Heat transfer in a supercritical region at low pressure and small flow rates

The results of heat transfer study are presented for a dispersed two-phase flow under the film boiling conditions at P=0.05-0.3 MPa pressures, small flow rates rho#betta#=16.9-168.9 kg/m2xs and dryness factor at the channel inlet x0=0.7-1.03. These conditions are characteristic of emergency and postemergency situations of nuclear reactor- and steam generator operation. Experimental installation and methods of studying are described, an analysis of multiple experimental data for a superheated steam has been carried out, and the formula has been choosen that applies best of all to the test data of the present study. Experiments with a humid steam have shown that the wall temperature falls monotonously over all cross sections along a heated plate with a condensed moisture increase in the effuse, i.e the heat transfer factor for a two-phase flow increases as a whole. An analysis of physical processes, leading to the heat transfer increase under the film regime, is given. Experimental data for heat transfer in a dispersed flow have been approximated by formular wich describes the experimental points to the 15% accuracy