Double plate heat exchanger

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,

wherein the first heat transfer plate and the second heat transfer plate are identical,

each of the first heat transfer plate and each of the second heat transfer plate being formed of a single solid plate, and

wherein each of the first and second heat transfer plates has no more than two openings.

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 second heat transfer plate is rotated 180° relative to the first heat transfer plate.

4 . The plate element according to claim 1 , wherein one of the first set of openings is formed in one of the first extension sections arranged at a top of the first heat transfer plate, and the other of the first set of openings is formed in the other of the first extension sections arranged at another, oppositely arranged, end 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 a 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 one of the second extension sections arranged at one end of the second heat transfer plate, and the other of the second set of openings is formed in the other of the second extension sections arranged at another, oppositely arranged, end 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 a 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 volume 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 volume 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 the respective openings from the inner volume 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.