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.