• 한국분무공학회지
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• 제26권4호
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• pp.182-188
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• 2021

In this paper, using a transfer function-based analytical model, major factors influencing the acoustics and combustion instability in a two-stage duct system composed of a nozzle and a combustor were derived and their quantitative effects were evaluated. From the acoustic analysis, it was confirmed that the change in reflection coefficient and mean flow could have a great influence on the instability growth rate, and the area ratio and speed of sound ratio between the nozzle and the combustor are also key parameters to determine combustion instability as well as flame transfer functions.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.333-335
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• 2014

As the user demand for power plants becomes various, design objective becomes complicated. To review the system feasibility, system objective and evaluation criteria need to be newly defined. In this study, engineering design procedure of the multi-purpose power plant, such as barge-mounted combined cycle power plant with $CO_2$ capture, was shown as a previous work for the feasibility review of the system alternatives. For the system design, heat and mass balance for each system configuration was firstly performed. Using the thermal analysis results, conceptual design of system alternatives was carried out. And then, preliminary design of the major equipment was done. The engineering calculation results of this study would be used as the evaluation data for system feasibility review.

• 동력기계공학회지
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• 제17권6호
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• pp.5-10
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• 2013

Diesel engines have the advantages of good fuel efficiency and low emissions. Therefore, car makers have been developed various kinds of diesel engine management system to clean up emissions while improving fuel efficiency. One of them is the common rail system. In the common rail system, diesel fuel is injected into the combustion chamber at ultra high pressures up to 1,800 bar to ensure more complete combustion for cleaner exhaust gas, and highly precise multiple injection reduces NOx emission, combustion noise and vibration. Generally speaking, common rail system consists of booster pump, high pressure pump, common rail, injectors, control valves, and sensors. The high pressure pump receives low pressure fuel from the booster pump and supply high pressure fuel to injectors through the high pressure common injection rail. Therefore, high pressure pump has an important role in common rail system. In this paper, we have investigated the performance of high pressure pump of common rail system.

• 한국산학기술학회논문지
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• 제8권1호
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• pp.1-9
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• 2007

본 연구에서는 수분 함유량이 높은 하수 슬러지 처리를 위한 열 건조기를 포함하는 100kg/hr급 소용량 사이클론 소각시스템의 소각 성능을 평가하였다. 국내에서 발생하는 하수 슬러지의 물성치를 바탕으로 소각시스템을 설계하였다. 슬러지 수분 정도, 슬러지 투입량, 보조연료량 등 동작조건의 변화에 따른 성능실험을 통하여 소각시스템의 특성을 분석하였다. 정상 운전 시 전체시스템의 압력 손실은 700mmAq로 비교적 적게 나타났으며, 소각기 내부의 연소에 의한 온도분포도 $1000^{\circ}C$미만으로 유지되었다. 수분 86.1%의 슬러지 100kg을 소각하는 경우 $4.7{\ell}/hr$ 정도의 보조 연료가 필요하다. 소각기 내부의 온도가 $1000^{\circ}C$ 미만으로 유지되기 때문에 측정된 대부분의 NOx는 연소과정에 발생된 열적인 NOx 보다는 슬러지 중에 포함된 N 성분의 산화에 의하여 발생되는 연료적 NOx인 것으로 예측된다. 배출된 소각재의 성분 분석 결과, 소각재 속에는 유기물이 전혀 검출되지 않았으며, 이로부터 소각기에서 완전 연소가 이루어진 것으로 예상된다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2009년도 춘계학술대회 논문집
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• pp.402-405
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• 2009

본 리뷰에서는 미국 DARPA가 극초음속 순항 비행체를 위하여 최근 시작한 정적연소 기반 극초음속 추진기관 개발 프로그램에 대하여 소개한다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.157-160
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• 2006

The Dish/Stirling system with the Stirling engine is currently used to convert solar energy directly to electrical energy successful operation of dish/Stirling system is supported by hybrid system, which will allow continuous operation driven by solar and combustion heat ins. The hybrid Receiver has to be provided with an additional combustion system. The heat pipe receiver and conbustion system were manufactured and tested for thermal characteristics of receiver. Maximum temperature difference along the heat pipe surface is $200^{\circ}C$. Emission measurements showed low NOx values of 28 to 46 ppm and very high CO values of 18 to 201 ppm.

• 한국정밀공학회지
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• 제22권5호
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• pp.138-143
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• 2005

Recently, automobile manufacturers regarding stability, economic environmental-friendly problems by the development of automobile, environmental problem as designing the exhaust system. Increasingly strict environmental regulations to lower fuel consumption and reduce emission. Also to reduce the noise and the vibration of the automobile. According to develop variable type muffler, dual muffler and active intelligence exhaust system unit. Improvement in engine performance and fuel consumption rate demand information of pressure fraction and heat characteristics. To be able to determine these factor for we experiment on each case of exhaust system unit. In this study, how back pressure is distributed in flow-through in exhaust system and how to design exhaust system flexibleness, efficiency and combustion charateristics influenced by back pressure. This study furnish basic data for engineers, technicians.

• 한국연소학회지
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• 제10권1호
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• pp.20-26
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• 2005

In the present study, catalytic combustion of hydrogen-air premixture in a millimeter scale monolith coated with Pt catalyst was investigated. As the combustor size decreases, the heat loss increases in proportion with the inverse of the scale of combustion chamber and combustion efficiency decreases in a conventional type of combustor. Combustion reaction assisted by catalyst can reduce the heat loss by decreasing the reaction temperature at which catalytic conversion takes place. Another advantage of catalytic combustion is that ignition is not required. Platinum was coated by incipient wetness method on a millimeter scale monolith with cell size of $1{\times}1mm$. Using this monolith as the core of the reaction chamber, temperatures were recorded at various locations along the flow direction. Burnt gas was passed to a gas chromatography system to measure the hydrogen content after the reaction. The measurements were made at various volume flow rate of the fuel-air premixture. The gas chromatography results showed the reaction was complete at all the test conditions and the reacting species penetrated the laminar boundary layer at the honeycomb and made contact with the catalyst coated surface. At all the measuring locations, the record showed monotonous increase of temperature during the measurement duration. And the temperature profile showed that the peak temperature is reached at the point nearest to the gas inlet and decreasing temperature along the flow direction.

• 한국자동차공학회논문집
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• 제12권3호
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• pp.75-82
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• 2004

The allowable exhaust standard has been intensified as a part of the countermeasure to decrease air pollution in the world. As the cars with an alternative fuel starts to get into the spotlight, the cars with low emission has been introduced and exhaust gas regulation forced in this country. These days, LPG vehicles, which infrastructure of fuel was already built up, and CNG vehicles are recognized for alternative fuel cars in this country. In this study, the constant volume combustion chamber was manufactured and used for experiments to obtain the ignition characteristics of LPG fuel and the optimal ignition energy. The experiment measured the combustion characteristics, in regard to the change of combustion variable, and the change of ignition energy. During the combustion of fuel, the maximum temperature inside the combustion chamber is higher when the initial pressure is higher. The burning velocity also seems to have the same characteristic as the temperature. However, the heat flux did not change much with the theoretical correct mixture but the various initial temperature of the combustion chamber. The heat flux got faster and ignition energy bigger as the dwell time of the ignition system expanded. When the dwell time get longer, the ignition energy also increased then fixed. The ignition energy increased as the initial pressure inside the combustion chamber higher. The heat flux got faster as the dwell time expanded.

• 한국연소학회지
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• 제8권1호
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• pp.46-56
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• 2003

The present paper is concerned with the development of the computational biology in the past half century and its relationship with combustion. The modem computational biology is considered to be initiated by the work of Alan Turing on the morphogenesis in 1952. This paper first touches the life and scientific achievement of Alan Turing and his theory on the morphogenesis based on the reactive-diffusive instability, called the Turing instability. The theory of Turing instability was later extended to the nonlinear realm of the reactive-diffusive systems, which is discussed in the framework of the excitable media by using the Oregonator model. Then, combustion analogies of the Turing instability and excitable media are discussed for the cellular instability, pattern forming combustion phenomena and flame edge. Finally, the recent efforts on numerical simulations of biological systems, employing the detailed bio-chemical knietic mechanism is discussed along with the possibility of applying the numerical combustion techniques to the computational cell biology.