• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2971-2976
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• 2008

Recently, there has been growing interest in the oxyfuel combustion cycle since it enables high-purity CO2 capture with high efficiency. However, the oxyfuel combustion cycle has some important issues regarding to its performance such as the requirement of water recirculation to decrease a turbine inlet temperature and proper combustion pressure to enhance cycle efficiency. The purpose of the present study is to analyze performance characteristics of the oxyfuel combustion cycle with different turbine inlet temperatures and combustion pressures. It is expected that the turbine inlet temperature improves cycle efficiency, on the other hand, the combustion pressure has specific value to display highest cycle efficiency.

• 한국유체기계학회 논문집
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• 제12권4호
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• pp.30-36
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• 2009

Recently, there has been growing interest in the oxyfuel combustion cycle since it enables high-purity $CO_2 capture with high$ efficiency. However, the oxyfuel combustion cycle has some important issues regarding to its performance such as the requirement of water recirculation to decrease a turbine inlet temperature and proper combustion to enhance cycle efficiency. Also, Some of water vapour remain not condensed at condenser outlet because cycle working fluid contains non-condensable gas, i.e., $CO_2$. The purpose of the present study is to analyze performance characteristics of the oxyfuel combustion cycle with different turbine inlet temperatures, combustion pressures and condenser pressure. It is expected that increasing the turbine inlet temperature improves cycle efficiency, on the other hand, the combustion pressure has specific value to display highest cycle efficiency. And increasing condensing pressure improves water vapour condensing rate.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
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• pp.118-123
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• 2004

The combustion characteristics of 0.03MW turbulent methane/oxygen diffusion flames have been investigated to give basic informations for designing industrial oxyfuel combustors. NOx reduction has become one of the most determining factors in the combustor design since 3-5% nitrogen is intrinsically included from the current oxygen producing processes. Flame lengths and NOx concentrations were measured by varying flow velocities with and without installing quarls. Flame stabilities are significantly enhanced by oxyfuel combustion in contrast to air-fuel combustion. Flame length decreases with increasing fuel or oxygen velocity because of the enhancement of turbulent mixing. NOx concentration was reduced with increasing flo velocities. This can be attributed to the entrainment of inert product gases into flame decreasing flame temperature. The installation of quarl on the burners rather increased NOx concentration since the quarl blocked the entrainment above the nozzles.

• 한국수소및신에너지학회논문집
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• 제21권6호
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• pp.553-560
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• 2010

The characteristics of syngas-oxyfuel combustion has been investigated experimentally in the present study. Experimental measurements were conducted to aid a fundamental design of a syngas-oxyfuel combustor with a double coaxial burner configuration. To examine the effects of different syngas fuels on combustion characteristics, various fuel types are utilized such as commercial coal gases (Texaco, Shell), COG (cokes oven gas), and $CH_4$ as a main component of natural gas. $CO_2$ was added to the four fuel types as a diluent gas to reduce the flame temperature. The flame images and emission characteristics of NOx and CO were examined for various equivalence ratio and $CO_2$ dilution ratio. The results show that CO emission was rapidly increased as equivalence ratio approached the stoichiometry condition by reducing the amount of oxygen. As the $CO_2$ dilution increased, CO emission increased while NOx emission decreased due to reduced flame temperature. When the syngas-oxyfuel combustor is operated with 20~40% of $CO_2$ dilution ratio, the CO and NOx emission levels were kept below 50 ppm and 25 ppm, respectively, with a high concentration of $CO_2$ over 95 vol.% in exhaust gases.

• 한국가시화정보학회지
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• 제2권1호
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• pp.3-7
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• 2004

Two novel industrial combustion technologies are introduced. High temperature air regenerative combustion for industrial heating system and oxyfuel combustion for power plant are considered as a energy saving and $CO_{2}$ emission reducing combustion technology. Research works are necessary to understand fundamental phenomena and to develope application technologies to industrial sector.

• Bulletin of the Korean Chemical Society
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• 제35권6호
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• pp.1613-1618
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• 2014

Perovskite-type oxides are promising oxygen carriers in producing oxygen-enriched $CO_2$ gas stream for oxyfuel combustion. In this study, a new series of $SrCo_{1-x}Fe_xO_{3-{\delta}}$ (x = 0.2, 0.4, 0.6, 0.8) was prepared and used to produce $O_2/CO_2$ mixture gas. The phase, crystal structure, and morphological properties of $SrCo_{1-x}Fe_xO_{3-{\delta}}$ were investigated through X-ray diffraction, specific surface area measurements, and environmental scanning electron microscopy. The oxygen desorption performance of $SrCo_{1-x}Fe_xO_{3-{\delta}}$ was studied in a fixed-bed reactor system. Results showed that the different x values of $SrCo_{1-x}Fe_xO_{3-{\delta}}$ have no obvious effects on crystalline structure. However, the oxygen desorption performance of $SrCo_{1-x}Fe_xO_{3-{\delta}}$ is improved by Co doping. Moreover, $SrCo_{0.8}Fe_{0.2}O_{3-{\delta}}$ synthesized via a new EDTA method has a larger BET surface area ($40.396m^2/g$), smaller particle size (48.3 nm), and better oxygen production performance compared with that synthesized through a liquid citrate method.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 동계학술발표대회 논문집
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• pp.81-81
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• 2006

• 대한기계학회논문집B
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• 제37권5호
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• pp.481-488
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• 2013

10 %의 암모니아가 첨가된 메탄 연료의 비예혼합 확산화염에서, 산소/이산화탄소 및 산소/질소의 산화제 내에 산소 비율의 변화에 따른 질소산화물($NO_x$)의 생성 특성을 실험 및 수치해석적으로 조사하였다. 동축류 제트 화염의 실험에서, 산소/이산화탄소의 산화제인 경우, 측정된 $NO_x$은 산소 비율의 증가에 따라 약간 증가하는 경향을 보였다. 반면에, 산소/질소의 산화제인 경우, $NO_x$은 0.7의 산소 비율에서 최대로 측정되었으며, 산소 비율에 따라 비단조적인 경향을 보였다. 결과적으로, 암모니아가 첨가된 메탄 화염에서 배출되는 $NO_x$는 일반 공기의 조건보다 순산소 연소 조건의 경우가 더 크게 측정되었다. 한편, 다양한 산화제의 조건에 대하여 $NO_x$ 생성 특성을 분석하기 위해서, 동일한 화학반응 메커니즘을 적용하여 1 차원 및 2 차원의 수치해석을 수행하였다. 그 결과, 산소/질소의 산화제에서 2 차원의 수치해석 결과가 실험적으로 측정된 $NO_x$의 배출 특성을 비교적 잘 예측하였다.

• 대한기계학회논문집B
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• 제29권11호
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• pp.1277-1284
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• 2005

The combustion characteristics of methane oxygen diffusion flames have been investigated to give basic information for designing industrial oxyfuel combustors. NOx reduction has become one of the most determining factors in the combustor design since the small amount of nitrogen is included from the current low cost oxygen production process. Flame lengths decreased with increasing fuel or oxygen velocity because of the enhancement of mixing effect. Correlation equation between flame length and turbulent kinetic energy was proposed. NOx concentration was reduced with increasing fuel or oxygen velocity because of the enhanced entrainment of the product gas into flame zone as well as the reduction of residence time in combustion zone.

• 한국연소학회지
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• 제16권2호
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• pp.1-8
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• 2011

As one of the main technologies for carbon capture and storage in power generation, oxy-coal combustion is being developed for field demonstration in Korea. This study presents the results of numerical simulation for combustion in a single-wall-fired 100 $MW_e$-scale boiler proposed for the initial design of the demonstration plant. Using a commercial CFD code, the detailed combustion, flow and heat transfer characteristics were assessed both for air-mode and oxy-mode combustion. The results show that stable combustion can be achieved in the dual mode operation with the current boiler configuration. However, the differences in the flow pattern and heat transfer between the two combustion modes need to be considered in the design and operation which is mainly due to the larger density and specific heat of $CO_2$ compared to $N_2$. Further development of the boiler design is required using improved numerical modeling for radiative heat transfer and combustion.