Method for producing a heat exchanger module with at least two fluid circulation circuits and heat exchanger obtained using this method

Patent metadata

Field	Value
Publication number	US-9908206-B2
Application number	US-201314390613-A
Country	US
Kind code	B2
Filing date	Apr 3, 2013
Priority date	Apr 4, 2012
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

The present invention relates to an novel method of producing heat exchangers having at least two fluid circuits each comprising channels, the method employing diffusion bonding achieved using the hot isostatic pressing (HIP) technique, and to a heat exchanger obtained using this method.

First claim

The invention claimed is:

1. A method for producing a heat exchanger module with at least two fluid circuits each comprising channels, comprising the following steps:
a/ producing at least two separate groups of metal tubes, each tube being of elongated shape and having at least two straight ends, one thereof being open and the other being blind;
b/ aligning each of the two groups with side-by-side positioning of the tubes in at least one row per group;
c/ stacking in a stacking direction to obtain a stack having longitudinal sides and lateral sides, said stacking comprising alternate stacking with top-to-toe positioning of the row(s) of one group and the row(s) of the other group so as to have the rows on top of one another and the blind ends of the tubes of one group arranged on the same lateral side of the stack as the open ends of the tubes of the other group;
d/ offsetting, in a direction at right angles to the stacking direction, of the row(s) of one group relative to the row(s) of the other group, so as to create gaps on each lateral side of the stack, between the blind ends of the tubes of one group and the open ends of the tubes of the other group;
e/ encapsulating the stack by positioning respectively one metal casing on the longitudinal sides of the stack of tubes and metal strips at the end of the offset blind ends of the tubes in each gap created;
f/ welding on the periphery of the casing, each strip and each open end of the tube so as to seal the inside of the encapsulated stack whilst leaving free the open ends of the tubes;
i/ applying a hot isostatic pressing (HIP) cycle at high pressure to the stack, which has been previously degassed, allowing the pressurizing gas to penetrate into all of the tubes via their open ends so as to obtain welding by diffusion between the tubes of the encapsulated stack, the tubes of each group welded by diffusion forming the channels of a fluid circuit of the module.

2. The method as claimed in claim 1 , the casing comprising a through-opening according to which the following steps are carried out between steps f/ and i/:
g/ degassing the interior of the sealed stack via the through-opening;
h/ closing the through-opening.

3. The method as claimed in claim 1 , the tubes produced according to step a/ being straight tubes.

4. The method as claimed in claim 1 , the tubes all being identical to one another.

5. The method as claimed in claim 3 , the tubes of at least one group being straight and having a square cross-section over a majority of their length.

6. The method as claimed in claim 3 , the tubes of at least one group being straight and having a circular cross-section over a majority of their length, wherein their open and blind ends have a square cross-section.

7. The method as claimed in claim 6 , wherein at least one of the ends having the square cross-section being formed by drawing the circular cross-section of the tubes.

8. The method as claimed in claim 7 , wherein at least one of the ends of the square cross-section being produced by welding a solid stopper having an end with a square cross-section.

9. The method as claimed in claim 8 , the stopper being a solid stopper, thus forming a blind end of a tube.

10. The method as claimed in claim 9 , the solid stopper being made of material capable of being dissolved by chemical means.

11. The method as claimed in claim 7 , wherein at least one of the ends having the square cross-section being formed by an end piece having a square cross-section in which the length of the circular cross-section of the tube is press-fitted.

12. The method as claimed in claim 11 , wherein the heat exchanger module further comprises at least one single end piece for a row of tubes, wherein each tube in the row of tubes is press-fitted inside said end piece.

13. The method as claimed in claim 1 , the step e/ being carried out with a casing comprising four metal plates, each being pressed against one of the four longitudinal edges of the stack and the step f/ being carried out by welding the four metal plates in pairs.

14. The method as claimed in claim 1 , the HIP cycle according to step i/ being carried out at a pressure of between 500 and 2000 bar.

15. The method as claimed in claim 1 , comprising a step j/, subsequent to step i/, consisting of a heat treatment designed to restore properties of the metal materials of the components which constitute said module.

16. The method as claimed in claim 1 , comprising a step l/ of transverse boring of the tubes to produce orifices, in the plane of each row and in the vicinity of the lateral sides of the stack, the orifices of each group of tubes, produced by boring, opening out onto one longitudinal side of the stack through the casing, forming a column, the two columns of orifices each being arranged in the vicinity of one lateral side of the stack and opposing one another.

17. The method as claimed in claim 16 , comprising a step m/ of welding a fluid collector to the casing, opposite and around each column of orifices.

18. The method as claimed in claim 2 , comprising a step of cleaning the constituent parts of the encapsulated stack before the degassing step g/.

19. The method as claimed in claim 4 , wherein the tubes of at least one group being straight and having a square cross-section over their length.

20. The method as claimed in claim 4 , wherein the tubes of at least one group being straight and having a circular cross-section over a majority of their length, wherein their open and blind ends have a square cross-section.

Assignees

• Commissariat Energie Atomique

Inventors

• Rigal Emmanuel
• LEIBOLD Jean Marc
• Vidotto Fabien

Classifications

• F28F3/12 Primary

  Elements constructed in the shape of a hollow panel, e.g. with channels {(F28D1/02, F28D1/03 take precedence)} · CPC title

• F28F9/001

  Casings in the form of plate-like arrangements; Frames enclosing a heat exchange core · CPC title

• B23K2201/14

  Operations & Transport · mapped topic

• B23K2201/06

  Operations & Transport · mapped topic

• B23K26/244

  Overlap seam welding · CPC title