• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.8 s.251
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• pp.788-795
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• 2006

From the view of the environmental protection against the use of fossil fuels, the great of efforts have been exerted to find an effective method which is not only pollutant reduction but also high thermal efficiency. Reburning is a useful technology in reducing nitric oxide through injection of a secondary hydrocarbon fuel. In this paper, an experimental study has been conducted to evaluate the hybrid effects of reburning and selective non-catalytic reaction (SNCR) on $NO_x/CO$ reduction from oxygen-enriched LPG flame. Experiments were performed in flames stabilized by a co-flow swirl burner, which was 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 $NO_x$ generation were observed to increase by oxygen-enriched combustion, but due to its hybrid effects of reburning and SNCR, $NOx/CO$ concentration in the downstream has considerably decreased.

• Journal of the Korean Society of Combustion
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• v.14 no.4
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• pp.17-24
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• 2009

Reburning is one of the most useful technologies for reducing nitric oxide in economically and technically. The reburning process was demonstrated as an effective NOx reduction method through injection of a secondary hydrocarbon fuel. An experimental study has been conducted to evaluate the effect of biomass reburning on NOx and CO formation in a light oil flamed combustion furnace. Reburning tests on NOx reduction of air-carried rice husk powder as the reburn fuel and light oil as the main fuel were performed in flames stabilized by a co-flow swirl and fuel staged burner, which was mounted at the front of the furnace. The results included flue gas emissions and temperature distribution in the furnace for several kinds of experimental conditions. It was observed clearly that NOx concentrations in the exhaust have considerably decreased due to effect of biomass reburning. The maximum NOx reduction rate was 42% when the reburn fuel fraction was 0.18. The CO emissions were kept under 42 ppmv in all experimental tests. And this paper makes clear that in order to decrease NOx concentration in the exhaust when the biomass reburning system is adapted, the control of some factors such as reburn fuel fraction and reburn zone fraction is very important.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.3
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• pp.216-223
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• 2008

Reburning is a useful technology in reducing nitric oxide through injection of a secondary hydrocarbon fuel. In this paper, an experimental study has been conducted to evaluate the effect of fuel lean reburning on $NO_X/CO$ reduction in LPG flame. Experiments were performed in flames stabilized by a co-flow swirl burner, which was mounted at the bottom of the furnace. Tests were conducted using LPG gas as the reburn fuel as well as the main fuel. The effects of reburn fuel fraction and injection location of the reburn fuel were studied when the fuel lean reburning system was applied. The paper reports data on flue gas emissions and temperature distribution in the furnace for a wide range of experimental conditions. At steady state, temperature distribution and emission formation in the furnace have been measured and compared. This paper makes clear that in order to decrease both NOx and CO concentrations in the exhaust when the fuel lean reburning system was adapted, it is important that the control of some factors such as initial equivalence ratio, reburn fuel fraction and temperature of reburn fuel injection region. Also it shows the fuel lean reburning is also effective method to reduce NOx as much as reburning.

• Journal of the Korean Society of Combustion
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• v.14 no.4
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• pp.41-47
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• 2009

An experimental study was performed to confirm the effect of the changing combustor pressure(-30~30 kpa), combustion characteristics were investigated by measuring the local chemiluminescence intensity, the local temperature distribution and emission. In order to investigate combustion ones, the combustor pressure index($P^*$) was controlled in the range of 0.7~1.3 for each equivalence ratio in the present combustion system, where $P^*$ is defined as the ratio of absolute pressure to atmospheric one. The local mean temperature showed the uniform distributions for lower pressure index, which increased with increasing equivalence ratio. The mean $OH^*$ chemiluminescence intensity, showed high level for lower pressure index for ${\Phi}{\get}1.0$ conditions. EINOx decreased with decreasing pressure index for overall equivalence ratio conditions.

• Journal of the Korean Institute of Gas
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• v.25 no.6
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• pp.22-28
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• 2021

Combustion characteristics were examined experimentally for a swirl-stabilized double cone premixed burner nozzle used for industrial gas turbines for power generation. An original model and a variant with a different fuel injection pattern are tested to compare their combustion characteristics such as NOx, CO and stability in pressurized conditions with single burner-flame and in an ambient multi-flame conditions with multi-burners. Test results show that NOx emissions are smaller for the variant, whose number of fuel holes is reduced with the same total area of fuel holes, in ambient and pressurized single-flame conditions with single burner, which results from enhanced fuel/air mixing due to a higher penetration of fuel into the air stream. The multi-burnerflame test results show that NOx emissions are smaller for the variant due to reduced flame interactions, which, on the contrary, slightly reduces the stability margin. On-site test results fromin an actual power plants also show that NOx emissions are reduced for the variant, compared with the original one, which is in agreement with the lab test results stated above.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.1
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• pp.51-57
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• 2013

This study aims to experimentally investigate the combustion characteristics of a lean premixed swirl-stabilized burner with dual-stage fuel injection arrays. The results show that a variation in the fuel distribution to fuel stages 1 (upstream) and 2 (downstream) produces a noticeable change in the NOx and CO emissions. Reducing the confined ratio, defined as the ratio of the nozzle exit diameter to the liner diameter, may reduce NOx and CO emissions owing to reduced combustion loading and longer residence time, respectively. A nozzle exit velocity of 30 m/s shows the optimum characteristics in terms of NOx and CO emissions and flame stability: increasing or decreasing the nozzle exit velocity leads to a degradation in emissions or flame stability, respectively.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.187-199
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• 2011

The main objective of this study was investigation of natural gas flames in a lean premixed swirl-stabilized dump combustor with an attention focused on the effect of the various fuel-air mixing section geometry on the combustion instability characteristics. The multi-channel dynamic pressure transducers were located on the combustor and inlet mixing section region to observe combustion pressure oscillation and difference phase at each dynamic pressure measurement results. Dynamic pressures were also measured to investigate characteristics of combustion at the same time. The combustor and mixing section length was varied in order to have different acoustic resonance characteristics from 800 to 1800 mm in combustor and 470, 550, 870 mm in mixing section. We observed two dominant instability frequencies in this study. Lower frequencies were obtained at lower equivalence ratio region and it was associated with a fundamental longitudinal mode of combustor length. Higher frequencies were observed in higher equivalence ratio conditions. It was related to secondary longitudinal mode of coupled with the combustor and mixing section. In this instability characteristics, pressure oscillation of mixing section part was larger than pressure oscillation of combustor. As a result, combustion instability was strongly affected by acoustic characteristics of combustor and mixing section geometry.

• Journal of the Korean Institute of Gas
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• v.24 no.1
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• pp.49-55
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• 2020

Experimental investigations were conducted to understand the multi-staged combustion characteristics of a swirl-stabilized double cone premixed burner nozzle used for industrial gas turbines for power generation. Multi-staged combustion is implemented by injecting the fuel through the existing manifold of the side slots as well as through the apex of the cone with two fuel injection angles which are slanted or axial. NOx and CO emissions, and wall temperature distributions were measured for various fuel distributions and operating conditions. Results show that NOx emissions are decreased when the fuel distribution to the apex is 3% of the total amount of fuel, which is due to more uniform fuel distribution inside the nozzle, hence less hot spots at the flame. NOx emissions are rather increased when the fuel distribution to the apex is 8% of the total amount of fuel for axial fuel injection by occurrence of flash back in premixing zone of burner.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.4
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• pp.57-69
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• 2012

The main objective of this study was investigation of natural gas flames in a lean premixed swirl-stabilized dump combustor with an attention focused on the effect of the various fuel-air mixing section geometry on the combustion instability characteristics. The combustor and mixing section length was varied in order to have different acoustic resonance characteristics from 800 to 1800 mm in combustor and 470, 550, 870 mm in mixing section. We observed two dominant instability frequencies in this study. Lower frequencies were associated with a fundamental longitudinal mode of combustor length. Higher frequencies were related to secondary longitudinal mode of coupled with the combustor and mixing section. As a result, combustion instability was strongly affected by acoustic characteristics of combustor and mixing section geometry.