# US 2025/0146757 A1 · Heat exchanger with stiffening tube connectors

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- Number: US 2025/0146757 A1
- Document ID: US20250146757A1
- Status: Published application
- Kind: A1
- Application number: 18/386,819
- Filed: 2023-11-03
- Published: 2025-05-08
- Earliest claimed: 2023-11-03
- Assignees: Hamilton Sundstrand Corporation
- Applicants: Hamilton Sundstrand Corporation
- Inventors: James Streeter; Grum T. Ngatu
- Web page: https://patentgrep.com/patent/US20250146757A1

## CPC

- F28D 1/05333: {with multiple rows of conduits or with multi-channel conduits (F28D1/05341 takes precedence)}
- F28F 7/02: Blocks traversed by passages for heat-exchange media {(F28D7/0008 takes precedence)}
- F28F 9/0275: {with multiple branch pipes}
- B33Y 80/00: Products made by additive manufacturing
- F28D 2001/026: {Cores}
- F28F 2210/02: with particular branching, e.g. fractal conduit arrangements
- 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)
- B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING

## Abstract

A heat exchanger having: an upstream header; a downstream header; a core extending from an upstream end at the upstream header to a downstream end at the downstream header, wherein the core includes tubes arranged in a square matrix that defines rows of tubes arranged in a row direction and columns of the tubes arranged in a column direction that is normal to the row direction, each of the tubes defining an upstream end and a downstream end that are spaced apart from each other in a longitudinal direction, and an outer boundary of the core is defined by outer ones of the tubes, wherein each of the tubes is longitudinally divided into tube segments; and tube connectors extending between the tube segments and interconnecting longitudinally and diagonally adjacent ones of the tube segments to stiffen the core.

## Claims

### Claim 1

A heat exchanger, comprising:
an upstream header;
a downstream header;
a core extending from an upstream end at the upstream header to a downstream end at the downstream header,
wherein the core includes tubes arranged in a square matrix that defines rows of tubes arranged in a row direction and columns of the tubes arranged in a column direction that is normal to the row direction,
each of the tubes defining an upstream end and a downstream end that are spaced apart from each other in a longitudinal direction, and
an outer boundary of the core is defined by outer ones of the tubes,
wherein each of the tubes is longitudinally divided into tube segments; and
tube connectors extending between the tube segments and interconnecting longitudinally and diagonally adjacent ones of the tube segments to stiffen the core.

### Claim 2 (depends on 1)

The heat exchanger of claim 1, wherein:
the tube connectors extend longitudinally from a connector upstream end to a connector downstream end, each having:
upstream ports at the upstream end;
downstream ports at the downstream end; and
a longitudinal center having an outer shell, wherein the outer shell defines therein flow paths between the upstream ports and the downstream ports.

### Claim 3 (depends on 2)

The heat exchanger of claim 2, wherein:
an outer boundary of the tube connectors converges at the longitudinal center and diverges toward the upstream and downstream ends.

### Claim 4 (depends on 3)

The heat exchanger of claim 3, wherein:
the tube connectors include four of the upstream ports, four of the downstream ports, and four of the flow paths within the outer shell.

### Claim 5 (depends on 4)

The heat exchanger of claim 4, wherein:
each of the tube connectors has a mixing chamber defined within the outer shell, intermediate of the upstream ends and the downstream ends, and the flow paths are fluidly coupled to each other at the mixing chamber.

### Claim 6 (depends on 4)

The heat exchanger of claim 4, wherein:
the flow paths in each the tube connectors are fluidly isolated from each other within the outer shell.

### Claim 7 (depends on 4)

The heat exchanger of claim 4, wherein:
each of the tubes is longitudinally divided into an upstream segment, a downstream segment, and an intermediate segment therebetween;
the tube connectors include a first upstream set of the tube connectors is that longitudinally between and connects the upstream segment and the intermediate segment of the tubes; and
the tube connectors include a first downstream set of the tube connectors that is longitudinally between and connects the downstream segment and the intermediate segment of the tubes.

### Claim 8 (depends on 7)

The heat exchanger of claim 7, wherein
the core has a rectangular cross section, and the outer boundary defines rectangular outer core faces that define outer core corners of the core, including:
first and second outer core faces that are opposite each other and extend longitudinally from the upstream header to the downstream header and along the row direction; and
third and fourth outer core faces that are opposite each other and extend longitudinally from the upstream header to the downstream header and along the column direction that is normal to the row direction.

### Claim 9 (depends on 8)

The heat exchanger of claim 8, wherein:
longitudinally adjacent to the first upstream set of the tube connectors, the upstream and intermediate segments of the tubes are arranged as first upstream tube clusters defining a 2×2 configuration; and
in each of the first upstream tube clusters, one of the tube connectors interconnects the upstream and intermediate segments of longitudinally and diagonally adjacent ones of the tubes.

### Claim 10 (depends on 8)

The heat exchanger of claim 8, wherein:
longitudinally adjacent to the first downstream set of the tube connectors, the downstream and intermediate segments of the tubes are arranged as first downstream tube clusters defining a 2×2 configuration; and
in each of the first downstream tube clusters, one of the tube connectors interconnects the downstream and intermediate segments of longitudinally and diagonally adjacent ones of the tubes.

### Claim 11 (depends on 8)

The heat exchanger of claim 8, wherein:
at a longitudinal center of the upstream segment of the tubes:
the tubes are arranged as second upstream tube clusters defining a 4×4 configuration; and
each of the second upstream tube clusters has a cluster center along the row and column directions; and
within each of the second upstream tube clusters:
four of the tubes that are located at the cluster center are longitudinally divided into upstream and downstream portions; and
one of the tube connectors interconnects the upstream and downstream portions of longitudinally and diagonally adjacent ones of the tubes within one of the second upstream tube clusters.

### Claim 12 (depends on 8)

The heat exchanger of claim 8, wherein:
at a longitudinal center of the downstream segment of the tubes:
the tubes are arranged as second downstream tube clusters defining a 4×4 configuration; and
each of the second downstream tube clusters has a cluster center along the row and column directions, and
within each of the second downstream tube clusters:
four of the tubes that are located at the cluster center are longitudinally divided into upstream and downstream portions; and
one of the tube connectors interconnects the upstream and downstream portions of longitudinally and diagonally adjacent ones of the tubes within one of the second downstream tube clusters.

### Claim 13 (depends on 8)

The heat exchanger of claim 8, wherein:
within a longitudinal center of the intermediate segment of the tubes, the tubes are arranged as intermediate tube clusters defining a 4×4 configuration,
wherein the intermediate tube clusters define opposite cluster corners, and one of the tubes is located at each of the cluster corners;
within the intermediate tube clusters, interior divided tubes include the tubes that are located at the cluster corners and are spaced apart from the outer core faces,
wherein the interior divided tubes are divided into upstream and downstream portions; and
one of the tube connectors interconnects the upstream and downstream portions of longitudinally and diagonally adjacent ones of the interior divided tubes.

### Claim 14 (depends on 13)

The heat exchanger of claim 13, wherein:
within the intermediate tube clusters, first outer divided tubes include:
the tubes at the cluster corners along the first and second outer core faces that are spaced apart from the outer core corners, and the tubes that are adjacent thereto in the row direction,
wherein the first outer divided tubes are divided into upstream and downstream portions;
one of the connectors interconnects the upstream and downstream portions of longitudinally and diagonally adjacent ones of the first outer divided tubes.

### Claim 15 (depends on 13)

The heat exchanger of claim 13, wherein:
within the intermediate tube clusters, second outer divided tubes include the tubes at the cluster corners along the third and fourth outer core faces that are spaced apart from the outer core corners, and the tubes that are adjacent thereto in the column direction,
wherein the second outer divided tubes are divided into upstream and downstream portions; and
one of the connectors interconnects the upstream and downstream portions of longitudinally and diagonally adjacent ones of the second outer divided tubes.

### Claim 16 (depends on 3)

The heat exchanger of claim 3, wherein:
the upstream header forms an upstream header trunk that subdivides along the longitudinal direction into upstream header branches that are fluidly coupled to the upstream end of the tubes; and
the downstream header forms a downstream header trunk that subdivides along the longitudinal direction into downstream header branches that are fluidly coupled to the downstream ends of the tubes.

### Claim 17 (depends on 1)

The heat exchanger of claim 1, wherein:
every other column of the tubes is offset along the column direction by a distance that is at least a diameter of the tubes.

### Claim 18 (depends on 1)

The heat exchanger of claim 1, wherein:
the tubes have a circular or oval cross section.

### Claim 19 (depends on 1)

The heat exchanger of claim 1, wherein:
the tubes are longitudinally divided so that adjacent ones of the tube connectors in the row direction and the column direction within each of the upstream, downstream and intermediate segments are longitudinally offset from each other.

### Claim 20 (depends on 1)

The heat exchanger of claim 1, wherein:
the core is formed by additive manufacturing.