Relieved-channel, bonded heat exchanger

Abstract

A panel assembly for exchanging heat with an ambient environment maintains minimal temperature differential by virtue of operation as a heat pipe apparatus. Panels of a composite material having excellent structural strength and structural stiffness but comparatively modest thermal conductivity are machined as mirror images of one another. Two orthogonal arrays of parallel channels are machined in the faces of two panels, each intersection of channels forming and bounded by pedestals having a lower, broader base with a narrower upper portion extending from a shoulder of the base portion of the pedestals. The pedestals, in turn, form the bounds of the channels, each having a deeper and a narrower aspect extending along the bases of all the pedestals. Channels have a broader aspect extending along near the tops of the pedestals.

1 . An apparatus comprising:
 a panel formed of a composite material comprising a fiber-reinforced matrix;   the panel, machined to provide a first set of channels, parallel to one another, the channels having a first portion excavated into an inside surface of the panel to extend comparatively closer to an outside surface opposite thereto, and a second portion excavated to extend more shallowly;   a second set of channels extending orthogonally to the first set of channels and parallel to one another, the channels of the second set having a first a portion extending comparatively deeper and closer to an outer surface thereof opposite the second set, a second portion extending a comparatively more shallow, lesser distance toward the outside surface;   the first panel having a plurality of first pedestals formed by excavation of the channels;   a second panel having a plurality of second pedestals formed by excavation of the second panel to be positioned opposite and corresponding to the first pedestals;   a bond formed between first pedestals of the first panel in contact with the second pedestals of the second panel corresponding thereto; and   a working fluid transported by capillary action in the first portions of the channels, and returning as a vapor through the second portions of the channels.