Dynamic Modeling and Transient Analysis of a Recompression Supercritical CO2 Brayton Cycle

As an ideal renewable power generation technology, concentrated solar power is currently too expensive to be competitive. Supercritical CO2 power generation cycle is a promising power generation technology with high potential to reach high thermal efficiency and high flexibility, which could be combined with concentrated solar power to reduce its cost of electricity. In this work, a recompression cycle with intercooling and preheating is selected for the application of supercritical CO2 cycle in concentrated solar power. A dynamic physical model of selected cycle is built in Modelica language implemented in Dymola. Part load transient scenarios are defined with technical constraints, such as minimum main compressor inlet temperature and minimum molten salt outlet temperature. With these key scenarios defined and constraints integrated into the model, sensitivity analyses are carried out to understand system dynamics. Global operation and control strategies for system protection, regulation and performance optimization are proposed and designed within MAILAB&SIMULINK to satisfy the pre-defined performance criteria. Finally, part load scenario simulations are done with inventory control, bypass control and their combination to justify their feasibility.