Method of operating an electrolysis system and electrolysis system

Abstract

The invention presented relates to a method (100) for operating an electrolysis system (200). The method (100) comprises: - operating (101) the electrolysis system (200) at an operating point at which a cathode pressure in a cathode chamber (203) of the electrolysis system (200) is greater than an anode pressure in an anode chamber (205) of the electrolysis system (200), - determining (103) an opening state of all safety valves (207a, 207b, 207c) of the electrolysis system (200) in a predefined time period and - outputting (105) a warning message in the event that the opening state of at least one of the safety valves (207a, 207b, 207c) changes multiple times in the predefined time period or all safety valves (207a, 207b, 207c) are in an open state in the predefined time period.

Description

[0001] R.416512

[0002] - 1 -

[0003] Description

[0004] title

[0005] Methods for operating an electrolysis system and electrolysis system

[0006] The presented invention relates to a method for operating an electrolysis system, an electrolysis system for converting energy and a program product according to the preambles of the independent claims.

[0007] State of the art

[0008] The core component of every electrolysis plant is the electrolysis cell stack, in which several electrolysis cells are stacked on top of each other. Within these electrolysis cells, the electrochemical splitting of water into hydrogen and oxygen takes place.

[0009] In electrolysis cells with a membrane, such as a proton exchange membrane (PEM) or an anion exchange membrane (AEM), the membrane separates the two reaction spaces on the anode side and cathode side from each other in order to spatially separate the two products hydrogen and oxygen.

[0010] If a membrane defect occurs in an electrolysis cell, such as a membrane tear or a hole, the separation of hydrogen and oxygen is no longer guaranteed, and a dangerous explosive mixture can form.

[0011] To increase the safety of an electrolysis plant, a membrane failure must be prevented, detected, and / or contained. R.416512

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[0013] Disclosure of the invention

[0014] Within the scope of the presented invention, a method for operating an electrolysis system, an electrolysis system for converting energy, and a program product according to the independent claims are presented. Further features and details of the invention will become apparent from the respective dependent claims, the description, and the drawings. Features and details described in connection with the electrolysis system according to the invention naturally also apply in connection with the method and the program product according to the invention, and vice versa, so that the disclosure of the individual aspects of the invention is always, or can always be, mutually referenced.

[0015] The invention presented here serves in particular to provide a means for the safe operation of an electrolysis system.

[0016] Thus, according to a first aspect of the presented invention, a method for operating an electrolysis system is presented.

[0017] The presented method comprises operating the electrolysis system at an operating point where the cathode pressure in a cathode compartment of the electrolysis system is greater than the anode pressure in an anode compartment of the electrolysis system, determining the opening state of all safety valves of the electrolysis system within a specified period, and issuing a warning message if the opening state of at least one of the safety valves changes multiple times within the specified period or if all safety valves are in an open state within the specified period.

[0018] In the context of the presented invention, issuing a warning message is understood to mean a process in which the warning message is displayed on an output unit, such as a display, and / or the warning message is transferred to a memory, in particular an error memory, and / or the warning message is sent to a target function, such as a function for controlling the R.416512

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[0020] electrolysis system, in particular a shut-off valve of the electrolysis system.

[0021] The presented invention is based on the detection of a faulty condition of an electrolysis system, such as a membrane tear or a membrane hole, by means of abnormal behavior of safety valves, i.e., so-called pressure release valves (PRV) in the anode and cathode compartment or corresponding lines of the electrolysis system.

[0022] Abnormal behavior of the safety valves can include, for example, repeated opening and closing at short intervals, repeated opening and closing at shorter intervals than would be expected in a selected operating mode, simultaneous opening of all safety valves, or brief opening and closing of the safety valves on the cathode side followed by the opening of a safety valve on the anode side.

[0023] In the event that a faulty condition is detected, or the opening state of at least one of the safety valves changes several times within the specified period, or all safety valves are in an open state within the specified period, a warning message is to be issued.

[0024] Accordingly, the procedure may include issuing a warning message in the event that the opening state of a safety valve in the cathode compartment changes several times within the specified period and subsequently a safety valve in the anode compartment is in its open state.

[0025] It may also be provided that the warning message includes a control command that causes an immediate stop to hydrogen production by the electrolysis system. R.416512

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[0027] A control command that causes an immediate stop to hydrogen production by the electrolysis system can, for example, include activating an emergency shutdown function in a control unit of the electrolysis system. It can also be provided that the warning message includes a control command that moves at least one anode shut-off valve to a position in which the at least one anode shut-off valve seals off the anode chamber, or that the warning message includes a control command that moves at least one changeover valve to a position in which the changeover valve directs a purge medium into the anode chamber.

[0028] By sealing off the anode compartment, hydrogen production by the electrolysis system is quickly and safely stopped, or the electrolysis system is deactivated.

[0029] By flushing the anode chamber with a flushing medium, such as water, any hydrogen accumulated in the anode chamber is diluted, minimizing the risk of forming an ignitable mixture. For this purpose, a switching valve, such as a 3-way valve, which is fluid-conducting between the anode chamber and a water tank, can be moved to a position that fluidly connects the water tank to the anode chamber.

[0030] It may also be provided that the specified period is determined based on a reference behavior during operation of the electrolysis system under specified reference conditions.

[0031] In order to dynamically optimize the specified period for a given electrolysis system, the period can be determined based on a reference behavior during operation of the electrolysis system under specified reference conditions, such as during initial commissioning or maintenance.

[0032] A time period determined based on a reference behavior ensures that the behavior of the respective safety valves, according to the reference behavior, does not trigger a warning message. This means that the probability of a false positive response is minimized. R.416512

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[0034] It may also be provided that the condition of at least one safety valve is determined by means of at least one proximity sensor.

[0035] A proximity sensor can detect the movement of the spring and / or the closing cone of a safety valve, thus reliably determining whether the safety valve has opened.

[0036] It can be provided that the proximity sensor transmits a control command directly to at least one anode shut-off valve as a warning message, wherein the control command moves the at least one anode shut-off valve into a position in which the at least one anode shut-off valve shuts off the anode chamber.

[0037] Direct control of the anode shut-off valve by a proximity sensor enables a particularly fast response to a faulty condition of the electrolysis system.

[0038] Optionally, the proximity sensor can also transmit a warning message to a control unit of the electrolysis system, for example to activate an emergency function to shut down the electrolysis system.

[0039] Alternatively, the proximity sensor can be communicatively coupled to a control unit, such as a safety control unit of the electrolysis system, so that the control unit evaluates values ​​or states provided by the proximity sensor, which can be a proximity switch, for example, and issues a warning message accordingly, in order to close the anode shut-off valve and / or activate an emergency function to shut down the electrolysis system.

[0040] The electrolysis system includes safety valves designed for pressure relief to protect the system from impermissible pressure overshoots. The safety valves are set to a predefined release pressure and open once this pressure is reached or exceeded. The release pressure differs depending on the specific anode R.416512.

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[0042] and cathode. The release pressure is set by means of a spring in the safety valve. The spring is positioned in the spring housing along a spindle and presses the closing cone against the seal of the valve seat via a guide plate.

[0043] According to a second aspect, the presented invention relates to an electrolysis system for converting energy.

[0044] The presented electrolysis system comprises an electrolysis cell stack, a cathode compartment, an anode compartment, a number of safety valves, a number of sensors for detecting the opening state of all safety valves of the electrolysis system, and a computing unit, wherein the computing unit is configured to execute a possible embodiment of the presented method.

[0045] In the context of the presented invention, a computing unit is understood to be a computer, in particular a cloud computer, a processor, a control unit or any other programmable circuit.

[0046] The computing unit may be configured to operate the electrolysis system at an operating point where the cathode pressure in the cathode chamber is greater than the anode pressure in the anode chamber, to determine the opening state of all safety valves of the electrolysis system within a specified period, and to issue a warning message if the opening state of at least one of the safety valves changes multiple times within the specified period or if all safety valves are in an open state within the specified period.

[0047] It may also be provided that the electrolysis system is a proton exchange membrane or an anion exchange membrane electrolysis system.

[0048] According to a third aspect, the presented invention relates to a program product, wherein the program product comprises program code means which, when the program product is executed on a computing unit,

[0049] - 7 -

[0050] Configure the computing unit to execute one possible implementation of the presented procedure.

[0051] Advantages described in detail for the method of operating an electrolysis system according to the first aspect of the invention apply equally to the electrolysis system according to the second aspect of the presented invention and to the program product according to the third aspect of the presented invention, and vice versa.

[0052] Further advantages, features, and details of the presented invention will become apparent from the following description, in which exemplary embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description can each be essential to the invention individually or in any combination.

[0053] They each show schematically:

[0054] Figure 1 shows a possible embodiment of the presented method,

[0055] Figure 2 shows a possible embodiment of the presented electrolysis system and

[0056] Figure 3 shows another possible embodiment of the presented electrolysis system.

[0057] Fig. 1 shows a method 100 for operating an electrolysis system 200 as shown, for example, in Fig. 2 or Fig. 3.

[0058] The process 100 comprises an operating step 101 in which the electrolysis system 200 is operated at an operating point in which a cathode pressure in a cathode chamber 203 of the electrolysis system 200 is greater than an anode pressure in an anode chamber 205 of the electrolysis system 200.R.416512

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[0060] Furthermore, the procedure 100 comprises a determination step 103, in which the opening state of all safety valves 207a, 207b, 207c of the electrolysis system 200 is determined within a specified period, and an output step 105, in which a warning message is issued if the opening state of at least one of the

[0061] Safety valves 207a, 207b, 207c change multiple times within the specified period or all safety valves 207a, 207b, 207c are in an open state within the specified period.

[0062] Figure 2 shows an electrolysis system 200 for converting energy, in particular for the electrolysis of water.

[0063] The electrolysis system 200 comprised an electrolysis cell stack 201, a cathode compartment 203, an anode compartment 205, a number of safety valves 207a, 207b, 207c, a number of sensors 209, such as proximity sensors, for detecting an opening state of all safety valves 207a, 207b, 207c of the electrolysis system 200 and a computing unit 211, wherein the computing unit 211 is configured to execute the method 100 according to Fig. 1.

[0064] In Fig. 2 the electrolysis system 200 is shown in a configuration in which a first safety valve 207a and a switching valve 213 are arranged at the anode outlet 215 of the anode chamber 205.

[0065] The switching valve 213 regulates a mass flow of water mixed with oxygen from the anode chamber 205 towards

[0066] Gas-liquid separator, as indicated by arrow 217.

[0067] The anode chamber 205 is supplied with fresh water from a freshwater source, as indicated by arrow 219.

[0068] A mass flow of water and hydrogen flows out of the cathode chamber 203, as indicated by arrow 221. R.416512

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[0070] The switching valve 213 is controlled by the computing unit 211, which receives and evaluates signals from the safety valves 207a, 207b, 207c or the respective sensors 209 arranged on the safety valves 207a, 207b, 207c.

[0071] In Fig. 3 the electrolysis system 200 is shown in a configuration in which the control of the safety valve 207a is carried out directly by the sensors 209.

[0072] Furthermore, the computing unit 211 is communicatively coupled with the electrolysis cell stack 201 in order to switch it off, for example, by means of an emergency function.

Claims

R.416512 - 10 - Claims 1. Method (100) for operating an electrolysis system (200), the method comprising: Operating (101) the electrolysis system (200) at an operating point where a cathode pressure in a cathode compartment (203) of the electrolysis system (200) is greater than an anode pressure in an anode compartment (205) of the electrolysis system (200), Determine (103) the opening state of all safety valves (207a, 207b, 207c) of the electrolysis system (200) within a specified period and Issue (105) a warning message if the opening state of at least one of the safety valves (207a, 207b, 207c) change several times within the specified period or all Safety valves (207a, 207b, 207c) are in an open state during the specified period.

2. Method (100) according to claim 1, characterized by that the procedure (100) continues to include: Issuing the warning message (107) in the event that the opening state of a safety valve (207b, 207c) in the cathode compartment (203) changes several times within the specified period and afterwards a safety valve (207a) in the anode compartment (205) is in its open state.

3. Method (100) according to claim 1 or 2, characterized by that the warning message includes a control command that causes an immediate stop to hydrogen production by the electrolysis system (200). R.416512 - 11 - 4. Method (100) according to one of the preceding claims, characterized in that that the warning message includes a control command that moves at least one anode shut-off valve to a position in which the at least one anode shut-off valve shuts off the anode chamber (205) or the warning message includes a control command that moves at least one changeover valve (213) to a position in which the changeover valve (213) directs a rinsing medium into the anode chamber (205).

5. Method (100) according to one of the preceding claims, characterized in that that the specified period is determined based on a reference behavior during operation of the electrolysis system (200) under specified reference conditions.

6. Method (100) according to one of the preceding claims, characterized in that that the condition of at least one The safety valve (207a, 207b, 207c) is determined by means of at least one proximity sensor (209).

7. Method (100) according to claim 6, characterized by that the proximity sensor (209) transmits a control command directly to at least one anode shut-off valve as a warning message, wherein the control command moves the at least one anode shut-off valve into a position in which the at least one anode shut-off valve shuts off the anode chamber (205). R.416512 - 12 - 8. Electrolysis system (200) for converting energy, the electrolysis system (200) comprises: an electrolysis cell stack (201), a cathode space (203), an anode space (205), a number of safety valves (207a, 207b, 207c), a number of sensors (209) for detecting the opening state of all safety valves (207a, 207b, 207c) of the electrolysis system (200) and a computing unit (211), wherein the computing unit (211) is configured to execute a method (100) according to any one of claims 1 to 7.

9. Electrolysis system (200) according to claim 8, characterized by that the computing unit (211) is configured for this purpose: to operate the electrolysis system (200) at an operating point where the cathode pressure in the cathode compartment (203) is greater than the anode pressure in the anode compartment (205), an open state of all to determine the safety valves (207a, 207b, 207c) of the electrolysis system (200) within a specified period and to issue a warning message if the opening state is at least one of the safety valves (207a, 207b, 207c) change several times within the specified period or all Safety valves (207a, 207b, 207c) are in an open state during the specified period.

10. Electrolysis system (200) according to claim 8 or 9, characterized by that the electrolysis system (200) is a proton exchange membrane or an anion exchange membrane electrolysis system. R.416512 - 13 - 11. Program product, wherein the program product comprises program code means which, when the program product is executed on a computing unit, configure the computing unit to execute a method (100) according to any one of claims 1 to 7.

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