Simulation, analysis and control of a self-propelling heat removal system using supercritical CO2 under varying boundary conditions

Start-up, operation and thermal-hydraulic analysis of a self-propelling supercritical CO2 heat removal system coupled to a pressurized water reactor

“…The design, layout, and control of the CO 2 cycle were already presented in [17,22]. Therefore, only the most important points are summarized here.…”

“…Bestion [6] compares different thermal-hydraulic system codes regarding their models, capabilities, and limitations. A short introduction to ATHLET is provided in [1,17].…”

“…The turbomachinery models are performance map based and use a real gas similarity approach [20] to account for changes in the inlet conditions. They also provided a design approach for the sCO 2 -HeRo system and analyzed the sCO 2 cycle with varying decay heat [21] and at different ambient temperatures [17,22]. The cycle was successfully operated in part-load by adapting the rotational speed of the turbomachinery, keeping the compressor inlet temperature constant and without the need for inventory control.…”

“…The cycle was successfully operated in part-load by adapting the rotational speed of the turbomachinery, keeping the compressor inlet temperature constant and without the need for inventory control. In [17,22], the modeling and design were improved, including new sCO 2 turbomachinery performance maps with a higher surge margin, and the start-up from an operational readiness state (ORS) was considered. Using Modelica coupled with ATHLET, Frýbort et al [23] presented a first analysis of the challenging push-start from shutdown conditions and an alternative control strategy for low ambient temperatures, a combination of inventory control and UHS bypassing.…”

“…start at low ambient temperatures or determination of an appropriate heating procedure. The sCO 2 -HeRo system was integrated and simulated coupled to an EPR, VVER 1000, and Konvoi PWR with CATHARE, ATHLET/Modelica, and ATHLET, respectively [17,24]. In all power plants, the same modular sCO 2 -HeRo system with a heat removal capacity of 10 MW per sCO 2 cycle was installed, and successfully coupled simulations with a different number of systems were performed.…”