DOUBLE PLATE HEAT EXCHANGER

Abstract

The present invention relates to a plate element (2) having a first heat transfer plate (10) and a second heat transfer plate (20), the first heat transfer plate (10) and the second heat transfer plate (20) being connected to each other to form the plate element (2). Each of the first heat transfer plate (10) and the second heat transfer plate (20) is formed of a plate body with a main part with a heat exchanging portion (40) formed with a surface pattern (45). The first heat transfer plate (10) is formed with a first set of openings (3a, 3d) in first extension sections (50) reaching out from the main part of the plate body, and the second heat transfer plate (20) is formed with a second set of openings (3b, 3c) in second extension sections (50) reaching out from the main part of the plate body. The first extension sections (50) of the first heat transfer plate (10) and the second extension sections (50) of the second heat transfer plate (20) are positioned such that the first set of openings (3a, 3d) and the second set of openings (3b, 3c) are not overlapping. The present invention further relates to a plate heat exchanger (1).

Claims

1. A plate element comprising a first heat transfer plate and a second heat transfer plate, the first heat transfer plate and the second heat transfer plate being connected to each other to form the plate element, each of the first heat transfer plate and the second heat transfer plate being formed of a plate body with a main part with a heat exchanging portion formed with a surface pattern, wherein the first heat transfer plate is formed with a first set of openings in first extension sections reaching out from the main part of the plate body, and the second heat transfer plate is formed with a second set of openings in second extension sections reaching out from the main part of the plate body, wherein the first extension sections of the first heat transfer plate and the second extension sections of the second heat transfer plate are positioned such that the first set of openings and the second set of openings are not overlapping.

2. The plate element according to claim 1, wherein the surface patterns of the respective first heat transfer plate and second heat transfer plate are formed such that they match each other, such that the surface pattern of one plate fits into the surface pattern of the other plate, thereby together appearing as a single surface pattern of the plate element.

3. The plate element according to claim 1, wherein the first heat transfer plate and the second heat transfer plate are identical, and wherein the second heat transfer plate is rotated 180° relative to the first heat transfer plate around a centre axis extending along a length direction of the plate element.

4. The plate element according to claim 1, wherein one of the first set of openings is formed in an extension section arranged at one end of the first heat transfer plate, and the other of the first set of openings is formed in an extension section arranged at another, oppositely arranged, end of the first heat transfer plate, along a line being parallel to a long edge of the first heat transfer plate.

5. The plate element according to claim 4, wherein the oppositely arranged extension sections of the first heat transfer plate are positioned directly opposite each other along the line being parallel to the long edge of the first heat transfer plate.

6. The plate element according to claim 4, wherein the oppositely arranged extension sections of the first heat transfer plate are positioned at diagonally opposite corners of the first heat transfer plate.

7. The plate element according to claim 1, wherein one of the second set of openings is formed in an extension section arranged at one end of the second heat transfer plate, and the other of the second set of openings is formed in an extension section arranged at another, oppositely arranged, end of the second heat transfer plate, along a line parallel to a long edge of the second heat transfer plate.

8. The plate element according to claim 7, wherein the oppositely arranged extension sections of the second heat transfer plate are positioned directly opposite each other along the line being parallel to the long edge of the second heat transfer plate.

9. The plate element according to claim 7, wherein the oppositely arranged extension sections of the second heat transfer plate are positioned at diagonally opposite corners of the second heat transfer plate.

10. The plate element according to claim 1, wherein the first heat transfer plate is made from a first material, and the second heat transfer plate is made from a second material, wherein the second material differs from the first material.

11. The plate element according to claim 10, wherein the first material is a metal and the second material is a plastic material.

12. A heat exchanger comprising two or more stacked plate elements according to claim 1, thereby forming a first flow path (A) along one side of a given plate element and along a connected first neighbouring plate element, between an inlet of the first set of openings and an outlet of the first set of openings, and forming a second flow path (B) along an opposite side of the plate element and along a connected second neighbouring plate element, between an inlet of the second set of openings and an outlet of the second set of openings.

13. The heat exchanger according to claim 12, wherein the plate elements are stacked in such a manner that the first heat transfer plate of a given plate element is arranged adjacent to the first heat transfer plate of a first neighbouring plate element, and the second heat transfer plate of the given plate element is arranged adjacent to the second heat transfer plate of a second neighbouring plate element.

14. The heat exchanger according to claim 12, wherein the plate elements are stacked in such a manner that connecting rims of the second heat transfer plates of the plate elements are sandwiched between portions of two first heat transfer plates of the plate elements, the portions of the two first heat transfer plates facing an inner formed between the extension sections of the two first heat transfer plates.

15. The heat exchanger according to claim 12, wherein the plate elements are stacked in such a manner that connecting rims of the first heat transfer plates of the plate elements are sandwiched between portions of two second heat transfer plates of the plate elements, the portions of the two second heat transfer plates facing an inner formed between the extension sections of the two second heat transfer plates.

16. The heat exchanger according to claim 14, wherein connected first heat transfer plates and connected second heat transfer plates of neighbouring plate elements are sealed at the circumference of the respective openings, thereby separating them from the inner formed between the respective extension sections of the heat transfer plates.

17. The heat exchanger according to claim 12, wherein the extension sections of the first heat transfer plates of the plate elements are positioned such that the respective first sets of openings are aligned, and the extension sections of the second heat transfer plates of the plate elements are positioned such that the respective second sets of openings are aligned.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] FIG. 1 is a general illustration of the principle of a plate kind heat exchanger according to prior art;

[0042] FIG. 2 is a general illustration of the principle of a double plate for a heat exchanger according to prior art;

[0043] FIG. 3 is a general illustration of a first heat transfer plate and a second heat transfer plate formed with extension sections with openings according to an embodiment of the present invention;

[0044] FIG. 4 is a general illustration of a plate element formed of a first heat transfer plate and a second heat transfer plate formed with extension sections with openings according to an embodiment of the present invention;

[0045] FIG. 5 is a general illustration of four plate elements formed of a first heat transfer plate and a second heat transfer plate formed with extension sections with openings according to an embodiment of the present invention and adapted to be stacked into a heat exchanger; and

[0046] FIGS. 6A and 6B are general illustrations of four plate elements stacked into a heat exchanger showing the extension sections.

DETAILED DESCRIPTION

[0047] The detailed description and specific examples, while indicating embodiments of the invention, are given by way of illustration only.

[0048] FIG. 1 illustrates a prior art heat exchanger 1 formed of plate elements 2 connected to neighbouring plate elements 2. Each plate element 2 is formed with openings 3a, 3b, 3c, 3b and a heat exchanging portion 40 with surface patterns 45. When stacked, the connected surface patterns 45 of neighbouring plate elements 2 form flow paths A, B at the respective opposite surfaces of the plate elements 2, a first flow path A at one surface and a second flow path B at the opposite surface, each passing the heat exchanging portion 40 from an inlet to an outlet opening 3a, 3b, 3c, 3b. Further, the openings 3a, 3b, 3c, 3b are aligned forming respectively a first set of openings 3a, 3d defining an inlet and outlet to a first flow path A, and a second set of openings 3b, 3c defining an inlet and outlet 3b, 3c to a second flow path B. The first set of openings 3a, 3d and first flow path A are sealed from the second set of openings 3b, 3c and second flow path B, allowing two fluids to pass through the heat exchanger 1 without the two fluids contacting and mixing. The heat exchanger 1 is adapted for heat to be transferring from the hotter to the colder of the fluids flowing in the flow paths A, B over the plate elements 2.

[0049] The plate elements 2 are of a double wall construction, see FIG. 2, comprising a first heat transfer plate 10 and a second heat transfer plate 20, each comprising a main part including at least the main portion of a central heat exchanging portion 40 provided with surface patterns 45. The first heat transfer plate 10 and the second heat transfer plate 20 are connected over most of their extension, such as at the central heat exchanging portion 40. If one of the heat transfer plates 10, 20 should fail, e.g. by forming cracks, the other will ensure that the fluids will not leak between the first flow path A and the second flow path B. The first heat transfer plate 10 and the second heat transfer plate 20 may not be tightly contacting over the full extension of the plates 10, 20, and the leaking fluid thus could flow into the volume between the two heat transfer plates 10, 20.

[0050] The surface patterns 45 of the respective first heat transfer plate 10 and second heat transfer plate 20 are formed such that they match each other, such that the surface pattern 45 of one plate 10, 20 fits into the surface pattern 45 of the other plate 20, 10, together appearing as a single surface pattern 45 of the plate element 2.

[0051] The surface pattern 45 of the plate element 2 is formed such that if a similar plate element 2, possible turned 180° around an axis through the centre of the plate element 2 in a length direction, then the contacting surface patterns 45 form respectively the first flow path A at the one side of the plate element 2, and the second flow path B at the opposite side of the plate element 2, relative to the first side.

[0052] Each of the plate elements 2 is formed with a first set of openings 3a, 3d as well as a second set of openings 3b, 3c. This introduces a risk of fluid leaking from the first flow path A or the second flow path B to the wrong of the first set of openings 3a, 3d or the second set of openings 3b, 3c. For example, fluid entering the volume between the two heat transfer plates 10, 20 of a plate element 2 may leak into the wrong of the first set of openings 3a, 3d or the second set of openings 3b, 3c.

[0053] FIG. 3 illustrates an embodiment solution where a first heat transfer plate 10 is formed with extension sections 50 reaching out of the main part of the heat transfer plate 10. The openings of a first set of openings 3a, 3d are formed in the extension sections 50.

[0054] In the illustrated embodiment an extension section 50 comprising one of the first set openings 3a is formed at the one end of the first heat transfer plate 10, and the other of the first set openings 3d is formed at the opposite end of the first heat transfer plate 10. The two extension sections 50 may be positioned directly opposite each other along a line parallel to the long edge of the first heat transfer plate 10, and thereby of a heat exchanger in which the first heat transfer plate 10 is arranged. In another embodiment the extension sections 50 may be positioned diagonally with respect to each other, e.g. at diagonally opposite corners of the first heat transfer plate 10, i.e. the opposite corners corresponding to the corners crossed by a diagonal of the first heat transfer plate 10. In a more general embodiment, they may be positioned at any position at the short edge or the long edge of the first heat transfer plate 10.

[0055] The second heat transfer plate 20 is very similar the first heat transfer plate 10, and it is formed in a similar manner, in the sense that a second set of openings 3b, 3c are formed in extension sections 50. In the illustrated embodiment an extension section 50 comprising one of the second set openings 3b is formed at the one end of the second heat transfer plate 20, and the other of the second set openings 3c is formed at the opposite end of the second heat transfer plate 20. Similarly to what is described above with reference to the first heat transfer plate 10, the two extension sections 50 of the second heat transfer plate 20 may be positioned directly opposite each other along a line parallel to the long edge of the second heat transfer plate 20, diagonally, or at any position at the short edge or the long edge of the second heat transfer plate 20.

[0056] The extension sections 50 of the first heat transfer plate 10 and the extension sections 50 of the second heat transfer plate 20 are positioned such that when the first heat transfer plate 10 and the second heat transfer plate 20 are positioned adjacent to each other with matching main parts, the extension sections 50, or at least the respective openings 3a, 3b, 3c, 3d, of the respective heat transfer plates 10, 20, are free from each other or are not contacting/overlapping. This is also illustrated in FIG. 4.

[0057] In general, the extension sections 50 may be formed with surface patterns 45 adapted to connect to surface patterns 45 of extension sections 50 of neighbouring plate elements 2 when stacked into a heat exchanger 1, and may thus form a minor part of the heat exchanging portion 40.

[0058] The extended sections 50 may also be formed with surface patterns adapted to distribute the fluid to the entire width of the plate element 2, and/or similarly to feed it to an opening 3a, 3b, 3c, 3d from the heat exchanging portion 40.

[0059] The main part of the heat transfer plate 10, 20 may be of a regular shape, such as substantially rectangular, oval, pentagonal, hexagonal, etc., where the extension sections 50 form ‘ears’ to the regular shape, or more generally, reach or protrude out from the regular shape.

[0060] The first heat transfer plate 10 and the second heat transfer plate 20, with their respective extension sections 50, may be formed such that when connected into a plate element 2 they appear as a single plate, possible having a combined shape and size similar to that of a standard plate element 2 as known in the prior art. Together they may be substantially rectangular (possible with rounded corners), or having another more regular shape. This is also reflected in that, even though each of the first heat transfer plate 10 and the second heat transfer plate 20 only comprises one set of openings, such as the first heat transfer plate 10 being formed with the first set of openings 3a, 3d and the second heat transfer plate 20 being formed with the second set of openings 3b, 3c, when combined into a plate element 2, the plate element 2 comprises the first set of openings 3a, 3d as well as the second set of openings 3b, 3c.

[0061] In general, the plate elements 2 may be adapted to function as general heat transfer plates of known single and double kind plate heat exchangers 1.

[0062] FIG. 5 illustrates four plate elements 2 to be positioned on top of each other for a plate heat exchanger 1, each formed of a first heat transfer plate 10 and a second heat transfer plate 20, showing the extension sections 50, each formed with an opening 3a, 3b, 3c, 3d.

[0063] In the illustrated embodiment the plate elements 2 are connected such that a first heat transfer plate 10 of a given plate element 2 connects to a first heat transfer plate 10 of one neighbouring plate element 2, and the second heat transfer plate 20 of the given plate element 2 connects to a second heat transfer plate 20 of the other neighbouring plate element 2. The extension sections 50 of the first heat transfer plates 10 are positioned such that the respective first set of openings 3a, 3d of a plate element 2 are aligned with the respective first set of openings 3a, 3d of the neighbouring plate elements 2. Correspondingly, the extension sections 50 of the second heat transfer plates 20 are positioned such that the respective second set of openings 3b, 3c of a plate element 2 are aligned with the respective second set of openings 3b, 3c of the neighbouring plate elements 2.

[0064] The neighbouring plate elements 2 may be fixed, or at least sealed, along the rims 10′, 20′ of the connected heat transfer plates 10, 20.

[0065] FIGS. 6A and 6B illustrate the respective extension sections 50 of four plate elements 2, where FIG. 6A shows the extension sections 50 of the first heat transfer plates 10, and FIG. 6B shows the extension sections 50 of the second heat transfer plates 20.

[0066] Seen in FIG. 6A is the connected second heat transfer plates 20 not reaching the extension sections 50 of the first heat transfer plates 10 with the openings 3a, 3d. In the same manner, in FIG. 6B the connected first heat transfer plates 10 are seen not reaching the openings 3b, 3d, and not reaching the extension portions 50 of the second heat transfer plates 20.

[0067] This construction ensures that no path is formed within the plate elements 2 between the first heat transfer plate 10 and the second heat transfer plate 20 to the respective openings 3a, 3b, 3c, 3d. A fluid leaking, for some reason, into the area between first heat transfer plate 10 and the second heat transfer plate 20 of the plate element 2 will not have contact to the openings 3a, 3b, 3c, 3d, but would either be sealed within the area or leak out at the edges.

[0068] As illustrated, the connected first heat transfer plates 10 and the connected second heat transfer plates 20 are sealed 60 at the circumference of the respective openings 3a, 3b, 3c, 3d, separating them from the inner 55 of the connected extension sections 50. In this embodiment, the connected rims 20′ of the second heat transfer plates 20 are sandwiched between two first heat transfer plates 10 (of the respective and the neighbouring plate element 2).

[0069] Leaking fluid entering the volume between the two heat transfer plates 10, 20 of the neighbouring plate elements 2, thus, would leak to the inner 55 rather than into the openings 3a, 3b, 3c, 3d.

[0070] The connected extension sections 50 may be open at their rims, e.g. formed with drain openings, allowing the fluid leaking into the inner 55 to exit the heat exchanger 1 to be detected.

[0071] In general, the openings 3a, 3b, 3c, 3d are known to form weak areas, in terms of risk of leaking, since this is the areas of the highest pressure differences. The construction according to the present invention prevent mixing of the fluids at the openings 3a, 3b, 3c, 3d. The invention further enables the use of substantially thin heat transfer plates 10, 20, even for high pressure systems, since a deforming or cracking heat transfer plate 10, 20 would not leak to the openings 3a, 3b, 3c, 3d of the other of the flow paths A, B, since they are separated.

[0072] Often two distinct heat exchangers are used, the present invention allows the use of a single heat exchanger.

[0073] While the present disclosure has been illustrated and described with respect to a particular embodiment thereof, it should be appreciated by those of ordinary skill in the art that various modifications to this disclosure may be made without departing from the spirit and scope of the present disclosure.