Heat transfer plate

Abstract

A corrugated heat transfer plate (5, 90, 92). It has opposite front and rear sides (7, 9) and comprises a first end portion (11), a central portion (13) and a second end portion (15). It further comprises first and third port holes (17, 19) arranged in the first end portion (11), second and fourth port holes (27, 29) arranged in the second end portion (15), and a heat transfer area (4) comprising alternatingly arranged elongated ridges (6) and valleys (8) and arranged in the central portion (13). An outer front field gasket groove (36) extends on the front side (7) and encloses the heat transfer area (4), while a rear field sealing area (40) extends on the rear side (9) and encloses the heat transfer area (4). The heat transfer plate (5, 90, 92) is characterized in that it further comprises a fifth port hole (21) arranged in the first end portion (11), a first transfer hole (25) arranged in a first half (h1) of the heat transfer plate (5, 90, 92), and a second transfer hole (35) arranged in a second half (h2) of the heat transfer plate (5, 90, 92). The first and second transfer holes (25, 35) are arranged in the outer front field gasket groove (36) and outside the rear field sealing area (40). The first and second port holes (17, 27) are arranged in the rear field sealing area (40), the third, fourth and fifth port holes (19, 29, 21) are arranged outside the rear field sealing area (40), and the first, second, third, fourth and fifth port holes (17, 27, 19, 29, 21) are arranged outside the outer front field gasket groove (36).

Description

TECHNICAL FIELD

[0001] The present invention relates to a corrugated heat transfer plate. The heat transfer plate can be included in an apparatus for a heat producing process, such as electrolysis. BACKGROUND

[0002] Electrolysis is a well-known process using electricity to chemically decompose an electrolyte. For example, electrolysis can be used to decompose water contained in an electrolyte into hydrogen and oxygen. Heat can be generated during electrolysis, which must be transferred away in order to maintain the efficiency of the electrolysis.

[0003] EP 4012070 discloses a heat exchanger comprising heat transfer plates in a stack. The heat exchanger is adapted to be connected to an electrolysis apparatus, such that a fluid circulating in the electrolysis apparatus passes through the heat exchanger to regulate its temperature. Typically, the temperature of the fluid is gradually increased inside the electrolysis apparatus. Thus, the heat exchanger receives relatively high temperature fluid from the electrolysis apparatus and delivers relatively low temperature fluid to the electrolysis apparatus, which means that there will be a temperature difference across the electrolysis apparatus. This can result in an uneven and non-ideal electrolysis process inside the electrolysis apparatus. The heat exchanger in EP 4012070 is a so-called plate and shell heat exchanger. There are several other types of heat exchangers, such as so-called plate heat exchangers. A plate heat exchanger typically comprises a plurality of corrugated heat transfer plates arranged in alignment in a stack or group. Seals between the heat transfer plates define parallel flow channels between the heat transfer plates, one flow channel between each pair of adjacent heat transfer plates. Two fluids, which have different initial temperatures, can be fed alternately through every second flow channel for transferring heat from one fluid to the other fluid. SUMMARY

[0004] It is an object of the present invention to provide a heat transfer plate in order to enable a reliable and mechanically uncomplicated apparatus comprising said heat transfer plate as part of a stack of corrugated heat transfer plates forming first and second plate interspaces arranged alternately, which apparatus can be used for a heat producing process, such as electrolysis, and which apparatus can allow for a more even and efficient cooling of a fluid, such as an electrolyte, and products formed thereof, in order to enable a high process efficiency. The basic idea of the present invention is to provide a heat transfer plate which can enable cooling in a first interspace such that a heat producing process is efficiently maintained in a second interspace, which heat transfer plate allows for feeding of a fluid to and from the second interspace using the first interspace. Thus, the basic concept of the present invention is to provide a heat transfer plate which enables an apparatus to perform a heat producing process, such as electrolysis, while the apparatus can be used as a conventional heat exchanger in order to provide cooling "integrated" in the heat producing process.

[0005] The heat transfer plate can be used in an apparatus for producing hydrogen.

[0006] As the heat transfer plate according to the present application is not arranged to be used alone, but as a building block of the above described apparatus, the advantages of the different features and embodiments of the heat transfer plate first manifest themselves when the heat transfer plate is installed in the apparatus.

[0007] The heat transfer plate according to the present application is corrugated and has opposite front and back sides. The heat transfer plate comprises a first end portion, a central portion and a second end portion arranged successively along a longitudinal centre axis of the heat transfer plate. The heat transfer plate further comprises first and third port holes arranged within the first end portion, and second and fourth port holes arranged within the second end portion. Furthermore, the heat transfer plate further comprises a heat transfer area arranged within the central portion. The heat transfer area is provided with a heat transfer corrugation pattern comprising elongated ridges and valleys arranged alternately when seen from the front side of the heat transfer plate. The heat transfer plate further comprises an annular outer front field gasket groove extending on the front side and surrounding the heat transfer area, and an annular back field sealing area extending on the back side and surrounding the heat transfer area. The heat transfer plate is characterized in that it further comprises a fifth port hole arranged within the first end portion, a first transfer hole arranged within a first half of the heat transfer plate comprising the first end portion, and a second transfer hole arranged within a second half of the heat transfer plate comprising the second end portion. The first and second transfer holes are arranged within the outer front field gasket groove and outside the back field sealing area. The first and second port holes are arranged within the back field sealing area, while the third, fourth and fifth port holes are arranged outside the back field sealing area. The first, second, third, fourth and fifth port holes are arranged outside the outer front field gasket groove.

[0008] The outer front field gasket groove is arranged to receive an outer front field gasket component configured to seal between the heat transfer plate and an adjacent heat transfer plate arranged on the front side of the heat transfer plate. Similarly, the back field sealing area is arranged to accommodate a seal, such as a weld or a back field gasket component, configured to seal between the heat transfer plate and an adjacent heat transfer plate arranged on the back side of the heat transfer plate.

[0009] The first and second halves of the heat transfer plate are arranged on opposite sides of a transversal centre axis of the heat transfer plate.

[0010] The ridges and valleys of the heat transfer corrugation pattern can extend in and between an imaginary first plane and an imaginary second plane, the imaginary first plane and the imaginary second plane facing the front side and the back side of the heat transfer plate, respectively.

[0011] It should be emphasized that "annular" does not necessarily mean circular, but can be any "closed" shape, such as an ellipse, a polygon or any combination thereof. Likewise, "ring" does not necessarily mean circular, but can mean any "closed" shape, such as an ellipse, a polygon or any combination thereof.

[0012] Furthermore, it should be emphasized that herein, when it is said that for example detail A "extends along" detail B, detail A can extend immediately adjacent to detail B, or can extend at a distance from detail B, either parallel or not parallel to detail B.

[0013] Thus, the heat transfer plate of the present application enables a device comprising at least five ports, which can be necessary for performing a heat producing process such as electrolysis, and having integrated cooling functionality. The provision of first and second transfer holes within the outer front field gasket groove and outside the rear field sealing area enables the use of a first gap for feeding fluid into and out of a second gap, as will be discussed below, in a device comprising the heat transfer plate.

[0014] The heat transfer plate can be such that a sixth port hole is arranged within the second end portion. The sixth port hole can be arranged outside the outer front field gasket groove and outside the rear field sealing area like the third, fourth and fifth port holes, in order to enable the formation of two inlet ports and two outlet ports for a second fluid in a device comprising the heat transfer plate.

[0015] The heat transfer plate can further comprise a seventh port hole arranged within the first end portion and an eighth port hole arranged within the second end portion. The seventh and eighth port holes can be arranged within the rear field sealing area and outside the outer front field gasket groove like the first and second port holes, in order to enable the formation of two inlet ports and two outlet ports for a first fluid in a device comprising the heat transfer plate. Such a configuration can enable more efficient cooling if the first fluid is a cooling fluid.

[0016] The first, third, fifth and seventh port holes can be mirror images of the second, fourth, sixth and eighth port holes, respectively, across a transversal centre axis of the heat transfer plate. Furthermore, the first, second, third and fourth port holes can be mirror images of the seventh, eighth, fifth and sixth port holes, respectively, across a longitudinal centre axis of the heat transfer plate. Such a configuration can enable a device comprising a plurality of heat transfer plates according to the present application "rotated" or "flipped" relative to each other. In a stack of "rotated" heat transfer plates, the heat transfer plates are arranged rear side to front side, and every second heat transfer plate is flipped upside down relative to the remaining heat transfer plates. In a stack of "flipped" heat transfer plates, the heat transfer plates are arranged front side to front side, and every second heat transfer plate is flipped upside down relative to the remaining heat transfer plates.

[0017] The outer front field gasket groove of the heat transfer plate can comprise separate first and second long side portions and separate first and second short side portions. The long side portions can extend along a longitudinal center axis of the heat transfer plate, while the short side portions can each connect the first and second long side portions. A distance between the first and second short side portions, which distance is measured parallel to the longitudinal center axis, can vary along a transverse center axis of the heat transfer plate. The transverse center axis of the heat transfer plate extends perpendicular to the longitudinal center axis of the heat transfer plate. As an example, depending on the design of the rest of the heat transfer plate, the short side portions of the outer front field gasket groove can be distanced from each other or bulge towards each other when seen from the center of the heat transfer plate. Such a design can improve fluid collection and fluid distribution across the heat transfer plate.

[0018] The heat transfer plate can further comprise annular third, fourth, fifth and sixth back ring sealing areas surrounding the third, fourth, fifth and sixth port holes, respectively. One of the third and fifth back ring sealing areas can further surround the first transfer hole, and one of the fourth and sixth back ring sealing areas can further surround the second transfer hole. Each back ring sealing area can be arranged to accommodate a seal, such as a weld or a back ring gasket component, configured to seal between the heat transfer plate and an adjacent heat transfer plate arranged at the back side of the heat transfer plate. A seal surrounding both one port hole and one transfer hole can define a flow path between the two.

[0019] The heat transfer plate according to any of the preceding claims, wherein the back field sealing area comprises an annular back field gasket groove. The back field gasket groove can be arranged to receive a back field gasket component configured to seal between the heat transfer plate and an adjacent heat transfer plate arranged at the back side of the heat transfer plate. Sealing between heat transfer plates in the form of a gasket can facilitate maintenance of a device comprising the gasket and the heat transfer plates.

[0020] The front field gasket groove and the back field sealing area can be at least partially aligned and comprise opposite sides of a same section of the heat transfer plate. If the back field sealing area is arranged to accommodate a weld, the section of the heat transfer plate can extend in the second plane; and if the back field sealing area comprises a back field gasket groove, the section can extend between the first and second planes, or possibly intermediate the first and second planes.

[0021] The heat transfer plate can be designed such that the heat transfer area comprises a middle portion extending along the longitudinal center axis. At least a majority of the ridge extending at least partially within the middle portion can have a locally reduced height within the middle portion. In a device comprising the heat transfer plate, such a design can enable the formation of a recirculation channel at the middle portion of the heat transfer area at the front side of the heat transfer plate. The recirculation channel can enable recirculation of the second fluid in the second gap of the device, thereby optimizing a heat production process in the device, such as electrolysis.

[0022] The intermediate portion can extend in different positions. According to an embodiment of the application, the heat transfer area comprises a first and a second field, the first and second field extending on opposite sides of an imaginary first line extending along a longitudinal centre axis of the heat transfer plate. The first field comprises a first ridge and a first valley of the ridges and valleys, and the second field comprises a second ridge and a second valley of the ridges and valleys. The first ridge and the first valley within the first field and the second ridge and the second valley within the second field are inclined in opposite directions relative to the imaginary first line. The intermediate portion extends along the imaginary first line and comprises a border between the first field and the second field. According to this embodiment, the first ridge and the second ridge and the first valley and the second valley form an arrow head, the arrow head being arranged along the imaginary first line, and the first ridge and the second ridge having a lower height at the arrow head.

[0023] The intermediate portion can be at least partly coated with an insulating material on the front side of the heat transfer plate. This configuration implies that the heat transfer plate is coated at locations where the ridges have a reduced height, i.e. at the recirculation channel. In a device comprising the heat transfer plate, the coating can inhibit heat generating processes in the intermediate portion, which can facilitate recirculation of the second fluid in the second gap of the device.

[0024] The heat transfer plate can be designed such that at least a majority of the ridges extending from a first outer longitudinal border of the heat transfer area, the first outer longitudinal border extending along a longitudinal centre axis, have a locally reduced height within a first outer longitudinal portion of the heat transfer area. The first outer longitudinal portion can extend along and comprise the first outer longitudinal border. In a device comprising the heat transfer plate, this design can enable formation of a recirculation channel at the first outer longitudinal portion of the heat transfer area on the front side of the heat transfer plate. The recirculation channel can enable recirculation of the second fluid in the second gap of the device, which can optimize heat generating processes, such as electrolysis, in the device.

[0025] The first outer longitudinal portion can be at least partly coated with an insulating material on the front side of the heat transfer plate. This configuration implies that the heat transfer plate is coated at locations where the ridges have a reduced height. In a device comprising the heat transfer plate, the coating can inhibit heat generating processes in the first outer longitudinal portion, which can facilitate recirculation of the second fluid in the second gap of the device.

[0026] The heat transfer area can comprise a second, opposite outer longitudinal portion of similar configuration, the second outer longitudinal portion extending along and comprising a second outer longitudinal border of the heat transfer area.

[0027] The heat transfer plate can be designed such that at least a majority of the ridges extending from a first outer lateral border of the heat transfer area has a locally reduced height within a first outer lateral portion of the heat transfer area, which first outer lateral border intersects an imaginary second line extending parallel to the longitudinal centre axis. The first outer lateral portion can extend along and comprise the first outer lateral border. In the arrangement of the heat transfer plate, such a design can enable the formation of a transfer channel at the first lateral longitudinal portion of the heat transfer area at the front side of the heat transfer plate. The transfer channel can facilitate the collection or distribution of the second fluid in the second gap of the arrangement.

[0028] The heat transfer area can comprise an oppositely configured second outer lateral portion.

[0029] The heat transfer plate can further comprise a first lateral ridge intersecting an imaginary third line extending parallel to the longitudinal centre axis, which first lateral ridge extends to and borders on an outer side of the heat transfer corrugation pattern. The first lateral ridge can extend within the outer front field gasket slot. The first lateral ridge can prevent the second fluid from stagnating inside the second gap of the arrangement comprising the heat transfer plate. The first lateral ridge can have a different configuration. As an example, it can possibly extend uninterrupted between the first and second outer longitudinal borders of the heat transfer area. Furthermore, it can be convex outwards or inwards when seen from the centre of the heat transfer plate.

[0030] The heat transfer plate can comprise an oppositely configured second lateral ridge.

[0031] The heat transfer plate can further comprise an annular inner front field gasket slot extending at the front side and surrounding the heat transfer area. The outer front field gasket slot can surround the inner front field gasket slot, and the first and second transfer apertures can be arranged within the inner front field gasket slot. The inner front field gasket slot can be arranged to receive an inner front field gasket component configured to seal between the heat transfer plate and an adjacent heat transfer plate arranged at the front side of the heat transfer plate. The inner front field gasket component can further be configured to engage a membrane arranged to extend within the second gap of the arrangement comprising the heat transfer plate, as will be further set out below.

[0032] The inner front field gasket slot of the heat transfer plate can comprise separate first and second long side portions and separate first and second short side portions. The long side portions can extend along the longitudinal centre axis of the heat transfer plate, and the short side portions can each connect the first and second long side portions. A distance between the first and second short side portions, which distance is measured parallel to the longitudinal centre axis, can vary along a lateral centre axis of the heat transfer plate. The lateral centre axis of the heat transfer plate extends perpendicular to the longitudinal centre axis of the heat transfer plate. As an example, depending on the design of the rest of the heat transfer plate, the short side portions of the inner front field gasket slot can be distanced from each other or convex towards each other when seen from the centre of the heat transfer plate. Such a design can improve fluid collection and fluid distribution across the heat transfer plate.

[0033] The heat transfer plate can further comprise an intermediate corrugation pattern between the inner and outer front field gasket grooves. The intermediate corrugation pattern can serve as a support for the inner and outer front field gasket components arranged in the inner and outer front field gasket grooves. Furthermore, the intermediate corrugation pattern of the heat transfer plate can be arranged to abut and support an adjacent heat transfer plate in a device comprising the heat transfer plate.

[0034] Other objects, features, aspects and advantages of the present application will become apparent to those skilled in the art from the following detailed description, together with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0035] The present application will now be described in more detail, reference being made to the accompanying drawings in which

[0036] Figure 1 a and 1b are schematic perspective views of a portion of a device comprising a heat transfer plate according to the present application in an exploded state, and different fluid paths through the device,

[0037] Figure 2 is a schematic plan view of the front side of the heat transfer plate of the device in Figure 1 a

[0038] Figure 3 is a schematic partial side view of the heat transfer plate in Figure 2

[0039] Figure 4 is a schematic plan view of a portion of the heat transfer plate in Figure 2

[0040] Figure 5 is a schematic partial perspective view of the heat transfer plate in Figure 2

[0041] Figure 6 is another schematic partial perspective view of a portion of the heat transfer plate in Figure 2

[0042] Figure 7 is yet another schematic partial perspective view of a portion of the heat transfer plate in Figure 2

[0043] Figure 8 is a schematic plan view of the back side of the heat transfer plate in Figure 2

[0044] Figure 9 is a schematic plan view of a portion of the device in Figure 1 a

[0045] ​​​​​​​​Figure 10 is Figure 1 a a schematic partial cross-sectional view of a sealing assembly of the device in

[0046] Figure 11 is Figure 10 a schematic partial cross-sectional perspective view of a sealing assembly in

[0047] Figure 12a and 12b are substantially similar perspective views schematically illustrating a portion of a device comprising heat transfer plates according to another embodiment of the application in an exploded state, and different fluid paths through the device,

[0048] Figure 13 is Figure 12a a schematic plan view of the front side of a heat transfer plate of the device in

[0049] Figure 14 is a schematic cross-section of a sealing assembly and two surrounding heat transfer plates, illustrating possible configurations of the sealing assembly, and

[0050] Figure 15 is a schematic plan view of the front side of a heat transfer plate according to an alternative embodiment of the application. DETAILED DESCRIPTION

[0051] Figure 1 a A portion of a device 1 for producing hydrogen by electrolysis, here alkaline water electrolysis, is shown. The device 1 comprises a stack 3 (only partly shown) of substantially similar heat transfer plates 5, each heat transfer plate 5 having a front side 7 and an opposite back side 9. In the stack 3, the heat transfer plates 5 are turned over each other, i.e. front side 7 to front side 7 and back side 9 to back side 9, every second heat transfer plate 5 being turned upside down relative to the remaining heat transfer plates 5. This means that every second heat transfer plate 5 is rotated 180 degrees around a respective longitudinal centre axis L of the heat transfer plate 5, and then 180 degrees around a respective normal axis N of the heat transfer plate 5 relative to the remaining heat transfer plates 5. Figure 2 The heat transfer plates 5 are arranged in the stack 3 in a staggered manner, i.e. the longitudinal centre axis L of each heat transfer plate 5 is offset relative to the longitudinal centre axis L of the adjacent heat transfer plates 5 in the stack 3.

[0052] One heat transfer plate 5 is shown individually in Figure 2 and described in more detail below. It has a first end portion 11, a central portion 13 and a second end portion 15 arranged consecutively along a longitudinal centre axis L of the heat transfer plate 5. The boundaries between the first end portion 11, the central portion 13 and the second end portion 15 are indicated in Figure 2The first end 11 comprises a first port hole 17, a third port hole 19, a fifth port hole 21 and a seventh port hole 23, while the second end 15 comprises a second port hole 27, a fourth port hole 29, a sixth port hole 31 and an eighth port hole 33. The first, third, fifth and seventh port holes 17, 19, 21 and 23 are mirrored with respect to the second, fourth, sixth and eighth port holes 27, 29, 31 and 33 across the transversal centre axis T of the heat transfer plate 5. The first, second, third and fourth port holes 17, 27, 19 and 29 are mirrored with respect to the seventh, eighth, fifth and sixth port holes 23, 33, 21 and 31 across the longitudinal centre axis L of the heat transfer plate 5. Furthermore, the first transfer hole 25 is arranged within a first half h1 of the heat transfer plate 5, while the second transfer hole 35 is arranged within a second half h2 of the heat transfer plate 5, the first and second halves h1 and h2 being arranged on opposite sides of the transversal centre axis T. As can be clearly seen in Figure 2 , the first and second transfer holes 25 and 35 are arranged within the central portion 13 of the heat transfer plate 5 on opposite sides of the longitudinal centre axis L.

[0053] As is common for heat transfer plates, the heat transfer plate 5 is pressed with a corrugation pattern of ridges and valleys with respect to a respective centre extending plane CP of the heat transfer plate 5, which centre extending plane is parallel to Figure 2 , and in Figure 3 , is shown. The corrugation pattern differs within different regions of the heat transfer plate 5. For example, the central portion 13 comprises a heat transfer region 4, which is pressed with a so-called chevron heat transfer corrugation pattern 0. As another example, the outer edge portion 37 of the heat transfer plate 5 is pressed with alternating arranged ridges and valleys extending from the outer edge E of the heat transfer plate 5. As Figure 3 , is shown, the ridges and valleys of the outer edge portion 37 extend in parallel first and second planes pi and p2 and between. The first and second transfer holes 25 and 35 are also provided with corrugations, as is further shown in Figure 5 , for the first transfer hole 25.

[0054] With reference to Figure 4 , as seen from the front side 7 of the heat transfer plate 5, the heat transfer corrugation pattern 0 comprises alternating arranged elongated ridges 6 and valleys 8. The heat transfer region 4 comprises a first field 10 and a second field 12, which extend on opposite sides of an imaginary first line li coinciding with the longitudinal centre axis L of the heat transfer plate 5. A first ridge 6a of the ridges 6 and a first valley 8a of the valleys 8 extend within the first field 10, while a second ridge 6b of the ridges 6 and a second valley 8b of the valleys 8 extend within the second field 12. The first ridge 6a and the first valley 8a within the first field 10, and the second ridge 6b and the second valley 8b within the second field 12, are inclined in opposite directions with respect to the longitudinal centre axis L so as to form pairs of arrows with arrow heads arranged along the longitudinal centre axis L.

[0055] The ridges 6 and valleys 8 of the heat transfer corrugation pattern 0 extend into the first and second planes p1 and p2 in all places outside the middle portion 14, the first outer longitudinal portion 16, the second outer longitudinal portion 18, the first outer transverse portion 20, and the second outer transverse portion 22 of the heat transfer region 4. Figure 3 The middle portion 14 extends parallel to the longitudinal central axis L and includes a boundary 24 between the first and second fields 10 and 12, as well as portions of the first and second fields 10 and 12 arranged adjacent to the boundary 24. The first outer longitudinal portion 16 extends parallel to the longitudinal central axis L and includes a first outer longitudinal boundary 26 (shown in dashed lines) of the heat transfer region 4 and portions of the first field 10 arranged adjacent to the first outer longitudinal boundary 26. The second outer longitudinal portion 18 extends parallel to the longitudinal central axis L and includes a longitudinal boundary 28 (shown in dashed lines) of the second outer heat transfer region 4 and portions of the second field 12 arranged adjacent to the second longitudinal outer boundary 28. The first outer transverse portion 20 extends along the transverse central axis T, has a center protruding toward the center of the heat transfer plate 5, and includes a first transverse boundary 30 (shown in dashed lines) of the heat transfer region 4 and portions of the first and second fields 10 and 12 arranged adjacent to the first transverse boundary 30. Furthermore, the first outer transverse boundary 30 has a center protruding toward the center of the heat transfer plate 5. Furthermore, the first outer lateral boundary 30 extends along the lateral central axis T and thus intersects with the imaginary second line l2, which coincides with the longitudinal central axis L. The second outer lateral portion 22 extends along the lateral central axis T, has a center that protrudes toward the center of the heat transfer plate 5, and includes the boundary 32 of the second lateral boundary heat transfer region 4 (shown in dashed lines) and the portions of the first and second fields 10 and 12 arranged adjacent to the second outer lateral boundary 32. The second outer lateral boundary 32 also has a center that protrudes toward the center of the heat transfer plate 5. The second outer lateral boundary 32 extends along the lateral central axis T and thus intersects with the longitudinal central axis L. Within the middle portion 14, the first outer longitudinal portion 16, the second outer longitudinal portion 18, the first outer lateral portion 20, and the second outer lateral portion 22 of the heat transfer region 4, the ridge 6, including the first and second ridges 6a and 6b, locally has a reduced height. More specifically, within these portions of the heat transfer region 4, the ridges 6 and valleys 8 (including the first and second valleys 8a and 8b) extend between the third plane p3 and the second plane p2. Figure 3 The third plane p3 is arranged between the first and second planes p1 and p2 (in this case, in the middle between them). (In an alternative embodiment, the third plane p3 may be positioned at a different location than the middle between the first and second planes p1 and p2.) Therefore, the valley 8 does not have a reduced depth to avoid forming a bypass channel on the rear side 9 of the heat transfer plate 5. Figure 5 The first outer transverse portion 20 is shown in the image. Figure 6 The middle part 14 is shown in the figure, andFigure 7 A second outer longitudinal portion 18 is shown.

[0056] As mentioned above, with reference to Figure 4 The heat transfer plates 5 in the stack 3 are essentially similar. The only difference between the heat transfer plates 5 in the stack is that every second heat transfer plate 5 comprises a coating of insulating material, such as a ceramic material or a polymer, on the front side 7 within the intermediate portion 14 of the heat transfer area 4, while the remaining heat transfer plates 5 comprise the same coating of insulating material on the front side 7 within the first and second outer longitudinal portions 16 and 18 of the heat transfer area 4. This will be discussed further below.

[0057] With reference again to Figure 2 The heat transfer plate 5 further comprises an annular inner front field gasket groove 34, an outer front field gasket groove 36, and annular first, second, third, fourth, fifth, sixth, seventh and eighth front ring gasket grooves 39a-39h, which all extend on the front side 7. Some sections of the outer front field gasket groove 36 also form part of the first, second, third, fourth, fifth, sixth, seventh and eighth front ring gasket grooves 39a-39h. Furthermore, some sections of some of the front ring gasket grooves 39a-39h also form part of other ones of the front ring gasket grooves 39a-39h. Thus, the outer front field gasket groove 36 and the first, second, third, fourth, fifth, sixth, seventh and eighth front ring gasket grooves 39a-39h are integrally formed. The inner front field gasket groove 34 encloses the heat transfer area 4 as well as the first and second transfer holes 25 and 35. The outer front field gasket groove 36 in turn encloses the inner front field gasket groove 34. The first, second, third, fourth, fifth, sixth, seventh and eighth port holes 17, 27, 19, 29, 21, 31, 23 and 33 are all arranged outside the outer front field gasket groove 36 and are enclosed by respective ones of the first, second, third, fourth, fifth, sixth, seventh and eighth front ring gasket grooves 39a-39h. The intermediate corrugation pattern 38 is provided between the inner and outer front field gasket grooves 34 and 36.

[0058] The outer front field gasket groove 36 comprises, like the inner front field gasket groove 34, opposite first and second long side portions li and l2, which extend at a distance from each other substantially parallel to the longitudinal centre axis L of the heat transfer plate 5. Furthermore, the outer front field gasket groove 36 comprises, like the inner front field gasket groove 34, opposite first and second short side portions si and s2, which extend at a distance from each other along the transverse centre axis T of the heat transfer plate 5 to connect the long side portions li and l2. The first and second short side portions si and s2 are convex outwards when seen from the centre of the heat transfer plate 5.

[0059] Furthermore, the heat transfer plate 5 comprises an annular rear field sealing area 40 extending on the rear side 9. With reference again to Figure 2In the image, the rear side of the rear sealing region 40 is visible, which is included in the annular rear gasket groove 42. Furthermore, the heat transfer plate 5 also includes third, fourth, fifth, and sixth rear ring sealing regions 44, 46, 48, and 50 extending on the rear side 9. Figure 2 In the annular third, fourth, fifth, and sixth rear ring gasket grooves 52, 54, 56, and 58, the corresponding rear sides of the third, fourth, fifth, and sixth rear ring sealing regions 44, 46, 48, and 50 are visible. Some sections of the rear ring gasket groove 42 also form parts of the third, fourth, fifth, and sixth rear ring gasket grooves 52, 54, 56, and 58. Furthermore, some sections of some rear ring gasket grooves 52, 54, 56, and 58 also form parts of the other rear ring gasket grooves in the rear ring gasket grooves 52, 54, 56, and 58. Therefore, the rear ring gasket groove 42 and the third, fourth, fifth, and sixth rear ring gasket grooves 52, 54, 56, and 58 are integrally formed. The rear ring gasket groove 42 surrounds the heat transfer zone 4 and the first, second, seventh, and eighth port holes 17, 27, 23, and 33. The first and second transfer holes 25 and 35, as well as the third, fourth, fifth, and sixth port holes 19, 29, 21, and 31, are all arranged outside the rear gasket groove 42. The third, fourth, fifth, and sixth rear ring gasket grooves 52, 54, 56, and 58 surround the corresponding port holes in the third, fourth, fifth, and sixth port holes 19, 29, 21, and 31. Furthermore, the third rear ring gasket groove 52 surrounds the first transfer hole 25, while the sixth rear ring gasket groove 58 surrounds the second transfer hole 35.

[0060] Here (but not necessarily in alternative embodiments of the invention), the bottom of the inner front gasket groove 34, like the bottom of the outer front gasket groove 36, like the corresponding bottoms of the first, second, third, fourth, fifth, sixth, seventh and eighth front ring gasket grooves 39a-39h, like the bottom of the rear gasket groove 42, like the corresponding bottoms of the third, fourth, fifth and sixth rear ring gasket grooves 52, 54, 56 and 58, extends in the middle between the first and second planes p1 and p2, i.e. in the center plane CP. Figure 3 Along the first and second long sides of the heat transfer plate 5, which extends parallel to the longitudinal central axis L, the outer front gasket groove 36 and the rear gasket groove 42 are aligned such that the bottom of the outer front gasket groove 36 coincides with the bottom of the rear gasket groove 42.

[0061] Refer again Figure 4, the heat transfer plate 5 further comprises first and second transverse ridges 80 and 82, respectively, extending along the transverse centre axis T so as to cross an imaginary third line l3 extending parallel to the longitudinal centre axis L. The first and second transverse ridges 80 and 82 are arranged on opposite sides of the heat transfer area 4, between the heat transfer area 4 and the inner front field gasket groove 34. The first and second transverse ridges 80 and 82 are interrupted so as not to extend in the rear field gasket groove 42 and the third, fourth, fifth and sixth rear ring gasket grooves 52, 54, 56 and 58. The first and second transverse ridges 80 and 82 extend from the centre plane CP to and in the first plane pi Figure 3 As is clear from the figures, the first and second transverse ridges 80 and 82 are convex outwards when seen from the centre of the heat transfer plate 5.

[0062] Referring again to Figure 1 a , the arrangement of heat transfer plates 5 in the stack 3 is between two frame plates F, only one of which is shown. The heat transfer plates 5 within the stack 3 are arranged in pairs, with heat transfer plates 5b and 5c forming one of these pairs and heat transfer plate 5d forming one heat transfer plate of another of these pairs. Each pair of heat transfer plates forms a first gap II between them. Furthermore, a second gap I2 is formed between every two adjacent pairs of heat transfer plates 5. An outer heat transfer plate 5x is arranged between the stack 3 and Figure 1 a The frame plate F visible in the middle can be seen to be similar to the heat transfer plates 5, but it lacks the first and second transfer holes 25 and 35, forms an additional first gap II (labelled IIx) with the heat transfer plate 5a, and a plate pair. Thus, an additional second gap I2 is formed between the heat transfer plate 5a and the heat transfer plate 5b, labelled I2x. An outer heat transfer plate without holes can be arranged between the stack 3 and Figure 1 a another frame plate not visible in the middle. Furthermore, a gasket not shown can be arranged on the inner side of the frame plate F.

[0063] An annular rear field gasket component 41 is arranged within each first gap II to define a first flow channel CI therein. A rubber annular inner front field gasket component 43 is arranged within each second gap I2 to define a second flow channel C2 therein. A separation means enclosing an inner field gasket area surrounded by the inner front field gasket component 43 comprises a hydrogen and oxygen ion permeable membrane 45. The membrane 45 extends within the inner front field gasket component 43 and substantially parallel to the heat transfer plates 5 to divide the corresponding second flow channel C2 into a second primary sub-channel C2P and a second secondary sub-channel C2S, which are parallel and extend on opposite sides of the membrane 45.

[0064] Referring to Figure 8The rear field gasket component 41 is part of a gasket assembly G of rubber that also comprises four annular rear ring gasket components 47 that are integrally formed with the rear field gasket component 41. The rear field gasket component 41 is arranged in a rear field gasket groove 42 of the heat transfer plate 5, while the rear ring gasket components 47 are arranged in respective ones of third, fourth, fifth and sixth rear ring gasket grooves 52, 54, 56 and 58.

[0065] Reference is made to Figure 9 The inner front field gasket component 43 and the separator means (not shown in Figure 9 ) comprising the membrane 45 are part of a seal assembly S. The seal assembly S further comprises eight annular front ring gasket components 49, four annular port hole gasket components 84 arranged within respective ones of the intermediate front ring gasket components 49, an outer front field gasket component 86, an insulating inner sheet 88 extending between the inner and outer front field gasket components 43 and 86, and an insulating outer sheet 51 surrounding and connecting all parts of the seal assembly S. Except for the membrane 45, all parts of the seal assembly S are made of rubber. The inner and outer front field gasket components 43 and 86 are arranged in respective ones of the inner and outer front field gasket grooves 34 and 36 Figure 2 , while the front ring gasket components 49 are arranged in respective ones of first, second, third, fourth, fifth, sixth, seventh and eighth front ring gasket grooves 39a-39h Figure 2 .

[0066] All port hole gasket components 84 have a similar design, which is further illustrated in Figure 10 and 11 . As is clear from these figures, the port hole gasket components 84 protrude a larger distance from the front side f of the outer sheet 51 of the seal assembly S than the other parts of the seal assembly S. Furthermore, a plurality of, here three, fluid flow grooves 95 are included in each port hole gasket component 84. The fluid flow grooves 95 extend radially through the port hole gasket component 84 and from the front side f of the seal assembly S (shown in Figure 9 to the back side of the seal assembly S. The purpose thereof will be clear from the following.

[0067] As is shown in Figure 1 a , in the device 1 each heat transfer plate 5 is joined at the front side 7 with the seal assembly S and at the back side 9 with the gasket assembly G. Reference is made to Figure 2 and Figure 8and gasket assembly G, the back field gasket component 41 surrounds the first, second, seventh and eighth port holes 17, 27, 23 and 33 of the heat transfer plate 5, while the back ring gasket component 47 surrounds the respective one of the third, fourth, fifth and sixth port holes 19, 29, 21 and 31 of the heat transfer plate 5, and the two back ring gasket components 47 also surround the respective one of the first transfer hole 25 and the second transfer hole 35 of the heat transfer plate 5. With reference to Figure 2 and 9 and the seal assembly S, the front ring gasket component 49 is arranged at the respective one of the first, second, third, fourth, fifth, sixth, seventh and eighth port holes 17, 27, 19, 29, 21, 31, 23 and 33 of the heat transfer plate 5. In addition, the port hole gasket component 84 is arranged at the respective one of the third, fourth, fifth and sixth port holes 19, 29, 21 and 31.

[0068] With reference to Figure 1 a and Figure 9 When the number of heat transfer plates 5, the number of gasket assemblies G and the number of seal assemblies S are properly joined to each other in the device 1, each port hole gasket component 84 will pass through the aligned port holes of two adjacent heat transfer plates 5 arranged on the front side f of the outer sheet 51 of the corresponding seal assembly S, and abut against the back side of the other adjacent port hole gasket component 84. Thereby, the port hole gasket component 84 will form four rubber channels or ports through the device 1, more specifically, the second primary inlet port 57p, the second secondary inlet port 57s, the second primary outlet port 59p and the second secondary outlet port 59s, which will be discussed further below. The fluid flow groove 95 of the port hole gasket component 84 will allow fluid to flow into and out of these rubber channels, i.e. the second primary inlet port 57p, the second secondary inlet port 57s, the second primary outlet port 59p and the second secondary outlet port 59s.

[0069] When the device 1 is ready for use, the heat transfer plates 5, as well as the intervening gasket assemblies G and seal assemblies S, are compressed between the frame plates F in order to form the first and second flow channels CI and C2, as well as the port means for transporting the first and second fluids through the device 1. After such compression, each pair of heat transfer plates 5, such as the heat transfer plates 5b and 5c, abut against each other in the contact area, while the contact between the adjacent pair of heat transfer plates 5, such as the heat transfer plates 5c and 5d, is prevented due to the presence of the seal assembly S between the plate pairs. This separation or insulation between the plate pairs is necessary for the device 1 to function properly for electrolysis, which will be discussed further below. The compression is achieved by means of certain tightening means, such as bolts and nuts, which are not shown or further described herein. With reference to Figure 9The porting device includes a first inlet porting device 53 and a first outlet porting device 55 for a first fluid, and a second inlet porting device 57 and a second outlet porting device 59 for a second fluid. In turn, the first inlet porting device 53 includes a first primary inlet port 53p and a first secondary inlet port 53s, the first outlet porting device 55 includes a first primary outlet port 55p and a first secondary outlet port 55s, the second inlet porting device 57 includes a second primary inlet port 57p and a second secondary inlet port 57s, and the second outlet porting device 59 includes a second primary outlet port 59p and a second secondary outlet port 59s.

[0070] Referring to Figure 1 a A first fluid, such as deionized water, for a cooling fluid, is fed into the device 1 via a first inlet device 61 and fed out of the device 1 via a first outlet device 63. The first inlet device 61 includes a first primary inlet 61p and a first secondary inlet 61s, and the first outlet device 63 includes a first primary outlet 63p and a first secondary outlet 63s. Referring to Figure 1 b A second fluid, such as a mixture of water and a caustic agent such as potassium hydroxide, for an electrolyte, is fed into the device 1 via a second inlet device 65 and fed out of the device 1 via a second outlet device 67. The second inlet device 65 includes a second primary inlet 65p and a second secondary inlet 65s, and the second outlet device 67 includes a second primary outlet 67p and a second secondary outlet 67s.

[0071] A first fluid path P1 for conveying the first fluid through the device 1 includes a first primary fluid path P1p and a first secondary fluid path P1s. Referring to Figure 1 a and Figure 9 and the dashed lines, the first primary fluid path P1p extends from the first primary inlet 61p into the first primary inlet port 53p, through the first flow channel C1, into the first primary outlet port 55p, and to the first primary outlet 63p. The first secondary fluid path P1s extends from the first secondary inlet 61s into the first secondary inlet port 53s, through the first flow channel C1, into the first secondary outlet port 55s, and to the first secondary outlet 63s. A second fluid path P2 for conveying the second fluid through the device 1 includes a second primary fluid path P2p and a second secondary fluid path P2s. Referring to Figure 1 b and 9and the dashed line, the second primary fluid path P2p extends from the second primary inlet 65p into the second primary inlet port 57p, into the first flow channel C1 outside the first gap I1, through the respective first transfer hole 25 of every second heat transfer plate (i.e. plate 5a, 5c,...), through the second primary sub-channel C2P, through the respective second transfer hole 35 of every second heat transfer plate (i.e. plate 5a, 5c,...), into the first gap I1 outside the first flow channel C1, into the second primary outlet port 59p and to the second primary outlet 67p. The second secondary fluid path P2s extends from the second secondary inlet 65s into the second secondary inlet port 57s, into the first gap I1 outside the first flow channel C1, through the respective second transfer hole 35 of every second heat transfer plate (i.e. plate 5b, 5d,...), into the second secondary sub-channel C2S, through the second secondary sub-channel C2S, through the respective first transfer hole 25 of every second heat transfer plate (i.e. plate 5b, 5d,...), into the first gap I1 outside the first flow channel C1, into the second secondary outlet port 59s and to the second secondary outlet 67s.

[0072] Referring again to Figure 9 , the first fluid, i.e. the cooling fluid, is conveyed through the device 1 in the ports 53s, 53p, 55s and 55p, while the second fluid, i.e. the electrolyte, is conveyed through the device 1 in the ports 57p, 57s, 59p and 59s. The ports 53s, 53p, 55s and 55p are arranged at a larger distance from the longitudinal centre plane of the device 1 compared to the ports 57p, 57s, 59p and 59s. This means that the cooling fluid is conveyed outside the electrolyte.

[0073] Hence, an electrolysis method is performed by means of the device 1. The method comprises the steps of applying an electric current to the device 1, causing every second heat transfer plate of the device 1 (including the heat transfer plates 5a and 5c) to become an anode and the remaining heat transfer plates of the device 1 (including the heat transfer plates 5b and 5d) to become a cathode. As mentioned above, the sealing assembly S, which insulates between the heat transfer plates 5, is arranged in the second gap I2 of the device 1 (i.e. between the heat transfer plates 5a and 5b and between the heat transfer plates 5c and 5d, etc.) and divides the second flow channel C2 into the second primary sub-channel C2P and the second secondary sub-channel C2S. Thereby, electrolysis can be performed within the second flow channel C2 of the device 1. As also explained above, the ports 57p, 57s, 59p and 59s for the second fluid (i.e. the electrolyte) are “lined” with rubber, which maximizes the risk of short circuits between the heat transfer plates 5, 5a, which can cause the device 1 to malfunction.

[0074] As described above, there are two fluid paths for the second fluid (i.e. electrolyte) through the device 1. Thus, the method comprises the steps of feeding a first portion of the second fluid into the first gap I1 outside the first flow channel C1 and into the second primary sub-channel C2P through the first transfer holes 25 of the heat transfer plates 5a, 5c, etc.; and feeding a second portion of the second fluid into the first gap I1 outside the first flow channel C1 and into the second secondary sub-channel C2S through the second transfer holes 35 of the heat transfer plates 5b, 5d, etc. Furthermore, the method comprises feeding the first and second portions of the second fluid through the second flow channel C2, whereby water in the electrolyte is decomposed into hydrogen and oxygen, and a primary component is formed in the second primary sub-channel C2P and a secondary component is formed in the second secondary sub-channel C2S, the primary component comprising more oxygen and less hydrogen than the secondary component. The primary component of the second fluid is fed into the first gap I1 outside the first flow channel C1 through the second transfer holes 35 of the heat transfer plates 5a, 5c, etc., while the secondary component of the second fluid is fed into the first gap I1 outside the first flow channel C1 through the first transfer holes 25 of the heat transfer plates 5b, 5d, etc. The primary and secondary components are separately discharged from the device 1 via the second primary outlet 67p and the second secondary outlet 67s, respectively. Heat is generated when electrolysis is performed in the second flow channel C2. The method comprises feeding the first fluid (i.e. deionized water) through the first flow channel C1 (i.e. on both sides of the electrolysis channel C2) to efficiently and uniformly dissipate the heat generated by the electrolysis from the device 1.

[0075] The hydrogen and oxygen obtained during electrolysis are released in gaseous form as hydrogen bubbles and oxygen bubbles, which strive to rise under the guidance of the heat transfer corrugation pattern 0 of the heat transfer plates 5, while the second fluid in liquid form falls, so that recirculation is created within the second flow channel C2. Reference is made to Figure 4 In the second secondary sub-channel C2S, the hydrogen bubbles rise within the first and second outer longitudinal portions 16 and 18, while the second fluid in liquid form falls in the middle portion 14 of the heat transfer area 4 of the heat transfer plates 5b, 5d, etc. To promote recirculation inside the second secondary sub-channel C2S, the amount of hydrogen bubbles in the middle portion 14 should be minimized. Therefore, the middle portion 14 of the heat transfer area 4 of the heat transfer plates 5b, 5d, etc. is coated with a ceramic material or a polymer to locally inhibit electrolysis. The second lateral ridge 82 together with the second outer lateral portion 22 of the heat transfer plates 5b, 5d, etc. forms a transfer channel that facilitates distribution of the second fluid entering from the second transfer holes 35 across the entire width of the heat transfer plates 5b, 5d, etc., while the first outer lateral portion 20 together with the first lateral ridge 80 forms a transfer channel that facilitates collection of the second fluid across the heat transfer plates 5b, 5d, etc. and its delivery towards the first transfer holes 25.

[0076] In the second primary subchannel C2P, oxygen bubbles rise in the intermediate section 14, while the second fluid in liquid form descends in the first and second outer longitudinal sections 16 and 18 of the heat transfer area 4 of the heat transfer plates 5a, 5c, etc. In order to promote recirculation inside the second primary subchannel C2P, the amount of oxygen bubbles in the first and second outer longitudinal sections 16 and 18 should be minimized. Therefore, the first and second outer longitudinal sections 16 and 18 of the heat transfer area 4 of the heat transfer plates 5a, 5c, etc. are coated with a ceramic material or a polymer in order to locally inhibit electrolysis. The first lateral ridge 80 together with the first outer lateral section 20 of the heat transfer plates 5a, 5c, etc. forms a transfer channel that facilitates distribution of the second fluid entering from the first transfer hole 25 across the entire width of the heat transfer plates 5a, 5c, etc., while the second outer lateral section 22 together with the second lateral ridge 82 forms a transfer channel that facilitates collection of the second fluid across the heat transfer plates 5a, 5c, etc. and its delivery towards the second transfer hole 35.

[0077] It should be emphasized that the second fluid is referred to as the second fluid even if its properties change when it is supplied to the common device, and that the primary component and the secondary component of the second fluid are referred to as the primary component and the secondary component of the second fluid even if their individual compositions change and are different from each other and from the original second fluid.

[0078] It should be emphasized that all the components required for the device to function properly, such as power sources, connections, lines, control units, valves, pumps, gaskets, sensors, pipes, metering devices, etc. are not described herein or shown in the drawings. Furthermore, the properties of the different components of the device that are not relevant to the present invention are not described or shown herein.

[0079] In the device 1, each sealing assembly S is compressed by the high pressure in order to seal between the surrounding plates 5. In order to keep the wire load in the sealing assemblies S low, the sealing assemblies S comprise two field gaskets in the form of an inner front field gasket part 43 and an outer front field gasket part 86, and therefore, the plates 5 are each formed with an inner front field gasket groove 34 and an outer front field gasket groove 36. Figure 14How the sealing assembly S is constructed is shown. The inner and outer sheets 88 and 51 of the sealing assembly S can be integrally formed as one sheet, or as part of one sheet, which can extend through the inner and outer front gasket components 43 and 86. When the inner and outer sheets 88 and 51 extend through the inner and outer front gasket components 43 and 86, the inner and outer front gasket components 43 and 86 can each comprise two parts, which are arranged to be positioned on opposite sides of the inner and outer sheets 88 and 51. Furthermore, the membrane 45 can extend through the inner front gasket component 43. In the device 1, the outer front gasket component 86 will prevent the second fluid from leaking from the device 1, and maintain the pressure on the inside of the corresponding second flow channel C2. Due to the porosity of the membrane 45, the inner front gasket component 43 can not seal or maintain the pressure between the plates 5 properly. This can result in the second fluid leaking past the inner front gasket component 43, and cause a pressure difference between the inner gasket area enclosed by the inner front gasket component 43 and the area between the inner front gasket component 43 and the outer front gasket component 86.

[0080] Figure 15 A heat transfer plate 5' according to an alternative embodiment of the present application is shown, which is designed to solve any of the problems as described in the paragraphs above, and can replace the plate 5 in the device 1 of Figure 1 a and 1b The heat transfer plate 5' is designed similar to the heat transfer plate 5 described above, but it further comprises a first drain hole 69 and a second drain hole 71 arranged in the central portion 13' of the plate 5', wherein the first drain hole 69 is in the first half h1' of the plate 5', and the second drain hole 71 is in the second half h2' of the plate 5'. The first and second drain holes 69 and 71 are enclosed by the outer front gasket groove 36', and positioned in the intermediate corrugation pattern 38' between the inner and outer front gasket grooves 34' and 36'. Furthermore, the first and second drain holes 69 and 71 are arranged outside the rear gasket groove 42', and enclosed by the third and sixth rear gasket grooves 52' and 58', respectively. The first and second drain holes 69 and 71 have a pressure balancing function to eliminate any pressure difference between the inner gasket area enclosed by the inner front gasket component 43 and the area between the inner front gasket component 43 and the outer front gasket component 86 of the sealing assembly S, which is engaged with the front side 7' of the plate 5'. In a device comprising the plate 5', the inner front gasket component 43 is arranged to allow the second fluid to leak, but prevent the resulting gas from leaking. The gas bubbles will escape the electrolysis area in the easiest way, through the first and second drain holes 69 and 71, which are significantly larger. When the inner front gasket component 43 is not arranged to prevent the second fluid from leaking, it needs less compression. This enables the plate 5' to be in the form of a thin pressed plate, instead of a more rigid, more solid solid plate, which can be exposed to higher pressures without deforming. Figure 9

[0081] ​As is apparent from the above, the device 1 consists of a number of components which are assembled complete before the device 1 is closed for operation. In connection with this closing, air can be trapped inside the device 1, for example in the volume defined by the plate 5', the inner and outer front field gasket parts 43, 86 and the inner sheet 88 of the seal assembly S. When the inner front field gasket part 43 is arranged to allow leakage of the second fluid, this air and any bubbles which still manage to pass through the inner front field gasket part 43 can be forced out through the first and second discharge holes 69 and 71 by the second fluid. The forced-out air and any leaked bubbles can then exit the device 1 via the second primary fluid path P2p and the second secondary fluid path P2s. From a safety perspective, it is advantageous to avoid oxygen being trapped inside the device 1.

[0082] It can be possible to have more or less than two discharge holes in the heat transfer plates. Furthermore, it can be possible to provide one or more discharge holes only for every second plate, depending on the design, if other components of the device 1, such as the seal assembly S and the presence of the inner sheet 88 and the outer sheet 51, are present or not (which can be omitted if the plates are insulated from each other by a coating, as also mentioned below).

[0083] Figure 12a A part of another device 2 for generation of hydrogen by electrolysis is schematically shown. There are similarities between the devices 1 and 2, and the above description applies to some extent also for the device 2. The device 2 comprises a stack 3 of heat transfer plates 90 of a first type and heat transfer plates 92 of a second type. Figure 13 One heat transfer plate 90 is shown separately. The heat transfer plates 90 and 92 differ from the heat transfer plates 5 of the device 1, which means that other components of the device 2 also differ from corresponding components of the device 1. However, the differences between the heat transfer plates 90 and 92 and the heat transfer plates 5 will be focused on in the following.

[0084] The heat transfer plate 90 comprises a first end portion 11 provided with the first, third and fifth port holes 17, 19 and 21 and a second end portion 15 provided with the second, fourth and sixth port holes 27, 29 and 31. The heat transfer plate 90 further comprises a first and a second transfer hole 25 and 35 arranged on the same side of the longitudinal centre axis L of the heat transfer plate 90. Respective centres of the first and second port holes 17 and 27 are arranged along the longitudinal centre axis L. The first, third and fifth port holes 17, 19 and 21 and the first transfer hole 25 are mirrored across the transversal centre axis T of the heat transfer plate 90 with the second, fourth and sixth port holes 27, 29 and 31 and the second transfer hole 35, respectively. Furthermore, the third and fourth port holes 19 and 29 are mirrored across the longitudinal centre axis L with the fifth and sixth port holes 21 and 31, respectively. Furthermore, the heat transfer plate 90 comprises a heat transfer area 4 comprising first, second, third and fourth parallel fields 10, 12, 94 and 96 instead of only the first field 10 and the second field 12 as for the heat transfer plate 5. Thus, the ridges 6 and valleys 8 of the heat transfer pattern 0 form an arrow having arrow heads arranged along three parallel lines, one of which coincides with the longitudinal centre axis L, instead of only along the longitudinal centre axis L. Furthermore, there are three intermediate portions 14 on the heat transfer plate 90 instead of only one, within which the ridges 6 of the heat transfer pattern 0 have a locally reduced height. The central intermediate portion 14 is coated as the first and second outer longitudinal portions 16 and 18 of the heat transfer area 4, whereas the two outer portions of the intermediate portions 14 are not coated.

[0085] The heat transfer plate 92 differs from the heat transfer plate 90 in that the outer intermediate portions 14 of the heat transfer area 4 are coated, whereas the central intermediate portion 14 as well as the first and second outer longitudinal portions 16 and 18 are not coated. Furthermore, the first and second transfer holes 25 and 35 are arranged on opposite sides of the longitudinal centre axis L on the heat transfer plate 92 compared to on the heat transfer plate 90.

[0086] There is a single first fluid path P1 for transporting a first fluid through the device 2. Referring to Figure 12a and the dashed lines, the first fluid path P1 extends from the first inlet 61 into the first inlet port 53, through the first flow channel C1, into the first outlet port 55 and to the first outlet 63. The second fluid path P2 for transporting a second fluid through the device 1 comprises a second primary fluid path P2p and a second secondary fluid path P2s. Referring to Figure 12band the dashed line, the second primary fluid path P2p extends from the second primary inlet 65p into the second primary inlet port 57p, into the first gap 11 outside the first flow channel CI, through the respective first transfer hole 25 of every second heat transfer plate, i.e. heat transfer plate 92, into the second primary sub-channel C2P, through the second primary sub-channel C2P, through the respective second transfer hole 35 of every second heat transfer plate, i.e. heat transfer plate 92, into the first gap 11 outside the first flow channel CI, into the second primary outlet port 59p and to the second primary outlet 67p. The second secondary fluid path P2s extends from the second secondary inlet 65s into the second secondary inlet port 57s, into the first gap 11 outside the first flow channel CI, through the respective second transfer hole 35 of every second heat transfer plate, i.e. heat transfer plate 90, into the second secondary sub-channel C2S, through the second secondary sub-channel C2S, through the respective first transfer hole 25 of every second heat transfer plate, i.e. heat transfer plate 90, into the first gap 11 outside the first flow channel CI, into the second secondary outlet port 59s and to the second secondary outlet 67s.

[0087] Thus, in the device 2, the first fluid is conveyed in the ports 53 and 55, while the second fluid is conveyed in the ports 57p, 57s, 59p and 59s. The ports 57p, 57s, 59p and 59s are arranged at a larger distance from the longitudinal centre plane of the device 2 than the ports 53 and 55. This means that the second fluid is conveyed outside the first fluid. The above described embodiments of the present invention should only be seen as examples. The skilled person realizes that the discussed embodiments can be varied in many ways without departing from the inventive concept.

[0088] In the above described embodiments, the heat transfer plates comprise six or eight port holes. However, the heat transfer plates according to the present invention can comprise more or fewer port holes, even an odd number of port holes, e.g. with respect to a device having a second inlet port means which does not comprise second primary and secondary inlet ports (as in the above described embodiments), but comprises a single second inlet port which only communicates with the second primary and secondary outlet ports.

[0089] In the above described embodiments, the heat transfer plates have a heat transfer area comprising two or four fields. However, the heat transfer plates according to the present invention can comprise more or fewer fields, or three fields.

[0090] The heat transfer plates of the device 1 differ from each other in that they are differently coated. According to an alternative embodiment, the device 1 can comprise heat transfer plates which are all similar and coated in the same way. Such heat transfer plates can be coated at the intermediate portion as well as at the first and second outer longitudinal portions.

[0091] In the embodiments described above, the heat transfer plates are "flipped" relative to each other. The heat transfer plates according to the application can also be designed to be included in a stack with the heat transfer plates "rotated" relative to each other.

[0092] In the embodiments described above, the heat transfer plates are arranged to be non-permanently joined at the front and rear sides with gaskets for sealing between the heat transfer plates in the device and the adjacent heat transfer plates. The heat transfer plates according to the application can instead be arranged to be attached at the rear side to the adjacent heat transfer plates with a permanent seal. On such plates, the bottom of the rear gasket groove can extend in a second plane, i.e. a so-called bottom plane.

[0093] In the embodiments described above, the heat transfer plates comprise an inner front field gasket groove and an outer front field gasket groove for cooperation with a sealing assembly comprising an inner front field gasket part and an outer front field gasket part, and a membrane arranged to be joined with the inner front field gasket part. On the heat transfer plates according to the application, the inner front field gasket groove can be omitted, the heat transfer plates being arranged to cooperate with a sealing assembly that does not comprise an inner front field gasket part but a membrane arranged to be joined directly with the outer front field gasket part.

[0094] In the embodiments described above, the contact between adjacent pairs of heat transfer plates is prevented by the presence of a sealing assembly between the plate pairs, the sealing assembly comprising an insulating outer sheet that connects the inner ring gasket part and the outer front field gasket part. In alternative embodiments, the insulating inner sheet and / or the outer sheet can be omitted, and possibly other parts of the sealing assembly, and the heat transfer plates can instead be appropriately locally coated with an insulating material to prevent contact between adjacent pairs of heat transfer plates. Of course, if the inner sheet 88 and the outer sheet 51 are omitted, the outer front field gasket part 86 need not comprise two parts arranged to be positioned on opposite sides of the inner sheet 88 and the outer sheet 51. Instead, it can comprise a single thicker part.

[0095] In the embodiments described above, the heat transfer plates 5a and 5c etc. are used as anodes and the heat transfer plates 5b and 5d etc. are used as cathodes in order to produce a primary component that contains more oxygen and less hydrogen than the secondary component. In alternative embodiments, the heat transfer plates 5a and 5c etc. can instead be used as cathodes and the heat transfer plates 5b and 5d etc. can be used as anodes in order to produce a secondary component that contains more oxygen and less hydrogen than the primary component.

[0096] The heat transfer plates can be pressed with other corrugation patterns than those specified above. As an example, the heat transfer regions of the heat transfer plates need not be pressed with a so-called chevron corrugation pattern, but can instead be pressed with a corrugation pattern comprising ridges and valleys arranged alternately, which extend substantially parallel to the longitudinal centre axis of the heat transfer plate.

[0097] The heat transfer plates can be included in devices for other types of electrolysis than alkaline water electrolysis, such as chlor-alkali electrolysis. Furthermore, the heat transfer plates can also be included in devices for other applications than electrolysis, such as devices in the form of fuel cells.

[0098] It should be emphasized that the terms first, second, third, etc., primary, secondary, and A, B, C, etc., are used herein only to distinguish between different entities, and do not indicate any mutual order between the entities, or any special characteristics of the entities.

[0099] It should be emphasized that "receiving", "supplying", "communicating", etc., throughout the text means "directly or indirectly receiving", "directly or indirectly supplying", and "directly or indirectly communicating", respectively.

[0100] It should be emphasized that the description of details which are not directly relevant to the present application has been omitted, and that the drawings are merely schematic and not drawn to scale. It should also be said that some of the drawings are more simplified than others. Thus, some components can be shown in one drawing, but omitted in another drawing.

Claims

1. A heat transfer plate (5, 90, 92) which is corrugated, has opposite front (7) and back (9) sides, and comprises a first end portion (11), a central portion (13) and a second end portion (15) arranged successively along a longitudinal centre axis (L) of the heat transfer plate (5, 90, 92), the heat transfer plate (5, 90, 92) further comprising: a first port hole (17) and a third port hole (19) arranged within the first end portion (11); a second port hole (27) and a fourth port hole (29) arranged within the second end portion (15); a heat transfer area (4) provided with a heat transfer corrugation pattern (0) comprising elongated ridges (6) and valleys (8) arranged alternately, when seen from the front side (7), arranged within the central portion (13); an annular outer front field gasket groove (36) extending over the front side (7) and surrounding the heat transfer area (4); and an annular rear field sealing area (40) extending over the rear side (9) and surrounding the heat transfer area (4), characterized by further comprising a fifth port hole (21) arranged within the first end portion (11), a first transfer hole (25) arranged within a first half (h1) of the heat transfer plate (5, 90, 92) comprising the first end portion (11), and a second transfer hole (35) arranged within a second half (h2) of the heat transfer plate (5, 90, 92) comprising the second end portion (15), wherein the first transfer hole (25) and the second transfer hole (35) are arranged within the outer front field gasket groove (36) and outside the rear field sealing area (40), the first port hole (17) and the second port hole (27) are arranged within the rear field sealing area (40), the third port hole (19), the fourth port hole (29) and the fifth port hole (21) are arranged outside the rear field sealing area (40), and the first port hole (17), the second port hole (27), the third port hole (19), the fourth port hole (29) and the fifth port hole (21) are arranged outside the outer front field gasket groove (36).

2. The heat transfer plate (5, 90, 92) according to claim 1, further comprising a sixth port hole (31) arranged within the second end (15), wherein, The sixth port hole (31) is arranged outside the outer front field gasket groove (36) and outside the rear field sealing area (40).

3. The heat transfer plate (5, 90, 92) according to any of the preceding claims, further comprising a seventh port hole (23) arranged within the first end portion (11) and an eighth port hole (33) arranged within the second end portion (15), wherein, The seventh port hole (23) and the eighth port hole (33) are arranged within the rear field sealing area (40) and outside the outer front field gasket groove (36).

4. The heat transfer plate (5, 90, 92) according to any of the preceding claims, wherein The outer front field gasket groove (36) comprises a separate first long side portion (l1) and a second long side portion (l2) extending along a longitudinal centre axis (L) of the heat transfer plate (5, 90, 92), and a separate first short side portion (s1) and a second short side portion (s2) each connecting the first long side portion (l1) and the second long side portion (l2), wherein a distance between the first short side portion (s1) and the second short side portion (s2) varies along a transverse centre axis (T) of the heat transfer plate (5, 90, 92), the distance being measured parallel to the longitudinal centre axis (L).

5. The heat transfer plate (5, 90, 92) according to any of claims 3-4, further comprising a third, fourth, fifth and sixth rear gasket sealing area (44, 46, 48, 50) in the shape of a ring surrounding the third (19), fourth (29), fifth (21) and sixth (31) port hole, respectively, wherein One of the third rear ring sealing area (44) and the fifth rear ring sealing area (48) also surrounds the first transfer hole (25), and one of the fourth rear ring sealing area (46) and the sixth rear ring sealing area (50) also surrounds the second transfer hole (35).

6. The heat transfer plate (5, 90, 92) according to any of the preceding claims, wherein The rear field sealing area (40) is comprised in an annular rear field gasket groove (42).

7. The heat transfer plate (5, 90, 92) according to any of the preceding claims, wherein The heat transfer area (4) comprises a middle portion (14) extending along the longitudinal centre axis (L), and wherein at least a substantial part of the ridges (6) extending at least partly within the middle portion (14) has a locally reduced height within the middle portion (14).

8. The heat transfer plate (5, 90, 92) according to claim 7, wherein The heat transfer area (4) comprises a first field (10) and a second field (12) extending on opposite sides of an imaginary first line (l1) extending along a longitudinal centre axis (L) of the heat transfer plate (5, 90, 92), wherein the first field (10) comprises first ridges (6a) and first valleys (8a) of the ridges (6) and the valleys (8), and the second field (12) comprises second ridges (6b) and second valleys (8b) of the ridges (6) and the valleys (8), wherein the first ridges (6a) and the first valleys (8a) within the first field (10) and the second ridges (6b) and the second valleys (8b) within the second field (12) are inclined in opposite directions relative to the imaginary first line (l1), wherein the middle portion (14) extends along the imaginary first line (l1) and comprises a border (24) between the first field (10) and the second field (12).

9. The heat transfer plate (5, 90, 92) according to any of claims 7-8, wherein The middle portion (14) is at least partly coated with an insulating material on a front side (7) of the heat transfer plate (5, 90, 92).

10. The heat transfer plate (5, 90, 92) according to any of the preceding claims, wherein At least a substantial part of the ridges (6) extending from a first outer longitudinal border (26) of the heat transfer area (4) has a locally reduced height within a first outer longitudinal portion (16) of the heat transfer area (4), the first outer longitudinal border (26) extending along the longitudinal centre axis (L), the first outer longitudinal portion (16) extending along and comprising the first outer longitudinal border (26).

11. The heat transfer plate (5, 90, 92) according to claim 10, wherein The first outer longitudinal portion (16) is at least partly coated with an insulating material on a front side (7) of the heat transfer plate (5, 90, 92).

12. The heat transfer plate (5, 90, 92) according to any of the preceding claims, wherein At least a substantial part of the ridges (6) extending from a first outer transverse border (30) of the heat transfer area (4) has a locally reduced height within a first outer transverse portion (20) of the heat transfer area (4), the first outer transverse border (30) intersecting an imaginary second line (l2) extending parallel to the longitudinal centre axis (L), the first outer transverse portion (20) extending along and comprising the first outer transverse border (30).

13. The heat transfer plate (5, 90, 92) according to any of the preceding claims, further comprising a first transverse ridge (80) intersecting an imaginary third line (l3) extending parallel to the longitudinal centre axis (L), the first transverse ridge (80) extending outside and bordering the heat transfer corrugation pattern (0), and extending within the outer front field gasket groove (36).

14. The heat transfer plate (5, 90, 92) according to any of the preceding claims, further comprising an annular inner front field gasket groove (34) extending on the front side (7) and enclosing the heat transfer area (4), wherein The outer front field gasket groove (36) encloses the inner front field gasket groove (34), and the first and second transfer holes (17, 27) are arranged within the inner front field gasket groove (34).

15. The heat transfer plate (5, 90, 92) according to claim 14, further comprising an intermediate corrugation pattern (38) between the inner front field gasket groove (34) and the outer front field gasket groove (36).

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