• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.534-537
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• 2009

최근 자동차 배기가스 규제가 더욱 강화됨에 따라 완전 연소를 통한 배기가스 저감에 관하여 많은 연구가 진행되고 있다. 특히, 고온 연소시 문제가 되는 질소 산화물의 저감을 위해 많은 노력을 기울이고 있다. 질소 산화물을 저감하는데 효과적인 EGR 기술의 도입이 보편화되고 있지만, 각 실린더별 EGR 분배 특성에 따라 엔진의 성능이 달라지는 역효과가 발생한다. 시제품을 동한 EGR 분배특성 파악은 비용과 시간 측면에서 상당한 난제가 산재해있다. 본 연구에서는 이러한 실험시간과 비용 절감을 위하여 1D 성능해석 프로그램인 GT-Power를 적용 EGR의 분배특성을 예측하였다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.2 no.S1
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• pp.75-75
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• 1996

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2006.05a
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• pp.405-411
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• 2006

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.543-545
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• 2009

유럽을 포함한 많은 선진국들은 자동차 배기가스에 대한 환경규제를 만족하기 위해서 노력을 하고 있다. 가솔린 엔진에 비해서 문제가 되는 디젤엔진에서 배출되는 배기가스 즉 질소 산화물과 입자상 물질을 저감하려는 노력은 꾸준히 진행되고 있다. 본 논문은 11,000cc 대형 터보 디젤엔진에 배기가스 순환장치를 설치하여 질소산화물을 효과적으로 저감하는 기술을 개발하고자한다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.10
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• pp.637-644
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• 2016

The purpose of this study is to understand the characteristics of unburned carbon (UBC) and NOx emissions for pulverized coal when air staging combustion is applied. A two-staged drop tube furnace capable of applying air staging combustion was designed and installed. The combustion of sub-bituminous (Tanito) has been investigated. UBC and the NOx concentration were measured under various temperatures and stoichiometric ratios in unstaged and staged combustion. As a result, UBC decreased and the NOx concentration increased with an increase in stoichiometric ratio and temperature. In particular, the NOx reduction mechanism was activated when the temperature in the fuel rich zone increased. Both UBC and the NOx concentration decreased as the temperature increased in the fuel rich zone. A high NOx reduction effect was obtained, compared to the UBC increase, when the air staging technique was applied.

• Ecology and Resilient Infrastructure
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• v.11 no.2
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• pp.23-34
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• 2024

Sediment, aquifer materials, surface water, and groundwater from brackish Songji lake affected by salinity of seawater, were collected and a pilot scale column experiment was conducted to simulate the nitrogen transport through the hyporheic zone. Upstream experiments of groundwater displayed that groundwater containing a small amount of salt percolated into aquifers and sediments, maintaining low dissolved oxygen concentrations. In addition, partial denitrification occurred in the aquifer due to salinity and low dissolved oxygen, resulting in the accumulation of NO₂^-. In sediments,nitrogenous compounds were reduced due to adsorption by long residence times or microbial-mediated oxidation/reduction reactions. Downstream experiments of surface water displayed that surface water from the brackish lake, containing high concentrations of dissolved oxygen and salts, infiltrated into the sediments and aquifer, supplying high dissolved oxygen concentrations. This resulted in biological nitrification in the sediments and aquifer, which reduced nitrogen-based pollutants despite the high salt concentration in the surface water. Whereas partial denitrification at low dissolved oxygen concentrations in the upwelling mixing zone was observed by salinity and accumulated NO₂^-, nitrification at high dissolved oxygen concentrations in the downwelling mixing zone was not significantly affected by salinity. These results confirm that salinity in the brackish water lake has some influence on the nitrogen behavior of the hyporheic mixing zone, although nitrogen behavior is a complex combination of factors such as DO, pH, substrate concentration, and organic matter concentration.

• Journal of the Korean Society of Marine Environment & Safety
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• v.2 no.S1
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• pp.77-85
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• 1996

As conservation of global environment has becoming a major outstanding issue of the world, the International Maritime Organization(IMO) has been legislation a convention for prevention of air pollution from ships. By the new convention, use of air pollutants such SOx, NOx, Freon and Halin Gas shall be restricted. In this regards, analysing these requirements of the convention is required as the cinvention will also be applied in restriction of descharging exhaust gases from ships by estsblishing a requirement of Sox and NOx discharged. The purpose of this study is as follows; 1) Introdcuing of the backgrounds of legislating the convention for prevention of air pollution from ships and major contents of the convention and a countermeasuures in the convention by Korea 2) Reviewing by analyzing the influence in domestic industries concernd by restriction of SOx, NOx in exhaust gases and sulpher content of fuel oil 3) Preparing a countermeasure in the convention properly.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.2
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• pp.69-69
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• 1996

As conservation of global environment has becoming a major outstanding issue of the world, the International Maritime Organization(IMO) has been legislation a convention for prevention of air pollution from ships. By the new convention, use of air pollutants such as SOx, NOx, Freon and Halon Gas shall be restricted. In this regards, analysing these requirements of the convention is required as the convention will also be applied on restriction of discharging exhaust gases from ships by establishing a requirement of SOx and NOx discharged. The purposed of this study is as follows ; 1) Introducing of the backgrounds of legislating the convention for prevention of air pollution from ships and major contents of the convention and a countermeasures on the convention by Korea. 2) Reviewing by analyzing the influence on domestic industies concerned by restriction of SOx, NOx in exhaust gases and sulphur content of fuel oil. 3) Preparing a countermeasure on the convention properly.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.2
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• pp.1-6
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• 1996

As conservation of global environment has becoming a major outstanding issue of the world, the International Maritime Organization(IMO) has been legislation a convention for prevention of air pollution from ships. By the new convention, use of air pollutants such as SO/sub x/, NO/sub x/, Freon and Halon Gas shall be restricted. In this regards, analysing these requirements of the convention is required as the convention will also be applied on restriction of discharging exhaust gases from ships by establishing a requirement of SO/sub x/ and NO/sub x/ discharged. The purposed of this study is as follows ; 1) Introducing of the backgrounds of legislating the convention for prevention of air pollution from ships and major contents of the convention and a countermeasures on the convention by Korea. 2) Reviewing by analyzing the influence on domestic industies concerned by restriction of SO/sub x/, NO/sub x/ in exhaust gases and sulphur content of fuel oil. 3) Preparing a countermeasure on the convention properly.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.5
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• pp.31-38
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• 2009

Supercharging system was adopted to investigate the influence of boost pressure on operating range and exhaust emissions by using a supercharger at low temperature diesel combustion (LTC) condition in a 5-cylinder 2.7 L direct injection diesel engine. The experimental parameters such as injection quantity, injection timing, injection pressure and exhaust gas recirculation (EGR) rate were varied to find maximum operating range in LTC condition. As a result of adopting increased boost pressure in LTC, wider operating range was achieved compared with naturally aspirated condition due to increased mixing intensity. Increased boost pressure resulted in lower hydrocarbon (HC) and carbon monoxide (CO) emissions due to increased swirl rate and mixing intensity, which induced complete combustion. Moreover, increased boost pressure in LTC resulted in much lower soot emissions compared with high speed direct injection (HSDI) condition.