Transient model of carbon dioxide desublimation in plate-fin heat exchanger of cryogenic reverse Brayton refrigerator

Desublimation-based cryogenic carbon capture has garnered significant attention as a strategy to mitigate global warming. Cryogenic reverse Brayton refrigerator (CRBR) has shown promising application prospects to be applied as the cryogenic source for CO₂ capture, while the constantly changing boundary conditions and interdependency matching between regenerator and turbo-expander complicate the accurate prediction of CO₂ desublimation in CRBR. In this paper, a transient model is developed to evaluate the CO₂ desublimation performance in CRBR. The proposed model is verified by experimental data and shows good agreement. Thereafter, the characteristics of CO₂ desublimation in CRBR are quantitatively investigated under two capture strategies. A comparative study shows that post-turboexpander capture can achieve a higher capture rate at the expense of reduced capture quantity. Additionally, the proposed model offers a deeper understanding of CO₂ desublimation characteristics within the plate-fin heat exchanger, facilitating the future design and optimization of cryogenic systems in various capture processes.