TY  - EJOU
AU  - Zhu, Hao 
AU  - Chen, Xi 
AU  - Qu, Pengcheng 
AU  - Zhu, Yifan 
AU  - Wang, Haoyi 
AU  - Qi, Yingxia 

TI  - Numerical Investigation of CO<sub>2</sub> Contaminant Transport and Deposition in an In-Line Pulse Tube Cryocooler
T2  - Frontiers in Heat and Mass Transfer

PY  - 2026
VL  - 24
IS  - 1
SN  - 2151-8629

AB  - Pulse tube cryocoolers are widely employed in cryogenic systems, where gas contamination has become a critical factor limiting both performance and service life. To further investigate the condensation behavior of contaminants, this study develops a two-dimensional axisymmetric model of a linear-type cryocooler to simulate the transport and deposition processes of trace CO<sub>2</sub>, evaluating the impact of contamination on system pressure drop under various operating conditions. Results indicate that CO<sub>2</sub> diffusion is primarily driven by concentration gradients. The CO<sub>2</sub> deposition rate increases markedly at low temperatures and high concentrations, with over 90% of deposition occurring in the cold-end heat exchanger. Under different concentration distributions, dry ice predominantly accumulates in the cold-end heat exchanger; however, notable differences emerge in the pulse tube. In the uniform distribution case, CO<sub>2</sub> tends to deposit along the inner wall of the pulse tube, whereas in the gradual release scenario, deposition mainly occurs on the cold-end flow straightening mesh screen. Dry ice deposition significantly increases the pressure drop across the system and decreases the pressure wave amplitude, resulting in a degradation of cooling capacity. This study lays a foundation for further investigation into the thermal properties of contaminant layers and provides theoretical guidance for optimizing cold-end components to improve contamination resilience.
KW  - Pulse tube cryocoolers; carbon dioxide; dry ice deposition; CFD

DO  - 10.32604/fhmt.2026.076127