低压两相流模型过冷沸腾(完成).pdf

International Journal of Heat and Mass Transfer 49 (2006) 377–386 /locate/ijhmt Two-fluid modeling for low-pressure subcooled flow boiling J.L. Xu a, T.N. Wong b,*, X.Y. Huang b a Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, No. 81 Xianlie Zhong Rd., Guangzhou 510070, PR China b School of Mechanical and Production Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798, Singapore Received 9 November 2003; received in revised form 30 September 2004 Available online 30 September 2005 Abstract In the advanced electronic packaging, low-pressure subcooled flow boiling has been applied in design of compact heat exchangers for the effective electronic cooling. Through literature survey it is noted that little studies were carried out on the low-pressure and low-flow velocity subcooled flow boiling. In this paper a one-dimensional, non-equilibrium two-fluid model is proposed. The model has been validated with existing data in literature for both vertical up-flow and down-flow configurations. The simulated results show that under low-flow velocity the single phase heat transfer frac- tion is insignificant in vapor generation rate. The predicted results indicate that buoyancy force plays an important role on the void fraction evolvement, especially under low-flow velocity in vertical down-flow configuration. 2005 Elsevier Ltd. All rights reserved. Keywords: Subcooled flow boiling; Void fraction; Two-fluid; Vapor generation 1. Introduction the temperature of the bulk liquid and the wall increas