• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2175-2180
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• 2008

Oxy-fuel combustion has been gaining its significance as a means of migrating the green house effects. Some experimental measurements were conducted to investigate the characteristics of oxy-fuel combustion and to aid a fundamental design of a lab-scale oxy-fuel combustor with a coaxial burner. CO emission was measured along the combustor centerline while combustion of methane and oxygen diluted by CO2 took place. Substitution of CO2 with N2 indicates a possibility that some CO is formed by dissociation of CO2. Some parametric tests were also performed to see the mixing effects of reactant gases on CO emission by changing the gas injection velocity at the burner nozzles with various heat loads. The overall results indicate that CO emission was reduced when the reactants are injected at higher velocities of similar magnitude.

• Journal of the Korean Society of Combustion
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• v.9 no.1
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• pp.1-10
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• 2004

The results of a series of experiments executed by using two pilot-scale oxy-fuel burners are presented. The oxy-fuel burners are designed for maximum capacity of 50,000kcal/hr, 200,000kcal/hr and installed in the test furnace. The effects of turn-down ratio, excess oxygen ratio, nozzle exit velocity, injection angle, and swirl vane angle on the combustion characteristic are investigated. Temperature distributions are measured using R-type and Molybdenum sheathed C-type thermocouple at various points of the flame. The results showed that maximum temperature and mean temperature increase with the increase of turn-down ratio and momentum. The maximum flame temperature was increased about 35% compared to the case of equivalent air operated condition. In addition, optimum burner type, excess oxygen ratio and nozzle characteristics are obtained for this oxy-fuel glass melting furnace.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3276-3281
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• 2007

A novel oxy-fuel burner for a boiler has been devised and composed into a 50 kW class boiler system. A series of test has been conducted to show the characteristics of combustion, exhaust gas and the boiler. Numerical simulations have been also performed and validated against the experimental data to discuss detailed physics. The oxy-fuel burner can effectively heat the combustion chamber with the significantly reduced combustion gas, which enables to realize the compactness of the system. The composition of exhaust gas reveals that the sealing of the system is crucial to achieve high $CO_2$ concentration and low $NO_X$ emission.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.7
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• pp.504-512
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• 2008

The characteristics of nonpremixed oxy-fuel flame in a multi-jet burner were experimentally and numerically investigated. The overall flow rate of fuel and oxygen was fixed, and the oxygen feeding ratio (OFR) was varied by 0.25, 0.5, and 0.75. The results of numerical simulation were compared with the measured results which are temperature profile and direct flame observation. The probability density function (PDF) model was applied accounting to the description between turbulence and chemistry, and standard ${\kappa}-{\varepsilon}$ model was used for turbulent flow field. Equilibrium assumption is very reasonable due to fast chemistry of the oxy-fuel combustion. Thus, the equilibrium calculation based on Gibbs free energy minimization was guaranteed to generate the solution of the oxy-fuel combustion. The result was obtained by numerical simulation. The predicted radial temperature profiles were in good agreement with the measured results. The flame length was shorten and was intensified with the decrease of OFR because the mixture of fuel and oxidizer are fast mixed and burnt. The maximum temperature became lower as the OFR increased, as a consequence of large flame surface area.

• 한국연소학회:학술대회논문집
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• 2006.10a
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• pp.229-234
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• 2006

The oxy-fuel combustion heating characteristics is investigated experimentally by measuring furnace and steel temperature variations for batch type furnace simulator with a specially designed low NOx oxy-fuel burner. Economics of using oxy-fuel combustion is confirmed and, the furnace and steel temperature variations for different heating conditions are compared to deduce optimal heating control pattern for energy savings and rapid uniform heating. High $CO_2$ concentration (> 80-90%), low NOx (< 40ppm) and CO (< 10ppm) are measured in the flue gas. Temperature differences (< $30^{circ}C$) inside the furnace and steel are reduced relatively by increasing the burner jet momentum.

• 한국연소학회:학술대회논문집
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• 2004.11a
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• pp.175-180
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• 2004

Improving furnace efficiency is a high priority need for aluminum, glass, steel and other metal casting industries. Oxy-fuel combustion is considered to be one of the most effective method to improve thermal efficiency and reduce $NO_x$, SOx and $CO_2$ emissions for high temperature furnaces. The characteristics of an oxy-fuel flame, in particular its shape, radiation profile and exhaust gas composition are considerably different to those of an air-fuel burner. For this reason, a new approach is needed regarding factors such as burner design, power input levels, number and positioning strategies of burners and also control philosophies. In this paper will discuss the latest developments of high performance oxy-fuel combustion reheating furnace system. This high performance oxy-fuel combustion system will be shown to be technologically superior to other types of combustion systems in the areas of fuel efficiency, emissions and productivity.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.10
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• pp.729-753
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• 2008

Oxy-fuel combustion is a reliable way for the reduction of pollutants, the higher combustion efficiency and the separation of carbon dioxide. The review of recent research trends and the prospects of oxy-fuel combustion were presented. The difference in characteristics among oxy-fuel combustion, conventional air combustion, oxy-fuel combustion with flue gas recirculation (FGR) technique was investigated. Recent experiments of oxy-fuel combustion with/without FGR were surveyed in various ways which are optimized burner design, flame characteristics, the soot emission, the radiation effect, the NOx reduction and the corrosion of combustor. Numerical simulation is more important in oxy-fuel combustion because flame temperature is so high that conventional measurement devices have a restricted application. Equilibrium and non-equilibrium chemical reaction mechanisms for oxy-fuel combustion were investigated. Combustion models suitable for the numerical simulation of non-premixed oxy-fuel flame were surveyed.

• Journal of the Korean Society of Combustion
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• v.13 no.1
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• pp.31-43
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• 2008

Oxy-fuel flame has a significantly different structure from that of air-fuel flame because of its high temperature. This study is aimed to find out the difference of the oxy-fuel flame structure in order to understand reaction mechanism closely, which is crucial to design real-scale oxy-fuel combustion system. By examining pictures of counterflow flame and LIF images, we found that oxy-fuel flame had two-zone structure: fuel decomposition region and distributed CO oxidation region. In the oxy-fuel flame, OH radical was distributed intensely through the whole flame due to its higher flame temperature than crossover temperature. For showing those features of the oxy-fuel flame, 1 MW scale IFRF oxy-natural gas burner was simulated by conditional moment closure(CMC) model. Calculation results were compared with experimental data, and showed agreements in trend. In the simulated distributions of fuel decomposition/CO oxidation rates, CO oxidation region was also separated from fuel decomposition zone considerably, which showed the two-zone structure in the oxy-fuel flame.

• 한국연소학회:학술대회논문집
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• 2012.04a
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• pp.43-46
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• 2012

The oxygen concentration of primary oxidizer is decided under 10% due to flammable risk. It can be a spontaneous combustion inside burner or tube if the excess oxygen is added to primary oxidizer in Oxy-PC burner. In this case, the rest oxygen which can not be injected to primary oxidizer should be injected to another port. If added it to a second oxidizer, the ignition is unstable at outlet of burner. Accordingly an extra lancing port is needed to insert into the burner unlike other common air mode. And the flame formation and combustion characteristic differ from lancing port position. Therefore we observed flame formation which has stable combustion characteristic according to the shape and position of lancing port.

• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.65-68
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• 2015

Agreeable to the latest enviromental problem, CCS(Carbon Capture&Storage) technology is more significant. As these issues, Oxy-Combustion is one of the technology that realize the CCS technology and large scale field test proceeding at other places. The aims of this research were to evaluate the combustion characteristics of pressurized oxy-combusition that is attract attention as the next generation power plant. The experiments were conducted using a laboratory-scale pressuized oxy-combustor. The fuel used was low calorific value syn-gas that is mainly composed of CO(60%), $H_2$(27%). The burner was used co-axial burner, to investigate combustion characteristics, temperature in the reactor and the flue gas compositions were measured.