Steam cycle optimization study of thermal energy storage for nuclear power plants responding to renewable energy

Abstract

To address global warming issues, the share of renewable energy is increasing due to low-carbon energy policy around the world. However, as the proportion of renewable energy increases, the concerns about stable power supply are raised. In most cases, renewable energy sources are intermittent. This intermittent supply of renewable energy requires load variation from other power sources to meet power demand. In this study, thermal energy storage (TES) integrated nuclear power plants (NPPs) is proposed as a solution to this problem. A generic steam cycle of a nuclear power plant is developed by referring to the pressurized reactor model and the cycle conditions are established for integrating a thermal energy storage system. Turbines and heat exchangers, which are components of the steam cycle, vary in performance depending on the operating conditions. While the branch flow to the thermal energy storage system is increased under specific cycle conditions, steady state condition at each off-design point is analyzed. Through the optimization result, the change of cycle output with respect to the branch flow and corresponding thermal energy delivered to the thermal energy storage system are evaluated.