A numerical investigation of the sCO2 recompression cycle off-design behaviour, coupled to a sodium cooled fast reactor, for seasonal variation in the heat sink temperature

Mapping of the thermodynamic performance of the supercritical CO2 cycle and optimisation for a small modular reactor and a sodium-cooled fast reactor

“…CYCLOP has been validated on Rankine steam cycles coupled to French Pressurized Water Reactors (such as CRUAS) and the French SFR Superphenix. It has also been extensively benchmarked in the frame of R&D programs, from the helium Brayton cycle applied to a Gas-cooled Fast Reactor concept [25] to the sc-CO 2 cycle for an SFR [16]. In this code, the CO 2 properties are determined from the Helmholtz free energy equation of state [27].…”

“…The real deviation would be defined through an offdesign study of the cycle with a thermohydraulic system code as performed in Ref. [16] with the Plant Dynamics Code from Argonne National Laboratory [29]. In support to condensing mode, which has been reported as the most promising cycle design, further studies are planned to consider the risk of possible cavitation of the main compressor as well as the off-design behaviour of this component through the liquid and supercritical regions.…”

A numerical model for the CO2–sodium chemical interactions in Sodium Fast nuclear Reactors

“…The pre-exponential factor and activation energy of an Arrhenius law were determined by Eoh et al, but only for the specific case of a CO 2 -Na flat free surface contact, without continuous mixing. In the case of leakage inside a CO 2 -Na heat exchanger, an underexpanded CO 2 -into-liquidsodium jet would form, due to the extremely high CO 2 -to-Na operative pressure ratio (more than 200 bar in the CO 2 side and nearly atmospheric pressure in the sodium side (Floyd et al, 2013)): the contact mechanism between sodium and CO 2 is, therefore, significantly different from a flat surface contact. The global kinetics parameters are fundamental in order to develop a numerical model of the leakage, which, in turn, would be useful to understand the production rate, the space and time distribution of the solid products as well as the temperature variation inside a Na-CO 2 heat exchanger and on the tube surfaces, following a leakage scenario.…”

“…In SFRs, sCO 2 Brayton cycles represent an interesting alternative to water Rankine cycles (Alpy et al, 2011;Floyd et al, 2013), since they eliminate the wastage accidental scenario caused by the sodium water reaction (SWR) (Eoh et al, 2010) and feature high thermodynamic plant efficiency (up to 42%, Floyd et al, 2013). Nevertheless, CO 2 reacts exothermically with sodium, forming solid reaction products.…”

Thermoeconomic Analysis and Optimization of a New Combined Supercritical Carbon Dioxide Recompression Brayton/Kalina Cycle

“…Thermodynamic analyses were performed by Kim et al for a transcritical CO 2 cycle utilizing both low and high temperature heat sources [15]. Floyd et al described the off-design response of a SCRBC coupled with a sodium fast reactor as the heat sink temperature changes [16]. Singh et al proposed an extremum-seeking controller to enhance the performance of a direct heated S-CO 2 closed loop Brayton cycle for a fluctuating solar input energy and ambient temperature [17].…”