Combustion and reaction

Restart-up Performance of a CFB Boiler after a Sudden Power Failure Accident

  • YAO Yuge ,
  • JIANG Ling ,
  • XIAO Huiren ,
  • DENG Boyu ,
  • ZHANG Man ,
  • ZHANG Yang ,
  • YANG Hairui ,
  • LYU Junfu
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  • Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China

Online published: 2023-12-01

Supported by

This research was supported by National Natural Science Foundation of China (U1710251).

Copyright

Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag GmbH Germany, part of Springer Nature 2022

Abstract

Due to the massive bed materials in its typical main loop, a circulating fluidized bed (CFB) boiler may face greater trouble in operation and restart-up if an unplanned sudden power failure happens in the power plant. This study aims to explore the restart-up performance of a 170 t/h natural circulation CFB boiler after a sudden power failure and evaluate whether the hot restart-up can be realized. The heat transfer process after the restoration of the primary air is modeled. Validating the isothermal property of the bed after the restoration of the power and air supply, the correlation among the accident duration time, bed temperature after the power restores, inlet air temperature, air supply time, and air velocity is proposed. The predicted results indicate that the major influencing factor of the bed temperature during this process is primary air velocity. To provide guidelines for judgment on whether the hot restart-up can be realized, the maximum values of the air supply time and accident duration time for hot restart-up for different types of coals are given. The results show both of them have a rapid decrease as the coal ignition temperature in a CFB boiler increases from 450°C to 650°C, which also means that the coal ignition temperature plays a very important role in the restart-up process. Based on the simulation results of bed temperature during the accident, it is also estimated that the drum level drops by 77.7 mm after 8 hours but still stays in the permissible range.

Cite this article

YAO Yuge , JIANG Ling , XIAO Huiren , DENG Boyu , ZHANG Man , ZHANG Yang , YANG Hairui , LYU Junfu . Restart-up Performance of a CFB Boiler after a Sudden Power Failure Accident[J]. Journal of Thermal Science, 2022 , 31(3) : 830 -839 . DOI: 10.1007/s11630-022-1585-x

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