Additively Manufactured (AM) Condensing Heat Exchanger: Design & Sub-Scale Performance Testing



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2024 International Conference on Environmnetal Systems


The condensing heat exchanger (cHX) cools and removes humidity from the air on the International Space Station. In this program, an AM cHX is being developed using DMLS and Ti64 powder as a drop-in replacement. The innovative heat exchanger weave core has closely integrated hot-side and cold-side flow channels, to maximize thermal and flow performance and the air side flow channels are coated with an improved hydrophilic coating. The cHX also has an integrated water separator, termed the slurper, which separates the condensed water from the air stream. This additive cHX offers a 6x reduction in NRE cost primarily driven by a drastic reduction in number of parts (450+ for the legacy cHX compared to 13 for the AM cHX). The delivered AM cHX will be launched to the International Space Station and tested in a non-critical location. In support of this goal, various cHX performance sizing design and testing activities were conducted which will be covered in this presentation. (a) Firstly, a heat exchanger sizing optimization analysis was completed to select the specific core design. (b) Compatible header features were designed and integrated with the core for both uniform flow distribution and additive buildability. (c) Condensation water separator hole features were designed, fabricated, and coated to determine their ideal size and shape. (d) Slurper bars (water separator features) were then trialed, fabricated, and performance tested. (e) Flow coupons were fabricated and tested (f/j testing) for single-layer channel validation. (f) Core cubes were fabricated and tested for core validation. (g) A half-core cHX was fabricated for the purpose of further fabrication and performance risk reduction. The combination of these activities has led to the cHX design as it stands today, which will be fabricated for delivery to NASA in 2025.


Shane Haydt, RTX Technology Research Center, USA
Kimberly Saviers, RTX Technology Research Center, USA
Joseph Rampone, Collins Aerospace, USA
ICES104: Advances in Thermal Control Technology
The 53rd International Conference on Environmental Systems was held in Louisville, Kentucky, USA, on 21 July 2024 through 25 July 2024.


Condensing Heat Exchanger, Additive Manufacturing, DMLS Titanium 6Al-4V