• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.15-16
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• 2012

The present study aims to investigate quantitatively the hydrodynamic effect on combustion process of pulverized coal particles in large scale combustion chamber using computational analysis, with a general purpose computational fluid dynamics code. Burner hydrodynamics include swirl and turbulence intensity from the burner. To understand the phenomena which are difficult to observe how flow has influence on the combustion process, comparative effect of combustion related coal properties and hydrodynamics is evaluated on flame formation and development in burner flames.

• Journal of the Korean Society of Combustion
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• v.11 no.4
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• pp.22-26
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• 2006

To meet the environmental requirements, Doosan Heavy Industries & Construction Co., Ltd. (Doosan) had developed low NOx pulverized coal burner and it was applied to boiler retrofit project, 130 ton/hr coal fired cogeneration boiler, in 2003. NOx emissionand unburned carbon (UBC) in fly ash were measured during the commissioning tests. In this paper, the operation results of low NOx pulverized coal burner installed in 130 ton/hr coal fired boiler are presented. Burners emitted 160 ppm (@6 % $O_2$ basis) NOx and 3 % UBC with Chinacoal containing 0.86 % fuel nitrogen. And also it was shown that NOx emission rate of low NOx pulverized coal burner is linearly increased with fuel-nitrogen fraction of coal.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1751-1755
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• 2004

Increasing environmental pressures to reduce NOx emission are being placed on coal-fired boilers. To meet the environmental requirements, Doosan Heavy Industries & Construction Co., Ltd.(Doosan) has developed low NOx pulverized coal burner. Low NOx pulverized coal burner has already delivered, and it's combustion performance was evaluated to the NOx and Unburned Carbon(UBC) during the commissioning tests. The test results are shown that the strong relationship is existed between NOx and OFA flow rate, and also fuel-N fraction of coal has effected on NOx emission.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.379-384
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• 2003

Coal-burning utilities are facing a major NOx control compliance challenge due to the heavy emission regulation. In response to this challenge, some applicative technologies to effectively reduce NOx are developed and applied in the pulverized coal power plants. One of these is low NOx burner(LNB) equipped with multi-staged air register. In this study, NOx emission rate and flame shapes are investigated with secondary and tertiary air flow conditions in air staged coal burner, and the optimal windows of flow conditions to minimize NOx emission rate are found out. The test conditions treated in this study are the flow rate, swirl direction and intensity and throat injection velocity of secondary and tertiary air.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.95-95
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• 2010

An apparatus for generating flames and more particularly the microwave plasma burner for generating high-temperature large-volume plasma flame was presented. The plasma burner was composed of micvrowave transmission lines, a field applicator, discharge tube, coal and gas supply systems, and a reactor. The plasma burner is operated by injecting coal powders into a 2.45 GHz microwave plasma torch and by mixing the resultant gaseous hydrogen and carbon compounds with plasma-forming gas. We in this work used air, oxygen, steam, and their mixtures as a discharge gas or oxidant gas. The microwave plasma torch can instantaneously vaporize and decompose the hydrogen and carbon containing fuels. It was observed that the flame volume of the burner was more than 50 times that of the torch plasma. The preliminary experiments were carried out by measuring the temperature profiles of flames along the radial and axial directions. We also investigated the characteristics for coal combustion and gasification by analyzing the byproducts from the exit of reactor. As expected, various byproducts such as hydrogen, carbon monoxide, carbon dioxide, hydrogen sulfide, etc. were detected. It is expected that such burner cab be applied to coal gasification, hydrocarbon reforming, industrial boiler of power plants, etc.

• Clean Technology
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• v.28 no.2
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• pp.117-122
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• 2022

This study developed and tested an ultra-low NO_x burner in an 80 kW combustion furnace. The experiment was conducted in an 80 kW single burner combustion furnace with changing the swirl numbers, total equivalence ratios, and primary/secondary oxidizer ratios. In this study, liquefied natural gas (LNG) was used as an auxiliary fuel to significantly reduce NO_x production. In a thermal power plant, the amount of NO_x generated during coal combustion is about 300 ppm. However, using the burner tested in this study, it was possible to reduce the amount of NO_x generated via LNG co-firing to 40 ppm. If the input amount of the primary oxidizer is enough for the gas to be completely combusted and the gas and coal are added simultaneously, the combusted gas forms a high-temperature region at the burner outlet and volatilizes the coal. As a result, the N contained in the devolatilized coal is discharged. Therefore, when the coal is subsequently burned, the amount of NO_x produced decreases because there is almost no N remaining in the coal. If a thermal power plant burner is developed based on the results of this study, it is expected that the NO_x generation will be significantly lower in the early stage of combustion.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.102-105
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• 2001

Numerical simulations of coal combustion were carried out to identify what kind of burner design parameters are affecting the NOx emission. Where used burner design parameters are primary air velocity, secondary air velocity, $2^{nd}/3^{rd}$ air ratio, tertiary air velocity, and tertiary air injection location. Taguchi method was used to find the effective burner design parameters related to NOx formation. The results of numerical simulations showed that secondary air velocity and $2^{nd}/3^{rd}$ air ratio was the key parameters reducing the NOx emission. The total number of simulation cases was reduced by Taguchi method.

• Journal of the Korean Society of Combustion
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• v.11 no.2
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• pp.1-6
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• 2006

This report presents a study of the development of an advanced coal nozzle used in burners to reduce unburned carbon (UBC) in a tangential coal-fired boiler. To understand the mechanism of UBC reduction, experiments using conventional burners were carried out to evaluate the effects of air injection velocity, coal fineness and over fired air (OFA) on combustion efficiency. It was confirmed that ignition of pulverized coal particles close to the burner is helpful toward the complete burn of residual carbon in fly ash. These efforts indicated the additional results that UBC was strongly dependent on the primary air velocity and coal fineness; especially that UBC dramatically decreased when the weight fraction of pulverized coal under $75{\mu}m$ was over 85 %. New coal nozzles, modified from conventional nozzles, were prepared and tested to improve the combustion efficiency. Some of these nozzles offered relatively lower unburned carbon than those of conventional burners and are referred to as HPFS (High Performance Flame Stability) coal nozzles.

• 한국연소학회:학술대회논문집
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• 1998.10a
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• pp.79-84
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• 1998

In this paper we show design and operation of 1MWth pulverized coal combustion test facility. The test facility is consists of coal feeding system, furnace and flue gas treatment system. The furnace is equipped with a top-fired burner in order to avoid influence of gravity on the coal particles. There are two part of vertical(VP) and horizontal pass(HP) at furnace. We can measure temperature and species of coal flames in vertical pass. Also, there is horizontally arranged section where investigation regarding corrosion and deposit formation will be carried out. The burner of combustor was externally air staging burner(EASB) type made by IFRF. The pulverized high bituminous(Blair athol) coal from Australia was used as fuel, and the particle size less than 80 ${\mu}m$ was 83.4%. Overall excess air ratio was 1.2.

• 한국연소학회:학술대회논문집
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• 2001.11a
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• pp.153-160
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• 2001

The combustion test used DTF was performed to obtain the characteristics of NOx emission and reduction. In this test, major factor of NOx emission was a stoichiometric air ratio. At the onset of combustion to be rich oxygen, NOx was produced rapidly. Optimum condition for NOx reduction was formed under about AR:0.7 in the combustion test of Alaska coal. Investigations were undertaken with 200KW(th) test combustor. In combustion test, the major variables were coal feed ratio of center/outer, stoichiometric air ratio at the onset of combustion. The lowest NOx emission, 182ppm(6% O2 base), was achieved at about AR:0.6 of the first combustion stage with low NOx burner. Also, unburned carbon content of char collected in this combustion condition was about 1wt%.