Electrolysis system

Abstract

An electrolysis system (1) having an electrolyzer (2) designed to convert electrical energy to chemical energy, and having power electronics (4) for supply of the electrolyzer (2) with the required electrical power. The power electronics (4) comprise circuit components (7) and a rectifier (8). Also present is a busbar (14) for electrical connection of the power electronics (4) to the electrolyzer (2). The power electronics (4) comprise multiple strings (5), where each string (5) has circuit components (7) and a rectifier (8), and each string (5) is mounted in a housing (10). The electrolysis system (1) has a carrier frame (15) with multiple slots (16), where each slot (16) is designed to accommodate one of the housings (10) in an assembly position, such that the strings (5) are connectable to the busbar (14) in the assembly position.

Description

[0001] title

[0002] Electrolysis system

[0003] The invention relates to an electrolysis system comprising an electrolyzer for converting electrical energy into chemical energy and power electronics that provides the required electrical energy to the electrolyzer.

[0004] State of the art

[0005] Electrolysis systems are used to convert electrical current into chemical energy. In the case of water electrolysis, water is split into its components hydrogen and oxygen. Typically, only the hydrogen is reused, which can be stored and converted back into electrical, thermal, or mechanical energy when needed. The electrical current to operate the electrolysis system is provided by a power source, such as a wind turbine or a solar array, as direct or alternating current. Such an electrolysis system is known, for example, from DE 10 2018 215 698 A1.

[0006] The electrolyzer comprises one or more electrochemical stacks, each consisting of a multitude of electrochemical cells in which the actual electrochemical reaction takes place. The stacks must be supplied with a suitable direct current, which is provided by power electronics that include a rectifier, fuses, a contactor, and other electrical components. Such a supply unit is also called a string. Since the electrolyzer requires only a low direct voltage but a high current for a corresponding power output, the power electronics must be connected to busbars with a large cross-section to supply the stacks with the required current. In power electronics, various components can be present multiple times or only once.For example, the so-called switching components, such as fuses and contactors, can be installed only once, while the rectifiers for converting alternating current into direct current are installed multiple times. Which configuration is suitable depends on the required electrical power and the cost of the individual components.

[0007] Advantages of the invention

[0008] The electrolysis system according to the invention is easily scalable, allowing power electronics to be easily constructed across a wide power range while maintaining a high level of reliability. For this purpose, the electrolysis system comprises an electrolyzer designed to convert electrical energy into chemical energy and power electronics for supplying the electrolyzer with the required electrical current. The power electronics comprise a rectifier, a contactor, and a fuse. The power electronics comprise several strings, each string comprising a rectifier, a contactor, and a fuse, and each string is mounted in a portable housing.The electrolysis system further comprises a support frame with a plurality of slots, wherein each slot is designed to receive one of the housings in a mounting position and the strings are connectable to a busbar in the mounting position, wherein the electrical power transmitted by the strings is made available to the electrolyzer via the busbar.

[0009] The power electronics have a modular design and comprise several strings, which are preferably connected in parallel so that their current strengths add up. Each string has a slot into which the string and its housing can be inserted and secured in a mounting position. All strings can thus be easily connected to a common or multiple busbars, which serve to supply the electrolyzer with the necessary current. The modular design allows strings, which are preferably identical in design, to be easily replaced or removed without impairing the function of the other strings. This makes it possible to specifically replace or temporarily remove just the affected string in the event of a defect, while the remaining strings continue to supply the electrolyzer with electrical current.The electrolyzer can thus continue to operate at least at a reduced power, which increases reliability and thus also economic efficiency.

[0010] In a first advantageous embodiment of the invention, the string housings have output contacts that are directly connected to the busbar by inserting the housings into the slots and thus into the mounting position. This eliminates the need for a separate electrical connection between the strings and the busbar(s), simplifying the installation of the housings in the slots. Furthermore, the risk of incorrect installation, i.e., incorrectly connected strings to the busbars, is reduced or eliminated.

[0011] The strings are also advantageously connected in parallel so that their currents add up and can be fed to the electrolyzer via busbars. Electrolyzers are usually operated at a relatively low voltage but with very high currents, which requires busbars with a large cross-section to minimize losses. Parallel connection allows, in principle, any number of strings to be connected to provide the required current.

[0012] The strings are mounted in a housing, which can advantageously be designed as an open frame structure, as a semi-open frame structure with a partial cladding or as a closed housing, depending on the environment and the necessary safety regulations.

[0013] In a further advantageous development of the invention, the strings or their housings are releasably fixed in the support frame, e.g. by screw connections. This means that individual housings can be easily removed and replaced without impairing the function of the other strings. It is particularly advantageous if several or all of the strings and their housings are of identical design so that they can be easily replaced to replace individual defective strings, which can then be repaired separately and, if necessary, at a different location. In a further advantageous embodiment, the support frame is divided into several segments, with each segment comprising at least two slots for accommodating string housings. Such segments can be combined to form a large power electronics unit in order to be able to generate high power levels and currents.The modular design allows for easy stringing, as all segments advantageously feature partial busbars that can be easily connected to one another, e.g., by plugging them into one another. The partial busbars are advantageously mounted on a busbar support frame, which can be mounted on or at the support frame independently of the strings.

[0014] drawing

[0015] The drawing shows a schematic representation of an electrolysis system according to the invention.

[0016] Fig. 1 shows the schematic structure of the entire electrolysis system,

[0017] Fig. 2 a support frame without strings,

[0018] Fig. 3 shows a rail support frame with partial current rails, Fig. 4 shows a complete segment of the support frame and Fig. 5 shows an overall view of an electrolysis system with several segments.

[0019] Description of the embodiments

[0020] Fig. 1 shows the entire electrolysis system 1, with only the essential components being shown. The electrolysis system 1 serves, for example, to split water into hydrogen and oxygen using electrical energy, with the hydrogen being reused as an energy carrier, while the oxygen is either simply released into the ambient air or used for other purposes. The necessary electrical energy is supplied to the electrolysis system 1 via a power line 13 as alternating voltage and transformed to the required voltage in a transformer 3. The electrical energy can be generated, for example, using a wind turbine or a solar power system. The transformer 3 is connected to power electronics 4, which converts the electrical output voltage of the transformer 3 into the direct voltage required for the operation of the electrolyzer 2.The operation of an electrolyzer generally requires only low voltages, but correspondingly high currents to provide the required power. The actual splitting of water into hydrogen and oxygen takes place in electrolyzer 2. The devices for supplying electrolyzer 2 with water or electrolyte solution and for storing the resulting hydrogen are not shown here, as they are well known.

[0021] The power electronics 4 comprises several strings 5 ​​connected in parallel so that their output currents add up. Each string 5 provides a portion of the required electrical energy and includes switching components 7 and a rectifier 8. The switching components 7 include, in particular, fuses, contactors, and other elements to ensure safe operation of the power electronics 4. Due to the parallel connection, each string 5 contributes only a portion of the required power. If one string 5 fails, the remaining strings 5 ​​can continue to supply their electrical power, and the electrolyzer 2 can continue to operate—albeit at a lower power level.

[0022] Fig. 2 shows a support frame 15. This consists of an open frame structure with massive supports, wherein the support frame is divided into individual slots 16 by struts 17. The slots 16 serve to accommodate a string 5 or the housing 10 in which the string 5 is mounted. For example, the support frame 15 shown here has four slots, wherein the housings 10—which are not shown here for the sake of clarity—can be fixed in the support frame 15 by means of locking devices 18.

[0023] In order to conduct the current generated by the strings 5 ​​to the electrolyzer 2, the strings 5 ​​are connected to busbars 14. The busbars 14 - four here as an example - are mounted in a separate busbar support frame 19, as shown in Fig. 3, wherein the number of busbars 14 is adapted to the respective requirements. The busbar support frame 19 is designed to be mounted on the support frame 15, as shown in Fig. 4. The four housings 10 each contain a string 5, which are connected to the busbars 14 or the partial busbars 114 by output contacts 11. The output contacts 11 are manufactured such that they make direct contact with the busbars 14 when the housings 10 are inserted into the support frame 15.

[0024] Since high-performance electrolyzers 2 require a correspondingly high amount of electrical power, more than one support frame 15 can be used, forming a segment 20 within an overall support frame. Fig. 5 shows a possible arrangement of three segments 20 that provide the required electrical energy for an electrolyzer 2. Each of the segments 20 comprises four housings 10 with strings 5 ​​and a partial busbar 114. The partial busbars 114 are interconnected and form the busbar 14, which supplies the total power of all strings 5 ​​to the electrolyzer 2. In principle, any number of segments 20 can be combined to form an overall support frame, even to achieve very high power levels.

[0025] Because the partial busbars 114 are mounted on a separate busbar support frame 19, they can be installed independently of the strings 5. This simplifies the overall assembly, as the busbars 14 are correspondingly heavy due to their large cross-section. Since the slots 16 and the housings 10 of the strings 5 ​​are identical, both the support frame 15 and the housings 10 can be mass-produced and thus cost-effectively. Manufacturing from identical housings 10 also facilitates the replacement of individual defective strings 5 ​​if necessary.

Claims

Claims 1 . Electrolysis system (1) with an electrolyzer (2) which is designed to convert electrical energy into chemical energy, and with power electronics (4) for supplying the electrolyzer (2) with the required electrical current, wherein the power electronics (4) comprises switching components (7) and a rectifier (8), and with a busbar (14) for electrically connecting the power electronics (4) and the electrolyzer (2), characterized in that - the power electronics (4) comprises a plurality of strings (5), each string (5) comprising switching components (7) and a rectifier (8), and each string (5) is mounted in a housing (10), and - the electrolysis system (1) has a support frame (15) with a plurality of slots (16), wherein each slot (16) is designed to receive one of the housings (10) in a mounting position, so that the strings (5) can be connected to the busbar (14) in the mounting position.

2. Electrolysis system according to claim 1, characterized in that the housings (10) of the strings (5) have output contacts (11) which are connected to the busbar (14) by inserting the housings (10) into the mounting position.

3. Electrolysis system according to one of claims 1 or 2, characterized in that the output currents of the strings (5) in the busbar (14) add up so that the total output power of the strings (5) is available at the electrolyzer (2).

4. Electrolysis system according to one of claims 1, 2 or 3, characterized in that the housings (10) of the strings (5) are designed as an open frame structure, as a semi-open frame structure or as a closed housing.

5. Electrolysis system according to one of claims 1 to 4, characterized in that the housings (10) of the strings (5) are releasably fixed in the mounting position in the support frame (15) so that each of the strings (5) can be replaced independently of the other strings (5).

6. Electrolysis system according to one of claims 1 to 5, characterized in that several or all strings (5) are of identical construction.

7. Electrolysis system according to one of claims 1 to 6, characterized in that the support frame (15) is divided into several segments (20), each segment (20) comprising at least two slots (16) for receiving strings (5).

8. Electrolysis system according to claim 7, characterized in that each segment (20) has a partial busbar (114) which can be electrically connected to the strings (5) mounted in the segment (20).

9. Electrolysis system according to claim 8, characterized in that several segments (20) are arranged in a row such that the partial busbars (114) are electrically connected to one another.

10. Electrolysis system according to one of claims 8 or 9, characterized in that the partial current rails (114) are mounted in a rail support frame (19).

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