Modeling and Optimization of a Cryogenic CO2 Deposition System Using Computational CL24_4476.pdf

Modeling and
Optimization of a
Cryogenic CO2
Deposition System
Using Computational Fluid Dynamics and StarCD

1. Modeling and
Optimization of a
Cryogenic CO2
Deposition System
Using Computational
Fluid Dynamics
382I –Cryogenic Systems Engineering Group
Presented by Asa O’Neal
8/21/2024
Reviewed and determined not to contain CUI.

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Background
12.4: Phas e Diagrams - Chemis tr y LibreTexts Sublimation Definition (Phase Trans ition in Chemistry ) (thoughtco.com)
CO2 Deposition = CDep
Gaseous CO2 Solid CO2
Deposition
Sub lima tion
Reviewed and determined not to contain CUI.

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System
Chen et al.
190 K
0.015 kg/s
(~ 26 SCFM)
2600 ppm
Cold Surfaces
Deposit CO2
Low CO2
Concentration
-Cryogenic CO2 Scrubber for Human Spaceflight.
-Two scrubbers alternate between depositing and
sublimating CO2 for continuous removal.
-Flow and icing are dependent on cold surface
geometry.
Heat Pipe
(~120-125 K)
High CO2
Concentration
Target:
<480 ppm
Reviewed and determined not to contain CUI.

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Context and Meaning
•Compact, reliable, reduced
maintenance
•Potential successor to the
Carbon Dioxide Removal
Assembly (CDRA).
•Replaces consumable
adsorption systems.
•Ideal for long-duration
missions.
•CO2 is sublimated for
downstream processing: ISRU
•Can also remove trace
contaminants from cabin air.
NASA astronauts Sc ott Kelly (left) and Terry Virts (right) work on a Carbon Dioxide Remo val
Assemb ly (C DRA) inside the station's Jap an ese Experiment Module. Credits: N ASA
NASA astronauts Shane Kimbrough and Mark Vande Hei install the
Four Bed CO 2 Sc ru bber on th e s pace station.Credits: N ASA
Reviewed and determined not to contain CUI.

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Scope
Temperature
Concentration
Channel Clogging
•Use STAR-CCM+ CFD to maximize CO2 capture and mitigate channel clogging.
•Evaluate design without expensive build/test cycles.
8/21/2024
Flow
Direction
Flow Direction
Reviewed and determined not to contain CUI.

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Overview
8/21/2024
24
Surfaces
32
Surfaces
40
Surfaces
•Involute geometry provides several advantages (surface area, heat pipe integration etc.).
•CFD enables flow/icing visualization and performance evaluation.
•Inexpensive design exploration.
CO2 Concentration
Ice Thickness
Reviewed and determined not to contain CUI.

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Findings
8/21/2024
Flow Direction
Gap
Reviewed and determined not to contain CUI.

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Improving Design
8/21/2024
•Fin shortened because CO2 preferentially deposited on upstream surface for efficient use of volume/surfaces.
•24 Surface variant explored since estimated time to clog was the longest.
•Drafted design explored with hopes to increase time to clog.
Reviewed and determined not to contain CUI.

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Applying Results
8/21/2024
•More efficient to use shorter fins.
•Fins shortened even further to ¼” since icing was still disproportionate.
•Undrafted version used for simplicity and array of 16 staggered fins was constructed.
•Did not meet target objective but results extrapolated to size final array.
16-Fin Array
Reviewed and determined not to contain CUI.

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Final Design
8/21/2024
•By extrapolating results and assuming 7.7% capture per fin, it was predicted that a 24-fin array would reach 380 ppm.
•Simulation results agree with prediction
•Important because simulating a few fins can allow for extrapolation to size an array.
•Meets target CO2 capture objectives (4.16 kg/day for a 4-person crew).
24-Fin Array
Reviewed and determined not to contain CUI.

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Conclusions
8/21/2024
•Better to use fins that are short in the
direction of flow.
•Number of involute surfaces must be
balanced against time to clog channel.
•Simulating a few fins to find capture
efficiency can be extended to size an array.
•Recommended to start with an array of 24
staggered fins, each with 24 surfaces, ¼”
depth and separated by 3mm.
Units in mm
Reviewed and determined not to contain CUI.

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Limitations & Future Work
8/21/2024
Limitations:
•Heat loss through tube walls neglected.
•Heat pipe treated as constant
temperature.
•Only 120s simulated due to model
limitations.
•Inlet/Outlet flow modeled as uniform
across entire diameter.
Future Work:
•Build and test suggested array design
with 45-minute cycle time.
•Incorporate into regenerative design to
reduce power requirements.
Other Work:
•Create STAR-CCM+ training materials.
•Further develop CAD model of
regenerative design.
•Presented technology to astronauts at
the Astronaut Scholar Technical
Conference.
Reviewed and determined not to contain CUI.

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Acknowledgements and Sources
Acknowledgements
-Diego Fonseca Flores, Weibo Chen, Scott Roberts, Grace Belancik, Michael Schuh.
-382I – Cryogenic Systems Engineering Group
-Kentucky Space Grant Consortium
-The High-Performance Computing resources used in this investigation were provided by funding from
the JPL Information and Technology Solutions Directorate.
Sources
-G. Belancik, M. Schuh, D. Jan and P. Jagtap, "Evaluating Capabilities of the Carbon Dioxide Deposition
System," in International Conference on Environmental Systems, 2020.
-G. Belancik, M. Schuh, D. Jan and P. Jagtap, "Modeling Performance of the Full Scale CO2 Deposition
System," in International Conference on Environmental Systems, Virtual, 2021.
-W. Chen, L. D. Fonseca Flores and S. N. Roberts, "A Cryogenic CO2 Scrubber with an Integrated
Switchable Heat Pipe," in International Conference on Environmental System, Calgary, 2023.
Reviewed and determined not to contain CUI.

14. jpl.nasa.gov
8/21/2024 Reviewed and determined not to contain CUI. 14