Experimental and computational study of thermalhydraulic processes in VVER-1000 core melt confining heat exchange device

Full text of publication follows: The paper presents the computational and experimental results on study of heat-and-mass transfer processes using a large-scale model of VVER-1000 core melt confining heat exchanger. The description of the experimental device model, measuring base and the test procedure is given. The central angle of the model is 100. The shell of the model is made of plate steel with a thickness of 10 mm. The model is 5370 mm in height, 800 mm in width; its horizontal dimension is 3175 mm. The heated surface is made of stainless steel 1X18H10T with a thickness of 1 mm. The heat flow density is 0.6 MW/m2. The model is heated by direct current (1200 kW). In the upper part of the model there are peepholes. The steam quality was measured by the conductance-measuring method. The local quality was determined by the time the steam inclusions passed through the sensing element of electric resistance probe. The main experimental results obtained are the following: the stable level of liquid, the maximum permissible heat flux. The computational study of boiling has been performed using the TURBO-FLOW computer code. The description of the computational model and the results as obtained are given. The objective of the computational investigations is to compare the calculations with the experiment, obtain the permissible moisture content near the heated wall, and develop heat removal improving at water level decreasing. The comparison of the experimental results with the calculations has been performed. The boundaries of the device serviceability and the ways of design improving have been determined. (authors)