Start-Up and Transient Operation Modelling of a Demo sCO2 Recuperated Cycle

Abstract The supercritical carbon dioxide (sCO2) cycles are a promising technology for the future of energy systems and power production systems. These cycles are currently widely studied for different applications, as they can easily adapt to various configurations. Generally, they can either achieve performance similar to mature technologies such as steam cycles or ORC, or reach better efficiencies when complex configurations (e.g. re-compressed cycle) are considered coupled with high temperatures and pressures. Despite the competition with more traditional technologies, the sCO2 cycles can still gain advantage of reduced footprint of the plant, especially for turbomachinery, simpler balance of plant and auxiliaries, and cost-effective equipment. Another important aspect is the flexibility that the sCO2 plants could have and that could be highly advantageous, especially in markets or applications that require a simple management or a quick variation of the power produced. However, flexibility and transient operation still need to be demonstrated in practice. In order to study these aspects, the EU-funded project SOLARSCO2OL aims at the construction of the first European MW-scale sCO2 plant coupled with a Concentrated Solar Plant (CSP). This paper, developed in the framework of the SOLARSCO2OL project, follows previous works in which a dynamic performance model of the demonstration plant was developed in the TRANSEO simulation tool. This work presents the latest update of such a model and its utilization in the testing of control strategies developed for the demo plant, focusing particularly on start-up and transient operations.