Korean Chemical Engineering Research

  • 제52권2호
  • /
  • Pages.233-239
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  • 2014
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  • 0304-128X(pISSN)
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  • 2233-9558(eISSN)
한국화학공학회 (The Korean Institute of Chemical Engineers)
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TMA를 이용한 국내 발전용 탄의 용융점 변화에 대한 연구

A Study on Ash Fusibility Temperature of Domestic Thermal Coal Implementing Thermo-Mechanical Analysis

  • 이순호 (부산대학교 기계공학부 에너지변환시스템연구실/화력발전에너지 분석기술센터) ;
  • 임호 (부산대학교 기계공학부 에너지변환시스템연구실/화력발전에너지 분석기술센터) ;
  • 김상도 (한국에너지기술연구원 청정석탄센터) ;
  • 전충환 (부산대학교 기계공학부 에너지변환시스템연구실/화력발전에너지 분석기술센터)
  • Lee, Soon-Ho (Energy Conversion System Lab/Pusan Clean Coal Center, Department of Mechanical Engineering, Pusan National University) ;
  • Lim, Ho (Energy Conversion System Lab/Pusan Clean Coal Center, Department of Mechanical Engineering, Pusan National University) ;
  • Kim, Sang Do (Clean Coal Center, Korea Institure of Energy Research) ;
  • Jeon, Chung-Hwan (Energy Conversion System Lab/Pusan Clean Coal Center, Department of Mechanical Engineering, Pusan National University)
  • 투고 : 2013.11.01
  • 심사 : 2014.01.09
  • 발행 : 2014.04.01
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초록

석탄 연소 시 발생하는 회가 보일러 벽면에 부착되어 일어나는 슬래깅 현상은 보일러의 열효율을 감소시키고 보일러 안정성에도 악영향을 준다. 이러한 슬래그의 유동 특성은 회의 용융 특성과 관련이 있는데 이는 회의 화학적 조성에 영향을 받는다. 본 연구에서는 회의 용융특성을 TMA(Thermo-Mechanical Analysis) 장비를 이용하여 분석하였다. 이 테스트는 회의 수축률에 따른 용융온도(T25%, T50%, T75%, T90%)를 정량적으로 측정 하는 방법이다. TMA에서 측정된 각각의 온도는 용융단계별 특성을 나타낸다. TMA로 분석된 결과 값에 XRF 장비를 이용하여 분석한 회의 성분 조성이 미치는 영향을 분석하였다. 회에 포함된 성분 중 refractory, fluxing contents가 회분의 용융온도에 미치는 영향을 확인할 수 있었다. Refractory contents 성분인 $SiO_2$, $Al_2O_3$의 함량이 많을수록 전체적인 용융온도가 올라가며 $SiO_2/Al_2O_3$가 커질수록 고온에서의 용융온도인 T75%, T90%가 낮아지는 것을 알 수 있었다. 이와 달리 fluxing contents 성분인 $Fe_2O_3$, $K_2O$, CaO의 함량이 많아질수록 전체적인 용융온도가 낮아지며 이중 $K_2O$, CaO는 초기 용융 온도인 T25%를 낮추는데 큰 역할을 하는 것으로 판단되었다. TMA 분석과 회의 조성 비교를 통하여 회의 용융 특성을 예측하고 설명할 수 있었다.

The slagging which generated from ash deposition on furnace wall and tube in boiler reduces the heat transfer efficiency and damages to safety of boiler. The slag flow behavior in boiler is affected by melting temperature which is related to ash compositions. In this study, the behavior of slag is researched by using ash fusibility test, called TMA (Thermo-Mechanical Analysis). The technique measures the percentage shrinkage as the function of temperature, T25%, T50%, T75%, T90%. These temperatures indicate different stages of melting. Then, the effect of ash chemical compositions measured from XRF (X-ray Fluorescence Spectrometer) to ash fusion temperatures is discussed. Among the chemical compositions, refractory and fluxing influence on ash fusibility is described. High levels of refractory component and limited amount of fluxing components ($Fe_2O_3$, $K_2O$, CaO) increase overall melting temperatures. High $SiO_2/Al_2O_3$ ratio decrease high melting temperatures (T75%, T90%). Meanwhile, the presence of reasonable levels of fluxing components reduces overall melting temperature. A presence of fluxing component such as $K_2O$ and CaO is found to decrease the T25% values significantly. From this research, it is possible to make a reasonable explanation and prediction of ash fusion characteristic from analysis of TMA results and ash chemical compositions.

키워드

참고문헌

  1. Choi, B. C., Kim, H. T. and Chun, W. G., "A Study on the Slagging Behavior with Various Composition of Coal Ash," Journal of Energy Engineering, 8(3), 445-451(1999).
  2. Korea Electric Power Cooperation, Combustion Management Practices, Korea Power Learning Institute(1998).
  3. Couch, G. R., Understanding Slagging and Fouling in Pf Combustion, IEA Coal Research, London(1994).
  4. Scott D. H., Ash Behaviour during Combustion and Gasification, IEA Coal Research, London(1999).
  5. Mohanty, D. K. and Singru, P. M., "Numerical Method for Heat Transfer and Fouling Analysis of a Shell and Tube Heat Exchanger using Statistical Analysis," Korean J. Chem. Eng., 29(9), 1144-1150(2012). https://doi.org/10.1007/s11814-012-0003-6
  6. Tomeczek, J., Coal Combustion, Krieger Pub Co., Malabar, FL(1994).
  7. Park, H. Y., Kim, E. H., Kim, Y. J., Im, H. S., Kim, K. S. and Lee, J. E., "Advanced Slagging Propensity of Coal and its Assessment with the Conventional Indices," Journal of Energy Engineering, 21(4), 427-434(2012). https://doi.org/10.5855/ENERGY.2012.21.4.427
  8. Park, Y. K. and Oh, M. S., "Prediction of Tcv for Coal Slags under Reducing Condition," Korean Chem. Eng. Res.(HWAHAK KONGHAK), 44(6), 623-630(2006).
  9. Vassilev, S. V., Kitano, K., Takeda, S. and Tsurue, T., "Influence of Mineral and Chemical Composition of Coal Ashes on their Fusibility," Fuel Process. Technol., 45, 27-51(1995). https://doi.org/10.1016/0378-3820(95)00032-3
  10. Standards Association of Australia, Coal and Coke Analysis and Testing, Part 15: Higher Rank Coal Ash and Coke Ash fusibility, 3rd ed., Standards Australia, Homebush, NSW(1995).
  11. Rushdi, A., Sharma, A. and Gupta, R., "An Experimental Study of the Effect of Coal Blending on Ash Deposition," Fuel, 84, 495-506(2004).
  12. An, K. J., Lee, B. H., Kim, S. I. and Jeon, C. H., "Study on Slagging Characteristic of Hybrid Coals using the Thermo-Mechanical Analysis," Spring conference on KSME, May, Yeongheung(2013).
  13. Gupta, S. K., Wall, T. F., Creelman, R. P. and Gupta, R. P., "Ash Fusion Temperatures and the Transformations of Coal Ash Particles to Slag," Fuel Process. Technol., 56, 33-43(1998). https://doi.org/10.1016/S0378-3820(97)00090-8
  14. Huggins, F. E., Kosmack, D. A. and Huffman, G. P., "Correlation between Ash-Fusion Temperatures and Ternary Equilibrium Phase Diagrams," Fuel, 60, 577-584(1981). https://doi.org/10.1016/0016-2361(81)90157-5
  15. Gupta, R. P., Wall, T. F. and Baxter, L., Impact of Mineral Impurities in Solid Fuel Combustion, Kluwer Academic/Plenum Publishers, New York, NY(1999).
  16. Lowry, H. H., Chemistry of Coal Utilization, J. Wiley & Sons, New York, NY(1947).

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  2. Steam Reforming of Toluene Over Ni/Coal Ash Catalysts: Effect of Coal Ash Composition vol.59, pp.2, 2014, https://doi.org/10.9713/kcer.2021.59.2.232