• 대한기계학회논문집B
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• 제27권8호
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• pp.1191-1199
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• 2003

This paper describes to observe the combustion process of only one droplet cluster. In this study, liquid fuel was atomized by ultrasonic wave to form an acoustically levitated droplet cluster. In order to elucidate the detailed structure of burning process of the droplet cluster, laser tomography method was applied. Time-series planar images of fuel droplets were processed and diameter of the each droplet was calculated based on the Mie-scattering theory. Using these data, the modified droplet group combustion number was estimated in time-series. As the result, when the internal droplet group combustion occur, the modified group combustion number dose not decrease monotonically, but show a tow-staged decreasing process. In all case of combustion process, combustion reactions were measured two types that combustion speed was fast and slow. It was casued by difference of concentration degree and droplet size distribution.

• 대한기계학회논문집
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• 제8권3호
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• pp.201-209
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• 1984

본 연구는 Kim과 Chiu가 사용한 연속체 관점에서 유도된 액체-기체상의 2상유 동모델(Two Phase Flow:TPF)을 이용하여 초기 집단연소수(group combustion number)의 크기, 즉 액적들의 초기 분포상태에 따른 연소상태를 예측 분류한다. 또한 이때 예 측된 대표적인 연소상태에서 형성되는 화염의 성질을 비교 검토한다.

• 한국수소및신에너지학회논문집
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• 제28권6호
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• pp.721-728
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• 2017

In this work, an one-dimensional analysis on spontaneous combustion in a coal stockpile was conducted using a commercial software $gPROMS^{(R)}$ based on assumption suggested by Arioy and Akgun. According to them, it is assumed that there is temperature difference between the surface of coal particle and the gas surrounded around the particle, and it is also assumed that the velocity of the gas is constant and thus oxygen is fed to the stockpile with same velocity. The higher temperature zone is formed to the surface of the coal stockpile at the initial phase and it became deepen as time is taken. Finally it was found that the temperature difference between coal particle and the gas was calculated as $57^{\circ}C$ and spontaneous combustion have not been occurred during 6 months since coal was piled in the stock.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2008년도 춘계학술 발표회
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• pp.61-64
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• 2008

• 대한환경공학회지
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• 제31권6호
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• pp.442-448
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• 2009

예혼합 분무화염의 유적군 연소 기구를 평가하기 위하여 레이저 가시화법, MICRO (multi-color integrated Cassegrain receiving optics) 및 PDA (phase Doppler anemometer) 광학계측 시스템을 이용하여 동시 시계열 계측을 실시하였다. 또한 유적군의 군연소수를 실험적으로 산출하여 이론해석에 적용하였을 경우 실제로 관찰되는 군연소 형태와 일치하는지에 대하여 검토하였다. 유적군 단면화상에 의해 확인된 모든 유적군에 대하여 실험적으로 군연소수 $G_c$를 산출한 결과 주로 내부 군연소와 외부 군연소로 분류되었으며 이론해석과 일치하였다. 또한 실제 관찰된 군연소 형태와 그 유적군의 군연소수를 이론해석에 적용한 경우에 군연소 형태가 일치하는 경우와 일치하지 않는 경우가 있었다. 일치하지 않는 원인은 군연소수를 유적의 기하학적 배치만으로 결정한 것이나 현상의 3차원성이 측정 결과에 영향을 미친 것이라고 생각되어진다.

• 에너지공학
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• 제23권4호
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• pp.207-214
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• 2014

고급탄의 고갈에 따라 석탄화력발전소에서의 저급탄 혼소가 필수불가결하게 되었다. 본 연구에서는 국내에서 수입되는 석탄 중에서 대표적으로 사용되는 역청탄과 아역청탄에 대한 연소특성을 0.7MWth 파일롯 연소실험장치를 사용하여 측정, 분석하였다. 과잉공기비가 1.2인 상태에서 축방향 및 반경방향의 노내 가스온도 및 주요 가스농도를 측정하였으며, 역청탄 연소시 반응로 내의 입자 샘플링을 수행하였다. 두 탄종의 주반응영역은 노 상부의 스월버너로부터 약 1m 근방에서 형성되었으며, 노 하류에서는 완전 확립된 온도와 농도분포를 나타내었다. 포집된 역청탄의 고체입자 분석으로부터 주반응영역 이후에 완전한 탄소전환이 이루어진 것을 확인하였다.

• 한국연소학회:학술대회논문집
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• 대한연소학회 2003년도 제27회 KOSCO SYMPOSIUM 논문집
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• pp.309-328
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• 2003

Catalytic combustion is the cleanest emissions technology that has been demonstrated for the gas turbine. It has been a primary part of the research portfolio for the Combustor and Heat Transfer Technology Group at Cranfield University since 1989. The Paper describes the background to studies in the Group, their evolution and presents some results for specific study areas and themes.

• 대한기계학회논문집
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• 제8권6호
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• pp.544-552
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• 1984

본 연구에서는 Chiu et al.의 집단연소이론에 대한 비정상집단연소모델(non- steady group combustion model)을 개발, 정지된 액적군에서 초기 액적들의 분포상태, 즉 초기액적들의 크기, 수밀도 및 액적군의 크기에 따른 연소시간, 연소형태 및 특성 과 화염의 성질등을 비정상 상태하에서 이론적인 모델을 통하여 고찰한다.

• 동력기계공학회지
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• 제12권5호
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• pp.14-19
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• 2008

In order to meet stringent future emission regulations, especially to reduce Particulate Matter (PM) and NOX, stoichiometric diesel combustion technology with a piezo group-hole nozzle injector is being researched for reduction harmful emissions. A new nozzle layout, namely a group-hole nozzle, which has one group of small orifices with a wide spray included angle was investigated to improve the efficiency of stoichiometric diesel combustion. From this point of view, the group-hole nozzle suggested by Dense Co. is an attractive candidate method applicable to stoichiometric diesel combustion. The group-hole nozzle concept is to reduce the injector nozzle hole diameters without sacrificing spray penetration by closely locating two holes. Experimental studies have proven that the spray from group-hole nozzles have similar spray penetration to that of a single hole with equivalent overall nozzle hole area, but the spray drop sizes (SMD) are reduced, aiding vaporization and mixing.

• The Korean Journal of Ceramics
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• 제6권1호
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• pp.47-52
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• 2000

Lanthanides such as La, Gd and Ce have recognized as elements of high level radioactive wastes immobilized by forming solid solution with $CaTiO_3$. For easy forming solid solution between $CaTiO_3$and lanthanides, the combustion synthesis process was applied and the powder characteristics and sinterability were investigated. The proper selection of the type and the composition of fuels are important to get the crystalline solid solution of $CaTiO_3$and lanthanides. When glycine or the mixtures of urea and citric acid with stoichiometric composition was used as a fuel, the solid solution of $CaTiO_3$with $La_2O_3$or $Gd_2O_3$or $CeO_2$was produced very well by the combustion process. The combustion synthesized powder seemed to have a good sinterability with the linear shrinkage of more than 25% up to $1500^{\circ}C$, while that of the solid state reacted powder was less than 10% at the same condition.