• 한국연소학회:학술대회논문집
• /
• 2006.04a
• /
• pp.69-74
• /
• 2006

An Experimental study was conducted on $CO_2$ recycle combustion heating system using pure oxygen instead of conventional air as an oxidant, which is thereby producing a flue gas of mostly $CO_2$ and water vapor($H_2O$) and resulting in higher $CO_2$ concentration. The advantages of the system are not only the ability to control high temperatures characteristic of oxygen combustion with recycling $CO_2$. but also the possibility to reduce NOx emission in the flue gas. A small scale industrial reheating furnace simulator and specially designed variable flame burner were used to characterize the $CO_2$ recycle oxy-fuel combustion, such as the variations of furnace pressure, temperature and composition in the flue gas during recycle. It was found that $CO_2$ concentration in the flue gas was about 80% without $CO_2$ recycle, but increased to $90{\sim}95%$ with $CO_2$ recycle. The furnace temperature and pressure was decreased due to recycle and the NOx emission was also reduced to maintain under 100ppm.

• 한국연소학회:학술대회논문집
• /
• 2015.12a
• /
• pp.121-121
• /
• 2015

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.34 no.4
• /
• pp.409-416
• /
• 2010

The use of oxy-fuel combustion and flue gas recirculation (FGR) for $CO_2$ reduction has been studied by many researchers. This study focused on the characteristics of oxy-fuel combustion and the effects of $CO_2$ addition from the point of view of oxygen feeding ratio (OFR) and the position of $CO_2$ addition in order to reproduce an FGR system with a triple concentric multi-jet burner. Oxy-fuel combustion was stable at all OFRs at a fuel flow-rate of 15 lpm, which corresponds to an equivalence ratio of 0.93; however, the structure and length of the flame varied at different OFRs. When $CO_2$ was added in oxy-fuel combustion, various stability modes such as stable, transient, quasistable, unstable, and blow-out were observed. The temperature in the combustion chamber decreased upon $CO_2$ addition in all conditions, and the maximum reduction in temperature was below 1800 K. $CO_2$ concentration with respect to height varied with the volume percent of $CO_2$ at the nozzle tip.

• 한국연소학회:학술대회논문집
• /
• 2002.11a
• /
• pp.41-47
• /
• 2002

Oxygen has been used extensively in various industries for many years. Despite earlier successful attempts to use oxygen in industrial combustion furnaces, its full theoretical researches have only recently begun to be realized. The aim of this study is to investigate the effect of oxygen enriched combustion. This paper analyzes the characteristics of oxygen enriched combustion, and deals with the experimental investigation of the flame temperature and NOx concentration in exhaust gas. The flame temperature, concentration of exhaust gas were measured and flame configurations were photographed according to the variation of oxygen concentrations in oxidizer.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.11a
• /
• pp.258-262
• /
• 2011

The laminar burning velocity in premixed Oxy-CH4 flames was studied in a lab-scale Bunsen burner. $CH^*$ chemiluminescence method and Schliren photography were used. Experimental results were compared with numerical prediction which was calculated with a CHEMKIN 3.7 package with a PREMIX code. Global equivalence ratio of oxy-CH4 mixture was varied from 0.5 to 2.0 in a laminar flow region. The laminar burning velocity was measured as 3.1 m/s for Schlieren photograph and 2.9 m/s for $CH^*$ chemiluminescence technique (angle method).

• Clean Technology
• /
• v.27 no.1
• /
• pp.93-103
• /
• 2021

As the seriousness and necessity of responding to climate change and reducing carbon emissions increases, countries around the world are continuing their efforts to reduce greenhouse gases. Among various efforts, research on CCUS, capturing and utilizing carbon dioxide generated when using carbon-based fuels, is actively being conducted. Studies on pressurized oxy-fuel combustion (POFC) that can be used with CCUS are also being conducted by many researchers. The purpose of this study is to analyze basic information related to the flame structure and pollutant emissions of pressurized oxy-fuel combustion. For this, a counter-flow diffusion flame model was used to analyze the combustion characteristics according to pressure and oxygen concentration. As the pressure increased, the flame temperature increased and the flame thickness decreased due to a reaction rate improvement caused by the activation of the chemical reaction. As oxygen concentration increased, both the flame temperature and the flame thickness increased due to an improvement to the reaction rate and diffusion because of a change in oxidizer momentum. Analyzing the related heat release reaction by dividing it into three sections as the oxygen concentration increased showed that the chemical reaction from the oxidizer side was subdivided into two regions according to the mixture fraction. In addition, the emission index of NO classified according to the NO formation mechanism was analyzed. The formation trend of NO according to each analysis condition was presented.

• Journal of Advanced Marine Engineering and Technology
• /
• v.35 no.6
• /
• pp.814-819
• /
• 2011

An Oxy-fuel combustion has been studied in order to reduce exhaust emissions and fuel consumption. The flow and flame behaviors are analyzed with focal length variation in one-focussing oxygen burner introduced in this study. Oxygen is supplied into the center of the nozzle, methane fuel is into the outer nozzle of the center, and then oxygen is again supplied into the outer of the fuel nozzle. The test conditions are 5 focal lengths of 100mm to 500mm. The mixing behaviors and temperature distributions are analyzed. The result shows that the shorter the focal length is, the longer the mixing length becomes, and the flame width and length are the biggest in the case of 300mm.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.28 no.7
• /
• pp.275-282
• /
• 2016

MILD (Moderate and Intense Low-oxygen Dilution) combustion using oxygen as an oxidizer is considered as one of the most promising combustion technologies for high energy efficiency and for reducing nitrogen oxide and carbon dioxide emissions. In order to investigate the effects of nozzle angle and oxygen velocity conditions on the formation of oxygen-MILD combustion, numerical and experimental approaches were performed in this study. The numerical results showed that the recirculation ratio ($K_V$), which is an important parameter for performing MILD combustion, was increased in the main reaction zone when the nozzle angle was changed from 0 degrees to 15 degrees. Also, it was observed that a low and uniform temperature distribution was achieved at an oxygen velocity of 400 m/s. The perfectly invisible oxy-MILD flame was observed experimentally under the condition of a nozzle angle of $10^{\circ}$ and an oxygen velocity of 400 m/s. Moreover, the NOx emission limit was satisfied with NOx regulation of less than 80 ppm.

• Particle and aerosol research
• /
• v.4 no.2
• /
• pp.51-67
• /
• 2008

In this study, we devoted to kinetic measurement of the catalytic oxidation of iron-containing flame soot particles and better understanding the role of catalytic particles on carbon oxidation in particular at low temperature, targeting on autothermal regeneration of diesel particulate filter by diesel exhaust gas. Carbon-based Fe-containing particles generated by spraying ferrocene-doped diesel fuel in an oxy-hydrogen flame are tested and compared with a commercial carbon black powder for thermogravimetric analysis (TGA), secondary ion mass spectrometry (SIMS), Fourier-transform infrared spectroscopy (FTIR), Induced coupled plasma-Atomic emission spectroscopy (ICP-AES), and High-resolution transmission electron microscopy (HR-TEM). As a result, we found that a small amount of the ferrocene addition led to significant reductions in a on-set temperature and an activation energy of the carbon oxidation as well. An oxygenated surface complex forming at the particle surface could be thought as active species that would be readily consumed in particular at low temperature.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 2006.05a
• /
• pp.412-419
• /
• 2006

An Experimental study was conducted on $CO_{2}$ recycle combustion heating system using pure oxygen instead of conventional air as an oxidant, which is thereby producing a flue gas of mostly $CO_{2}$ and water vapor($H_{2}O$ and water vapor($H_{2}O$) and resulting in higher $CO_{2}$ concentration. The advantages of the system are not only the ability to control high temperatures characteristic of oxygen combustion with recycling $CO_{2}$ but also the possibility to reduce NOx emission in the flue gas. A small scale industrial reheating furnace simulator and specially designed variable flame burner were used to characterize the $CO_{2}$ recycle oxy-fuel combustion, such as the variations of furnace pressure, temperature and composition in the flue gas during recycle. It was found that $CO_{2}$ concentration in the flue gas was about 80% without $CO_{2}$recycle. The furnace temperature and pressure and pressure were decreased due to recycle and the NOx emission was also reduced to maintain under 100ppm.