Journal of Energy Engineering (에너지공학)

The Korean Society for Energy (한국에너지학회)
권호 표지
DOI QR코드

DOI QR Code

Numerical Study on the Characteristics of Combustion and Emission in Pulverized Coal-fired Boiler for Using High Moisture Coal and Dry Coal

석탄화력보일러에서 고수분탄 및 건조석탄 사용에 따른 연소 및 배기배출 특성에 대한 전산해석 연구

  • Received : 2017.11.10
  • Accepted : 2017.12.13
  • Published : 2017.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

This study was performed to investigate the characteristics of combustion and emissions in pulverized coal fired boiler for using high moisture coal and dry coal through computational fluid dynamics(CFD). We validated this boiler model with performance data of the boiler. The results of flow characteristics showed that climbing speed of gases was increased as blending ratio of high moisture coal was increased. It can decrease a residence time of fuel in the furnace. And it influence coal combustion. The coal burnout and NOx generation in burner level were decreased as increasing blending ratio of high moisture coal. The gas temperature and NOx formation were increased after OFA level due to coal burnout delay.

본 연구에서는 석탄화력보일러에서 고수분탄 및 건조석탄 사용이 연소와 배기배출 특성에 미치는 영향에 대한 전산해석 연구를 수행하였다. 대상 보일러 설계 조건의 성능데이터를 기준으로 보일러 해석 모델 결과를 검증하였으며, 역청탄과 고수분탄 및 건조석탄을 혼소하는 조건에 대한 계산을 수행하였다. 고수분탄 혼소 비율이 높아질수록 가스 수직속도는 증가하였으며, 이는 연료의 노내 체류시간을 줄여 보일러 연소성에 영향을 미칠 것으로 판단된다. 건조석탄을 혼소할 경우 역청탄과 유사한 연소 및 배기배출 특성을 보였다. 고수분탄 혼소 비율이 높아질수록 수분영향에 의해 버너영역에서 연소반응 및 NOx 생성은 감소하였으며, OFA(Over-fire air) 이후에 가스온도와 NOx 생성이 높아지는 결과를 확인하였다.

Keywords

References

  1. BP, 2015, BP Statistical Review of World Energy June 2015, BP, pp.42
  2. IEA, 2014, Coal information 2014, International Energy Agency, pp.43-57
  3. Blaine W. Asay, L. Dcuglas Lahjaily and Paul O. Hdeman, 1983, Effect of Coal Moisture on Burnout and Nitrogen Oxide Formation, Combustion Science and Technology, Vol. 35, pp. 15-31 https://doi.org/10.1080/00102208308923701
  4. Bosoaga A., Panoiu N., Mihaescu L.. Backreedy R.I., Ma L., Pourkashanian M., Wiliams A., 2006, The Combustion of Pulverized Low Grade Lignite, Fuel, Vol. 85, pp. 1591-1598 https://doi.org/10.1016/j.fuel.2005.12.018
  5. Kim S. G., Lee S. H., Rhim Y. J., Choi H. K., Lim J. H., Chun D. H., and Yoo J. H., 2012, Drying Characteristic of High Moisture Coal using a Flash Dryer, Korean Chem. Eng. Res., Vol 50, No. 1, pp.106-111 https://doi.org/10.9713/kcer.2012.50.1.106
  6. Ahn S. G., Kim J. W., Kim G. B., Lee S. H. and Jeon C. H., 2016, Study on the Unburned Carbon and NOx emission of High Moisture Coal, KOSEE, Vol. , No. , pp. 0-00
  7. Sal Gollakata, 2007, Demonstration of a Lignite Fuel Enhancement System, NETL
  8. S. Badzioch and P. G. W. Hawksley, 1970, Kinetics of Thermal Decomposition of Pulverized Coal Particles, Ind. Eng. Chem. Process Design and Development, Vol. 9, pp. 521-530
  9. M. M. Baum and P. J. Street, 1971, Predicting the Combustion Behavior of Coal Particles, Combustion Science and Technology, Vol. 3, pp. 231-243 https://doi.org/10.1080/00102207108952290
  10. F. Winter, C. Wartha, G. Loer and H. Hofbauer, 1996, The NO and N2O Formation Mechanism during Devolatilization and Char Combustion under Fluidized Bed Conditions, In 26th Symposium (International) on Combustion, Vol. 26, No. 2, pp. 3325-3334
  11. ANSYS, 2016, ANSYS Fluent User's Guide, ANSYS Inc