Heat exchangers

• US 5,287,918 A
• Filed: 02/24/1993
• Issued: 02/22/1994
• Est. Priority Date: 06/06/1990
• Status: Expired due to Term

• Current Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Inventors: Calderwood, Alistair, Fowler, John O., Boardman, James E., Banks, Simon A., Adderley, Colin I.
• Primary Examiner(s): Flanigan, Allen J.
• Application Number:
  US08/022,880
• Time in Patent Office: 363 Days
• Field of Search: 165/165, 165/166, 165/167, 29/890.042, 228/183
• US Class Current: 165/166
• CPC Class Codes: B21D 53/045 by inflating partially united plates
• CPC Class Codes: B23K 20/18 Zonal welding by interposing weld-preventing substances between zones not to be welded
• CPC Class Codes: F28D 9/0031 the conduits for one heat-exchange medium being formed by paired plates touching each other F28D9/0012, F28D9/0025, F28D9/0081, F28D9/04 take precedence
• CPC Class Codes: F28F 2255/10 made by hydroforming
• CPC Class Codes: F28F 3/14 by separating portions of a pair of joined sheets to form channels, e.g. by inflation manufacture thereof B23P
• CPC Class Codes: F28F 9/026 with static flow control means, e.g. with means for uniformly distributing heat exchange media into conduits
• CPC Class Codes: Y10T 29/49371 with subsequent fluid expansion

Abstract

A compact, high integrity heat exchanger element comprises a core layer through which the heat exchange fluid passes between its inlet and its outlet. The core layer includes a main heat exchange region containing heat exchange surfaces acting as fins. It also has distributor/ collector regions containing flow intercepting features for distributing or collecting the fluid flow over the width of the element. The heat exchange element consists of a minimum of two unitary sheets of metal joined by diffusion bonding in selected places. During manufacture, at least one of the unitary sheets has been superplastically deformed, in at least some of the places where it has not been diffusion bonded, so as to form the core layer complete with all its features in one operation.

Claims

1. A heat exchanger element comprising:

a core layer for flow of heat exchange fluid therethrough, and

fluid inlet and outlet means communicating with the core layer;

the core layer including;

a main heat exchange region containing heat exchange surfaces, and;

a distributor region containing flow intercepting surfaces, the distributor region extending between the main heat exchange region and the inlet means so as to distribute the fluid flow across the extent of the core layer;

the heat exchange element comprising at least two unitary sheets of metal joined together by diffusion bonded joints in selected places, which joints are metallurgically the same as, and exhibit the same strength properties as, the unitary sheets, at least one of the unitary sheets exhibiting superplastic deformation in at least some of the places where it is not diffusion bonded to a neighboring layer, such that the at least one unitary sheet forms the core layer and defines therein the flow intercepting surfaces in the distributor region as well as the heat exchange surfaces in the main heat exchange region, said flow intercepting surfaces in the distributor region comprising corrugations in the at least one superplastically deformed sheet, the corrugations being arranged to convey the heat exchange fluid from the inlet means to the main heat exchange region.

2. A heat exchanger element comprising:

a core layer for flow of heat exchange fluid therethrough, and

fluid inlet and outlet means communicating with the core layer;

the core layer including;

a main heat exchange region containing heat exchange surfaces, and;

a distributor region containing flow intercepting surfaces, the distributor region extending between the main heat exchange region and the inlet means so as to distribute the fluid flow across the extent of the core layer;

the heat exchange element comprising at least two unitary sheets of metal joined together by diffusion bonded joints in selected places, which joints are metallurgically the same as, and exhibit the same strength properties as, the unitary sheets, at least one of the unitary sheets exhibiting superplastic deformation in at least some of the places where it is not diffusion bonded to a neighboring layer, such that the at least one unitary sheet forms the core layer and defines therein the flow intercepting surfaces in the distributor region as well as the heat exchange surfaces in the main heat exchange region, said at least one superplastically deformed sheet having a relatively undeformed transitional portion between a part of itself which is deformed so as to define the heat exchange surfaces in the main heat exchange region and another part of itself which is deformed so as to define the flow intercepting surfaces in the distributor.

3. A heat exchanger element comprising:

a core layer for flow of heat exchange fluid therethrough, and

fluid inlet and outlet means communicating with the core layer;

the core layer including;

a main heat exchange region containing heat exchange surfaces, and;

a distributor region containing flow intercepting surfaces, the distributor region extending between the main heat exchange region and the inlet means so as to distribute the fluid flow across the extent of the core layer;

the heat exchange element comprising at least two unitary sheets of metal joined together by diffusion bonded joints in selected places, which joints are metallurgically the same as, and exhibit the same strength properties as, the unitary sheets, at least one of the unitary sheets exhibiting superplastic deformation in at least some of the places where it is not diffusion bonded to a neighboring layer, such that the at least one unitary sheet forms the core layer and defines therein the flow intercepting surfaces in the distributor region as well as the heat exchange surfaces in the main heat exchange region, said heat exchanger element comprising at least three unitary sheets of metal joined by diffusion bonding in selected places, the flow intercepting surfaces in the distributor region comprising first and second sets of superplastically formed hollow projections, the first set of hollow projections projecting outwardly from a first side of the at least one superplastically deformed sheet, and the second set of hollow projections projecting outwardly from a second side of the at least one superplastically deformed sheet, the ends of the projections being diffusion bonded to the two adjacent sheets.