Modular assembly for a solid oxide electrolysis system

Abstract

The invention relates to a modular assembly for a solid oxide electrolysis system for producing hydrogen. The assembly comprises at least one module (1) comprising at least one stack (2) of solid oxide plates positioned in a heat chamber (3), pipes for supplying fluids into the stack (2), pipes for discharging fluids from the stack (2), and at least one fluid-heating device allowing the fluid to reach a temperature that is compatible with the operation of the stack (2). The module (1) comprises a first removable part (10) provided with first connectors (4) for fluid pipes, which part comprises the stack (2) of solid oxide plates positioned in the heat chamber (3), and a second fixed part (11) provided with second connectors (5) capable of being connected to and disconnected from the first connectors (4). The second fixed part (11) comprises a distribution network (13) comprising the fluid supply pipes (14) and fluid discharge pipes (15).

Description

MODULAR PACKAGE FOR SOLID OXIDE ELECTROLYSIS SYSTEM

[0001] The present invention relates to a modular assembly for implementation in a solid oxide electrolysis system for the production of hydrogen.

[0002] The assembly according to the invention offers a solution which adapts to different hydrogen production capacities and which solves the problems linked in particular to the maintenance of current systems, to the transport of such systems, or even to their repair, once the systems are installed.

[0003] The invention finds particular application in the manufacture of equipment used at high temperature. State of the art

[0004] Solid oxide electrolyzer systems are used to produce hydrogen and oxygen from a stream including water vapor. They also produce carbon monoxide from carbon dioxide.

[0005] To do this, they comprise cells comprising stacks of solid oxide plates, in particular ceramics (also called "stacks"), which form the electrodes of an electrolyser and which ensure the production of dihydrogen and / or carbon monoxide at high temperature (between approximately 500°C and 850°C).

[0006] The larger the surface area of ​​the electrodes, the greater the production of hydrogen or carbon monoxide.

[0007] Thus, to produce industrial quantities of dihydrogen or carbon monoxide, the systems must have large surfaces of solid oxide plates and therefore many cells.

[0008] The disadvantage of large systems lies in their maintenance and manufacturing: they are manufactured on site or they require significant means of transport to bring such systems to the site.

[0009] An aim of the present invention is to remedy at least one of the drawbacks of the state of the art by proposing a modular assembly for a solid oxide electrolysis system, the maintenance of which is rapid and the manufacture or transport of which requires standard means of transport (for example by standard-sized truck) and which makes it possible to produce systems of all sizes depending on the quantity of gas to be produced from the site that it is desired to exploit.

[0010] To this end, the invention relates to a modular assembly for a solid oxide electrolysis system for the production of hydrogen, said system comprising at least one module comprising at least one stack of solid oxide plates (also called a stack in English) positioned in a hot enclosure, fluid supply lines into said at least one stack, fluid discharge lines from said at least one stack, and at least one fluid heating device allowing the fluid to reach a temperature compatible with the operation of said at least one stack.

[0011] The assembly according to the invention is remarkable in that said at least one module comprises two parts among which:- a first removable part, equipped with first fluid pipe connectors, which comprises said at least one stack of solid oxide plates positioned in said hot enclosure, and- a second fixed part, forming a docking station for said first removable part, said second fixed part being equipped with second connectors capable of being assembled with and disassembled from said first connectors of said first removable part, said second fixed part further comprising a fluid distribution network comprising said fluid supply pipes and said fluid discharge pipes, each second connector of said second fixed part being connected to a fluid pipe among said fluid supply or discharge pipes, said assembly further comprising a control unit,controlling in particular the supply and evacuation of fluids circulating in the fluid pipes, as well as the operation of said fluid heater, and a power electronics module.,

[0012] Thus designed, the invention offers a solution that facilitates the testing, maintenance and repair of the installed system. Indeed, the removable part of the module(s) that comprise the modular assembly can be removed and replaced by another in the event of malfunction,

[0013] In addition, thanks to the simplified interfaces (first and second connectors capable of being assembled and disassembled), the operation of replacing a module is limited to disconnecting and reconnecting simple fluid connections (generally flanges) and standard electrical connectors.

[0014] The ability to easily connect and disconnect these basic elements also simplifies the deployment of large systems.

[0015] Connecting modules to stacks can be done once on site, meaning there is no need to ship the system with modules and stacks already connected.

[0016] This flexibility helps reduce the footprint of the shipped equipment, and the system is shipped disassembled and can be easily assembled on site.

[0017] Advantageously, the modular system according to the invention has one or more of the following characteristics, taken individually or in any technically possible combination:

[0018] Advantageously, said fixed part of the module (or docking station) comprises at least one valve for admitting a fluid from a supply line to said removable part of said at least one module and in that the control unit is capable of controlling an open position of said valve, a closed position of said valve and intermediate positions between said open position and said closed position, in order to authorize, prevent or regulate the flow of fluid admitted into said removable part of said at least one module from the fluid supply line. This embodiment offers the advantage of allowing the isolation of modules which no longer function, pending their replacement during future maintenance.

[0019] Furthermore, said fixed part of the module (or docking station) preferably comprises at least one heat exchanger, providing a heat recovery function between the fluids discharged by the discharge pipes and the fluids supplied by the supply pipes. This embodiment makes it possible to recover the heat emitted by the outlet gases leaving the module to heat the inlet gases coming from the gas distribution network.

[0020] Advantageously, said fixed part of the module (or docking station) comprises a cooling system making it possible to reduce the temperature of the evacuated fluids, said cooling system being positioned downstream of said heat exchanger: such a cooling system avoids the use of bulky and expensive high-temperature isolation valves.

[0021] According to an advantageous embodiment, said fixed part of the module (or docking station) comprises a thermocouple, capable of measuring a fluid temperature in said fluid supply pipe and in said fluid discharge pipe.

[0022] Furthermore, said fixed part of the module (or docking station) comprises a fluid flow regulator in said supply line and / or in said discharge line.

[0023] The hot chamber includes an electric chamber heating system capable of ensuring the temperature rise and maintenance at the operating temperature of the hot chamber and the solid oxide stack(s) which will be operated there.

[0024] Furthermore, the hot enclosure comprises at least one gas heating device, preferably an electric heating system.

[0025] Advantageously, said gas heater is positioned in said fixed docking station of said at least one module.

[0026] According to an alternative embodiment, said gas heater is positioned in the removable part of said at least one module.

[0027] Advantageously, the removable part of said at least one module comprises an external electrical interface, comprising electrical connectors.

[0028] According to an advantageous embodiment, said electrical interface comprises:- a direct current (DC) line connection for supplying current to the battery(ies),- voltage cell measuring wires,- thermocouples (“for measuring the temperature of the chimney or the temperature of the gas, for example at the inlet and outlet of the chimney(s)”), and- possibly at least one electrical connection for supplying current to at least one heating device when said hot enclosure comprises a heating device.

[0029] According to an advantageous embodiment, the removable part of said at least one module comprises at least one device for holding said at least one stack in position in said hot enclosure, possibly comprising a compression load.

[0030] Furthermore, said removable part of said at least one module comprises an external interface, capable of executing an interrogation or measurement system.

[0031] Furthermore, said removable part of said at least one module comprises at least one thermal insulation wall.

[0032] According to a preferred embodiment, at least one thermal insulation wall extends all around the hot enclosure or only on the top of said hot enclosure, on the bottom of said hot enclosure and possibly on a front part and / or on a rear part of said hot enclosure. Thus, the hot enclosure can be partially or entirely insulated, depending on the positioning configuration of the removable parts of the modules relative to the fixed part and relative to each other in an assembly which would comprise several modules positioned next to each other.

[0033] The invention also relates to an assembly which comprises several modules, each module comprising a first removable part, equipped with first fluid conduit connectors, which comprises said at least one stack of solid oxide plates positioned in said hot enclosure, said fixed part of the modules forming a common docking station for all the removable parts of the modules, said docking station being equipped with second connectors which can be assembled with and disassembled from said first connectors of each accommodated removable part, said fluid distribution network comprising said fluid supply conduits and said fluid discharge conduits being common to all the modules.

[0034] According to an advantageous embodiment, it may be provided that said docking station comprises thermal insulation walls which cover a set of side walls of removable parts of modules accommodated in said docking station: this makes it possible to manufacture removable parts of modules which are partially insulated, making it possible to produce a less bulky assembly on the ground, and lighter and less expensive removable parts, as will be understood subsequently during the presentation of an embodiment.

[0035] Finally, the assembly may include removable inclusion devices positioned in gaps between two removable parts of adjacent modules. Brief description of the figures

[0036] The invention will be better understood on reading the description which follows, given solely as a non-limiting example and made with reference to the appended drawings in which:

[0037] : is a first schematic representation of a modular assembly in accordance with the invention, seen from above,

[0038] : is a schematic representation of two stack modules that comprise the assembly shown in, illustrating the connection of the stack modules to the supply and discharge pipes of the stack modules,

[0039] : is a left side view of the assembly shown in, and

[0040] : this is a front view of the assembly shown in.

[0041] It is understood that the embodiments which will be described below are in no way limiting. In particular, it is possible to imagine variants of the invention comprising only a selection of characteristics described below isolated from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention compared to the state of the prior art. This selection includes at least one preferably functional characteristic without structural details, or with only part of the structural details if it is this part which is only sufficient to confer a technical advantage or to differentiate the invention compared to the state of the prior art.

[0042] In particular, all the variants and embodiments described can be combined with each other if there is no technical obstacle to this combination.

[0043] In the figures and in the rest of the description, the elements common to several figures retain the same reference. Detailed description

[0044] Illustrates an example of a modular assembly in accordance with the invention, a solid oxide electrolysis system for the production of hydrogen.

[0045] The assembly comprises eight modules 1, each comprising two stacks 2 of solid oxide plates, positioned in a hot enclosure 3.

[0046] Each of the modules 1 comprises a first removable part 10, equipped with first connectors 4 for fluid lines.

[0047] As can be seen in Figures 1 and 2, the removable part of the modules comprises the stacks of solid oxide plates 2 positioned in the hot enclosure 3.

[0048] A single stack of plates 2 is illustrated, in order to facilitate reading of the figure. However, it should be understood that the removable part 10 could comprise a different number of stacks of plates 2 without departing from the scope of the invention.

[0049] According to the invention, each of the modules 1 also comprises a fixed part 11 which forms a docking station for the first removable part 10 of each module 1.

[0050] More particularly, in this context of this example, the docking station forming said fixed part 11 of each module can be common for all the removable parts 10 of modules.

[0051] As can be seen in, said docking station 11 is equipped with second connectors 5, capable of being assembled with the first connectors 4 and of being disassembled from the latter.

[0052] It can be seen in particular in Figures 1 and 2 that each fixed docking station 11 comprises a network 13 of fluid distribution pipes.

[0053] More precisely, the docking station 11 is connected to the network 13 of pipes which comprises a set of fluid supply pipes 14 and a set of fluid discharge pipes 15.

[0054] It is also noted that each second connector 5 of said docking station 11 is indirectly connected to a fluid pipe 14 or 15.

[0055] Indeed, it can be seen that the second connectors 5 are connected to the pipes 14 or 15 by means of devices 16 whose usefulness will be explained later.

[0056] It should be understood that the second connectors 5 could be connected directly to the pipes 14 and 15, according to another embodiment not described and illustrated, without however departing from the scope of the invention.

[0057] As can be seen in, and in accordance with the invention, the assembly according to the invention further comprises a control unit 7, controlling in particular the supply and evacuation of the fluids circulating in the fluid conduits 14 and 15, as well as the operation of the devices 16.

[0058] The assembly also includes a power electronics module 17 which provides the electrical power supply to the modules and the control unit, to ensure their operation.

[0059] The devices 16 are fluid heating devices: in fact, for the stacks of plates to be able to perform their role and allow the production of dihydrogen, the fluid must be brought to a sufficiently high temperature.

[0060] Thus, the fluid heating devices 16 allow the fluid brought by the supply lines 14 to reach a temperature compatible with the operation of the stack of plates 2. They are thus positioned in the fixed parts of the modules 1, that is to say in the fixed docking stations 11. The, in its left part, illustrates this first configuration with the gas heaters installed in the fixed part. The in the right part illustrates the alternative configuration with the gas heaters installed in the mobile part 10.

[0061] Of course, and as indicated previously, if the second connectors 5 were directly connected to the conduits 14 and 15, it could be provided to install the heating devices 16 in the removable parts 10 of the modules 1, without departing from the scope of the invention: this embodiment would constitute an alternative implementation of the invention. The heating devices could, for example, be positioned in or near the hot enclosures 3 of the removable parts 10 of the modules 1.

[0062] On the, the control unit 7 comprises two main control modules; a module 6 for controlling the fluids and a module 8 for operating devices which ensure the separation of the fluids and their recycling, in particular. It should be understood that the treatment and separation of the fluids part could be carried out elsewhere, in another downstream device.

[0063] Fluid Control Module 6 includes, in particular:

[0064] - a system 60 for controlling the valves controlling the admission of steam flow and the evacuation of dihydrogen produced,

[0065] – a control system 61 of valves controlling the circulation of nitrogen (to control the temperature of the fluids evacuated by cooling) and dihydrogen,

[0066] – a control system 62 for the pressures of circulating fluids,

[0067] – a system 63 for controlling a main air exhaust flow, and

[0068] – a system 64 for controlling a secondary air exhaust flow.

[0069] The control module 8 comprises a set 80 of devices dedicated to flow separation and cooling: a device 81 dedicated to the separation of dihydrogen and water, an air-cooling device 82 and a “chiller” device 83. The device 82 uses ambient air to cool a fluid that is at a higher temperature. The chiller device 83 is another cooling device that comprises a cold unit, i.e. one that will cool a heat transfer fluid to a temperature below ambient temperature, which will be able to cool the effluents of the system to temperatures below ambient temperature. This chiller is necessary in particular for the separation of hydrogen from the residual water vapor at the electrolyzer outlet. This separation is achieved by the condensation of the water vapor, which requires temperatures below ambient temperature.

[0070] It also includes a main blower 84, a secondary blower 85, an automation cabinet 86, a hydrogen outlet booster 87, a recycle pump and nitrogen and dihydrogen circulation control valves 88 linked to the blower and a recycle pump and hydrogen flow control valves 89.

[0071] Figures 2, 3 and 4 illustrate in more detail said docking station of the assembly according to the invention:

[0072] It comprises, as indicated previously, valves 9 for admitting a fluid from the supply lines 14. As seen previously, it is the control unit 7 which controls the opening or closing of the valves and the intermediate positions in order to authorize, prevent or regulate the flow of fluid admitted into said removable part of said at least one module from the fluid supply line.

[0073] The control unit 7 associated with the valves 9 can thus isolate faulty modules while allowing the other modules to remain in operation, until the next maintenance.

[0074] The fluid circulating in the supply pipes 14 is a flow of water vapor and carbon dioxide and / or carbon monoxide.

[0075] Other valves are also provided: valves 90 and 91 make it possible to regulate and, respectively, to authorize or prohibit the entry of air and the exit of air into the docking station 11 from the network 13 of pipes.

[0076] The pipe network 13 further comprises a compressed air system 12 which ensures the control of the valves 9, 90, 91 (in the case where they are pneumatically controlled, knowing that they can also be electric) as well as a pipe system 17 which ensures the operation of a valve 92 ensuring the circulation of air in the hot enclosure 3. An air evacuation duct 93 is also provided from the hot enclosures of the moving parts of the modules.

[0077] The docking station 11 of the modules also includes a system of heat exchangers (reference 20 on the) providing a heat recovery function between the fluids evacuated by the evacuation pipes and the fluids supplied by the supply pipes, as well as a cooling system making it possible to reduce the temperature of the evacuated fluids, said cooling system being positioned downstream of said heat exchanger, between the exchangers 20 and the valves 90, 91, 92.

[0078] The docking station may also include a thermocouple capable of measuring a fluid temperature in said fluid supply line and in said fluid discharge line.

[0079] Illustrates an example of an assembly in accordance with the invention where the removable parts 10 of the modules are produced in two different ways: on the left part of the figure, the removable parts 10 (the removable characteristic being illustrated schematically by an arrow F) comprise a hot enclosure 3 which comprises at least one stack 2 of plates (stacks) connected to a first connector 4.

[0080] The fixed docking station 11 of this module 1 on the left comprises a heating device 16, a heat recovery system 20, all of the control valves 90 to 92 connected to the network pipes 13.

[0081] The set of valves 90 to 92 forms a block ensuring the power supply or isolation of the module if the module is not functioning correctly.

[0082] The removable part 10 of the module 1 of the right part of the is different from that of the left part: it comprises the hot enclosure 3, at least one stack 2 and also a heating device 16 (which is thus located in the removable part 10 rather than in the fixed part 11 of the module).

[0083] The heating device may be an electric heater.

[0084] It is also noted that the removable parts 10 of the modules each comprise an external electrical interface 18, which comprises electrical connectors. It should be understood that the external position of the interface 18 is optional: it could be installed between the removable part and the fixed part directly of the module.

[0085] The electrical interface comprises:- a DC line connection for supplying power to the battery(ies),- voltage cell measuring leads,- thermocouples (“for measuring the stack temperature or the gas temperature, for example at the inlet and outlet of the stack(s)”), and- optionally at least one electrical connection for supplying power to at least one heating device when said hot enclosure comprises a heating device.

[0086] The electrical interface can also allow an interrogation or measurement system to be executed, to check the correct functioning of the elements internal to the removable parts 10.

[0087] The removable parts 10 of the modules also include devices 19 which ensure that the stack(s) 2 are held in position in the hot enclosures 3.

[0088] These devices 19 are shown in more detail on the: they can include a compression load, a spring working in compression or any other mechanism allowing a controlled force to be applied (pneumatic piston, electromechanical cylinder, etc.)

[0089] Lamontre also shows an embodiment making it possible to insulate the removable parts 10 so as to maintain the temperature of the hot enclosures 3 which they comprise at a lower cost.

[0090] At the top of the, a removable module part 10 is illustrated in front view (left) and side view (right).

[0091] We thus observe that the removable part 10 has side walls of unequal thicknesses, constituting thermal insulation walls 21 among which: a wall covering the top of the hot enclosure, an insulation wall on the front face and another on the rear face. The enclosure is also thermally insulated from below, thanks to a thicker base crossed by the heating device 16 and the pipes which run from the hot enclosure to the first connectors.

[0092] The hot enclosure 3 includes a thin layer of thermal insulation 22 on its side walls.

[0093] It is noted in particular that the enclosure 3 comprises, on either side of the stack 2, additional heating elements 23.

[0094] In the lower part of the, a part of the docking station 11 is illustrated, common to all the removable parts 10 of the modules.

[0095] It is observed that the docking station comprises a docking tray where the removable parts 10 are positioned next to each other, the bottom comprising peripheral thermal insulation walls 24 which cover a set of side walls of removable parts 10. The hot enclosures 3 of the modules are thus thermally insulated to best maintain their internal operating temperature.

[0096] To perfect the thermal insulation of the assembly, provision is made to have inclusion devices 25, which are removable: they are positioned in gaps between two removable parts 10 of adjacent modules.

[0097] Thus realized, the assembly can easily be assembled on site and the removable parts 10 which do not function adequately can be isolated from the other functional parts, without having to stop the entire assembly.

[0098] To replace one removable part with another, it is necessary to stop the operation of the assembly, remove the inclusion devices 25, disconnect the defective removable part 10 and replace it with another functional one.

[0099] It is understood from the above how the invention makes it possible to achieve the technical objectives of ease of installation and maintenance.

[0100] Of course, the invention is not limited to the examples which have just been described.

Claims

Modular assembly for a solid oxide electrolysis system for the production of hydrogen, said system comprising at least one module (1) comprising at least one stack (2) of solid oxide plates positioned in a hot enclosure (3), fluid supply lines in said at least one stack (2), fluid discharge lines from said at least one stack (2), and at least one fluid heating device allowing the fluid to reach a temperature compatible with the operation of said at least one stack (2), characterized in that said at least one module (1) comprises two parts among which: - a first removable part (10), equipped with first connectors (4) of fluid lines, which comprises said at least one stack (2) of solid oxide plates positioned in said hot enclosure (3), and - a second fixed part (11), forming a docking station for said first removable part (10),said second fixed part (11) being equipped with second connectors (5) capable of being assembled with and disassembled from said first connectors (4) of said first removable part (10), said second fixed part (11) further comprising a fluid distribution network (13) comprising said fluid supply lines (14) and said fluid discharge lines (15), each second connector (5) of said second fixed part (11) being connected to a fluid line among said fluid supply lines (14) or discharge lines (15), said assembly further comprising a control unit (7), controlling in particular the supply and discharge of the fluids circulating in the fluid lines (14, 15), as well as the operation of said fluid heater, and a power electronics module (17)., Modular assembly according to claim 1, characterized in that said second fixed part (11) comprises at least one admission valve (9) for a fluid from a supply pipe (14) to said removable part (10) of said at least one module (1) and in that the control unit (7) is capable of controlling an open position of said at least one valve (9), a closed position of said at least one valve (9) and intermediate positions between said open position and said closed position, in order to authorize, prevent or regulate the flow of fluid admitted into said removable part (10) of said at least one module (1) from the fluid supply pipe (14). Modular assembly according to claim 1 or 2, characterized in that said second fixed part (11) of said at least one module (1) comprises at least one heat exchanger (20) providing a heat recovery function between the fluids discharged by the discharge pipes (15) and the fluids supplied by the supply pipes (14). Modular assembly according to claim 3, characterized in that said second fixed part (11) of said at least one module (1) comprises a cooling system making it possible to reduce the temperature of the evacuated fluids, said cooling system being positioned downstream of said heat exchanger 20. Modular assembly according to any one of the preceding claims, characterized in that said second fixed part (11) of said at least one module (1) comprises a thermocouple capable of measuring a fluid temperature in said fluid supply pipe (14) and in said fluid discharge pipe (15). Modular assembly according to any one of the preceding claims, characterized in that said second fixed part (11) of said at least one module (1) comprises a fluid flow regulator in said supply pipe (14) and / or in said discharge pipe (15). Modular assembly according to any one of the preceding claims, characterized in that the hot enclosure (3) of said at least one module (1) comprises at least one heating device (23), preferably an electric radiator. Modular assembly according to any one of the preceding claims, characterized in that said fluid heater (16) is positioned in said second fixed part (11) of said at least one module (1). Modular assembly according to any one of claims 1 to 7, characterized in that said fluid heater (16) is positioned in said removable part (10) of said at least one module (1). Modular assembly according to any one of the preceding claims, characterized in that the removable part (10) of said at least one module (1) comprises an electrical interface (18), possibly external, comprising electrical connectors. Modular assembly according to claim 10, characterized in that said electrical interface (18) comprises:- a direct current line connection for supplying current to the battery(ies),- voltage cell measuring wires,- thermocouples, and- possibly at least one electrical connection for supplying current to at least one heating device when said hot enclosure comprises a heating device. Modular assembly according to claim 10, characterized in that said removable part (10) of said at least one module (1) comprises at least one device (19) for holding said at least one stack (2) in position in said hot enclosure (3), said device (19) for holding in position possibly comprising a compression load. Modular assembly according to any one of the preceding claims, characterized in that said removable part (10) of said at least one module (1) comprises an interface, capable of executing an interrogation or measurement system. Modular assembly according to any one of the preceding claims, characterized in that said removable part (10) of said at least one module (1) comprises at least one thermal insulation wall (21). Modular assembly according to claim 14, characterized in that said at least one thermal insulation wall (21) extends all around the hot enclosure or only on the top of said hot enclosure, on the bottom of said hot enclosure and possibly on a front part and / or on a rear part of said hot enclosure. Assembly according to any one of the preceding claims, characterized in that it comprises several modules (1), each module comprising a first removable part (10), equipped with first connectors (4) for fluid conduits, which comprises said at least one stack (2) of solid oxide plates positioned in said hot enclosure (3), said fixed part (11) forming a common docking station for all the removable parts (10) of the modules (1), said fixed part (11) being equipped with second connectors (5) which assemble with and disassemble from said first connectors (4) of each removable part (10) received, said fluid distribution network (13) comprising said fluid supply conduits (14) and said fluid discharge conduits (15) being common to all the modules (1). Assembly according to claim 16, characterized in that said fixed part (11) forming a docking station comprises thermal insulation walls (24) which cover a set of side walls of removable parts (10) of the modules (1) accommodated in said docking station. Assembly according to claim 16 or 17, characterized in that it comprises removable inclusion devices (25), positioned in interstices between two removable parts (10) of adjacent modules (1).

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