High-frequency, low-temperature regenerative heat exchanger

Abstract

A high-frequency, low-temperature regenerator (12). The regenerator (12) includes a substrate (50) having rare earth material (52) disposed thereon. In a specific embodiment, the substrate (50) has channels or pores (54) therethrough or therein to facilitate gas flow through the regenerator (12). The substrate (50) is constructed from a material, such as polyimide, polyester, or stainless steel, which is sufficient to define the geometry of the regenerator (12). The rare earth material (52) is selected and deposited on the substrate (50) in a layer (52) having thermal penetration depth that is greater than the thickness of the layer (52). The thermal penetration depth is sufficiently high to enable all of the rare earth material (52) to contribute to thermal regeneration at an operating frequency of 30 Hz. In the illustrative embodiment, the thickness of the substrate (50) is less than or equal to approximately 0.001 inches. The layer of rare earth material (52) is approximately 0.0002 inches thick. The substrate (44, 50) includes a stack of plated substrates (44) that are stacked so that spaces (54) exist between the plated substrates (44), which result in a porosity of approximately 15 percent. Dimples, pleats, or other mechanisms in the plated substrates (44) preserve the spaces (54) between the plated substrates (44). In the specific embodiment, the spaces (54) are approximately 0.00025 inches wide, and the working gas is helium.

Dependencies are inferred from the claim text.