Fusion DEMO sCO 2 Layout Design with Battery Farm

Abstract

Nuclear fusion is a promising low-carbon and low-emission source of energy. The first fusion power plant is the European Union's demonstration fusion power plant DEMO. One of the key attributes that influences the whole DEMO design is the power plant pulse operation. Due to the power fluctuations and instability of the power source, there may be a significant impact on the power grid, turbine, etc. Therefore, a power conversion system based on a supercritical CO2  capable of operating in two nominal power levels is proposed. The system operates in nominal parameters during the entire power cycle without the need for thermal power pulses balancing. Unlike other designs, instead of connecting the energy storage system directly to the primary circuit, this article proposes a layout with energy storage behind the generator. Power pulses are balanced using a battery farm, compensating the fluctuations in the gross power and power plant self-consumption. Power conversion system is based on a sCO2 Brayton simple cycle with regeneration and includes technology for nominal operation at two levels of thermal power. Optimization of the proposed layout shows lower thermodynamic net efficiency of 24 % in comparison with other applications such as nuclear or coal power plants.