• Plant Journal
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• v.18 no.1
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• pp.55-61
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• 2022

In this study, I analyzed the effect of slagging caused by blending bituminous coal and subbituminous coal while maintaining the generator output, combustion conditions, and ventilation conditions for 870MW thermal power plant designed with bituminous coal. Accordingly I proposed an acceptable method of blending coal method. the blending ratio of sub-bituminous coal was adjusted to 10%, 20%, 40%, 60%, 80%, etc. to confirm ultimate analysis, proximate analysis, ash fusion temperature change, slagging indices, etc. Proper blending coal conditions are blending with sub-bituminous coal at 40% or less, ratio of base component to acid component(B/A) is 0.4 or less or 1 or more, total alkali(TA) is 3.5 or less, fusion slagging index(Rfs) is 1,345℃ or more, and ash content is 13% or less in ultimate analysis, the ash content in proximate analysis is 15% or less, and the initial deformation temperature(IDT) should be at least 1,200℃ or more

• Journal of Energy Engineering
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• v.4 no.3
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• pp.324-330
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• 1995

석탄 연소로에 사용 적합한 석탄의 선정 및 조업조건의 설정에 도움을 주고, 석탁회분의 슬래깅 성향을 파악하기 위해서 갈탄부터 역청탄에 이르는 4종의 시료를 사용하여 산화성 분위기에서 고온 회전 점도계를 사용하여 석탄회분 슬래그의 점도를 온도의 함수로서 측정하였다. 또한 석탄회분의 슬래깅 성향을 해석하기 위해서, 석탄회분 조성을 사용한 Base/Acid Ratio, Lignite Factor 및 Silica Ratio 등의 주요한 인자들이 슬래그 점도에 미치는 영향을 고찰하였다.

• Journal of Energy Engineering
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• v.21 no.4
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• pp.427-434
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• 2012

The fuel characteristics and combustion behaviors of bituminous (Anglo) and sub-bituminous (Tanito) coals used in 500MW coal fired power plant have been investigated. With ashes of those coals, the ash fusibility is characterized with thermo mechanical analyzer, and the advanced ash slagging propensity, BHEL index, has been obtained. The melting-down of tanito coal ash happened in the temperature range of 1,200 to $1,250^{\circ}C$, and for anglo coal ash it occurred near $1,550^{\circ}C$. BHEL indices for two coals gives the high slagging propensity, and these are compared with the existing traditional indices which give different tendencies.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1996.10b
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• pp.113-122
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• 1996

본 연구는 석탄가스화복합발전(IGCC)의 핵심부분이라 할 수 있는 슬래깅 형태의 분류층 가스화기에 원활한 Slagging을 유지하기 위해 Flux addition method와 Coal blending method를 적용하였다. 대상탄으로는 가스화에 적합하다고 알려진 알라스카탄, 대동탄과 비교탄으로 가스화에 부적합하다고 알려진 1종류의 유연탄을 대상으로 기본분석 및 화학적 조성분석, 용융온도를 측정하여 봄으로써 대상탄들의 슬래깅성향을 평가하였다. 대동탄과 알라스카탄에 대해서는 Flux addition method를 적용하고, 비교탄에 대해서는 Coal blending Method를 적용한 후, 140$0^{\circ}C$로 운전되는 가스화기의 효율을 최대화할 수 있는 Flux 첨가비와 blending ratio를 산정하였다.

• Clean Technology
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• v.24 no.4
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• pp.323-331
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• 2018

The results of an experimental investigation on the co-firing characteristics and slagging behavior of dried and hydrothermal carbonization sewage sludge, sub-bituminous coal, and wood pellet in a fluidized bed were presented. Combustion tests were conducted in a lab-scale bubbling fluidized bed system at the uniform fuel-air equivalence ratio, air flow rate, and initial bed temperature to measure bed temperature distribution and combustion gas composition. 4 different fuel blending cases were prepared by mixing sewage sludge fuels with coal and wood pellet with the ratio of 50 : 50 by the heating value. $NO_x$ was mostly NO than $NO_2$ and measured in the range of 400 to 600 ppm in all cases. $SO_2$ was considered to be affected mostly by the sulfur content of the sewage sludge fuels. The cases of hydrothermal carbonization sewage sludge mixture showed slightly less $SO_2$ emission but higher fuel-N conversion than the dried sewage sludge mixing cases. The result of fly ash composition analysis implied that the sewage sludge fuels would increase the possibility of slagging/fouling considering the contents of alkali species, such as Na, K, P. Between the two different sewage sludge fuels, dried sewage sludge fuel was expected to have the more severe impact on slagging/fouling behavior than hydrothermal carbonization sewage sludge fuel.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2008.05a
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• pp.57-58
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• 2008

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.12
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• pp.1772-1780
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• 2003

An optimal soot blowing system has been developed for an optimal operation of power utility boilers by both minimization of the use of steam and the number of soot blowers worked during soot blowing. Traditionally, the soot blowing system has been operated manually by operators. However, it causes the reduction of power and thermal performance degradation because all soot blowers installed in the plant should be worked simultaneously even there are lots of tubes those are not contaminated by slagging or fouling. Heat transfer area is divided into four groups, furnace, convection area including superheater, reheater and economizer, and air preheater in the present study. The condition of cleanness of the tubes is calculated by several parameters obtained by sensors. Then, a part of soot blowers works automatically where boiler tubes are contaminated. This system has been applied in a practical power plant. Therefore, comparison has been done between this system and manual operation and the results are discussed.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.867-870
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• 2009

일반적으로 내화재의 내침식성은 크롬 함량이 증가함에 따라 향상되는 특성을 가지는데, 본 연구에서는 이러한 크롬 내화재의 물성을 보다 향상시키기 위하여 인산염 화합물인 $AlPO_4$를 첨가하는 실험을 진행하였으며, 이러한 실험 결과 선정된 $AlPO_4$ 1% 첨가 크롬 내화재를 대상으로 캐스타블 및 브릭 형태로 각각 제작하였을 때 내침식 특성에 대해 회전 침식 시험장치를 이용한 실험을 실시하였는데, 실험 결과 캐스타블에 비해 브릭 내화재가 내침식성이 우수하지만 일부 spalling이 발생하는 것으로 파악되었다. 그리고, 가스화기로의 석탄 공급 방식에 따라 내화재 벽면에서 발생하는 석탄입자에 의한 내화재 침식 정도에 대한 전산해석을 수행한 결과 top feeding에 비해 side feeding 방식이 내화재 전면에 걸쳐 침식 현상이 크게 발생할 것으로 예측되어 보다 크롬 함량이 많은 내화재를 선정해야 할 것으로 평가되었다.

• Clean Technology
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• v.23 no.3
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• pp.331-342
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• 2017

To estimate the combustion characteristics of sewage sludge and wood pellet, thermogravimetric analysis (TGA) was conducted. As TGA results, combustion characteristics of sewage sludge was worse than wood pellet. In ash fusion temperature (AFT) analysis, slagging tendency of sewage sludge is very high compared to wood pellet. And also, the bubbling fluidized bed reactor with a inner diameter 400 mm and a height of 4300 mm was used for experimental study of combustion characteristics fueled by sewage sludge and wood pellet. The facility consists of a fluidized bed reactor, preheater, screw feeder, cyclone, ash capture equipment and gas analyzer. The thermal input of sewage sludge cases were $54.5{\sim}96.5kW_{th}$, in case of wood pellet experiment, it was $96.1kW_{th}$. As experiment results, the $NO_x$ emission of sewage sludge was averagely about 10 times the $NO_x$ emission of wood pellet. And also CO emission of sewage sludge is about 3.5 times of wood pellet. Lastly as a result of analysis of captured ash in cyclone, the combustion efficiency of all cases were over 99%, but the potential for slagging/fouling was high at all cases by component analysis of ash.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.63-66
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• 2014