• 드라이브 ㆍ 컨트롤
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• 제9권4호
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• pp.52-57
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• 2012

In this study, in order to understand contents and ranges of design for the EGR Valve test system for improving quality and performance of EGR Valve, engine performance and exhaust gas characteristic of 3L-class diesel engine was analyzed. Experimental operation of engine performance test was performed with 50% engine load and 20% and 100% opening ratio of EGR Valve. From test of performance and exhaust gas characteristic of engine, torque output of engine and temperature and pressure of inlet and outlet of EGR Valve were measured. As a result, for design of EGR Valve test system, input fluid flow of EGR Valve must be set the same amount with exhaust gas flow that was below of engine speed of 2,500 rpm, and temperature of inlet of EGR Valve must be set under about $510^{\circ}C$. And the difference of temperature between inlet and outlet of EGR Valve must be over than about $200^{\circ}C$. Exhaust gas of inlet and outlet of EGR Valve were under 1 bar that was not considerable, and the difference of pressure between inlet and outlet of EGR Valve were under 1 bar that could not effect on mechanical operation of EGR Valve.

• 한국자동차공학회논문집
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• 제19권4호
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• pp.114-120
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• 2011

Fuel reforming technology for the fuel cell vehicles has been frequently applied to internal combustion engine for the reduction of engine out emissions. Since syngas which is reformed from fossil fuel has hydrogen as a major component, it has abilities to enhance the combustion characteristics with wide flammability and high speed flame propagation. In this paper, syngas was feed to a 2.0 liter SI engine with MPI to improve exhaust emissions under cold start and early state of idle condition. Syngas fraction is varied to 0%, 10%, 25%, with various ignition timings. Exhaust emission characteristics and the exhaust system temperature were measured to investigate the effects of syngas addition on cold start. Result showed that HC emission could be dramatically reduced due to the fact that syngas has $H_2$ and no HC as components. The amount of $NO_x$ emission was decreased with the increase of syngas fraction. Because the dilution effect of $N_2$ and the retard of ignition timing reduces the peak combustion temperature inside the cylinder. Exhaust gas temperature was lower than that of gasoline feeding condition. Retarded ignition timing, however, resulted in increased exhaust gas temperature approximated to gasoline condition. It is supposed that the usage of syngas in an SI engine is an effective solution to meet the future strict emission regulations.

• 한국가스학회지
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• 제5권1호
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• pp.7-14
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• 2001

가정집 가스보일러 배기가스 조성에 대하여 열역학적 관점에서 해석하였고 일산화탄소 센서의 특성에 대하여 고찰하였다. 배기가스의 조성 측정으로부터 보일러 연소조건을 예측할 수 있음을 본 연구에서 제시하였다. 즉 배기가스중의 산소농도로부터 과잉 공기량을 예측할 수 있고, 배기가스중의 일산화탄소와 수소의 비율로부터 보일러 연소실 온도를 알 수 있다. 가정집에 설치되어 있는 보일러의 배기가스 조성 해석으로부터 과잉 공기량이 약 $55\~110\%$임을 알 수 있었다. 따라서 가정집 가스보일러에서 발생하는 일산화탄소는 연소가스의 유속구배에 의한 난류에 의한 국부냉각 또는 벽에 의한 국부냉각으로 등에 의하여 발생하는 것으로 사료된다. CO센서의 출력전압은 수소와 일산화탄소의 농도에 선형적으로 비례하며, 보일러에서 일산화탄소 발생을 CO센서와 연동제어로 감소시킬 수 있다.

• 한국자동차공학회논문집
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• 제11권3호
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• pp.39-47
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• 2003

UEGI (Unburned Exhaust Gas Ignition) is an alternative method for fast light-off of a catalyst. It ignites the unburned exhaust mixture using two glow plugs installed in the upstream of the close-coupled catalysts. In addition, a hydrocarbon adsorber was applied to the UEGI, for more effective reduction of HC emission. Engine bench tests show that the CCC reaches the light-off temperature laster than the baseline exhaust system and HC and CO emissions are reduced significantly during the cold start. From the vehicle test, it was observed that a few amount of HC emission was reduced even the catalysts were aged. It is expected to develop a solution kit applicable to a new vehicle or used one, to meet the emission regulation

• 한국자동차공학회논문집
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• 제9권2호
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• pp.43-49
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• 2001

In order to satisfy the ULEV emissions regulation, fast light-off of a catalyst is essential for reduction of HC and CO emissions during the cold start. Cranking Exhaust Gas Ignition(CEGI) method developed in this study showed that the catalyst reaches the light-off temperature in a few seconds. The CEGI stops the ignition signal for a few seconds during the cranking period, so the unburned fuel-air mixture bypasses the combustion chamber and flows through the exhaust manifold. When the unburned mixture reaches two glow plugs installed upstream of the catalyst, it burns and releases the thermal energy to heat up the catalyst, In the FTP-75 vehicle tests, the CEGI showed that the exhaust emissions reduced by 47.7% for THC and by 88.6% for CO in the cold-transient phase of the test.

• 한국자동차공학회논문집
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• 제5권4호
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• pp.130-141
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• 1997

Work on the reduction of particulate matter(PM) from a diesel vehicl has led to a new trp system and a control method to control the combustion rate of the PM filtrated in the trap, which was named as 'Active Exhaust Feeding Regeneration(AEFR) System' by its operation mechanism. Ceramic cordierite filter is a major component of the trap and susceptible to thermal shock. Therefore the system should be designed to reduce the peak temperature and temperature gradients in the trap ; these have been considered to be the main factors causing thermal shock of the filter during the regeneration. It uses the engine's exhaust gas partially for the regeneration of the ceramic filter. It controlled bypass flow rate of the engine's exhaust gas precisely to control the temperature of the gas entrained into the filter. Gas temperatures were measured inside filter, and the oxygen concentration at the outlet of the filter was also monitored during the regeneration to analyze the combustion process of the PM. The temperature distributions and temperature gradients in the filter during the regeneration varied widely according to the regeneration control schemes. Finally, this system shows relatively low peak temperature and temperature gradients in the filter during its regeneration. It is considered that this system uses a mew method to control the combustion rate of the PM, which is different from the methods used in the previous studies.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.802-806
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• 2004

For the protection of the local air quality and the global atmosphere, the emissions of trace species including nitric oxides (NO and NO$_2$) from gas turbines are regulated by local governments and by the International Civil Aviation Organization. In-situ measurements of such species are needed not only for the development of advanced low-emission combustion concepts but also for providing emissions data required for the sound assessment of the effects of the emissions on environment. We have been developing a laser absorption system that has a capability of simultaneous determination of NO and NO$_2$concentrations in the exhaust jets from aero gas turbines. A diode laser operating near 1.8 micrometer is used for the detection of NO while a separated visible tunable diode laser operating near 676 nanometers is used for NO$_2$. The sensitivities at elevated temperature conditions were determined for simulated gas mixtures heated up to 500K in a heated cell of a straight 0.5 m optical path. Sensitivity limits estimated as were 30 ppmv-m and 3.7 ppmv-m for NO and NO$_2$, respectively, at a typical exhaust gas temperature of 800K. Experiments using the simulated exhaust flows have proven that $CO_2$ and $H_2O$ vapor - both major combustion products - do not show any interference in the NO or NO$_2$ measurements. The measurement system has been applied to the NO/NO$_2$ measurements in NO and NO$_2$ doped real combustion gas jets issuing from a rectangular nozzle having 0.4 m optical path. The lower detection limits of the system were considerably decreased by using a multipass optical cell. A pair of off-axis parabola mirrors successfully suppressed the beam steering in the combustion gas jets by centralizing the fluctuating beam in sensor area of the detectors.

• 사물인터넷융복합논문지
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• 제8권1호
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• pp.23-29
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• 2022

본 연구의 개발대상 제품은 선박 및 발전용 EGB(Exhaust Gas Boiler-폐열보일러) 종류로써 디젤 엔진, 가스 엔진, 가스 터빈 등에서 나오는 배기 가스의 여열을 이용하여 물을 가열하여 고온·고압의 증기나 온수를 발생시키는 열회수 장치이다. 발생된 증기나 온수는 선박의 선실 난방 및 온수 시설이나 HFO Heating, 터빈 구동에 필요한 동력원으로 사용된다. 폐열보일러의 원리는 여열을 가진 고온의 배기 가스가 보일러의 Tube를 통과하면서 물을 데우는 역할을 한다. 데워진 물은 스팀 형태로 선실이나 터빈장치로 보내어져 사용하게 되는 구조이다. 본 연구에서는 EGB의 열전달 부품인 관형 튜브를 Plate Tube로 대체하여 열전달 표면을 늘려 효율을 극대화하는데 목표가 있다.

• 대한기계학회논문집B
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• 제37권3호
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• pp.243-248
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• 2013

내연기관은 연료로 공급되는 에너지의 30~40%만을 동력에너지로 전환되고 나머지 60~70%는 손실에너지와 배기에너지로 버려지게 된다. 따라서 배기에너지를 회수한다면 기계적 에너지 또는 전기적 에너지로 변환시킬 수 있다. 열전발전기는 배기관에 위치하여 고온 열원과 저온 열원 사이에 온도차를 이용한다. 두 열원 사이에 온도차를 이용하여 전기적 에너지를 발생시켜 동력 에너지 등 여러 에너지로 변환 가능하다. 이 논문에서는 이러한 열전발전기의 특성을 예측하기 위해 수치해석을 통하여 여러 조건에 따른 열전발전기 특성을 예측하였다. 수치해석 결과 고온 열원과 저온 열원 간의 온도 차이가 클수록 발생하는 전력 역시 증가하는 것을 알 수 있었다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
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• pp.151-152
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• 2012

Collectors connected to diesel engine exhaust pipe for application of PM reduction facilities which was used to reduce PM from the exhaust gas produced from ship, Filtration performance of PM was tested. In this system, it was confirmed that the bag house can remove over 90 percent of PM from a lot of high temperature and high pressure gases produced in diesel engine. The results obtained from performance test show the potential possibility for commercialization of ceramic filter collectors which is applied to reduction facilities of flue gas produced from a diesel engine on the ship.