• 한국연소학회:학술대회논문집
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• 2012.04a
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• pp.35-36
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• 2012

Part load operation usually covers large periods of the total operation time on the economic ground and electricity demand in small-scale boilers. Performance analysis of part load behavior is very important for the purpose of boiler operation optimization. A simple thermal calculation approach is applied to predict performance of a pilot-scale circulating fluidized bed (CFB) boiler at part load operation. Verification has been carried out by comparing between calculation results an operation data of the boiler.

• 한국연소학회:학술대회논문집
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• 2002.06a
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• pp.204-211
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• 2002

Combustion experiments are carried out to obtain the fundamental data for application of a internally circulating fluidized bed combustor to the combustion of paper sludge wastes. Experimental parameters are identified as secondary air ratio, sludge weight and water contents. The secondary air ratio was varied from 0 to 20% and water content was 14%, 25%, 35%, 45%, 62% and sludge weight was 30g, 60g, 90g. As a result, carbon conversion ratio was higher than injection of primary air. Emission of CO and NOx reduced with an increase of secondary air injection.

• 한국연소학회:학술대회논문집
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• 2004.06a
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• pp.165-172
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• 2004

Co-incineration of coal and wastewater sludge was r;erfonn:rl in a O.lMWth bench scale circulating fluidized bed combustor(CFBC) Sludge was received from a wastewater treatment plant in a dye industrial complex in Busan. Metropolis. Moisture content of received sludge was 80%. Coal and sludge mixture was prepared with weight ratio of 90/10, 85/15 and 80/20. Co-combustion characteristics of the coal and sludge mixture demonstrated stable combustion conditions. Component analysis, incineration characteristics, boiler performance was measured before and after the test and application for commercial 59MWth CFBC boiler. The release of hazardous components such as $SO_2$ and Cl was suppressed by the presence of inherent minerals of Ca, Na, K in coal and sludge mixture. Pre-drying was not essential but it was recommended for the benefits of manageability of sludge.

• Applied Chemistry for Engineering
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• v.21 no.5
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• pp.553-558
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• 2010

To solve the problems of the low combustion activity of Korean anthracite and the abundant loss of unburned carbon in fly ash, pellet coal was fabricated from coal fines and fly ash, and the mixed combustion of coarse coal with the pellet coal was examined in the circulating fluidized bed combustor of a 0.1 MW scale test unit. In the combustion of the raw coal only, the significant amount of coal fines was entrained, resulting in overheat at the top of the combustor. With the coarse coal that most fines were eliminated, however, the combustion temperature was maintained stable. The mixed combustion of coarse and raw coals was also feasible even though it often went unstable. The mixed combustion of the coarse coal with the pellet coal was as stable as the coarse coal combustion, showing a promise that the combustion of the Korean anthracite in commercial circulating fluidized bed boilers could be further enhanced.

• Plant Journal
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• v.8 no.1
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• pp.73-80
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• 2012

The structure and combustion characteristics, and the economic feasibility of the circulating fluidized bed combustion(CFBC) boiler using low grade coal were introduced. The economic feasibility is evaluated by comparing a 500 MW CFBC boiler power plant using low grade coal and a pulverized combustion boiler power plant with high grade coal. As the result of the evaluation, the pulverized coal combustion boiler power plant has an internal rate of return of 12.95%, 1,395.9 billion Korean won of net present value, and 6.26 years of payback period. On the other hand, CFBC boiler power plant has an internal rate of return of 13.54%, 1,704.3 billion Korean won of net present value, and 6.02 years payback period. Therefore, the CFBC boiler power plant has better feasibility in all aspects, as 0.59% higher of internal rate of return, 308.4 billion Korean won of higher net present value and 0.24 year of shorter payback period.

• 한국연소학회:학술대회논문집
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• 2004.06a
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• pp.173-179
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• 2004

Combustion of refuse derived fuel(RDF) and refuse plastic fuel (RPF) was carried out in a lab-scale circulating fluidized bed. Experiment was investigated cold flow visualization. RDF was made by C & tech and RPF was made by KRS. The results include distribution of temperature in the combustion chamber, and concentrations of flue gas such as $O_2$, $CO_2$, CO, $NO_x$ and HCs Micro G.C(gas chromatograph) was employed to find out concentration of He Temperature distribution was different when RDF and RPF were burnt respectably. As air ratio became increased, $CO_2$, CO, and total of HCs emissions were decreased. According to the number of carbon atom of HCs, HC were classified as five kinds of HC.

• 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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• 2012.11a
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• pp.119-122
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• 2012

Circulating fluided bed(CFB) furnace which can use a variety of low-grade fuels because of high heat capacity and good mixing characteristic in its furnace have turned out to be effective system. There is no many research to predict performance considering total boiler system with water-steam side. Most of performance prediction model have focused on hydrodynamics or chemical mechanism in furnace. so, This study is aimed to develop performance prediction model which consider water-steam side.

• Journal of the Korean Society of Combustion
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• v.16 no.4
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• pp.16-22
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• 2011

The present paper discusses thermal design parameters of different sizes of circulating fluidized bed (CFB) boilers with capacities ranging from 2 MWe pilot scale boiler to a 600 MWe utility boiler. Physical boiler size and shape of furnace were identified and dimensional data have been summarized. By performing thermal design for each of the boilers, heat transfer surface area, furnace shape and size, and allocation of heat transfer surface for water-steam side heat absorption have been recalculated, and presented. Although boilers may have significantly different capacity, the facilities have common design parameters, when they are evaluated as basic thermal design processes. The significance of thermal design procedure is explicitly discussed.

• Resources Recycling
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• v.15 no.1 s.69
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• pp.58-65
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• 2006

A new technology for refused derive fuel(RDF) utilization in circulating fluidized bed is under development. The RDF is tested in a bench scale circulating fluidized bed(CFB) combustor and its burning characteristics were investigated and collected as design parameters. The combustions were controllable and the HCl emission which is most important toxic emission were below 150 ppm at the exit of the combustor. The differences between conventional coal homing circulating fluidized bed boiler and the exclusive RDF boiler were studied and commercial scale co-generation CFB for RDF was designed.