Korean Journal of Air-Conditioning and Refrigeration Engineering (설비공학논문집)

The Society of Air-Conditioning and Refrigerating Engineers of Korea (대한설비공학회)
권호 표지

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
Download PDF
⟨ Previous Next ⟩

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.

Keywords

References

  1. Int. J. Refrigeration v.19 no.5 Review Paper: Heat-transfer enhancement by additives Ziegler F.;Grossman G.
  2. Proceedings of 1st KSME-JSME Thermal and fluid Eng. Conference v.1 Marangoni effect in the process of steam absorption into the falling film of the aqueous solution of LiBr Kashiwagi T.;Watanabe H.;Omata K.;Rie D.H.
  3. J. Chemical Engineering of Japan v.24 no.2 Marangoni convection during steam absorption into aqueous LiBr solution with surfactants Hozawa M.;Inoue M.;Sato J.;Tsukada T.
  4. Int. J. Refrigeration v.16 no.5 Effect of surfactant on falling film absorption Hihara E.;Saito T.
  5. Proceedings of the ASME v.39 Theory of heat/mass Transfer additives in absorption chillers Kulankara S.;Verma S.;Herold K.E.
  6. Int. J. Refrigeration v.19 no.5 Experimental in vestigation of heat transfer in a horizontal tube falling film absorber with aqueous solutions of LiBr with and without surfactants Hoffmann L.;Greiter I.;Wagner A.Weiss V.;Alefeld G.
  7. Proceedings of 34th National Heat Transfer Conference Experimental investigation of absorber performance with and without 2-ethyl-hexanol in H2O-LiBr absorption cycle Kyung I.S.;Herold K.E.
  8. Transactions of the KSME v.24 no.8 An experimental study on flow and heat/mass transfer characteristics of LiBr-H₂O solution flowing over a cooled horizontal tube Seol S.S.;Lee S.Y.
  9. The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea v.22 no.1 The principle and technic of application and operation of absorption chiller-heater Kim K.J.
  10. J. Chemical Engineering Data v.39 no.1 Surface tension of aqueous litium bromide+2-ethyl-1-hexanol Kim K.J.;Berman N.S.;Wood B.D.