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Indexed by:会议论文

Date of Publication:2006-07-17

Included Journals:EI、CPCI-S、Scopus

Volume:2006

Page Number:663-669

Key Words:condensation heat transfer; steam ethanol mixture vapor; surface-free-energy-difference

Abstract:The condensation heat transfer process of binary mixture of steam and ethanol vapor was studied experimentally with various ethanol concentrations and surface subcooling at atmospheric pressure. The experiments demonstrate that the condensation modes alter from filmwise, to transition and finally to dropwise with respect to the operation conditions. The marangoni effect was always used to interpret this phenomenon in the published literature. In this paper, the mechanism of condensation heat transfer with the liquid-solid-surface-free-energy-difference is used to further understand this process and the conversion of condensation modes. From this viewpoint, the condensation characteristics of binary mixture of steam and ethanol vapor can be explained reasonably with the corresponding condensation modes. Base on the data of the present paper and those reported in literature, the conversion criterion of the condensation modes is proposed. The condensation state is filmwise for the surface-free-energy-difference less than 14+/-1 mJ.m(-2) and dropwise for more than 21+/-1 mJ.m(2) and transition for between 14+/-1 mJ.m(2) and 21+/-1 mJ.m(-2).