• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.295-296
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• 2015

We presented the methods calculating the reduction efficiency of nitrogen oxide for the low $NO_x$ burner as the pollution prevention facilities. The standard $NO_x$ concentration was used on the emission factor of LNG, $3.7g/m^3$. The $NO_x$ reduction efficiency based on the $NO_x$ concentration was presented and the relationships between the $NO_x$ concentration and the emission factor or the specific heat emission factor were derived. These results could be accurately reflected on calculating the amount of the nitrogen oxide emissions. In addition, according to the arrangement of the low $NO_x$ burners the methods of applying their $NO_x$ reduction efficiency were proposed. The $NO_x$ reduction efficiency for the facilities consisting of the low $NO_x$ burners and the non-low $NO_x$ burners could be estimated with information about the reduction efficiency of each low $NO_x$ burners, the fuel consumption rate, and the heating value of fuel.

• 산업기술연구
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• 제21권A호
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• pp.279-284
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• 2001

In this study, we analyzed the $NO_X$ removal effiency by the low temperature plasma process and investigated the effect of several process variables. Most of NO is converted into $NO_2$ and, later, into $HNO_3$ which reacts with $NH_3$ to form $NH_4NO_3$ particles. As the frequency of appling voltage increases, as the applied voltage increases or as the residential time increases, removal efficiency of the NO supplied initially increase. The removal efficiency of $NO_X$ also increases with the increase of $NH_3$ supplied.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.66-70
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• 2001

The combustion characteristics have been investigated to develop the low $NO_{x}$ gas turbine combustor. The lean premixed combustion technology was applied to reduce the $NO_{x}$ emission. Also, the conventional combustor was designed and tested for the baseline of low $NO_{x}$ combustor performance. The test was conducted at the condition of high temperature and ambient pressure. The combustion air which has the temperature of 500K were supplied to the combustor through the air preheater. The temperature and emissions of $NO_{x}$ and CO were measured at the exit of combustor. The premixing chamber can be operated very lean condition of equivalence ratio around 0.35. The $NO_{x}$ was decreased with decreasing the equivalence ration. The CO was decreased with decreasing the equivalence ratio, but the CO was increased with decreasing the equivalence ratio below 0.45. But, at the very lean condition of equivalence ratio below 0.35 both NOx and CO were increased because of the flame unstability. The $NO_{x}$ was decreased slightly and CO was increased with increasing inlet air flowrate. This results can be used to determine the size of combustor. The low $NO_{x}$ combustor has lower values of $NO_{x}$ and CO compared with conventional one. Consequently the performance of combustor shows the possibility of the application to the gas turbine system.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.878-883
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• 2001

The effects of external excitation with various frequencies and amplitudes on the flame behavior and pollution emission characteristics from a laminar jet flame are experimentally investigated. Measurements of $NO_{x}$ emission indices($EINO_{x}$), performed in unconformed and vertical lifted flame at resonance frequency by strong excitation, have been conducted experimentally. It was also conducted to investigate the effects of excited frequency on $NO_{x}$ emissions with a various frequency ranged 0Hz to 2kHz. From the vertical lifted flame like turbulent of the excited jet with resonance frequency was shown that the dependence of $NO_{x}$ emission could be categorized into three groups: Group 1 of intermediate flame length and relative narrow flame volume yielding low $NO_{x}$ emission, Group 2 of short flame length but large flame volume yielding high $NO_{x}$ emission and Group 3 of long flame length with low temperature contours yielding high $NO_{x}$ emission.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1499-1504
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• 2004

Flue gas recirculation (FGR) is a method used to control oxides of nitrogen ($NO_x$) in combustion system. The recirculated flue gases resulted in slow reaction and low flame temperatures, which in turn resulted in decreased thermal NO production. Recently, it has been demonstrated that introducing the recirculated flue gas in the fuel stream, that is, the fuel induced recirculation (FIR), resulted in a much greater reduction in $NO_x$ per unit mass of recirculated gas, as compared to introducing the flue gases in air. In the present study, the effect on $NO_x$ reduction in turbulent swirl flame in laboratory scale using FGR/FIR methods through the dilution using $N_2$ and $CO_2$. Results. show the $CO_2$ dilution is more effective $NO_x$ reduction methods because of large temperature drop due to the larger specific heat $CO_2$ compared to $N_2$. FIR is more effective to reduce $NO_x$ emission than FGR when the same recirculation ratio of dilution gas.

• 한국자동차공학회논문집
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• 제17권4호
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• pp.79-85
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• 2009

Low temperature combustion regime for the simultaneous reduction of nitrogen oxides ($NO_x$) and paticulate matter (PM) is demonstrated in single cylinder engine at various operating parameters, such as EGR rate, injection timing, EGR temperature, amount of fuel and swirl rate. Low temperature combustion is accomplished by high exhaust gas recirculation (EGR) rate in this study. Generally, the emission of $NO_x$ almost completely disappears and PM significantly increases in the first decreasing regime of oxygen concentration but after peaking about 10~12% oxygen concentration, PM then decreases regardless of fuel injection quantity. Low temperature combustion regime was extended by low EGR temperature, high injection pressure and low amount of fuel.

• 대한기계학회논문집B
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• 제28권3호
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• pp.359-364
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• 2004

For the development of high efficiency and low emission combustion systems, high temperature air combustion technology has been tested by utilizing preheated air over 1100 K and exhaust gas recirculation. In this system, combustion air is diluted with large amount of recirculated exhaust gases, such that the oxygen concentration is relatively low in the reaction zone, leading to low flame temperature. Since, the temperature fluctuations and sound emissions from the flame are small and flame luminosity is low, the combustion mode is expected to be flameless or mild combustion. Experiment was performed to investigate the turbulent flame structure and NO$_x$ emission characteristics in the high temperature air combustion focused on coflowing jet diffusion flames which has a fundamental structure of many practical combustion systems. The effect of turbulence has also been evaluated by installing perforated plate in the oxidizer inlet nozzle. LPG was used as a fuel. Results showed that even though NO$_x$ emission is sensitive to the combustion air temperature, the present high temperature air combustion system produce low NO$_x$ emission because it is operated in low oxygen concentration condition by the high exhaust gas recirculation.

• 한국연소학회지
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• 제20권2호
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• pp.40-45
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• 2015

This study is aimed to study combustion characteristics of low $NO_X$ burner using petroleum cokes as fuel. The petroleum coke, which is produced through the oil refining process, is an attractive fuel in terms of its high heating value and relatively low price. But petroleum coke is a challenging fuel because of its low volatile content, high sulfur and nitrogen content, which give rise to undesirable emission characteristics and low ignitability. The petroleum cokes burner is operated at fuel rich condition, and overfire air are supplied to achieve fuel lean condition. The low $NO_X$ burner is designed to control fuel and air mixing to achieve air staged combustion, in addition secondary and tertiary air are supplied through swirler. Air distribution ratio of triple staged air are optimized experimentally. The result showed that $NO_X$ concentration is lowest when overfire air is used, and the burner function at a fuel rich condition.

• 한국연소학회:학술대회논문집
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• 대한연소학회 2003년도 제27회 KOSCO SYMPOSIUM 논문집
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• pp.89-94
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• 2003

For the development of high efficiency and low emission combustion systems, high temperature air combustion technology has been tested by utilizing preheated air over 1100 K and exhaust gas recirculation. In this system, combustion air is diluted with large amount of exhaust gases ($N_2$, $CO_2$), such that the oxygen concentration is relatively low in the reaction zone, leading to low flame temperature. Since, the temperature fluctuations and sound emissions form the flame are small and flame luminosity is low, the combustion mode is expected to be flameless or mild combustion. Experiment was performed to investigate the turbulent flame structure and $NO_X$ emission characteristics in the high temperature air combustion focused on coflowing jet diffusion flames which has a fundamental structure of many practical combustion systems. The effect of turbulence has also been evaluated by installing perforated plate in the oxidizer inlet nozzle. LPG was used as a fuel. Results showed that even though $NO_X$ emission is sensitive to the combustion air temperature, the present high temperature air combustion system produce low $NO_X$ emission because it is operated in low oxygen concentration condition in excess of dilution.

• 한국화재소방학회논문지
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• 제18권2호
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• pp.34-40
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• 2004

층류 비예혼합 분류 화염에서 다양한 주파수와 강도로 외부에서 유동장에 자극을 주었을 때 화염의 배출특성과 거동에 대해서 실험적으로 조사하였다. 먼저 일정한 관 공명 주파수에서 가진 강도를 가변시켜 난류화염 된 부상화염에서 질소산화물 배출 지수($EINO_x$)를 측정하였다. 또한, 가진 강도가 일정한 상태에서 주파수를 0 Hz에서 높은 주파수인 2 KHz까지 다양한 주파수 조건으로 가진된 한 경우에도 질소산화물의 배출지수를 측정하였다. 큰 가진 강도의 관공명 주파수로 가진된 경우 부상된 난류화염에서 $NO_x$ 배출 특성은 다음과 같이 크게 세 가지 형태의 특성을 보였다. Group I의 화염에서는 공간적인 섭동이 크며 비교적 화염길이가 길고 높은 $NO_x$ 배출 특성을 보였으며 Group II에서는 상대적으로 짧은 길이와 좁은 폭의 화염거동에 낮은 $NO_x$배출 특성을 보였다. Group III에서는 약간 긴 화염길이에 매우 큰 화염체적으로 상당한 높이까지 시ㆍ공간적으로 섭동이 큰 운동양태로 부상되는 거동과 가장 높은 $NO_x$ 배출 특성을 보였다.