• Journal of Mechanical Science and Technology
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• 제18권7호
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• pp.1169-1176
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• 2004

Soot has a great effect on the formation of PM (Particulate Matter) in D.I. (Direct Injection) Diesel engines. Soot in diesel flame is formed by incomplete combustion when the fuel atomization and mixture formation were poor. Therefore, the understanding of soot formation in a D.I. diesel engine is mandatory to reduce PM in exhaust gas. To investigate soot formation in diesel combustion, various measurements have been performed with laser diagnostics. In this study, the relative soot diameter and the relative number density in a DJ. engine was measured by using LIS (Laser Induced Scattering) and LII (Laser Induced Incandescence) methods simultaneously which are planar imaging techniques. And a visualization D.I. diesel engine was used to introduce a laser beam into the combustion chamber and investigate the diffusion flame characteristics. To find the optimal condition that reduces soot formation in diesel combustion, various injection timing and the swirl flow in the cylinder using the SCV (Swirl Control Valve) were applied. From this experiment, the effects of injection timing and swirl on soot formation were established. Effective reduction of soot formation is possible through the control of these two factors.

• 한국산학기술학회논문지
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• 제7권3호
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• pp.278-284
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• 2006

가솔린 엔진에 비하여 디젤 엔진은 효율성, 신뢰성, 내구성 측면에서 우수한 특성을 보유하고 있다. 그러나, 디젤 엔진의 최대 약점은 카본기 물질로 알려진 분진(PM)의 방출이다. 최근 엔진 제어와 후처리를 통하여 엄격한 규제 조항에 부합하는 커다란 기술적 발전을 이룩하였다. 보다 엄격하게 진행되고 있는 환경규제를 대응하기 위하여, 본 연구에서는 배기가스 온도 증대를 통한 PM 저감 방안에 초점을 맞추었다. PM 재생 온도를 증대시키기 위하여, DPF 필터와 DOC 전방에 HC를 분사하는 방안을 제안하였다. 본 연구를 통하여, 우리는 LPG 분사 특성을 파악할 수 있는 벤치를 제작하고 관련 DB를 구축하여 LPG 분사 최적화와 ECU 제어 로직을 정량화 할 수 있었다.

• Korean Chemical Engineering Research
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• 제56권5호
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• pp.752-760
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• 2018

경유자동차에서 배출되는 탄소 입자상 물질 연소 온도구간을 낮추는 것은 미세먼지 배출 저감과 내연기관 자동차의 고연비 저배출 성능 구현이라는 측면에서 매우 중요한 기술적 과제 중 하나이다. 본 논문에서는 탄소 입자상 물질의 산화를 위해 오존을 산화제로 이용하고 백금계 산화촉매를 동시에 적용했을 때 관찰되는 $150^{\circ}C$ 부근 저온영역에서의 탄소 입자상 물질 연소반응에 관하여 논했다. 백금계 산화촉매를 적용했을 때 오존에 의한 탄소 입자상 물질의 산화속도를 크게 개선시키지 못했지만 연소반응의 이산화탄소 선택도를 향상시켰으며, 탄소 입자상 물질의 선택적 산화를 위해 고려된 NO의 $NO_2$로의 사전 전환($NO_2$-rich 조건)은 $NO_2$와 오존의 상호 상승작용에 의해 $150^{\circ}C$ 부근 온도영역에서의 탄소상 입자물질 연소성능을 높이는데 효과가 있었다.

• International Journal of Automotive Technology
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• 제3권1호
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• pp.1-8
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• 2002

There is Increasing world-wide interest in diesel particulate filters (DPF) because of their proven effectiveness in reducing exhaust smoke and particulate emissions. Fine particulates have been linked to human health . DPF use requires a means to secure the bum-out of the accumulated soot, a process called regeneration. If this is not achieved, the engine cannot continue to operate. A number of techniques are available, but most are complex, expensive or have a high electrical demand. The use of fuel additives to catalyse soot bum-out potentially solves the problem of securing regeneration reliably and at low cost. Work on organo-metallic fuel additives has shown that certain metals combine to glove exceptional regeneration performance. Best performance was achieved with a combination of iron and strontium based compounds. Tests were carried out un a bed engine and on road vehicles, which demonstrated effective and reliable regeneration from a tow dose fuel additive, using a single passive DPF. No control valves, flow diverters. heaters or other devices were employed to assist regeneration. Independent particle size measurements showed that there were no harmful side effects from the use of the iron-strontium fuel additive.

• 한국환경보건학회지
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• 제33권1호
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• pp.36-42
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• 2007

Diesel PM can be controlled using Diesel Particulate Filter, which can effectively reduce the level of soot emissions to ambient background levels. In the Heavy Duty Diesel area, the Continuously Regeneration trap has been widely applied in the retrofit market. As the Special act for the improvement of air quality in the capital area, the retrofit program for DPF to used diesel vehicle has progressed favorably and there are currently over 1,000 of these DPF in use in retrofit applications in korea. These DPF comprise a specially formulated Diesel Oxidation Catalyst upstream of a DPF. The $NO_2$ generated by the DOC is used to combust the carbon collected in the DPF at low temperature. To certificate DPF device that is suitable to domestic circumstances, it is necessary to evaluate exactly the DPF devices according to the regulation of DPF certificate test procedure for retrofit(ministry of environment(MOE) announcement NO. 2005-16). To do so the understand of that regulation like the standard of PM reduction rate is needed. In this study the test procedure including test cycle and BPT test condition was examined and also the test result for specific DPF was analyzed. In every test like field test, PM reduction efficiency test and seoul-10 mode test, no defect could be showed.

• Journal of Forest and Environmental Science
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• 제33권2호
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• pp.113-121
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• 2017

In flight particulate matter particularly emissions generated by incomplete combustion processes has become a subject of global concern due to the health problems and environmental impacts associated with them. This has compelled most countries to set standards for coarse and fine particles due to their conspicuous impacts on environment and public health. This contribution therefore explores forest fire emissions and how its particulates affects air quality, damage to vegetation, water bodies and biological functions as architects for lung diseases and other degenerative illnesses such as oxidative stress and aging. Soot was collected from simulated forest fire using a clean glass surface and carefully transferred into amber vials for analysis. Volatile components of soot were collected over 10 mL dichloromethane and analyzed using a QTOF Premier-Water Corp Liquid Chromatography hyphenated to a mass selective detector (MSD), and Gas Chromatograph coupled to a mass spectrometer (GC-MS). To characterize the size and surface morphology of soot, a scanning electron microscope (SEM) was used. The characterization of molecular volatiles from simulated forest fire emissions revealed long chain compounds including octadec-9-enoic acid, octadec-6-enoic acid, cyclotetracosane, cyclotetradecane, and a few aromatic hydrocarbons (benzene and naphthalene). Special classes of organics (dibenzo-p-dioxin and 2H-benzopyran) were also detected as minor products. Dibenzo-p-dioxin for instance in chlorinated form is one of the deadliest environmental organic toxins. The average particulate size of emissions using SEM was found to be $11.51{\pm}4.91{\mu}m$. This study has shown that most of the emissions from simulated forest fire fall within $PM_{10}$ particulate size. The molecular by-products of forest fire and particulate emissions may be toxic to both human and natural ecosystems, and are possible precursors for various respiratory ailments and cancers. The burning of a forest by natural disasters or man-made fires results in the destruction of natural habitats and serious air pollution.

• 한국자동차공학회논문집
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• 제19권3호
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• pp.52-56
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• 2011

Active regeneration in CDPF requires $O_2$ which regenerates soot at high temperature. However, small amount of NO can interrupt $O_2$ regeneration in CDPF. To verify this phenomena, soot oxidation experiments using a flow reactor with a $Pr/CeO_2$ catalyst are carried out to simulate Catalyzed Diesel Particulate Filter (CDPF) phenomena. Catalytic soot oxidation with and without small amount of NO is conducted under tight contact condition. As the heating rate rises, the temperature gap of maximum reaction rate is increased between with and without 50ppm NO. To accelerate the $NO_2$ de-coupling effect, CTO process is performed to eliminate interfacial contact for that time. As CTO process is extended, temperature which indicates peak reaction rate increases. From this result, it is found that small amount of NO can affect tight contact soot oxidation by removal of interfacial contact between soot and catalyst.

• Journal of Advanced Marine Engineering and Technology
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• 제30권1호
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• pp.88-92
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• 2006

This study is intended to check the flame temperature to raise in burning grade C heavy fuel oil and emulsion fuel oil in a boiler and to measure the concentration of Dry Shoot(DS) and Soluble Organic Fraction(SOF) after collecting the Particulate Matters (PM). The flames temperature in boiler was measured by burning grade C heavy oil and oil-water emulsion (C heavy oil $70\%\;and\;30\%$ of water) Combustion characteristics of two fuels was also compared by trapping particulate matters (PM) in exhaust gas and measuring the generated quantities of DS and SOF in fuel gas.

• 한국입자에어로졸학회지
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• 제19권4호
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• pp.101-110
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• 2023

In order to reduce particulate matters (PM) from marine diesel engines, we developed novel electrostatic diesel particulate matter filtration system. Electrostatic diesel particulate filtration (DPF) system consists of electrostatic charger and filtration part. The electrostatic charger and filtration part are composed of a metal discharge electrode and a metal fiber filter (porosity: 68.1-86.1%), respectively. In the electrostatic charger part, diesel soot particles are reduced by electrostatic force. The filtration part after electrostatic charger part reduces diesel soot particles through inertial and diffusion forces. The filtration efficiency of electrostatic DPF system was examined through the experiments using engine dynamometer system (300 kW) and ship (200 kW). The PM reduction efficiencies due to inertial and electrostatic forces showed about 70-75% and 80-90%, respectively, according to the RPM of the engine. The differential pressure of the electrostatic DPF system applied to the ship was about 1-9 mbar, which was less than the allowable differential pressure for ship engines in South Korea (100 mbar). The results show that the electrostatic DPF system is suitable for application to the PM reduction emitted from ships.

• 한국산학기술학회논문지
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• 제17권3호
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• pp.163-170
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• 2016

디젤 자동차의 배기가스 규제는 매년 지속적으로 강화되고 있다. 최근 HC, CO, NOx, PM에 대한 배기 규제는 매우 엄격한 기준을 적용하고 있다. 향후에는, 입자상 물질의 수량규제로 더욱 강화될 것으로 예상되고 있다. 이에 따라, 현재 대부분의 디젤 차량은 PM 저감을 위해 배기후처리징치(DPF)를 적용해 왔다. 엔진의 주행거리가 증가함에 따라, 엔진 배기가스에 포함된 재와 soot이 DPF내부에 축적된다. 축적된 재와 soot은 DPF 손상이나 엔진 성능 악화의 원인이 된다. 그러므로 효율적인 DPF의 클리닝은 엔진관리 측면에서 매우 중요한 부분이다. 만약 엔진이 주기적 클리닝을 통해 관리가 잘 된다면 엔진의 출력과 연비를 개선하고, 유지관리 비용을 절감할 수 있다. 따라서, 본 연구에서는 DPF 내부에 누적된 재와 soot을 효과적으로 클리닝 할 수 있는 고효율 DPF 클리닝 방법 및 장치의 개발을 수행하였고, 그 결과를 제시하였다.