Coaxial Gas-Liquid Heat Exchanger With Thermal Expansion Connector

• US 20120222845A1
• Filed: 02/29/2012
• Published: 09/06/2012
• Est. Priority Date: 03/01/2011
• Status: Active Grant

• Current Assignee: Dana Canada Corporation
• Original Assignee: Dana Canada Corporation
• Inventors: Vanderwees, Doug, Cheadle, Brian E., Kinder, Lee M., Bardeleben, Michael
• Granted Patent: US 9,459,052 B2
• Time in Patent Office: Days
• US Class Current: 165/154
• CPC Class Codes: F28D 2021/0082 Charged air coolers cooling of air intake supply F02B29/04
• CPC Class Codes: F28D 21/0003 the heat being recuperated from exhaust gases F28D21/0014 takes precedence
• CPC Class Codes: F28D 7/103 consisting of more than two coaxial conduits or modules of more than two coaxial conduits
• CPC Class Codes: F28D 7/106 consisting of two coaxial conduits or modules of two coaxial conduits
• CPC Class Codes: F28F 13/12 by creating turbulence, e.g. by stirring, by increasing the force of circulation F28F13/08 takes precedence
• CPC Class Codes: F28F 2265/26 for allowing differential expansion between elements floating header box elements F28F9/0236

Abstract

A co-axial gas-liquid heat exchanger such as a charge air cooler comprises at least three concentric tubes forming at least two annular flow passageways. One end of the inner tube is rigidly attached to the middle tube by a thermal expansion connector including an inner connecting portion secured to the first end of the inner tube, an outer connecting portion secured to an inner surface of the middle tube; and one or more webs connecting the inner connecting portion to the outer connecting portion. The webs extend across the annular gas flow passageway but permit the hot gas to flow therethrough. The other end of the inner tube is free to expand in the longitudinal direction, relative to the middle and outer tubes. In some embodiments, the inner connecting portion forms part of a central plug portion which blocks an end of the inner tube.

Claims

1. A concentric tube heat exchanger, comprising:

a) an outer tube having a first end and a second end;

b) an inner tube concentric with the outer tube, the inner tube having a first end and a second end;

c) a middle tube located between, and concentric with, the inner and outer tubes, wherein the middle tube has a first end and a second end, wherein an annular gas flow passage is formed between the inner tube and the middle tube, and wherein an annular coolant flow passage is formed between the middle tube and the outer tube;

d) a thermal expansion connector comprising;

(i) an inner connecting portion rigidly connected to the first end of the inner tube;

(ii) an outer connecting portion rigidly connected to an inner surface of the middle tube; and

(ii) one or more webs extending between the inner connecting portion and the outer connecting portion, wherein each of the one or more webs has an inner end rigidly connected to the inner connecting portion and an outer end rigidly connected to the outer connecting portion, and wherein the one or more webs permit gas to flow into the annular gas flow passage; and

e) a turbulence-enhancing insert provided in the gas flow passageway, wherein the insert is in contact with the outer surface of the inner tube and the inner surface of the middle tube.

2. The concentric tube heat exchanger of claim 1 wherein, in a plane which is transverse to the longitudinal axis of the tubes, the one or more webs have a combined area which is a minor amount of the total area of the gas flow passage.

3. The concentric tube heat exchanger of claim 1, wherein the thermal expansion connector includes at least two of said webs, and wherein said webs are spaced evenly about the circumference of the inner tube.

4. The concentric tube heat exchanger of claim 1, wherein the thermal expansion connector further comprises a blocking portion which blocks the first end of the inner tube, wherein the inner connecting portion and the blocking portion together form a central plug portion which is rigidly connected to the first end of the inner tube.

5. The concentric tube heat exchanger of claim 4, wherein the inner connecting portion and the blocking portion are integrally formed, wherein the central plug portion is in the shape of a cup with the inner connecting portion forming a cylindrical side wall of the cup and the blocking portion forming a bottom of the cup, and wherein the blocking portion is located inwardly of the first end of the inner tube.

6. The concentric tube heat exchanger of claim 5, wherein the cup further comprises a circumferential lip which is distal from the blocking portion and protrudes beyond the end of the inner tube, and wherein the inner ends of the webs are connected to the circumferential lip.

7. The concentric tube heat exchanger according to claim 1, wherein the inner connecting portion of the thermal expansion connector comprises a longitudinally extending cylindrical ring, and wherein the inner ends of the one or more webs are rigidly connected to the inner connecting portion.

8. The concentric tube heat exchanger of claim 7, wherein the inner connecting portion has an outside diameter slightly less than an inside diameter of the first end of the inner tube, wherein the inner connecting portion has an outer surface along which it is rigidly connected to an inner surface of the first end of the inner tube;

or

wherein the inner connecting portion has an inside diameter slightly greater than an outside diameter of the first end of the inner tube, wherein the inner connecting portion has an inner surface along which it is rigidly connected to an outer surface of the first end of the inner tube.

9. The concentric tube heat exchanger of claim 1, wherein the outer connecting portion of the thermal expansion connector comprises a longitudinally extending cylindrical ring, and wherein the outer ends of the one or more webs are rigidly connected to the outer connecting portion.

10. The concentric tube heat exchanger of claim 1, wherein the thermal expansion connector includes a plurality of said webs and a plurality of said outer connecting portions, wherein the outer end of each said web is rigidly connected to one of said outer connecting portions.

11. The concentric tube heat exchanger of claim 1, wherein the thermal expansion connector includes a plurality of said webs and a plurality of said inner connecting portions, wherein the inner end of each said web is rigidly connected to one of said inner connecting portions.

12. The concentric tube heat exchanger of claim 1, wherein each of the ends of the middle tube is adapted for connection to a gas flow conduit, wherein the first end of the inner tube is located inside the middle tube;

and

wherein the inner tube is shorter than the middle tube, and wherein both the first and second ends of the inner tube are located inside the middle tube.

13. The concentric tube heat exchanger of claim 1, wherein the outer tube is shorter than the middle tube, and wherein the outer tube is sealed at its first and second ends to the outer surface of the middle tube.

14. The concentric tube heat exchanger of claim 1, wherein the outer tube is provided with inlet and outlet openings for a liquid coolant.

15. The concentric tube heat exchanger of claim 1, wherein the annular coolant flow passage is provided with a turbulence enhancing insert which is in contact with the outer surface of the middle tube and the inner surface of the outer tube.

16. The concentric tube heat exchanger of claim 15, wherein the turbulence enhancing insert in the annular coolant flow passage is a turbulizer, and wherein the turbulizer is joined to the outer surface of the middle tube by brazing, and is not brazed to the inner surface of the outer tube.

17. The concentric tube heat exchanger of claim 1, wherein the turbulence enhancing insert in the annular gas flow passage is a corrugated fin, and wherein the fin is joined to the inner surface of the middle tube by brazing, and is not brazed to the outer surface of the inner tube.

18. A hot gas cooling system comprising a first concentric tube heat exchanger according to claim 1, and a second concentric tube heat exchanger according to claim 1, wherein the middle tube of the first concentric tube heat exchanger is connected to the middle tube of the second concentric tube heat exchanger so as to provide flow communication between the annular gas flow passage of the first heat exchanger and the annular gas flow passage of the second heat exchanger.

19. The hot gas cooling system of claim 18, wherein an outlet of the annular coolant flow passage of the first concentric tube heat exchanger is in flow communication with the inlet of the annular coolant flow passage of the first concentric tube heat exchanger through a coolant conduit.

20. The hot gas cooling system of claim 19, wherein a heat exchanger for removing heat from said coolant is located in said coolant conduit between the first and second concentric tube heat exchangers.