• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.8
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• pp.639-648
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• 2013

This paper describes on the NOx/CO emission characteristics, temperature characteristics and flame structures when firing coal derived synthetic gas especially for gases of Buggenum and Taean IGCC. These combustion characteristics were observed by conducting ambient-pressure elevated-temperature combustion tests in GE7EA model combustor when varying heat input and nitrogen dilution ratio. Nitrogen addition caused decrement in adiabatic flame temperature, thus resulting in the NOx reduction. At low heat input condition, nitrogen dilution raised the CO emission dramatically due to incomplete combustion. These NOx reduction and CO arising phenomena were observed at certain flame temperature of $1500^{\circ}C$ and $1250^{\circ}C$, respectively. As increasing nitrogen dilution, adiabatic flame temperature and combustor liner temperature were decreased and singular points were detected due to change in flame structure such as flame lifting. From the results, the effect of nitrogen dilution on the NOx/CO and flame structure was examined, and the test data will be utilized as a reference to achieve optimal operating condition of the Taean IGCC demonstration plant.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.685-693
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• 2011

In the era of energy climate, IGCC technology is one of the powerful solutions for the demands of new energy with low carbon green growth. The present study is conducted to investigate the combustion characteristics of syngas from the coal gasifier to predict problems when it is fed to the gas turbine. Through high and low combustion tests, we understood that hydrogen is the main reason of NOx emission but easily controled by injecting the dilution of nitrogen. CO emission of syngas was comparable with that of methane and pressure fluctuation of syngas was not significant. The data from this study will be used for the optimization of combustion in the Korea first IGCC plant in 2015.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2003.05a
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• pp.513-516
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• 2003

가스터빈 복합발전은 우리나라 총 발전설비 용량의 약 25%를 차지하고 있다. 따라서 이들 가스터빈의 안정적인 운전을 위한 연소관리기술의 개발이 필요하며, 특히 발전설비의 대기오염물 배출기준이 점차 강화됨에 따라 가스터빈의 저NOx 연소 운영기술의 확보가 필수적이다. 국내에는 서인천복합, 신인천복합, 울산복합 및 보령복합 발전소 등에 건식 저 NOx 연소기가 설치되어 운영 중에 있으며 신규 건설중인 복합발전소에는 모두 이들이 설치될 예정이다.(중략)

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.3
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• pp.251-257
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• 2012

This work presents an experimental investigation of NOx emissions according to inlet air temperature (550-660 K), stoichiometric air ratio (${\lambda}$, 1.4-2.1), and elevated pressure (2-5 bar) in a High Press Combustor (HPC) equipped with a double cone burner, which was designed by Pusan Clean Coal Center (PC3). The exhaust-gas temperature and NOx emissions were measured at the end of the combustion chamber. The NOx emissions generally decreased as a function of increasing ${\lambda}$. On the other hand, NOx emissions were influenced by ${\lambda}$, inlet air temperature and pressure of the combustion chamber. In particular, when the inlet air temperature increased, the flammability limit was extended to leaner conditions. As a result, a higher adiabatic temperature and lower NOx emissions could be achieved under these operation conditions. The NOx emissions that were governed by thermal NOx were greatly increased under elevated pressures, and slightly increased at sufficiently low fuel concentrations (${\lambda}$ >1.8).

• 한국연소학회:학술대회논문집
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• 2012.04a
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• pp.7-8
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• 2012

The effects of interaction between partially premixed and premixed swirl flames on CO and NOx emissions were experimentally investigated using a hybrid/dual swirl jet combustor for a micro-gas turbine. Under the condition of constant angle ($45^{\circ}$) for outer swirl vane, the angle and direction of inner swirl vane installed for a partially premixed flame were varied as main parameters with a constant fuel flow rate for each nozzle. It was found that for all conditions, CO and NOx emissions were measured below 4 ppm and 15 ppm at 15% $O_2$, respectively, in a wide range of equivalence ratio (0.6~0.9). For co-swirl flows, CO emission increased dramatically as the angle of inner swirl vane increased from $15^{\circ}$ to $45^{\circ}$ near lean-flammability limit (i.e. equivalence ratio of 0.5). On the other hand, the case of swirl $angle=45^{\circ}$ provided the lowest NOx emission at higher equivalence ratios than 0.6. For counter-swirl flows, the case of swirl $angle=45^{\circ}$ extended the lean-flammability limit but higher NOx emissions were found compared to those of co-swirl flows. These results could be inferred by interaction between (inner) partially premixed and (outer) premixed swirl flames. However, these estimations were not clear yet because there was insufficient data on turbulent flow structure and fuel-air mixing in the present experimental approach.

• New & Renewable Energy
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• v.7 no.3
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• pp.67-73
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• 2011

MGT fuelled by landfill gas was tested to asses feasibility of its exhaust gas application for $CO_2$ enrichment. The exhaust gas was analyzed during start-up and normal operation with different MGT load conditions. Due to the changes of air/fuel ratio and combustion mode, $O_2$, $CO_2$, CO and NOx concentration were varied within wide ranges during the MGT start-up. Especially, NOx emissioin level was increased up to 20.01 ppmv. Different tendencies of $O_2$, $CO_2$, CO and NOx concentrations were observed with MGT output changes. $O_2$ and CO concentrations were shown to be decreased and NOx and $CO_2$ concentrations were shown to have opposite trends. NOx emission level (0.8~1.88 ppmv) was very low compared to other types of combustion based power generation equipment. Unburned hydrocarbon emission level was substantially decreased with MGT load increase. Especially, $C_2H_4$ concentration was below the detection limit(0.2 ppmv) around the nominal load condition. The exhaust gas from landfill gas fuelled MGT system was shown to be feasible for $CO_2$ fertilization. Concentrations of major components were within or below the maximum allowable ranges.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.5
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• pp.570-576
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• 2017

Gas turbine system with steam injection has shown outstanding advantages such as high specific power and NOx reduction. In the present work, a comparative exergetic analysis was carried out for Steam Injected Gas Turbine (STIG), Regenerative Steam Injected Gas Turbine (RSTIG), and Regenerative After Fogging Gas Turbine (RAF). Effects of pressure ratio, steam injection ratio and steam injection method on the system performance was theoretically investigated. The results showed that the order of the highest exergy efficiency is RSTIG, RAF, and STIG for low pressure ratios but STIG, RSTIG, and RAF for high pressure ratios. In each arrangement, the combustion chamber has the highest exergy destruction and the compressor has the second one.

• Aerospace Engineering and Technology
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• v.6 no.1
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• pp.29-34
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• 2007

On the stage of combustor development process, many aerodynamic and combustion characteristics are found out not by only ideal design concept but by only useful tests which are top confidentiality of technically advanced engine development companies, RR and GE, etc. In this study, test techniques of one of that company are analysed and described about some unique tests for test low emission combustors.

• Proceedings of the KSME Conference
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• 2001.06d
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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.

• 한국연소학회:학술대회논문집
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• 2012.04a
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• pp.201-202
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• 2012

The isothermal flow structure and mixing characteristics of a hybrid/dual swirl jet combustor for micro-gas turbine were numerically investigated. Location of pilot nozzle, angle and direction of swirl vane were varied as main parameters with constant fuel flow rates for each nozzle. As a result, the variation in location of pilot nozzle resulted in significant change in turbulent flow field near burner exit, in particular, center toroidal recirculation zone (CTRZ) as well as turbulent intensity, and thus flame stability and emission characteristics might be significantly changed. The swirl angle of $45^{\circ}$ provided similar recirculating flow patterns in a wide range of equivalence ratio (0.5~1.0). Compared to the co-swirl flow, the counter-swirl flow leaded to the reduction in CTRZ and fuel-air mixing near the burner exit and a weak interaction between the pilot partially premixed flame and the lean premixed flame. With the comparison of experimental results, it was confirmed that the case of co-swirl flow and swirl $angle=45^{\circ}$ would provided an optimized combustor performance in terms of flame stability and pollutant emissions.