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DE-102025119137-B3 - Device for the mechanical conditioning of PEM stacks and associated conditioning method

DE102025119137B3DE 102025119137 B3DE102025119137 B3DE 102025119137B3DE-102025119137-B3

Abstract

The present invention relates to a device (1) for mechanically conditioning PEM stacks (S) having an anode chamber and a cathode chamber respectively. The device (1) comprises a hot water supply (2V), a cold water supply (4V), a mixed water return (8), at least two stack receptacles (7), each suitable for receiving a PEM stack (S) to be conditioned, comprising a stack inlet (16) through which mixed water can be supplied to the anode chamber and/or the cathode chamber, and a stack outlet (17) through which the mixed water from the anode chamber and/or the cathode chamber can be discharged via the mixed water return (8), and at least two adjustable mixing valves (6), each assigned to a stack receptacle (7), with a hot water inlet (6H) fluidically connected to the hot water supply (2V), a cold water inlet (6K) fluidically connected to the cold water supply (4V), and a mixed water outlet (6M) fluidically connected to the stack inlet (16) of the associated stack receptacle (7). The mixed water from hot water and cold water, as set according to the respective mixing valve (6M), can be supplied to the stack inlet (16) of the associated stack receptacle (7) via the mixed water outlets (6M) of the mixing valves.

Inventors

  • Thomas Pursche
  • Jennifer Wegner
  • John Marten Boljen
  • Norbert Bülow

Assignees

  • QUEST ONE GMBH

Dates

Publication Date
20260513
Application Date
20250516

Claims (20)

  1. Device (1) for the mechanical conditioning of PEM stacks (S) each having an anode chamber and a cathode chamber, comprising: - a hot water supply (2V), - a cold water supply (4V), - a mixed water return (8), - at least one, preferably two or more, stack receptacles (7), each suitable for receiving a PEM stack (S) to be conditioned, comprising a stack inlet (16) through which mixed water can be supplied to the anode chamber and/or the cathode chamber, and a stack outlet (17) through which the mixed water from the anode chamber and/or the cathode chamber can be discharged via the mixed water return (8), and - at least two adjustable mixing valves (6), each assigned to a stack receptacle (7), with a hot water inlet (6H) fluidically connected to the hot water supply (2V) and a cold water supply (4V) fluidically connected to the cold water supply (4V). connected cold water inlet (6K) and a mixed water outlet (6M) fluidically connected to the stack inlet (16) of the associated stack receptacle (7), via which the mixed water of hot water and cold water mixed according to the setting of the respective mixing valve (6) can be made available at the stack inlet (16) of the associated stack receptacle (7).
  2. Device (1) according to Claim 1 , comprising - at least two inlet temperature sensors (18), each assigned to a stack inlet (7) and arranged in the respective stack inlet (16) and suitable for detecting the actual inlet temperature of the flowing mixed water, and - a control unit (11) operatively connected to the inlet temperature sensors (18) and the mixing valves (6), wherein - a corresponding target inlet temperature of the mixed water can be stored in the control unit (11) for each stack inlet (7), and - the control unit (11) is configured to control the mixing valves (6) based on the actual inlet temperatures detected by the inlet temperature sensors (18) such that the actual inlet temperature of the mixed water flowing through the respective stack inlet (16) corresponds to the corresponding stored target inlet temperature approximates.
  3. Device (1) according to one of the preceding claims, comprising: - at least two inlet conductance sensors, each arranged in one of the stack inlets (16) and suitable for detecting an actual inlet conductance; and/or: - at least two outlet conductance sensors (22), each arranged in one of the stack outlets (17) and suitable for detecting an actual outlet conductance; and: - at least two controllable shut-off valves (24), each arranged in one of the stack inlets (16) and/or one of the stack outlets (17) and suitable for shutting off the mixed water flow through the associated stack inlet (16) and/or stack outlet (17), wherein: - the inlet conductance sensors and the outlet conductance sensors (22) and the shut-off valves (24) are operatively connected to the control unit (11); - the control unit (11) is suitable for is to receive the actual inlet conductivity values and/or the actual outlet conductivity values and is designed to control the associated shut-off valve (24) in such a way that the mixed water flow through the associated stack inlet (16) and/or stack outlet (17) is shut off when a maximum conductivity value is exceeded by one of the actual inlet conductivity values and/or one of the actual outlet conductivity values.
  4. Device (1) according to one of the preceding claims, comprising - a hot water tank (3) fluidically connected to the hot water supply (2V) for providing hot water, and - a cold water tank (5) fluidically connected to the cold water supply (4V) for providing cold water, wherein - the mixed water return (8) is fluidically connected to the hot water tank (3) and/or the cold water tank (5) and optionally - the hot water tank (3) and/or the cold water tank (5) have a vent valve.
  5. Device (1) according to one of the preceding claims, comprising a stratified water storage tank (30) fluidically connected to the hot water supply (2V), the cold water supply (4V) and the mixed water return (8).
  6. Device (1) according to one of the preceding claims, comprising - at least one pump arranged in the hot water supply (2V) and/or in the cold water supply (4V). (12, 15), and/or - a flow heater device (13) arranged in the hot water supply (2V), and/or - a heating device (14) arranged in the hot water tank (3).
  7. Device (1) according to one of the Claims 4 until 6 , wherein the hot water tank (3) and the cold water tank (5) or the layered water storage tank (30) are arranged geodetically below the stack outlets (17) and/or below the stack inlets (16) of the stack receivings (7).
  8. Device (1) according to one of the preceding claims, wherein - the hot water supply (2V) and a hot water return (2R) form a hot water circuit (2), and - the cold water supply (4V) and a cold water return (4R) form a cold water circuit (4), and in particular - the device (1) has a heat exchanger (30) between the hot water return (2R) and the cold water supply (4V).
  9. Device (1) according to one of the preceding claims, comprising at least two throttle devices (19) each arranged in one of the stack inlets (16).
  10. Device (1) according to one of the preceding claims, comprising: - a hot water bypass (26) fluidically connecting the hot water supply (2V) to the mixed water return (8) with a hot water bypass valve (27); and - a cold water bypass (28) fluidically connecting the cold water supply (4V) to the mixed water return (8) with a cold water bypass valve (29), wherein: - the bypass valves (27, 29) are operatively connected to the control unit (11); and - the control unit (11) is configured to actuate the bypass valves (27, 29) such that, if the maximum conductivity is exceeded by one of the actual inlet conductivity values and/or one of the actual outlet conductivity values, hot water from the hot water supply (2V) flows through the hot water bypass (26) into the mixed water return (8), and cold water from the cold water supply (4V) can be pumped through the cold water bypass (28) into the mixed water return (8).
  11. Device (1) according to one of the preceding claims, wherein - the stack inlets (16) and the stack outlets (17) each comprise a coupling plate (20), and - the stack receptacles (7) have actuators (21) which are each assigned to one of the coupling plates (20) and are configured to move the coupling plates (20) into a pressed-in position and a lifted-off position, wherein in the pressed-in position a fluidically tight connection is established between the respective PEM stack (S) and the stack inlet (16) and the stack outlet of the associated stack receptacle.
  12. Device (1) according Claim 11 , wherein the coupling plates (20) and the at least one actuator (21) of a stack receptacle (7) each form a clamping device by means of which a clamping force, which can be varied in time, can be applied to the PEM stack (S) that is received.
  13. Device (1) according to one of the preceding claims, wherein - the stack inlets (16) each have a pressure fluctuation device configured to apply a water pressure fluctuation to the mixed water that can be supplied to the anode chamber and/or the cathode chamber of the associated PEM stack (S) via the respective stack inlet (16), and - the pressure fluctuation devices in particular each have a compression piston and a compression volume fluidically connected to the mixed water outlet (6M) of the associated mixing valve (6), and the size of the compression volume is variable by means of the compression piston.
  14. Device (1) according Claim 13 , wherein the stack inlets (16) each have an anode shut-off valve which is arranged downstream of the respective pressure fluctuation device and by which, in the closed state, the supply of mixed water through the stack inlet (16) into the anode chamber of the associated PEM stack can be prevented.
  15. Device (1) according to one of the preceding claims comprising - a water treatment device (9) arranged in particular in the mixed water return (8) for filtering impurities from the mixed water, and - optionally a water treatment bypass (10).
  16. Device (1) according to one of the preceding claims, wherein the stack inlets (16) are arranged geodetically below the stack outlets (17).
  17. Method (100) for mechanically conditioning PEM stacks (S) each having an anode chamber and a cathode chamber by means of a device (1) for mechanical conditioning according to one of the Claims 2 until 15 with the following steps: - Providing (110) the PEM stacks (S) to be conditioned in the device (1) for mechanical conditioning, wherein the PEM stacks (S) are each held in a stack receptacle (7) and a mixed water can be supplied to the anode chamber and/or the cathode chamber via a stack inlet (16) and the mixed water can be discharged from the anode chamber and/or the cathode chamber via a stack outlet (17), - Storing (120) target inlet temperatures of the mixed water for the stack receptacles (7) in the control unit (11), - Detecting (130) actual inlet temperatures of the mixed water flowing through the stack receptacles (7) by the inlet temperature sensors (18) and transmitting the actual inlet temperatures to the control unit (11), and - Actuating (140) the mixing valves (6) by the control unit (11) in such a way that the actual inlet temperature of the mixed water flowing through the respective stack inlet (16) approaches the corresponding stored target inlet temperature.
  18. Procedure (100) according to Claim 17 with the following steps: - Storing (125) time-dependent target inlet temperature profiles for the stack inlets (7) in the control unit (11), and - Controlling (145) the mixing valves (6) by the control unit (11) in such a way that the actual inlet temperature of the mixed water flowing through the respective stack inlet (16) approaches the corresponding stored target inlet temperature according to the corresponding time-dependent target inlet temperature profile.
  19. Procedure (100) according to Claim 17 or 18 with the following steps: - storing (150) a maximum conductivity value in the control unit (11), - detecting (160) actual inlet conductivity values and/or actual outlet conductivity values of the mixed water flowing through the stack inlets (7) by means of inlet conductivity sensors and/or outlet conductivity sensors (22) and transmitting the actual conductivity values to the control unit (11), and - when the control unit (11) detects an exceedance of the maximum conductivity value by one of the actual conductivity values, actuating (170) a shut-off valve (24) by the control unit (11) such that the mixed water flow through the associated stack inlet (16) and/or stack outlet (17) is shut off.
  20. Procedure (100) according to one of the Claims 17 until 19 with the following steps: - Storing (180) time-varying clamping force profiles for the stack receptacles (7) in the control unit (11), and - Applying (190) clamping forces, in particular time-varying forces, to the PEM stacks (S) according to the stored clamping force profiles by means of clamping devices, and/or - Storing (200) time-varying pressure fluctuation profiles for the stack receptacles (7) in the control unit (11), - Applying (210) water pressure fluctuations to the mixed water, which can be supplied via the stack inlets (16) to the anode chambers and/or the cathode chambers of the PEM stacks (S) to be conditioned, according to the stored pressure fluctuation profiles by means of pressure fluctuation devices.

Description

The present invention relates to a device for the mechanical conditioning of PEM stacks, each comprising an anode chamber and a cathode chamber, and to an associated conditioning method. PEM stacks (proton exchange membrane stacks) are central components of a PEM electrolyzer and are used for the electrochemical splitting of water into hydrogen and oxygen. A PEM stack typically consists of a large number of stacked individual cells made of plate-shaped components, arranged between two clamping plates (end plates) and pre-tensioned against each other fluidically by means of clamping devices – for example, screws or spring assemblies. As part of industrial production and quality assurance, fully assembled PEM stacks undergo a process called mechanical conditioning. Typically, the anode and cathode chambers of the PEM stack are exposed to temperature-controlled water (process water). The aim of this process is to deliberately induce settling within the PEM stack, allowing the clamping device to be readjusted so that the desired preload is achieved and the long-term operational reliability of the stack is ensured. Simultaneously, exposure to water enables a leak test of the stack under near-operational conditions. Mechanical conditioning typically takes place over several days and requires devices that ensure temperature control. Such devices for the mechanical conditioning of PEM stacks are already known in the prior art. DE 10 2024 125 854 A1 shows a corresponding device for conditioning an electrolysis device. Against this background, the invention aims to provide a device for the mechanical conditioning of PEM stacks that is characterized by improved practicality, particularly with regard to the possibility of conditioning several PEM stacks simultaneously and efficiently. This problem is solved by the device according to the invention for mechanically conditioning PEM stacks having one anode chamber and one cathode chamber according to claim 1, and by the method for mechanical conditioning according to claim 17. Advantageous embodiments are specified in the dependent claims. The device according to the invention for mechanically conditioning PEM stacks, each having an anode chamber and a cathode chamber, comprises - a hot water supply line providing hot water, - a cold water supply line providing cold water, - a mixed water return, - at least one or a plurality, preferably two or more, stack receptacles, each suitable for receiving a PEM stack to be conditioned, comprising a stack inlet through which mixed water can be supplied to the anode chamber and/or the cathode chamber, and a stack outlet through which the mixed water can be discharged from the anode chamber and/or the cathode chamber via the mixed water return, and - at least two adjustable mixing valves, each assigned to a stack receptacle, with a hot water inlet fluidically connected to the hot water supply, a cold water inlet fluidly connected to the cold water supply, and a mixed water outlet fluidically connected to the stack inlet of the associated stack receptacle, through which the mixed water of hot water and cold water, mixed according to the setting of the respective mixing valve, can be made available at the stack inlet of the associated stack receptacle. Through the synergistic interaction of the features according to the invention, the temperature of the mixed water flowing through the PEM stacks recorded in the stack images can be easily and precisely adjusted individually for each PEM stack. It has been shown that undesirable temperature shocks of the PEM stack can be avoided and thus the longevity of the PEM stack promoted if, at the beginning of the conditioning process, the stack is supplied with lukewarm mixed water of, for example, 20 to 40°C for a warm-up phase of (in particular) about 30 to 90 minutes, before the mixed water temperature is raised to about 60 to 80°C during the operating temperature phase of (in particular) about 2 to 3 days. The device according to the invention now makes it possible for each PEM stack to experience the appropriate temperature throughout the entire conditioning period, and also for PEM stacks This allows for the simultaneous conditioning of stacks that are in different conditioning phases and therefore require mixed water at different temperatures. This increases the utilization of the conditioning system, as it is now possible to begin conditioning another stack during the warm-up phase, even though the other stacks in the system are already being conditioned at operating temperature. Some features and aspects of the device according to the invention are explained and defined in more detail below: Mechanical conditioning of a PEM stack is understood here to mean the supply of tempered water to the anode chamber and/or the cathode chamber of the PEM stack, while the anodes and/or the cathodes of the PEM stack are (in particular) not subjected to electric current. In this context, hot water and