CN117980537A

CN117980537A - Cooling unit for a box of an electrolysis cell

Info

Publication number: CN117980537A
Application number: CN202280063621.7A
Authority: CN
Inventors: 赫尔格·尼尔森
Original assignee: Danfoss AS
Current assignee: Danfoss AS
Priority date: 2021-12-17
Filing date: 2022-12-14
Publication date: 2024-05-03

Abstract

A cassette (1) for an electrolysis cell is disclosed. The cartridge (1) comprises two cooling plates (2) in contact with each other and forming a cooling flow path (5) between them, and two electrolyte plates (3 a,3 c), each electrolyte plate (3 a,3 c) contacting one of the cooling plates (2). At least a part of the cooling flow path (5) is divided into a plurality of cooling units (17), each cooling unit being connected to the cooling unit supply channel (20) via a cooling unit inlet (21) and to the cooling unit return channel (22) via a cooling unit outlet (23), thereby forming a cooling flow path through each cooling unit (17) from the cooling unit inlet (21) to the cooling unit outlet (23). The cooling units (17) are distributed over the cooling plate (2) in two directions.

Description

Cooling unit for a box of an electrolysis cell

Background

Power-to-X involves Power conversion, energy storage, and a reconverted path using the remaining electrical Power, typically during periods when fluctuating renewable energy sources are generating Power beyond the load.

An electrolyzer is a device that utilizes electricity to drive an electrochemical reaction, such as the decomposition of water into hydrogen and oxygen. The construction of the electrolyzer is very similar to a cell or fuel cell; it consists of anode, cathode and electrolyte.

The hydrogen produced by the electrolyzer is well suited for use in hydrogen fuel cells. The reactions that occur in the electrolyzer are very similar to those in the fuel cell, except that the reactions that occur in the anode and cathode are reversed. In a fuel cell, the anode is where hydrogen is consumed, while in an electrolyzer, hydrogen is produced at the cathode. When the electrical energy required for the electrolysis reaction comes from a renewable energy source, such as wind or solar energy systems, a very sustainable system can be formed.

Direct current electrolysis (efficiency up to 80% to 85%) can be used to produce hydrogen, which in turn can be converted to methane (CH ₄) via methanation, or to methanol along with CO ₂, or to other substances.

The energy (such as hydrogen) produced in this way (e.g. by a wind turbine) may then be stored for later use.

The cells can be configured in a number of different ways and are generally divided into two main designs: monopolar and bipolar. Monopolar designs typically use a liquid electrolyte (alkaline liquid) and bipolar designs use a solid polymer electrolyte (proton exchange membrane).

Alkaline water electrolysis has two electrodes operating in a liquid alkaline electrolyte solution of potassium hydroxide (KOH) or sodium hydroxide (NaOH). The electrodes are separated by a membrane, separating the product gases oxygen O ₂ and hydrogen H ₂, and transporting hydroxide ions (OH ^-) from one electrode to the other.

Other fuels and fuel cells include phosphoric acid fuel cells, molten carbonate fuel cells, solid oxide fuel cells, and all their sub-categories. Such fuel cells are also suitable for use as an electrolyzer.

It is an advantage if the fluid solution operating in the apparatus is within a given temperature to optimize efficiency. It is also an advantage if the device can be compact and expandable.

Disclosure of Invention

It is an object of embodiments of the present invention to provide a cartridge for an electrolysis cell which is easy to produce, efficient and scalable.

The invention provides a cassette for an electrolysis cell comprising two cooling plates which are in contact with each other and form a cooling flow path between them, the cassette further comprising two electrolyte plates each in contact with one of the cooling plates, wherein at least a part of the cooling flow path is divided into a plurality of cooling units, each cooling unit being connected to a cooling unit supply channel via a cooling unit inlet and to a cooling unit return channel via a cooling unit outlet, thereby forming a cooling flow path through each cooling unit from the cooling unit inlet to the cooling unit outlet, wherein the cooling units are distributed over the cooling plates in two directions.

The present invention thus provides a cassette for an electrolysis cell. The cartridge comprises two cooling plates and two electrolyte plates, for example in the form of an anolyte plate and a catholyte plate. The plates are arranged within the cassette such that the two cooling plates are in contact with each other, i.e. face each other, forming a cooling flow path between them. Each of the electrolyte plates contacts or faces one of the cooling plates on the opposite side of the respective cooling plate from the side facing the other cooling plate. Accordingly, an electrolyte path is formed between each cooling plate and the electrolyte plate disposed adjacent thereto. Thus, the cooling fluid flowing through the cooling flow paths provides cooling to the electrolyte fluid flowing in each electrolyte path. This will be described in further detail below.

The cell box may be stacked with several other cell boxes to form an electrolysis cell.

At least a portion of the cooling flow path is divided into a plurality of cooling units. Each cooling unit is connected to a cooling unit supply channel via a cooling unit inlet and to a cooling unit return channel via a cooling unit outlet. Accordingly, a given cooling unit receives cooling fluid from a cooling unit supply channel connected thereto, the cooling fluid passing through the cooling unit and exiting the cooling unit via a cooling unit outlet and entering a cooling unit return channel connected to the cooling unit. In other words, a cooling flow path is defined or formed through the cooling unit from the cooling unit inlet to the cooling unit outlet and thereby from the cooling unit supply channel to the cooling unit return channel. The cooling flow path through the cooling unit forms part of a cooling flow path defined between two cooling plates.

The cooling units are distributed on the cooling plate in two directions. These two directions may be, for example, the length direction of the cooling plate and a transverse direction of the cooling plate substantially perpendicular to the length direction (such as along the width direction of the cooling plate). Alternatively, the two directions may be arranged in different ways. For example, the two directions may be two substantially diagonal directions of the cooling plate. In any case, the cooling units are distributed over the cooling plate in a manner defining a two-dimensional pattern or two-dimensional array. Accordingly, each of these cooling units provides cooling for a small area of the cooling plate, and these small areas are distributed two-dimensionally across the cooling plate. Since each cooling unit receives a supply of cooling fluid directly from the cooling unit supply channel, this allows for a uniform and efficient cooling over the entire area of the cooling plates. This allows for efficient cooling of the anolyte fluid flowing in the anolyte path and the catholyte fluid flowing in the catholyte path. Accordingly, a suitable temperature of the anolyte fluid as well as the catholyte fluid may be obtained therefrom. This ensures that the cell can operate in an efficient manner.

The cooling unit supply channel and/or the cooling unit return channel may be designed in such a way that the obstruction to the cooling fluid flowing therein is minimal. In this case, it is ensured that the cooling fluid can reach all the cooling units quickly and efficiently, and that efficient cooling from all the cooling units can be ensured.

The cartridge may comprise several cooling unit supply channels and/or several cooling unit return channels each supplying or receiving cooling fluid to or from a subset of the cooling units. Alternatively, all cooling units may be connected to a single cooling unit supply channel and a single cooling unit return channel.

The cartridge may further include at least one film covering a region of at least one of the electrolyte plates, and the cooling plate may be formed with cooling units distributed at least in a region arranged to be in contact with a portion of the at least one electrolyte plate covered with the film.

According to this embodiment, the membrane is mounted on at least one of the electrolyte plates. When cassettes are stacked with other cassettes to form an electrolysis cell, the membrane will be disposed between the anolyte plate forming part of one cassette and the catholyte plate forming part of an adjacent cassette. Accordingly, the membrane allows the transport of hydraulic ions (hydronic ion, H ^-) from the catholyte plate to the anolyte plate while keeping the electrolytically generated product gases (e.g., O ₂ and H ₂, respectively) separate.

According to this embodiment, the cooling units are positioned at the cooling plates such that they provide cooling to at least the membrane-mounted portions of adjacent electrolyte plates. The cooling unit is thus arranged as close as possible to the heat source where the electrolysis reaction takes place, i.e. to the active area. This ensures a uniform cooling over the whole active area and thus also a uniform and correct temperature over the whole active area. Accordingly, the correct temperature for the electrolysis reaction is ensured. The uniform temperature across the active area provides the same resistance across the electrolyte plate and provides maximum electrolysis efficiency.

The cooling unit may be formed with a pattern adapted to contact a similar pattern of connected adjacent cooling plates, thereby forming a cooling path within the cooling unit. According to this embodiment, when two cooling plates are connected to form a cooling flow path having a cooling unit therebetween, a pattern formed on one cooling plate is in contact with a pattern formed on the other cooling plate. This creates obstructions within each cooling unit and these obstructions force the cooling fluid to change direction multiple times as it passes through the cooling unit from the cooling unit inlet to the cooling unit outlet. This results in a very efficient cooling.

The pattern may be a corrugated pattern, and the corrugated patterns of adjacent cooling plates connected may be positioned to intersect each other and contact at the intersection points. According to this embodiment, the contact between the patterns formed on the respective cooling plates is in the form of several small contact points distributed substantially uniformly over each cooling unit. This results in a highly uniform and efficient cooling over each cooling unit.

As an alternative to the corrugation pattern, the pattern may be of any other suitable type, such as chevron, dimple form, etc., as long as the pattern causes the cooling fluid to change direction.

According to one embodiment, the pattern may not contact the electrolyte plate at the side of the cooling plate opposite to the side contacting the other cooling plate. In this case, as described above, the pattern affects the flow of the cooling fluid flowing in the cooling unit, but does not affect the flow of the electrolyte fluid in the respective electrolyte flow paths extending between the respective cooling plates and their adjacent electrolyte plates. Accordingly, the electrolyte fluid may pass through the electrolyte flow path substantially unimpeded by the pattern formed on the respective cooling plates.

The contact studs may be distributed on the cooling plate within the cooling unit. The contact posts of each of the two cooling plates may face away from the other cooling plate and be directed towards the respective electrolyte plate positioned adjacent to the cooling plates. According to this embodiment, the contact posts support the plates of the cartridge and ensure a proper distance between the cooling plate and the respective adjacent electrolyte plate over the whole area of the plates, substantially independent of the pressure conditions within the cartridge.

The contact posts may form part of a cooling plate and contact an adjacent electrolyte plate. The contact posts may be fixedly attached to the electrolyte plate, for example by welding or soldering. Alternatively, the contact posts may be urged into contact with the respective electrolyte plates simply by pressing the plates together.

As an alternative to having the contact studs form part of the cooling plate, they may form part of the electrolyte plate and be attached to or pushed into contact with the respective cooling plate. As a further alternative, each contact stud may comprise a portion forming part of the cooling plate and a portion forming part of the adjacent electrolyte plate, and the two portions may be attached to each other or pushed into contact with each other to form the contact stud.

The electrolyte sheet may be formed with electrolyte sheet openings forming porous regions, and the contact posts may be positioned to contact the electrolyte sheet in regions between the electrolyte sheet openings. The porous regions of the electrolyte plate allow gas, for example in the form of product gas (H ₂ and O ₂ respectively), to pass through the electrolyte plate, for example between a membrane on one side of the electrolyte plate and an electrolyte flow path on the other side of the electrolyte plate. By positioning the contact pillars in the areas between the electrolyte plate openings, it is ensured that such transport of gas can take place substantially unimpeded by the contact pillars.

The contact posts may make electrical contact with the electrolyte plate, thereby supplying them with current/voltage.

Each cooling unit supply channel may be connected to a plurality of cooling units via their respective cooling unit inlets. According to this embodiment several cooling units are fluidly connected in parallel to the same cooling unit supply channel. This ensures an efficient and uniform supply of cooling fluid to the cooling unit, which in turn ensures a uniform cooling over the entire area of the cooling plate.

Similarly, each cooling unit return channel may be connected to a plurality of cooling units via their respective cooling unit outlets. This ensures that the cooling fluid leaving the cooling unit is efficiently removed, thereby maintaining an efficient flow of cooling fluid through the cooling unit.

Each electrolyte plate may be formed with at least one electrolyte fluid inlet and at least one gas outlet, and an active area is defined between the at least one electrolyte fluid inlet and the at least one gas outlet, and the area of the cooling plate where the cooling unit is formed may be adapted to be aligned with the active area of the electrolyte plate.

Electrolyte fluid flowing in the cartridge will typically enter the electrolyte flow path (predominantly in liquid form) extending along the electrolyte plate via at least one of the at least one electrolyte fluid inlet and leave the electrolyte flow path (predominantly in gaseous form) via at least one of the at least one gas outlet. Since the active region is located between the at least one electrolyte fluid inlet and the at least one gas outlet, electrolyte fluid flowing in the electrolyte flow path passes through the active region. The active area defines the portion of the cell in which electrolysis occurs. The active area of a given electrolyte sheet may, for example, be provided with electrolyte sheet openings and/or covered by a membrane.

According to this embodiment, the cooling unit is aligned with the active area, thus ensuring cooling of the active area (i.e. the part of the cell where electrolysis takes place). This allows for efficient operation of the electrolyzer.

The cooling unit may be enclosed by a cooling unit wall, wherein the respective cooling unit inlet and cooling unit outlet are formed in the cooling unit wall. The cooling unit walls may, for example, separate the individual cooling units. This is a simple way of providing a cooling unit and its corresponding cooling unit inlet and cooling unit outlet.

The cooling unit wall may be formed as a protrusion in two cooling plates connected to form a flow barrier. According to this embodiment, it is ensured that the cooling units are efficiently sealed to each other, and this is obtained in an easy manner from a manufacturing point of view.

Drawings

Figure 1 is a schematic view of a cartridge for an electrolysis cell,

Figure 2 is a schematic representation of an electrolytic cell formed from a stack of cassettes,

Figure 3A is an illustration of an opening in an electrolyte sheet formed by a bent section,

Figure 3B is an illustration of an opening in an electrolyte sheet formed by a recessed section,

Figure 3C is an illustration of an opening in an electrolyte sheet formed by a downward bent section,

Figure 3D is an illustration of an opening in an electrolyte sheet formed by a flange,

Figure 3E is an illustration of an opening in an electrolyte sheet formed by a curved section,

Fig. 3F is a diagram of openings in the electrolyte sheet, the openings being positioned with their length direction perpendicular to the centerline L of the electrolyte sheet,

Fig. 3G is a diagram of openings in the electrolyte sheet, the openings being positioned with their length direction parallel to the centerline L of the electrolyte sheet,

Fig. 3H is a diagram of openings in the electrolyte sheet, the openings being positioned with their lengthwise directions at an angle relative to the centerline L of the electrolyte sheet,

Fig. 3I is a schematic view of openings in an electrolyte sheet, with some of the openings positioned with their length direction perpendicular to the centerline L of the electrolyte sheet, and other openings positioned with their length direction parallel to the centerline L of the electrolyte sheet,

Fig. 3J is a diagram of openings in an electrolyte sheet, wherein the openings are positioned with their length directions at an angle relative to the centerline L of the electrolyte sheet, and in two opposite directions relative to each other,

Fig. 3K is a diagram of openings in an electrolyte sheet, where some of the openings are absent or blank,

Figure 4 is a schematic representation of the areas of the electrolyte plate and the cooling plate surrounding the respective electrolyte inlet and cooling fluid openings,

Figure 5A is a schematic representation of the area of the cooling inlet opening,

Fig. 5B is a diagram of the area of the cooling inlet opening, showing the opening formed in the tab,

Figure 5C is a graphical representation of the area of the catholyte gas outlet,

Figure 5D is a schematic representation of the anolyte gas outlet region,

Fig. 6 is a diagram of an end section of an electrolyte plate or cooling plate in the region of the electrolyte gas outlet, showing a barrier,

Fig. 7 is a diagram of the area of the anolyte gas outlet, showing an external gasket with beads,

Figures 8A and 8B are illustrations of the fixation of the membrane between two gasket portions,

Figure 9 is a schematic representation of a cooling unit of the cooling plate,

Figure 10 is a schematic representation of a cooling unit of two cooling plates contacted by a cross protrusion,

FIG. 11 is a side view of a cooling plate and electrolyte plate forming part of an electrolytic cell cartridge according to the invention, showing the contact posts, and

Fig. 12A and 12B illustrate possible geometrical relationships between the contact beams of the cooling plates.

Detailed Description

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

Fig. 1 shows the basic arrangement of a cassette 1 for an electrolysis cell according to the invention. The cartridge 1 is formed of two cooling plates 2 and two electrolyte plates 3a, 3c (anode plate 3a and cathode plate 3c, respectively).

Each of the cooling plates 2 is patterned, one side of one of the cooling plates 2 is connected to the anode plate 3a, and the other of the two cooling plates 2 is connected to the cathode plate 3c on one side. The two cooling plates 2 are connected to each other at their respective other sides. Thus, the two cooling plates 2 face each other on one side and on the other opposite side, each facing an electrolyte plate 3a, 3c in the form of an anode plate 3a and a cathode plate 3c, respectively.

Between two connected cooling plates 2a cooling path 5 is formed, which is adapted to the flow of cooling fluid from a cooling fluid inlet 7in to a cooling fluid outlet 7out.

Similarly, an anode electrolyte path 6a is formed between the anode plate 3a and one of the cooling plates 2 connected, and a cathode electrolyte path 6c is formed between the cathode plate 3c and one of the cooling plates 2 connected.

Electrolyte is fed into the anolyte path 6a via the anolyte fluid inlet 8in place of electrolyte that is converted to a gas (e.g., O ₂) that exits the anolyte path 6a via the anolyte gas outlet 8 out. Similarly, electrolyte is fed into catholyte path 6c via catholyte fluid inlet 9in, replacing electrolyte within catholyte path 6c that is converted to a gas (e.g., H ₂) that exits catholyte path 6c via catholyte gas outlet 9 out.

Fig. 1 shows how the electrolyte is positioned like a column within the electrolyte paths 6a, 6c, wherein the proportion of the electrolyte that is formed as a gas and leaves the respective electrolyte paths 6a, 6c via the respective electrolyte gas outlets 8out, 9out is replaced by new electrolyte that is fed into the electrolyte paths 6a, 6c via the respective electrolyte inlets 8in, 9 in.

The cassette 1 is adapted to a thin porous foil, also called membrane or film 4, to be positioned between the respective anode plate 3a and cathode plate 3c of two connected cassettes 1 (see also fig. 2).

The membrane 4 is electrically insulating or non-conductive to avoid electrical shorting between the electrolyte plates 3a, 3 c.

The membrane 4 may be attached at the outer surfaces of the electrolyte plates 3a, 3c, respectively, with respect to the anolyte pathway 6a and the catholyte pathway 6c, and may be fixed by a clip-on gasket, which will be described in more detail later.

An electrolyte solution (e.g., potassium hydroxide (KOH) or sodium hydroxide (NaOH)) is supplied to the anolyte pathway 6a via an anolyte fluid inlet 8in and to the catholyte pathway 6c via a catholyte fluid inlet 9 in.

Fig. 2 shows three cassettes 1 connected side by side with a membrane 4 pressed between them to separate the product gas and allow hydroxide ions (OH ") to be transported from the cathode plate 3c to the anode plate 3a, thereby generating oxygen in the anolyte pathway 6a and hydrogen in the catholyte pathway 6 c. Oxygen and hydrogen may then be collected at the anode gas outlet 8out and the cathode gas outlet 9out, respectively.

The electrolyte plates 3a, 3c are porous at least in the regions adapted to match the membrane 4, allowing diffusion of the product gas and transport of hydroxyl ions (OH-) through the membrane 4 and thus through the porous regions of the electrolyte plates 3a, 3 c.

Fig. 3A to 3J illustrate different embodiments of such apertures or electrolyte plate openings 11.

Fig. 3A shows an embodiment in which the electrolyte sheet openings 11 are formed as flaps 11a formed by cuts allowing the cut portions to form the flaps 11a that are bent outward. The surfaces of the electrolyte plates 3a, 3c opposite to the surfaces in the bending direction of the flaps 11a are substantially flat. The electrolyte plates 3a, 3c are positioned such that the flat surfaces face outwards with respect to the attached cooling plates 2 to form contact surfaces with the membrane 4.

The flaps 11a protrude towards the cooling plate 2 arranged adjacent to the electrolyte plates 3a, 3c, possibly without touching the cooling plate, and thus into the respective electrolyte paths 6a, 6 c. The flaps 11a may be positioned such that they "point" in the direction of the respective electrolyte gas outlets 8out, 9out, thereby ensuring a smooth flow of the incoming gas, such as hydrogen or oxygen.

Fig. 3B shows the same embodiment as fig. 3A with an outwardly bent flap 11a, but wherein a recess 12 is formed around the electrolyte sheet openings 11, which recess may extend in the length direction of the electrolyte sheets 3A, 3c and may cover a plurality of electrolyte sheet openings 11. A plurality of such recesses may be formed in each electrolyte plate 3a, 3c, and some or all of the electrolyte plate openings 11 may be located within such recesses 12.

The recess 12 is formed at an otherwise flat surface adapted to face the membrane 4, and is formed for the purpose of facilitating and guiding the flow of gases, such as hydrogen and oxygen, from the membrane 4 towards the opening 11.

Fig. 3C shows an embodiment in which the electrolyte sheet opening 11 is formed of two cutouts and the section between the two cutouts forms an extrapolated section 11b, which is, for example, "bridge", "arcuate", "arched", or the like. The extrapolation section 11b contacts the rest of the electrolyte plates 3a, 3c at two locations, forming opposite ends of the extrapolation section 11b along the direction defined by the two cutouts.

The extrapolation section 11b may be positioned such that at least one of the two openings 11 formed below the extrapolation section 11b points in the direction of the respective electrolyte gas outlet 8out, 9 out. This ensures a smooth flow of the incoming gas, such as hydrogen or oxygen.

The surface of the electrolyte plates 3a, 3c opposite to the surface in the bending direction of the push-out section 11b is substantially flat. The electrolyte plates 3a, 3c are positioned such that the flat surfaces face outwards with respect to the attached cooling plates 2 to form contact surfaces with the membrane 4.

The push-out section 11b will then face the respective cooling plate 2, preferably without contacting it, and thus extend into the respective electrolyte path 6a, 6 c.

Fig. 3D shows an embodiment in which the electrolyte plate opening 11 is formed by a push-down opening forming a flange 11 c. This is a simple construction in terms of production, and the substantially smooth transition of the flange 11c enables a smooth flow of gases, such as hydrogen and oxygen, into the respective electrolyte paths 6a, 6 c.

The flange 11c may be positioned such that the free ends of the flange 11c are directed in the direction of the respective electrolyte gas outlets 8out, 9 out. This ensures a smooth flow of the incoming gas, such as hydrogen or oxygen.

The surfaces of the electrolyte plates 3a, 3c opposite to the surfaces in the bending direction of the flange 11c are substantially flat. The electrolyte plates 3a, 3c are positioned such that the flat surfaces form the contact surfaces with the membrane 4.

The flange 11c will then project towards the respective cooling plate 2, preferably without contacting it, and thus extend into the respective electrolyte path 6a, 6 c.

Fig. 3E illustrates an embodiment in which the electrolyte sheet openings 11 are formed to be longer than they are wide and they may be oriented in at least two different directions 11d, 11E, 11F, as will be described below with reference to fig. 3F-3J.

In the illustrated embodiment, the opening 11 has a curved shape similar to a meat bone, and thus may be referred to as a "meat bone" shape. This means that the opening 11 has a concave section and a convex section. In the embodiment shown, both ends, which are arranged opposite to each other in the direction defined by the length of the opening 11, are concave as seen from the inside of the opening 11d, 11e, and there is a convex section at the middle portion as seen from the inside of the opening 11d, 11 e. Thus, the ends may form part of a circular shape or an oval shape. The width X of the male section is smaller than the width Y of the female section. The angle between the line (D) defined by the two points (a and B) and the horizontal axis (H) is between 5 ° and 20 °.

The openings 11d, 11e, 11f may be symmetrical, wherein the two halves mirror each other.

Fig. 3F shows an embodiment in which the opening 11d is positioned with its longitudinal direction perpendicular to the center line L passing along the longitudinal direction of the cartridge 1. The centre line L is also parallel to the general direction of the cooling fluid flowing from the cooling fluid inlet 7in to the cooling fluid outlet 7 out.

The center line L also corresponds to a line parallel to the longitudinal direction of the plates 2, 3a, 3 c.

Fig. 3G shows an embodiment in which the opening 11e is positioned with its length direction parallel to the center line L.

Fig. 3H illustrates an embodiment in which the opening 11f is positioned with its length direction at an angle (e.g., 45 degrees) with respect to the centerline.

Fig. 3I shows an embodiment in which some of the openings 11d are positioned with their length direction perpendicular to the center line L, and other openings 11e are positioned with their length direction parallel to the center line L. In the embodiment shown, they are positioned in an array-like structure, wherein each of the openings 11d, 11e of one orientation is surrounded by the openings 11e, 11d of the other orientation at all sides. The distance Z between the width X of the opening 11e and the lower end of the width X of the opening 11d is larger than the width X.

Fig. 3J is basically a combination of the embodiments of fig. 3H and 3I, wherein the openings 11f are angled in two opposite directions relative to each other and at an angle of about 45 degrees relative to the center line L.

Fig. 3K shows an embodiment similar to that of fig. 3F, but with some openings 11e either absent or blank. In other words, the electrolyte plates 3a, 3c have regions without the openings 11. This allows the contact posts 19 formed in the adjacent cooling plate 2 (see fig. 9 to 11) to contact the electrolyte plates 3a, 3c without blocking the openings 11. Alternatively, the contact posts 19 may be formed in the electrolyte plates 3a, 3c and protrude toward the adjacent cooling plate 2. As a further alternative, each contact stud 19 may be formed of two parts, one of which is formed in the electrolyte plate 3a, 3c and the other of which is formed in the adjacent cooling plate 2, and the two parts are in contact with each other to form the contact stud.

According to one embodiment, the width of the opening 11 at the central portion may be smaller than the upper width or diameter of the contact stud 19. This ensures that only a portion of the opening 11 is blocked by the contact posts 19 while maintaining contact with the electrolyte plates 3a, 3 c.

Embodiments with contact areas or smaller width diameters for the contact pillars 19 may also be suitable for any of the embodiments of fig. 3A-3J.

The active areas of the electrolyte plates 3a, 3c are formed between the electrolyte fluid inlets 8in, 9in and the gas outlets 8out, 9out, and are formed with openings 11, i.e. the active areas are porous. The active area is adapted to be aligned with the membrane 4.

Fig. 4 shows the areas of the electrolyte plates 3a, 3c and the cooling plate 2 around the respective electrolyte inlets 8in, 9in and the cooling fluid inlet 7in or cooling fluid outlet 7 out.

In the embodiment shown, the cooling fluid openings 7in, 7out as cooling fluid inlets 7in and/or cooling fluid outlets 7out are positioned at the corners of the plates 3a, 3c, 2, but they may be positioned elsewhere, such as at the center of the plates 3a, 3c, 2.

The cooling fluid flow direction in the cooling path 5 may be opposite to the electrolyte fluid flow direction in the respective electrolyte paths 6a, 6 c. Alternatively, the cooling fluid flow and the electrolyte fluid flow may be in the same direction. The cooling fluid inlet 7in and/or the cooling fluid outlet 7out may consist of one or more openings 7in, 7out, respectively (such as two openings 7in, 7out as shown).

This embodiment further shows an anolyte inlet 8in and a catholyte inlet 9in, respectively, between the two cooling openings 7in, 7out, such as seen with respect to a centre line L passing along the length of the cassette 1 and thus along the length of the plates 3a, 3c, 2, these inlets being in respective halves of the plates 3a, 3c, 2. For example, the electrolyte inlets 8in, 9in may be positioned at or near the center of their respective halves.

The electrolyte plates 3a, 3c and possibly the cooling plate 2 may be symmetrical with respect to the centre line L, the left half of the respective plate 3a, 3b, 2 being mirrored with the right half thereof.

The four plates 3a, 3c, 2 in the cartridge 1 are connected such that the cooling openings 7in, 7out are in fluid connection with the cooling path 5 but sealed from the electrolyte paths 6a, 6 c. The anolyte openings 8in, 8out are sealed from the cooling fluid path 5 and the catholyte openings 9in, 9out, respectively. In the same way, the catholyte openings 9in, 9out are sealed from the cooling fluid path 5 and the anolyte openings 8in, 8out, respectively. This is shown in more detail in fig. 5A-5D.

Fig. 5A to 5D show two cooling plates 2 between the anolyte plate 3a and the catholyte plate 3 c. The outer gasket 31 may be positioned at the outer circumference of the respective openings 7in, 7out, 8in, 8out, 9in, 9out to seal against the outside when connected to the other cartridge 1. When a plurality of cartridges 1 are stacked with their respective openings 7in, 7out, 8in, 8out, 9in, 9out aligned, these openings combine to form an opening volume through all four plates 3a, 3c, 2 of all cartridges 1.

Fig. 4 shows that the membrane 4 covers the active areas of the electrolyte plates 3a, 3 c. The active area is the section between the electrolyte fluid inlets 8in, 9in and the electrolyte gas outlets 8out, 9out and is where the electrolyte plate openings 11 are located. Surrounding the active area is a gasket 33' separating the electrolyte fluid in the active area from the electrolyte gas outlets 8out, 9 out.

Fig. 5A shows the area of the cooling inlet opening 7in, but the area of the cooling outlet opening 7out may be designed in a similar manner, and therefore the comments set forth below apply equally to the cooling outlet opening 7out. The two cooling plates 2 are in contact with each other at the edges and can be fixed to each other by, for example, welding or brazing 50.

A protrusion 55 may be formed at the circumference of the respective opening 7in, 70ut, 8in, 8out, 9in, 9out in the plate 3a, 3c, 2 to contact the adjacent plate 3a, 3c, 2, possibly a similar protrusion 55 formed in the adjacent plate 3a, 3c, 2. This stabilizes the area of the respective openings 7in, 7out, 8in, 8out, 9in, 9 out.

Referring also to fig. 5B, an opening 56 forming part of the cooling fluid inlet 7in is formed in the protrusion 55 so as to allow the respective fluid to enter the respective flow path 5, 6a, 6c.

In fig. 5A and 5B, the flow path is a cooling fluid path 5; in fig. 5C, the flow path is catholyte path 6C connected to catholyte gas outlet 9 out; whereas in fig. 5D, the flow path is the anolyte path 6a connected to the anolyte gas outlet 80 ut.

In fig. 5A, it is seen that the opening 56 is a recess 57 formed in the protrusion 55 in the cooling plate 2. The recess 57 ensures that the protrusion 55 formed in the cooling plate 2 does not contact the protrusion 55 formed in the adjacent electrolyte plates 3a, 3 c. Alternatively, the recess 57 may be formed in only one of the cooling plates 2, or the recess 57 may be formed in both of the cooling plates 2. The recesses 57 may be arranged facing each other if formed in both cooling plates 2, or they may be offset with respect to each other.

In fig. 5A, the recess 57 is formed only in two cooling plates 2, but it may alternatively be formed in one or both of the electrolyte plates 3c, 3a, or in one or both of the cooling plates 2 and in one or both of the cathode plate 3c and the anode plate 3 a.

In fig. 5C, the recess 57 is formed in only one of the cooling plates 2, i.e., in the cooling plate 2 facing the cathode plate 3C. In a similar manner, in fig. 5D, the recess 57 is formed only in the cooling plate 2 facing the anode plate 3 a. For both embodiments, recesses 57 may alternatively be formed in the cooling plate 2 protrusions 55 connected to the respective cathode plate 3c or anode plate 3a or both.

Fig. 6 shows an example cross section of one of the electrolyte paths 6a, 6c (i.e. the anolyte path 6a or the catholyte path 6 c) in the region around the electrolyte gas outlets 8out, 9 out. The cooling plate 2 can be formed in a similar manner in this region.

The electrolyte paths 6a, 6c may comprise sections extending from the edges 60 of the plates 2, 3a, 3c towards the centre line L and the respective electrolyte gas outlets 8out, 9 out.

One of the respective electrolyte gas outlets 8out, 90ut will be open to the respective electrolyte path 6a, 6c, while the other will be closed or sealed, e.g. by gaskets 33, in a similar manner to the cooling fluid openings 7in, 7out and optionally also by the circumferential edges of the plates 2, 3a, 3 c.

In order to partially separate the upper section electrolyte paths 6a, 6c around the electrolyte gas outlets 8out, 90ut from the lower section where the main gas generation occurs, an internal gas barrier 26 is provided, which blocks the gas flow back to the lower section of the active area.

The inner gas barrier 26 may comprise two halves that each decline or slope towards the centre line L, corresponding to declining or ramping towards the active area where the discharge 27 in the inner gas barrier 26 is located, allowing fluid, in particular fluid in liquid form, to drip back into the active area in this section due to gravity for further processing. This further prevents liquid from entering the gas outlets 8out, 9out and passing further in the system. This is an advantage, since the transfer of liquid may carry a risk of short circuits.

The cartridge 1 may be adapted to be positioned in a substantially vertical position with the gas outlets 8out, 9out at the top and the electrolyte fluid inlets 8in, 9in at the bottom. Undissolved liquids will then tend to fall downward due to gravity and will be collected by the internal gas barrier 26 because they are heavier than gas. The declining or sloping gas barrier 26 will direct the liquid toward the gas barrier discharge 27.

The lower internal gas barrier 26a may be positioned at the gas barrier discharge 27 immediately below the internal gas barrier discharge 27 on the side toward the active area.

The barrier 26, 26a, 27 may be formed in either the electrolyte plate 3a, 3c or the connected cooling plate 2, or in both, and will be adapted to contact the adjacent plate 2, 3a, 3c.

The section shown in fig. 6 may further comprise gas barriers 24, 25, for example formed as corrugations 24 and/or dimples 25, to flow the gas in a serpentine manner to further distribute the gas and liquid within the section.

The respective electrolyte gas outlet 8out, 9out is partly surrounded by the outlet plug 28, allowing only gas to leave the section via the opening 29 in the outlet plug 28 and move towards the electrolyte gas outlet 8out, 9 out. Facing the lower section, the outlet plug 28 may be provided with an outlet plug discharge 30 allowing possibly remaining fluid (mainly in liquid form) to drain back to the section.

Barriers such as gas barrier 24, internal gas barrier 26 and outlet plugs 28 may be formed by protrusions on plates 2, 3a, 3c facing each other and connected to block the passage of fluids and gases. Similarly, the indentations 25 may be formed by protrusions which may protrude to both sides and contact at opposite sides of the plates 2, 3a, 3c in order to form a support in this section.

Fig. 7 shows an embodiment of the outer gaskets 31 of the electrolyte gas outlets 8out, 9out, which outer gaskets are formed with "beads" 32 protruding into the electrolyte gas outlets 8out, 9out, wherein the beads 32 extend into both electrolyte gas outlets 8out, 9out when connected to the other cartridge 1. This prevents fluid from flowing into the gas channels, the electrolyte paths 6a, 6c and from leaking into the section between two connected cassettes 1.

Fig. 8A and 8B show an embodiment in which the membrane 4 is fixed between two connected cassettes 1 by clamping the membrane 4 between two gasket parts 13, 14, a first gasket part 13 (e.g. EPDM gasket) and a second gasket part 14 (e.g. Viton gasket).

The membrane 4 is clamped between the two electrolyte plates 3a, 3c of the connected cartridge 1 and placed in the grooves 13a' in the electrolyte plates 3a, 3c to hold them in place. To this end, the shim portions 13, 14 may be formed with protrusions 13', 14' adapted to be positioned within the grooves 13a '.

One shim portion (e.g., second shim portion 14) is formed with a locking portion 15 that extends through an aperture 4a in the membrane 4 and a shim aperture 16 of the other shim portion (e.g., first shim portion 13). The outer portion of the locking portion 15 has a larger diameter than the hole 4a of the membrane 4 and must therefore be forced through. This ensures that the membrane 4 and the shim portions 13, 14 are held together firmly and relative movement between them is substantially prevented. Accordingly, proper alignment of the various parts of the cartridge 1 relative to each other is ensured, and the risk of leakage is minimized.

Either one of the first gasket part 13 and/or the second gasket part 14 may be provided with a locking part 15 and a gasket opening 16, respectively.

The first pad section 13 or the second pad section 14, respectively, may be a pad 33' surrounding the active area.

In an embodiment, the gasket 33' is formed by a first gasket part 13 and a second gasket part 14, respectively, which are adapted to seal at the respective sides of the membrane 4. The respective first and second gasket parts 13, 14 may be formed of different materials adapted to the environment of each on both sides of the membrane 4, one of which may be made of inexpensive materials.

Such fixtures 4a, 13a ', 13', 14', 15, 16 may be positioned at regular intervals on the circumference of the membrane 4.

Fig. 9 shows a cooling plate 2 formed with cooling units 17 distributed at least in the areas contacting the electrolyte plates 3a, 3c adapted to be covered by the membrane 4, i.e. the active areas.

The purpose of the cooling unit 17 is to ensure an even distribution of the cooling fluid or cooling over the cooling plate 2 and correspondingly over the adjacent electrolyte plates 3a, 3 c. Fig. 9 shows only a few cooling units 17 (a total of eight cooling units 17) and correspondingly only a small part of the cooling plate 2. However, it should be understood that they may be distributed over the whole active area, or at least over a large part thereof, or even over the whole area of the cooling plate 2.

The cooling unit 17 may be formed with a pattern 18 adapted to contact a similar pattern 18 of connected adjacent cooling plates 2, thereby forming a cooling path 5 within the cooling unit 17. However, the pattern 18 does not contact the electrolyte plates 3a, 3c located on opposite sides, and thus the contact studs 19 are distributed over the cooling plate 2, such as within the cooling unit 17, as shown in fig. 9. The contact studs 19 formed in the respective cooling units 17 are directed towards the adjacent electrolyte plates 3a, 3c, rather than towards the adjacent cooling plates 2. Accordingly, the contact studs 19 of the respective adjacent cooling plates 2 do not point towards each other or protrude into the cooling unit 17 formed between two cooling plates 2.

The contact posts 19 are positioned to contact respective adjacent electrolyte plates 3a,3c in the areas between the electrolyte plate openings 11. This ensures a uniform distance between the support of the plates 2, 3a,3c and the cooling plate 2 and the electrolyte plates 3a,3c over the whole active area and is substantially independent of the pressure conditions within the cell box. The contact studs 19 may also form electrical contacts with the electrolyte plates 3a,3c, thereby supplying them with current/voltage.

The contact posts 19 may be fixedly attached to the respective electrolyte plates 3a, 3c, for example by welding or soldering. Alternatively, the contact posts 19 may be urged into contact with the respective electrolyte plates 3a, 3c simply by pressing the plates 2, 3a, 3c together.

In the embodiment shown in fig. 9, the contact studs 19 form part of the cooling plate 2 and are attached to or pushed into contact with the respective electrolyte plate 3a, 3 c. Alternatively, the contact studs 19 may form part of the electrolyte plates 3a, 3b and be attached to or pushed into contact with the cooling plate 2. As a further alternative, each contact stud 19 may comprise a portion forming part of the cooling plate 2 and a portion forming part of the electrolyte plates 3a, 3c, and the two portions may be attached to each other or pushed into contact with each other to form the contact stud 19.

Each cooling unit 17 is supplied with cooling fluid via a respective cooling unit inlet 21 from a cooling unit supply channel 20 extending between the cooling units 17. Each cooling unit supply passage 20 may be connected to a plurality of cooling units 17.

The cooling fluid (now having an elevated temperature) leaves the cooling unit 17 via a cooling unit outlet 23 and is fed to cooling unit return channels 22, wherein each cooling unit return channel 22 may be connected to a plurality of cooling units 17.

According to one embodiment, the area of the cooling plate 2 where the cooling unit 17 is formed may be adapted to be aligned with the active area of the electrolyte plates 3a, 3c, enabling control of the temperature of the gas generating process occurring in the electrolyte fluid in the electrolyte flow paths 6a, 6 c.

The cooling unit 17 is enclosed by a cooling unit wall 17a, wherein a respective cooling unit inlet 21 and cooling unit outlet 23 are formed in the cooling unit wall 17 a. The cooling unit walls 17a separate the individual cooling units 17 from each other and may be formed as protrusions in the two cooling plates 2 that are connected to form a flow barrier.

Fig. 10 shows the cooling units 17 of two cooling plates 2 positioned up and down. The corrugation patterns 18 of the respective cooling units 17 are positioned to cross each other and to be in contact at the crossing points defined by the patterns 18. This ensures that the flow of cooling fluid changes direction as it passes through the cooling fluid path 5 within each cooling unit 17, as it flows above and below the corrugations defined by the pattern 18.

The corrugation pattern 18 shown in fig. 9 and 10 is an example only and any other suitable pattern may be applied, such as V-shapes, dimples, etc.

The cooling unit inlets 21 and the cooling unit outlets 23 of the connected cooling units 17 of the respective two connected cooling plates 2 are positioned in alignment. In the embodiment shown, the inlet 21 is located at an upper portion of the cooling unit wall 17a, and the outlet 23 is located at a bottom portion, seen with respect to the flow direction of the cooling fluid flow.

Fig. 11 is a cross-sectional view of the cartridge 1 with the membrane 4 at the two electrolyte plates 3a, 3 c. A cooling flow path 5 is formed between the two cooling plates 2, and an anolyte path 6a and a catholyte path 6c are formed between the cooling plates 2 and the respective electrolyte plates 3a, 3 c.

The contact posts 19 are seen to be directed towards the electrolyte plates 3a, 3c so as to contact these electrolyte plates. Electrical contact is established with the electrolyte plates 3a, 3c via the contact studs 19, so that the cooling plate 2 itself serves as an electrical conductor.

The contact posts 19 may not be fixed to the electrolyte plates 3a, 3c and in an embodiment contact may be ensured by the pressure of the electrolyte solution in the electrolyte paths 6a, 6c being higher than the pressure of the cooling fluid 2 in the cooling fluid path 5.

Fig. 12A and 12B show the geometrical relationship between the contact studs 19 of the cooling plate 2. The thickness (t) of the cooling plate 2 is preferably in the range of 0.5mm to 0.7 mm. The contact posts 19 are placed at the corners of the rectangle. The horizontal distance between the contact studs 19 located at a first corner of the rectangle and the contact studs 19 located at a second corner of the rectangle is Z. X is half the length of the horizontal distance Z and is less than 160 (one hundred sixty) times the thickness t of the cooling plate 2 and is higher than 30 (thirty) times the thickness t of the cooling plate 2. The vertical distance between the contact stud 19 at the first corner of the rectangle and the contact stud 19 at the fourth corner of the rectangle is Y and is more than half X and less than twice X.

Fig. 12A shows an embodiment of the cooling plate 2, wherein the contact studs 19 are distributed at the corners of a rectangle and one contact stud 19 is placed at the intersection of the diagonals (D) of the rectangle.

Fig. 12B shows an embodiment of the cooling plate 2, wherein the contact studs 19 are distributed at the corners of a rectangle and two contact studs 19 are positioned at half the length of the horizontal distance Z (i.e. X).

Reference numerals

1-Box

2-Cooling plate

3 A-anolyte plate

3 C-catholyte plate

4-Film

4 A-Membrane pores

5-Cooling Path

6 A-anolyte pathway

6 C-catholyte path

7 In-cooling fluid inlet

7 Out-Cooling fluid Outlet

8 In-anolyte fluid inlet

8 Out-anolyte fluid gas outlet

9 In-catholyte fluid inlet

9 Out-catholyte fluid gas outlet

10-Clip type gasket

11-Electrolyte plate opening

11 A-cut section

11 B-push-down section

11 C-flange

11D, 11e, 11 f-electrolyte plate openings having a curved shape

12-Recess

13-First pad section

13' -Protruding part

13A' -groove

14-Second pad section

14' -Protruding part

15-Locking part

16-Spacer hole

17-Cooling unit

17 A-cooling unit wall

18-Pattern

19-Contact column

20-Cooling Unit supply channel

21-Cooling Unit Inlet

22-Cooling Unit return channel

23-Cooling Unit Outlet

24-Gas barrier

25-Dent

26-Internal gas barrier

26 A-lower internal gas barrier

Vents in a 27-inner gas barrier

28-Outlet plug

29-Openings in outlet plugs

30-Outlet plug discharge

31-Outer gasket

Bead of 32-gas outlet gasket

33-Pad

33' -Spacer surrounding active area

50-Welding/brazing

55-Protrusion

56-Opening

57-Recess

60-Plate edge

Claims

1. A cassette (1) for an electrolysis cell, the cassette (1) comprising two cooling plates (2) in contact with each other and forming a cooling flow path (5) between the two cooling plates, the cassette (1) further comprising two electrolyte plates (3 a,3 c), each electrolyte plate (3 a,3 c) contacting one of the cooling plates (2), wherein at least a portion of the cooling flow path (5) is divided into a plurality of cooling units (17), each cooling unit being connected to a cooling unit supply channel (20) via a cooling unit inlet (21) and to a cooling unit return channel (22) via a cooling unit outlet (23), forming a cooling flow path through each cooling unit (17) from the cooling unit inlet (21) to the cooling unit outlet (23), wherein the cooling units (17) are distributed over the cooling plates (2) in both directions.

2. The cartridge (1) according to claim 1, wherein the cartridge (1) further comprises at least one membrane (4) covering a region of at least one of the electrolyte plates (3 a,3 c), and wherein the cooling plates (2) are formed with cooling units (17) distributed at least in a region arranged in contact with a portion of the at least one electrolyte plate (3 a,3 c) covered by the membrane (4).

3. The cartridge (1) according to claim 1 or 2, wherein the cooling units (17) are formed with a pattern (18) adapted to contact a similar pattern (18) of connected adjacent cooling plates (2) so as to form cooling paths (5) within the cooling units (17).

4. A cassette (1) according to claim 3, wherein the pattern (18) is a corrugated pattern (18), and wherein the corrugated patterns of adjacent cooling plates (2) connected are positioned to cross each other and to be in contact at the crossing points.

5. The cartridge (1) according to claim 3 or 4, wherein the pattern (18) does not contact the electrolyte plate (3 a,3 c) located at the side of the cooling plate (2) opposite to the side contacting the other cooling plate (2).

6. The cartridge (1) according to any one of the preceding claims, wherein the contact studs (19) are distributed on the cooling plates (2) within the cooling units (17).

7. The cartridge (1) according to claim 6, wherein the contact studs (19) of each of the two cooling plates (2) face away from the other cooling plate (2) and are directed towards the respective electrolyte plate (3 a,3 c) positioned adjacent to these cooling plates (2).

8. The cartridge (1) according to claim 6 or 7, wherein the electrolyte plates (3 a,3 c) are formed with electrolyte plate openings (11) forming porous regions, and wherein the contact posts (19) are positioned to contact the electrolyte plates (3 a,3 c) in regions between the electrolyte plate openings (11).

9. The cartridge (1) according to any one of claims 6 to 8, wherein the contact posts (19) form electrical contact with the electrolyte plates (3 a,3 c) to supply current/voltage to the electrolyte plates.

10. The cartridge (1) according to any one of the preceding claims, wherein each cooling unit supply channel (20) is connected to a plurality of cooling units (17) via a respective cooling unit inlet (21) of the plurality.

11. The cartridge (1) according to any one of the preceding claims, wherein each cooling unit return channel (22) is connected to a plurality of cooling units (17) via their respective cooling unit outlets (23).

12. The cartridge (1) according to any one of the preceding claims, wherein each electrolyte plate (3 a,3 c) is formed with at least one electrolyte fluid inlet (8 in,9 in) and at least one gas outlet (8 out,9 out), and an active area is defined between the at least one electrolyte fluid inlet (8 in,9 in) and the at least one gas outlet (8 out,9 out), and wherein the areas of the cooling plates (2) where the cooling units (17) are formed are adapted to be aligned with the active areas of the electrolyte plates (3 a,3 c).

13. The cartridge (1) according to any one of the preceding claims, wherein the cooling units (17) are enclosed by a cooling unit wall (17 a), wherein the respective cooling unit inlet (21) and cooling unit outlet (23) are formed in the cooling unit wall (17 a).

14. The cartridge (1) according to claim 13, wherein the cooling unit walls (17 a) separate the individual cooling units (17).

15. Cassette (1) according to claim 13 or 14, wherein the cooling unit walls (17 a) are formed as protrusions in the two cooling plates (2) that are connected to form a flow barrier.