Electrochemical cell system

Abstract

Electrochemical cell system (11) comprising an electrochemical cell unit (25) for converting electrochemical energy into electrical energy as a fuel cell unit (1) and / or for converting electrical energy into electrochemical energy as an electrolysis cell unit (6), comprising stacked electrochemical cells (24) as a cell stack (10), a housing (13) for the cell stack (24) and the cell stack (24) being arranged within the housing (13), a subsystem (40) for the cell stack (24), a fastening device (46) for fastening the subsystem (40) to the housing (13) of the cell stack (24) and the subsystem (40) being attached to the housing (13) by the fastening device (46), wherein the electrochemical cell unit (24) comprises a centering device (47) with a contact geometry (50) and a counter-contact geometry (51) for positioning the subsystem (40) relative to the housing (13) for the cell stack (10).

Description

The present invention relates to an electrochemical cell system according to the preamble of claim 1.Prior ArtFuel cell units as galvanic cells convert continuously supplied fuel and oxidizing agent into electrical energy and water by means of redox reactions at an anode and cathode. Fuel cells are used in a wide variety of stationary and mobile applications, for example in houses without connection to an electrical grid or in motor vehicles, in rail traffic, in aircraft, in space and in ship travel. In fuel cell units, a plurality of fuel cells are arranged in a stack.In fuel cell units, a large number of fuel cells are arranged in a fuel cell stack. Within the fuel cells, a gas space for oxidizing agent is present in each case, that is to say a flow space for the passage of oxidizing agent, such as air from the environment, with oxygen. The gas space for oxidizing agent is formed by channels on the bipolar plate and by a gas diffusion layer for a cathode. The channels are thus formed by a corresponding channel structure of a bipolar plate and the oxidizing agent, namely oxygen, reaches the cathode of the fuel cells through the gas diffusion layer. Analogously, a gas space for fuel is formed at an anode. Electrolysis cell units comprising electrolysis cells arranged in a stacked manner, analogously to fuel cell units, serve, for example, for the electrolytic recovery of hydrogen and oxygen from water. Furthermore, fuel cell units are known which can be operated as reversible fuel cell units and thus as electrolysis cell units.A fuel cell system including a fuel cell unit includes an oxidant supply system, a fuel supply system, and a coolant supply system. An electrolytic cell system includes an electrolyte supply system. Fuel cell systems and electrolysis cell systems form electrochemical cell systems. The oxidant supply system, the fuel supply system, the coolant supply system and the electrolyte supply system each form a subsystem for an electrochemical cell system. The subsystem includes a subsystem housing having a subsystem interface board. The subsystem terminal plate faces the electrochemical cell unit. The subsystem port plate has an opening. The opening of the subsystem terminal plate is sealed with a seal between the electrochemical cell unit and the subsystem. The subsystem is fastened to the electrochemical cell unit, in particular the housing of the electrochemical cell unit, by a fastening device. For the alignment and positioning of the subsystem relative to the electrochemical cell unit, local pins having a substantially pin shape in section are formed on the subsystem and / or on the electrochemical cell unit. The pins and a bore in which the pins are arranged have no function for the seal. Due to the structural properties, the pins and the bore cannot be produced jointly by machining with a bearing surface for the seal. The pins and the bore on the one hand and the bearing surface for the seal on the other hand are thus to be produced in separate working steps, in particular by machining. This disadvantageously results in high costs.EP 1 255 660 81 discloses a device with a fuel cell for generating electrical energy and distributing the electrical energy to electrical consumers which are arranged in a high-voltage line network connected to the fuel cell, and to further electrical consumers which are arranged in a low-voltage line network which is connected to the high-voltage line network via a DC-DC converter, characterized in that a central monitoring and switching unit has a housing which can be fastened detachably to the fuel cell housing and in which are arranged electrical conductors which are connected via feedthroughs in a housing wall and contact means in each case to an electrical output of the fuel cell, and of which at least one has a contact of a fuel cell circuit breaker, and in that the conductors have fuses via branches which are provided at least with single poles, and feedthroughs in a housing wall and contact means are connected to consumers, and the low-voltage line network is connected via a feedthrough to a control and evaluation unit belonging to the central monitoring and switching unit, the control and evaluation unit is connected via feedthroughs in a housing wall and contact means to sensors for detecting operating states of the device, and the feedthroughs in the housing walls are dust-proof and watertight and the contact means are detachable.EP 2 497 142 B1 shows a fuel cell arrangement comprising a main housing with a main housing interior which is gas-tight with respect to the environment and in which at least one reformer, a reformer burner supplying the reformer with thermal energy and a fuel cell stack are located, wherein the main housing has at least one air connection, and wherein at least one blower is provided which, during operation, draws air through the air connection into the main housing interior, wherein the fuel cell stack is arranged in a fuel cell housing which is arranged within the main housing interior and is adapted to the shape of the fuel cell stack so that it encloses the fuel cell stack at a small distance, wherein the fuel cell housing has at least one suction opening connected to the main housing interior and at least one connection to a suction line connected to the suction side of the blower, and wherein a burner line connected to an inlet opening of the reformer burner is connected to the pressure side of the blower.Disclosure of the InventionAdvantages of the InventionElectrochemical cell system according to the invention having an electrochemical cell unit for converting electrochemical energy into electrical energy as a fuel cell unit and / or for converting electrical energy into electrochemical energy as an electrolysis cell unit, comprising electrochemical cells arranged in a stacked manner as a cell stack, a housing for the cell stack and the cell stack being arranged within the housing, a subsystem for the cell stack, a fastening device for fastening the subsystem to the housing of the cell stack and the subsystem having the fastening device being fastened to the housing, wherein the electrochemical cell unit comprises a centring device having a contact geometry and a countercontact geometry for positioning the subsystem relative to the housing for the cell stack. An electrochemical cell system includes an electrochemical cell unit and at least one subsystem.In a further embodiment, the contact geometry is formed on a recess of the contact component and / or the counter-contact geometry is formed on a projection of the counter-contact component.In an additional embodiment, the contact geometry is formed on a projection of the contact component and / or the counter-contact geometry is formed on a recess of the counter-contact component.In a further embodiment, the recess is formed completely circumferentially, in particular annularly, on the contact component.In an additional embodiment, the projection is formed completely circumferentially, in particular annularly, on the mating contact component.The contact component is preferably formed at least partially, in particular completely, integrally with the housing for the cell stack and / or the mating contact component is formed at least partially, in particular completely, integrally with a subsystem housing.Expediently, the contact component is formed at least partially, in particular completely, integrally with the subsystem housing and / or the mating contact component is formed at least partially, in particular completely, integrally with the housing for the cell stack.In a further embodiment, the contact component on the contact geometry and the counter-contact component on the counter-contact geometry lie on top of one another.In an additional embodiment, the contact geometry and the counter-contact geometry are aligned substantially, in particular with a deviation of less than 30°, 20° or 10°, parallel to a direction of movement of the subsystem during the mounting and fastening of the subsystem to the housing as an axial direction.In a further variant, the contact geometry and the counter-contact geometry are oriented as an axial direction at an acute angle to a direction of movement of the subsystem during the assembly and fastening of the subsystem to the housing, such that the contact geometry and the counter-contact geometry are designed conically.In a supplementary embodiment, the contact geometry and the counter-contact geometry are formed to be complementary to one another, in particular planar.Expediently, a seal is formed between the contact component and the mating contact component, in particular between the contact geometry and the mating contact geometry, wherein the seal is formed in particular in a direction perpendicular to a circumferential direction between the contact geometry and the mating contact geometry.In a further variant, the seal is formed completely circumferentially, in particular annularly.In an additional embodiment, the contact geometry and the counter-contact geometry are formed in the circumferential direction with a circumferential angle α of at least 30° or 90°, in particular completely circumferentially with a circumferential angle of 360°.In a supplementary embodiment, the subsystem comprises a subsystem housing and the subsystem for the electrochemical cell stack is arranged within the subsystem housing.In an additional embodiment, the contact component and the mating contact component are formed in the circumferential direction with a circumferential angle α of at least 30° or 90°, in particular completely circumferentially with a circumferential angle of 360°.In a further embodiment, the projection is arranged in the recess, in particular completely circumferentially in the circumferential direction.In an additional embodiment, the seal rests, in particular directly, on the contact geometry and / or the counter-contact geometry. No additional machining is therefore necessary for supporting the seal, because the machined contact geometry and / or counter-contact geometry is used for supporting the seal.Preferably, the contact component is formed at least partially, in particular completely, by the housing for the cell stack and the mating contact component is formed at least partially, in particular completely, by a subsystem housing.Expediently, the contact component is formed at least partially, in particular completely, by a subsystem housing and the mating contact component is formed at least partially, in particular completely, by the housing for the cell stack.In a further variant, the contact component is designed as a separate contact component, in particular in addition to the housing and / or the subsystem housing.In a further variant, the mating contact component is designed as a separate mating contact component, in particular in addition to the housing and / or the subsystem housing.In an additional embodiment, the seal and / or the contact component and / or the mating contact component and / or the contact geometry and / or the mating contact geometry and / or the projection and / or the recess are formed in the circumferential direction with a circumferential angle α of at least 30° or 90°, in particular completely circumferentially with a circumferential angle α of 360°, and / or are formed in the region of the opening of the subsystem housing, in particular with a distance of less than 20 cm, 10 cm, 5 cm or 3 cm from the opening of the subsystem housing.In a supplementary variant, at least two seals and / or at least two contact components and / or at least two mating contact components and / or at least two contact geometries and / or at least two mating contact geometries and / or at least two mating contact geometries and / or at least two projections and / or at least two recesses are formed for one subsystem in each case.In an additional embodiment, only one seal and / or only one contact component and / or only one counter-contact component and / or only one contact geometry and / or only one counter-contact geometry and / or only one projection and / or only one recess are formed for each subsystem.In an additional embodiment, the distance of the seal and / or contact component and / or counter-contact component and / or contact geometry and / or counter-contact geometry to the boundary of the opening of the subsystem housing is less than 10 cm or 5 cm.In a further variant, the contact component and the mating contact component are formed by the seal.Preferably, the opening of the subsystem housing is bounded by the subsystem housing, in particular the subsystem connection plate.In a supplementary variant, the seal is formed at least partially, in particular completely, from an elastic material and / or from an elastomer and / or from plastic, preferably HPU and / or PU and / or NBR and / or FPM and / or FKM and / or EPDM and / or silicone and / or PTFE and / or POM and / or PA and / or PA 6 G and / or rubber.Preferably, the diameter of the seal is greater than 1 mm, 3 mm or 5 mm.In a supplementary variant, the seal and / or the contact component and / or the mating contact component are formed completely continuous in the circumferential direction, in particular in a section perpendicular to the axial direction.In a supplementary variant, the seal and / or the contact component and / or the mating contact component are designed, in particular in a section perpendicular to the axial direction, to be ellipsoidal, in particular circular, or rectangular, in particular square.In an additional variant, the length of the boundary of the opening on the subsystem housing in the circumferential direction corresponds substantially, in particular with a deviation of less than 30%, 20% or 10%, to the length of the seal and / or contact component and / or counter-contact component and / or contact geometry and / or counter-contact geometry in the circumferential direction.In a further variant, the length of the seal and / or contact component and / or counter-contact component and / or contact geometry and / or counter-contact geometry in the circumferential direction corresponds to at least 10%, 30%, 50% or 70% of the diameter, in particular of the maximum diameter, of the subsystem.In a further variant, the length of the seal substantially corresponds, in particular with a deviation of less than 30%, 20% or 10%, to the length of the contact component and / or mating contact component and / or contact geometry and / or mating contact geometry, in particular in the circumferential direction.In a further embodiment, the seal is arranged, in particular exclusively, between the contact component and the mating contact component.In an additional embodiment, the seal is formed in one piece.In a further embodiment, the electrochemical cell system comprises a seal, in particular only a seal, for sealing between a subsystem housing of a subsystem in each case and the housing of the electrochemical cell unit in each case.The subsystem is preferably designed as an oxidant supply system and / or a fuel supply system and / or a coolant supply system and / or an electrolyte supply system and / or an electrical system. The electrical system preferably serves for conducting electrical energy from and / or to the electrochemical cell unit.Preferably, the electrical system comprises a battery and / or a transformer and / or an inverter and / or an AC / DC converter.In a further embodiment, the direction of movement and / or axial direction for each subsystem is substantially, in particular with a deviation of less than 30°, 20° or 0°, perpendicular to a wall, in particular connection plate, of the housing of the electrochemical cell unit facing the respective one subsystem and preferably the respective one subsystem is fastened to this wall of the housing with the fastening device and / or the contact component and / or counter-contact component is formed on this wall facing the respective one subsystem.In a further embodiment, the seal is arranged in a groove.Preferably, the groove for the seal is formed on the contact component and / or on the mating contact component.In an additional variant, the contact geometry and the countercontact geometry are configured exclusively planar, in particular at the region of contact between the contact geometry and the countercontact geometry.In a further embodiment, the fuel cell system comprises a fuel supply system with a pressure vessel for fuel as hydrogen as a process fluid and an oxidant supply system with a gas delivery device for oxidant as a process fluid.In a supplementary variant, the fuel cell system comprises a fuel cell unit, a cooling system, an oxidizing agent supply system and a fuel supply system.In a further embodiment, the electrolysis cell system comprises an electrolysis cell unit and an electrolyte supply system.Preferably, the fuel is hydrogen, hydrogen-rich gas, reformate gas or natural gas.Expediently, the electrochemical cells and / or components of the electrochemical cells are substantially planar and / or disk-shaped.In a further variant, the electrochemical cell unit comprises a housing and / or a connection plate. The stack is enclosed by the housing and / or the connection plate.Conveniently, the subsystem comprises a subsystem housing and a subsystem interface board. The subsystem connection plate as a wall of the subsystem housing preferably faces the electrochemical cell unit.In a supplementary variant, the oxidizing agent is air with oxygen or pure oxygen.In a further embodiment, the at least one electrolysis cell unit is a PEM electrolysis cell unit and / or a SOFE high-temperature electrolyser.Preferably, the fuel cell unit is a PEM fuel cell unit including PEM fuel cells, or an SOFC fuel cell unit including SOFC fuel cells, or an alkaline fuel cell (AFC).Brief Description of the DrawingsExemplary embodiments of the invention are described in more detail below with reference to the attached drawings. It shows: FIG. 1 shows a greatly simplified illustration of a fuel cell system, FIG. 2 shows a greatly simplified illustration of an electrolysis cell system, FIG. 3 shows a section through a centering device for a subsystem of an electrochemical cell unit in a first exemplary embodiment, FIG. 4 shows a section through the centering device for the subsystem of the electrochemical cell unit in a second exemplary embodiment, FIG. 5 shows a section through the centering device for the subsystem of the electrochemical cell unit in a third exemplary embodiment, FIG. 6 shows a section perpendicular to the plane of the drawing of FIG. 3, 4 or 5 and parallel to the circumferential direction only through the seal in a first exemplary embodiment, FIG. 7 shows a section perpendicular to the plane of the drawing of FIG. 3, 4 or 5 and parallel to the circumferential direction only through the seal in a second exemplary embodiment, FIG. 8 shows a section parallel to the circumferential direction only through the seal in a third exemplary embodiment, and FIG. 9 shows a side view of a fuel cell unit with subsystem.FIG. 1 shows a fuel cell unit 1 as a fuel cell stack 3, i.e. as a fuel cell stack 3. The fuel cell unit 1 comprises the fuel cell stack 3 as an electrochemical cell stack 10, a housing 13 and a connection plate 15. The housing 13 delimits an interior space 14. The connection plate 15 also functions as a housing 13 and is fixed to the remaining housing 13 by means of fixing elements 16, in particular screws 17. In the fuel cell stack 2, fuel cells 4 as PEM fuel cells 5 are stacked and aligned. Due to the large number of stacked fuel cells 4 of approximately 300 to 400 fuel cells 4, these are not all shown in FIG. 1 for reasons of simplification. The principle of fuel cells 4 is that electrical energy or electrical current is generated by means of an electrochemical reaction. Hydrogen H 2 is supplied as a gaseous fuel as a recirculation fuel to an anode (not shown), and the anode forms the negative pole. A gaseous oxidizing agent, namely air with oxygen, is conducted to a cathode (not shown), i.e. the oxygen in the air provides the necessary gaseous oxidizing agent. A reduction (electron uptake) takes place at the cathode. The oxidation as electron emission is carried out at the anode. The fuel cells 4 also include an ion exchange membrane as a proton exchange membrane (PEM) which is arranged between the anode and the cathode. On both sides of the PEM, facing gas spaces, respectively, the electrodes rest as the anode and cathode (not shown). A unit of the PEM and anode and cathode is referred to as a membrane electrode assembly (MEA) (not shown). A gas diffusion layer (GDL) is disposed on the anode and the cathode. A bipolar plate (not shown) is disposed on the GDL. The electrically conductive bipolar plate serves as a current collector, for the drainage and for conducting the reaction gases.In the fuel cell unit 1, the fuel cells 4 are arranged between two clamping elements 18 as clamping plates 19. An upper clamping plate 20 rests on the uppermost fuel cell 4 and a lower clamping plate 21 rests on the lowermost fuel cell 4. The clamping elements 18 apply a compressive force to the fuel cells 4, i.e. the upper clamping plate 20 is applied with a compressive force to the uppermost fuel cell 4 and the lower clamping plate 21 is applied with a compressive force to the lowermost fuel cell 4. The fuel cell stack 3 is thus braced in order to ensure the tightness for the fuel, the oxidizing agent and the coolant, in particular due to elastic seals, and in addition to keep the electrical contact resistance within the fuel cell stack 3 as low as possible. For clamping the fuel cells 4 with the clamping elements 18, four connecting devices 22 are formed on the fuel cell unit 1 as bolts 23, which are subject to tensile stress. The four bolts 23 are fixedly connected to the clamping plates 19.In the connection plate 15 and in the lower clamping plate 21, an opening for introducing recirculation fuel into the channels for recirculation fuel is formed. In addition, an opening for discharging recirculation fuel from the channels for recirculation fuel is formed in the connection plate 15 and in the lower clamping plate 21. In the terminal plate 15 and the lower clamping plate 21 as the clamping member 18, there are formed other openings for introducing oxidizing agent and discharging oxidizing agent, and unillustrated openings for introducing coolant and discharging coolant. Thus, a total of 6 openings are formed in the connection plate 15 and the lower clamping plate 21 (only partially shown in FIG. 1 ).A fuel cell system 2 includes, in addition to the fuel cell unit 1, an oxidant supply system 26 for supplying the fuel cell stack 3 with air as the oxidant. The oxidant supply system 26 comprises a gas delivery device 27, for example a blower, a compressor, a turbocompressor, which is driven by an electric motor and / or a turbine, and oxidant lines 28.In addition to the fuel cell unit 1, the fuel cell system 2 also comprises a fuel supply system 29 for supplying the fuel cell stack 3 with hydrogen as fuel. The fuel supply system 29 comprises a pressure vessel 30, a fuel line 31 as a process fluid line, valves (not shown) for fuel, in particular an injector (not shown) for controlling the volume flow of fuel introduced from the fuel line 31 into the recirculation line 32, a heat exchanger (not shown) for fuel, a pressure reducer (not shown), a recirculation fuel line 32 as a process fluid line, a recirculation fuel delivery device 33, an electric motor (not shown) for driving the recirculation fuel delivery device 33, and a water separator 34 for separating water from the recirculation fuel, a water container (not shown) for collecting the water collected in the water separator 34, a drain valve (not shown) for draining water from the water tank and a drain valve as a purge valve (not shown) for draining recirculation fuel to the environment. In the fuel supply system 29 for supplying the fuel cell stack 3 with hydrogen as fuel, the hydrogen stored in the pressure vessel 30 at a high pressure of, for example, 400 bar is supplied to the fuel cells 4 through the fuel line 31. After passing the fuel through the fuel cells 4, the hydrogen is not completely consumed, so that this hydrogen, which is discharged from the fuel cells 4, is fed back to the fuel cells 4 in a circuit through the recirculation fuel line 32. For conveying the recirculation fuel through the recirculation fuel line 32, the recirculation fuel conveying device 33 is used. After the fuel has been passed through the fuel cells 4, the moisture content of the fuel increases, so that, in order to avoid an excessively high water or moisture content in the recirculation fuel, the fuel supply system 29 has the water separator 34. The water separated in the water separator 34 is collected in the unillustrated water tank and discharged to the atmosphere through the drain valve (not illustrated). Excess recirculation fuel is discharged into the environment through the purge valve, not shown.In addition to the fuel cell unit 1, the fuel cell system 2 also comprises a cooling system (not shown) for tempering the fuel cell stack 3, i.e. for cooling the fuel cell stack 3. The coolant is conducted through channels for coolant in the bipolar plates of the fuel cells 4 and the heat at the heat exchanger is dissipated to the environment. In addition to the fuel cell unit 1, the fuel cell system 2 also comprises the oxidant supply system 26, the fuel supply system 29 and the cooling system, not shown, as a coolant supply system.The fuel cell unit 1 can also optionally be used and operated as an electrolysis cell unit 6 with modifications, in particular valves, which are not shown, i.e. forms a reversible fuel cell unit 1 or is configured to be operable only as an electrolysis cell unit 6. Some features which make possible the operation of the fuel cell unit 1 as the electrolysis cell unit 6 are described below. For electrolysis, a liquid electrolyte, namely strongly dilute sulfuric acid with a concentration of about c (H 2 SO 4) = 1 mol / l, is used. A sufficient concentration of oxonium ions H 30+ in the liquid electrolyte is necessary for electrolysis. FIG. 2 shows an electrolysis cell unit 6 which can only be used for electrolysis.The polarity of the electrodes takes place with electrolysis when operating as an electrolysis cell unit 6 in the opposite direction (not shown) as when operating as a fuel cell unit 1, so that hydrogen H 2 is formed at the cathodes in the channels for fuel through which the liquid electrolyte is conducted, and the hydrogen H 2 is absorbed by the liquid electrolyte and transported along in a dissolved manner. Analogously, the liquid electrolyte is conducted through the channels for oxidizing agents and oxygen O 2 is formed at the anodes or at channels for oxidizing agents. The fuel cells 2 of the fuel cell unit 1 function as electrolysis cells 9 during operation as electrolysis cell unit 6. the fuel cells 2 and electrolysis cells 9 thus form electrochemical cells 24. The hydrogen H 2 formed is taken up by the liquid electrolyte and carried along in dissolved form. The liquid electrolyte is stored in a storage container 35 and is conducted by a pump 37 and through electrolyte lines 36 through the channels in the electrolysis cell stack 8 or electrolysis cell stack 8 as electrochemical cell stack 10. For a reversible fuel cell unit 1 according to FIG. 1, which is not shown, two 3-way valves, which are not shown, are present on the recirculation fuel line 32 and the oxidant line 28 and are switched over during operation as the electrolysis cell unit 6, so that not recirculation fuel and oxidant but rather the liquid electrolyte is introduced from the storage container 35 into the recirculation fuel line 32 and the oxidant line 28 as the electrolyte line 36 by means of the pump 37. A separator 38 for hydrogen separates the hydrogen obtained from the electrolysis from the electrolyte. An oxygen separator 39 separates the oxygen recovered from the electrolysis from the electrolyte. The electrolyte is circulated through the electrolytic cell unit 6, and sulfuric acid is added according to consumption by an unillustrated apparatus. The electrolysis cell system 6 comprises, in addition to the electrolysis cell unit 6 with the electrolysis cell stack 8, also an electrolyte supply system 12. the electrolyte supply system 12 comprises the storage container 35, the electrolyte lines 36 and the pump 37 and also the separator 38 for hydrogen and the separator 39 for oxygen. A fuel cell unit 1 and an electrolytic cell unit 6 constitute an electrochemical cell unit 25 A fuel cell system 2 and an electrolytic cell system 7 constitute an electrochemical cell system 11.The oxidant supply system 26, the fuel supply system 29 and the coolant supply system of the fuel cell system 2 each form a subsystem 40 for the fuel cell unit 1. in an analogous manner, the electrolyte supply system 12 forms a subsystem 40 for the electrolysis cell unit 6. the subsystem 40 can also be formed as an electrical system for the electrochemical cell unit 25, for example with a battery and / or a transformer and / or an inverter.The subsystem 40 is installed within a subsystem housing 41. The subsystem housing 41 also includes a subsystem terminal plate 43 facing the housing 13 of the electrochemical cell unit 25. The components of the subsystem 40 are disposed within a subsystem interior 42. The subsystem interior 42 is bounded by the subsystem housing 41. The subsystem connection plate 43, which faces the electrochemical cell stack 10 and the electrochemical cell unit 25, has an opening 59. The subsystem housing 41 is fastened in a form-fitting and / or force-fitting manner to the housing 13, in particular to the connection plate 15, by means of a fastening device 46 as at least one subsystem fixing element 44. The at least one subsystem fixing element 44 is formed, for example, by a subsystem screw 45 and / or a subsystem bayonet connection. During the assembly of the electrochemical cell system 11, the subsystem 40 with the subsystem housing 41 is moved in a direction of movement 56 as an axial direction 57 towards the housing 13. This movement of the subsystem 40 with the subsystem housing 41 relative to the housing 13 of the electrochemical cell unit 25 is a relative movement on the one hand between the electrochemical cell unit 25 with the housing 13 and on the other hand between the subsystem 40 with the subsystem housing 41 The electrochemical cell unit 25 with the housing 13 can thus also be moved towards the subsystem 40 with the subsystem housing 41 and the subsystem 40 is subsequently fastened and fixed to the electrochemical cell unit 25, in particular the housing 13, by means of the fastening device 46.During assembly and movement of the subsystem 40 to the electrochemical cell unit 25, alignment and positioning of the subsystem 40 relative to the electrochemical cell unit 25 is necessary and this is accomplished with a centering device 47. The centering device 47 comprises a contact component 48 with a contact geometry 50 and a mating contact component 49 with a mating contact geometry 51 (FIGS. 3 to 5 ).FIG. 3 shows a first exemplary embodiment for the design of the centering device 47 and a seal 55. On the terminal plate 15 of the housing 13 of the electrochemical cell unit 25, a recess 52 is formed entirely circumferentially in a circumferential direction 58, and a protrusion 53 is formed on the subsystem terminal plate 43 of the subsystem housing 41. The protrusion 53 is formed fully circumferentially in the circumferential direction 58. The protrusion 53 forms the contact component 48 in this case. the cutout 52 is formed on the housing 13, i.e. the connection plate 15, so that a partial region of the connection plate 15 forms the mating contact component 49 on the cutout 52. The contact component 48 is thus formed integrally on the subsystem housing 41, i.e. the subsystem connection plate 43. The mating contact component 49 is formed integrally on the housing 13, i.e. the connection plate 15. A groove 54 is formed in the housing 13, i.e., the terminal plate 15, and the seal 55 is partially disposed in the groove 54. The groove 54 and also the seal 55 are formed completely circumferentially with respect to the opening 59 of the subsystem housing 41. Due to the size of the opening 59, the planar subsystem connection plate 43 is substantially annular or circumferentially formed to delimit the opening 58, and the seal 55 thus enables the opening 59 and the subsystem interior space 42 to be sealed with respect to the environment. The seal 55 thus lies on the housing 13, i.e. the connection plate 15, and on the subsystem housing 41, i.e. the subsystem connection plate 43. the contact component 48 lies with the contact geometry 50 on the mating contact geometry 51 of the mating contact component 49, and the direct contact between the contact geometry 50 and the mating contact geometry 51 is not illustrated in FIG. 3. The contact geometry 50 and the counter-contact geometry 51 are designed as a substantially planar surface and are aligned substantially parallel to the direction of movement 56 during assembly. During the assembly and fastening of the subsystem 41 to the housing 13 of the electrochemical cell unit 25, the contact geometry 50 formed completely in the circumferential direction 58 is thus to be placed on the counter-contact geometry 51 formed completely in the circumferential direction 58 and moved in the further movement direction in order to increase the contact area between the contact geometry 50 and the counter-contact geometry 51 until the subsystem housing 41 on the subsystem connection plate 53 rests on the elastic seal 55, for example made of rubber. Subsequently, the subsystem 40 is fastened to the housing 13 of the electrochemical cell unit 25 with the fastening device 46, so that the elastic seal 55 is arranged between the connection plate 15 and the subsystem connection plate 43 in an elastically prestressed manner with a compressive force. The seal 55 is an axial seal 55 because the bias of the seal 55 in the axial direction 57 with the compressive force is present.FIG. 4 shows a second exemplary embodiment of the centering device 47. In the following, substantially only the differences from the first exemplary embodiment according to FIG. 3 will be described. The groove 54 for receiving the packing 55 is formed on the protrusion 53 as the contact component 48 on the subsystem terminal plate 43 of the subsystem housing 41. The seal 55 bears directly on the mating contact geometry 51 of the mating contact component 49. The seal 55 is thus arranged, in particular in a direction perpendicular to the circumferential direction 58, between the contact geometry 50 and the counter-contact geometry 51. The seal 55 is arranged, in particular completely, between the contact component 48 and the mating contact component 49. The seal 55 is a radial direction 55 because the biasing and application of the compressive force to the seal 55 is in a radial direction 60 perpendicular to the axial direction 57. Between the contact geometry 50 and the counter-contact geometry 51 there is a direct contact, which is not shown for the sake of the drawings. In this case, the contact component 48 can be additionally and / or alternatively formed by the seal 55, with the result that the contact geometry 50 is formed by the region of the outer side of the seal 55 facing the mating contact component 49.FIG. 5 shows a third exemplary embodiment of the centering device 47. In the following, substantially only the differences from the first exemplary embodiment according to FIG. 3 will be described. The groove 54 for receiving the gasket 55 is formed on the subsystem housing 41 as the subsystem connection plate 43. The recess 52 is formed on the subsystem housing 41, i.e., the subsystem connection plate 43. A partial region of the subsystem housing 41 thus forms the mating contact component 49 with the mating contact geometry 51. the projection 53 is formed on the housing 13, i.e. on the connection plate 15, of the electrochemical cell unit 25, so that the contact component 48 is formed integrally on the housing 13. A partial region of the housing 13 on the projection 53 thus forms the contact component 48 with the contact geometry 50. the contact geometry 50 and the mating contact geometry 51 are planar and are oriented at an acute angle of approximately 45° to the axial direction 57. The contact geometry 50 and the counter-contact geometry 51 are thus aligned conically with respect to the axial direction 57. During the assembly and movement of the subsystem 40 with the subsystem housing 41 in the direction of movement 56 to the housing 13, the contact geometry 50 and the countercontact geometry 51 thus limit the movement of the subsystem 40 to the electrochemical cell unit 25 due to the conical design. In this case, the contact component 48 can be additionally and / or alternatively formed by the seal 55, with the result that the mating contact geometry 51 is formed by the region of the outer side of the seal 55 facing the contact component 48.FIG. 6 shows a section through the seal 55 perpendicular to the sectional planes of FIGS. 3 to 5 in a first exemplary embodiment. The seal 55 which is formed completely in the circumferential direction 58 with a circumferential angle α of 360° as a closed ring is of circular configuration. Due to this geometry of the seal 55, the contact component 48 and the counter-contact component 49 are also circular.FIG. 7 shows a section through the seal 55 perpendicular to the sectional planes of FIGS. 3 to 5 in a second exemplary embodiment. The seal 55 formed completely in the circumferential direction 58 with a circumferential angle α of 360° is formed in a rectangular shape. Due to this geometry of the seal 55, the contact component 48 and the counter-contact component 49 are also rectangular.FIG. 8 shows a section through the seal 55 parallel to the circumferential direction 58 in a third exemplary embodiment. The seal 55, which is partially formed in the circumferential direction 58 with a circumferential angle α of 90°, is formed in an L-shape. Due to this geometry of the seal 55, the contact component 48 and the mating contact component 49 are also partially formed in the circumferential direction 58 with a circumferential angle α of 90° and L-shaped.Viewed overall, the electrochemical cell system 11 according to the invention has significant advantages. The centering device 47, formed by the contact component 48 and the mating contact component 49, not only serves for aligning and positioning the subsystem 40 with the electrochemical cell unit 25, but additionally functions for arranging the seal 55. The seal 55 is arranged on and / or in the vicinity of the contact geometry 50 and / or the mating contact geometry 51, such that the machining and production of the contact geometry 50 and the mating contact geometry 51 in a machining step with a tool can be used to machine and produce the entire contact surface of the seal 55 in this machining step. This advantageously allows the costs to be reduced.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedEP 1 255 660 81

[0005] EP 2 497 142 B1

[0006]

Claims

Electrochemical cell system (11) having an electrochemical cell unit (25) for converting electrochemical energy into electrical energy as a fuel cell unit (1) and / or for converting electrical energy into electrochemical energy as an electrolysis cell unit (6), comprising - electrochemical cells (24) arranged in a stacked manner as a cell stack (10), - a housing (13) for the cell stack (24) and the cell stack (24) is arranged within the housing (13), - a subsystem (40) for the cell stack (24), - a fastening device (46) for fastening the subsystem (40) to the housing (13) of the cell stack (24), and the subsystem (40) is fastened to the housing (13) by the fastening device (46), characterized in that, the electrochemical cell unit (24) comprises a centering device (47) having a contact geometry (50) and a counter-contact geometry (51) for positioning the subsystem (40) relative to the housing (13) for the cell stack (10).Electrochemical cell system according to Claim 1, characterized in that the contact geometry (50) is formed on a contact component (48) and the mating contact geometry (51) is formed on a mating contact component (49), such that the centring device (47) is formed by the contact component (48) and the mating contact component (49).Electrochemical cell system according to Claim 2, characterized in that the contact geometry (50) is formed on a cutout (52) of the contact component (48) and / or the mating contact geometry (51) is formed on a projection (53) of the mating contact component (49).Electrochemical cell system according to Claim 2 or 3, characterized in that the contact geometry (50) is formed on a projection (53) of the contact component (48) and / or the mating contact geometry (51) is formed on a cutout (52) of the mating contact component (49).Electrochemical cell system according to Claim 3 or 4, characterized in that the cutout (52) is formed on the contact component (48) so as to be completely circumferential, in particular in the form of a ring.Electrochemical cell system according to Claim 4 or 5, characterized in that the projection (53) is formed on the mating contact component (51) so as to be completely circumferential, in particular in the form of a ring.Electrochemical cell system according to one or more of Claims 2 to 6, characterized in that the contact component (48) is formed at least partially, in particular completely, integrally with the housing (13) for the cell stack (10), and / or the mating contact component (49) is formed at least partially, in particular completely, integrally with a subsystem housing (41).Electrochemical cell system according to one or more of Claims 2 to 7, characterized in that the contact component (48) is formed at least partially, in particular completely, in one piece with the subsystem housing (41) and / or the mating contact component (51) is formed at least partially, in particular completely, in one piece with the housing (13) for the cell stack (10).Electrochemical cell system according to one or more of Claims 2 to 8, characterized in that the contact component (48) on the contact geometry (50) and the mating contact component (49) on the mating contact geometry (51) lie one on top of the other.Electrochemical cell system according to one or more of the preceding claims, characterized in that the contact geometry (50) and the counter-contact geometry (51) are aligned substantially parallel to a direction of movement (56) of the subsystem (40) during the assembly and fastening of the subsystem (40) to the housing (13) as an axial direction (57).Electrochemical cell system according to one or more of the preceding claims, characterized in that the contact geometry (48) and the counter-contact geometry (49) are oriented as an axial direction (57) at an acute angle to a direction of movement (56) of the subsystem (40) during the assembly and fastening of the subsystem (40) to the housing (13), such that the contact geometry (50) and the counter-contact geometry (51) are designed conically.Electrochemical cell system according to one or more of the preceding claims, characterized in that the contact geometry (50) and the counter-contact geometry (51) are formed to be complementary to one another, in particular planar.Electrochemical cell system according to one or more of Claims 2 to 12, characterized in that a seal (55) is formed between the contact component (48) and the mating contact component (49), in particular between the contact geometry (50) and the mating contact geometry (51).Electrochemical cell system according to Claim 13, characterized in that the seal (55) is formed so as to be completely circumferential, in particular ring-shaped.Electrochemical cell unit according to one or more of the preceding claims, characterized in that the contact geometry (50) and the counter-contact geometry (51) are formed in the circumferential direction (58) with a circumferential angle (α) of at least 30° or 90°, in particular completely circumferentially with a circumferential angle of 360°.

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