Experimental Investigation and Modelling of Film Evaporation in the Presence of Countercurrent Air Flow

Abstract

This paper describes the results of experimental tests carried out to study falling film evaporation on a heated flat plate with countercurrent air flow. The considered data are related to inlet film and plate temperatures of 70, 80 and 90°C. The considered range of parameters was chosen with reference to innovative nuclear reactors equipped with passive containment decay heat removal systems. The first part of the paper summarises the characteristics of the experimental facility and of the obtained experimental data. The methodology developed for modelling film evaporation is then presented. The countercurrent steady-state flow is simulated by non-equilibrium two-fluid balance equations, which are numerically integrated making use of appropriate constitutive equations. The calculated results are then compared with experimental data, drawing conclusions about the applicability of the analogy between heat and mass transfer