Performance comparison of PWR/EPR and steam generator with and without economizer

The article presents a model of a steam generator based on mass and energy balance equations, heat transfer coefficients, criterion relations and Peclet’s law. The presented model was applied to a steam generator without and with an economizer for a PWR/EPR nuclear power plant. Based on the calculations, the steam pressure at the outlet of the steam generator without the economizer is 74.17 bar, and for the model with the economizer it is 77.2 bar. The pressure difference for these two variants, based on the calculations, was therefore 3 bar. Higher steam pressure at the outlet of the steam generator translates into a greater enthalpy drop in the turbine and greater power generated by the steam turbine and the efficiency of the entire nuclear power plant. Based on the economic calculations carried out for 60 years of operation of a nuclear power plant with four steam generators, the profit from the use of the economizer amounted to about PLN 0.6 billion.