Electrolyser

Abstract

The invention relates to an electrolyser (1) having a stack (2), an oxygen gas system (8) which is fluidically connected to anode-side regions, a hydrogen gas system (9) which is fluidically connected to cathode-side regions, an oxygen reservoir (14), a first oxygen connection conduit (16) which fluidically connects the oxygen gas system (8) to the oxygen reservoir (14), an oxygen-side shut-off element (10) which is disposed in the first oxygen connection conduit (16) and has a closed state and an open state, a hydrogen reservoir (15), a first hydrogen connection conduit (17) which fluidically connects the hydrogen gas system (9) to the hydrogen reservoir (15), a hydrogen-side shut-off element (11) which is disposed in the first hydrogen connection conduit (17) and has a closed state and an open state, and a control device (3) which is designed to bring the oxygen-side shut-off element (10) and the hydrogen-side shut-off element (11) simultaneously from the closed state to the open state on exceedance of a threshold value of a pressure differential between an anode-side gas and a cathode-side gas.

Description

[0001] 2024PF00308

[0002] Description

[0003] Electrolyzer

[0004] The invention relates to an electrolyzer.

[0005] An electrolyzer is set up to split water into hydrogen and oxygen through electrolysis. The electrolyzer comprises an electrochemical cell with a cathode and an anode, where the electrolysis can be described, for example, by the following reaction equations: Anode: 2 + H2O + 2 e~

[0006] Cathode: 2 H20 + 2 e~ -> H2+ 2 OH“ Total: H20 -> H2

[0007] As the equations show, both water and a gas are in contact with the cathode and the anode. During operation of the electrolyzer, a pressure difference can develop between the cathode and the anode. This can lead to the transfer of one gas into the other, resulting in a mixing of oxygen and hydrogen. This mixing creates an explosive mixture, which poses a safety risk to the electrolyzer. Furthermore, the pressure difference can damage the electrochemical cell, thus shortening its lifespan. This particularly affects the diaphragm, membrane, and / or gas diffusion layer of the electrochemical cell.

[0008] Therefore, one aim of the invention is to create an electrolyzer that has a long service life.

[0009] The electrolyzer according to the invention comprises a stack containing a plurality of electrochemical cells, each having an anode-side region and a cathode-side region. The electrolyzer has an oxygen gas system fluidly connected to the anode-side regions and a hydrogen gas system fluidly connected to the cathode-side regions. 2024PF00308

[0010] 2. Furthermore, the electrolyzer has an oxygen reservoir, a first oxygen connecting line that fluidly connects the oxygen gas system to the oxygen reservoir, and an oxygen soapy shut-off device located in the first oxygen connecting line. This shut-off device has a closed state in which the first oxygen connecting line is closed and an open state in which the first oxygen connecting line is open. The electrolyzer also has a hydrogen reservoir, a first hydrogen connecting line that fluidly connects the hydrogen gas system to the hydrogen reservoir, and a hydrogen soapy shut-off device located in the first hydrogen connecting line. This shut-off device has a closed state in which the first hydrogen connecting line is closed and an open state in which the first hydrogen connecting line is open.Furthermore, the electrolyzer has a control unit which is designed to simultaneously move the oxygen soapy shut-off device and the hydrogen soapy shut-off device from the closed state to the open state when a threshold value of a differential pressure is exceeded between an anode-side gas arranged in the oxygen system and a cathode-side gas arranged in the hydrogen gas system, or between the anode-side gas arranged in the anode-side areas and the cathode-side gas arranged in the cathode-side areas.

[0011] Exceeding the threshold can occur either when the pressure of the anode-side gas is higher than the pressure of the cathode-side gas, or when the pressure of the anode-side gas is lower than the pressure of the cathode-side gas. When the threshold is exceeded, the control unit opens both the oxygen-soapy shut-off valve and the hydrogen-soapy shut-off valve, allowing the anode-side gas to flow away from the anode-side areas via the oxygen gas system and via the first oxygen connection. 2024PF00308

[0012] 3. The oxygen reservoir and the cathode-side gas flow from the cathode-side sections via the hydrogen gas system and the first hydrogen connection line into the hydrogen reservoir. By simultaneously opening the oxygen-side shut-off valve and the hydrogen-side shut-off valve, the anode-side and cathode-side gases also flow out simultaneously, resulting in a simultaneous pressure drop in both the anode-side and cathode-side sections. This reduces the differential pressure between the anode-side and cathode-side sections, thus preventing damage to the electrolyzer and ensuring a long service life.

[0013] The differential pressure threshold depends strongly on the electrolyzer design. In particular, the threshold depends on the properties of the anode-side and cathode-side sections. For example, the threshold is preferably a maximum of 10 mbar, 2 bar, or 5 bar. This ensures that damage to the electrolyzer is particularly well prevented. Alternatively, the threshold is preferably at least 2 mbar, 1 bar, or 2 bar. This advantageously prevents the oxygen and hydrogen shut-off valves from opening unintentionally.

[0014] It is preferred that a gas pressure in the oxygen reservoir and / or a gas pressure in the hydrogen reservoir lies in a range that is from p atm -100 mbar to p atm lies, where p a tm is atmospheric pressure.

[0015] It is preferred that the electrolyzer has an oxygen blowing lance which is fluidly connected to the first oxygen connecting line, is arranged downstream of the first oxygen connecting line and is open to the atmosphere, whereby the oxygen reservoir is connected to the atmosphere. 2024PF00308

[0016] 4. The electrolyzer comprises a hydrogen blow-out lance, which is fluidly connected to the first hydrogen connection line, is arranged downstream of the first hydrogen connection line, and is open to the atmosphere, whereby the atmosphere constitutes the hydrogen reservoir. This advantageously represents a particularly simple device for designing the oxygen reservoir and / or the hydrogen reservoir. The hydrogen blow-out lance is preferably designed as a flare. This allows the hydrogen to be combusted upon entering the atmosphere, thereby preventing the formation of oxyhydrogen gas.

[0017] The oxygen reservoir preferably includes an oxygen intermediate storage tank, and / or the hydrogen reservoir preferably includes a hydrogen intermediate storage tank. The oxygen intermediate storage tank and / or the hydrogen intermediate storage tank compensate for the fact that processes on the anode side proceed at different rates than processes on the cathode side. Furthermore, the gases can be stored in the respective intermediate storage tanks for later use. The oxygen intermediate storage tank can, for example, include a piston storage tank, a diaphragm storage tank, a pressure storage tank, and / or a gasometer. The hydrogen intermediate storage tank can, for example, include a piston storage tank, a diaphragm storage tank, a pressure storage tank, and / or a gasometer.

[0018] The oxygen-soapy shut-off device and / or the hydrogen-side shut-off device are preferably selected from the group: ball valve, diaphragm valve, butterfly valve, rotary cone valve, three-way valve, quick-opening valve, safety valve and control valve.

[0019] The control device is preferably configured to supply the oxygen soapy shut-off device and the hydrogen soapy shut-off device with the same control signal, which controls the oxygen soapy shut-off device and the hydrogen soapy shut-off device. 2024PF00308

[0020] The 5-sided shut-off device is moved from the closed state to the open state. Alternatively or additionally, the oxygen-side shut-off device and the hydrogen-side shut-off device have the same actuator. Alternatively or additionally, the control device is configured to supply the oxygen-side shut-off device and the hydrogen-side shut-off device with the same control medium, which moves the oxygen-side shut-off device and the hydrogen-side shut-off device from the closed state to the open state. With all three of the aforementioned preferred embodiments, it can be ensured that the oxygen-side shut-off device and the hydrogen-side shut-off device are moved simultaneously from the closed state to the open state.

[0021] The electrolyzer is preferably configured such that a pressure reduction of the anode-side gas occurs in the anode-side areas when the oxygen-side shut-off device is moved from the closed state to the open state, and / or that a pressure reduction of the cathode-side gas occurs in the cathode-side areas when the hydrogen-side shut-off device is moved from the closed state to the open state.

[0022] It is preferred that the oxygen gas system includes an oxygen separator configured to separate the anode-side gas from water, wherein the first oxygen connection line opens directly into the oxygen separator or opens into the oxygen gas system downstream of the oxygen separator, and / or wherein the hydrogen gas system includes a hydrogen separator configured to separate the cathode-side gas from water, wherein the first hydrogen connection line opens directly into the hydrogen separator or opens into the hydrogen gas system downstream of the hydrogen separator. This ensures that no water or only a small amount of water enters the oxygen connection line and / or the hydrogen connection line. 2024PF00308

[0023] 6

[0024] It is preferred that the electrolyzer has a second oxygen connection line, which connects the oxygen system to the oxygen reservoir independently of the first oxygen connection line, and an oxygen soapy overpressure safety valve arranged in the second oxygen connection line, which has a closed state and an open state in which the maximum mass flow through the second oxygen connection line and the oxygen soapy overpressure safety valve is lower than the maximum mass flow through the first oxygen connection line and the oxygen soapy shut-off device in its open state, and / or wherein the electrolyzer has a second oxygen connection line, which connects the hydrogen gas system to the hydrogen reservoir independently of the first oxygen connection line, and a hydrogen soapy overpressure safety valve.The valve, located in the second hydrogen connection line, has a closed state and an open state in which the maximum mass flow through the second hydrogen connection line and the hydrogen-soapy pressure relief valve is lower than the maximum mass flow through the first hydrogen connection line and the hydrogen-side shut-off device in its open state. This ensures that if the oxygen-soapy pressure relief valve opens and / or the hydrogen-soapy pressure relief valve opens and the threshold is thereby exceeded, damage to the electrolyzer can be avoided.

[0025] The first oxygen connection line and the first oxygen-side shut-off device in its open state are preferably dimensioned such that a maximum mass flow rate of the anode-side gas produced during electrolysis can be discharged via the first oxygen connection line and / or the first hydrogen-side shut-off device in its open state are preferably dimensioned such that a maximum mass flow rate of the cathode-side gas produced during electrolysis 2024PF00308

[0026] 7. The water can be discharged via the first hydrogen connection line. This ensures that damage to the electrolyzer can be avoided particularly reliably.

[0027] It is preferred that the maximum oxygen flow rate that can pass through the open oxygen shut-off valve and the first oxygen connecting line is lower than the maximum hydrogen flow rate that can pass through the open hydrogen shut-off valve and the first hydrogen connecting line. This compensates for the fact that a higher hydrogen flow rate than oxygen flow rate is generated during electrolysis. This ensures that the pressure drop in the anode-side gas diffusion layers and the pressure drop in the cathode-side gas diffusion layers occur at a similar rate, resulting in a small differential pressure between the cathode-side and anode-side gas diffusion layers during these pressure drops.The electrolyzer may preferably have an orifice and / or a valve, which is particularly manually adjustable, arranged in the first oxygen connecting line and by means of which the maximum mass flow of the oxygen is limited.

[0028] The electrolyzer is preferably configured to supply water to the stack during operation, with the electrochemical cells being configured to split the water into oxygen and hydrogen by electrolysis during operation. It is conceivable that, during operation, water and oxygen are arranged in the anode-side regions and water and hydrogen are arranged in the cathode-side regions. The anode-side regions can, for example, be anode-side gas diffusion layers, and the cathode-side regions can, for example, be anode-side gas diffusion layers. 2024PF00308

[0029] 8

[0030] The invention will now be explained in more detail with reference to the accompanying schematic drawing. The figure shows a circuit diagram of an electrolyzer.

[0031] As can be seen from the figure, an electrolyzer 1 has a stack 2 comprising a plurality of electrochemical cells, each having an anode-side region and a cathode-side region. The electrolyzer 1 has an oxygen gas system 8, which is fluidly connected to the anode-side regions, and a hydrogen gas system 9, which is fluidly connected to the cathode-side regions. The electrolyzer 1 has an oxygen reservoir 14, a first oxygen connecting line 16, which fluidly connects the oxygen gas system 8 to the oxygen reservoir 14, and an oxygen shut-off device 10, which is arranged in the first oxygen connecting line 16, has a closed state in which the first oxygen connecting line 16 is closed, and an open state in which the first oxygen connecting line 16 is open.The electrolyzer has a hydrogen reservoir 15, a first hydrogen connecting line 17 which fluidly connects the hydrogen gas system 9 to the hydrogen reservoir 15, and a hydrogen-side shut-off device 11 which is arranged in the first hydrogen connecting line 17, has a closed state in which the first hydrogen connecting line 17 is closed, and has an open state in which the first hydrogen connecting line 17 is open.The electrolyzer 1 has a control unit 3 which is configured, when a pressure differential threshold is exceeded between an anode-side gas located in the oxygen system 8 and a cathode-side gas located in the hydrogen gas system 9, or between the anode-side gas located in the anode-side areas and the cathode-side gas located in the cathode-side areas, to simultaneously open the oxygen soapy shut-off device 10 and the hydrogen soapy shut-off device 11 from the closed state to the open state. The anode-side area can, for example, be an anode-side gas diffusion layer. The cathode-side area can, for example, be a cathode-side gas diffusion layer.

[0032] In this context, "simultaneous" can mean that the times at which the oxygen soapy shut-off device 10 and the hydrogen soapy shut-off device 11 enter the open state are no more than 200 ms apart, and in particular no more than 100 ms apart. The open state can, for example, describe the state in which the oxygen soapy shut-off device 10 or the hydrogen soapy shut-off device 11 is fully open.

[0033] The oxygen gas system 8 and the hydrogen gas system 9 can be designed in such a way that no gas can pass from the oxygen gas system 8 to the hydrogen gas system 9 and vice versa.

[0034] Electrolyzer 1 can be configured to supply water to stack 2 via a water line 4 during operation of electrolyzer 1. The electrochemical cells can be configured to split the water into oxygen and hydrogen through electrolysis during operation. The current required for electrolysis can be supplied to the stack via a power line 5. Thus, during operation, a flow of water from water line 4 to the anode-side areas and to the cathode-side areas results.

[0035] From the anode-side areas, the flow in the plant leads into the oxygen gas system 8. For this purpose, the oxygen gas system 8 can have an oxygen line 6, which is arranged downstream of the anode-side areas and upstream of the first oxygen connecting line 16. In addition, the oxygen gas system 8 can have an oxygen supply line 20, via which the anode-side gas is carried away from the electrolyzer 1 for further use in the plant and which is arranged downstream of the oxygen line 6. The 2024PF00308

[0036] The first oxygen connecting line 16 can open into the oxygen gas system 8 in a position located downstream of the oxygen line 6 and upstream of the oxygen supply line 20. If the system is operating correctly and the oxygen-side shut-off device 10 is in the closed position, it is conceivable that the entire mass flow of the anode-side gas is discharged via the oxygen supply line 20. If the system is malfunctioning and the oxygen shut-off device 10 is in its open position, it is conceivable that part or all of the mass flow of the anode-side gas is discharged via the first oxygen connecting line.

[0037] 16 is discharged into the oxygen reservoir 14.

[0038] From the cathode-side areas, the flow in the plant leads into the hydrogen gas system 9. For this purpose, the hydrogen gas system 9 can have a hydrogen line 7, which is arranged downstream of the cathode-side areas and upstream of the first hydrogen connecting line 17. In addition, the hydrogen gas system 9 can have a hydrogen supply line 21, via which the cathode-side gas is carried away from the electrolyzer 1 in the plant for further use and which is arranged downstream of the hydrogen line 7. The first hydrogen connecting line 17 can open into the hydrogen gas system 9 in a position that is arranged downstream of the hydrogen line 7 and upstream of the hydrogen supply line 21. If the operation is fault-free and thus the hydrogen-soapy shut-off device 11 is in the closed state, it is conceivable that the entire mass flow of the cathode-side gas is discharged via the hydrogen supply line 21.If the operation is faulty and thus the hydrogen soapy shut-off device 11 is in its open position, it is conceivable that part of the mass flow or the entire mass flow of the cathode-side gas via the first hydrogen connecting line.

[0039] 17 is discharged into the water reservoir 15.

[0040] The electrolyzer 1 can be configured such that a pressure reduction of the anode-side gas occurs in the anode-side areas when the oxygen soapy shut-off device 10 2024PF00308

[0041] 11 is brought from the closed state to the open state, and / or that a pressure release of the cathode-side gas occurs in the cathode-side areas when the hydrogen soapy shut-off device 11 is brought from the closed state to the open state.

[0042] The oxygen-soapy shut-off device 10 and / or the hydrogen-side shut-off device 11 can, for example, be selected from the following groups: ball valve, diaphragm valve, butterfly valve, rotary cone valve, three-way valve, quick-opening valve, safety valve, and control valve. The oxygen-soapy shut-off device 10 and / or the hydrogen-soapy shut-off device 11 can, for example, be fail-safe shut-off devices, in particular according to IEC 61508 or IEC 61511. The first oxygen connecting line 16 and the first oxygen-side shut-off device 10 in its open state can, for example, be dimensioned such that a maximum mass flow rate of the anode-side gas generated during electrolysis can be discharged via the first oxygen connecting line 16.The first hydrogen connecting line 17 and the first hydrogen soapy shut-off device 11 in its open state can, for example, be dimensioned such that a maximum mass flow of the cathode-side gas produced during electrolysis can be discharged via the first hydrogen connecting line 17.

[0043] A gas pressure in the oxygen reservoir 14 and / or a gas pressure in the hydrogen reservoir 15 can, for example, be in a range that is determined by p atm -100 mbar to p atm lies, where p a tm is atmospheric pressure. Atmospheric pressure can, in particular, be the pressure of the atmosphere currently acting on the outside of electrolyzer 1.

[0044] The electrolyzer 1 can have an oxygen blowing lance, which is fluidly connected to the first oxygen supply line 16, is arranged downstream of the first oxygen supply line 16 and is open to the atmosphere, whereby the oxygen reservoir 14 is the atmosphere. The 2024PF00308

[0045] 12

[0046] Electrolyzer 1 can have a hydrogen blow-off lance that is fluidly connected to the first hydrogen connecting line 17, is located downstream of the first hydrogen connecting line 17, and is open to the atmosphere, with the atmosphere being the hydrogen reservoir 15. The oxygen blow-off lance and the hydrogen blow-off lance can be spaced apart from each other. This prevents the formation of oxyhydrogen gas. In particular, the distance between the oxygen blow-off lance and the hydrogen blow-off lance is at least 1 m, at least 10 m, or at least 20 m. The hydrogen blow-off lance can, for example, be designed as a flare. Additionally or alternatively, it is conceivable that the oxygen reservoir 14 has an intermediate oxygen storage capacity and / or that the hydrogen reservoir 15 has an intermediate hydrogen storage capacity.

[0047] It is conceivable that the electrolyzer 1 has a second oxygen connecting line 18, which connects the oxygen gas system 8 to the oxygen reservoir 14 independently of the first oxygen connecting line 16 in a fluid-conducting manner, and an oxygen soapy overpressure safety valve 12, which is arranged in the second oxygen connecting line 18, has a closed state in which the second oxygen connecting line 18 is closed, and an open state in which the second oxygen connecting line 18 is open and the maximum mass flow through the second oxygen connecting line 18 and the oxygen soapy overpressure safety valve 12 is lower than the maximum mass flow through the first oxygen connecting line 16 and the oxygen soapy shut-off device 10 in its open state.Similarly, it is conceivable that the electrolyzer 1 has a second oxygen connecting line 18, which fluidly connects the hydrogen gas system 9 to the hydrogen reservoir 15 independently of the first hydrogen connecting line 17, and a hydrogen soapy overpressure safety valve 13, which is arranged in the second hydrogen connecting line 19, a closed state in which the second hydrogen connecting line 19 is closed, 2024PF00308.

[0048] 13 and has an open state in which the second hydrogen connecting line 19 is open and the maximum mass flow through the second hydrogen connecting line 19 and the hydrogen soapy overpressure safety valve 13 is lower than the maximum mass flow through the first hydrogen connecting line 17 and the hydrogen soapy shut-off device 11 in its open state.

[0049] It is conceivable that the oxygen gas system 8 includes an oxygen separator configured to separate the anode-side gas from the water, with the first oxygen connecting line 16 opening directly into the oxygen separator or opening into the oxygen gas system 8 downstream or upstream of the oxygen separator. The oxygen separator can be a container having a larger internal cross-section than the first oxygen connecting line 16 and, in particular, than the oxygen line 6 and the oxygen supply line 20. The oxygen separator can have a drain through which the water separated from the anode-side gas is discharged during operation.Similarly, the hydrogen gas system 9 can include a hydrogen separator configured to separate the cathode-side gas from water, wherein the first hydrogen connecting line 17 opens directly into the hydrogen separator or opens into the hydrogen gas system 9 downstream or upstream of the hydrogen separator. The hydrogen separator can be a container having a larger internal cross-section than the first hydrogen connecting line 17 and, in particular, than the hydrogen line 7 and the hydrogen supply line 21. The hydrogen separator can have a drain through which the water separated from the cathode-side gas is discharged during operation.

[0050] To compensate for the fact that a larger volume of cathode-side gas than anode-side gas is formed in the operation, a maximum oxygen-soapy volume flow rate can be achieved that can pass the oxygen-soapy shut-off device 10 in its open state and the first oxygen connecting line 16, 2024PF00308

[0051] 14 is lower than a maximum hydrogen-side volume flow that can pass through the soapy shut-off device 11 in its open state and the first hydrogen connecting line 17. For this purpose, the electrolyzer 1 can have an orifice and / or a valve, which is in particular manually adjustable, which are arranged in the first oxygen connecting line 16 and by means of which the maximum oxygen soapy volume flow is limited.

[0052] It is conceivable that electrolyzer 1 has an oxygen-soapy pressure sensor that is set up to measure a pressure p. Ato measure the anode-side gas, and has a hydrogen f soapy pressure sensor which is set up to measure a pressure p K to measure the gas on the cathode side. The differential pressure p D can be defined as follows: PD = IPA — PKI

[0053] The electrolyzer 1 can have an oxygen-soapy signal line 22, via which a signal with information about the pressure p is transmitted. A communication can be made from the oxygen-soapy pressure sensor to the control unit 3, and a hydrogen-soapy signal line 23 has a signal via which a signal with information about the pressure p can be transmitted. K Communication can take place from the hydrogen-based soapy pressure sensor to the control unit 3. It is conceivable that the oxygen-based soapy pressure sensor is configured to measure the pressure p. A to measure in the oxygen gas system 8, and that the hydrogen f soapy pressure sensor is set up to measure the pressure p Kto measure in the hydrogen gas system 9, as indicated in the figure. Alternatively, it is conceivable that the oxygen soapy pressure sensor is set up to measure the pressure p. A to measure in the anode-side areas, and that the hydrogen f soapy pressure sensor is set up to measure the pressure p K to measure in the cathode-side areas. Alternatively, instead of using the oxygen-soap pressure sensor and the hydrogen-soap pressure sensor, it is also conceivable to use a differential pressure sensor that measures the differential pressure PD. = IPA — PKI measures. For this purpose, an anode-side line can be provided, which fluidly connects the anode-side areas to the differential pressure sensor, and a cathode-side line can be provided, which connects the cathode-side areas. 2024PF00308

[0054] 15 areas are connected to the differential pressure sensor via a fluid-conducting mechanism.

[0055] As can be seen from the figure, the control device 3 can be configured to apply the same control signal to the oxygen soapy shut-off device 10 and the hydrogen soapy shut-off device 11, which moves the oxygen soapy shut-off device 10 and the hydrogen soapy shut-off device 11 from the closed state to the open state. The control signal can, for example, be an electrical control signal. For this purpose, the electrolyzer 1 can have a control line 24 that connects the control device 3 to the oxygen soapy shut-off device 10 and the hydrogen soapy shut-off device 11. Additionally or alternatively, it is conceivable that the oxygen soapy shut-off device 10 and the hydrogen soapy shut-off device 11 have the same actuator.The actuator could, for example, be an electromagnet capable of moving both the oxygen-soapy shut-off device 10 and the hydrogen-soapy shut-off device 11 from the closed to the open state. Alternatively or additionally, the control device 3 could be configured to supply the oxygen-soapy shut-off device 10 and the hydrogen-soapy shut-off device 11 with the same control medium, which moves both the oxygen-soapy shut-off device 10 and the hydrogen-soapy shut-off device 11 from the closed to the open state. The control medium could, for example, be air, particularly compressed air. The oxygen-soapy shut-off device 10 and the hydrogen-soapy shut-off device 11 could, for example, each be held in the closed state against a preload by the control medium.In the event of a pressure drop in the control medium, the oxygen soapy shut-off device 10 and the hydrogen soapy shut-off device 11 can move from the closed state to the open state.

Claims

2024PF00308 16 Patentansprüche 1. Electrolyzer with a stack (2) comprising a plurality of electrochemical cells, each having an anode-side region and a cathode-side region, an oxygen gas system (8) fluidly connected to the anode-side regions, a hydrogen gas system (9) fluidly connected to the cathode-side regions, an oxygen reservoir (14), a first oxygen connecting line (16) fluidly connecting the oxygen gas system (8) to the oxygen reservoir (14), an oxygen soapy shut-off device (10) arranged in the first oxygen connecting line (16), which has a closed state in which the first oxygen connecting line (16) is closed and an open state in which the first oxygen connecting line (16) is open, a hydrogen reservoir (15), a first hydrogen connecting line (17),which fluidly connects the hydrogen gas system (9) to the hydrogen reservoir (15), a hydrogen soapy shut-off device (11) which is arranged in the first hydrogen connecting line (17), which has a closed state in which the first hydrogen connecting line (17) is closed, and an open state in which the first hydrogen connecting line (17) is open, and a control device (3) which is configured to, when a threshold value of a differential pressure is exceeded between an anode-side gas which is arranged in the oxygen system (8) and a cathode-side gas which is arranged in the hydrogen gas system (9), or between the anode-side gas which is arranged in the anode-side areas and the cathode-side gas which is arranged in cathode-side areas,to simultaneously move the oxygen-side shut-off device (10) and the hydrogen-soapy shut-off device (11) from the closed state to the open state.

2. Electrolyzer according to claim 1, wherein a gas pressure in the oxygen reservoir (14) and / or a gas pressure in the 2024PF00308 17 hydrogen reservoir (15) lies in a range from Patm- 100 mbar to p a tm lies, where p a tm the atmospheric pressure is .

3. Electrolyzer according to claim 1 or 2, wherein the electrolyzer (1) has an oxygen blow-out lance which is fluidly connected to the first oxygen connecting line (16), is arranged downstream of the first oxygen connecting line (16) and is open to the atmosphere, wherein the oxygen reservoir (14) is the atmosphere, and / or wherein the electrolyzer (1) has a hydrogen blow-out lance which is fluidly connected to the first hydrogen connecting line (17), is arranged downstream of the first hydrogen connecting line (17) and is open to the atmosphere, wherein the hydrogen reservoir (15) is the atmosphere.

4. Electrolyzer according to claim 3, wherein the hydrogen blow-out lance is designed as a torch.

5. Electrolyzer according to any one of claims 1 to 4, wherein the oxygen reservoir (14) has an oxygen intermediate storage and / or wherein the hydrogen reservoir (15) has a hydrogen intermediate storage.

6. Electrolyzer according to any one of claims 1 to 5, wherein the oxygen-side shut-off device (10) and / or the hydrogen-side shut-off device (11) are selected from the group consisting of: ball valve, diaphragm valve, butterfly valve, rotary cone valve, three-way valve, quick-opening valve, safety valve and control valve.

7. Electrolyzer according to any one of claims 1 to 6, wherein the control device (3) is configured, the oxygen soapy shut-off device (10) and the hydrogen soapy shut-off device are configured. (11) to apply the same control signal, which opens the oxygen-side shut-off device (10) and the hydrogen-side shut-off device (11) from the closed state to the 2024PF00308 18 brings to an open state, and / or wherein the oxygen soapy shut-off device (10) and the hydrogen soapy shut-off device (11) have the same actuator, and / or wherein the control device (3) is configured to open the oxygen soapy shut-off device. (10) and the hydrogen soapy shut-off device (11) with the same control medium that the oxygen soapy shut-off device (10) and the hydrogen soapy shut-off device (11) from the closed state to the open state.

8. Electrolyzer according to any one of claims 1 to 7, wherein the electrolyzer (1) is configured such that a pressure reduction of the anode-side gas occurs in the anode-side areas when the oxygen soapy shut-off device (10) is moved from the closed state to the open state, and / or that a pressure reduction of the cathode-side gas occurs in the cathode-side areas when the hydrogen soapy shut-off device (11) is moved from the closed state to the open state.

9. Electrolyzer according to any one of claims 1 to 8, wherein the oxygen gas system (8) comprises an oxygen separator configured to separate the anode-side gas from water, wherein the first oxygen connecting line (16) opens directly into the oxygen separator or downstream or upstream of the oxygen separator into the oxygen gas system (8) and / or wherein the hydrogen gas system (9) comprises a hydrogen separator configured to separate the cathode-side gas from water, wherein the first hydrogen connecting line (17) opens directly into the hydrogen separator or downstream or upstream of the hydrogen separator into the hydrogen gas system (9).

10. Electrolyzer according to any one of claims 1 to 9, wherein the electrolyzer (1) has a second oxygen connecting line (18) which fluidly connects the oxygen gas system (8) to the oxygen reservoir (14) independently of the first oxygen connecting line (16), and an oxygen soapy overpressure safety valve (12) which is located in the 2024PF00308 19 second oxygen connecting line (18) is arranged, has a closed state and an open state in which the maximum mass flow through the second oxygen connecting line (18) and the oxygen soapy overpressure safety valve (12) is lower than the maximum mass flow through the first oxygen connecting line (16) and the oxygen-side shut-off device (10) in its open state, and / or wherein the electrolyzer (1) has a second oxygen connecting line (18) which fluidly connects the hydrogen gas system (9) independently of the first hydrogen connecting line (17) to the hydrogen reservoir (15), and a hydrogen soapy overpressure safety valve (13) which is arranged in the second hydrogen connecting line (19), has a closed state and an open state,in which the maximum mass flow through the second hydrogen connecting line (19) and the hydrogen soapy overpressure safety valve (13) is lower than the maximum mass flow through the first hydrogen connecting line (17) and the hydrogen soapy shut-off device (11) in its open state.

11. Electrolyzer according to any one of claims 1 to 10, wherein the first oxygen connecting line (16) and the first oxygen soapy shut-off device (10) are dimensioned in its open state such that a maximum mass flow of the anode-side gas produced during electrolysis can be discharged via the first oxygen connecting line (16) and / or wherein the first hydrogen connecting line (17) and the first hydrogen soapy shut-off device (11) are dimensioned in its open state such that a maximum mass flow of the cathode-side gas produced during electrolysis can be discharged via the first hydrogen connecting line (17).

12. Electrolyzer according to one of claims 1 to 11, wherein an oxygen-soapy maximum volume flow that can pass the oxygen-side shut-off device (10) in its open state and the first oxygen connecting line (16) is low- 2024PF00308 20 is greater than a hydrogen-side maximum volume flow that can pass the hydrogen soapy shut-off device (11) in its open state and the first hydrogen connecting line (17).

13. Electrolyzer according to claim 12, wherein the electrolyzer (1) has an orifice and / or a valve, which is in particular manually adjustable, which are arranged in the first oxygen connecting line (16) and by means of which the maximum volume flow of the oxygen is limited.

14. Electrolyzer according to any one of claims 1 to 13, wherein the electrolyzer (1) is configured to supply water to the stack (2) during operation of the electrolyzer (1), wherein the electrochemical cells are configured to split the water into oxygen and hydrogen by electrolysis during operation.

15. Electrolyzer according to claim 14, wherein in the operation water and oxygen are arranged in the anode-side areas and water and hydrogen are arranged in the cathode-side areas.

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