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 n The 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