Journal of the Korean Institute of Gas (한국가스학회지)

The Korean Institute of GAS (한국가스학회)
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Numerical Study on Steam-Methane Reaction Process in a Single Tube Considering Porous Catalyst

다공성 촉매를 고려한 단일튜브 내의 수증기-메탄 개질에 관한 수치해석 연구

  • Moon, Joo Hyun (Dept. of Mechanical Engineering, Chung-Ang University) ;
  • Lee, Seong Hyuk (Dept. of Mechanical Engineering, Chung-Ang University) ;
  • Yoon, Kee Bong (Dept. of Mechanical Engineering, Chung-Ang University) ;
  • Kim, Ji Yoon (ESRI(Energy.Safety Research Institute) of Chung-Ang University)
  • 문주현 (중앙대학교 기계공학부) ;
  • 이성혁 (중앙대학교 기계공학부) ;
  • 윤기봉 (중앙대학교 기계공학부) ;
  • 김지윤 (중앙대학교 차세대 에너지안전연구소)
  • Received : 2014.07.28
  • Accepted : 2014.08.26
  • Published : 2014.08.31
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Abstract

The present study investigated numerically heat and mass transfer characteristics of a fixed bed reactor by using a computational fluid dynamics (CFD) code of Fluent (ver. 13.0). The temperature and species fraction were estimated for different porosities. For modeling of the catalyst in a fixed bed tube, catalysts were regarded as the porous material, and the empirical correlation of pressure drop based on the modified Eugun equation was used for simulation. In addition, the averaged porosities were taken as 0.545, 0.409, and 0.443 and compared with non-porous state. The predicted results showed that the temperature at the tube wall became higher than that estimated along the center line of tube, leading to higher hydrogen generation by the endothermic reaction and heat transfer. As the mean porosity increases, the hydrogen yield and the outlet temperature decreased because of the pressure drop inside the reformer tube.

본 연구에서는 촉매가 들어있는 고정층 반응로의 단일 개질관에 대하여 전산 유체 해석(Fluent ver. 13.0)을 수행하여 열/유동 특성을 파악하고, 주입 가스에 따른 추출 가스의 종류를 다공성에 따라 예측하였다. 촉매 형상을 모델링하기 위하여, 개질관 내부에 있는 촉매를 모두 다공성 물질이라고 가정하고, 수정된 Eugun 식을 해석에 적용하였다. 유체의 공극률을 기준으로 0.545, 0.409, 그리고 0.403로 설정하고, 결과를 비 다공성인 경우와 비교하였다. 수치해석 결과, 개질관 벽면의 온도는 흡열반응과 주변 열전달로 인하여 개질관의 온도보다 높게 나타나며, 수소 생성량도 다소 증가했다. 촉매의 공극률이 증가 하게 될 경우, 압력 강하로 인하여 관 중심부 온도 및 수소 생성량이 현저하게 감소하는 경향을 보였다.

Keywords

References

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