# US 10,502,501 B1 · Louvered elliptical tube micro-lattice heat exchangers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,502,501 B1 - Document ID: US10502501B1 - Status: Granted - Kind: B1 - Application number: 14/676,794 - Filed: 2015-04-01 - Granted: 2019-12-10 - Earliest claimed: 2015-04-01 - Assignees: HRL Laboratories, LLC - Applicants: Hrl Laboratories, LLC - Inventors: Christopher S. Roper; Charles Kusuda; Arun Muley; David Page - Web page: https://patentgrep.com/patent/US10502501B1 ## CPC - F28D 1/04: with tubular conduits {(F28D1/0246 takes precedence)} - F28F 1/325: {Fins with openings} - F28D 1/053: the conduits being straight - F28D 7/1615: {the conduits being inside a casing and extending at an angle to the longitudinal axis of the casing; the conduits crossing the conduit for the other heat exchange medium} - F28F 1/02: Tubular elements of cross-section which is non-circular (F28F1/08, F28F1/10 take precedence) - F28F 1/10: Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses (crimped or corrugated elements F28F1/06, F28F1/08) - F28F 9/04: Arrangements for sealing elements into header boxes or end plates {(arrangements for sealing flow lines connectors to header boxes F28F9/0248)} - F28D 2021/0068: {for refrigerant cycles} - F28D 2021/0082: {Charged air coolers} - F28D 2021/0089: {Oil coolers} - F28D 2021/0091: {Radiators} - F28F 2210/02: with particular branching, e.g. fractal conduit arrangements - F28F 2250/02: Streamline-shaped elements - F28D: HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT (fluid heaters having heat generating means and heat transferring means F24H; furnaces F27; details of heat-exchange apparatus of general) - F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16) ## Abstract A heat exchanger with non-circular tubes arranged in a louvered fashion. In one embodiment the tubes include a first plurality of hollow members extending in a first direction, a second plurality of hollow members extending in a second direction different from the first direction, and a third plurality of hollow members extending in a third direction different from the first direction and from the second direction, the hollow members of the first plurality of hollow members, the second plurality of hollow members, and the third plurality of hollow members intersecting at a plurality of hollow nodes. ## Claims ### Claim 1 A heat exchanger comprising a heat exchanger core, the heat exchanger core comprising: a first plurality of hollow members extending in a first direction; and a second plurality of hollow members extending in a second direction different from the first direction, the hollow members of the first plurality of hollow members and the second plurality of hollow members intersecting at a plurality of hollow nodes, each hollow member of the first plurality of hollow members and the second plurality of hollow members having: a length in a longitudinal axis, the length being a largest dimension of each respective one of the hollow members, and at a point along the length, an elongated cross section in a plane perpendicular to the longitudinal axis, the cross section comprising a smallest diameter in a direction parallel to a minor axis, the minor axis being perpendicular to the longitudinal axis, and a largest diameter in a direction parallel to a major axis, the major axis being perpendicular to the longitudinal axis, the minor axis and the major axis lying in the plane of the cross section, the largest diameter being at least 20 percent longer than the smallest diameter, and the largest diameter of a first one of the first plurality of hollow members extending in a different direction from the largest diameter of a second one of the first plurality of hollow members. ### Claim 2 (depends on 1) The heat exchanger of claim 1, wherein: the heat exchanger core further comprises a third plurality of hollow members extending in a third direction different from the first direction and from the second direction; the hollow members of the first plurality of hollow members, the second plurality of hollow members, and the third plurality of hollow members intersect at the plurality of hollow nodes; and each hollow member of the third plurality of hollow members has: a length in a longitudinal axis, the length being a largest dimension of each respective one of the hollow members, and at a point along the length, an elongated cross section in a plane perpendicular to the longitudinal axis, the cross section comprising a smallest diameter in a direction parallel to a minor axis, the minor axis being perpendicular to the longitudinal axis, and a largest diameter in a direction parallel to a major axis, the major axis being perpendicular to the longitudinal axis, the minor axis and the major axis lying in the plane of the cross section, the largest diameter being at least 20 percent longer than the smallest diameter. ### Claim 3 (depends on 2) The heat exchanger of claim 2, wherein the elongated cross section of each hollow member of the first plurality of hollow members and the second plurality of hollow members is an elliptical cross section. ### Claim 4 (depends on 2) The heat exchanger of claim 2, wherein the elongated cross section of each hollow member of the first plurality of hollow members and the second plurality of hollow members has a shape of an airfoil. ### Claim 5 (depends on 2) The heat exchanger of claim 2, wherein the elongated cross section of each hollow member of the first plurality of hollow members and the second plurality of hollow members is a rectangular cross section with rounded corners. ### Claim 6 (depends on 2) The heat exchanger of claim 2, comprising an inlet and an outlet and having a principal external flow direction parallel to a line from the inlet to the outlet, wherein the core comprises: a first region comprising hollow members of the first plurality of hollow members; a second region comprising hollow members of the second plurality of hollow members; and a third region comprising hollow members of the third plurality of hollow members, the second region being between the first region and the third region, and wherein: the major axis of each hollow member of the first region is parallel to the principal external flow direction, the major axis of each hollow member of the second region is oblique to the principal external flow direction, and the major axis of each hollow member of the third region is parallel to the principal external flow direction. ### Claim 7 (depends on 2) The heat exchanger of claim 2, comprising an inlet and an outlet and having a principal external flow direction parallel to a line from the inlet to the outlet, wherein the core comprises: a first region comprising hollow members of the first plurality of hollow members; a second region comprising hollow members of the second plurality of hollow members; and a third region comprising hollow members of the third plurality of hollow members, the second region being between the first region and the third region, and wherein: the major axis of each hollow member of the first region is oblique to the principal external flow direction, the major axis of each hollow member of the second region is parallel to the principal external flow direction, and the major axis of each hollow member of the third region is oblique to the principal external flow direction. ### Claim 8 (depends on 7) The heat exchanger of claim 7, wherein: the angle between the major axis of a hollow member of the first region and the principal external flow direction has the same magnitude as the angle between the major axis of a hollow member of the third region and the principal external flow direction. ### Claim 9 (depends on 2) The heat exchanger of claim 2, wherein the core has: an interior core volume including an interior volume of each of: the first plurality of hollow members; the second plurality of hollow members; and the plurality of hollow nodes; a first surface, the first surface being flat; and a second surface, the second surface being flat and parallel to the first surface, the heat exchanger further comprising a first tubesheet and a second tubesheet, each of the first tubesheet and the second tubesheet having a respective plurality of perforations in fluid communication with the interior core volume. ### Claim 10 (depends on 9) The heat exchanger of claim 9, wherein a first node of the plurality of hollow nodes defines a fourth plurality of hollow members of the first plurality of hollow members, the second plurality of hollow members, and the third plurality of hollow members, the fourth plurality of hollow members intersecting at the first node, the fourth plurality of hollow members consisting of: a fifth plurality of hollow members being nearer than the first node to the first surface; and a sixth plurality of hollow members being nearer than the first node to the second surface; a cross sectional area of the first hollow node being equal to the sum of cross sectional areas of the fifth plurality of hollow members. ### Claim 11 (depends on 9) The heat exchanger of claim 9, wherein a first node of the plurality of hollow nodes defines a fourth plurality of hollow members of the first plurality of hollow members, the second plurality of hollow members, and the third plurality of hollow members, the fourth plurality of hollow members intersecting at the first node, the fourth plurality of hollow members consisting of: a fifth plurality of hollow members being nearer than the first node to the first surface; and a sixth plurality of hollow members being nearer than the first node to the second surface; a cross sectional area of the first hollow node being within 15% of the sum of cross sectional areas of the fifth plurality of hollow members. ### Claim 12 (depends on 9) The heat exchanger of claim 9, wherein a first node of the plurality of hollow nodes defines a fourth plurality of hollow members of the first plurality of hollow members, the second plurality of hollow members, and the third plurality of hollow members, the fourth plurality of hollow members intersecting at the first node, the fourth plurality of hollow members consisting of: a fifth plurality of hollow members being nearer than the first node to the first surface; and a sixth plurality of hollow members being nearer than the first node to the second surface; a cross sectional area of the first hollow node being equal to the greater of: the sum of cross sectional areas of the fifth plurality of hollow members and the sum of cross sectional areas of the sixth plurality of hollow members. ### Claim 13 (depends on 9) The heat exchanger of claim 9, wherein a first node of the plurality of hollow nodes defines a fourth plurality of hollow members of the first plurality of hollow members, the second plurality of hollow members, and the third plurality of hollow members, the fourth plurality of hollow members intersecting at the first node, the fourth plurality of hollow members consisting of: a fifth plurality of hollow members being nearer than the first node to the first surface; and a sixth plurality of hollow members being nearer than the first node to the second surface; a cross sectional area of the first hollow node being within 15% of the greater of: the sum of cross sectional areas of the fifth plurality of hollow members and the sum of cross sectional areas of the sixth plurality of hollow members. ### Claim 14 (depends on 2) The heat exchanger of claim 2, wherein the hollow members of the first plurality of hollow members and the second plurality of hollow members comprise a plurality of dimples. ### Claim 15 (depends on 14) The heat exchanger of claim 14, wherein each of the dimples of the plurality of dimples has a non-circular cross section, taken on a plane tangent to a wall of a hollow member at the dimple. ### Claim 16 (depends on 15) The heat exchanger of claim 15, wherein the cross section of each of the dimples of the plurality of dimples, taken on a plane tangent to a wall of a hollow member at the dimple, has a major axis, and the major axis of the cross section of a first dimple of the plurality of dimples is oblique to the major axis of the cross section of a second dimple of the plurality of dimples. ### Claim 17 (depends on 2) The heat exchanger of claim 2, wherein a set of nodes of the plurality of nodes falls in a plane, and wherein a spacing between centers of adjacent nodes in a first direction in the plane is at least 30% greater than a spacing between centers of adjacent nodes in a second direction, perpendicular to the first direction, in the plane. ### Claim 18 (depends on 1) The heat exchanger of claim 1, wherein the major axis of the first one of the first plurality of hollow members is oblique to the major axis of the second one of the first plurality of hollow members. ### Claim 19 (depends on 1) The heat exchanger of claim 1, wherein the major axis of the first one of the first plurality of hollow members is perpendicular to the major axis of the second one of the first plurality of hollow members. ### Claim 20 (depends on 1) The heat exchanger of claim 1, wherein the first one of the first plurality of hollow members and the second one of the first plurality of hollow members are arranged in a louvered pattern.