• 제어로봇시스템학회논문지
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• 제12권11호
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• pp.1119-1123
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• 2006

The flame image processing and analysis system has been investigated for the optimal pulverized coal firing of thermal power plant, especially for lower nitrogen oxide generation and more safe operation. We aimed at gaining the relationship between burner flame image information and emissions of nitrogen oxide and unburned carbon in furnace utilizing the flame image processing methods, by which we quantitatively determine the condition of combustion on the individual humors. Its feasibility test was undertaken with a pilot furnace for coal firing, through which the system was observed to be effective for the monitoring of the combustion condition of pulverized coal firing boilers.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.301-304
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• 2015

With the experiment observation of single particle combustion, this model is built for the numerical analysis of the process. It's about the single coal particle combustion process under different conditions with reasonable assumptions. The model can express the mass, radius, density, temperature changing with different particle sizes, oxygen concentration and gas temperature. It also includes the flame sizes change in different condition and the diffusion of each species. The result shows the characters of the combustion.

• 대한기계학회논문집B
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• 제21권6호
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• pp.822-829
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• 1997

A catalytic burner was studied which can be used as a heater operated in medium temperature. Noble metal catalysts (Pd/NiO) were used, which were supported on alumina wash coated honeycomb. The maximum heat-resisting temperature of the catalyst is about 900.deg. C. Combustion efficiency of the catalytic burner reached more than 99.5 % at the excess air ratio above 1.25.NOx emissions were lower than 1.0 ppm at all operation conditions. The operation condition for a stable catalytic combustion was obtained. It was dependent on the catalyst thickness. The 30 mm thick catalyst showed the widest stable catalytic combustion region. Stable catalytic combustion region of 30 mm thick catalyst was the operation condition of excess air ratio 1.25 - 1.75 and heat flux 7 - 14 kcal/h center dot cm$^{2}$.

• 한국자동차공학회논문집
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• 제7권5호
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• pp.66-72
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• 1999

It is necessary to discuss lightening engine parts and reducing the friction of sliding parts to improve fuel consumption and combustion stability at idling condition. Lean best torque combustion which produce maximum power at a lean air-fuel ratio is effective for the reduction of exhaust gas emission and the improvement of fuel consumption. Accordingly, this study deals with the expansion of lean combustible limitation, the combustion stability and the reduction of idle speed through the analysis of combustion characteristics on the base of the control technique of precise air-fuel ratio because it does not need to maximum power at idling condition. The idle speed is increased proportional to ISC(Idle Speed Control) duty ratio. On the other hand the idle speed decreased by lean air-fuel ratio. The COV in engine speed is stable within maximum two percent up to 17.6 mixture ratio by the control of ISC duty ratio.

• 한국분무공학회지
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• 제14권4호
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• pp.163-170
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• 2009

The present study has numerically investigates the vaporization, auto-ignition and combustion processes in the high-pressure and high-temperature conditions encountered in the diesel engine. In the present study, in order to understand the overall spray combustion characteristics of DME fuel as well as to identify the distinctive differences of DME combustion processes compared to conventional hydrocarbon liquid fuels, the sequence of the comparative analysis has been systematically made for DME and n-Heptane liquid fuels. Computations for DME fuel are made for two cases including constant fuel mass flow rate condition and fixed heat release rate. Based on numerical results, the discussions are made for the detailed combustion processes of DME and n-Heptane spray.

• 동력기계공학회지
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• 제21권1호
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• pp.63-69
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• 2017

The combustion characteristics of gasoline and diesel were tested in a compression ignition engine. Both fuels were used with same common rail injection system. Combustion experiment showed that low load condition of 0.45 MPa IMEP (indicated mean effective pressure) was tested in metal and optical engines. The gasoline combustion showed higher hydrocarbon and carbon monoxide emissions but lower soot emission compared with diesel combustion. NOx emissions were very high at late injection timing but significantly decreased at early injection timing due to the lean combustion resulted from vigorous mixing process. Direct combustion visualization showed that the diesel combustion was dominated by diffusion combustion exhibiting soot incandescence and the gasoline combustion was mostly consisted of premixed combustion showing blue chemiluminescence.

• 한국환경보건학회지
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• 제26권3호
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• pp.81-85
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• 2000

In order to reduce emission of air pollutants from spot incineration, it is required to develope the combustion chamber of small wastes incinerator having combustion efficiency. The characteristics of combustion of the incinerator with combustion chamber having tangential angels with surface of 45$^{\circ}$of air supply nozzles were studied in accordance with non-grate, fixed-grate and shaking-grate in the combustion chamber. Combustion conditions were evaluated with combustion efficiency, emission of hazardous gases, temperatures, ignition loss of ash and so on. Combustion efficiencies were shown 73.9% for non-gate, 81.1% for fixed-grate and 89.0% for shaking-grate. Emissions of CO were revealed 6.52 ppm for non-grate, 273 ppm for fixed-grate and 224 for shaking-grate. Comprehensively evaluated, combustion conditions got better in order of shaking-grate, fixed-grate and non-grate. This study suggests that small wastes incinerator should have shaking-or fixed-grate in combustion chamber to get better combustion condition even though at expensive cost of manufacturing.

• 공업화학
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• 제20권6호
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• pp.675-680
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• 2009

SM탄(인도네시아산)을 이용하여 NOx 배출 특성을 조사하였다. 실험은 석탄 거치 후 승온하며 연소하는 방법과 승온 후 석탄을 주입하는 방법을 이용하였다. 산소희박 분위기에서는 배출 NOx가 연소온도와 반비례의 관계를 나타내었으며 이는 fuel N이 강한 환원 분위기에서 $N_{2}$로 전화되기 때문인 것으로 나타났다. 또한 주입 가스량 증가 시에는 산화 분위기에 의해 fuel N이 NO로 산화되어 total fuel NO가 증가하는 경향을 나타내었다. 제조 온도에 따른 char의 연소시 발생되는 NO의 분석으로 total fuel N, volatile-N, char-N이 각각 NO로 전화되는 부분으로 구분될 수 있었으며 실험결과 본 연구에 사용된 SM탄은 total NOx의 대부분이 volatile-N에 기인하는 것으로 나타났다.

• 한국자동차공학회논문집
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• 제8권4호
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• pp.26-33
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• 2000

In-cylinde flow and mixture formation are key contributors to both idle stability and combustion stability at part load condition in SI engine. The real time measurements of air-fuel ration and in- cylinder residual gas fraction are particularly important to obtain a better understanding of the mechanisms for combustion and emissions especially during cold start and throttle transient condition. This paper reports the cycle resolved measurements of residual gas fraction and equivalence ration near speak plug with value timing change and their effects on combustion characteristics at part load. The results showed that the effect of intake value opening on the residual gas fraction was smaller than that of exhaust valve closing because of the decreases of exhaust gas reverse flow from exhaust port. The variation of equivalence ratio near spark plug increased with the increase of value overlap and it closely related with heat release rate and combustion stability

• 한국연소학회지
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• 제11권2호
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• pp.28-36
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• 2006

A constant volume combustion chamber was used to investigate the combustion characteristics. of homogeneous charge of methane-air mixture under various initial pressure, equivalence ratio and ignition times. The constant volume combustion chamber(CVCC) mostly has been studied by the experiments of visualization until now. So it is needed the numerical analysis of fluid and combustion characteristics in chamber by the more detail simulation. In this paper, the numerical analysis is tried to approach basically the homogeneous charge combustion phenomena under the various conditions, and the combustion phenomena in chamber is numerically analyzed by the commercial FIRE code. As a results, the combustion phenomena which were mean temperature, OH radical and reaction rate in chamber were investigated and it showed that the smallest flame growth occurs for the lean state and the increase of initial charged pressure condition due to the reduced OH radical.