Process simulation and techno-economic assessment of a flexible refrigeration system integrated with CO2 hydrate-based cold storage

This paper presents a process simulation and techno-economic assessment of a CO₂ Hydrate Refrigeration Storage System (CHRS-CS), a novel flexible solution that integrates CO₂-hydrate-based cold storage with conventional CO 2 refrigeration cycles. The CHRS-CS is charged and forms CO 2 hydrate during low-ambient, off-peak periods by directly injecting condensed CO₂ into a pressurised water reactor and discharged through hydrate dissociation during high-ambient peak hours. The dissociated cold energy provides supplemental subcooling, mitigating operating pressures and trans-critical operation penalties as well as improving system techno-economics. Thermodynamic results indicate that, relative to the commercial Panasonic baseline, the CHRS-CS reduces peak electricity consumption by ~9%–19% depending on the evaporating temperature, while increasing the annual average coefficient of performance (COP) by ~10.6%–25.2%. The techno-economic assessment based on a Madrid case further shows that the CHRS-CS achieves ~10–16% lower capital expenditure and total installed cost, alongside annual operating expenditure savings of ~12%–26%. Correspondingly, the levelized cost of cooling is reduced by approximately ~12%–24% to ~68–98 €/MWh. These findings demonstrate that CHRS-CS can remarkably improve techno-economic performance of conventional CO₂ refrigeration systems and reduce peak electricity demand through cold-storage-based load shifting, offering a new promising refrigeration solution especially for low-refrigeration applications.