Device for the mechanical conditioning of PEM stacks and associated conditioning method

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 can be discharged from the anode chamber and / or the cathode chamber 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 determined by the setting of the respective mixing valve (6), can be supplied to the stack inlet (16) of the associated stack receptacle (7) via the mixed water outlets (6M) of the mixing valves.

Description

[0001] 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.

[0002] 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.

[0003] 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.

[0004] 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 art. DE 10 2024 125 854 A1 discloses a corresponding device for conditioning an electrolysis device.

[0005] 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.

[0006] 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.

[0007] 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.

[0008] 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.

[0009] 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.

[0010] The device according to the invention now makes it possible for each PEM stack to be kept at the appropriate temperature throughout the entire conditioning period, and also allows PEM stacks to be conditioned simultaneously even if they are in different conditioning phases and therefore require mixed water at different temperatures. This increases the utilization of the conditioning device, as it is now possible to begin conditioning another stack in the warm-up phase, even though the other stacks in the device are already being conditioned in the operating temperature phase.

[0011] 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 cold water are understood to mean water, in particular demineralized water (DI water), or a mixture of (demineralized) water and other liquids, such as antifreeze or alkali. Fluids include flowable media, especially gases and liquids.

[0012] Hot water with a temperature of, in particular, 60 to 70°C is supplied via the hot water supply line, and cold water with a temperature of, in particular, 5 to 20°C is supplied via the cold water supply line.

[0013] The formulation that two components, for example the hot water supply and the hot water inlet of a mixing valve, are fluidically connected expresses that, under suitable operating conditions and in particular with suitable switching of any valves, a fluid can flow from one of the two components to the other component.

[0014] Each mixing valve can be supplied with hot water and cold water and provides mixed water, i.e. a mixture of hot water and cold water, at its mixed water outlet, whereby the proportion of hot water and cold water in the mixed water can be adjusted by setting the mixing valve.

[0015] According to a first preferred embodiment of the invention, the device comprises - at least two inlet temperature sensors, each assigned to a stack inlet and arranged in the respective stack inlet, and suitable for recording the actual inlet temperature of the flowing (mixed) water, and - a control unit operatively connected to the inlet temperature sensors and the mixing valves, wherein - the control unit allows for the storage of a corresponding target inlet temperature of the mixed water for each stack recording, and - the control unit is configured to control the mixing valves based on the actual inlet temperatures detected by the inlet temperature sensors in such a way that the actual inlet temperature of the mixed water flowing through the respective stack inlet approaches the corresponding stored target inlet temperature.

[0016] In this way, each PEM stack to be conditioned can be easily and reliably supplied with individually temperature-controlled mixed water to enable precise conditioning. A particularly advantageous feature is that a time-dependent target inlet temperature profile can be stored in the control unit for each stack inlet. The control unit can then be configured so that, based on the actual inlet temperatures detected by the inlet temperature sensors, the mixing valves are controlled in such a way that the actual inlet temperature of the mixed water flowing through the respective stack inlet approaches the corresponding stored target inlet temperature according to the time-dependent target inlet temperature profile.

[0017] The target inlet temperature profile can be set up in such a way that at the beginning of the conditioning process, the stack has a target inlet temperature of 20 to 40°C during a warm-up phase (especially for a period of about 30 to 90 minutes), before the target inlet temperature is subsequently raised to 60 to 80°C during an operating temperature phase of about 2 to 3 days.

[0018] The process of bringing an actual temperature closer to a target temperature means that the difference between the actual and target temperatures is reduced until they only differ by a defined (relatively small) tolerance interval.

[0019] The unwanted spread of contaminants in the process water circuit of the device can be prevented by the device - at least two inlet conductance sensors, each arranged in one of the stack inlets and suitable for recording an actual inlet conductance and / or - at least two flow conductance sensors, each arranged in one of the stack flows and suitable for recording an actual flow conductance, and - comprises at least two controllable shut-off valves, each arranged in one of the stack inlets and / or one of the stack outlets and suitable for shutting off the mixed water flow through the associated stack inlet and / or stack outlet, wherein - the conductance sensors and the shut-off valves are operatively connected to the control unit, - the control unit is suitable for receiving the actual inlet conductivity values ​​and / or the actual outlet conductivity values ​​and is configured to control the associated shut-off valve in such a way that the mixed water flow through the associated stack inlet and / or stack outlet is shut off if a (stored) maximum conductivity value is exceeded by one of the actual inlet conductivity values ​​and / or one of the actual outlet conductivity values.

[0020] The conductivity of water is a measure of its ability to conduct electricity. It is typically measured in microsiemens per centimeter (µS / cm) and indicates the number of dissolved ions present in the water. These ions can be either positively charged cations or negatively charged anions. A high conductivity in the process water of a PEM stack during mechanical conditioning indicates the presence of dissolved ionic impurities.

[0021] Since these contaminants can impair the efficiency and lifespan of a PEM stack, when conditioning multiple PEM stacks together, the spread of these contaminants from a contaminated PEM stack to the neighboring non-contaminated PEM stacks should be prevented by closing the "associated shut-off valve", i.e., the shut-off valve assigned to the stack in which the maximum conductivity was exceeded, thus preventing the circulation of (process) water through the contaminated PEM stack.

[0022] It is particularly advantageous that the device according to the invention - a hot water tank fluidically connected to the hot water supply for the provision of hot water, and - comprising a cold water tank fluidically connected to the cold water supply for the provision of cold water, wherein - the mixed water return line is fluidically connected to the hot water tank and / or the cold water tank and is optional - the hot water tank and / or the cold water tank must have a vent valve.

[0023] Alternatively, the device may be provided with a stratified water storage tank fluidically connected to the hot water supply, the cold water supply and the mixed water return.

[0024] A stratified storage tank (also called a layered storage tank) is a water storage tank designed to store the water contained within it in temperature layers, i.e., to thermally "stratify" it. Differently tempered layers of water within the storage volume are kept as stable as possible in order to efficiently utilize the heat content and minimize temperature losses.

[0025] Furthermore, it may be provided that the device - at least one pump located in the hot water supply line and / or in the cold water supply line, and / or - a flow heater device arranged in the hot water supply line, and / or - has a heating device located in the hot water tank.

[0026] In particular, the hot water tank and the cold water tank or the layered water storage tank are arranged geodetically below the stack outlets and / or below the stack inlets of the stack receptacles.

[0027] In this way, the mixed water can flow back via the stack outlets along a gradient through the mixed water return line and / or via the stack inlets along a gradient through the hot water supply or hot water return or the cold water supply or cold water return.

[0028] A particularly efficient conditioning device can be implemented if - the hot water supply and a hot water return form a hot water circuit, and - the cold water supply and a cold water return form a cold water circuit, and in particular - the device has a heat exchanger between the hot water return and the cold water supply.

[0029] The mixed water volume flows through the stack inlets can be individually adjusted and regulated if the device has at least two throttling devices, each located in one of the stack inlets.

[0030] In this way, identical mixed water flow rates can be achieved across all stack inlets – despite differing pressure losses and pipe lengths to the individual stack inlets. The mixing devices can be designed to also perform the function of the throttling devices – for example, by having a proportional valve in both the hot and cold water inlets, allowing stepless adjustment between fully open and fully closed.

[0031] The unwanted spread of contaminants in the process water circuit of the device can be prevented particularly reliably if the device - a hot water bypass fluidically connecting the hot water supply to the mixed water return with a hot water bypass valve, and - a cold water bypass connecting the cold water supply and the mixed water return fluidically, using a cold water bypass valve, exhibits, whereby - the bypass valves are operatively connected to the control unit, and - the control unit is configured to control the bypass valves in such a way that hot water from the hot water supply can be pumped through the hot water bypass into the mixed water return and cold water from the cold water supply can be pumped through the cold water bypass into the mixed water return.

[0032] The PEM stacks to be conditioned can be mounted and dismounted in the device particularly easily and reliably by - the stack inlets and the stack outlets each include a coupling plate, and - the stack receptacles have actuators, each assigned to one of the coupling plates and configured to move the coupling plates into a pressed-on position and a lifted-off position, whereby in the pressed-on position a fluidically tight connection is established between the respective PEM stack and the stack inlet and the stack outlet of the associated stack receptacle.

[0033] In order to further provoke settling of the PEM stacks to be conditioned during the conditioning phase, it can be provided that the coupling plates and the at least one actuator of a stack holder each form a clamping device by means of which a (time-varying) clamping force can be applied to the PEM stack held.

[0034] The maximum clamping force is advantageously between 10 and 30 t-force equivalent, in particular between 15 and 25 t-force equivalent, where one t-force equivalent corresponds to the weight force of one metric ton of mass (1000 kg) under the standard acceleration due to gravity.

[0035] Provoking settling movements within the PEM stack to be conditioned is further aided if - each stack inlet has a pressure fluctuation device designed 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 via the respective stack inlet, and - the pressure fluctuation devices in particular each have a compression piston and a compression volume fluidically connected to the mixed water outlet of the associated mixing valve and the size of the compression volume can be varied by means of the compression piston.

[0036] The water pressure fluctuation is at least 1 bar, preferably at least 5 bar.

[0037] It has been found that it can be particularly advantageous if only the cathode chamber, but not the anode chamber, is exposed to pressure fluctuations, especially when the PEM stacks are designed for pressurized electrolysis systems. In pressurized electrolysis systems, the cathode side is under a pressure of 20 bar or more relative to the anode side during operation. To enable this, the stack inlets can each be provided with an anode shut-off valve located downstream of the respective pressure fluctuation device. When closed, this valve prevents the supply (flow) of mixed water through the stack inlet into the anode chamber of the associated PEM stack.

[0038] In this way, the water pressure fluctuation can be specifically applied only to the cathode chamber, in order to further accelerate the setting process.

[0039] The spread of contaminants in the process water of the device during conditioning can be prevented if the device - a water treatment device, particularly located in the mixed water return line, for filtering impurities from the mixed water, and - optionally features a water treatment bypass.

[0040] The water treatment device can be designed, in particular, as a mixed-bed filter. The water treatment bypass allows the process water to be routed around the water treatment device.

[0041] Particularly simple and thorough venting of the PEM stacks to be conditioned at the beginning of the conditioning process can be achieved by arranging the stack inlets geodetically below the stack outlets.

[0042] The mixed water is thus conveyed "from bottom to top" through the PEM stacks. In this way, the air present in the PEM stacks at the beginning of the conditioning process can be easily and thoroughly removed / driven out.

[0043] The present invention is also manifested in the method for mechanically conditioning PEM stacks, each having an anode chamber and a cathode chamber, by means of a mechanical conditioning device according to the invention, comprising the following steps: - Providing the PEM stacks to be conditioned in the device for mechanical conditioning, wherein the PEM stacks are each held in a stack holder and a mixed water can be supplied to the anode chamber and / or the cathode chamber via a stack inlet and the mixed water can be discharged from the anode chamber and / or the cathode chamber via a stack outlet, - Storing target inlet temperatures of the mixed water for the stack recordings in the control unit, - Recording the actual inlet temperatures of the mixed water flowing through the stack inlets using the inlet temperature sensors and transmitting the actual inlet temperatures to the control unit, and - The control unit controls the mixing valves in such a way that the actual inlet temperature of the mixed water flowing through the respective stack inlet approaches the corresponding stored target inlet temperature.

[0044] It should be expressly mentioned at this point that the advantageous embodiments of the conditioning device described above can be used in the method according to the invention.

[0045] Preferably, the procedure further comprises the following steps: - Storing time-dependent target inlet temperature profiles for stack recordings in the control unit, and - The control unit controls the mixing valves in such a way that the actual inlet temperature of the mixed water flowing through the respective stack inlet approaches the corresponding stored target inlet temperature according to the corresponding time-dependent target inlet temperature profile.

[0046] Furthermore, the procedure may include the following steps: - Storing a maximum conductance value in the control unit, - Recording the actual inlet conductivity values ​​and / or actual outlet conductivity values ​​of the mixed water flowing through the stack inlets using inlet conductivity sensors and / or outlet conductivity sensors and transmitting the actual conductivity values ​​to the control unit, and - when the control unit detects that the maximum conductivity value has been exceeded by one of the actual conductivity values, the control unit activates a shut-off valve in such a way that the mixed water flow through the associated stack inlet and / or stack outlet is shut off.

[0047] Furthermore, the method according to the invention may preferably comprise the following steps: - Storing time-varying clamping force profiles for the stack mounts in the control unit, and - Applying clamping forces, particularly time-varying ones, to the PEM stacks according to the stored clamping force profiles using clamping devices, and / or - Storing time-varying pressure fluctuation profiles for stack recordings in the control unit, - Applying water pressure fluctuations to the mixed water, which can be supplied to the anode chambers and / or the cathode chambers of the PEM stacks to be conditioned via the stack inlets, according to the stored pressure fluctuation profiles by means of pressure fluctuation devices.

[0048] Two exemplary embodiments of the device according to the invention are explained in more detail below with reference to the drawings. The drawings show Fig. 1 a schematic circuit diagram of a first embodiment of the device according to the invention, Fig. 2 a schematic circuit diagram of a second embodiment of the device according to the invention, and Fig. 3 a flowchart to illustrate a method according to the invention.

[0049] The in Fig. The first embodiment of a device 1 according to the invention for mechanical conditioning (conditioning device) shown in Figure 1 is suitable for accommodating three PEM stacks S, each with an anode chamber and a cathode chamber. However, a conditioning device according to the invention is also conceivable that can accommodate significantly more PEM stacks, for example 10 to 20.

[0050] The conditioning device 1 comprises a hot water circuit 2 with a hot water tank 3, a cold water circuit 4 with a cold water tank 5, three mixing valves 6, three stack receptacles 7, a mixed water return 8 with a water treatment device 9 including a water treatment bypass 10 and a control unit 11.

[0051] The hot water circuit 2 has a hot water supply 2V and a hot water return 2R, both of which lead into the hot water tank 3. A hot water pump 12, located in the hot water supply 2V, circulates hot water within the hot water circuit 2 and supplies it to the hot water supply 2V. A flow heater 13 is located in the hot water supply 2V to further heat the hot water flowing through it, and a heating device 14 is located in the hot water tank 3. Temperature sensors 13S are located upstream and downstream of the flow heater 13 to detect the temperature of the flowing water and transmit it to the control unit 11.

[0052] The cold water circuit 4 is largely analogous to the hot water circuit 3 and has a cold water supply 4V, a cold water return 4R and a cold water pump 15 arranged in the cold water supply 4V.

[0053] The three stack receptacles 7 are each suitable for receiving a PEM stack S to be conditioned and comprise a stack inlet 16, through which mixed water can be supplied to the anode chamber and the cathode chamber, and a stack outlet 17, through which the mixed water can be discharged from the anode chamber and the cathode chamber.

[0054] The adjustable mixing valves 6 each have 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, through which the mixed water from hot water and cold water, mixed according to the setting of the respective mixing valve 6, can be supplied to the stack inlet 16 of the associated stack receptacle 7.

[0055] Between the mixing valves 6 and the associated stack inlets 16, an inlet temperature sensor 18 and a throttling device 19 are arranged.

[0056] The stack inlets 16 and the stack outlets 17 each have a coupling plate 20 by means of which a fluidically tight connection with the PEM stacks S can be established. The stack receptacles 7 each have an actuator 21 which is assigned to the coupling plate 20 of the associated stack inlet 16 and is configured to move the associated coupling plate 20 into a pressed-in position and a lifted-off position, whereby in the pressed-in position a fluidically tight connection is established between the respective PEM stack S and the associated stack inlet 16 and the associated stack outlet 17, and in the lifted-off position the associated PEM stack S can be removed from the stack receptacle 7.

[0057] The stack feed 16, the stack discharge 17 and the actuator 21 of a stack holder 7 form a clamping device by means of which a clamping force that can be varied over time can be applied to the PEM stack S that has been received.

[0058] Actuator 21 can be a pneumatic or a hydraulic actuator. Other actuator types, e.g., electromechanical ones, are possible.

[0059] The inlet temperature sensors 18 are each suitable for recording the actual inlet temperature of the flowing mixed water and transmitting it to the control unit 11.

[0060] The stack drains 17 are each fluidically connected to the mixed water return 8, wherein a drain conductivity sensor 22, a drain temperature sensor 23 and a shut-off valve 24 are arranged between the stack drains 17 and the mixed water return 8.

[0061] In the hot water supply line 2V and the cold water supply line 4V, a supply conductance sensor 25 is arranged upstream of the respective pump 12, 15.

[0062] The conductivity sensors 22 and 25 are each suitable for detecting the actual conductivity of the flowing water and transmitting it to the control unit 11. The shut-off valves 24 are suitable for shutting off and thus preventing the flow of the mixed water (mixed water flow) through the associated stack drain 17.

[0063] The mixed water return 8 is fluidically connected to the hot water tank 3 and the cold water tank 5.

[0064] The conditioning device 1 further comprises a hot water bypass 26 fluidically connecting the hot water supply 2V with 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 with the mixed water return 8, with a cold water bypass valve 29.

[0065] The mixing valves 6, the sensors 18, 22, 23, 25, the throttling devices 19, the shut-off valves 24, the bypass valves 27, 29 and the pumps 12, 15 are operatively connected to the control unit 11.

[0066] The control unit 11 contains a maximum conductivity value and time-dependent target inlet temperature profiles for the individual stack recordings 7.

[0067] The control unit 11 is configured to control the mixing valves 6 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.

[0068] The control unit 11 is further configured to receive the actual conductivity values ​​and, if the maximum conductivity value is exceeded by one of the actual discharge conductivity values, to actuate the associated shut-off valve 24 such that the mixed water flow through the associated stack discharge 17 is shut off. If the maximum conductivity value is exceeded by one of the actual supply conductivity values, the control unit 11 is configured to actuate the bypass valves 27, 29 such that hot water from the hot water supply 2V is pumped through the hot water bypass 27 into the mixed water return 8 and cold water from the cold water supply 4V is pumped through the cold water bypass 28 into the mixed water return 8, in order to keep the contaminated water (process water) away from the PEM stacks S in this way.

[0069] The second embodiment according to Fig. 2 differs from the first embodiment according to Fig. 1 essentially in that the device 1 has a stratified water storage tank 30 instead of a hot water tank 3 and a cold water tank 5. To avoid repetition, only the essential differences between the two embodiments will be discussed below. Similar or identical components are designated with identical reference numerals in both embodiments.

[0070] The stratified water storage tank 30 is fluidically connected to the hot water supply 2V, the hot water return 2R, the cold water supply 4V, the cold water return 4R, and the mixed water return 8. A heating device 14 is arranged in the upper area of ​​the stratified water storage tank 30. Fig. Figure 2 shows a series of optional heat exchangers 31, with the help of which heat energy can be shifted between the hot water circuit and the cold water circuit, or coupled out of or into the hot water circuit, the cold water circuit or the mixed water return, in order to increase the energy efficiency of the conditioning device 1.

[0071] Based on the flowchart according to Fig. 3 A method 100 according to the invention for mechanically conditioning PEM stacks S having an anode chamber and a cathode chamber respectively by means of a device 1 according to the invention for mechanical conditioning is described in more detail: In step 110, the PEM stacks S to be conditioned are first provided in the device 1 for mechanical conditioning, wherein the PEM stacks S are each held in a stack holder 7 and a mixture of water from the anode chamber and the cathode chamber can be supplied via a stack inlet 16 and a mixture of water from the anode chamber and the cathode chamber can be discharged via a stack outlet 17.

[0072] According to step 120, target inlet temperatures of the mixed water for the stack recordings 7 are stored in the control unit by storing time-dependent target inlet temperature profiles for the stack recordings 7 (step 125).

[0073] The conditioning of the PEM stacks S then starts by starting pumps 12 and 15 and providing hot and cold water in the respective supply lines 2V and 4V.

[0074] According to step 130, the actual inlet temperatures of the mixed water flowing through the stack inlets 7 are recorded by the inlet temperature sensors 18 and transmitted to the control unit 11.

[0075] Based on this, in steps 140 and 145, the mixing valves 6 are controlled in parallel 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.

[0076] According to step 150, a maximum conductance value that must not be exceeded is stored in control unit 11.

[0077] During the conditioning process, according to step 160, actual effluent conductivity values ​​of the mixed water flowing through the stack inlets 7 are recorded by effluent conductivity sensors 22 and transmitted to the control unit 11.

[0078] If, according to step 170, the control unit 11 detects that the maximum conductivity is exceeded by one of the actual conductivity values, the control unit 11 activates a shut-off valve 24 in such a way that the mixed water flow through the associated stack drain 17 is shut off.

[0079] According to step 180, time-varying clamping force profiles for the stack mounts 7 are stored in the control unit 11 and according to step 190, time-varying clamping forces are applied to the PEM stacks according to the stored clamping force profiles by means of clamping devices.

[0080] In addition, according to step 200, time-varying pressure fluctuation profiles for the stack inlets 7 are stored in the control unit 11, and according to step 210, water pressure fluctuations are applied to the mixed water, which can be supplied to the anode chambers and the cathode chambers of the PEM stacks to be conditioned via the stack inlets 16, according to the stored pressure fluctuation profiles by means of pressure fluctuation devices. Reference symbol list 1 Device 2 Hot water circuit 2V hot water supply 2R Hot water return 3 hot water containers 4 Cold water circuit 4R Cold water return 4V cold water supply 5 cold water tanks 6 Mixing valve 6H Hot water inlet 6K Cold water inlet 6M mixed water drain 7 Stack recording 8 Mixed water return 9 Water treatment device 10 Water treatment bypass 11 Control unit 12 Hot water pump 13 Flow heater device 13S temperature sensor 14 Heating device 15 Cold water pump 16 Stack feed 17 Stack Flow 18 Inlet temperature sensor 19 Throttle device 20 coupling plate 21 Actuator 22 Flow conductance sensor 23 Drain temperature sensor 24 shut-off valve 25 Flow conductance sensor 26 Hot water bypass 27 Hot water bypass valve 28 Cold water bypass 29 Cold water bypass valve 30 layered water storage tanks 31 heat exchangers S PEM stack

Claims

Device (1) for mechanically conditioning 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).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), via which the mixed water of hot water and cold water, mixed according to the setting of the respective mixing valve (6), can be supplied to the stack inlet (16) of the associated stack receptacle (7). Device (1) according to claim 1, comprising: - at least two inlet temperature sensors (18), each assigned to a stack receptacle (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 receptacle (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 stored target inlet temperature. Target inlet temperature approached. 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 controlling the To receive and be set up to receive actual inflow conductivity values ​​and / or actual outflow conductivity values,If a maximum conductivity value is exceeded by one of the actual inlet conductivity values ​​and / or one of the actual outlet conductivity values, the associated shut-off valve (24) is controlled in such a way that the mixed water flow through the associated stack inlet (16) and / or stack outlet (17) is shut off. 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. 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). Device (1) according to one of the preceding claims, comprising at least one pump (12, 15) arranged in the hot water supply (2V) and / or in the cold water supply (4V), 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). Device (1) according to one of claims 4 to 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 receptacles (7). 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). 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). Device (1) according to one of the preceding claims, comprising: - a hot water bypass (26) fluidically connecting the hot water supply (2V) with the mixed water return (8) and a hot water bypass valve (27); and - a cold water bypass (28) fluidically connecting the cold water supply (4V) with the mixed water return (8) and 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) in such a way that 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) flows through the cold water bypass (28) and a cold water bypass valve (29). the cold water bypass (28) can be pumped into the mixed water return (8). 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-on position and a lifted-off position, wherein in the pressed-on 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. Device (1) according to 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, in particular variable over time, can be applied to the received PEM stack (S). 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 which 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 can be varied by means of the compression piston. Device (1) according to 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. 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). Device (1) according to one of the preceding claims, wherein the stack inlets (16) are arranged geodetically below the stack outlets (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 any one of claims 2 to 15 comprising 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 received in a stack receptacle (7) and a mixture of water from the anode chamber and / or the cathode chamber can be supplied via a stack inlet (16) and the mixture can be discharged from the anode chamber and / or the cathode chamber via a stack outlet (17), - Storing (120) target inlet temperatures of the mixture for the stack receptacles (7) in the control unit (11), - Detecting (130) actual inlet temperatures of the mixture supplied by the Stack recordings (7) of flowing mixed water through the inlet temperature sensors (18) and transmit the actual inlet temperatures to the control unit (11),and- Controlling (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. Method (100) according to claim 17 comprising 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 associated stored target inlet temperature according to the associated time-dependent target inlet temperature profile. Method (100) according to claim 17 or 18 comprising 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 - upon detection of an exceedance of the maximum conductivity value by one of the actual conductivity values ​​by the control unit (11), 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. Method (100) according to any one of claims 17 to 19 comprising the following steps: - Storing (180) time-varying clamping force profiles for the stack receptacles (7) in the control unit (11), and - Applying (190) in particular time-varying clamping 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 to the anode chambers and / or the cathode chambers of the PEM stacks (S) to be conditioned via the stack inlets (16), according to the stored pressure fluctuation profiles by means of pressure fluctuation devices.

Images