• Proceedings of the KSME Conference
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• 2003.11a
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• pp.314-319
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• 2003

The concept of lean-premixed combustion in gas turbine combustor operation has become a standard in recent years as an effective means to meet stringent enviromental standards on NOx emissions. The combustion characteristics of 75 kW class lean premixed combustor were investigated at the conditions of high temperature and ambient pressure. The exit temperature and emissions of CO and NOx were measured at the center of exit plane. The high temperature air of $550K{\sim}650K$ was supplied through air preheater. As expected, experimental results indicate that NOx emission was increased and CO emission was decreased by increasing inlet air temperature. But CO emission measured at the center of exit plane was increased because of the non-uniform radial direction profiles. The Semi-Empirical Correlation method was applied to obtain the design point emissions of NOx and CO. Also the flame temperature, CO and NOx emissions were measured along the centerline of liner at 650K inlet air temperature to determine the position of dilution holes.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.11
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• pp.1339-1347
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• 2004

Development of the low NOx heating boiler was strongly asked due to severe air pollution and the large number of boilers in korea. Compactness of the commercial boiler was also important because of low manufacturing cost and easy installation. In this study. newly developed compact low NOx burner, using turbulent gas diffusion combustion with multi-staged air supplies and multiple fuel nozzles, was investigated. Comparison study of the new burner was performed between experimental results and computational analysis. Commercial computational fluid dynamic(CFD) program named CFX-5.6 was used for numerical analysis of the low NOx burner inside the test combustor. Comparisons of experiment data and numerical result were performed under various equivalence ratio and fuel flow rate.

• 한국연소학회:학술대회논문집
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• 1999.10a
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• pp.201-207
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• 1999

The combustion characteristics for the low NOx 50 kW-class gas turbine combustor have been experimentally investigated. In order to achieve the premixing and the lean burn combustion, the geometries of the primary zone including premixed chamber were modified from conventional combustor. The centerline profiles of CO and NO concentration, and temperature were measured for the premixed combustors with or without dilution holes in the liner. The effects of the pilot fuel injection rate and air dilution on flame stabilization and pollutant (CO, NO) emission are discussed in detail.

• Journal of the Korean Society of Combustion
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• v.13 no.4
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• pp.37-46
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• 2008

Performance test of 5MW class gasturbine combustor was carried out at combustor test facility of KARI(Korea Aerospace Research Institute). The combustor is dry low NOx type premixed combustor and fuel is natural gas. The characteristics of combustor were measured including emission, pressure pulsation and exit temperature distribution. Optimum operation point of combustor was found by changing parameters like fuel ratio between pilot and main burner. The test result showed that the combustor performance is sufficient to satisfy the gasturbine system requirement.

• 한국연소학회:학술대회논문집
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• 2003.05a
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• pp.215-222
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• 2003

Mild combustion or Flameless oxidation(FLOX) have been considered as one of the most prospective clean-combustion technologies to meet both the targets of high process efficiency and low pollutant emissions. A mild combustor with high air preheating and strong internal exhaust gas recirculation is characterized by relatively low flame temperature, low NOx emissions, no visible flame and no sound. In this study, the Steady Flamelet Approach has been applied to numerically analyze the combustion processes and NOx formation in the mild combustor. The detailed discussion has been made for the basic characteristics of mild combustor, numerical results and limitation of the present combustion modeling.

• 한국연소학회:학술대회논문집
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• 2003.12a
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• pp.265-272
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• 2003

Some catalytic reactors for industrial/generation gas turbines were reviewed and investigated to understand the current status and future prospect for ultra low NOx catalytic gas turbine combustor. Catalytic reactor which was applied to 1${\sim}$10MW class gas turbine has achieved the ultra low emission corresponding to less than 3ppm NOx and 10ppm CO. But the durability and sizing flexibility of catalyst is needed to improve the catalyst performance for commercial gas turbine operation.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1134-1139
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• 2004

Recently, development of flame control scheme has been hot issues in the combustion engineering. It has been held that flame shape can be controllable by pressure inside combustor. The influence of combustor atmospheric pressure on flame shape was investigated in the present study. The flame shape, flammable limit, flame temperature and nitric oxide emission were measured as functions of combustor atmospheric pressure and equivalence ratio. The reaction region became longer and wider with decreasing combustor atmospheric pressure by direct photography, hence reduction of blow off limit. This tendency was also observed in the mean flame temperature distribution. Nitric oxide emission decreased with decreasing combustor atmospheric pressure. Low NOx combustion is ascribed to wide-spread reaction region in the low atmospheric pressure condition. These results demonstrate that flame shape and nitric oxide emission can be controllable with combustor atmospheric pressure.

• 한국연소학회:학술대회논문집
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• 2002.11a
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• pp.149-155
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• 2002

A promising new approach to achieve low pollutants emission and improvement of flame stabilities is tested experimentally using a hybrid cyclone jet combustor employing both premixed and diffusion combustion mode, Three kind of nozzles are used for LNG(Liquified Natural Gas) as a fuel. The combustor is operated by two method, One is ATI(Air Tangential Injection) mode, generated swirl flow by air as general swirl combustor, and the other is PTI(Premixed gas Tangential Injection) mode, The PTI mode consists of diffusion flame of axial direction and premixed cyclone flame of tangential direction in order to stabilized the diffusion flame. The results showed that the stable region of the PTI mode is more larger than the ATI mode. In addition, the reduction of NOx emission in PTI mode, as compared with that for the ATI mode is at least 50% in stable region. Also, even using the low calorific fuel as $CO_2$-blended gas, the cyclone jet combustor has high performance of flame stability.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.6
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• pp.127-134
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• 2004

Three-dimensional numerical investigations are carried out to understand the combustion characteristics inside a DLN(dry low NOx) utility gas turbine combustor during the combustion mode change period by applying transient fuel flow rates in fuel supply system as numerical boundary conditions. The numerical solution domain comprises the complex combustor liner including cooling air holes, three types of fuel nozzles, a swirl vane, and a venturi. Detailed three-dimensional flow and temperature fields before and after combustion mode changeover have been analyzed. The results may be useful for further studies on the unfavorable phenomena, such as flashback or thermal damage of combustor parts when the combustion mode changes.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.453-459
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• 2004

An axially staged combustor equipped with an LPP combustion system and CMC liner walls has been investigated for stable combustion and low NOx emissions for the ESPR project. Several fuel injectors were designed and manufactured for the LPP burner, and single sector combustor tests were conducted to evaluate fundamental combustion characteristics such as emissions, instabilities, auto-ignition, and flash back at typical operating conditions from idle to Mn 2.2 cruise. The latest test results showed that the LPP burner had a good potential for the low NOx target. It was also found that the NOx emission level was greatly affected by a distortion in the air flow velocity field upstream of the LPP burner due to the diffuser and fuel feed arm. The CMC material was investigated to apply for the high temperature and low NOx combustor. Annular combustor liner walls were manufactured with the CMC material, and they have been tested at low pressure conditions to evaluate the soundness of the material and the mounting and seal system. This paper reports the latest research activities on the LPP combustion system and CMC liner walls for the ESPR project.