WO2011141307A1

WO2011141307A1 - Modular fuel cell system

Info

Publication number: WO2011141307A1
Application number: PCT/EP2011/056916
Authority: WO
Inventors: Thomas Zeller; Dr. Christian Koerber; Bernhard Brüne
Original assignee: Trumpf Werkzeugmaschinen Gmbh + Co. Kg
Priority date: 2010-05-12
Filing date: 2011-05-02
Publication date: 2011-11-17
Also published as: DE102010028961A1

Abstract

A modular fuel cell system (1) comprises a plurality of fuel cell units (2), a support structure (3) to which the fuel cell units (2) are fastened independently of each other, and a central medium channel system (10) to which the fuel cell units (2) are connected independently of each other. The central medium channel system (10) is at least partially located in the support structure (3) and each fuel cell unit (2) is connected to the central channel system (10) by at least one connecting channel (24), said connecting channel being led through the wall section (7) of the support structure (3) which the respective fuel cell unit (2) covers.

Description

Modular fuel cell system

The invention relates to a modular fuel cell system with a plurality of fuel cell units, a support structure to which the fuel cell units are attached independently of each other, and a central media Kanaisystem to which the fuel cell units are connected independently.

From DE 10 2008 015 350 A1 a fuel cell system in the form of a modular fuel cell stack is known. A rack designed as a rack is provided for receiving individual fuel cells. At least one inside of the rack is provided with a supply rail. The supply rail has individual supply lines for the fuel cells. The fuel cells can be inserted into the rack and supplied with operating media separately via the supply lines.

In US 7,323,270 a rnodulares fuel cell system of the type mentioned is also described. The fuel cell system comprises four fuel cell stacks mounted on a cylindrical carrier plate are attached. In the space between the Brennstoffzellenstapein a central channel system for supplying the fuel cell stack is provided with operating media, which has individual connection pipes to which the fuel cell stacks are each connected separately.

The invention has set itself the goal of further developing a conventional fuel cell system in such a way that results in a modular fuel cell system that is characterized by a particularly compact design.

According to the invention, the object is achieved by a modular fuel cell system having the features of claim 1.

For the purposes of the invention, the central media channel system is at least partially disposed within the support structure, wherein the fuel cell units are each connected by means of at least one connection channel to the central channel system, which is guided through that wall portion of the support structure through which the connected by means of the connecting channel Fuel cell unit covered. The result is a compact fuel cell system with a support structure in which at least part of the central channel system is integrated to save space.

According to the invention, the support structure is provided with mutually independent coupling Schnittsteiien for the fuel cell units, to which the fuel cell attached and on soft they are also connected to a central duct system. In particular, it is not necessary in the construction of the fuel cell system to lead individual connection pipes or the like by an additional space between the fuel cell units to the fuel cell units. The connection of the fuel cell units takes place by means of connection channels. len, which are guided from the interior of the support structure in each case to a coupling interface on the support structure. In this case, the connecting channel passes through a wall portion of the support structure, which is associated with the respective coupling interface.

The support structure can be constructed in various ways. In particular, it may comprise a housing or a base body, which are designed as sheet metal or profile construction or as extruded profile. Within the housing or the body are media z. B. led via hoses or pipes to the defined coupling Schnittstelfen. Additionally or alternatively, the media may also be guided in a channel structure, which are introduced into a solid base body, in the interior of the support structure. The solid construction usually builds more compact, the leadership of the media on hoses or pipes material-saving constructions allowed, which can thus be cheaper and easier.

In order to accommodate at least a portion of the central channel system, the support structure, at least in the coupling region of the fuel cell units on a sufficient space. In the case of a profile construction, the required installation space for the central channel system can be elegantly integrated into cavities, recesses, etc. in the load-bearing profile construction. Preferably, the support structure itself may be modular.

The inventive design of the Koppiungs interfaces for the fuel cell units also results in a simple replacement of individual fuel cell units. Each fuel cell unit can be installed or removed independently of the other fuel cell units. In particular, the coupling interfaces can be designed as quick couplings. The central channel system can be used to supply process gases, such. As hydrogen or compressed air serve. The central duct system can also be used to remove gases generated in the fuel cell units, such as. B, steam, or for discharging unreacted process alley serve. Finally, a cooling medium for cooling the fuel cell units can be supplied and removed via the central channel system.

Further advantageous embodiments of the invention will become apparent from the characterizing features of claims 2 to 7.

By a particularly compact design, a fuel cell system is characterized in which the support structure has a support platform to which the fuel cell units are attached.

Preferably, fuel cell units are attached to different sides of the support structure. This measure results in a fuel cell system with expanded design options. In particular, the fuel cell units with different orientation relative to the support structure can be attached.

In a particularly preferred variant of the invention, fuel cell units are mounted on opposite sides of the support structure. The support structure is thus arranged at least in the coupling region of the fuel cell to save space between the fuel cell unit.

In the case of an advantageous development of the invention, the support structure has at least one central media channel, from which the Branch duct for the fuel cell units branch off. The result is a simply structured channel system,

Preferably, the connection channels are provided with separately controlled closure means which make it possible to connect or disconnect individual fuel cell units. The control of the closure means may, for. Passively, d. H. when falling below a flow rate, the closure means are automatically z. B, actuated by a spring element or gas pressure. For example, a defective fuel cell unit can be shut down by means of the controlled closure means, wherein the fuel cell system can continue to operate until the defective fuel cell unit is replaced.

Benefits also arise when starting the fuel cell system. Thus, one or more fuel cell units may have special cold-start properties. These can be initially operated without the remaining fuel cell units when starting the fuel cell system, which can be preheated by the waste heat of the start cell and then added gradually.

A particularly compact design embodiment results from the fact that a central media channel runs within the support structure along the fuel cell units in a plane, wherein the connection channels for the fuel cell units each branch perpendicular to this plane from the central media channel,

The fuel cell units may include single fuel cells and / or fuel cell stack. Preferably, the fuel cell units are designed as Brennstoffzellenstapei, each attached via one of its end faces to the support structure and connected to the central channel system. In the following, an exemplary embodiment of the invention will be explained by way of example with reference to schematic drawings. Show it :

1: a moduiares fuel cell system without housing,

2 shows a detail of the fuel cell system in a sectional representation,

3 shows a further section of the fuel cell system in one

Sectional view

4 shows a detail of an edge region of the fuel cell system in a sectional view,

5 shows a section of an edge region of the fuel cell system in a perspective view and

Fig. 6: an end face of the support structure in a sectional view.

FIG. 1 shows a modular fuel cell system 1 with four fuel cell units 2. The compact fuel cell system 1 is particularly suitable for mobile applications, e.g. As in automobiles, provided. The Brennstoffzeliensystem 1 has a housing, which is omitted but for reasons of clarity in Figure 1. The fuel cell units 2 are fastened independently of one another on a support structure designed as a support platform 3. On the two longitudinal sides 4 of the support platform 3 are two fuel cell units 2 along the longitudinal axis 5 of the support platform 3 are attached side by side. The fuel cell units 2 have connection plates 6, by means of which they are fastened to the support platform 3. The connecting plates 6 each cover a substantially rectangular wall section 7 of the support platform 3. These rectangular wall sections 7 each define a separate coupling interface 8 for a fuel cell unit 2. Thus, four defined coupling interfaces 8 are provided on the circumference of the support platform 2.

FIG. 2 shows a sectional view of the fuel cell system 1 along a sectional plane which runs perpendicular to the longitudinal axis 5 and centrally through a fuel cell unit 2. The support platform 3 is essentially formed by a profile construction 9. Within the support platform 3 a plurality, along the longitudinal axis 5 of the support platform 3 (in Figure 2 perpendicular to the plane) and in the plane of Tragpiatt- form 3 extending, central longitudinal channels are provided. The longitudinal channels are parts of a central channel system 10, which serves for the supply and removal of process gases and a cooling medium. In the exemplary embodiment shown, the fuel cell units 2 have hydrogen-oxygen fuel cells. Therefore, by means of the central channel system 10, hydrogen, compressed air and a cooling medium are supplied and removed.

For example, serve the two outer longitudinal channels 11, 12 of the air supply. The inwardly following longitudinal channels 13, 14 serve z. B. the removal of unreacted air. Furthermore, for example, the longitudinal channels 15, 16 are provided for supplying a cooling medium, the longitudinal channels 17, 18 for discharging a cooling medium. Finally, two longitudinal channels 19, 20 for removing hydrogen and a single longitudinal channel 21 for supplying hydrogen may be provided. The fuel cell units 2 are each connected by means of a plurality of connecting channels 24 to the central channel system 10. The connecting channels 24 branch off perpendicularly to the plane of the supporting platform 3 from the longitudinal channels 11 to 21 and are respectively guided through that wall section 7 of the supporting platform 3, which is covered by the fuel cell unit 2 connected by means of the connecting channels 24. In particular, the fuel cell units 2 abut with their connection plates 6 against the wall sections 7, through which the connection channels 24 are guided. At the transition between the support platform 3 and the fuel cell unit 2, the connection channels z. B. sealed by means not shown sealing elements.

FIG. 2 shows only the two connection channels 24 that run in the illustrated sectional plane. Other connection channels 24 extend in planes that are parallel to the section plane shown. The central longitudinal channels 11 to 21 are partially connected via two connecting channels 24 with a fuel cell unit 2, which follow one another along the longitudinal axis 5 of the support platform 3.

The connecting channels 24 are provided with closure means, not shown, which are actuated independently of one another. For example, the closure means close self-controlled by the media flow. In this way, a defective fuel cell unit 2 can be shut down while the other fuel cell units 2 can continue to operate. If necessary, one or more fuel cell units 2 can also be equipped with special cold start properties. When starting the fuel cell system 1, these fuel cell units 2 can then be put into operation first and the others are switched on only gradually. The connection plates 6 of the fuel cell units 2 are each constructed from two mutually superposed partial elements 25, 26. At the parting line 27 of the partial plates 25, 26 open at least part of the connecting channels 24 in transverse channels 28 which are incorporated in the partial plate 26. The transverse channels 28 run within the sub-plate 26 to edge regions of the fuel cell units 2. There open the transverse channels 28 in longitudinal channels 29, which are guided in the (passive) edge regions of the fuel cell units 2. The transverse and longitudinal channels 28, 29 are only indicated in FIG.

FIG. 3 shows a connecting plate 6 and, in sections, another connecting plate 6 in a view from the direction of the fuel cell units 2, d. H. on the sub-plates 26. The connecting plates 6 are each with six connecting elements 31 z. B. attached in the form of fastening screws on the Tragpiattform 3. Other embodiments of connecting elements 31 in the manner of quick couplings, e.g.

Snap connections, but are also conceivable.

FIG. 3 shows a section of the housing 32 which surrounds the fuel cell system 1. As shown in FIG. 3, the housing 32 serves to seal the edge-side connecting channels 24. From FIG. 4 it can be seen that the housing 32 also serves to seal the peripheral central longitudinal channels 11, 12.

The fuel cell units 2 each have a fuel cell stack 33, which in turn comprises a plurality of membrane electrode assemblies 37 (FIG. 5) following each other along a stack axis 34, including associated media guide units. The fuel cell panels 33 are each fastened to the support platform 3 via one of their end faces 35 and connected to the central duct system 10. Thus, a fuel cell stack 33 is via a single coupling interface 8 attached to the support platform 3 and connected to the central channel system 10.

The course of the stacking axes 34 of the fuel cell stack 33 can be seen, for example, from FIG. Accordingly, the stacking axes 34 are perpendicular to the wall portions 7 of the coupling interfaces 8. The fuel cell stack 33 are summarized by means not shown tensioning between each of the connecting plate 6 and an outer end plate 36 to the individual fuel cell units 2.

Each membrane-electrode unit is associated with current lugs 40 (FIGS. 4 and 5), by means of which current generated in the membrane-electrode units 37 can be removed. The current lugs 40 project on one longitudinal side of the fuel cell stack 33 and follow one another along the stacking axis 34. In Figures 1 and 2, the current lugs 40 are omitted for clarity.

The fuel cell stacks 33 are designed as "open" fuel cell stacks 33, ie one of the process gases, here the compressed air, is supplied to the membrane electrode assemblies 37 from an ambient space 41 at least longitudinally surrounding the fuel cell stacks 33 and not specifically through individual channels 41 is bounded and sealed to the outside by the housing 32. Therefore, for example, the fixing screw 42 of the housing 32 shown in Fig. 3 is provided with a seal not shown.

FIG. 5 again illustrates the flow path 43 along which the compressed air is supplied to the individual membrane electrode assemblies 37 within the fuel cell system 1. The remaining media are guided by means of the longitudinal channels 29 (eg B, FIG. 2) in a passive edge region of the fuel cell stack 33. In comparison to a fuel cell system which has a single (large) fuel cell stack, in particular flow-related advantages result from the division into a plurality of partial stacks 33, which are coupled to the support platform 3. The partial stacks 33 are each lower than a corresponding total stack. Therefore, the longitudinal channels 29 in the passive edge regions of the sub-stacks 33 are shorter, whereby the flow resistance in the Längskanäien 29 is lower. The flow conditions are therefore better at the respective outer membrane electrode assemblies 37 in the case of the division into Teilstapei 33, ie the parasitic losses for the compression of the media are lower.

On the other hand, the flow cross sections of the Längskanäie 29 can be reduced in the sub-stacks 33 in Vergfeich to a total stack, since less process gas must be transported through the longitudinal channels 29. The individual sub-stacks 33 can therefore be constructed more compact. This means savings in space, the material used and thus savings in costs.

FIG. 6 shows by way of example a fitting 44 of the central channel system 10, which is arranged on an end face of the support platform 3 and is connected to the longitudinal channels 19, 20, 21. The fitting 44 has a two-part plates 45, 46 constructed end plate 47 and an operating element in the form of a provided with integrated sealing system valve 48. The longitudinal channels 19, 20, 21 are connected to the valve 48 via transverse channels 50 extending in a parting plane 49 between the partial plates 45, 46.

Claims

claims

1. Modular fuel cell system (1) with

a plurality of fuel cell units (2),

- A support structure (3) to which the fuel cell units (2) are independently attached, and

a central media channel system (10) on which the

Fuel cell units (2) are connected independently of each other,

characterized in that the central media channel system (10) is at least partially disposed within the support structure (3), wherein the fuel cell units (2) are each connected to the central duct system (10) by means of at least one connection duct (24) is guided through that wall portion (7) of the support structure (3) through which the respective fuel cell unit (2) overlaps.

2. fuel cell system (1) according to any one of the preceding claims, characterized in that the support structure comprises a support platform (3) to which the fuel cell units (2) are attached.

3. fuel cell system (1) according to any one of the preceding claims, characterized in that fuel cell units (2) on different sides (4) of the support structure (3) are attached.

4. fuel cell system (1) according to any one of the preceding claims, characterized in that fuel cell units (2) on opposite sides (4) of the support structure (3) are attached.

5. Fuel cell system (1) according to one of the preceding claims, characterized in that the support structure (3) has at least one central media channel (11 to 21), branch off from the connection channels (24) for the fuel cell units (2).

6. fuel cell system (1) according to any one of the preceding claims, characterized in that a central media channel (11 to 21) within the support structure (3) along the fuel cell units (2) extends in a plane, wherein the Verbindungsungska- channels (24) for the fuel cell units (2) each branch perpendicular to this plane from the central media channel (11 to 21).

7. Fuel cell system (1) according to any one of the preceding claims, characterized in that fuel cell units (2) fuel cell stack (33), preferably each attached via one of its end faces (35) to the support structure (3) and to the central channel system (10) are connected.