Condensing heat transfer within horizontal tubes

[摘要] The purpose of this investigation was to study the effect of vapor velocity, temperature difference and fluid properties upon the heat transfer coefficient of a vapor condensing within a horizontal tube. Condensing heat transfer coefficients for propane were measured over a wide range of conditions.The data would not correlate using the existing equations for condensation. A new mechanism was postulated of a laminar condensate film, forming an annulus next to the tube wall, surrounding a turbulent vapor core. On this basis, the following equation was derived: hDkPr -13=B DGamL rLrV 12 nThe data correlate to approximately 20% using this equation. The value of 'n' was 0.2 at low Reynolds numbers and approached a constant value of 0.8 at a Reynolds number of 105.The effect of the liquid loading and the temperature difference across the condensing film on the heat transfer coefficient was negligible over the range of the investigation.

[发布机构] Rice University

[效力级别] engineering