• Title/Summary/Keyword: Diesel NOx

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An Evaluation of Emission Characteristics and Fuel Consumption on the Off-road Diesel Engine using VGT and EGR (Off-road용 디젤엔진에서의 VGT 및 EGR 적용에 따른 엔진 배기 및 연비 특성 평가)

  • Ha, Hyeongsoo;Shin, Jaesik;Jung, Haksup;Pyo, Sukang;Kang, Jungho
    • Journal of the Korean Society of Combustion
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    • v.21 no.2
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    • pp.1-6
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    • 2016
  • To meet the Tier-4 emission standard, a variety of combustion technology in the field of off-road engine has been applied in conjunction with the engine after treatment technology. In this study, as the basis study for applying VGT and HPL EGR to 3.6 L CRDi engine, exhaust gas characteristics and fuel economy characteristics are confirmed in accordance with VGT and EGR operating conditions. Consequently, in the EGR applicable conditions, 60% VGT vane duty condition was confirmed that the trade-off characteristics between NOx and smoke are advantageous. In addition, in view of BSFC, VGT vane duty is considered desirable to control at around 50%.

Development of Gasoline Engine Renewal CNG Generator and a Study on Exhaust Gas Characteristics of Equivalent Diesel Engine (가솔린 엔진개조 CNG 발전기 개발과 동급 디젤엔진의 배출가스 특성 연구)

  • Lee, Jung-Cheon;Kim, Ki-Ho;Lee, Jung-Min;Park, An-Young
    • Journal of Power System Engineering
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    • v.22 no.6
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    • pp.74-79
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    • 2018
  • Compressed natural gas has a high octane number and low particulate emission characteristics as compared with petroleum-based fuels, so it can respond to exhaust gas regulations positively. A natural gas engine has been introduced to improve the quality of the atmosphere, a diversity of fuel, a stable supply, and it has widely been used in city buses and garbage trucks. Recently, the natural gas engine has received attention by overcoming the disadvantage of the theoretical air-fuel ratio method through the development of EGR cooler and engine parts with the development of LP-EGR technology. In this study, we try to develop the cogeneration system that can simultaneously generate electric power and heat by remodeling the gasoline engine to the mixer type CNG engine. As a result, it was able to reduce the NOx (approximately 77%) compared to the diesel engines with same displacement.

Structural Safety Evaluation of a 3-way Damper Valve for Scrubber-linked Exhaust Gas Control (스크러버 연계 배기가스 배출제어용 3방향 댐퍼밸브의 구조 안전성 평가)

  • Kim, Young-Hun
    • Journal of the Korean Society of Industry Convergence
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    • v.23 no.6_2
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    • pp.1007-1014
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    • 2020
  • IMO(International Maritime Organization) continues to strengthen environmental regulations on exhaust gases such as CO2, NOx, SOx. As for sulfur oxides, from 1 January 2020, all ships on international voyages must use fuel with a sulfur content of 0.5% or less. Or, it is obligatory to use an exhaust gas treatment device that has the same effect. Shipping companies are using low-sulfur oil, replacing them with LNG fuel, or installing scrubbers that suppress sulfur oxide emissions. In the case of ships using bunker C oil, the load on the engine is lower when entering and departing, so the exhaust gas pressure is lowered and the scrubber cannot be properly utilized. Therefore, diesel oil with low sulfur content is used when entering and leaving the coast. When diesel oil is used, exhaust gas is directly discharged through the control system and piping system, and when bunker C oil is used, sulfur oxides are reduced by scrubbers through other control systems and piping systems to discharge exhaust gas. Accordingly, a company has developed a system called a three-way damper valve that can control exhaust gas emissions while integrating these two control systems and piping systems into one. In this study, the control characteristics of the integrated exhaust gas control system and structural safety against external loads in a high-temperature exhaust gas environment were reviewed.

Comparison of emission characteristics between fuel injection systems with echanical cam and electric control type on low speed 2 stroke diesel engine for ship propulsion (선박추진용 기계적 캠 구동식 및 전자제어식 연료분사 시스템을 가진 저속 2행정 디젤엔진의 배기특성 비교)

  • Lee, Sang Deuk;Koh, Dae Kwon;Jung, Suk Ho
    • Journal of Advanced Marine Engineering and Technology
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    • v.37 no.6
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    • pp.611-616
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    • 2013
  • Many researches have been carried out consistently for the green ship owing to its economic increasement, efficiency and convenience. One of them is an electronic controlled marine diesel engine. However, we are suffered from dissemination of above engine, due to its anxiety about safety and reliability. In order to solve these problems in this study, emission characteristics test of main propulsive two-stroke diesel engine, equipped both electronic control and cam drive fuel injection systems, has been performed and evaluated under the various load conditions. From the test results, we have confirmed that exhaust gas emission characteristics of the electronic control system is similar to the cam drive system in eco-mode operation, but NOx in emission mode has been decreased 100ppm or more in full load condition. HC emission from the electronic control system is decreased 10~20ppm at 50% load, and 35~40ppm at 25% load in comparison to cam drive system. In fuel consumption, it is considered that 7g/kWh is decreased than the value of cam drive system at 700bar of injection pressure, which is 200bar higher than cam drive system.

Numerical Investigation of the Spray Behavior and Flow Characteristics of Urea-Water Solution Injected into Diesel Exhaust Pipe (디젤 배기관에 분사된 우레아 수용액의 분무 거동 및 유동 특성에 관한 연구)

  • An, Tae Hyun;Kim, Man Young
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.38 no.1
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    • pp.41-48
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    • 2014
  • A urea-SCR system suffers from some issues associated with the ammonia slip phenomenon, which mainly occurs because of the shortage of evaporation and thermolysis time, and this makes it difficult to achieve an uniform distribution of injected urea. A numerical study was therefore performed by changing such various parameters as installed injector angle and application and angle of mixer to enhance evaporation and the mixing of urea water solution with exhaust gases. As a result, various parameters were found to affect the evaporation and mixing characteristics between exhaust gas and urea water solution, and their optimization is required. Finally, useful guidelines were suggested to achieve the optimum design of a urea-SCR injection system for improving the DeNOx performance and reducing ammonia slip.

Numerical Analysis of Effect of Inhomogeneous Pre-mixture on Pressure Rise Rate in HCCI Engine by Using Multizone Chemical Kinetics (화학반응수치해석을 이용한 HCCI기관의 예혼합기의 성층화성이 연소시의 압력 상승률에 미치는 영향)

  • Lim, Ock-Taeck
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.5
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    • pp.449-456
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    • 2010
  • The HCCI engine is a prospective internal combustion engine with which high diesel-like efficiencies and very low NOx and particulate emissions can be achieved. However, several technical issues must be resolved before HCCI engines can be used for different applications. One of the issues concerning the HCCI engine is that the operating range of this engine is limited by the rapid pressure rise caused by the release of excessive heat. This heat release is because of the self-accelerated combustion reaction occurring in the engine and the resulting engine knock in the high-load region. The purpose of this study is to evaluate the role of thermal stratification and fuel stratification in reducing the pressure rise rate in an HCCI engine. The concentrations of NOx and CO in the exhaust gas are also evaluated to confirm combustion completeness and NOx emission. The computation is carried out with the help of a multizone code, by using the information on the detailed chemical kinetics and the effect of thermal and fuel stratification on the onset of ignition and rate of combustion. The engine is fueled with dimethyl ether (DME), which allows heat release to occur in two stages, as opposed to methane, which allows for heat release in a single stage.

An Experimental Study of Fuel Economy and Emission Characteristics for a Heavy-Duty DME Bus (대형 DME버스의 연비 및 배기가스 특성에 관한 연구)

  • Oh, Yong-Il;Pyo, Young-Duk;Kwon, Ock-Bae;Beak, Young-Sun;Cho, Sang-Hyun;Lim, Ock-Taeck
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.36 no.4
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    • pp.371-376
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    • 2012
  • The experimental test was conducted for a heavy-duty DME bus in JE-05 exhaust gas test mode using a chassis dynamometer, exhaust gas analyzers, and a PM measurement system. The heavy-duty DME bus was not equipped with after-treatment systems such as DOC or DPF. The dynamic behavior, emission characteristics, and fuel economy of the bus were investigated with an 8.0-liter, 6-cylinder conventional diesel engine. The results showed that the dynamic behavior in DME mode was almost the same as in diesel mode. However, there was little difference among the two operation modes for $NO_x$ and CO emissions. THC emissions were lower for DME mode than for diesel mode. Also, the amount of PM emissions was remarkably lower than for the diesel mode because DME contains a greater amount of oxygen than diesel. The data showed that $CO_2$ emissions were almost similar in the two modes but fuel economy (calculated using heating value) was lower for DME mode than for diesel mode.

Prediction of Nitric Oxide Formation Using a Two-Zone Model in a DI Diesel Engine (2영역 모델을 이용한 EGR사용 직접분사식 디젤엔진의 Nox생성예측)

  • Kim, Cheol-Hwan;Lee, Jin-Ho;Chun, Kwang-Min;Lee, Kyo-Seung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.3
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    • pp.390-401
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    • 2000
  • In this study, numerical calculation is carried out to investigate the influence of injection timing, fuel amount, intake $O_2$ concentration, and EGR on Nitric Oxide(NO) formation using a two-zone model in a diesel engine. Results can be summarized as follows. The NO formation is very sensitive to the burned gas temperature, so multi-zone model must be applied to combustion process to predict the burned gas temperature exactly. Since the burned gas temperature increases rapidly during the premixed combustion, most NO is formed within 20 crank angle degrees after ignition. As the injection timing is retarded, the combustion occurs later in the expansion process which causes the decrease of burned gas temperature and, as a result, NO formation decrease. The increase of fuel amount results in the increase of earlier formation of NO in the engine. As the intake $O_2$ concentration increases, the maximum pressure and burned gas temperature increase due to activate combustion. And, [O] mole fraction of equilibrium combustion products also increase. Therefore NO exponentially increases. If exhaust gas is recirculated, the burned gas temperature decreases which results in NO decrease. If exhaust gas is cooled, more NO can be decreased.

Combustion Characteristics of Biodiesel Fuel (바이오 디젤 연료의 연소특성)

  • Yoon, Seung-Hyun;Park, Sung-Wook;Kwon, Sang-Il;Lee, Chang-Sik
    • 한국연소학회:학술대회논문집
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    • 2004.11a
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    • pp.146-151
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    • 2004
  • The characteristics of combustion and emission of biodiesel fuel were investigated in a single cylinder DI diesel engine equipped with a common rail injection system. For investigating the effect of bio diesels, the experiments were conducted at various mixing ratio and engine operation conditions. Experimental results show that combustion pressure increased with the increase of mixing ratio and injection pressure. The HC and CO emissions are decreased and NOx emission is increased as the mixing ratio of biodiesels increases at 100MPa injection pressure. However the results of the emissions are shown the contrary to the results at 50MPa of injection pressure due to larger droplets of biodiesel sprays.

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Characterization of Particulate Matters and Estimation of Emission Rates Exhausted from Diesel Locomotive Engines (디젤기관차 엔진에서 배출되는 대기오염물질의 특성 및 배출량 추정)

  • 박덕신;정우성;김동술
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.05b
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    • pp.109-110
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    • 2003
  • 우리나라에서의 철도는 도로교통에 비해 수송분담율이 상대적으로 낮지만, 2001년을 기준으로 1년 동안 824만 명을 수송하여 전체 여객 수송량의 약 6.2 %를 차지하고 있다. 최근 연구결과 비도로용으로 사용되고 있는 디젤엔진이 NOx와 입자상 오염물질 배출의 주요한 오염원으로 밝혀졌다. 국내외적으로 대기오염원 중 자동차나 트럭 등 도로용 차량에서 배출되는 오염물질에 대해서는 오래 전부터 관심을 기울여 왔지만, 디젤기관차, 선박 및 경작, 건설, 벌목, 채굴 장비 등을 포함하는 비도로용 이동오염원에 의한 오염물질 배출제어에 관해서는 논의가 거의 이루어진 적이 없었다. (중략)

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