WO2005015110A1

WO2005015110A1 - Heat exchanger comprising two manifolds

Info

Publication number: WO2005015110A1
Application number: PCT/EP2003/008941
Authority: WO
Inventors: Bjørn VESTERGAARD; James G. Cook
Original assignee: Norsk Hydro Asa
Priority date: 2003-08-07
Filing date: 2003-08-07
Publication date: 2005-02-17
Also published as: AU2003255422A1

Abstract

Heat exchanger comprising two manifolds (12,60) providing an inlet and an outlet respectively for a heat exchanging fluid and a number of heat exchanging tubes extending between the two manifolds, each manifold being composed of a number of juxtapositioned and interconnected parallel pipes (5-7,9-11,61,62), each pair of neighbouring pipes having a common wall wherein the common wall of at least one neighbouring pair of pipes (5,6,10,11,61,62) is formed by a separate partition member (19,67) providing a communication between the two neighbouring pipes.

Description

HEAT EXCHANGER COMPRISING TWO MANIFOLDS

The invention relates to a heat exchanger comprising two manifolds providing an inlet and an outlet respectively for a heat exchanging fluid and a number of heat exchanging tubes extending between the two manifolds, each manifold being composed of amumber of juxtapositioned and interconnected parallel pipes, each pair of neighbouring pipes having a common wall.

Such a heat exchanger is generally known, see e.g. US-A-6 155 340. In such a heat exchanger there is a need to have a number of neighbouring pipes to be interconnected in order to provide sufficient flow capacity of the heat transfer fluidence in the heat exchanger. Otherwise there might be a need to have a fluid communication between some of the some of the neighbouring pipes in the manifold in order to provide a back and forth flow between the two manifolds.

It is therefor an object of the invention to provide a heat exchanger as described above, in which it is easy to provide the right configuration of the manifolds for a number of different applications.

This object is achieved in that the common wall of a least one neighbouring pair of pipes is formed by a separate partition member providing a communication between the two neighbouring pipes.

By providing a separate partition member as a partition wall between two neighbouring pipes it becomes easy to provide either a closed wall or a communication wall, i.e. a wall provided with openings, between two neighbouring pipes, thereby providing a flexible system for designing a heat exchanger.

Other advantages and characteristics will become clear from the following description, reference being made to the annexed drawings, in which,

Fig. 1 is a cross-section of a first embodiment of a heat exchanger according to the invention Fig. 2 is a schematic representation of the heat exchanger shown in Fig. 1 Fig. 3 is a schematic representation of a second embodiment of a heat exchanger according to the invention, Fig. 4 is a schematic representation of a third embodiment of a heat exchanger according to the invention, Fig. 5 is a schematic representation of a fourth embodiment of a heat exchanger according to the invention, Fig. 6 is a schematic representation of a fifth embodiment of a heat exchanger according to the invention, Fig. 7 is a schematic representation of a sixth embodiment of a heat exchanger according to the invention,

Fig. 8 is a perspective view of a manifold with a second embodiment of partition walls according to the invention.

The heat exchanger as shown in Fig. 1 comprises two manifolds or headers 1 and 2 which in the embodiment shown are identical, but which in practise may be different as well. The header 1 comprises three tubes 5, 6 and 7, having a circular cross section, but it may be obvious that any other tube with a suitable cross-section can be used. The three tubes are juxtapositioned in such a way that their axis are lying in one plane 8. In the same way the header 2 is formed of three tubes 9, 10, 11 the axis lines of which are lying in a plane 12.

The planes 8 and 12 are parallel to each other.

In the walls of each tube 5, 6 and 7 a number of slot-like holes 15 has been provided directed towards the plane 12, and the same type of slot-like holes 11 has been provided in the tubes 9, 10 and 11, which are directed to the plane 8. The holes 15, 16 in the tubes

5, 6, 7, 9, 10 and 11 are made in such way that each time one hole 16 is positioned opposite an hole 15.

In each pair of opposite holes 15, 16 a heat exchanging tube 17 has been arranged so as to establish a fluid communication between each opposite pair of tubes 5 and 9, 6 and 10 and 7 and 11. For that purpose the heat exchanging tubes have been connected to the walls of the tubes 5, 6, 7, 9, 10 and 11 in a fluid tight manner.

The tubes 5 and 6 are connected to each other in the region of the plane 8, ... and tubes 6 and 7 are connected to each other in the same plane. In order to establish the connection between the tubes 5 and 6 the walls of these tubes in the region of their contact zone have been provided with longitudinal holes, extending in direction parallel to the axis of the tubes 5 and 6. These holes are made in such a way that each longitudinal hole in tube 5 is opposite a longitudinal hole in tube 6. In each pair of opposite holes a short tube section 18 such as MPE-tube have been inserted and fixed to the walls in a fluid tight manner. In this way a fluid communication has been established between the tubes 5 and 6.

The connection between the tubes 6 and 7 can be made in the same way, but instead of tube sections, use is made of closed sections so that no direct fluid connection is made between tubes 6 and 7. It is however also possible to connect tube 6 to tube 7 in a conventional manner, e.g. by brazing.

Header 2 is made in the same way except that here the direct fluid connection has been established between tubes 10 and 11 by tube sections 19 and no direct fluid connection has been established between tubes 9 and 10.

By providing tube 7 with an inlet and tube 9 with an outlet a serpentine type heat exchanger can be formed, in which an internal fluid is flowing from tube 7 through the heat exchanging tubes 17 to tube 11, next to tube 10 and through heat exchanging tubes 17 to tube 6,next to tube 5 and through heat exchanging tubes to tube 9 from where it leaves the heat exchanger. Heat will be exchanged with another fluid flowing along the outside of the heat exchanging tubes 17. If needed fins can be provided between each pair of justapositioned heat exchanging tubes 17. Heat exchanging tubes 17 may be flat MPE-tubes as conventionally used in heat exchangers. In this case a number of parallel tubes 17 are connecting tube 5 to tube 9, etc. and fins may be provided between the set of tubes connecting tubes 5 to 9 etc.

It is convenient in that it becomes possible to use the same size of MPE-tubing for both, the connection between the two headers and the interconnection between neighbouring tubes in the same header, thereby simplifying the manufacturing and the tooling.

The heat exchanger as described with respect with Fig. 1 can schematically be illustrated as shown in Fig. 2. It is obvious that a serpentine heat exchanger can be made with more than three tubes per header by using the same principles of interconnecting neighbouring tubes in the right way, i.e. by alternating open and closed connections.

Such a heat exchanger having holes 5 each comprising four tubes is schematically illustrated in Fig. 3.

Another type, of heat exchanger is schematically shown in Fig. 3. The heat exchanger has two header tubes 20 and 21 which are interconnected along their length. Header 20 is provided with an inlet and header 21 with an outlet. Each header is provided with a number of holes which are oriented in the same direction in both headers 20 and 21. In the holes the ends of a number of heat exchanging tubes 22 have been inserted and connected in a fluid tight manner to the walls of the header tubes 20, 21.

This type of heat exchanger can be extended by using the above described principle of interconnected header tubes as shown in Fig. 5.

As shown in Fig. 5 four header tubes 30, 31, 32 and 33 have been assembled to a single header unit, U-shaped heat exchanging tube 34 interconnecting header tube 30 and 31 and heat exchanging tube 35 interconnecting header tube 32 and 33. The connection between the header tubes 31 and 32 is made in accordance with the principle described above with respect to Fig. 1.

In Fig. 6 there is shown still another possible configuration for a heat exchanger in which the principle of interconnected head tubes of the invention can be used. In the embodiment shown two rows of header tubes form header 40 and 41 respectively, in which header 40 comprises header tubes 51, 52, 53, 54, 55, 56, 57 and 58 and header tube 41 comprises header tubes 61, 62, 63, 64, 65, 66, 67 and 68. The rows of header tubes 51-58 and 61-68 are positioned opposite each other and a number of heat exchanging tubes 71 is interconnecting header tubes 51 and 61, a number of heat exchanging tubes 72 is interconnecting header tubes 52 and 62, etc.

Header tube 51 is interconnected to header tube 52 in accordance with the principle of the invention, as described above with respect to fig. 1. In the same way the following pairs of header tubes have been interconnected : 54 and 55; 55 and 56; 57 and 58; 61 and 62; 62 and 63; 63 and 64; 65 and 66; 66 and 67; 67 and 68.

By providing an inlet in tube 51 and an outlet in tube 68, serpentine type heat exchanger has been provided having a larger capacity. Moreover, it becomes possible to use this type of heat exchanger as a parallel flow condenser, for which purpose the number of interconnected header tubes in the same header can be adapted to the actual use of the condenser such as it is conventionally done by means of baffles in condenser with single header tube.

A combination of the system used in Fig. 5 and Fig. 6 leads to the configuration shown in Fig. 7 which can further extend by multiplying the unit shown in Fig. 7.

In Fig. 8 there is shown a modified embodiment for using the principle according to the invention. In the example shown, the manifold 60 for the heat exchanger consists of a MPE-like tube consisting of four round tubes, each pair of neighbouring tubes having a common wall section. The central wall section between the two inner tubes 61 and 62 has been deleted and the tube walls are interconnected by bridging pieces 63, 64, each provided with a groove 65, 66, the grooves being opposed to each other. In the grooves 65, 66 a wall section 67 has been inserted which is provided with openings 61, thereby providing a communication between the tubes 61, 62.

The wall section 67 may be brazed to the bridging pieces 63, 63 in order to increase the strength of the manifold. In this way a four-tube-manifold is obtained, which can be used in a system according to Fig. 5.

A more flexible system can be obtained by providing bridging pieces between each pair of neighbouring tubes, comparable to the bridging pieces 63, 64 in Fig. 7. By inserting either completely closed wall sections or wall sections provided with openings, any system shown in Figs. 2-6 can be obtained, just by using the right combination of open or closed wall sections.

A similar solution can be obtained by using so-called folded tubes, in which starting from a sheet material a number of neighbouring tubes has been made by folding the sheet in the right configuration. By including separation wall sections either closed or open in the right way, any type of manifold or header as shown e.g. in Fig. 2-6 can be obtained.

Claims

1. Heat exchanger comprising two manifolds providing an inlet and an outlet respectively for a heat exchanging fluid and a number of heat exchanging tubes extending between the two manifolds, each manifold being composed of a number of juxtapositioned and interconnected parallel pipes, each pair of neighbouring pipes having a common wall, characterized in that the common wall of a least one neighbouring pair of pipes is formed by a separate partition member providing a communication between the two neighbouring pipes.

Heat exchanger according to claim 1, characterized in that in each manifold, each pair of communicating neighbouring pipes is next to at least one pair of non- communicating pipes.

3. Heat exchanger according to claim 1 or 2, characterized in that each manifold comprises a housing having a number of parallel juxtapositioned pipe-like sections, at least a number of these pipe-like sections being in open connections with their adjacent pipe-like sections and mounting means for installing either a wall section or communicating partition members between each pair of adjacent pipe sections in open connection with each other.

4. Heat exchanger according to claim 3, characterized in that each manifold is an extruded part and between adjacent pipe-like sections with open communication there are provided grooves extending in the same direction as the pipe-like sections and suitable for accommodating wall sections and/or communicating partition members to be slided into it.

5. Heat exchanger according to claims 4, characterized in that each manifold is a folded product made from sheet material, provided with a number of pipe sections in open communication, and means provided between adjacent pipe-like sections to accommodate wall sections and/or communicating partition members, either by sliding or enclosing during folding pipes with with round cross-section.

6. Heat exchanger according to any one of the claims 1-5, characterized in that each pipe has a substantially round cross-section.

7. Heat exchanger according to any one of the claims 1-3, characterized in that the manifold is composed of a number of separate pipes, each pipe having a number of openings along a line parallel to the longitudinal direction of the pipe, and two neighbouring pipes being connected to each other providing inserts in the opposed openings.

8. Heat exchanger according to claim 7, characterized in that the inserts are hollow.

9. Heat exchanger according to claim 7 or 8, characterized in that the openings have a substantially square cross-section.

10. Heat exchanger according to claims 8 and 9, characterized in the inserts are small section of MPE-tubes having a flat shape.