Dynamic Modeling of 5 MWe Supercritical CO2 Recompression Brayton Cycle

Supercritical CO2 (SCO2) Brayton cycle is a promising alternative power generation technology as a substitute for steam Rankin cycle, mainly due to its high efficiency and compact turbo-machinery. Concentrated Solar Power (CSP) plant could be a first industrial application of SCO2 cycle for the next generation tower technology. In order to better understand cycle dynamics during operation and to design dedicated control strategies, dynamic modeling and simulation is necessary. In this work, a preliminary SCO2 Brayton recompression cycle model is developed, with all the key cycle components modeled in different details. Based on this model, some typical transient scenarios such as cycle maximum temperature variation, cycle minimum temperature variation and inventory injection & extraction are simulated and the resulted are presented and analyzed. The simulations show that highly non-linear behavior of thermodynamic properties and efficiency, especially near the low temperature and high temperature recuperator.