HEAT TRANSFER ANALYSES OF LIQUID-HEATED BOILING FLUIDS WITH ATTENTION TO TRANSITION BOILING (FLOW, NUMERICAL).

摘要

Four major methods of analysis were developed for the turbulent flow of a liquid metal in an annulus under a thermally developing condition with arbitrary axial wall temperature distribution. The methods were applied to measurements made in two large scale test facilities, at Argonne National Laboratory and Westinghouse Electric Corp., where water boiling inside of a tube was the forcing function for heat transfer in a surrounding sodium annulus. The primary application of the methods is in the area of reduction of experimental data from liquid-metal heated steam generator tests. The tests considered covered a range of water parameters of 400-2500 kg/m('2)s mass flux and 6.9-15.6 MPa pressure.;The region of highest thermal gradients was investigated in an ancillary study of transition boiling heat transfer under sodium-heated conditions. Models were developed for the inclusion of transition boiling heat transfer in the overall thermal analysis of liquid-heated, boiling water heat exchangers. Two empirical relations, developed from extensive available data, were key features in the application of these models.;Results from the four methods (and modifications of them) were compared on a quantitative basis for calculated parameters of heat flux, wall temperature, water temperature, quality and heat transfer coefficient. Since the methods differed significantly in complexity, the most inclusive method was used as a standard of comparison for the others. Particular attention was given to local regions of large thermal gradients where differences among the methods were most significant.