LHP Architecture and Advanced Wicks for Freeze Tolerance

This proposal describes a freeze-tolerant water loop heat pipe (LHP) as the solution to the spacecraft high temperature electronics thermal removal and transportation problem when operating between 100°C-200°C. Water LHPs -- owing to their many favorable system attributes that include high conductance, passive operation, operating temperature applicability, compactness, heat load/transport length scalability, integration flexibility, low mass, no-moving-part reliability, low cost, benign nature, and dual-use potential -- are uniquely suited to meeting the high temperature electronics thermal management system technology objectives. Water is a desirable choice of working fluid not only because of its excellent thermal properties but it is a fluid that is accepted from a safety perspective which would allow it to be used in a wide variety of applications, including commercial electronics. Unfortunately, despite the promise of water LHPs, their freeze-tolerance remains a critical problem that must be solved to ensure long-life operation in warm/cold environments. The technology proposed herein will result in a freeze-tolerant water loop heat pipe. BENEFIT: In addition to the solicitation topic of cooling for spacecraft high temperature electronics, additional post applications for the freeze-tolerant water LHP technology include, but are not limited to, the following ground/space applications: (1) commercial PC cooling (CPU, video cards, etc); (2) industrial electronics (3) Hybrid electric vehicle (HEV) component cooling; (4) commercial aircraft electronics cooling; (5) avionics cooling in military aircraft; (6) military hybrid vehicle cooling; and (7) others.