BE1031595B1 - ELECTROLYSER PACK - Google Patents

Abstract

Electrolyzer pack (1) comprising a chassis (2) extending longitudinally along a first axis (A), the chassis being pierced with at least one conduit (3) extending parallel to the first axis, the electrolyzer pack (1) comprising a first block (4) of electrolytic cells and a second block (4) of electrolytic cells, the two blocks (4) both being arranged in the chassis (2), at least the first block (4) being arranged in said conduit (3).

Description

[0001] TITLE OF THE INVENTION: Electrolyzer pack

[0002] DESCRIPTION

[0003] The invention also relates to an electrolyzer pack.

[0004] BACKGROUND OF THE INVENTION

[0005] The overall architecture of an electrolyser usually comprises a block of electrolytic cells, which are stacked in series from an electrical point of view and in parallel from a fluidic point of view, and sealing joints.

[0006] The purpose of each electrolytic cell is to promote the electrolysis of an electrolytic solution (alkaline water, pure water, unpurified water, salt, aqueous chloride solution, aqueous bromide solution, aqueous hydrochloric acid solution, etc.).

[0007] For example, the functionality of an electrolyser is to promote the reaction of production of dihydrogen (H.) and dioxygen (0) gas resulting from the dissociation of water after injecting a direct electric current into an alkaline solution, generally potassium hydroxide (KOH) or sodium hydroxide (NaOH).

[0008] Each electrolytic cell, considered as a mainly metallic and conductive part (but some parts of which may be non-metallic), is generally composed of two bipolar plates, framing two intercalators (better known by the English term "flow field material"), themselves framing two electrodes generally in the form of plates or grids or metal fabrics.

In the case of an alkaline electrolyser, said electrodes are generally made of nickel. The two electrodes (a cathode and an anode) are separated by a membrane (also called a diaphragm or porous separator in the case of the alkaline electrolyser), which ensures electrical insulation between the two electrodes, separation of gases as well as ionic conduction within the electrolytic cell.

[0009] The interlayer has two functionalities: i) to provide a low resistivity metallic path between each bipolar plate and the associated electrode and ii) to allow suitable circulation of the electrolytic solution for cooling the electrolyser and transporting the generated gases.

[0010] The name bipolar plate comes from the fact that as the electrolytic cells are all attached to each other, a bipolar N plate will have a potential:

[0011] higher relative to the downstream bipolar plate N+1, so that the bipolar plate N will play the role of anode within an electrolytic cell defined by the bipolar plates N and N+1;

[0012] lower compared to the upstream bipolar plate N-1, so that the bipolar plate N will play the role of cathode within an electrolytic cell defined by the bipolar plates N-1 and N.

[0013] Among the other metal parts, in addition to the bipolar plates, are listed the distribution plates (which allow the power supply and electrical distribution of the electrolytic cells) as well as the bottom plates (allowing the delimiting of all the electrolytic cells and ensuring the clamping of said electrolytic cells between them and their sealing).

[0014] Indeed, the electrolyser comprises two bottom plates located just before the first electrolytic cell and just after the last stacked electrolytic cell, in other words one bottom plate is located upstream of the block of electrolytic cells and the other bottom plate is placed downstream of the latter in order to physically delimit the two ends of said block of electrolytic cells.

[0015] Such an electrolyser, and in particular the electrolytic cell block, is unfortunately subject to buckling.

[0016] SUBJECT OF THE INVENTION

[0017] One aim of the invention is to propose a solution making it possible to limit the risk of deformation of a block of electrolytic cells.

[0018] SUMMARY OF THE INVENTION

[0019] For this purpose, according to the invention, there is provided an electrolyser pack comprising a chassis extending longitudinally along a first axis, the chassis being pierced with at least one conduit extending parallel to the first axis, the pack comprising a first block of electrolytic cells and a second block of electrolytic cells, the two blocks both being arranged in the chassis, at least the first block being arranged in said conduit.

[0020] Thus the electrolyser pack comprises a frame which supports the electrolytic cell blocks, which limits their deformations. The electrolyser pack is thus much less subject to deformations in general.

[0021] Furthermore, with the invention, it is possible to arrange several blocks of electrolytic cells inside the same chassis: the electrolyser pack can thus be of a shorter length than an electrolyser of the prior art while having the same efficiency thanks to this presence of several blocks of electrolytic cells. This reduction in length also contributes to reducing the risk of deformation of the electrolyser pack. In addition, the invention proves to be easier to install and handle. In particular, it is simpler to handle each of the blocks of electrolytic cells of lengths also shorter than a block of electrolytic cells of the prior art.

[0022] Advantageously, the invention is also easier to maintain: in fact, it is possible to carry out a maintenance operation on only part of the electrolytic cells of the electrolyser pack (by acting on only one of the blocks of electrolytic cells).

[0023] Optionally wherein the two blocks are arranged in the conduit.

[0024] Optionally, the conduit is a first conduit, the chassis being pierced with a second conduit.

[0025] Optionally, the conduits are distributed regularly in the chassis.

[0026] Optionally the first block is arranged in the first conduit and the second block is arranged in the second conduit.

[0027] Optionally, the first conduit and the second conduit extend parallel to each other.

[0028] Optionally, the two blocks are electrically connected in series.

[0029] Optionally, the two blocks are connected in parallel from a fluidic point of view.

[0030] Optionally the chassis is shaped into a solid of revolution.

[0031] Optionally the conduit has a circular cross section.

[0032] Optionally, the conduit extends coaxially to the first axis.

[0033] Optionally, the chassis includes at least one external reinforcement.

[0034] Optionally the pack includes between 5 and 20 blocks of electrolytic cells.

[0035] Optionally, each of the blocks has its own base plate and/or distribution plate.

[0036] Optionally, at least one fluid supply pipe for the electrolytic cell blocks and at least one fluid evacuation pipe for said blocks are provided in the chassis.

[0037] Other characteristics and advantages of the invention will emerge from reading the following description of particular and non-limiting embodiments of the invention.

[0038] BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Reference will be made to the accompanying drawings, among which:

[0040] [Fig. 1a] Figure 1a is a schematic cross-sectional view of an electrolyzer pack according to a first embodiment of the invention;

[0041] [Fig. 1b] Figure 1b is a schematic longitudinal sectional view of the electrolyzer pack illustrated in Figure 1a;

[0042] [Fig. 2] Figure 2 schematically represents the electrolyser pack shown in Figure 1a;

[0043] [Fig. 3] Figure 3 schematically represents a second possibility of electrical and fluidic connection of the electrolyser pack shown in Figure 1a;

[0044] [Fig. 4] Figure 4 is a schematic longitudinal sectional view of the electrolyzer pack according to a second embodiment of the invention.

[0045] DETAILED DESCRIPTION OF THE INVENTION

[0046] With reference to Figures 1a and 1b, an electrolyzer pack according to a first embodiment of the invention, generally designated 1, will now be described.

[0047] The electrolyser pack 1 extends longitudinally in a general direction A.

[0048] The electrolyser pack 1 comprises a chassis which also extends longitudinally in the general direction A.

[0049] The chassis is for example shaped into a solid of revolution and for example into a cylinder of revolution. The chassis is for example shaped into a right cylinder and for example a right circular cylinder.

[0050] The chassis is here shaped like a barrel 2.

[0051] Preferably, the barrel 2 comprises at least one reinforcement extending externally to the barrel 2 and for example at least one reinforcement extending longitudinally in the general direction A and/or at least one reinforcement extending circumferentially around the barrel 2. For example, the reinforcement is a spar or even an external collar or even a rib, etc.

[0052] Preferably, the barrel 2 comprises several reinforcements extending externally to the barrel 2 and distributed at regular intervals around and/or along the barrel.

[0053] Furthermore, the barrel 2 is pierced with at least one conduit 3. For example, the barrel 2 is pierced with a number X of conduits, X being between 1 and 14 and for example between 2 and 10 and for example between 4 and 7.

In this case, and in a non-limiting manner, barrel 2 has 7 conduits.

[0054] Preferably, the conduits 3 are arranged in the barrel 2 so as to be distributed in said barrel 2 in a homogeneous manner.

[0055] The different conduits 3 are here identical to each other.

[0056] Each of the conduits 3 here extends longitudinally parallel to the general direction

HAS.

[0057] The different conduits 3 thus extend parallel to each other.

[0058] Each of the conduits 3 optionally opens at a first longitudinal end on a first face of the barrel 2 (forming a first longitudinal end of the barrel 2) and at a second longitudinal end on a second face of the barrel 2 (forming a second longitudinal end of the barrel 2).

[0059] Each of the conduits 3 is for example shaped so as to have a circular cross section.

[0060] More precisely here, one of the conduits 3’ extends coaxially to the general direction A, i.e. at the center of the barrel 2 (conduit 3’ hereinafter called “central conduit”). Preferably, the other conduits 3 then extend all around the central conduit 3’. The other conduits 3 here jointly form a circle around the central conduit 3’. The other conduits 3 are circumferentially separated from each other by an equal distance between two successive conduits 3.

[0061] The electrolyser pack 1 also comprises several blocks 4 of electrolytic cells which each comprise at least two electrolytic cells which are mounted next to each other in a direction parallel to the general direction A (and coincident with said general direction

A in the case of block 4 arranged in the central duct 37).

[0062] The different blocks 4 of electrolytic cells are identical to each other.

[0063] For example, at both ends (along the general direction A) of each of the blocks 4 of electrolytic cells, the electrolyser pack 1 comprises two bottom plates. These bottom plates form supports between which the electrolytic cells of a block 4 considered are compressed so that said block 4 of electrolytic cells is sealed and so that a good quality electrical contact is created inside the electrolytic cells of said block 4. In addition, the bottom plates make it possible to withstand the forces generated by the internal pressure of the block 4 of electrolytic cells considered as well as the external forces to the block 4 of electrolytic cells considered necessary to ensure the compression of the block 4 of electrolytic cells considered.

[0064] For example, for each block 4 of electrolytic cells, the electrolyser pack 1 comprises a first distribution plate associated with the first bottom plate and a second distribution plate associated with the second bottom plate. The first distribution plate is arranged upstream of the block 4 of electrolytic cells and the second distribution plate is arranged downstream of said block 4 of electrolytic cells. The terms “upstream” and “downstream” are understood according to the traditional direction of flow of the current through the block 4 of electrolytic cells.

[0065] Preferably, for each block 4 of electrolytic cells, the electrolyser pack 1 comprises means for fixing the different electrolytic cells together by common clamping. Each block 4 of electrolytic cells may comprise its own fixing means or the same fixing means may be common to at least two different blocks of electrolytic cells.

[0066] For example, the fixing means comprise a plurality of tie rods. The fixing means also comprise nuts screwed onto the ends of the tie rods. Preferably, the fixing means also comprise means for prestressing the two bottom plates together and therefore the different electrolytic cells together (within each of the blocks 4 of electrolytic cells). Said prestressing means also make it possible to absorb the deformations and/or the variations in thickness of the elements constituting the block 4 of electrolytic cells considered. The prestressing means are received on the ends of the tie rods so as to be arranged, for a given end, between the closest bottom plate and the nuts arranged on the same end. For example, the fixing means comprise spring washers such as Belleville washers.

[0067] Furthermore, the different blocks 4 of electrolytic cells are arranged in the conduits 3 of the electrolyser pack 1. For example, the electrolyser pack 1 comprises a number Y of blocks 4 of electrolytic cells, Y being between 1 and 14 and for example between 2 and 10 and for example between 4 and 7. In the present case, the barrel 2 comprises 7 blocks 4 of electrolytic cells.

[0068] In the first embodiment, the electrolyser pack 1 comprises as many blocks 4 of electrolytic cells as the barrel 2 comprises conduits 3, 3’. In this way, each conduit 3, 3’ houses only a single block 4 of electrolytic cells and all the conduits 3, 3’ are equipped with a block 4 of electrolytic cells.

[0069] The different blocks 4 of electrolytic cells thus extend parallel to each other and to the general direction A.

[0070] The barrel 2 therefore makes it possible to support the different blocks 4 of electrolytic cells and limits their deformations. The barrel 2 makes it possible in particular to limit their buckling.

[0071] Within each block 4, the electrolytic cells are preferably mounted in parallel from a fluidic point of view and in series from an electrical point of view.

[0072] Between the different blocks 4 of electrolytic cells, different connection options are possible.

[0073] For example, and as illustrated in FIG. 2, the different blocks 4 of electrolytic cells can be mounted in parallel from an electrical point of view.

Alternatively, as illustrated in Figure 3, the different blocks 4 of electrolytic cells can be electrically connected in series.

[0074] Preferably, and in all cases, the electrolyser pack 1 (and therefore the different blocks and the different electrolytic cells) is here supplied with direct current.

[0075] Independently of the electrical connection of the electrolyser pack 1, the different blocks 4 of electrolytic cells can be mounted in parallel or in series from a fluidic point of view.

[0076] All options are possible.

[0077] Preferably, and as illustrated in FIG. 3, the blocks 4 of electrolytic cells will be mounted in parallel from a fluidic point of view.

[0078] This makes it possible to reduce the pressure losses inside the electrolyser pack 1.

[0079] Preferably, and as illustrated in Figure 3,

The 4 electrolytic cell blocks will be electrically connected in series.

[0080] This makes it possible to increase the voltage distributed in the different blocks 4 of electrolytic cells without increasing the floor area of the barrel 2.

This also helps to reduce shunt currents inside the electrolyser pack 1.

[0081] Whatever the options selected for the fluid connection and the electrical connection, the barrel 2 and/or the bottom plates and/or the distribution plates make it possible to ensure the electrical distribution within the electrolyser pack 1 as well as the circulation of the electrolytic solution inside said electrolyser pack 1 (solution more or less charged with gas depending on where one is positioned in the electrolyser pack 1).

[0082] For example, the barrel 2 is provided with one or more channels for the circulation of the electrolytic solution from one block 4 of electrolytic cells to another. Such channels are schematically represented in FIGS. 1a and 1b.

[0083] Preferably, the supply and evacuations of electrolytic solution are carried out only at the level of the barrel 2. At least one of the base plates may thus be devoid of a supply and/or evacuation orifice, unlike the base plates of the prior art.

[0084] Depending on the material of the barrel 2, the pipes and/or conduits 3 may be coated with an electrical insulator to prevent any interaction with the electrolytic solution.

[0085] For example, the barrel 2 is also provided with one or more channels for the circulation of an electrical supply from one block 4 of electrolytic cells to another. One of the distribution plates of one of the blocks 4 of electrolytic cells is connected to the positive terminal of the electrolyser pack 1 and one of the distribution plates of one of the blocks 4 of electrolytic cells is connected to the negative terminal of the electrolyser pack 1. The second of the two distribution plates then forms a negative terminal respectively.

[0086] Depending on the material of the barrel 2, the channels and/or conduits may be coated with an electrical insulator to prevent any interaction with the electrical supply.

[0087] With reference to Figure 4, a second embodiment will now be described.

[0088] This second embodiment is identical to the first embodiment except that at least one of the conduits 3 now houses at least two blocks 4 of electrolytic cells. For example, each of the conduits 3 now houses two blocks 4 of electrolytic cells. There are therefore twice as many blocks 4 of electrolytic cells as there are conduits 3 in the electrolyser pack 1 of the second embodiment.

[0089] Within each conduit 3, the two blocks 4 of electrolytic cells extend in the extension of one another parallel to the general direction A (or coaxially to the general direction A for the case of the central conduit) without necessarily touching.

[0090] As with the first embodiment, different connection options are possible.

[0091] For example, the different blocks 4 of electrolytic cells can be mounted in parallel from an electrical point of view. Alternatively, the different blocks 4 of electrolytic cells can be mounted in series from an electrical point of view.

[0092] Independently of the electrical connection of the electrolyser pack 1, the different blocks 4 of electrolytic cells can be mounted in parallel or in series from a fluidic point of view.

[0093] All options are possible. Preferably, the blocks 4 of electrolytic cells are mounted in parallel from a fluidic point of view and in series from an electrical point of view.

[0094] Apart from what has been stated above, everything said for the first embodiment is also applicable here.

[0095] Of course, the invention is not limited to the embodiments described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0096] In particular, the number of conduits 3, 3’ and/or blocks 4 of electrolytic cells may be different from what has been indicated. The number of blocks 4 of electrolytic cells arranged in at least one of the conduits 3, 3’ may be different from what has been indicated. For example, one of the conduits 3, 3’ may house at least two blocks 4 of electrolytic cells or at least three blocks 4 of electrolytic cells.

[0097] The electrolyser pack 1 may include other elements than what has been indicated and for example include a door mounted movably on at least one of the longitudinal ends of the chassis in order to be able to access the various conduits 3, 3' of the chassis when the door is open and protect the electrolyser pack 1 from the external environment when the door is closed.

[0098] Depending on the material of the chassis, it may include one or more means of electrical insulation, in particular at the longitudinal ends of the conduits 3, 3', in particular in the event of potential differences between them (such as, for example, one or more layers of electrically insulating materials).

[0099] The chassis may be in one or more parts and/or in one or more materials. The chassis may thus be made of metal, composite, plastic, etc.

[0100] Although here at least one of the conduits opens at each of the longitudinal ends, said conduit may open at only one of its longitudinal ends or may not open at any of its longitudinal ends (the block of electrolytic cells being for example arranged in a radial direction and not an axial direction in said conduit).

[0101] Although here each block of electrolytic cells has its own bottom plates, the electrolyser pack may have at least one bottom plate common to at least two blocks of electrolytic cells. For example, the electrolyser pack may have only two bottom plates,

each bottom plate being common to all the blocks of electrolytic cells of said pack (one being associated with a first of the longitudinal ends of the pack and the other with the second of the longitudinal ends of the pack).

[0102] Although here each block of electrolytic cells comprises its own distribution plates, the electrolyser pack may comprise at least one distribution plate common to at least two blocks of electrolytic cells. For example, the electrolyser pack may comprise only two distribution plates, each distribution plate being common to all the blocks of electrolytic cells of said pack (one being associated with a first of the longitudinal ends of the pack and the other with the second of the longitudinal ends of the pack).

[0103] Although here the supply and evacuations of electrolytic solution are carried out only at the chassis level, the supply and evacuations of electrolytic solution may be carried out in part or in full by one or more bottom plates of the electrolyser pack.

[0104] The chassis may not be shaped like a barrel. For example, the chassis may be shaped externally like a rectangular parallelepiped and not like a cylinder of revolution as indicated above.

Claims (15)

1. Electrolyzer pack (1) comprising a chassis (2) extending longitudinally along a first axis (A), the chassis (2) being pierced with at least one conduit (3) extending parallel to the first axis, the electrolyzer pack (1) comprising a first block (4) of electrolytic cells and a second block (4) of electrolytic cells, the two blocks (4) both being arranged in the chassis (2), at least the first block (4) being arranged in said conduit (3). 2. Electrolyzer pack (1) according to claim 1, in which the two blocks (4) are arranged in the conduit (3). 3. Electrolyser pack (1) according to claim 1 or claim 2, in which the conduit (3) is a first conduit (3), the chassis (2) being pierced with a second conduit (3). 4. Electrolyzer pack (1) according to claim 3, in which the conduits (3) are distributed regularly in the chassis (2). 5. Electrolyzer pack (1) according to one of claims 1 to 4, in which the first block (4) is arranged in the first conduit (3) and the second block (4) is arranged in the second conduit (3). 6. Electrolyzer pack (1) according to one of claims 3 to 5, in which the first conduit (3) and the second conduit (3) extend parallel to each other. 7. Electrolyser pack (1) according to one of the preceding claims, in which the two blocks (4) are electrically connected in series. 8. Electrolyzer pack (1) according to one of the preceding claims, in which the two blocks (4) are connected in parallel from a fluidic point of view. 9. Electrolyzer pack (1) according to one of the preceding claims, in which the chassis (2) is shaped as a solid of revolution. 10. Electrolyzer pack (1) according to one of the preceding claims, in which the conduit (3) has a circular cross section. 11. Electrolyzer pack (1) according to one of the preceding claims, in which the conduit (3) extends coaxially with the first axis. 12. Electrolyzer pack (1) according to one of the preceding claims, in which the chassis (2) comprises at least one external reinforcement. 13. Electrolyzer pack (1) according to one of the preceding claims, comprising between 5 and 20 blocks (4) of electrolytic cells. 14. Electrolyser pack (1) according to one of the preceding claims, in which each of the blocks (3) comprises a base plate and/or a distribution plate specific to it. 15. Electrolyzer pack (1) according to one of the preceding claims, in which at least one fluid supply pipe for the electrolytic cell blocks and at least one fluid evacuation pipe for said blocks are provided in the chassis (2).