• 한국연소학회:학술대회논문집
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• 한국연소학회 2002년도 제25회 KOSCI SYMPOSIUM 논문집
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• pp.105-112
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• 2002

The objective of this research is to determine generally applicable design principles for the development of internally staged combustion devices. Utilizing a triple annulus combustor, air staged commercial propane flame configuration are studied. For this triple air staged combustor, the angular momentum weighted by it's swirl number and air distribution ratio was observed to be the critical criteria. An internal recirculation zone which develops on the centerline of the flame immediately downstream of the burner entraps the fuel into a fuel rich eddy. Then sufficient heat must he transferred from the flame via radiation to the chamber heat transfer surfaces, such that when the second air is introduced, peak flame temperatures are suppressed. It is experimentally found out that the total NOx emission level in this type of burner is lower than 0.75g/kg.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.169-172
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• 1999

In this experimental study we Proposed the double dielectric barrier discharge (DDBD) reactor to produce as high an electric field as possible. The experiment are conducted for applied voltage from 15 to 20[tV], flow gas rage at 2[1/min] and pulse rate at 120[pulses/s] and 240[pulses/s]. SPD connection of DDBD which combine the surface discharge with the silence discharge was most effective to reduce the NOx. In the decomposition efficiency per watt, the low pulse rate gave hotter efficiency than that of the high pulse rate. However in DeNOx rate, the high pulse rate gave better performance than that of the low pulse rate. NOx removal rate increased with increasing the applied voltage in all reactors.

• 한국연소학회지
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• 제14권1호
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• pp.9-18
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• 2009

The NOx emission characteristics of DME in counterflow nonpremixed flames were investigated numerically, and brief experiments were carried out to compare the flame shapes and NOx emissions with those of $C_{3}H_{8}$ and $C_{2}H_{6}$. The DME flames were calculated using Kaiser's mechanism, while the $C_{2}H_{6}$ flames were calculated using the $C_3$ mechanism. These mechanisms were combined with the modified Miller-Bowman mechanism for the analysis of NOx. Experimental results show that DME flame has the characteristics of partial premixed flame and the flame length becomes very shorter compared with general hydrocarbon fuels and then, the NOx emission of DME is low as much as 60 % of $C_{3}H_{8}$. In the calculated results of counterflow nonpremixed flames, the $EI_{NO}$ of DME nonpremixed flame is low as much as 50 % of the $C_{2}H_{6}$ nonpremixed flame. The cause of $EI_{NO}$ reduction is attributed mainly to the characteristics of partial premixed flame due to the existence of O atom in DME and partly to the O-C bond in DME, instead of C-C bond in hydrocarbon fuels.

• 한국연소학회지
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• 제12권4호
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• pp.14-21
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• 2007

In order to enhance combustion efficiency, oxygen-enriched combustion is used by increasing the oxygen ratio in the oxidizer. However, since the flame temperature increases, NOx formation in the furnace seriously increases for low oxygen enrichment ratio. In this case, reburning is a useful technology for reducing nitric oxide. In this research, experimental studies have been conducted to evaluate the hybrid effects of reburning/selective non-catalytic reaction (SNCR) and reburning/air staging on NOx formation and also to examine heat transfer characteristics in various oxygen-enriched LPG flames. Experiments were performed in flames stabilized by a co-flow swirl burner, which were mounted at the bottom of the furnace. Tests were conducted using LPG gas as main fuel and also as reburn fuel. The paper reported data on flue gas emissions, temperature distribution in furnace and various heat fluxes at the wall for a wide range of experimental conditions. Overall temperature in the furnace, heat fluxes to the wall and NOx generation were observed to increase by low level oxygen-enriched combustion, but due to its hybrid effects of reburning, SNCR and Air staging, NOx concentration in the exhaust have decreased considerably.

• 대한기계학회논문집B
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• 제25권11호
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• pp.1616-1623
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• 2001

A basic experimental study has been carried out to find out the design parameters of fuel 2-staging atomizers in order to reduce nitrogen oxides(NOx) rate emitted from the steam boilers used the liquid fuel. The heavy fuel oil(B-Coil) and fuel 2-staging Y-jet twin-fluid atomizers were adopted in this study. The results of this paper were obtained from the real as well as the model scale atomizers. In the case of model atomizers test, NOx reduction rate was strongly dependent on the staged fuel rate, but it was weakly dependent on the injection hole arrangement and air swirl conditions. The real scale atomizers was designed and manufactured on the base of these test results, and those was mounted and operated in the real boiler generates 185 ton steam per an hour. The reduction rate of the model and real plant was reached 10∼30% of base NOx by atomizers. but dust was sharply increased in the low O$_2$combustion region of the real plant.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.1973-1978
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• 2008

The NOx emission characteristics of DME in counterflow nonpremixed flames were investigated numerically, and brief experiments were carried out to compare the flame shapes and NOx emissions with those of $C_3H_8$ and $C_2H_6$. The DME flames were calculated using Kaiser's mechanism, while the $C_2H_6$ flames were calculated using the $C_3$ mechanism. These mechanisms were combined with the modified Miller-Bowman mechanism for the analysis of NOx. Experimental results show that DME flame has the characteristics of partial premixed flame and the flame length becomes very shorter compared with general hydrocarbon fuels and then, the NOx emission of DME is low as much as 60% of $C_3H_8$. In the calculated results of counterflow nonpremixed flames, the EINO of DME nonpremixed flame is low as much as 50% of the $C_2H_6$ nonpremixed flame. The cause of $EI_{NO}$ reduction is attributed mainly to the characteristics of partial premixed flame due to the existence of O atom in DME and partly to the O-C bond in DME, instead of C-C bond in hydrocarbon fuels.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1999년도 추계 학술발표회 논문집
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• pp.23-29
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• 1999

Experimental studies are conducted to investigate the flame stability and the thermal/fuel NOx formation characteristics of the low calorific value (LCV) coal derived gas fuel. Synthetic LCV fuel gas is produced by mixing carbon monoxide, hydrogen, nitrogen and ammonia on the basis that the thermal input of the syngas fuel into a burner is identical to that of natural gas. The syngas mixture is fed to and burnt with air on flat flame burner. With the variation of the equivalence ratio for specific syngas fuel, flame behaviors are observed to identify the flame instability due to blow-off or flashback and to define stable combustion range. Measurements of NOx content in combustion gas are made for comparing thermal and fuel NOx from the LCV syngas combustion with those of the natural gas one. In addition, the nitrogen dilution of the LCV syngas is preliminarily attempted as a NOx reduction technique, and its effects on thermal and fuel NOx production are discussed.

• 청정기술
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• 제26권3호
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• pp.211-220
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• 2020

본 연구는 80 kW급 단일버너 연소로에서 석탄 연소시 초저 NOx 버너 설계인자를 평가하기 위한 실험적 연구이다. 버너 설계 인자인 선회강도, 총 과잉 공기비, 버너 영역 과잉공기비, 1차/2차 산화제 비율, OFA 비율을 변경하여 총 81개 조건을 대상으로 실험을 수행 하였다. 실험 결과, 선회류가 약하면 연소로 출구에서 CO가 증가하고 연소로 내부 온도가 감소하는 것으로 나타났다. 그러나, 선회류가 강하면 NOx가 증가하기 때문에 적절한 선회류 강도를 결정하는 것은 NOx를 줄이는 데 중요한 요소이다. 1차/2차 산화제의 비율 또한 중요한 요소이며, 생성 된 NOx의 양은 산화제의 비율에 따라 달라진다. 2차 산화제의 비율이 증가하면 연소 초기에 NOx 방출량이 증가하고, 측정 된 배출구 NOx가 증가하게 된다. 그러나, 2차 산화제 비율이 감소하면 화염이 길어지고 CO가 증가한다. 본 연구에 사용 된 연소 시스템은 적절한 조건이 만족 될 때 O₂ 6%를 기준으로 최소 NOx가 82 ppm 생성되는 것으로 확인 되었다. 본 실험에서 대상으로 한 버너는 연소용 공기를 석탄을 이송하는 1차공기 외에 2차공기로 하나의 산화제 유동만 사용하는 방식으로서 추후 3차 및 4차공기로 분할하여 화염형태 및 반응을 세밀하게 제어할 경우 추가적인 NOx 감소가 가능할 것으로 예상된다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.3096-3101
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• 2008

Selective Catalytic Reduction (SCR) technology is well-known to be effective for the reduction of NOx emission. So car manufacturers has adopted Ures-SCR system to be satisfied with emission regulation. This paper discusses the effective of $NH_3/NOx$ ratio and SCR catalyst temperature in the $NH_3$-SCR reactor on DeNOx performance. So it is shown the characteristic of NOx conversion and ammonia slip using the $NH_3$ instead of Urea-Solution. From the result of this study, it is found to optimize $NH_3/NOx$ ratio to have the best case of high NOx conversion and low ammonia slip at variable SCR catalyst temperatures. Lastly, it is also found the characteristics of NOx conversion and ammonia slip with compared with Urea.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2000년도 춘계 학술발표회 논문집
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• pp.293-298
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• 2000