EN Methodology for recalculating the thermal-hydraulic characteristics of straight-through cylindrical steam generators operating on freon coolant, from boundary conditions of the second kind to third kind

The methodology presented in the article allows calculating the thermal-hydraulic characteristics of direct-flow cylindrical steam generators operating on a freon coolant for boundary conditions of the third kind. The purpose of this article is a calculation to determine the length of the channel required for complete evaporation of the coolant, the power expended on pumping the evaporating coolant and the amount of heat required for evaporation of the coolant. In addition, of significant interest is the search for design parameters of steam generators with heat exchange intensifiers, with which it is possible to obtain an energy gain compared to smooth-walled steam generators. This gain can be obtained only under boundary conditions of the first or third kind. In the case of boundary conditions of the second kind, according to the law of conservation of energy, with the same heat flows on the surface, for a channel with a heat exchange intensifier and for a smooth-walled channel, the same length of these channels is required for the evaporation of the same amount of liquid. Considering that the hydraulic resistance of channels with a heat intensifier is higher than the hydraulic resistance of smooth-walled channels, it is impossible to obtain an energy gain in this case. It should be noted that since the analytical dependencies available in the literature for the thermal calculation of the evaporation sections of direct-flow steam generators were mainly obtained for the boundary conditions of the second kind, it is necessary to create a method for recalculating the thermal-hydraulic characteristics of direct-flow steam generators from the boundary conditions of the second kind, in particular, for the boundary conditions of the third kind. This is ultimately necessary for conducting a comparative analysis of direct-flow freon steam generators with heat exchange intensifiers and smooth-walled freon direct-flow steam generators