Proposal of optimized power cycles for the DEMO power plant (EUROfusion)

Highlights: • Proposal of two PCS different from the solution considered for the DEMO 2017. • Configurations aimed to maintain constant the operation at the pulse and dwell. • Secondary energy storage system for the cooling of divertor and vacuum vessel. • Configurations are simulated both at pulse and dwell operation modes. • They allow a completely steady operation of the power conversion system. -- Abstract: The objective of this paper is the proposal of two configurations of Rankine cycles different from the standard solution considered for the DEMO 2017 design. The configurations are aimed to maintain as constant as possible the operation at the pulse and dwell modes with minimal fluctuations in the turbine and heat exchangers parameters, in order to maximize the reliability of these components. Each configuration, as well as the reference one, have been simulated both at pulse and dwell operation modes. Compared to the reference design, the proposed configurations are much steadier and mass flow rates in the steam generator and preheaters are constant. In summary, it is possible to ensure a completely steady operation of the whole steam cycle, including all the heat exchangers, without differences between the pulse and dwell modes using two secondary storage tanks additional to the two original molten salt ones.