Dynamic Phase Change Materials for Transient High Power Cooling
Abstract
Future Department of Defense systems that generate high power transient heat loads willrequire new technologies for high heat flux cooling and thermal storage. Phase change materials(PCMs) enable new concepts for thermal management, where the PCM provides localized coolingby storing energy through the latent heat of phase change. PCM-based thermal managementsystems may reduce system size and weight when compared to conventional cooling systems andcould potentially be applied for mobile applications such as all-electric orhybrid-electric ships,electric or hybrid-electric aircraft, as well as RF electronics and other DOD-relevant systems.The proposed research will study PCMs that undergo solid-to-liquid phase change uponpassing through a transition temperature. State of the art PCMthermal management solutionsbased on solid-to-liquid transitions can provide high cooling power for short periods, up to 10#s ofseconds. However, the development of a liquid later near the heat source leads to a decrease incooling power and renders these systems less effective for longer heating cycles. We propose todevelop thermal management systems based on dynamic phase change materials (dynPCM),which offer orders of magnitude improvements in energy density and power density whencompared to conventional PCM thermal management approaches. DynPCMs work by applyingpressure the PCM to maintain a thin layer of liquid between the solid PCM and the heat source,enabling high cooling power for thousands of seconds or longer.The goal of the proposed research is to develop engineering methods for integratingdynamic phase change materials with thermal management systems for high power transientcooling. The research will focus on multi-use systems that offer high power discharge from thesystem (melting) and high-power recharge (solidification), withthe goal of minimizing therecharge cycle time. We will investigate heat transfer during PCM discharge and recharge withthe goals ofmaximizing cooling power, minimizing recharge time, and developing engineeringdesign rules for integrating dynPCM with thermal management systems (TMS). The research willfirst focus on a flat plate configuration for dynPCM to develop a comprehensive engineeringapproach, refine the experimental methods, and develop appropriate modeling tools. The researchwill also explore fast, high power recharging that may enable rapid cycling. The second stage ofthe research will create improvements using extended surfaces that may increase heat transfer byincreasing the area of the melt surface and enabling efficient evacuation of the liquid PCM. Theengineering methods will include development of reduced order models of the dynPCM coolingand recharge cycles, as well as system level models that allow for optimization and systemsintegration. Finally, the research will build a prototype dynPCM thermal management systemdesignedfor a defense electronics application and demonstrate optimal operation under relevantoperatingconditions. We aim to demonstrate anintegrated dynPCM TMS that achieves coolingpower greater than 100 W/cm2 when the PCM is Paraffin which melts at 46�C and cooling powergreater than 1000 W/cm2 when the PCM is Field#s metal which melts at 62 �C.Approved for Public Release
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 15, 2023
- Source ID
- N000142312425
Entities
People
- William King
Organizations
- Office of Naval Research
- United States Navy
- University of Illinois Urbana–Champaign