Method for operating electrochemical device, electrochemical device

Abstract

The invention relates to a method for operating an electrochemical device (1), in particular an electrolysis device, comprising: at least one stack (2), in particular an electrolysis stack; the invention relates to an electrochemical device (1) comprising a stack (2), which is accommodated in a gas-tight closed volume (4) filled with a gas, in particular air and / or inert gas, and means (3) for electrical supply, the stack (2) being accommodated separately from the means (3) for electrical supply, the pressure (p1) in the volume (4) and / or the pressure (p2) in the environment or in another volume (5) being set such that the pressure (p1) is lower than the pressure (p2) during operation of the electrochemical device (1), components (3) for electrical supply are accommodated in the other volume. The invention also relates to an electrochemical device (1), in particular an electrolysis device, which is suitable for carrying out the method or can be operated according to the process.

Description

Technical Field

[0001] The invention relates to a method for operating an electrochemical device, in particular an electrolysis device. The invention also relates to an electrochemical device, in particular an electrolysis device, which is suitable for carrying out the method or can be operated according to the method.

[0002] The electrochemical system may be not only an electrolysis device, but also another electrochemical device, such as a fuel cell system. Therefore, the present invention is not limited to an electrolysis device.

[0003] A preferred field of application of the invention is hydrogen production. Background Art

[0004] Electrolysis is an electrochemical process in which an electric current is used to split chemical compounds. In the case of water electrolysis, hydrogen (H2) and oxygen (O2) are obtained from water (H2O).

[0005] The electrolysis is carried out in an electrolytic cell. The electrolytic cell comprises a large number of electrolytic chambers connected in a stack. Known examples are PEM electrolytic chambers (where PEM stands for "proton exchange membrane"), AEL electrolytic chambers (where AEL stands for "liquid alkaline electrolysis"), solid oxide electrolytic chambers or SOEC ("Solid Oxide Electrolyzer Cell") or AEM electrolytic chambers (where AEM stands for "anion exchange membrane"). Electrolysis in an electrolytic stack also requires an electricity supply, a water circuit and a gas preparation device, each having corresponding components and circuits. As a component, the electricity supply usually includes a transformer for converting alternating current AC ("Alternating Current") into direct current DC ("Direct Current") and a rectifier for adapting the DC voltage. As a component, the water circuit usually includes: a water preparation device to achieve the required low conductivity; a water pump for supplying water; and a gas-liquid separator for separating the product gases H2 and O2 from water. In addition, the water circuit can also include filters, ion exchangers, sensors and actuators. Gas preparation devices usually include gas drying and purification devices. Other components also include intermediate storage devices and compressors.

[0006] In the context of decarbonization, hydrogen production from renewable energy sources is becoming increasingly important. In addition to the pure growth of hydrogen electrolysis projects, the average size of each project and therefore the size of the electrolysis system to be realized are also increasing. Since the size of the stack is usually limited, a modular solution for the electrolysis system is required, which enables the construction and efficient operation of large equipment starting from a large number of stacks.

[0007] In order to meet current safety regulations, such as the EU's ATEX directive, the electrical supply is usually placed spatially separate from the stack, for example in another room or on another floor. In this way, it should be prevented that the gas or gas mixture released in the event of a leak is ignited by a spark. If there is no spatial separation, it must be ensured that a certain minimum distance is maintained. All these measures will lead to increased line costs, especially for electrical and data lines. Due to the large amount of material used, costs also increase. In addition, due to the increased resistance of longer lines, efficiency losses are caused. Summary of the invention

[0008] The object of the present invention is to reduce the line lengths while complying with the relevant safety regulations, in order to save costs and optimize the efficiency of the device, in particular at the interface between the power electronics and the stack. To achieve this object, a method having the features of claim 1 and an electrochemical device having the features of claim 4 are proposed. Further advantageous developments of the invention can be found in the corresponding dependent claims.

[0009] Method for operating an electrochemical device, in particular an electrolysis device, comprising at least one stack, in particular an electrolysis stack, and components for an electrical supply. The components for the electrical supply may in particular be rectifiers, transformers and / or other electrical or electronic components. The stack is accommodated separately from the components for the electrical supply in a gastightly closed volume filled with a gas, in particular air and / or an inert gas. During operation of the electrochemical system, a pressure p1 in the volume and / or a pressure p2 in the environment or in another volume accommodating the components for the electrical supply is set such that pressure p1 is less than pressure p2.

[0010] Since the pressure in the volume accommodating the at least one stack is lower than the ambient pressure or the pressure in another volume accommodating the components for the electrical supply, it is avoided that the gases escaping from the stack come into contact with the components for the electrical supply. This means that it is not necessary to implement a large spatial distance between the stack and the components for the electrical supply in order to minimize the risk of explosion and comply with the current safety regulations. As a result, all lines, especially electrical and data lines, can be kept short. Due to the short lines, material costs are saved. The efficiency of the device can also be increased. The device can also be configured to be very compact.

[0011] The implementation of the method requires an electrochemical device in which at least one stack is at least hermetically enclosed. The enclosure must be hermetically sealed relative to the environment and / or relative to a second volume that accommodates components for the electrical supply. For example, the enclosure can be a box or a container. The second volume can be constructed within the enclosure, but then separated from the first volume in a hermetically sealed manner. However, the second volume can also be constructed in its own enclosure, or the environment can also construct the second volume. It is important that during the operation of the electrochemical device, the pressure p1 is lower than the pressure p2 of the environment or another volume. For this purpose, a enclosure that can accommodate at least one stack and is hermetically sealed relative to the environment is basically sufficient.

[0012] In the case of a plurality of stacks, each stack can then be accommodated in its own airtight volume. Alternatively, a plurality of stacks can also be arranged together in an airtight volume. Ideally, the number of stacks in each airtight volume is limited, for example 8, 4 or 2 stacks in each volume. A large number of stacks distributed in a large number of airtight volumes enables the construction of large, high-performance devices.

[0013] According to a preferred embodiment of the invention, gas is extracted from the volume accommodating the at least one stack in order to set the pressure p1. This means that a negative pressure is generated in a targeted manner in the first volume accommodating the at least one stack. In this case, the components for the electrical supply do not have to be specially enclosed, but can be arranged in the environment outside the enclosure for the stack. In this case, the pressure p2 corresponds to the ambient pressure. The gas extracted from the volume accommodating the at least one stack is preferably discharged in a controlled manner by a correspondingly designed exhaust fan.

[0014] Alternatively or additionally, it is proposed that, in order to set the pressure p2, the volume accommodating the components for the electrical supply is charged with a gas, in particular air and / or an inert gas. This means that the pressure in the second volume is increased compared to the pressure in the first volume. For this purpose, the components for the electrical supply must be accommodated in a gas-tight enclosure or in a further gas-tight volume of the enclosure of at least one stack. If the enclosure is designed to be the first volume and the second volume, a particularly compact device can be achieved.

[0015] Furthermore, an electrochemical device, in particular an electrolysis device, is proposed, comprising:

[0016] at least one stack, in particular an electrolytic stack, which is accommodated in a first volume filled with a gas, in particular air and / or an inert gas, and

[0017] - A component for the electrical supply, which is accommodated in the second volume. In particular, the component for the electrical supply can be a rectifier, a transformer and / or other electrical or electronic components.

[0018] The two volumes are separated from each other in a gas-tight manner. In addition, there are means for reducing the pressure in the first volume and / or means for applying pressure to the second volume.

[0019] The proposed electrochemical device is particularly suitable for carrying out the method described above or can be operated according to the method. Thus, the same advantages can be achieved with the device. In particular, at least one stack and the components for the electrical supply can be arranged spatially close to each other, so that short electrical and / or data lines are achieved while complying with the relevant safety regulations.

[0020] The gas-tight separation of the two volumes can be achieved at least by making the volume accommodating the at least one stack gas-tight. Alternatively or in addition, the volume accommodating the components for the electrical supply can also be gas-tight. For example, at least one gas-tight volume can be realized by a gas-tight enclosure in the form of a box or container. The enclosure can also form both volumes simultaneously.

[0021] If the device comprises a plurality of stacks, each stack can be accommodated in its own airtight volume or in an airtight volume together with at least one other stack. When there are a plurality of stacks in a common airtight volume, the number of stacks in the volume is preferably limited, for example eight, four or two stacks per airtight volume. A large number of stacks distributed in a large number of airtight volumes enables the construction of a large, high-performance device.

[0022] According to a preferred embodiment of the invention, the first volume and the second volume are separated in a gas-tight manner by the wall of the enclosure in which at least the first volume is constructed. This means that at least the first volume is embodied to be gas-tight. Thus, in the event of a leak, the gas cannot escape out of the volume in an uncontrolled manner. Instead, the leak can be discharged in a targeted manner, for example via a discharge opening that generates a lower pressure. In this way, it is avoided that the escaping gas enters the second volume that accommodates the components for the electrical supply. Thus, the gas cannot be ignited by sparks or the like.

[0023] In an extension of the invention, it is proposed that the wall has at least one airtightly integrated wall lead-through for at least one electrical and / or data line. The wall lead-through can ensure the required electrical supply of at least one stack. In addition, the electrical and / or data lines can be guided to electrical components and / or parts installed in the stack or in the environment of at least one stack. For example, the data lines can be used to control valves. In addition, sensors integrated in at least one stack or in the stack environment can transmit data to a controller located outside the first volume.

[0024] Alternatively or additionally, it is proposed that the wall has at least one airtightly integrated connection device for at least one electrical and / or data line. In contrast to the wall lead-through, the electrical and / or data line ends at the connection device, so that the connection device must be configured in such a way that it can guide the electrical and / or data through the wall. On the other side of the wall, the connection device can in turn be connected to the electrical and / or data line. The connection device preferably comprises at least one plug piece. The plug piece facilitates the connection of the electrical and / or data line. In addition, preferably at least one plug piece is provided on each side. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention and its advantages are described in more detail below with reference to the accompanying drawings. It shows:

[0026] Figure 1 a schematic representation of an electrochemical device according to the invention, and

[0027] Figure 2 Figure 1 An enlarged detail in the connection area of ​​an electrical and / or data line. DETAILED DESCRIPTION

[0028] exist Figure 1 The electrochemical device 1 according to the invention shown in FIG. 1 is an electrolysis device for producing hydrogen. The device 1 comprises at least one stack 2, which is accommodated in a first volume 4 of a housing 7, and components 3 for an electrical supply, which are accommodated in a second volume 5 of the housing 7. The two volumes 4, 5 are separated by a gastight wall 6. In the present case, the first volume 4 is also designed to be gastight.

[0029] exist Figure 1 The components 3 for electrical supply, which are not described in detail, may include rectifiers, transformers and / or other electrical or electronic components, such as contactors, switches, filters, etc. In an advantageous configuration of the device 1, the power provided in the volume 5 corresponds to the power required by at least one stack 2 in the volume 4, that is, the modularity of the volumes 4 and 5 is matched. Alternatively, it is also possible to supply power to multiple (for example, two) volumes 4 through the volume 5, or to supply power to one volume 4 through a combination of multiple volumes 5.

[0030] Figure 1 Not shown, but present, are means for reducing the pressure, by means of which the pressure p1 in the first volume 4 can be set lower than the pressure p2 in the second volume 5 .

[0031] Figure 1 The apparatus shown in FIG. 4 may also comprise further components required for the functioning of the electrolysis apparatus, such as water preparation means, fluid supply means and / or means for separating product gas from fluid water.

[0032] At least one stack 2 and the components 3 for the electrical supply are connected via at least one electrical and / or data line 8, wherein the electrical line can be designed particularly short, in particular, according to the invention. The electrical and / or data line 8 is interrupted by a connecting device 9, which is integrated into the wall 6 in a gas-tight manner. In the present case, two further connecting devices 9 are integrated into the wall 6, for example, which enable the connection of further electrical and / or data lines 8.

[0033] like Figure 2 As shown, the connection device 9 has a base plate 11 with a plug 10. The base plate 11 is located on the side of the wall 6 facing the first volume 4 and is fastened to the wall by means of a fastening device 12 (for example in the form of a screw). The plug 10 passes through the opening in the wall 6 so that it protrudes on the other side of the wall 6 and connects the electrical and / or data line 8. The other end of the plug 10 is accommodated in a connecting plate 13, which is integrated into the base plate 11 and is configured to accommodate another electrical and / or data line 8, wherein the accommodation portion can also be implemented as a plug. The connecting plate 13 can be made of metal, plastic or composite material to ensure the required airtightness.

Claims

1. A method for operating an electrochemical device (1), in particular an electrolysis device, comprising: at least one stack (2), in particular an electrolytic stack; and a component (3) for an electrical supply, wherein the stack (2) is accommodated separately from the component (3) for an electrical supply in a gas-tightly closed volume (4) filled with gas, in particular air and / or an inert gas, wherein, during operation of the electrochemical device (1), the pressure (p1) in the volume (4) and / or the pressure (p2) in the environment or in another volume (5) accommodating the component (3) for an electrical supply is set such that the pressure (p1) is less than the pressure (p2).

2. The method according to claim 1, It is characterized in that Gas is extracted from the volume (4) accommodating the at least one stack (2) for setting the pressure (p1).

3. The method according to claim 1 or 2, It is characterized in that The volume (5) accommodating the component (3) for the electrical supply is charged with gas, in particular air and / or an inert gas, in order to adjust the pressure (p2).

4. An electrochemical device (1), in particular an electrolytic device, comprising: at least one stack (2), in particular an electrolytic stack, which is accommodated in a first volume (4), which is filled with a gas, in particular with air and / or an inert gas, and - components (3) for the electrical supply, said components being accommodated in the second volume (5), Therein, two volumes (4, 5) are separated from one another in a gas-tight manner, wherein means are provided for reducing the pressure in the first volume (4) and / or means are provided for applying pressure to the second volume (5).

5. The electrochemical device (1) according to claim 4, It is characterized in that The first volume (4) and the second volume (5) are separated in a gas-tight manner by a wall (6) of an enclosure (7) in which at least the first volume (4) is constructed.

6. The electrochemical device (1) according to claim 5, It is characterized in that The wall (6) has at least one integrated wall leadthrough, which is designed to be gas-tight, for at least one electrical and / or data line (8).

7. The electrochemical device (1) according to claim 5 or 6, It is characterized in that The wall (6) has at least one integrated connection device (9) embodied in a gas-tight manner for at least one electrical and / or data line (8), wherein the connection device (9) preferably comprises at least one plug element (10).

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