ISSN Online: 2377-424X
ISBN Print: 0-89116-559-2
International Heat Transfer Conference 8
THE CONDENSING CHARACTERISTICS OF NITROGEN IN PLAIN, BRAZED ALUMINIUM, PLATE-FIN HEAT-EXCHANGER PASSAGES
Аннотация
Condensing heat transfer coefficients and pressure gradients have been obtained with nitrogen in vertical downflow in a plain, plate-fin test section for a range of low mass fluxes and pressures. In the paper, the measured coefficients are compared with predictions from the Nusselt and Dukler and other methods, none of which is satisfactory. A new model of condensing with a falling film is advanced: it takes into account turbulence and the shear stress variation across the film. By using a double velocity profile and the measured pressure gradients, the new method gives better predictions for these small rectangular finned channels.