A Study on Heat and Mass Transfer Characteristics of LiBr-$H_2$O Solution with a Sufactant Flowing over a Cooled Horizontal Tube

계면활성제 첨가시 수평 냉각관 외부를 흘러내리는 LiBr수용액의 열 및 물질전달 특성에 관한 연구

  • 김경희 (한국과학기술원 기계공학과) ;
  • 설신수 (한국과학기술원 기계공학과) ;
  • 이상용 (한국과학기술원 기계공학과)
  • Published : 2002.04.01

Abstract

Heat and mass transfer characteristics of a surfactant-added LiBr-$H_2O$ solution flowing over a single horizontal tube were examined experimentally. The parameters considered were surfactant (2-ethyl-1-hexanol) concentration, solution temperature at the top of the tube and absorber pressure. Even with an amount of the surfactant below the solubility limit, heat and mass transfer performances were enhanced tremendously. The Nusselt and Sherwood numbers increased by about 70% and 340%, respectively, when 10 ppm of the surfactant was added. However, an excess amount of the surfactant in the solution did not bring a further enhancement. The absorption performance deteriorated when the non-condensable gases were extracted from the system (by a vacuum pump) since the vaporized surfactant was also extracted during the process. Therefore, it is desirable to add a sufficient amount of the surfactant (more than 10 ppm) to maintain high performance of absorption.

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References

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