• Energy Research

An original thermal-hydraulic method for optimizing the thermal resistance of thermal conductivity of fuel rod matrix upgrades has been developed to achieve the maximum burnup depth of nuclear fuel while ensuring safety conditions in operating and emergency modes of nuclear power plants. Based on the developed method, the boundaries of the optimization area for upgrades of the thermal resistance of the fuel rod matrix thermal conductivity are determined in accordance with the accepted optimization criteria and safety conditions. It is established that when optimizing upgrades to the thermal resistance of nuclear fuel, it is necessary to take into account both normal operating conditions and emergency conditions with impaired heat removal from the reactor core. It is established that the optimal values of thermal resistance of nuclear fuel thermal conductivity depend on the design and technical parameters of reactor installations, composition, and condition of nuclear fuel, accident management systems, and other factors.

The analysis of the world electric-energy balance revealed the advantage of steam turbine plants. An increase in their efficiency through the improvement of the initial parameters runs into difficulties associated with creation of new materials. The efficiency increase that results from the final pressure reduction requires an improvement of the circulating water supply system. The aim of this work is to determine the effect of the water-cooling tower on the electric power station profitability. This goal was reached by the creation of a mathematical model of the water-cooling tower and turbine plant with a condenser connected to each other. The calculations were made for two types of cooling tower fill packing: asbestos cement sheets and mesh elements made of polyethylene. Further, according to it, the vapor condensation temperature was determined. The latter affects the vapor discharge in the condenser, the capacity of the turbine plant and the temperature of the cooling water at the condenser output, i.e. at the cooling tower input. The novelty of this work consisted of consideration of the interaction between the cooling tower and turbine plant. Significance of the obtained results lies in the fact that, taking into account the reciprocal influence of the turbine plant and cooling tower, the efficiency of the fill packing replacement turns out to be major comparatively to the case without considering this influence. The replacement of the fill packings the half-a-year average temperature of condensation will become lower by 2.34 °С, electricity production increases by 41.72 GWh.