Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
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Analysis of Density Wave Oscillation in Boiler Furnace Wall Tubes with Parallel Channel Modeling

평행관 모델링을 통한 보일러 화로벽관 내 밀도파 불안정의 해석

  • Kim, Jinil (System Engineering Team, Corporate R&D Institute, Doosan Heavy Industries and Construction) ;
  • Choi, Sangmin (Dept. of Mechanical Engineering, Korea Advanced Institute of Science and Technology)
  • 김진일 (두산중공업(주) 기술연구원 시스템엔지니어링팀) ;
  • 최상민 (KAIST 기계공학과)
  • Received : 2012.08.30
  • Accepted : 2012.10.08
  • Published : 2013.02.01
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Abstract

A numerical model was developed to predict the density wave oscillation (DWO) in the furnace wall tubes of a fossil-fired once-through boiler. The transient flow fields in the tubes were obtained using a 1D finite volume method in the time domain. A header model was also implemented to simulate the parallel tube connection of the wall tubes. The inlet and outlet mass flow variation in one of the parallel tubes was examined after a heat perturbation to find the DWO. After successful verification with experimental results reported in literature, the developed model was applied to the wall tubes of a 700-MW boiler furnace. In contrast to the simulation of Takitani's experiment, in which the unstable power thresholds tended to rise in the reduced bypass channel flow, no remarkable changes were observed in the power thresholds in the parallel channel modeling of the wall tubes of the boiler furnace.

화력발전용 관류보일러 화로벽관에서의 밀도파 불안정 예측을 목적으로 수치모델을 개발하였다. 시간 도메인에서 1 차원 유한체적법을 적용하여 관내 비정상상태의 유동장을 계산하였으며, 화로벽관의 평행관 연결을 모사하기 위해 헤더의 모델도 포함하였다. 평행관들 가운데 하나의 관에 열 섭동을 부가 후 관 입출구 유량의 변동을 관찰함으로써 밀도파 불안정을 찾았다. 개발된 모델은 문헌의 실험결과와 검증을 거쳐 700MW 보일러 화로벽관에 적용하였다. 그 결과 Takitani 의 실험결과에서는 평행으로 연결된 우회 유량이 줄어들수록 불안정 경계 열량이 상승하는 경향이 있었던 반면, 보일러 화로벽관의 경우에는 평행관 모델링에 크게 영향을 받지 않음을 확인하였다.

Keywords

References

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