Counter-flow ceramic heat exchanger assembly and method
A heat exchanger assembly embodiment includes a plurality of laminated ceramic tape layers having at least one hole surrounded by at least one tape remainder portion. The plurality of layers is arranged in a build direction defined parallel to a counter-flow plane. Each laminated ceramic tape layer is stacked and sintered to define a ceramic core section integrally formed with a first ceramic manifold and a second ceramic manifold. The ceramic core section of the assembly includes a plurality of spaced apart counter-flow plates stacked along a stacking direction normal to the counter-flow plane and the build direction, defining a plurality of flow passages parallel to the counter-flow plane. Each flow passage is in communication with the first manifold and the second manifold. A plurality of counter-flow fins is disposed in at least one of the plurality of flow passages, between adjacent ones of the plurality of counter-flow plates.
1. A green assembly suitable for forming a monolithic heat exchanger assembly, the green assembly comprising:
a first plurality of laminated ceramic tape layers having a plurality of first tape remainder portions partially defining at least two, perpendicular first holes, the plurality of first tape remainder portions comprising at least one unitary horizontally extending portion and vertically extending portion, wherein the first plurality of layers are arranged in a build direction to define a first green manifold section, the build direction defined parallel to a counter-flow plane; and
a second plurality of laminated ceramic tape layers arranged adjacent to the first plurality of laminated ceramic tape layers in the build direction, the second plurality of layers having a plurality of second tape remainder portions partially defining at least one second hole, the plurality of second tape remainder portions comprising at least one unitary horizontally extending portion and vertically extending portion, wherein the second plurality of layers are arranged in the build direction to define a green core section in communication with the first green manifold section;
wherein the green core section of the comprises:
a plurality of spaced apart counter-flow plates stacked along a stacking direction normal to the counter-flow plane and the build direction, the plurality of counter-flow plates defining a plurality of flow passages parallel to the counter-flow plane; and
a plurality of counter-flow fins disposed in at least one of the plurality of flow passages, between adjacent ones of the plurality of counter-flow plates.
2. The green assembly of claim 1 , wherein:
the plurality of second tape remainder portions are aligned in the build direction to define the plurality of spaced apart counter-flow plates and the plurality of counter-flow fins; and
the at least one second hole defines open spaces in the plurality of passages not occupied by the plurality of counter-flow fins.
3. The green assembly of claim 1 , wherein the green core section further comprises:
a plurality of ceramic closure bars disposed between adjacent ones of the plurality of plates so as to provide first flow passages for a first fluid alternating with second flow passages for a second fluid, the first and second passages placed in a counter-flow heat exchange relationship parallel to the counter-flow plane.
4. The green assembly of claim 1 , wherein the first and second pluralities of laminated ceramic tape layers comprise a ceramic selected from a group consisting of: aluminum nitride, alumina, silicon nitride, mullite, and combinations thereof.
5. The green assembly of claim 1 , wherein a geometry of the plurality of counter-flow fins is selected from: offset fins, pin fins, wavy fins, and combinations thereof.
6. The green assembly of claim 1 , wherein the first green manifold is integrally formed to a first end of the integrally formed green core.
7. The green assembly of claim 6 , and further comprising:
a third plurality of laminated ceramic tape layers having a plurality of third tape remainder portions partially defining at least two, perpendicular third holes, the plurality of third tape remainder portions comprising at least one unitary horizontally extending portion and vertically extending portion, wherein the third plurality of layers are stacked in the build direction to define a second green manifold section;
wherein the second green manifold is integrally formed to a second opposing end of the green core section.
8. A method for making a counter-flow heat exchanger assembly, the method comprising:
arranging a first plurality of laminated ceramic tape layers in a build direction to define a first manifold section of the assembly, the first plurality of stacked layers having a plurality of first tape remainder portions partially defining at least two, perpendicular first holes, the plurality of first tape remainder portions comprising at least one unitary horizontally extending portion and vertically extending portion, the build direction defined parallel to a counter-flow plane; and
arranging a second plurality of laminated ceramic tape layers in the build direction to define a core section of the assembly adjacent to and in fluid communication with the first manifold section of the assembly, at least some of the second plurality of laminated ceramic tape layers having a plurality of second tape remainder portions partially defining at least one second hole, the plurality of second tape remainder portions comprising at least one unitary horizontally extending portion and vertically extending portion;
wherein the core section of the assembly comprises:
a plurality of counter-flow plates formed from the at least some of the second plurality of laminated ceramic tape layers having at least one second tape remainder portion, the plurality of counter-flow plates stacked along a stacking direction normal to the counter-flow plane and the build direction, and arranged to define a plurality of flow passages parallel to the counter-flow plane; and
a plurality of counter-flow fins formed from the at least some of the second plurality of laminated ceramic tape layers having at least one second tape remainder portion, the plurality of counter-flow fins disposed between adjacent ones of the plurality of counter-flow plates in at least one of the plurality of flow passages.
9. The method of claim 8 , and further comprising:
aligning the at least one second tape remainder portions in the build direction to define the plurality of spaced apart counter-flow plates and the plurality of counter-flow fins; and
aligning the at least one second holes defining open spaces in the plurality of passages not occupied by the plurality of counter-flow fins.
10. The method of claim 8 , further comprising:
sintering at least the first manifold section and the core section such that the first manifold section and the core section can withstand an inlet temperature of a first fluid or a second fluid of at least 800° C. (1472° F.).
11. The method of claim 8 , wherein the first manifold section is integrally formed to a first end of the integrally formed core.
12. The method of claim 11 , and further comprising:
arranging a third plurality of laminated ceramic tape layers in the build direction stacked to define a second manifold section of the assembly, the third plurality of laminated ceramic tape layers having at least one third hole surrounded by at least one third tape remainder portion; and
integrally forming the second manifold section to a second opposing end of the core section.
13. The method of claim 8 , wherein the first and second pluralities of laminated ceramic tape layers comprise a ceramic selected from a group consisting of: aluminum nitride, alumina, silicon nitride, mullite, and combinations thereof.
14. The method of claim 8 , wherein a geometry of the plurality of counter-flow fins is selected from: offset fins, pin fins, wavy fins, and combinations thereof.