 were 864,757 $tonCO_2eq$/yr and 661,710 $tonCO_2eq$/yr, respectively. Tier 3 was underestimated by 10.1 and 20.7 percent for the GHG emission observed by Tier 1 and Tier 2, respectively. Based on this study, we conclude that Tier 2 is reasonable GHG emissions than Tier 1 or Tier 3. But, further study is still needed to accurate GHG emission from Tier 3 method by expanding the traffic survey area and developing the model of local road traffic.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.4
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• pp.332-337
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• 2013

National investment was performed in the research and development of renewable energy because of climate change by air pollution, exhaustion of energy sources, energy security, and so on. Biodiesel fuel of the renewable energy is highlighted as friendly environment energy, it is possible to operate in regular diesel engines when it is blended with invariable ratios without making any changes. Emission factors have been estimated for commercial ship from various research institutes; however, it is difficult to develop emission factors for military vessels. In this work, biodiesel blended fuel emission factors for sulfur dioxide and carbon dioxide were quantitatively estimated from propulsive diesel engine installed on naval vessel using fuel property analysis. In addition, exhaust emissions were quantitatively calculated on the basis of fuel consumption rate with biodiesel content by percentage.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.6
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• pp.613-623
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• 2016

In this study, pilot experiments were conducted by setting operation conditions to analyze characteristics of emission for air pollutant from small two-stroke engines. Emission factors of the measured concentration of pollutant were compared with EEA. Emission factor of CO analyzed by experiments - concentration, flow rate, fuel consumption, etc.- was estimated at 816,011 g-CO/ton-fuel in average. It was confirmed that more than 80% of the fuel consumption is discharged to the Carbon Monoxide, and that as the engine load becomes higher, emission factor of CO increases in the form of log function. The average emission factor of $NO_x$ and $PM_{10}$ was $3,801g-NO_x/ton-fuel$ and $3,730g-PM_{10}/ton-fue$l each. The deviation was not large by comparing the fuel-based emission factor of EEA and the result of this study. Since considerable pollutants are expected to be discharged from the small two-stroke engines, continuous research and support of the policy is required.

• International Journal of Automotive Technology
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• v.4 no.2
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• pp.101-108
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• 2003

There are a lot of factors that influence automotive fuel economy such as average trip time per kilometer, average trip speed, the number of times of vehicle stationary, and so forth. These factors depend on road conditions and traffic environment. In this study, various driving data were measured and recorded during road tests in Seoul. The accumulated road test mileage is around 1,300 kilometers. The objective of the study is to identify the driving patterns of the Seoul metropolitan area and to analyze the fuel economy based on these driving patterns. The driving data which was acquired through road tests was analysed statistically in order to obtain the driving characteristics via modal analysis, speed analysis, and speed-acceleration analysis. Moreover, the driving data was analyzed by multivariate statistical techniques including correlation analysis, principal component analysis, and multiple linear regression analysis in order to obtain the relationships between influencing factors on fuel economy. The analyzed results show that the average speed is around 29.2 km/h, and the average fuel economy is 10.23 km/L. The vehicle speed of the Seoul metropolitan area is slower, and the stop-and-go operation is more frequent than FTP-75 test mode which is used for emission and fuel economy tests. The average trip time per kilometer is one of the most important factors in fuel consumption, and the increase of the average speed is desirable for reducing emissions and fuel consumption.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.6
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• pp.788-793
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• 2012

This study was focused on the estimations of air pollutants, such as PM(Particulate matters), SOx(Sulfur Oxides), $CO_2$(Carbon diOxides) and NOx(Nitrogen Oxides), from a diesel propulsion engine installed on a naval vessel. Legislative and regulatory actions for exhaust emissions from ships are being strengthened in international communities and national governments to protect human health and the environment. In this context, various technologies have been developed from all of the nations of the world to meet strict standards. These regulations are based on commercial ship applications and according to size, but are not suitable for military naval vessels, which have much different engine operating conditions and hull architectures. Additionally, there is no international emission control system for military ships. Emission factors have been updated for commercial ship types from work at various research institutes; however, it is difficult to develop emission factors for military vessels because of their characteristics. In this paper, exhaust emissions from diesel engines installed on naval vessels under steady navigation condition were estimated with emission inventory methodology applied to ocean going vessels using fuel-based methods and fuel sulfur content analysis.