Water electrolyzer system

Abstract

The invention relates to a water electrolyzer system (1) for producing hydrogen. The water electrolyzer system (1) comprises an electrolysis stack (8) for converting water into hydrogen, power electronics (12) for transforming the alternating current into a direct-current in order to supply the electrolysis stack (8), components (56, 64, 72, 80) for preparing the process media supplied to and discharged from the electrolysis stack (8), and a control unit (18) for controlling the electrolysis stack (8), the power electronics (12), and the components (56, 64, 72, 80) for preparing the media. At least the electrolysis stack (8), the power electronics (12), and the control unit (18) are formed together as an electrolyzer module (36), and the components (56, 64, 72, 80) for preparing the media and for conveying the media are formed together as a process module (52). The modules (36, 52) are equipped with connection possibilities (32, 40, 48, 84), via which the individual modules (36, 52) can be fluidically and electrically connected together.

Description

[0001] Description

[0002] Title:

[0003] Water electrolyzer system

[0004] The present invention relates to a water electrolyzer system for producing hydrogen. Furthermore, the invention relates to a hydrogen factory comprising at least one such water electrolyzer system.

[0005] State of the art

[0006] The core of a PEM water electrolyzer is the electrolysis stack. The general trend for industrial hydrogen production is toward very powerful units with multiple MW of power. The electrolyzer also includes various supply units, the so-called Balance of Plant (BoP). These units include water pumps, gas-water separators, ion filters, heat exchangers, temperature sensors, pressure sensors, gas sensors, ultrapure water treatment, hydrogen post-treatment and purification, transformers, rectifiers, control and monitoring units, cables, pipes, and valves. How these components are connected to each other and whether these components supply one or more stacks is at the manufacturer's design discretion. Depending on the design principle, different configurations and pre-assembled units can be advantageous.

[0007] DE 10 055 973 A1 discloses an offshore power plant with several individual power plants, each with its own energy storage device. The power plants are electrically connected to a busbar. The energy storage devices include electrolyzers, which can produce hydrogen and oxygen from water stored in pressure tanks. A fuel cell arrangement is arranged in the energy storage device, which can generate electrical energy from the hydrogen.

[0008] DE 20 2019 003 849 U1 discloses a system for energy generation and energy management. The system comprises several solar panels and several wind turbines for generating energy. The system has one or more electrolyzers, which can be used to produce hydrogen, oxygen, and water.

[0009] When installing an electrolyzer at the customer's site (e.g., next to a solar field), the main costs are transport to the construction site and the effort required for assembly and commissioning. While the delivery of individual components may be cost-effective in terms of transport, assembly and commissioning require a significant amount of time and personnel.

[0010] The object underlying the invention is to provide a water electrolyzer system with which a simpler, faster and more cost-effective construction of such a system is possible.

[0011] The object is achieved by a water electrolyzer system having the features of patent claim 1. Preferred embodiments can be found in the dependent claims.

[0012] Disclosure of the invention

[0013] The invention specifies a water electrolyzer system for producing hydrogen. The water electrolyzer system comprises at least one electrolysis stack for converting water into hydrogen, power electronics for supplying the electrolysis stack, components for media preparation and conveying the process media supplied to and discharged from the electrolysis stack, and a control unit for controlling the electrolysis stack, the power electronics, and the components for media preparation and conveying. At least the electrolysis stack, the power electronics, and the control unit are configured together as an electrolyzer module, and the components for media preparation and conveying are configured together as a process module. Connection options are provided on the modules, via which the individual modules can be fluidically and electrically connected to one another.

[0014] The electrolysis stack is advantageously a PEM electrolysis stack. A module, within the meaning of the invention, is understood to be a structural unit that is manufactured together in a manufacturing factory. These modules are preferably manufactured automatically. After production, the modules are transported, for example, by truck or ship, to the location where a hydrogen factory is to be built or expanded. According to the invention, the electrolyzer system comprises only the assemblies of the electrolysis module, the process module, and the control module. Depending on the size of the hydrogen factory, several of these modules can be provided. Automated production in the factory significantly reduces the time and personnel required to assemble and connect the individual components and the costs of such a system.

[0015] The modules can be constructed and expanded using a modular principle. The modular design also reduces transport costs, as combining the individual components into modules means fewer trips are necessary to bring all components to the site. To ensure easy transport of the electrolyzer module, the electrolysis stacks have a maximum output of 1 MW. At this output, the weight does not exceed the limit required for transportability. The electrolysis stacks' output is preferably between 500 kW and 1500 kW. On site, the modules only need to be connected using the connection options, which can be standardized, for example. Only cables are required between these connection options, which reduces the number of cables. This also reduces the effort required to connect the modules to one another.In preferred embodiments, the electrolyzer module or the entire water electrolyzer system is housed in a sea freight container housing. In an advantageous further development, the power electronics are designed to transform alternating current into direct current. Direct current must be applied to the electrolysis stacks. If the water electrolyzer system is supplied with alternating current, a corresponding transformation is necessary.

[0016] In a preferred embodiment of the invention, the connection options are designed as plug-in and / or flange connections. The use of plug-in and flange connections has the advantage that connections do not have to be made using, for example, complex welding. This can save costs for a welder. Furthermore, the connections can be formed quickly, for example, by tightening screws. This allows the modules to be connected quickly and cost-effectively.

[0017] In a further preferred embodiment of the invention, the modules are connected to each other exclusively with prefabricated process media and power lines. In other words, the prefabricated process media and power lines have already been manufactured, for example, in an automated production process. These only need to be connected to establish the connection points. Thus, no complex connecting lines need to be laid. This also significantly reduces the manufacturing costs of such a water electrolyzer system and the time required for this.

[0018] Particularly preferably, a power line is designed as a common busbar that extends into both the electrolyzer module and the process module. All electrical consumers of the electrolyzer module and the process module can be connected to the busbar and are therefore preferably supplied with electrical power only via this busbar.

[0019] Advantageously, a process module is connected to several electrolyzer modules. This allows such a water electrolyzer system to be scaled to larger plants. Depending on the capacity, individual components for media preparation and media conveyance can be assigned to the process module, thus supplying several electrolyzer modules, or to the individual electrolyzer modules themselves, thus supplying only one electrolyzer module at a time. The water electrolyzer system thus remains variable, especially in its capacity.

[0020] In advantageous embodiments, the electrolyzer module comprises multiple electrolysis stacks. This is particularly advantageous when the installation space – for example, a sea freight container – allows for the arrangement of multiple electrolysis stacks in one electrolyzer module. This is also advantageous when multiple electrolysis stacks can share a control unit of the electrolyzer module.

[0021] Preferably, the connection option is designed such that a data connection and a power connection can be connected via a common plug. The plug thus has contacts for establishing both a power connection and a data connection. Thus, only a single plug is required to ensure a power and data connection. A plug has the advantage that no tools are required to prepare the power and data cables for a connection and to connect them. This allows for quick and easy connection.

[0022] Advantageously, the plugs are designed to be interchangeable, so that even a non-expert in this field can connect them correctly.

[0023] In an advantageous development, the process module additionally includes a pump for circulating the water through the electrolysis stack. The arrangement of the pump in the process module has the advantage that the pump can supply multiple electrolyzer modules.

[0024] In an alternative advantageous development, the electrolyzer module includes the pump for circulating the water through the electrolysis stack. Locating the pump in the electrolyzer module, rather than in the process module, has the advantage that a smaller pump can be used for each electrolyzer module. Furthermore, if the pump fails, not all electrolyzer modules are deactivated, but only the electrolyzer module in which the pump is located. This allows the water electrolyzer system to continue operating, thus creating redundancy. If a pump fails and metal chips are fed into the electrolysis stack, only this electrolysis stack needs to be replaced, instead of all electrolysis stacks.

[0025] Advantageously, the modules are designed so that their size is smaller than or equal to the size of a sea freight container. The size of such a sea freight container is defined according to the ISO standard. The advantage of such containers is that they can be easily transported by ship, rail, or truck. This eliminates the need for heavy-duty transport and a dedicated transport route to transport the modules to the installation site. This significantly reduces the costs and time required to transport the components.

[0026] In a further advantageous embodiment, the electrolyzer module and the control unit together have a common connection to the process module. A common connection means that the connections of the control unit and the electrolyzer module are arranged directly next to each other. Thus, only the process module needs to be connected to the common connection. This further simplifies the connection of the modules, so that only power and process lines need to be provided between the common connection and the process module.

[0027] The common connection option is advantageously arranged in such a way that, when the modules are positioned, the distance between the common connection option and a connection option on the process module is minimal or directly opposite each other.

[0028] According to a practical embodiment, several electrolyzer modules form a common connection to the process module. The several electrolyzer modules are thus arranged in a common housing. Within the housing, the process and data lines of the electrolyzer modules are interconnected and provide a single common connection for all electrolyzer modules to the process module on the housing. The connections between the electrolyzer modules are preferably carried out automatically, during module manufacture. The manufacturing costs of connecting the electrolyzer modules to each other are thereby reduced, as these connections do not have to be formed on-site. Thus, only one connection needs to be established between the common connection and the process module.

[0029] A hydrogen factory is also specified, which comprises at least one such water electrolyzer system. Such a hydrogen factory essentially achieves the aforementioned advantages. Such a hydrogen factory can thus be constructed quickly, economically, and easily. Furthermore, the modular design ensures easy expansion of the hydrogen factory, particularly its capacity.

[0030] Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. They show:

[0031] Figure 1 Water electrolyzer system according to an embodiment of the invention.

[0032] Figure 2 Water electrolyzer system according to another embodiment of the invention.

[0033] Figure 1 shows a water electrolyzer system 1 according to an embodiment of the invention. The water electrolyzer system 1 according to the embodiment comprises two electrolysis modules 4, each of which has an electrolysis stack 8 (shown only for one electrolysis module) for converting water into hydrogen. Additionally, power electronics 12 is arranged in the electrolysis module 4, via which a supplied alternating current is preferably converted into direct current. Furthermore, a pump 16 is arranged in the electrolysis module 4, with which water or the process medium can be circulated through the electrolysis stack 8.

[0034] The water electrolyzer system 1 additionally comprises a control unit 18, which is arranged in a control unit 20. The control unit 18 is connected via control data lines 24 to the electrolysis modules 4 for controlling the electrolysis stacks 8, the power electronics 12, and the pump 16. The control data line 24, together with a power line 28, is connected to a common first electrolysis module connection option 32. Both lines 24, 28 can be connected via a common plug to the first electrolysis module connection option 32, which is designed as a socket.

[0035] In this exemplary embodiment, the two electrolysis modules 4 and the control unit 18 are arranged in a common electrolyzer module 36, which is preferably housed in a housing, for example, a sea freight container. A second electrolysis module connection point 40 is arranged on the electrolysis modules 4, via which the process media lines 44 of the electrolysis modules 4 are connected to a common housing connection point 48. A control data line 24 of the control unit 18 is also connected to this common housing connection point 48.

[0036] The water electrolyzer system 1 additionally comprises a process module 52, which has various components for preparing and conditioning the process media. In the exemplary embodiment shown, the process module 52 has a heat exchanger 56, with which the cooling water for the power electronics 12 and the water for the electrolysis stack 8 are cooled. The heat exchanger 56 is connected to a cooling water connection 60 for this purpose. A cathode gas-water separator 64 is also arranged in the process module 52, in which the hydrogen coming from the cathode is separated from the cathode process medium and fed to a hydrogen connection 68. Furthermore, an anode gas-water separator 72 is arranged in the process module 52, in which the oxygen is separated from the anode process medium and fed to an oxygen connection 76. The process medium is deionized in an ion exchanger 80 for use in the electrolysis stack 8.

[0037] The process module 52 has a common process module connection option 84, to which the components of the process module 52 are connected. The housing connection option 48 is connected to the process module connection option 84 via connecting lines 88.

[0038] In preferred embodiments, the power line 28 is designed as a common busbar. Both electrolysis modules 4, as well as the control module 20 and the process module 52, have electrical connections to this common busbar.

[0039] Figure 2 shows a further water electrolyzer system 1 according to a further embodiment of the invention. The water electrolyzer system 1 has two electrolysis modules 4, each with an electrolysis stack 8 and power electronics 12. The power electronics 12 preferably each have network transfer switches and / or transformers. The two electrolysis modules 4, together with the control unit 18, form an electrolyzer module 36. The water electrolyzer system 1 further comprises a process module 52. The process module 52 contains the pump 16, the heat exchanger 56, the cathode gas-water separator 64, the anode gas-water separator 72, and the ion exchanger 80.

[0040] Process media lines 44 are arranged between the electrolyzer module 36 and the process module 52, via which the media lines (in particular water and hydrogen) run between the two modules 36, 52.

[0041] In preferred embodiments, the water electrolyzer system 1 further comprises the busbar 28, which is designed as a common power line and extends into both the electrolyzer module 36 and the process module 52. The electrical consumers, such as the electrolysis stacks 8, the pump 16, and the control unit 18, have electrical connections to the busbar 28.

Claims

Claims 1. Water electrolyzer system (1) for the production of hydrogen, comprising at least: an electrolysis stack (8) for converting water into hydrogen, power electronics (12) for supplying the electrolysis stack (8), components (16, 56, 64, 72, 80) for media preparation and media conveyance of the process media supplied to and discharged from the electrolysis stack (8), and a control unit (18) for controlling the electrolysis stack (8), the power electronics (12) and the components (16, 56, 64, 72, 80) for media preparation and media conveyance, characterized in that at least the electrolysis stack (8), the power electronics (12) and the control unit (18) together form an electrolyzer module (36) and the components (16, 56, 64, 72, 80) for media preparation and media conveyance together form a process module (52), wherein the modules (36, 52) Connection options (32, 40, 48, 84) are provided, via which the individual modules (36,52) are fluidically and electrically connectable.

2. Water electrolyzer system (1) according to claim 1 , characterized in that the power electronics (12) is designed to transform an alternating current into direct current.

3. Water electrolyzer system (1) according to claim 1 , characterized in that the connection options (32, 40, 48, 84) are designed as plug and / or flange connections.

4. Water electrolyzer system (1) according to one of claims 1 to 3, characterized in that the modules (36, 52) are connected to each other exclusively by prefabricated process media and power lines (28). A water electrolyzer system (1) according to claim 4, characterized in that a current line (28) is configured as a common busbar, which projects into both the electrolyzer module (36) and the process module (52). A water electrolyzer system (1) according to any one of the preceding claims, characterized in that the electrolyzer module (36) has several electrolysis stacks (8). A water electrolyzer system (1) according to any one of the preceding claims, characterized in that the process module (52) is connected to one or more electrolyzer modules (36) by means of process media lines (44). A water electrolyzer system (1) according to any one of the preceding claims, characterized in that the connection option (32, 40, 48, 84) is configured such that a data connection and a power connection can be made via a common connector.A water electrolyzer system (1) according to any one of the preceding claims, characterized in that the connection (32, 40, 48, 84) is configured such that all process media can be connected via a common connector. A water electrolyzer system (1) according to any one of the preceding claims, characterized in that the process module (52) has a pump (16) for circulating the water through the at least one electrolysis stack (8). A water electrolyzer system (1) according to any one of claims 1 to 9, characterized in that the electrolyzer module (36) has a pump (16) for circulating the water through the at least one electrolysis stack (8). A water electrolyzer system (1) according to any one of the preceding claims, characterized in that the modules (36, 52) are configured as follows. that their size is smaller than or equal to the size of a sea freight container.

13. Water electrolyzer system (1) according to one of the preceding claims, characterized in that the electrolysis stack (8), the Power electronics (12) and the control unit (18) together have a common connection point (48) to the process module (52).

14. Water electrolyzer system (1) according to one of the preceding claims, characterized in that several electrolysis stacks (8) form a common connection point (48) to the process module (52).

15. Hydrogen factory comprising at least one water electrolyzer system (1) according to one of the preceding claims.

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