Anisotropic Ceramic-Metal Heat Exchanger for Cryogenic Applications

DC cryogenic flow systems such as Joule-Thomson (JT) or turbo-Brayton require very high effectiveness heat exchangers to reduce input power, while also requiring the heat exchangers to have low SWaP-C. Cryocoolers for applications approaching 1 K and below demand very high efficiencies when placed on power sensitive platforms. In cryogenic recuperators this is ideally accomplished through transverse conduction of heat from the hot side to the cold side. However, cryogenic heat exchangers are inherently susceptible to performance penalties associated with parasitic heat conduction within the plane of the heat exchanger walls (i.e., parallel to the fluid flow direction). Micro Cooling Concepts, in cooperation with Ceramatec, has developed a concept that utilizes materials with highly anisotropic thermal conductivity to fabricate a microplate heat exchanger with an ultra high effectiveness (>99%) for cryogenic applications with operating temperatures in the 1-10 K range. The proposed cryogenic heat exchanger utilizes a composite assembly of lightweight ceramic and metal. The program will consist of heat exchanger design and analysis, material fabrication, proof-of-concept prototype fabrication, and thermal testing efforts.