• Journal of Energy Engineering
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• v.24 no.3
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• pp.82-88
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• 2015

After a reheating furnace installation, the modification of the size and the heat capacity is very difficult. Therefore, the development of design package tool is required for the computation on the correct specifications before the design and the installation. Prior to development of the design tool, a module that calculates the amount of heat loss of each part according to the specifications for determining the thermal efficiency of a continuous heating furnace was developed and applied to the oxy-fuel industrial furnace. Through this, the effects of fuel type, oxygen fraction and recirculation on the efficiency of the furnace of which the output is 110Ton/hour were analyzed. In oxy-fuel combustion condition, the efficiency was 15% higher than air combustion conditions. With the using COG(Coke Oven Gas) instead of LNG, the efficiency was slightly increased. In the air combustion condition, the efficiency was increased about 33% with the preheated air. But, in oxy-fuel condition, the amount of exhaust gas was reduced, so the efficiency was increased about 7%.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.11 s.242
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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.

• 한국연소학회:학술대회논문집
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• 2012.04a
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• pp.213-215
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• 2012

As one of the primary fuel sources, oxy-fuel combustion of coal is actively being investigated because of the climate changing problem such like the emission of green house gases. In this paper research about the pulverized coal technology, which is widely used in both power-generating and iron-making processes was studied to invesgate the ignition behaviour of pulverized coal particles during coal combustion as changing the ambient oxygen concentration of the particle. The ignition phenomenon of the coal particles fed into a laminar flow reactor was imaged with a Integrated charged-coupled device (ICCD) camera. The ignition points were determined throught the analysis of the images, and then the ignition delay times were able to be calculated. The experiment results show that a lower oxygen concentration increases the ignition delay time.

• Korean Chemical Engineering Research
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• v.59 no.3
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• pp.417-428
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• 2021

The combustion characteristics of anthracite, which follow a complex process with low reactivity, must be considered through the dynamic behavior of circulating fluidized bed (CFB) boilers. In this study, computational fluid dynamics (CFD) simulation was performed to analyze the combustion characteristics of anthracite in a pilot scale 0.1 MW_th Oxy-fuel circulating fluidized bed (Oxy-CFB) boiler. The 0.1MW_th Oxy-CFB boiler is composed of combustor (0.15 m l.D., 10 m High), cyclone, return leg, and so on. To perform CFD analysis, a 3D simulation model reactor was designed and used. The anthracite used in the experiment has an average particle size of 1,070 ㎛ and a density of 2,326 kg/m³. The flow pattern of gas-solids inside the reactor according to the change of combustion environment from air combustion to oxygen combustion was investigated. At this time, it was found that the temperature distribution in air combustion and oxygen combustion showed a similar pattern, but the pressure distribution was lower in oxygen combustion. addition, since it has a higher CO₂ concentration in oxygen combustion than in air combustion, it can be expected that carbon dioxide capture will take place actively. As a result, it was confirmed that this study can contribute to the optimized design and operation of a circulating fluidized bed reactor using anthracite.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.123-123
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• 2014

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.10a
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• pp.432-434
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• 2008

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

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2940-2945
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• 2008

The scale of 2.4 MW MCFC was taken to construct a high-efficiency and economical power generation system without CO2 emission into the atmosphere for utilizing its exhaust gas. The conventional steam turbine power generation system (STGS) was evaluated and the net generated power (NGP) was estimated to be only 133 kW and the STGS is not economically feasible. A CO2-caputuring repowering system was proposed, where low temperature steam (LTS) produced at HRSG by using exhaust gas from MCFC is utilized as a main working fluid of a gas turbine, and the temperature of LTS was raised by combusting fuel in a combustor by using pure oxygen, not the air. It has been shown that NGP of the proposed system is 264 kW, and CO2 reduction amount is 608 t-CO2/y, compared to 306 t-CO2/y of STGS. The CO2 reduction cost was estimated to be negligible small, even when the costs of oxygen production and CO2 liquefaction facilities etc. were taken into account.

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

• Proceedings of the KSME Conference
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• 2008.11b
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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.