Method for producing electrolysis module and protection unit for electrolysis module

Abstract

The invention relates to a method for producing an electrolysis module (20) for an electrolysis plant (10) having a plurality of electrolysis modules (20), in which a plurality of electrolysis cells (12) are mechanically combined to form an electrolysis module (20), said cells being configured to be applied with an electrolysis current (48) in a specified operation in order to perform electrolysis of a substance arranged in a reaction chamber of the electrolysis cells (12), wherein the electrode terminals of the electrolysis cells (12) are electrically connected to one another in a predetermined electrical connection manner and to the module terminals (28) of the electrolysis modules (20). According to the invention, the electrolytic cells (12) are classified according to at least one electrical parameter before the electrolytic cells (12) are combined into the electrolysis module (20) by detecting at least one parameter of the respective electrolytic cell (12) by means of a measuring device. A respective cell (12) is assigned to one of a plurality of cell classes as a function of the detected value of the at least one parameter. The electrolysis module (20) is manufactured using only the cells (12) assigned to a single cell class.

Description

Technical Field

[0001] This invention relates to a method for manufacturing an electrolytic module for an electrolytic apparatus having multiple electrolytic modules, wherein multiple electrolytic cells are mechanically combined to form an electrolytic module, these electrolytic cells being configured to be subjected to an electrolytic current during predetermined operation to perform electrolysis on a substance arranged in a reaction chamber of the electrolytic cells, wherein the electrode terminals of the electrolytic cells are electrically connected to each other and to the module terminals of the electrolytic module according to a predetermined electrical wiring configuration. The invention also relates to a protection unit for an electrolytic module of an electrolytic apparatus having multiple electrolytic modules. Furthermore, the invention relates to a protector for an electrolytic apparatus having multiple electrolytic modules connected in series, the protector comprising: multiple protection units, wherein each electrolytic module is electrically coupled to a corresponding protection unit; at least one electrical energy source for providing electrical power to the protection units; and a control unit for individually controlling the protection units. Finally, the invention also relates to an electrolytic apparatus having multiple electrolytic modules connected in series and a protector electrically coupled to these electrolytic modules. Background Technology

[0002] Electrolysis equipment, protectors, protection units for protectors, and methods for manufacturing electrolysis modules are well known in the prior art, and therefore, specific written evidence is generally unnecessary. Electrolytic cells and equipment of common types, particularly those for electrolyzing water into hydrogen and oxygen, are well known in the prior art, for example, as described in DE 19729 529 C1. The basic functions of electrolysis, particularly water electrolysis, are known to those skilled in the art, and therefore, detailed descriptions are not provided here.

[0003] Electrolysis equipment having a single electrolysis module, but particularly multiple electrolysis modules typically at least partially connected in series, is especially used for producing substances preferably usable on an industrial scale, such as hydrogen in water electrolysis and carbon monoxide in carbon dioxide electrolysis. For this purpose, a suitable small DC voltage, in the range of a few volts, is applied to at least two terminals of the respective electrolysis module. Corresponding to the quantity of substance to be provided by electrolysis, a corresponding DC current is provided as the electrolysis current by the electrolysis energy source. For electrolysis modules connected in series, this DC current flows through all the series-connected electrolysis modules. This series connection is electrically coupled to the electrolysis energy source. However, in principle, electrolysis modules can not only be connected in series, but also at least partially connected in parallel.

[0004] Specifically, in water-based electrolysis systems such as chlorine / alkali electrolysis and PEM electrolysis, membranes are typically installed in the respective electrolytic cells within the electrolysis module. These membranes separate the corresponding reaction chambers or reaction zones of the electrolytic cells, where corresponding electrodes are arranged. Typically, a catalyst is placed on this membrane to enable or accelerate the electrolysis process. Electrolysis is usually carried out by applying an electrolytic current or a suitable DC voltage, also known as cell voltage, to the electrodes of the respective electrolytic cell during specified operation.

[0005] It has been shown that, at least partially critically, the transition from an operating state different from the prescribed operating state used to perform electrolysis, or the change to an operating state different from the prescribed operating state used to perform electrolysis, is particularly important for the electrolytic cell. This involves, in particular, the activation and deactivation of the electrolytic module of the electrolytic cell or electrolytic equipment. Especially when deactivated after prescribed operation, residual substances, particularly residual gases, may still be present in the electrolytic cell, which in some cases may lead to fuel cell function within the electrolytic cell. However, this would irreversibly damage the electrolytic cell, and therefore fuel cell function must be avoided. For this purpose, it is known to apply a protective voltage, also known as a polarization voltage, to the electrolytic cell outside of prescribed operation, which is selected to avoid fuel cell function as much as possible. For individual electrolytic cells used for water electrolysis, the protective voltage may, for example, be approximately 1.25V. Once the electrolytic cell has been appropriately cooled and the residual gases removed, the application of the protective voltage can be stopped.

[0006] It has been shown that electrolytic cells may age differently and / or have different characteristics. This has proven problematic, particularly for series connections of electrolytic cells, where a protective voltage should be provided by applying a voltage to the series circuit. Due to the different aging or characteristics of the individual electrolytic cells connected in series, the voltage applied to the series circuit may not be uniformly distributed among all the connected electrolytic cells. Therefore, the voltage of the series circuit needs to be chosen to be large enough that the protective voltage can still be reliably achieved for the most unfavorable electrolytic cell. However, this also results in other electrolytic cells being subjected to correspondingly high voltages, which may be significantly higher than their required protective voltage, allowing these other electrolytic cells to continue operating in electrolysis. In particular, nitrogen purging is typically used to avoid the formation of explosive mixtures in these electrolytic cells.

[0007] As is also known from EP 3 982 501 A1, a protective voltage is applied individually to each electrolytic cell. However, providing the appropriate protective voltage to the electrolytic cell, and the associated substantially constant DC current, has proven to be relatively complex.

[0008] Depending on the manufacturer, production batch, and / or similar circumstances, electrolyzers can have very different characteristics, particularly in terms of protective features to prevent fuel cell operation. Summary of the Invention

[0009] The objective of this invention is to reduce the cost of reliable protection functions used to prevent the operation of fuel cells in corresponding electrolyzers. Furthermore, providing corresponding methods, protection units, corresponding protectors, and corresponding electrolysis equipment is also an objective of this invention.

[0010] Regarding this type of method, the present invention specifically proposes to classify the electrolytic cells according to at least one preferred electrical parameter before assembling them into an electrolytic module by means of a measuring mechanism to detect at least one parameter of the corresponding electrolytic cell, to assign the corresponding electrolytic cell to one of a plurality of electrolytic cell categories according to the value of the detected at least one parameter, and to manufacture the electrolytic module using only the electrolytic cells assigned to a single electrolytic cell category.

[0011] Regarding this type of protection unit, the present invention specifically proposes that the electrolysis module is manufactured according to the present invention, wherein the protection unit has: at least two connection contacts for electrical connection to corresponding module terminals of the electrolysis module; at least two connection terminals for electrical connection to an electrical energy source; and a controllable power converter electrically coupled to the at least two connection terminals and the connection contacts, the power converter being configured to apply a DC current as a module protection current to the electrolysis module under an operating state different from that of the prescribed electrolysis operation.

[0012] Regarding this type of protector, the present invention specifically proposes that the protection unit be configured according to the present invention.

[0013] Regarding this type of electrolysis equipment, the present invention specifically proposes that the protector be configured according to the present invention.

[0014] The core concept of this invention is that by forming modules from electrolytic cells with substantially similar characteristics (in terms of undesirable fuel cell operation), a single protection unit can be used to protect all electrolytic cells within the electrolytic module from fuel cell operation. Therefore, it is no longer necessary to implement cell-specific protection functions for all electrolytic cells. This reduces the cost of protection functions. This is particularly effective for electrolysis equipment with a large number of electrolytic modules (each with a large number of electrolytic cells). Preferably, the electrolytic module generally possesses the characteristics of its electrolytic cells. This allows for reliable protection of the electrolytic cells of the respective electrolytic module using appropriately adapted protection units. Preferably, the electrolytic cells are in a state of performing prescribed electrolysis operation only after the electrolytic module has been manufactured.

[0015] The construction of the electrolysis module according to the invention also enables a reduction in the cost of controlling and / or maintaining the electrolysis equipment according to prescribed electrolysis operation. Using the electrolysis module according to the invention, individually operable units can be provided, which simplify the structure of the electrolysis equipment. It has proven particularly advantageous that fluid-technical terminals for the electrolytic cells can also be provided within the electrolysis module, thereby reducing the corresponding connection costs. Preferably, only the electrolysis module requires fluid-technical connection. Furthermore, the individual electrolysis modules can be inspected or monitored for their functionality. This allows for the provision of standardized components that simplify the structure and / or maintenance or monitoring of the electrolysis equipment. The manufacturing method preferably includes at least: inspecting the electrolytic cells for at least one parameter using a measuring mechanism; classifying the electrolytic cells based on the at least one parameter to assign them to corresponding, particularly parameter-specific, electrolytic cell categories; and, for example, combining, in particular connecting, a predetermined number of electrolytic cells of a single electrolytic cell category into an electrolysis module.

[0016] Electrolytic cell categories can be determined using at least one electrical parameter. To detect at least one electrical parameter, a suitable measuring mechanism is provided, capable of detecting the desired parameter of the electrolytic cell. For this purpose, the corresponding electrolytic cell can be detachably connected to the measuring mechanism accordingly. If necessary, the measuring mechanism can apply voltage and / or current to the corresponding electrolytic cell to detect or obtain the desired parameter. Based on the detected value of at least one parameter, the corresponding electrolytic cell is assigned to the corresponding electrolytic cell category. For example, this assignment can be achieved by determining a corresponding value range for the corresponding parameter for the corresponding electrolytic cell category. Furthermore, the electrolytic cells can be labeled accordingly, so that their belonging to the corresponding electrolytic cell category can be identified based on the label. Of course, the classification of electrolytic cell categories is not limited to the detection or determination of a single electrical parameter. Electrolytic cell categories can also be determined using multiple parameters. In this regard, it is possible that two electrolytic cell categories have the same first value range for a first parameter, but these two electrolytic cell categories can be distinguished by a second value range for a second parameter. Preferably, the electrolytic cell categories preferably have different value ranges from each other. At least one parameter may be the type of membrane in the electrolyzer, the catalyst used, the structure of the gas diffusion layer in the electrolyzer, and / or similar parameters. In particular, at least one parameter may be at least one electrical parameter, such as the electrolysis voltage, electrolysis current, capacitance, and / or similar electrical parameters generated during specified operation.

[0017] Electrolysis modules are manufactured using only electrolysis cells assigned to a single electrolysis cell category. This allows for a high degree of equivalence of the electrolysis cells within the corresponding electrolysis modules, and in particular, enables reliable protection of these electrolysis cells from harmful effects on fuel cell operation through a single protection unit for each electrolysis module.

[0018] For electrolysis equipment, it is not necessary to use electrolysis modules whose electrolytic cells are assigned to a single type of electrolytic cell. Instead, electrolysis modules with different types of electrolytic cells can be combined and operated within the electrolysis equipment. Protectors can be adapted to electrolysis modules with different electrolytic cells, thereby achieving the desired protection function even in such combinations. For this purpose, the protection unit of the protector can be electrically connected to one of the multiple electrolysis modules of the electrolysis equipment, thereby achieving module-specific protection functions. Therefore, the present invention further demonstrates that it can not only benefit the construction and manufacture of electrolysis equipment, but also the operation of electrolysis equipment, as will be shown below.

[0019] In an electrolysis module, the electrolytic cells are preferably mechanically connected to each other. For this purpose, the electrolysis module may have a frame or housing to which the electrolytic cells are connected. The frame or housing may also provide module terminals, and if necessary, fluid technology terminals, so that the electrolytic cells can be connected to the electrolysis equipment simply by setting up corresponding connections to the electrolysis module.

[0020] The protection unit is preferably an electronic or hardware circuit powered by an electrical energy source. This electrical energy source can be, for example, a DC voltage source. The electrical energy source can be designed to power multiple protection units. However, it can also be configured to power exactly one protection unit individually. For this purpose, the electrical energy source can be, for example, at least partially integrated into the protection unit. The electrical energy source can, for example, be power from a public power supply network or an energy storage device.

[0021] Furthermore, it is proposed that the cell resistance between the two electrode terminals of the corresponding electrolytic cell be used as a parameter. The measuring mechanism can be electrically coupled to the electrode terminals to determine the cell resistance. Preferably, the measuring mechanism can also be provided with terminals of a corresponding fluid technology, which are detachably connected to the corresponding electrolytic cell. To determine the cell resistance, it can be specified that the measuring mechanism applies a current or voltage to the corresponding electrolytic cell and accordingly detects and evaluates another electrical parameter to determine the cell resistance.

[0022] Furthermore, it is proposed to use the current of the electrolyzer as a parameter, whereby this current is the current generated at the electrode terminals of the electrolyzer when a protective voltage is applied to prevent fuel cell operation outside of the electrolyzer's prescribed electrolysis operation. This allows for the classification of electrolyzers, particularly tailored to desired protective functions.

[0023] Furthermore, it is proposed that, for at least one parameter, a separate value range, distinct from that of other electrolytic cell categories, be predefined for each electrolytic cell category. This avoids the corresponding electrolytic cell being multi-assigned to multiple electrolytic cell categories. The value ranges determining the electrolytic cell category do not need to be directly connected. It can be stipulated that electrolytic cells whose electrical parameters are not within any value range will be excluded. This can further improve the quality of the electrolysis equipment, as electrolytic cells with, for example, severely deviated characteristics will not be used in the manufacture of modules.

[0024] According to an improved embodiment, to manufacture an electrolysis module, a predetermined number of electrolytic cells of corresponding types are arranged adjacent to each other and mechanically connected to form the module. For example, the electrolytic cells can be connected by arranging them adjacent to each other and connecting them by means of mechanical connectors. Such connectors can be, for example, clips, screws, rivets, but can also be connecting pieces, snap-fit ​​pieces, combinations thereof, or the like. Furthermore, bonding, welding, or similar methods can be specified. Electrical connection of the electrolytic cells can also be achieved through the arrangement or mechanical connection of the cells. The electrolytic cells can preferably be connected in series, at least within the electrolysis module. However, in principle, parallel connection or array connection can also be considered. Particularly preferably, the arrangement or mechanical connection of the electrolytic cells can also achieve fluid technology coupling, through which the required fluids can be supplied to the electrolytic cells during the prescribed electrolysis operation. For this purpose, the electrolytic cells can be connected, for example, to a piping network on the module side to supply water and discharge hydrogen and oxygen.

[0025] An electrolysis module can be used to create individually operable components that can be inspected separately. An electrolysis module may have at least two electrolysis cells. However, preferably, the electrolysis module has multiple electrolysis cells, such as ten, twenty, or more.

[0026] Furthermore, it is proposed that, for manufacturing the electrolysis module, a predetermined number of electrolytic cells of corresponding types are installed in the module housing of the electrolysis module. The module housing may, for example, have a frame and / or housing walls, through which the electrolytic cells of the electrolysis module are at least partially isolated from the external environment. In addition, the module housing preferably provides electrical terminals and / or fluid technology terminals required for connecting the electrolytic cells. The module housing may also have module terminals, by means of which the module housing can be connected to the power supply section and / or fluid supply section of the electrolysis equipment.

[0027] Furthermore, it is proposed that when assigning electrolytic cells belonging to a specific electrolytic cell category to that category, the electrolytic cells should be marked according to the category, and / or stored in a storage area specifically assigned to that category. This allows for the selective provision of electrolytic cells belonging to a specific category for further processing in the manufacture of electrolysis modules. Marking can be implemented using marking elements, such as adhesive labels affixed to the electrolytic cells, color barcodes on the electrolytic cells, and / or similar elements. Alternatively or supplementarily, it can be specified that the electrolytic cells are stored in a separate storage area assigned to the corresponding category.

[0028] Furthermore, it is proposed that, in manufacturing electrolysis modules, only electrolysis cells labeled according to the corresponding electrolysis cell category be used, and / or only electrolysis cells from storage areas specifically allocated to the corresponding electrolysis cell category be used. In this way, it is possible to conveniently manufacture electrolysis modules with electrolysis cells of the corresponding electrolysis cell category.

[0029] According to another design, an electrolysis module is marked according to the type of electrolytic cell it is assigned to. Preferably, this marking is performed using a marking part, which can be, for example, disposed on the module housing. This marking part can be implemented in the same manner as the electrolytic cells. The marking part of the electrolysis module can be detected by a protection unit, for example. The protection unit can set the module protection current to be applied to the corresponding electrolysis module based on the detected marking part. This allows for automated, module-specific adaptation of the protection unit.

[0030] According to an improved design, the electrode terminals of the electrolytic cell are electrically connected to each other at least within the electrolysis module. This reduces connection and / or assembly costs. Simultaneously, this improvement provides at least partially a functionally superior unit, thereby facilitating inspection of the electrolysis module. It is also particularly advantageous that the fluid technology terminals of the electrolytic cell are at least partially formed within the electrolysis module.

[0031] Furthermore, it has proven advantageous to select the number of electrolytic cells in the electrolysis module according to the following requirements: when the electrolysis module operates under conditions different from its prescribed electrolysis operation, and a DC current serving as a module protection current is applied to the module terminals, fuel cell operation is prevented for all electrolytic cells in the electrolysis module. The number of electrolytic cells can be selected based on the value range of the electrolytic cell category and, if necessary, other boundary conditions, thereby reliably providing protection for all electrolytic cells in the corresponding electrolysis module through the protection unit. The number of electrolytic cells in the corresponding electrolysis module can, for example, be selected to be as large as possible so that the cost for the protection function can be kept as low as possible.

[0032] Specifically, regarding the protection unit, the energy converter is configured to apply a clock DC current as a module protection current to the electrolysis module. The protection unit is preferably applied with the voltage of an electrical energy source, thus enabling it to provide a corresponding protection current in the form of a clock DC current. The protection unit is preferably individually configured and electrically coupled to each electrolysis module. However, it may also be specified that the protection unit applies a protection current to two or more electrolysis modules, particularly those connected in parallel.

[0033] As a protective current for water electrolysis, this clock DC current can be selected within a certain range, such that it generates a voltage of approximately 1.35V to approximately 1.45V at the corresponding electrolytic cell as the cell voltage. Preferably, this voltage is greater than 1.25V. During prescribed electrolysis operation, the operating voltage is typically significantly greater than the protective voltage or the voltage achieved by the protective current. During prescribed electrolysis operation, the operating voltage at the corresponding electrolytic cell during water electrolysis can be approximately 1.9V. With suitable electrolytes and / or catalysts, this voltage can in some cases be as low as approximately 1.8V. However, these values ​​depend on the specific application and the substance to be electrolyzed. For the electrolysis of carbon dioxide or another substance, these values ​​may, of course, be significantly different in some respects.

[0034] A power converter or energy converter is used for the technical coupling of generating or providing energy between an electrical energy source and an electrolytic cell connected to a protection unit. A power converter, sometimes also called an energy converter, can be configured to couple the electrical energy source to the electrolysis module in a DC-isolated manner. The energy converter is used to convert electrical energy in a first form into at least one second form of electrical energy. The energy converter can be configured to perform energy conversion only in one direction. However, it can also perform energy conversion at least partially or temporarily in both directions. DC isolation or no potential currently means, in particular, that there is no need for an electrical connection with other potentials. The energy converter can be configured, for example, as an inverter or converter. With respect to the electrolysis module, the energy converter is preferably configured to provide a clock DC current with a settable amplitude and / or a settable duty cycle. Preferably, current control can be implemented.

[0035] However, the power converter can also be configured as a hardware circuit, a DC-DC voltage converter, etc. The power converter can have switching elements, or electronic switching elements, particularly semiconductor switches, for the desired switching function. In the sense of this disclosure, the switching element is preferably a controllable electronic switching element, such as a transistor, thyristor, or a combination thereof, particularly having parallel-connected unloaded diodes, such as a metal-oxide-semiconductor field-effect transistor (MOSFET), an insulated-gate bipolar transistor (IGBT), and preferably an integrated unloaded diode, etc. The switching element operates during switching operation.

[0036] The switching operation of a transistor-type semiconductor switch means that, in the on-state, a very low resistance is provided between the terminals forming the switching path of the transistor, making it possible to draw a large current with very low residual voltage. In the off-state, the switching path of the transistor is high-ohmic, meaning it provides high resistance, so that even if a high voltage is applied to the switching path, there is essentially no current or only a very low, in particular, negligible current. This differs from the linear operation of a transistor.

[0037] This improvement is based on the understanding that, during operation periods different from the prescribed operation, it is not necessary to apply a constant DC current to the electrolytic cell. Considering the capacitance of the corresponding electrolytic cell, the desired function can also be achieved using a clock DC current or a pulsed DC current. A clock DC current here means that the amplitude is not constant, but there is no change in the polarity of the DC current. Specifically, it can be specified that a current-controlled clock DC current is applied to the corresponding electrolytic modules in these electrolytic modules. Thus, it can be determined whether the protection voltage has been reached based on the voltage detected as the module voltage at the corresponding electrolytic module. For this purpose, a corresponding sensor unit can be provided, which is also electrically coupled to the module terminals of the corresponding electrolytic module. Here, the main idea behind this improvement is that the electrolytic cell, and therefore the electrolytic module, can exhibit capacitor-like electrical characteristics. Therefore, by setting a clock DC current, the desired protection function can be achieved in a simple way. It proves advantageous here that it is not necessary to precisely regulate the protection voltage and correspondingly provide a constant DC current. This is particularly advantageous in terms of the cost of providing the DC current. In particular, expensive filtering units on the DC side can be reduced or even avoided.

[0038] The clock DC current can have a predetermined or predeterminable frequency or clock rate. Preferably, a predetermined or predeterminable frequency or clock rate here means, according to a specified procedure, that the frequency or clock rate is substantially constant over at least a predetermined number of clock cycles. The frequency or clock rate can be predetermined primarily based on the minimum or average value of the detected module voltage, a predetermined minimum module current, a predetermined average module current, etc. For example, the clock DC current reaches zero during at least one clock interval. The clock DC current can have a predetermined or predeterminable duty cycle. The duty cycle can be specified to be set according to the cell voltage. Preferably, the clock DC current has a substantially fixed frequency.

[0039] The module voltage is the voltage between at least two terminals of the electrolytic module. The module voltage can be detected continuously and / or discretely over time. The detected module voltages can be averaged. For example, the module voltage can also be detected only during clock intervals or current pulses of the clock DC current. Preferably, when detecting the module voltage, it is also determined whether the detection occurs during a clock interval or current pulse.

[0040] Preferably, the electrolytic cell arranged in the corresponding electrolysis module is a PEM electrolytic cell. A PEM electrolytic cell is an electrolytic cell with a proton exchange membrane, which is also commonly referred to as a proton exchange membrane (PEM) or polymer electrolyte membrane (PEM). PEM is a semi-permeable membrane typically made of ionomers. PEM allows protons to pass through while essentially preventing the transport of gases such as oxygen or hydrogen. PEM is made, for example, of a pure polymer or of a composite membrane in which other materials are embedded within a polymer matrix. Commercially available PEM is, for example, Nafion from the chemical company DuPont. The advantage of PEM electrolytic cells is that, particularly compared to alkaline electrolytic cells, the leakage resistance can be significantly lower. Therefore, not only can higher efficiency be achieved compared to alkaline electrolytic cells, but also a larger specific area time constant can be achieved. Thus, a large time constant can be achieved using PEM electrolytic cells, especially for electrical parameters such as cell voltage and cell current. This can affect the setting of the clock DC current.

[0041] Of course, the advantages and effects provided for the method according to the invention also apply to the electrolysis apparatus according to the invention, the protection unit according to the invention, and the protector according to the invention, and vice versa. In this regard, method features can also be described as apparatus features, and vice versa.

[0042] For application cases or situations that may arise when referring to the method but are not explicitly described here, it may be specified that, according to the method, error messages and / or requests for user feedback can be output, and / or standard settings and / or predetermined initial states can be set.

[0043] Regardless of the grammatical gender of a particular term, words with masculine, feminine, or other parts of speech are included.

[0044] The embodiments explained below relate to preferred embodiments of the invention. The features and combinations of features given above in the specification, as well as those mentioned in the following description of the embodiments and / or shown separately in the drawings, can be used not only in the corresponding given combinations but also in other combinations. Therefore, the invention also includes embodiments that are also considered disclosed, which are not explicitly shown and explained in the drawings but can be derived and produced by the explained embodiments through individual combinations of features. The features, functions, and / or effects shown according to the embodiments can independently represent various features, functions, and / or effects of the invention to be considered independently of each other, and can also independently improve the invention. Therefore, the embodiments should also include combinations other than those in the explained embodiments. Furthermore, the described embodiments can be supplemented by other features, functions, and / or effects of the invention already described. Attached Figure Description

[0045] In the accompanying drawings, the same reference numerals denote the same features and functions.

[0046] Figure 1 An electrolysis device is schematically illustrated, which has multiple electrolytic cells connected in series, and these electrolytic cells are connected to an electrolysis energy source and an auxiliary energy source connected in parallel with the electrolysis energy source.

[0047] Figure 2 The schematic graph illustrates the following based on Figure 1 The polarization characteristic curves of the electrolytic cell of the electrolytic equipment are shown, which show the cell voltage related to the electrolytic current of the electrolytic cell;

[0048] Figure 3 A portion of an electrolysis device with an electrolysis module is shown in a schematic connection diagram;

[0049] Figure 4 A schematic graph is shown, in which the corresponding lines illustrate the calculations based on... Figure 1 The clock current, cell voltage, and control signal used for the protection current of the electrolytic cell;

[0050] Figure 5 It shows according to Figure 3 A schematic block diagram of the protection unit.

[0051] Figure 6 It shows according to Figure 3 A schematic flowchart of the manufacturing method of the electrolysis module; and

[0052] Figure 7 A schematic diagram of the manufacturing process of the electrolysis module is shown. Detailed Implementation

[0053] Figure 1 A schematic connection diagram of an electrolysis apparatus 52 having multiple electrolytic cells 12 connected in series is shown. The electrolytic cells 12 are currently used to electrolyze water into hydrogen and oxygen in reaction chambers (not shown further), which are constructed between the respective electrodes of the respective electrolytic cells 12. Of course, in alternative designs, other substances can also be electrolyzed here to convert them into corresponding substances.

[0054] The electrolytic cell 12, connected in series, is connected to the main rectifier 14, which serves as the energy source for electrolysis. The main rectifier 14 provides an operating voltage 50, which is applied to the series circuit of the electrolytic cell 12, so that an electrolytic current 48 flows through the electrolytic cell 12 during operation, specifically during electrolysis.

[0055] A series circuit consisting of a polarization rectifier 54 and a protective inductor 58 as an auxiliary power source is connected to the series circuit of the electrolytic cell 12 in parallel with the main rectifier 14. The polarization rectifier 54 and the protective inductor 58 are used to apply a rectifier voltage 68 to the electrolytic cell 12 outside of the prescribed electrolytic operation. This rectifier voltage is selected to generate a protective current 56, which is further selected to apply at least a polarization voltage U0 to all electrolytic cells 12. Figure 2 This serves as a protective voltage. Therefore, unwanted processes in the electrolytic cell 12 should be avoided outside of the prescribed electrolytic operation.

[0056] Figure 2 A schematic graph 60 is shown, where the vertical axis 62 represents the cell voltage at the corresponding cell terminal of a single electrolytic cell among the plurality of electrolytic cells 12. The horizontal axis 64 represents the corresponding cell current of that electrolytic cell 12. Graph 66 illustrates the relationship between cell voltage and cell current. N This represents the electrolytic voltage generated at electrolytic cell 12 when an electrolytic current of 48 is applied to it during the prescribed electrolytic operation. The intersection of line 66 and the vertical axis 62 defines the polarization voltage U0, which, if lower than this voltage, will cause a change in the polarization of the cell current.

[0057] In the current design of electrolytic cells used for water electrolysis, the electrolysis voltage U NThe voltage is approximately 1.8 to 1.9 V. However, in alternative embodiments, the electrolysis voltage can also be approximately 2.0 V to approximately 2.5 V. In the current design, the polarization voltage U0 can be approximately 1.48 V. Depending on the structure of the electrolytic cell 12, the polarization voltage U0 can also be in the range of approximately 1.1 V to approximately 1.45 V. When the cell voltage is greater than approximately 1.48 V, the electrolytic cell 12 typically exhibits electrolysis function, producing hydrogen and oxygen. However, the electrolysis function typically begins at around 1.1 V, and the electrolysis function increases with increasing voltage.

[0058] In this regard, according to Figure 1 Electrolysis unit 52 has proven disadvantageous because gases are generated even outside of the actual electrolysis process or the prescribed electrolysis operation. In such cases, unpredictable conditions may arise within electrolysis unit 52, which in the worst-case scenario could even lead to the formation of an ignitable gas mixture. To ensure safety in this situation, supplementary and comprehensive protective measures are required.

[0059] Furthermore, particularly when the electrolysis unit 52 is in operation or decommissioned, uneven distribution of the protection voltage across the series-connected electrolysis cells 12 may result in one or more electrolysis cells 12 having a voltage lower than the polarization voltage U0. This problem is especially likely to occur because the electrolysis cells 12 are not all identical and / or have different aging conditions. This can lead to undesirable fuel cell operation, potentially damaging the respective electrolysis cells 12.

[0060] Figure 3 A portion of an electrolysis apparatus 10 having an electrolysis module 20 is now shown, in which the aforementioned problems can be reduced (if not completely avoided). The electrolysis apparatus 10 is based on... Figure 1 The electrolysis equipment 52 is the same as that of electrolysis equipment 52; therefore, please refer to the relevant description for supplementary information. A series circuit consisting of multiple electrolytic cells 12 is also provided here, connected in parallel with the main rectifier 14, so that electrical energy can be supplied during the prescribed electrolysis operation. In this respect, electrolysis equipment 10 is consistent with electrolysis equipment 52; therefore, please refer to the description for electrolysis equipment 52. Figure 1 and Figure 2 The corresponding explanations provided.

[0061] According to Figure 1 Different design schemes, based on Figure 3In the electrolysis equipment 10, it is specified that every four electrolytic cells 12 are combined to form an electrolysis module 20. The electrolysis modules 20 formed in this manner are connected in series to the main rectifier 14. These electrolysis modules 20 are substantially identical in construction. Within each electrolysis module 20, the four electrolytic cells 12 are also connected in series. Each electrolysis module 20 has two module terminals 28, and the series circuit of the electrolytic cells 12 is connected to these module terminals.

[0062] The electrolysis unit 10 also includes a protector 16, which has a protection unit 30 for each electrolysis module 20. Each protection unit 30 has two connection contacts 26, which are electrically connected to the corresponding module terminals 28. The protection unit 30 is used to provide a separate protection current 74 for each series-connected electrolysis module 20. Figure 4 ).

[0063] Protector 16 is connected to electrolysis module 20, more specifically, to its module terminals 28. Protector 16 has an auxiliary voltage source 22 as an electrical energy source for providing auxiliary DC voltage 24. Therefore, in the current design, all module terminals 28 are electrically coupled to protector 16.

[0064] Furthermore, each protection unit 30 has two connection terminals 34, which allow it to be electrically coupled to the auxiliary voltage source 22. This enables the application of a protection current 74 to each electrolysis module 20 individually, ensuring that, outside of the prescribed electrolysis operation, all electrolysis cells 12 of the corresponding electrolysis module 20 can reliably achieve a cell voltage higher than the polarization voltage U0.

[0065] The auxiliary voltage source 22 can be electrically coupled, for example, to a public power supply network. Each protection unit 30 provides a separate protection current 74 to the corresponding electrolysis module 20, thereby enabling a separate protection voltage U. S .

[0066] Protection voltage U S ( Figure 2 The process is selected such that no fuel cell effect occurs at any of the electrolytic cells 12 in the corresponding electrolysis module 20; that is, gaseous residues react in the corresponding electrolytic cell 12 according to the fuel cell principle to form water and thus release energy. This leads to significant aging of the corresponding electrolytic cell 12.

[0067] The protector 16 also has a switching unit (not shown) connected to the connection terminal 34 of the protection unit 30 and to the coupling contact 26. The switching unit is not mandatory for this invention and—depending on need—can be omitted or configured in a modified manner. In the current design, the switching unit is configured such that the protection unit 30 is electrically coupled to the coupling contact 26 according to the switching state of the switching unit to provide a protective current 74 at the connection terminal 34. This provides the possibility that the protection unit 30 is only electrically connected to the electrolysis module 20 when needed or desired based on the operating conditions of the electrolysis equipment 10. Therefore, if the electrolysis module 20 is operating as scheduled in electrolysis operation, the protection unit 30 can be deactivated relative to the electrolysis module 20 by means of the switching unit. Furthermore, for example, it can be specified that if it is desired to be able to detect the module voltage independently of the switching state of the switching unit, the voltage sensor 44 of the protection unit 30 for detecting the module voltage can be directly connected to the coupling contact 26.

[0068] The operation of the protector 16, and in particular the protection unit 30, is controlled by the control unit 18 of the electrolysis equipment 10. For this purpose, the control unit 18 may include control circuitry.

[0069] To control the protection unit 30, the current design specifies that the module current of the electrolysis module 20 is detected by a current sensor. The current sensor provides a corresponding sensor signal to the control unit 18, which evaluates the signal. Once the sensor signal is less than a predetermined comparison value, the switching unit switches from an off switching state to an on switching state. This means that, through the now activated protector 16, each electrolysis module 20 is subjected to a corresponding individual protection current 74.

[0070] Currently, these protection units 30 are of the same construction. However, these protection units can also be different if needed. (Refer to...) Figure 5 The schematic block diagram exemplarily illustrates one of the protection units 30. To provide a protective current 74, the protection unit 30 has an electronic voltage converter 42 electrically coupled to an auxiliary voltage source 22, which is currently designed as a DC / DC converter with DC-DC separation. Simultaneously, the voltage converter 42 is configured to output a predetermined protective current 74 according to a control signal. For this purpose, the voltage converter 42 is connected to a control unit 18 via an interface terminal 70. The control unit 18 provides corresponding control signals so that the electrolysis module 20 connected to the protection unit 30 can be subjected to a separate protective current 74.

[0071] Furthermore, the protection unit 30 has a voltage sensor 44 connected to terminal 26, which detects the module voltage of the electrolysis module 20. The corresponding sensor signal is transmitted from the voltage sensor 44 to the control unit 18 via interface terminal 70. The control unit 18 evaluates the sensor signal and determines the protection current 74 to be set accordingly. Based on the determined protection current 74, a control signal is transmitted to the voltage converter 42.

[0072] Currently, all protection units 30 of protector 16 are configured identically and can be controlled by control unit 32.

[0073] Figure 4 Using schematic curves to target based on Figure 3 One of the electrolytic cells 12 is exemplarily shown with a protection current 74 of a protection unit 30 coupled to the corresponding electrolytic cell 12. Figure 4 In the graph 80 shown, the left vertical axis represents voltage, and the right vertical axis represents current. The horizontal axis is a time axis in milliseconds (ms). Graph 76 shows the converter control signal inside the voltage converter 42, which controls the output of the protection current. Currently, the converter control signal is a rectangular signal, allowing the voltage converter 42 to provide a clock DC current. The clock DC current representing the protection current is shown in graph 76. It can be seen that the protection current 74 is switched on or off synchronously with the converter control signal 76.

[0074] During this operation, the module voltage of electrolytic module 20 is detected using a voltage sensor. Currently, no separate wiring is required for this. It can be seen that, due to the clock DC current serving as the protection current 74, electrolytic module 20 exhibits a DC voltage 78 with low amplitude fluctuations as its module voltage. Currently, the voltage fluctuation is in the range of approximately 1.25V to approximately 1.35V. The voltage curve shown in graph 78 is generated due to the capacitive effect of electrolytic cell 12. This also explains why, according to graph 76, the amplitude is not constant but slightly decreases during the corresponding duration of the corresponding DC current pulse. This is also a reaction caused by the capacitive characteristics of electrolytic cell 12.

[0075] Using the control signals of the control unit 18, the amplitude and duty cycle of the clock DC current can be set as needed. For this purpose, the control unit 18 can evaluate the sensor signal of the voltage sensor accordingly. In any case, the amplitude and duty cycle of the clock DC current are determined such that the detected module voltage of the electrolysis module 20 is sufficient to ensure that the cell voltage of the electrolytic cell 12 of the electrolysis module 20 is greater than the corresponding associated protection voltage.

[0076] The frequency of the clock DC current can be selected in the range of approximately 10 Hz to approximately 100 Hz. Preferably, the frequency is in the range of approximately 30 Hz.

[0077] Figure 6 A schematic flowchart of a method for manufacturing an electrolysis module 20 is shown.

[0078] according to Figure 3 Method for manufacturing the electrolysis module 20 of the electrolysis equipment 10.

[0079] Multiple electrolytic cells 12 are mechanically combined to form an electrolysis module 20. These cells are configured to be subjected to an electrolytic current 48 during predetermined operation to perform electrolysis on water arranged in the reaction chambers of the electrolytic cells 12. Before the electrolytic cells 12 are assembled into the electrolysis module 20, the cells 12 are classified in step 90 based on at least one cell resistance as an electrical parameter by detecting the cell resistance of the respective cells 12 using a measuring mechanism (not shown). In step 92, based on the detected cell resistance value, the corresponding electrolytic cell 12 is assigned to one of a plurality of electrolytic cell categories.

[0080] In order to manufacture the electrolysis module 20, in step 94 only the electrolysis cells 12 assigned to a single electrolysis cell category are selected.

[0081] In step 96, four electrolytic cells 12 belonging to a single electrolytic cell category are selected and arranged in the module housing 88 of the electrolysis module 20. Figure 7 In step 98, the electrode terminals of the electrolytic cell 12 are connected in series to each other and electrically connected to the module terminals 28 of the electrolysis module 20. Thus, the electrolysis module 20 is at least partially manufactured.

[0082] The embodiments are for illustrative purposes only and should not be construed as limiting the invention.

Claims

1. Method of manufacturing an electrolysis module (20) for an electrolysis plant (10), the electrolysis plant having a plurality of electrolysis modules (20), wherein, a plurality of electrolysis cells (12) are mechanically combined to form the electrolysis module (20), the electrolysis cells being configured to be applied with an electrolysis current (48) in a prescribed operation to perform electrolysis on a substance arranged in a reaction chamber of the electrolysis cell (12), wherein the electrode terminals of the electrolysis cells (12) are electrically connected to one another and to module terminals (28) of the electrolysis module (20) in a predetermined electrical wiring, characterized in that at least one parameter of the respective electrolysis cell (12) is detected by means of a measuring device, the electrolysis cells (12) are sorted according to at least one preferably electrical parameter before the electrolysis cells (12) are combined into the electrolysis module (20), the respective electrolysis cell (12) is assigned to one of a plurality of electrolysis cell categories depending on the value of the at least one parameter detected, and only electrolysis cells (12) assigned to a single electrolysis cell category are used to manufacture the electrolysis module (20).

2. The method of claim 1, wherein, The cell resistance between the two electrode terminals of the respective electrolysis cell (12) is used as the parameter.

3. The method according to any of the preceding claims, characterized in that, The current of the electrolysis cell (12) is used as the parameter, which is the current that occurs at the electrode terminals of the electrolysis cell (12) when the electrolysis cell (12) is applied with a protection voltage outside the prescribed electrolysis operation in order to avoid fuel cell operation.

4. The method according to any of the preceding claims, characterized in that, For the at least one parameter, a separate value range that is not identical to the value range of the other electrolysis cell categories is predetermined for the respective electrolysis cell category.

5. The method according to any of the preceding claims, characterized in that, To manufacture the electrolysis module (20), a predetermined number of electrolysis cells (12) of the respective electrolysis cell category are arranged next to one another and mechanically connected to one another to form the electrolysis module (20).

6. The method according to any of the preceding claims, characterized in that, To manufacture the electrolysis module (20), a predetermined number of electrolysis cells (12) of the respective electrolysis cell category are arranged next to one another and mechanically connected to one another to form the electrolysis module (20).

7. The method according to any of the preceding claims, characterized in that, When assigning the electrolysis cells (12) belonging to the respective electrolysis cell category to the respective electrolysis cell category, the electrolysis cells are labeled according to the respective electrolysis cell category and / or stored in a storage area that is exclusively assigned to the electrolysis cell category.

8. The method of claim 7, wherein, To manufacture the electrolysis module (20), only electrolysis cells (12) that are labeled according to the respective electrolysis cell category are used and / or only electrolysis cells (12) from the storage area that is exclusively assigned to the respective electrolysis cell category are used.

9. The method according to any of the preceding claims, characterized in that, The electrolysis module (20) is labeled in accordance with the case in which electrolysis cells (12) of the electrolysis module (20) are assigned to the respective electrolysis cell category.

10. The method according to any of the preceding claims, characterized in that, The electrode terminals of the electrolysis cells (12) are electrically connected to one another inside the electrolysis module (20).

11. The method according to any of the preceding claims, characterized in that, The number of electrolysis cells (12) of the electrolysis module (20) is selected in accordance with the requirement that, in an operating state of the electrolysis module (20) that is different from the prescribed electrolysis operation, a fuel cell operation is avoided for all electrolysis cells (12) of the electrolysis module (20) when a direct current is applied to the module terminals (28) of the electrolysis module (20) as a module protection current (74).

12. Protection unit (30) for an electrolysis module (20) of an electrolysis plant (10), the electrolysis plant having a plurality of electrolysis modules (20), wherein The electrolysis module (20) is manufactured in accordance with any of the preceding claims, the protection unit has: - at least two coupling contacts (26) for electrically connecting to respective module terminals (28) of the electrolysis module (20); - at least two connection terminals (34) for electrically connecting with an electric energy source (22); and - a controllable electric energy converter (42) electrically coupled with the at least two connection terminals (34) and the coupling contacts (26), the electric energy converter being configured to apply a direct current as a module protection current (74) to the electrolysis module (20) in an operating state different from a prescribed electrolysis operation.

13. The protection unit according to claim 12, characterized in that, The energy converter (42) is configured to apply a clocked direct current as the module protection current (74) to the electrolysis module (20).

14. Protector (16) for an electrolysis plant (10) having a plurality of electrolysis modules (20) electrically connected in series, the protector having: - a plurality of protection units (30), wherein, - each of the electrolysis modules (20) is electrically coupled with a respective protection unit (30); - at least one electric energy source (22) for providing electric energy to the protection units (30); and - a control unit (18) for individually controlling the protection units (30), characterized in that the protection units (30) are configured according to claim 12.

15. Electrolysis plant (10) having a plurality of electrolysis modules (20) electrically connected in series and a protector (16) electrically coupled with the electrolysis modules (20), characterized in that the electrolysis modules (20) are manufactured according to the method of any one of claims 1 to 11 and the protector (16) is configured according to claim 14.

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