Heat transfer during condensation inside a horizontal tube

[摘要] Heat transfer data were taken for methanol and Freon-12 condensing inside a horizontal tube over considerable ranges of pressure, temperature driving force, liquid loading, and vapor velocity.A single mechanism for heat transfer could not explain the behavior of this and other data over the entire range of the variables. For condensation in a horizontal tube, three primary regions of flow are postulated: (1) semi-stratified flow (annular condensation and run-down superimposed on stratified flow), (2) laminar annular flow, and (3) turbulent annular flow.A semi-theoretical equation,NuPr-1/3=0.388 M1/6DGvm r/rv 1/21/4is developed and shown to be applicable to both semi-stratified and laminar annular flow. Other equations must be used for turbulent annular flow.

[发布机构] Rice University

[效力级别] engineering