• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.449-452
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• 2004

“Flameless combustion” of lean to ultra lean mixtures, supported by high-temperature burned gas, can resolve the dilemma between complete combustion versus ultra-low NOx emissions in gas turbine combustors. The characteristics of NOx emissions and combustion in “lean-lean” two-stage combustion were investigated for fuel vapor and droplets / air mixture jets injected from the main injection tube that was placed perpendicular to the combustor wall into the primary hot burned gas prepared by combustion of lean mixtures on a perforated flame holder. The present results clearly show that the ultra-low NOx combustion supported by the reaction of lean mixtures well mixed with the hot burned gas from the primary stage is much more advantageous in achieving ultra-low NOx emissions while maintaining high combustion efficiency.

• 한국연소학회지
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• 제3권1호
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• pp.49-57
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• 1998

High temperature preheated and diluted air combustion has been developed as the technology to realize higher thermal efficiency. In this type of combustion, there are many interesting phenomena which cannot be observed in room temperature air combustion. The characteristics of the combustion, investigated using a 3500 kcal/h LPG fired test facility, are described. The flame is demonstrated to have a blue and green in color and has a large volume. As the preheated air temperature increased up to $1000\;^{\circ}C$, the NOx emission incrased exponentially over a few hundred ppm with 11% $O_2$ correction. But, it drastically reducedabout 20ppm when the air was diluted from 21% $O_2$ to 5% $O_2$.

• 한국자동차공학회논문집
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• 제22권2호
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• pp.83-90
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• 2014

The main purpose of the study is to investigate the ideal manner and ratio to inject gasoline and DME simultaneously into intake port, and moreover to confirm the characteristics of combustion and emission of engine. Experimental conditions are 1200 rpm, compression ratio 8.5, intake air temperature (383 K). Internal cylinder pressure was collected to confirm the characteristics of combustion in order to calculate the heat release rate in the cylinder. In addition, HORIBA (MEXA 7100) which was possible analyzing emissions (NOx, CO, HC) was used. Vanguard gasoline engine (23HP386447) was used in this experiment. The result show that fuel design (DME-Gasoline) leads to the decrease of low temperature heat release, which is a benefit for higher-load on the HCCI engine. Also, IMEP and the indicated thermal efficiency increase with combustion-phasing retard, and these observations can be explained by considering the control of low temperature oxidation of DME.

• 한국연소학회지
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• 제8권1호
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• pp.17-24
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• 2003

The conventional regenerative system has a high thermal efficiency as well as energy saving using the high preheated combustion air. in spite of these advantages, it can not avoid high nitric oxide emissions. Recently, flameless combustion has received much attention to solve these problems. In this research, numerical analysis is performed for flow-combustion phenomena in the self regenerative burner. In this analysis we used Fluent 6.0 code. the that is developed for commercial use, Methane gas is used as a fuel and two-step reaction model for methane and Zeldovich mechanism for NO generation are used. the velocity of the preheated combustion air is used as a parameter and we analyze the characteristics of flow-field, temperature distributions and NO emissions. Due to the increased recirculation rate, the maximum temperature of flame is significantly increased and NOx emissions is reduced.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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• pp.183-186
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• 2012

The characteristics of particulate matters (PM) from an exhaust gas for conventional and low temperature diesel combustion (LTC) in a compression ignition engine was experimentally investigated by the elemental, thermogravimetric analysis. Morphology of PM was also studied by the transmission electron microscopy. PM for LTC shows that it contains more volatile hydrocarbons, which can be easily evaporated than conventional regime. PM for LTC is comprised of smaller primary particles.

• 한국자동차공학회논문집
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• 제19권6호
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• pp.17-22
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• 2011

This study is to investigate the effect of the cetane number in ultra low sulfur diesel fuel on combustion characteristics and exhaust emissions at 1500 rpm and 2.6bar BMEP in low-temperature diesel combustion with 1.9L common rail direct injection diesel engine. Low-temperature diesel combustion was achieved by adopting external high EGR rate with the strategic injection control without modification of engine components. Test fuels are ultra low sulfur diesel fuel (sulfur less than 12 ppm) with two cetane numbers (CN), i.e., CN30 and CN55. For the CN30 fuel, as a start of injection (SOI) timing is retarded, the duration of an ignition delay was decreased while still longer than $20^{\circ}CA$ for all the SOI timings. In the meanwhile, the CN55 fuel showed that an ignition delay was monotonically extended as an SOI timing is retarded but much shorter than that of the CN30 fuel. The duration of combustion for both fuels was increased as an SOI timing is retarded. For the SOI timing for the minimum BSFC, the CN30 produced nearly zero PM much less than the CN55, while keeping the level of NOx and the fuel consumption similar to the CN55 fuel. However, the CN30 produced more THC and CO than the CN55 fuel, which may come from the longer ignition delay of CN30 to make fuel and air over-mixed.

• 한국안전학회지
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• 제10권4호
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• pp.75-80
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• 1995

Spontaneous ignition characteristics of rice cracker were observed by preforming experiments at constant ambient temperature. As the results of the experiments, the critical spontaneous ignition temperature were exponentially decreased with the increase of ambient temperature. Type of combustion of rice cracker are smouldering combustion at low ignition temperature and flame combustion at high temperature. The rice cracker containing pam oil showed lower spontaneous ignition temperature than pure rice cracker because of oxidation heat of pam oil.

• 한국연소학회지
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• 제21권4호
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• pp.39-47
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• 2016

The aims of this research were to investigate combustion characteristics of lab-scale pressurized oxy-fuel combustion(POFC) system. In this study, the reactor, 800 mm long, was equipped with co-axial burner. Low calorific value syngas that is composed of mainly CO and $H_2$ was used as fuel whereas pure oxygen was used as an oxidant. Thermal heat input to the reactor varied from 2.6 kW to 6.1 kW. The reactor pressure also increases from atmospheric up to 15 bar. The results show that as the pressure increase, the temperature of reactor decreases on the whole in all cases. A significant temperature drop was observed especially at the bottom section of the reactor that exist flame. In addition, the flame instability increases as the pressure increases. Furthermore $NO_x$ emissions increases from atmospheric up to 2 bar. However beyond 2 bar, $NO_x$ emission reduces as pressure increases. Lastly $NO_2$ ratio in $NO_x$ also increases as pressure increases.

• 한국화재소방학회논문지
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• 제15권2호
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• pp.1-5
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• 2001

전분 분말의 온도에 따른 열적 안정성을 조사하기 위하여 시차주사열량계(DSC, Differential Scanning Calorimeter) 빛 열중량 분석기(TGA, Thermogravimetric Analysis)를 이용하여 온도에 따른 발열개시 온도, 발열량 등을 조사하였으며, 자연발화 시험기를 이용하여 시료량에 따른 전분 분말의 연소특성을 시간에 따른 온도의 변화를 측정하여 연소개시시간 및 연소시 상승하는 온도를 측정함과 동시에 육안으로 연소특성을 조사하고자 하였다. 한편 자연발화 시험기 내부의 공기흐름에 따른 연소특성을 조사하기 위하여 송풍과 무풍 상태에서의 연소특성을 조사하고자 하였다. 선분 분말의 열분석 결과 승온속도가 증가할 수록 발열개시온도가 저온부로 이동하고 있으며, 발열량도 크게 증가하였다. 또한, 자연발화 실험결과 전분의 양이 증가할수록 훈소 개시온도가 낮아지고, 연소형태는 모두 훈소였다. 자연발화 시험기 내부가 송풍상태일 때 보다 무풍상태로 실험하였을 경우 훈소 개시시간이 다소 빨라지고 있으며, 발열최고온도도 크게 나타났다.

• Journal of Advanced Marine Engineering and Technology
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• 제36권6호
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• pp.774-779
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• 2012

MILD(Moderate and Intense Low Oxygen Dilution) 연소는 연소 가스의 재순환을 이용하여 고온 형성을 최대한 억제하고 질소산화물의 발생을 저감하는 동시에 연소로의 내부 온도 균일화를 통한 열 이용 효율을 향상시킬 수 있는 연소기술이다. 본 연구에서는 원추형 연소로에서 연료 유량은 고정하고 공기 유량으로 당량비(${\Phi}$)를 조절하고 배기가스를 측정하여 MILD 연소특성을 도출하였다.