Heat exchangers made from additively manufactured sacrificial templates

Abstract

A method of manufacturing a heat exchanger including a heat exchanger core of a first material, the method including additive manufacturing a sacrificial scaffold of a second material, the sacrificial scaffold corresponding in shape to that of the heat exchanger core, coating the sacrificial scaffold with a layer of the first material, and removing the sacrificial scaffold to leave behind the heat exchanger core with an integrated self-aligned passage.

What is claimed is: 
     
         1 . A heat exchanger core comprising:
 a first passage, a second passage, and a third passage, each of the first, second, and third passages being configured to couple an inlet manifold and an outlet manifold,   wherein each of the first, second, and third passages has a wavy pattern along a lengthwise direction of the first, second, and third passages and has a shape in cross-section, the shape having a first line of symmetry corresponding to a major axis of the shape, and a second line of symmetry perpendicular to the first line of symmetry and corresponding to a minor axis of the shape.   
     
     
         2 . The heat exchanger core of  claim 1 , wherein all shapes on planes normal to the lengthwise direction have areas and shapes varying by less than about 10%. 
     
     
         3 . The heat exchanger core of  claim 1 , wherein the shape and area of the cross-section vary by less than 10%. 
     
     
         4 . The heat exchanger core of  claim 1 , wherein the shape has four quadrant splines defined by the first and second lines of symmetry, each quadrant spline having rotation symmetry about a midpoint of the quadrant spline. 
     
     
         5 . The heat exchanger core of  claim 1 , wherein the shape is a tapered ellipse. 
     
     
         6 . The heat exchanger core of  claim 1 , wherein the minor axes of the first, second, and third passages are parallel,
 wherein the second passage is arranged between the first and third passages along a direction of the minor axis, and   wherein for every point along a direction corresponding to a major axis of the shape, a summation of separations between the first and second passages and the second and third passages along a direction of the minor axis is within 10% of a median value.   
     
     
         7 . A heat exchanger core comprising:
 a first set of helices and a second set of helices, each of the first and second set of helices being configured to couple an inlet manifold and an outlet manifold,   wherein each of the first and second set of helices comprise two or more individual helices having cross sections in shapes of ellipses.   
     
     
         8 . The heat exchanger core of  claim 7 , wherein axes of the two or more individual helices are collinear to within about 5° and to within about 5% of a spacing between the first and second set of helices. 
     
     
         9 . A heat exchanger core comprising:
 a first wavy passage;   a second wavy passage;   a third wavy passage; and   a fourth wavy passage,   wherein the first, second, third, and fourth wavy passages connect at a plurality of nodes, and   wherein a cross-sectional area of each node is within 20% of a sum of cross-sectional areas of the first, second, third, and fourth wavy passages.   
     
     
         10 . The heat exchanger core of  claim 9 , wherein the plurality of nodes are collinear and periodically positioned along a length of the first, second, third, and fourth wavy passages.