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

The Korean Society of Mechanical Engineers (대한기계학회)
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Numerical Study of Gap Size Ratio Effect for Noncondensable Gas Ventilation in Condensers

응축기의 비응축 가스 배출 타입에 따른 틈 간격 비율의 영향에 대한 수치적 연구

  • Je, Jun-Ho (Dept. of Mechanical Engineering, Pohang University of Science and Technology) ;
  • Kim, Soo-Jea (Dept. of Mechanical Engineering, Pohang University of Science and Technology) ;
  • Choi, Chi-Woong (Chemistry Department, University of Wyoming) ;
  • Kim, Moo-Hwan (Division of Advanced of Nuclear Engineering, Pohang University of Science and Technology)
  • 제준호 (포항공과대학교 기계공학과) ;
  • 김수재 (포항공과대학교 기계공학과) ;
  • 최치웅 (와이오밍주립대학교 화학과) ;
  • 김무환 (포항공과대학교 첨단원자력공학부)
  • Received : 2011.07.27
  • Accepted : 2011.09.30
  • Published : 2012.01.01
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Abstract

A numerical analysis was carried out to estimate the effect of the gap size ratio on the performance of condensers under noncondensable gas ventilation using the porous medium approach (PMA). In the PMA, the details of the tube bundle in the condenser are considered to be those of a porous medium, and the flow resistance term is added in the momentum equation. Three-dimensional analysis of the condensation for a McAllister condenser was conducted with the PMA using Fluent and user-defined functions (UDFs). The gap size effect on the condensation was negligible under pure steam conditions. However, the gap size effect was dominant in condensation with noncondensable gas and external venting. As the gap size decreased, the condensation rate increased for noncondensable gas in an external venting system.

본 논문은 응축기의 비 응축 가스 배출 타입에 따른 틈 간격의 비율이 응축기의 성능에 미치는 영향에 관하여 다공성 매질 개념을 적용한 수치적 연구에 관한 것이다. 다공성 매질의 개념을 이용한 응축기의 성능 해석에서는 응축기기 내부의 다관군을 다공성 매질로 간주하며, 다관군에 의한 압력 강하는 상관식으로 반영한다. 상용수치해석 프로그램인 Fluent 와 user-defined functions 를 이용하여 McAllister 응축기에 다공성 매질 개념을 적용하여 3 차원 응축량을 해석하였다. 순수증기의 해석에서는 틈 간격이 응축량에 미치는 영향이 거의 없었다. 그러나 비 응축가스가 포함되어 있으며, 외부 배출의 경우 틈 간격은 응축량에 매우 큰 영향을 미쳤는데, 틈 간격이 줄어듦에 따라 응축량이 매우 증가하는 결과를 얻었다.

Keywords

References

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