Heat Transfer Model and Energy Dissipation Rate in Bubble Columns with Continuous Operation

연속조작 기포탑에서 열전달 모델 및 에너지 소멸 속도

  • Jang, Ji Hwa (School of Chemical Engineering, Chungnam National University) ;
  • Seo, Myung Jae (School of Chemical Engineering, Chungnam National University) ;
  • Lim, Dae Ho (School of Chemical Engineering, Chungnam National University) ;
  • Kang, Yong (School of Chemical Engineering, Chungnam National University) ;
  • Jung, Heon (Synfuel Research Group, KIER) ;
  • Lee, Ho Tae (Synfuel Research Group, KIER)
  • 장지화 (충남대학교 화학공학과) ;
  • 서명재 (충남대학교 화학공학과) ;
  • 임대호 (충남대학교 화학공학과) ;
  • 강용 (충남대학교 화학공학과) ;
  • 정헌 (한국에너지기술연구원 합성연료센터) ;
  • 이호태 (한국에너지기술연구원 합성연료센터)
  • Received : 2009.07.13
  • Accepted : 2009.08.21
  • Published : 2009.10.31

Abstract

Heat transfer model and energy dissipation rate were investigated to examine the heat transfer mechanism in bubble columns with continuous operation. The energy dissipation rate($E_D$) obtained from the unsteady state heat transfer model based on the surface renewal theory was significantly small, comparing with the hydrodynamic energy dissipation rate($P_v$) calculated from the overall hydrodynamic energy balance based on the behaviors and holdups of gas and liquid phases in the column. It was found from these results that the energy dissipation rate based on the surface renewal theory is independent of the hydrodynamic energy dissipation rate obtained from the overall hydrodynamic energy balance in the bubble column, in considering their mechanism. The different two energy dissipation rates were correlated in terms of operating variables within this experimental conditions, respectively.

연속조작 기포탑에서 열전달 메카니즘을 검토하기 위하여 열전달 모델과 에너지 소멸속도를 고찰하였다. 기포탑에서 표면갱신이론(Surface renewal theory)에 기초한 비정상상태 열전달모델에 의한 에너지소멸 속도($E_D$)는 기포탑에서 기체와 액체상의 거동에 의한 수력학적인 에너지소멸 속도($P_v$)와 비교하여 매우 작게 나타났다. 이와같은 결과로 표면갱신 이론에 의한 비정상상태 열전달모델에서 사용된 에너지 소멸속도와 기포탑 전체에 대한 수력학적 에너지 수지에 의해 산출된 수력학적 에너지 소멸속도는 산출 메카니즘이 서로 다른 별개의 에너지 소멸속도로 규명되었다. 이들 두 종류의 에너지 소멸속도를 각각 본 연구의 실험 변수인 기체와 액체 유속의 상관식으로 나타내어 완전히 다른 값을 나타냄을 확인하였다.

Keywords

Acknowledgement

Supported by : 한국에너지기술연구원

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