DE102010052704A1 - Ceramic assembly for use as e.g. gas-to-gas humidifier in anode gas branch in fuel cell system, has coupling device formed for coupling and decoupling of fluids into groups of flow channels of two ceramic components - Google Patents

Abstract

The assembly (1) has two ceramic components (2a-2d) comprising groups of flow channels (3) for guiding fluids e.g. gas and liquid. A coupling device (4) selectively connects one of the groups of flow channels of the two components with each other in a flow-optimized manner. The coupling device is formed for coupling and decoupling of the fluids into the other groups of flow channels of the two components. The coupling device is attached to a separation plate that separates the groups of flow channels. The plate has connection openings selectively attached to the flow channels.

Description

The invention relates to a ceramic assembly having at least a first and a second ceramic component, wherein the ceramic components each have a plurality of flow channels for guiding fluids, with a coupling device which a first group of the flow channels of the first ceramic component with a first group of the flow channels of the second ceramic component fluidically connects. The invention also relates to a fuel cell system with this ceramic assembly.

Ceramic assemblies with flow channels for guiding fluids are used, for example, in fuel cell systems as a gas-to-gas humidifier or heat exchanger. Here, the ceramic assembly fulfills the task of conditioning cathode gas or anode gas for the fuel cells of the fuel cell system in terms of temperature or moisture content. The conditioning is carried out by heat or moisture transfer from one fluid to another.

From the US 20020155328 A1 , which is probably the closest prior art, a method and an apparatus for humidifying working gases for a fuel cell is described. It is also mentioned in this document that the humidification of the working gases can be implemented by the use of humidifiers with monoliths.

The invention has for its object to propose an adaptable ceramic assembly and a fuel cell system with this ceramic assembly.

This object is achieved by a ceramic assembly having the features of claim 1 and by a fuel cell system having the features of claim 12. Preferred or advantageous embodiments of the invention will become apparent from the dependent claims, the following description and the accompanying drawings.

An object of the invention thus relates to a ceramic assembly comprising at least a first and a second ceramic component. The ceramic material of the ceramic components may be any type of ceramic, in particular technical ceramics, such as a ceramic of metal oxides, in particular aluminum oxide, zirconium oxide or cordierite, or of silicon carbide. Particularly preferably, the ceramic components are in one piece and / or implemented as a monolith. This design is particularly inexpensive to manufacture.

Both in the first ceramic component and in the second ceramic component, a plurality of flow channels is introduced. The flow channels are formed in a straight line running in a possible training, in other embodiments, it is also possible that these run in a curve or angled. The flow channels are in particular designed to guide fluids, for example gases or liquids. In particular, the flow channels are realized as microchannels with a typical diameter smaller than 2 mm.

The ceramic components are preferably porous, so that moisture can pass from a first flow channel into a second, in particular adjacent or adjacent flow channel.

A coupling device is provided, which fluidly connects or couples a first group of the flow channels of the first ceramic component with a first group of the flow channels of the second ceramic components. Thus, fluids which are guided in flow channels of the first group of the first ceramic component can be continued via the coupling device into the flow channels of the first group of the second ceramic component.

In the context of the invention it is proposed that the coupling device is designed for coupling and / or decoupling fluids into a second group of the flow channels of the first and / or the second ceramic component. The coupling device thus forms an interface between two ceramic components, which makes it possible to separate a medium from the second group of flow channels of the first and / or second ceramic component and, for example via a collector to the ceramic components supply or dissipate. With the invention, it is thus possible that a first fluid through the first group of flow channels through the ceramic assembly is performed and a second fluid via the coupling device in the second group of the flow channels can be introduced or removed. In particular, at each end of the ceramic components, such a coupling device or - for example, end side - arranged another means for coupling and / or decoupling fluids in the second group of flow channels of the first and / or the second ceramic component.

The invention provides the advantage that in coupled ceramic components in various ceramic components, the fluid in the second group of flow channels can be chosen arbitrarily. Thus, in different ceramic components different fluids and / or fluids with different parameters, such as. As temperature, pressure, moisture content and / or flow direction, in the second group of the flow channels be guided. The ceramic assembly according to the invention thus fluids can be used optionally.

In the case of more than two ceramic components, it is also possible to design a plurality of coupling devices such that a first coupling device is designed for coupling and / or decoupling fluids into the second group of flow channels and carries out the fluids in the first group of flow channels and a further coupling device is constructed opposite and is designed for coupling and / or decoupling fluids in the first group of flow channels and performs the fluids in the second group of flow channels.

In a particularly preferred embodiment, the flow channels of the first group of the first ceramic component are selectively connected to the flow channels of the first group of the second ceramic component. In particular, a selective connection is made by connecting flow channels n: n, where n represents an integer natural number. In the simplest and preferred case, the flow channels are connected 1: 1. However, it is also possible to connect the flow channels, for example 2: 2, 3: 3 or 4: 4, wherein in the latter case it is preferred that the flow channels to be connected are arranged square. In order to optimize the moisture transfer surface or heat transfer surface in ceramic assemblies designed as gas-to-gas humidifiers or heat exchangers, it is particularly advantageous if the flow of fluids, in particular gaseous media, takes place alternately in the two groups of flow channels. This means that it is preferred that exclusively flow channels are located in the immediate vicinity of a flow channel through which a medium A flows, through which another medium B flows. Ideally, the mass and / or heat transport can take place over all channel walls of the flow channel. With rectangular or square channel cross sections, this can be up to four channel walls.

In a preferred development of the invention, the coupling device is designed such that the flow channels of the second group of the first ceramic component are connected to a first interface and / or the flow channels of the second group of the second ceramic component are connected to a second interface. The interface is designed, in particular, as an externally accessible interface, so that fluids can be added or removed via this interface or interfaces. With this configuration, it is consequently possible to connect or uncouple a fluid in the second group of flow channels at the end of a ceramic component.

In a preferred, constructive realization of the invention, the coupling device has at least one separation plate which separates or separates the first and the second group of flow channels. In particular, the separation plate is designed to separate mixed or alternately arranged flow channels of the first and the second group.

In a preferred embodiment of the invention, the separation plate on connection openings, which are assigned in particular selectively to the flow channels of the adjacent ceramic component. In a practical embodiment it can be provided that the connection openings and / or the flow channels are arranged like a grid or matrix, in particular in columns and rows, wherein the grid dimension of the flow channels in the adjacent ceramic component and the grid dimension of the connection openings in the separation plate is chosen to be the same. In other words, the flow channels are fluidly extended by the separation plate. Of course, it is also possible that both the flow channels in the ceramic component as well as the connection openings in the separation plate have a different spatial distribution, but which allows a continuation of the fluids from the flow channels of the first and the second group through the separation plate.

In one development of the invention, the ceramic assembly comprises a sealing plate having a plurality of openings, wherein the openings are arranged congruently with the connection openings of the separation plate, which are associated with the flow channels of the first group. Functionally, the sealing plate allows fluids to flow through it, which are guided in the flow channels of the first group.

In contrast, it is preferably provided that the sealing plate for the flow channels of the second group forms a boundary of a media space, wherein via the media space, the input and / or decoupling of fluids in the second group of the flow channels can be done. Thus, the sealing plate forms a passage element for the flow channels of the first group and a limiting element for the flow channels of the second group.

Considering the seal and the separation plate as two spaced-apart plates, it is preferably proposed that the connection between the connection openings of the separation plate for the first group of flow channels and the openings in the sealing plate over a plurality of To realize tubes or hollow cylinders. The tubes or hollow cylinders thus form the extensions of the flow channels of the first group. The remaining space between the separation plate and the sealing plate, which is not occupied by the tubes or hollow cylinders, forms a part of the media space through which the input and / or outcoupling of fluids in the second group of flow channels can take place.

In a preferred embodiment of the invention, it is provided that a separation plate is arranged on both sides of the sealing plate. This ensures that the flow channels of the first group are looped through the coupling device and that on both sides of the sealing plate a media space (mit-) is formed, the input and / or decoupling of fluids in the second group of the first ceramic component or the second ceramic component allows.

In a preferred structural embodiment of the invention, the media space is closed by a scoop with the interface. The scoop is preferably formed as a funnel-shaped component, which forms the media space together with the sealing plate. For coupling and / or decoupling, the scoop has the interface, for example designed as a connecting piece or the like.

In a particularly preferred embodiment of the invention, the ceramic assembly is designed as a gas-to-gas humidifier and / or a heat exchanger for a fuel cell system. In this embodiment, further advantages of the invention show: To realize a gas-to-gas humidifier or heat exchanger, it is no longer necessary to use a very large ceramic body, but the gas-to-gas humidifier or the heat exchanger can at least two or more ceramic components are realized, which are connected via the coupling device. In particular, it is possible to selectively inject or disengage a fluid into the flow channels of the second group in each ceramic component.

Consequently, the invention also makes it possible for ceramic components connected via coupling devices to assume different functions. For example, it is possible for the working gas for fuel cells of the fuel cell system to be guided through the first group of flow channels and to allow fluids flowing in cocurrent or countercurrent per ceramic component to flow through the second group of flow channels.

In addition, it is also possible to combine ceramic components with metallic assemblies. Here, a ceramic component by a metallic assembly such. As a layer of metallic single plates stacked plate stack substituted. Particularly advantageous in this arrangement is that a needs-based material selection is possible, for. As ceramic, porous structures for mass transfer (eg., For the humidification of a fluid) and metallic materials with a very good thermal conductivity for heat exchange.

Another object of the invention is a fuel cell system for generating electrical energy, in particular for a mobile, characterized by a ceramic assembly according to one of the preceding claims or according to the preceding description. Preferably, the ceramic assembly is designed as a gas-to-gas humidifier and / or a heat exchanger in the anode or in the cathode gas branch. In this embodiment, for example, in the first group of flow channels the ambient air to be conditioned for feeding in the direction of the fuel cell and in the second group of the flow channels moist exhaust air from the fuel cells, so that a moisture transfer from the exhaust air to the supply air can take place. Further fields of application of the ceramic module can be seen, for example, in heat exchangers.

Further features, advantages and effects of the invention will become apparent from the following description of a preferred embodiment of the invention and the accompanying drawings. Showing:

1 a schematic three-dimensional representation of a ceramic assembly as a first embodiment of the invention;

2 a first embodiment of the operation of the ceramic assembly in the 1 ;

3 to 6 Further alternative methods for operating the ceramic assembly in the 1 ;

7 an exploded view of the ceramic assembly in the region of the coupling device in the 1 ;

8th a schematic three-dimensional representation of a detail in the region of the coupling device of the ceramic assembly in the 1 ;

9 a schematic plan view of the opened coupling device of the preceding figures to illustrate the advantages of tolerance compensation in the structure.

Corresponding or identical parts are each provided with the same or the same reference numerals.

The 1 shows a schematic three-dimensional representation of a ceramic assembly 1 , which in this example four ceramic components 2a includes, b, c and d. The four ceramic components 2a , b, c and d are parallelepiped-shaped and adjoin one another at their end faces, so that a row is formed.

The ceramic assembly 1 is designed as a gas-to-gas humidifier or as a heat exchanger, wherein in the ceramic components 2a -D a plurality parallel to the longitudinal extent of the ceramic components 2a -D running flow channels 3 are arranged. The flow channels 3 are in the ceramic components 2a -D grid-like or matrix-like arranged in columns and rows and each have a square opening cross-section of z. B. 1.2 mm × 1.2 mm. In the flow channels fluids, especially gases or liquids can be transported.

Between the ceramic components 2a -D are coupling devices 4 arranged, which - as will be explained below - a part of the flow channels 3 fluidically connect. At the coupling devices 4 are interfaces 5a , B arranged, which is a coupling and / or decoupling of fluids in another part of the flow channels 3 allowed.

A first embodiment of the fluidic coupling of the ceramic assembly 1 in the 1 is in the 2 shown in the form of a schematic longitudinal section. In the cut ceramic components 2a , b, c are line-like the flow channels 3 not drawn to scale. In a first group of flow channels I become the flow channels 3 between the ceramic components 2a , b, c - also called modules - via the coupling devices 4 continued. This extends the flow channels 3 the first group I over at least two, in particular all ceramic components 2a d.

A second group II of the flow channels 3 ends in each case in the region of the coupling device 4 and allows an exchange, in particular a coupling or decoupling of fluids in the flow channels 3 , For example, in the ceramic component 2a through the coupling device 4 a fluid in the second group II of the flow channels 3 coupled. On the other hand - coming from the left - with the same coupling device 4 from flow channels 3 the second group II of the ceramic component 2 B the fluid is decoupled. The coupling or decoupling takes place via the interfaces 5a . 5b ,

As will be explained later, each end of the ceramic components 2a -D through the coupling devices 4 media rooms 6 formed, which fluidically with the interfaces 5a respectively. 5b are connected and in the flow channels 3 the second group II of the adjacent ceramic component 2a , b, c or d. In the illustrated example, a medium A is going straight through three ceramic components 2a , b, c performed. A medium B is via the second group II of the flow channels 3 passed in countercurrent to the medium A and after flowing through a ceramic component 2a , b and c, respectively.

The 3 shows a method alternative to the representation in FIG 2 , wherein the media A and B in cocurrent through the ceramic components 2a -C. Again, the medium B after flowing through a single ceramic component 2a -C removed.

The 4 shows a further alternative, wherein the medium A again directly through three ceramic components 2a -C is directed. The medium B, however, alternately conducted in cocurrent or countercurrent to the medium A.

The 5 on the other hand shows a process alternative, wherein the medium A on the direct way through the three ceramic components 2a -C is guided. The medium B is passed in countercurrent to the medium A. Through the middle ceramic component 2 B a medium C is passed in cocurrent to the medium A.

In the alternative embodiment in the 6 the medium A is going straight through the three ceramic components 2a -C headed. The medium B is passed in countercurrent to the medium A. Through the middle ceramic component 2 B the medium C is passed in countercurrent to the medium A.

The 7 shows an exploded view of the coupling device 4 between two ceramic components, in this example 2a . 2 B , Starting from the left ceramic component 2a which is formed, for example, as a ceramic monolith structure, initially followed by a scoop 7 , which the fluid from the second group II of the flow channels 3 of the ceramic component 2a in the media room 6 collects and if necessary via the interface 5a exchanges. Then there is a separation plate 8th positioned the flow channels 3 sporadically.

Below is a sealing plate 9 arranged as the end plate the media rooms 6 for the second group II of the flow channels 3 co-forms. Mirror image of the aforementioned separation plate 9 is another separation plate 8th arranged, to which - also mirror-image - another scoop 7 followed.

The flow channels 3 of the ceramic component 2a (And the other ceramic components b-d) have square or rectangular openings (but would also be conceivable triangular openings), which are arranged like a grid or a matrix in columns and rows. The separation plate 8th has a variety of connection breakthroughs 10 on which on the openings of the flow channels 3 are coordinated. With a coupling of the separation plate 8th with the ceramic component 2a is thus some or all of the flow channels 3 selectively a connection breakthrough 10 assigned, leaving a flow channel 3 of the ceramic component 2a via a connection breakthrough 10 the separation plate 8th connected is.

While the openings of the flow channels 3 are formed rectangular or square, show the connection breakthroughs 10 a circular opening. After the ceramic components 2a , b are made, for example, by a primary molding or other form-forming process and subsequent sintering, are the positions of the flow channels 3 subject to tolerances. Due to the occurring tolerances, the individual flow channels 3 be deformed to a small extent in the opening cross-section or displaced in the entirety.

In the 9 are the geometric conditions of the different opening cross-sections of flow channels 3 and connection breakthroughs 10 schematized, wherein a 3-cross-3 matrix of connection breakthroughs 10 on a 3-cross-3 matrix of flow channels 3 graphically overlaid. The positions of the flow channels 3 are shown deformed due to tolerance or shifted. Characterized in that the opening surfaces of the round, in particular circular connection openings 10 smaller than the angular opening areas of the flow channels to be connected 3 are formed, resulting from the cross-sectional reduction in the transition from the square cross-section to a round cross-section tolerance compensation, so that all flow channels 3 over the separation plate 8th gas-tight and fluid-tight continued.

The sealing plate 9 has fewer openings 11 as connection breakthroughs 10 in the separation plate 8th or flow channels 3 in the ceramic component 2a on. The openings 11 are about tubes, hollow cylinders or generally fasteners 12 fluidically with the connection breakthroughs 10 and thus with the flow channels 3 the first group I coupled. In contrast, forms the sealing plate 9 for the flow channels 3 the second group II a limitation of the media room 6 , Fluids of the flow channels 3 Although the second group II occur through the connection breakthroughs 10 in the separation plate 8th through, however, the sealing plate can 9 not happen. Instead, the fluids or the medium accumulate in the media room 6 passing through the sealing plate 9 and the scythe 7 is formed. To the area between the sealing plate 9 and the separation plate 8th fluidically with the interior of the scoop 7 To connect, the separation plate has edge windows 13 on which in a circumferential groove 14 the scoop 7 end up. The groove 14 is in turn with the interface 5a fluidically connected.

After the sealing plate 9 follows again a separation plate 8th and a scoop 7 , which are mirror images of the others.

In the assembled state thus flow channels 3 of the first group I via the separation plate 8th , Fasteners 12 , Openings 11 , Fasteners 12 , the second separation plate 8th into the flow channels 3 the first group I of the ceramic component 2 B forwarded. On both sides of the sealing plate 9 on the other hand, media spaces are forming 6 for the flow channels 3 the second group II, the fluidic with the interfaces 5a or b are connected.

The 8th shows a detail, wherein it can be seen that the medium, which consists of the connection openings 10 exit, over the windows 12 in the scoop 7 and from there over the groove 14 into the interface 5a is directed.

LIST OF REFERENCE NUMBERS

1

ceramic assembly

2a-d

ceramic components

3

flow channels

4

coupling devices

5a-b

interfaces

6

media rooms

7

scoop

8th

separation plate

9

sealing plate

10

Connection breakthroughs

11

openings

12

fasteners

13

window

14

groove

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 20020155328 A1 [0003]

Claims (12)

Ceramic assembly ( 1 ) with at least a first and a second ceramic component ( 2a , b, c, d), wherein the ceramic components ( 2a , b, c, d) each have a plurality of flow channels ( 3 ) for guiding fluids (A, B, C), with a coupling device ( 4 ), which a first group (I) of the flow channels ( 3 ) of the first ceramic component ( 2a , b, c, d) with a first group (I) of the flow channels ( 3 ) of the second ceramic component ( 2a , b, c, d) fluidically connecting, characterized in that the coupling device ( 4 ) for coupling and / or decoupling fluids (B, C) into a second group of the flow channels (II) of the first and / or the second ceramic component ( 2a , b, c, d) is formed. Ceramic assembly ( 1 ) according to claim 1, characterized in that the coupling device ( 4 ) the flow channels ( 3 ) of the first group (I) of the first ceramic component ( 2a , b, c, d) with the flow channels ( 3 ) of the first group (I) of the second ceramic component ( 2a , b, c, d) selectively, in particular 1 to 1, connects. Ceramic assembly ( 1 ) according to claim 1 or 2, characterized in that the coupling device ( 4 ) the flow channels ( 3 ) of the second group (II) of the first ceramic component ( 2a , b, c, d) with a first interface ( 5a ) and / or the flow channels ( 3 ) of the second group (II) of the second ceramic component ( 2a , b, c, d) with a second interface ( 5b ) connects. Ceramic assembly ( 1 ) according to one of the preceding claims, characterized in that the coupling device ( 4 ) at least one separation plate ( 8th ) associated with the first and the second group (I, II) of flow channels ( 3 ) separates. Ceramic assembly ( 1 ) according to claim 4, characterized in that the separation plate ( 8th ) Connection breaks ( 10 ), in particular selectively the flow channels ( 3 ) of the adjacent ceramic component ( 2a , b, c, d) are assigned. Ceramic assembly ( 1 ) according to one of the preceding claims, characterized by a sealing plate ( 9 ) having a plurality of openings ( 11 ), wherein the openings ( 11 ) congruent with the connection breakthroughs ( 10 ) of the separation plate ( 8th ) are arranged, which the flow channels ( 3 ) are assigned to the first group (I). Ceramic assembly ( 1 ) according to claim 6, characterized in that the sealing plate ( 9 ) for the flow channels ( 3 ) of the second group (II) a limitation of a media room ( 6 ), whereby over the media space ( 6 ) the coupling and / or decoupling of fluids (B, C) into the second group (II) of the flow channels ( 3 ). Ceramic assembly ( 1 ) according to one of claims 4 to 7, characterized in that the connection between the connection breakthroughs ( 10 ) in the separation plate ( 8th ) for the first group (I) of flow channels ( 3 ) and the openings ( 11 ) in the sealing plate ( 9 ) via a plurality of connecting elements ( 12 ), in particular tubes or hollow cylinders. Ceramic assembly ( 1 ) according to one of the preceding claims, characterized in that on both sides of the sealing plate ( 9 ) a separation plate ( 8th ) is arranged. Ceramic assembly ( 1 ) according to one of claims 7 to 9, characterized in that the media room ( 6 ) over a scoop ( 7 ) with the interface ( 5a , b) is completed. Ceramic assembly ( 1 ) according to one of the preceding claims, designed as a gas-to-gas humidifier and / or as a heat exchanger for a fuel cell system. Fuel cell system according to one of the preceding claims, characterized by at least one ceramic assembly ( 1 ) according to any one of the preceding claims.

Images