• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.163-170
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• 2016

Regulations for the exhaust gas of diesel vehicles are being strengthened every year. Recently, diesel emission regulations for HC, CO, NOx, and particulate matter (PM) have been subject to very strict standards. In the future, the regulation of PM is expected to become stricter. Accordingly, diesel particulate filters (DPFs) have been applied to most diesel vehicles for PM reduction. With increasing engine mileage, ash and soot from the engine exhaust gas accumulate inside the DPF. This accumulation can damage the DPF or degrade engine performance. Therefore, efficient cleaning of the DPF is critical for the maintenance of the engine. If the DPF is well managed through regular cleaning, it can improve the power and fuel economy of the engine and reduce maintenance costs. Therefore, this study was performed to develop a high-efficiency cleaning method for DPFs and an apparatus that can more effectively clean out the accumulated ash and soot.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.1
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• pp.8-13
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• 2008

Emissions from automobiles have long been considered a prime source of pollutants involved in smog formation and ozone production. Especially VOCs are associated with serious environmental problems such as photo-chemical smog as well as human health effects. Since motor vehicles are a major source of VOCs, estimating of emission from mobile source is the most important factor to control VOCs. VOCs are emitted from various pollution like motor vehicles, mobile and stationary source that has characteristics of toxicity, cancer-causing, bio-accumulation, durability in air and diffusion can exert a bad influence upon human health and environment. However we don't have any standard or regulation about VOCs emissions. This study is summarized as VOCs emission characteristics from in-use light-duty diesel and LPG fueled vehicles. The vehicle exhaust-gas test mode is CVS cycle and nier-10 cycles that developed on EPA and National Institute of Environmental Research. TO-14 method (Toxic Organic) was chosen for VOCs analysis from EPA in USA. This study results will be useful when make a emission factor and rule making of emission standard about domestic VOCs emission for the improve to air condition.

• 한국연소학회:학술대회논문집
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• 2003.05a
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• pp.21-26
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• 2003

Diesel particulate trap is a core technology for the reduction of PM from diesel vehicles This study presents the features and the characteristics of DPF system when using pellet type filters. In comparison with wall-flow filter, the pellet filter has the advantages of cracking free during regeneration and shape flexibility. Experiments are conducted in a test bench simulated as diesel engine exhaust condition. Pressure drop and particle loading rate was compared by using two pellet filters having the porosity of 70% and 0%. Also its regeneration was tested.

• 한국연소학회:학술대회논문집
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• 2007.05a
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• pp.98-103
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• 2007

The number of vehicles employing diesel engines is rapidly rising. Accompanying this trend, application of an after-treatment system is strictly required as a result of reinforced exhaust regulations. The Diesel Particulate Filter (DPF) system is considered as the most efficient method to reduce particulate matter (PM), but the improvement of a regeneration performance at any engine operation point presents a considerable challenge by itself. Temperature, gas compostion and flow rate of exhaust gas are important parameters in DPF evaluation, especially regeneration process. Engine dynamometer and degment tester are generally used in DPF evaluation so far. But these test method couldn't reveal the effect of various parameters on real DPF, such as O2 concentration, amount of soot and exhaust gas temperature. This research has studied the possibility using dump combustor that used to take an approach lean premixed combustion in gas turbine for a DPF power and optimized. It is possible that utilize the system as DOC (Diesel Oxidation Catalyst) and SCR(Selective Catalytic Reduction) assessments test as well as DPF evaluation

• Journal of ILASS-Korea
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• v.16 no.2
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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.

• Journal of Biosystems Engineering
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• v.23 no.2
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• pp.125-134
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• 1998

It seems possible, by use of vegetable oils, to solve the pollution problem caused by the exhaust gas from diesel-engine vehicles. Recently vegetable oils has received considerable attention as an alternative and clean energy source to the foreseeable depletion of world oil supplies. The objective of this study is to experimentally investigate the characteristics of exhaust emissions of a small diesel engine using light oil, rice-bran oil, heated rice-bran oil, rice-bran oil treated with ultrasonic energy. SO$_2$ emission from the pure and the treated rice-bran oils was not detected at speeds hgher than 1,800 rpm while that from the light oil was detected at all the speeds at 4/4 load. NOx emission form these vegetable oils was generally higher compared to that from the light oil for most of the test conditions. tendency opposite to that of NOx emission. The data obtained in this experiment may be applicable for the desist of small diesel engine using the alternative fuels.

• Journal of ILASS-Korea
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• v.2 no.3
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• pp.44-50
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• 1997

Bio-diesel oil is a great possibility to solve the pollution problem caused by the exhaust gas from diesel engine vehicles. Recently the use of bio-oils in disel engines has received considerable attention to the forseeable depletion of world oil supplies. So, Bio-diesel oil has been attracted with attentions as an alternative and clean energy source. The objective of this paper is to experimentally investigate the characteristic of performance using light oil, rice-bran oil, heated rice-bran oil, rice-bran oil treated with ultrasonic energy. We included rice-bran oil and applied ultrasonic energy to highly viscous bio-oils. These methods seems to have never been tried yet. The final data may be able to be applicated for the design of the diesel engine using an alternative fuel.

• Journal of the Korean Institute of Gas
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• v.15 no.2
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• pp.21-26
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• 2011

Emissoin of heavy duty vehicle have much positioned in air pollution although its limited number of vehicles. CNG vehicles are coming to the fore as one of the solution of diesel vehicles. CNG vehicles exhaust smaller emission than diesel vehicles on PM and NOx. In this study, aftertreatment technologies are introduced on vehicles which use CNG and hydrogenmixed fuel. Withmixing hydrogen with CNG, combustion efficiency is enhanced, and harmful emission might be decreased, but methane that is main component of CNG brings green house effect. In order to remove methane and NOx in exhaust gas of CNG engine, methane oxidation catalyst and SCR technologies were respectively analyzed.

• Environmental and Resource Economics Review
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• v.32 no.2
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• pp.107-126
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• 2023

This study analyzes the financial efficiency of the early scappage support system using the benefit and cost analysis. To do so, we use comprehensive administrative data on the early scrappage of old diesel vehicles. The result shows that the benefit-cost ratio was greater than 1 before 2020, but it appeared to be less than 1 after 2020. This indicates that despite recent reforms to increase the subsidy of early scrappage of old diesel vehicles, the rate of the benefit of air quality improvement is not as fast as the increase in system operation cost of this system. The benefit of air quality improvement depends on how much the operating period is shortened due to early scrappage support system. The earlier this period is brought forward, the more likely it is that the benefits of early scrappage will exceed the costs. Upon examining the results of this study, it was found that when the scrappage timing is brought forward by 5 years, the B/C for 98% of the samples becomes 1, greatly securing financial efficiency. Therefore, it is important for the government to reform the system so that it can influence the decision of old diesel vehicle owners on the timing of scrappage.

• Journal of Sensor Science and Technology
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• v.27 no.4
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• pp.221-226
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• 2018

Misfueling accidents significantly damage the engines of both gasoline and diesel vehicles, and should be avoided by rapid and accurate fuel discrimination. Gasoline fuel contains bioethanol. Thus, the detection of ethanol vapor produced by gasoline can be used to distinguish between gasoline and diesel. In the present study, Pt-doped $SnO_2$ hollow nanospheres, Mg-doped $In_2O_3$ hollow microspheres, and Pt-doped ZnO nanostructures have been used as gas sensors to discriminate between gasoline and diesel fuels. All three sensors are able to detect and discriminate between gases evaporating from gasoline and diesel. Among the sensors, the Mg-doped $In_2O_3$ hollow microspheres show a significant gas response (resistance ratio = 4.97) quickly (~3 s) after exposure to gasoline-evaporated gas at $225^{\circ}C$, but did not show any substantial response to diesel-evaporated gas. This demonstrates that gasoline and diesel fuels can be discriminated using small and cost-effective oxide semiconductor gas sensors.