• 한국수소및신에너지학회논문집
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• 제24권5호
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• pp.428-436
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• 2013

Attrition characteristics of $CO_2$ absorbents for pre-combustion $CO_2$ capture were investigated to check attrition loss of those absorbents and to determine solid circulation direction and the better $CO_2$ absorbent. The cumulative attrition losses of two absorbents increased with increasing time. However, attrition loss under a humidified condition was lower than that under a non-humidified condition case. Between two absorbents, attrition loss of PKM1-SU absorbent was higher than that of P4-600 absorbent. The average particle sizes of the attrited particles were less than $2.5{\mu}m$ for two absorbents under a non-humidified condition case, and therefore, we could conclude that the main mechanism of attrition for two absorbents is not fragmentation but abrasion. Based on the results from the test for the effect of humidity on the attrition loss, we selected solid circulation direction from SEWGS reactor to regeneration reactor because the SEWGS reactor contains more water vapor than regeneration reactor. Attrition loss and make-up rate of two absorbents were compared based on the results from $CO_2$ sorption capacity tests and attrition tests. Required make-up rate of P4-600 absorbent was lower than that of PKM1-SU absorbent. However, more detail investigation on the optimum regeneration temperature, manufacturing cost, solid circulation rate, regeneration rate, and long-term sorption capacity should be considered to select the best $CO_2$ absorbent.

• 연구논문집
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• 통권29호
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• pp.29-38
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• 1999

In comparison with gasoline engine, LPG direct injection engine has some advantages not only in emission and fuel efficiency but also in prevention of power decrease and back fire etc. which are disadvantages of conventional LPG engine. In this study, comparision tests of the incylinder spray and combustion characteristics between of LPG and gasoline fuels were performed in the RCEM as a basic research for the development of future LPG engine with low emission and high fuel efficiency During the direct injection of LPG fuel and gasoline into the inside of RCEM, spray development characteristics according to the injection condition have been photographed by the high speed shadow graph methods. The conditions for the optimum mixture distribution of LPG and gasoline fuels are achievable at the selected ignition timing, respectively.

• 오토저널
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• 제14권4호
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• pp.31-38
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• 1992

The objective of this study is to determine the ignition feasibility of a single shot, air-assisted gasoline fuel injector operated in a constant volume combustion chamber under atmospheric condition. A number of parameters has been selected for this experiments, such as dwelling time, spark gap position(r,z), spark electrode geometry, supplied air and fuel masses and spray cone deflector angle. On-site visual inspection of the instantaneous flame glow was chosen as one way to judge the successful ignition. In addition, chamber pressure and occasional photography were mobilized as for data recording. It was clearly observed that there was an entrainment air-fuel mixture toward spray axis from the spray formation and its development later on. The optimum ignition conditions were found for those parameters given above.

• 한국해양공학회지
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• 제14권2호
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• pp.60-64
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• 2000

An experimental study was performed to investigate the optimal ejector and operating condition of vessel incinerator. Exhaust gas temperature and secondary air which makes vacuum pressure at ejector throat regions were considered as an important factor. According to the measurement of pressure temperature and nitrogen oxides between non combustion and combustion we found the stream and exhaust gas characteristics of incinerator. This results can give us the exhaust gas temperature control system air pollutant reduction method and the optimum ejector design.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.668-673
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• 2000

Spud angle( ${\alpha}$ ) and fuel injection angle ( ${\beta}$ ) have strong influence on spud type gas burner combustion. A wide range of flame stability is shown at ${\alpha}=60^{\circ}$, but at ${\alpha}=30^{\circ}$ is narrow. Optimum condition of flame stability swirl angle( ${\gamma}$ ) is $40^{\circ}$. At condition of ${\alpha}=30^{\circ}$ flame shape is relatively narrow and long, on the other hand, at ${\alpha}=60^{\circ}$ flame is wide and short. Regardless of spud angle, maximum flame temperature shows in the range of Z=200mm and R=0mm. Flame temperature, on the whole, is high at ${\alpha}=45^{\circ}$. At ${\alpha}=45^{\circ}$, NOx emission is higher than other conditions that may be concerned with flame temperature. At ${\beta}=60^{\circ}$ and ${\gamma}=40^{\circ}$, NOx emission is reduced due to fuel injection angle.

• 대한기계학회논문집B
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• 제25권2호
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• pp.235-243
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• 2001

This paper describes a design study of the cylindrical multi-hole premixed burner to be used for condensing gas boiler which can raise performance and reduce NOx emission. In this study, specifications of the multi-hole burner (hole diameters and arrangement) are investigated using model flat burners in terms of flame stability, and combustion characteristics for stability and NOx emission are examined for cylindrical multi-hole burner. As a result, the equivalence ratio for optimum operation condition of the cylindrical burner is around 0.72(0.7∼0.75). In this condition, turn-down ratio becomes 3 : 1 at least which is suitable for proportional control. The NOx and CO emission is less than 40ppm and 25ppm(0$_2$0% basis), respectively. This burner can be applied LPG as well as NG because there is no difference for stable combustion region.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제28회 춘계학술대회논문집
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• pp.13-16
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• 2007

반파장 공명기가 장착된 연소실의 비선형 음향 감쇠를 알아보기 위하여 비선형 음향해석을 수행하였다. 먼저 공명기가 없는 기본 연소실에 80 dB에서 150 dB의 넓은 범위의 음향파를 가진하여 음향장을 분석하였다. 제 1 접선방향 음향 모드의 감쇠율은 가진되는 음향파의 크기에 따라 비선형적으로 증가하였고, 125 dB 이상부터 비선형성이 나타나기 시작했다. 다음으로 반파장 공명기의 감쇠 효과를 조사하였다. 선형해석으로부터 유도된 최적의 음향학적인 동조 조건이 비선형 음향해석에서도 여전히 유효함을 알 수 있었다. 큰 음향파의 섭동에 대한 감쇠는 효과적이지만, 선형 음향 가진에 비해서 음향학적인 감쇠기로써의 기능은 작아짐을 알 수 있었다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2009년도 춘계학술대회 논문집
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• pp.281-284
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• 2009

로켓엔진 연소기의 연소 불안정 억제를 위해 연소 상황에서의 1/4파장 공명기의 주파수 동조를 수치적으로 연구하였다. 상온 음향 시험을 통해 도출된 최적 감쇠 조건을 충족시키는 사양의 1/4파장 공명기를 채택하였다. 먼저, 실규모 연소실의 조건을 모사한 모형 연소실에서의 연소장을 수치해석하여 기본 음향파 응답 특성을 분석하였다. 다음으로, 이 연소실에 음향 공명기를 장착하여 공명기 내부 물성치를 예측하였다. 이러한 기본 데이터를 토대로 특정 음향 모드를 감쇠시킬 수 있는 주파수 동조 방안을 연구하였다. 각 공명기 내부의 물성치를 토대로 공명기를 개별 공명기의 최적 동조 길이로 설계할 경우에 충분한 감쇠 성능을 얻을 수 있었다. 설계의 편의를 위해 모든 공명기를 동일길이로 설정한 경우, 길이에 따른 감쇠성능을 비교하여 제시하였다. 이를 토대로 최적의 동조길이를 찾을 수 있었다.

• 한국자동차공학회논문집
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• 제1권3호
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• pp.12-21
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• 1993

In recent years, high efficiency, high performance, and low pollutant emmision engines have been developed. Knock phenomenon has drawn interests because it became an hinderance to engine power and efficiency increase through higher compression ratio. Knock phenomenon is an abnormal combustion originated from autoignition of unburned gas in the end-gas region during the later stage of combustion process and accompanied a high pitched metallic noise. And this phenomenon is characterized by knock occurrence percentage, knock occurrence angle and knock intensity. A four cylinder spark ignition engine is used in our experiment, and its combustion chamber pressure is measured at various engine speeds, ignition timing. The data are analyzed by numerous methods in order to select the optimum methods and to achieve better understanding of knock characteristics. Methods using band-pass filter, third derivative and step method are shown to be the most suitable, while methods using frequency analysis are shown to be unsuitable. Because step method only uses signals above threshold value during knocking condition, pressure signal analyses with this method show good signal-to-noise ratio.

• Journal of Advanced Marine Engineering and Technology
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• 제36권5호
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• pp.603-608
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• 2012

요즈음 환경오염 문제와 대체에너지 문제에 관심이 증대되고 있다. 디젤기관은 일반적으로 육상과 해상에서 동력을 생산하는데 사용되고 있는데, 디젤기관의 연소특성과 배기배출물 특성은 기관의 운전시간이 증가함에 따라 연료계통의 마모와 연소실 주위상태의 변화로 달라진다. 본 논문은 약 20여년 사용한 디젤기관에 바이오디젤혼합유를 사용할 경우, 연소특성과 배기배출물 특성에 미치는 연료분사시기의 영향을 고찰하기 위하여 실험적으로 연구하였다. 실험기관의 원래 연료분사시기는 BTDC $22^{\circ}$ CA이었는데, 20여년 운전한 후에 연료소비율과 배기배출물 특성에 대하여 실험적으로 최적의 연료분사시기를 분석한 결과, BTDC $26^{\circ}$ CA로 변경되었음을 알았다.