[en] Experimental data on critical steam contents and temperature distributions over heated surface during steam-water mixture flow in annular channels with external and internal heating for pressures of 6.9-17.6 MPa and mass rates of 100-1000 kg/m²xs are given. An ingineering technique for calculating the heat exchange in the post-crisis zone of annular channels based on the nonequilibrium model of heat exchange in a disperse steam-droplet flow is suggested. Satisfactory agreement of wall temperature calculated values with experimental ones for the whole investigated range of regime parameters is obtained