Fuel cell device

Abstract

In order to provide a fuel cell device which can be produced simply and cost-effectively, it is proposed that the fuel cell device comprises the following: a plurality of fuel cell elements which are stacked one on top of another along a stacking direction and form a fuel cell stack; a clamping device for securing the fuel cell elements; a fluid guide unit for supplying fuel and/or oxidizer and/or coolant to the fuel cell elements and/or for removing fuel and/or oxidizer and/or exhaust gas and/or coolant from the fuel cell elements, wherein the clamping device comprises two or more crossmembers which extend at least approximately perpendicularly to the stacking direction, wherein in each case at least one crossmember is arranged at each end of the fuel cell stack, wherein the crossmembers can be drawn towards one another by means of clamping elements and the fuel cell stack can thereby be clamped between the crossmembers.

Claims

1. A fuel cell device, comprising the following: a plurality of fuel cell elements which are stacked one on top of another along a stacking direction and form a fuel cell stack; a clamping device for securing the fuel cell elements; a fluid guide unit for supplying fuel and/or oxidizer and/or coolant to the fuel cell elements and/or for removing fuel and/or oxidizer and/or exhaust gas and/or coolant from the fuel cell elements, wherein the clamping device comprises two or more crossmembers which extend at least approximately perpendicularly to the stacking direction, wherein in each case at least one crossmember is arranged at each end of the fuel cell stack, wherein the crossmembers are drawable towards one another by means of clamping elements and the fuel cell stack is thereby clampable between the crossmembers, and wherein the clamping device has at least two crossmembers for each of the two ends of the fuel cell stack and/or wherein the crossmembers are drawable towards one another by means of clamping rods.

2. The fuel cell device as claimed in claim 1, wherein the clamping rods are threaded rods.

3. The fuel cell device as claimed in claim 1, wherein the clamping elements run completely outside the fuel cell stack.

4. A fuel cell device, comprising the following: a plurality of fuel cell elements which are stacked one on top of another along a stacking direction and form a fuel cell stack; a clamping device for securing the fuel cell elements; a fluid guide unit for supplying fuel and/or oxidizer and/or coolant to the fuel cell elements and/or for removing fuel and/or oxidizer and/or exhaust gas and/or coolant from the fuel cell elements, wherein the clamping device comprises two or more crossmembers which extend at least approximately perpendicularly to the stacking direction, wherein in each case at least one crossmember is arranged at each end of the fuel cell stack, wherein the crossmembers are drawable towards one another by means of clamping elements and the fuel cell stack is thereby clampable between the crossmembers, and wherein the fuel cell stack is provided at one or at both of its ends with a respective end plate made from an electrically insulating material.

5. The fuel cell device as claimed in claim 4, wherein one end plate or both of the end plates comprises/comprise a flow guide for guiding oxidizer, fuel, exhaust gas and/or coolant, wherein fluid lines for guiding the oxidizer, fuel, exhaust gas and/or coolant are arranged and/or configured so as to be completely separate fluidically from the clamping device.

6. The fuel cell device as claimed in claim 4, wherein one end plate or both of the end plates each has/have a force transmission structure which transmits a force, which is applied by one or more of the crossmembers, to the fuel cell stack with a predetermined distribution of force, wherein the force transmission structure comprises a honeycomb structure and/or rib structure and/or supporting structure or is formed therefrom.

7. The fuel cell device as claimed in claim 4, wherein the one end plate or the two end plates each comprises/comprise a pickup receptacle for receiving one pickup unit each, by means of which electrical energy generated in the fuel cell stack is removable, wherein the one end plate or the two end plates electrically insulate the pickup unit arranged in each case thereon and the clamping device from each other.

8. The fuel cell device as claimed in claim 1, wherein the clamping device has one or two pressure distribution plates which abut directly against end plates of the fuel cell stack and on which the crossmembers indirectly or directly act.

9. The fuel cell device as claimed in claim 8, wherein the one or more pressure distribution plates is/are arranged in plate receptacles, which are formed substantially complementarily thereto, of the end plates and/or wherein the crossmembers act on the one or the two pressure distribution plates by means of in each case one or more spring elements.

10. The fuel cell device as claimed in claim 1, wherein fuel, oxidizer, exhaust gas and/or coolant are guidable, by means of an one end plate or two end plates along the stacking direction on at least one crossmember and/or on a pressure distribution plate of the clamping device.

11. A fuel cell device, comprising the following: a plurality of fuel cell elements which are stacked one on top of another along a stacking direction and form a fuel cell stack; a securing device for securing the fuel cell elements; a fluid guide unit for supplying fuel and/or oxidizer and/or coolant to the fuel cell elements and/or for removing fuel and/or oxidizer and/or exhaust gas and/or coolant from the fuel cell elements, wherein the securing device includes two or more crossmembers which extend at least approximately perpendicularly to the stacking direction, wherein the fluid guide unit comprises a basic body which comprises a plurality of fluid lines and connection points for the connection of supply lines and/or removal lines and/or additional components of the fuel cell device, wherein the plurality of fluid lines of the fluid guide unit are formed by recesses formed in the basic body and one or more cover elements covering said recesses, and wherein the basic body and the one cover element or the plurality of cover elements are adhered or connected to one another.

12. The fuel cell device as claimed in claim 11, wherein the basic body is of integral construction and/or wherein the basic body is configured as a plastics injection-moulded component.

13. The fuel cell device as claimed in claim 11, wherein the one cover element or the plurality of cover elements is/are arranged on a side of the fluid lines of the fluid guide unit that faces the securing device.

14. The fuel cell device as claimed in claim 11, wherein the basic body is covered on one side or both sides with respect to the stacking direction by means of in each case one or more cover elements.

15. The fuel cell device as claimed in claim 11, wherein the fluid guide unit comprises a plurality of fluid lines which each extend through the basic body, one or more cover elements and an end plate of the fuel cell stack and/or wherein the fluid guide unit or the basic body comprises one or more separating devices for separating liquids and/or solids from a gas flow, wherein one or more separating devices are moulded into the basic body and/or are formed by suitable shaping of the basic body.

16. The fuel cell device as claimed in claim 11, wherein the basic body comprises one or more valve receptacles for receiving one or more valve elements, and/or wherein the basic body comprises one or more sensor element receptacles for receiving one or more sensor elements.

17. The fuel cell device as claimed in claim 11, wherein the basic body comprises one or more supporting elements for stabilizing and/or reinforcing the basic body and/or the fluid guide unit.

18. The fuel cell device as claimed in claim 11, wherein the fluid guide unit or the basic body and/or one or more cover elements and/or one or more end plates of the fuel cell device have an at least partially after-treated surface.

19. The fuel cell device as claimed in claim 11, wherein the fluid guide unit comprises a thermally insulating portion by means of which the securing device and/or the fluid lines and/or one or more separating devices and/or one or more valve elements are thermally separated from the fuel cell stack.

20. The fuel cell device as claimed in claim 4, wherein the clamping device acts indirectly or directly on the one end plate or on the two end plates.

21. The fuel cell device as claimed in claim 11, wherein the basic body and the one cover element or the plurality of cover elements are adhered or connected to one another by plastics welding.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a schematic perspective illustration of a fuel cell device looking at an upper side of the fuel cell device;

(2) FIG. 2 shows a schematic perspective illustration of the fuel cell device from FIG. 1, looking at a lower side of the fuel cell device;

(3) FIG. 3 shows a schematic perspective exploded illustration of the fuel cell device from FIG. 1;

(4) FIG. 4 shows a schematic perspective exploded illustration of components of the fuel cell device from FIG. 1 that are arranged below a fuel cell stack of the fuel cell device;

(5) FIG. 5 shows a schematic top view of an upper side of the fuel cell device from FIG. 1;

(6) FIG. 6 shows a schematic vertical section through the fuel cell device from FIG. 1 along the line 6-6 in FIG. 5;

(7) FIG. 7 shows a schematic vertical section through the fuel cell device from FIG. 1 along the line 7-7 in FIG. 5;

(8) FIG. 8 shows a schematic vertical section through the fuel cell device from FIG. 1 along the line 8-8 in FIG. 5;

(9) FIG. 9 shows a schematic perspective illustration of a basic body of a fluid guide unit of the fuel cell device from FIG. 1, looking at a lower side of the basic body;

(10) FIG. 10 shows a schematic perspective illustration of the basic body from FIG. 9, looking at the upper side thereof;

(11) FIG. 11 shows a schematic top view of a lower side of the basic body from FIG. 9;

(12) FIG. 12 shows a schematic top view of an upper side of the basic body from FIG. 9;

(13) FIG. 13 shows a schematic side view of the basic body from FIG. 9; and

(14) FIG. 14 shows a further schematic side view of the basic body from FIG. 9.

(15) Identical or functionally equivalent elements are provided with the same reference signs in all of the figures.

DETAILED DESCRIPTION OF THE DRAWINGS

(16) An embodiment, which is illustrated in FIGS. 1 to 14, of a fuel cell device, denoted as a whole by 100, serves in particular for generating electrical energy by electrochemical conversion of fuel with oxidizer, for example hydrogen with atmospheric oxygen.

(17) The fuel cell device 100 comprises a plurality of fuel cell elements 102, for example 50, 100 or 200, which are stacked one above another in a stacking direction 104 and together form a fuel cell stack 106.

(18) The fuel cell elements 102 are sealed off here from the surroundings by means of a plurality of sealing layers 108.

(19) At both ends along the stacking direction 104 the fuel cell stack 106 borders on end plates 110 of the fuel cell device 100, wherein the end plates 110 are provided at both ends with a respective pickup unit 112 for removing electrical energy from the fuel cell stack 106.

(20) The pickup units 112 each comprise here a pickup sheet 114 which abuts in a sealing and at the same time electrically contacting manner against the fuel cell stack 106 via a sealing layer 108.

(21) Electric voltage is tapped off from a pickup sheet 114 via one or more pickup strips 116 and transmitted to one or more conducting pins 118.

(22) However, instead of conducting pins 118, other connections, plug-in connections, etc. can also be provided.

(23) It may be favourable if each pickup unit 112 has two obliquely, in particular substantially diagonally, mutually opposite pickup strips 116. By this means, optimized distribution of voltage in the fuel cell stack 106 and optimized thermal loading of the pickup unit 112 can be obtained.

(24) Each end plate 110 preferably comprises a pickup receptacle 120 for receiving one pickup unit 112 in each case.

(25) Each pickup receptacle 120 here comprises in particular one or more through holes for the passage of the conducting pin 118.

(26) As can be gathered in particular from FIGS. 1 to 3, the fuel cell device 100 furthermore comprises a housing 122 by means of which the fuel cell stack 106 is surrounded and protected against an external influence.

(27) The housing 122 is formed in particular by a hollow-cylindrical body with a substantially rectangular base area and extends from one end plate 110 to the further end plate 110.

(28) The housing 122 is preferably positioned and/or centred relative to the end plates 110 and/or relative to the fuel cell stack 106 by means of one or more centring caps 124 (see in particular FIGS. 1 and 2).

(29) As can be gathered in particular from FIGS. 1, 3 and 4, the fuel cell device 100 preferably comprises a securing device 126 for securing the fuel cell elements 102 relative to each other.

(30) In particular, the securing device 126 comprises a clamping device 128 by means of which the fuel cell elements 102 are pressed onto one another in the stacking direction 104.

(31) For this purpose; the clamping device 128 comprises in particular a plurality of crossmembers 130 which extend transversely, for example substantially perpendicularly, to the stacking direction 104, and therefore engage over and/or engage behind the fuel cell stack 106 and are drawable towards one another in the stacking direction 104 by means of clamping elements 132. The fuel cell stack 106 can therefore be clamped in particular between the crossmembers 130.

(32) A crossmember 130 can be, for example, of substantially diamond-shape design, wherein two mutually opposite ends in particular form receptacles for the clamping elements 132.

(33) In particular, a centring opening 134 which can be brought into engagement in particular with a centring projection 136 of an end plate 110 is arranged and/or formed substantially centrally in each crossmember 130.

(34) By this means, the crossmember 130 can be oriented simply and exactly relative to the end plate 110.

(35) It may be favourable if the clamping device 128 has two pairs of crossmembers 130, wherein in each case two clamping elements 132, are associated with each pair of crossmembers 130, and wherein in each case one crossmember 130 of each pair of crossmembers 130 is arranged at one end each of the fuel cell stack 106.

(36) The crossmembers 130 act in particular via a pressure distribution plate 138 on the end plate 110 and via the end plate 110 on the pickup unit 112 and finally on the fuel cell stack 106.

(37) To even out an introduction of force, one or more spring elements 140, for example disc springs 142, are preferably provided, which are arranged in particular between the respective crossmember 130 and the pressure distribution plate 138.

(38) One or more guide discs 144 preferably furthermore serve for positioning and/or centring the disc springs 142, in particular relative to the centring opening 134 and/or to the centring projection 136.

(39) As can be gathered in particular from FIG. 4, a single pressure distribution plate 138 is preferably provided for two crossmembers 130, wherein a separate disc spring 142 and a separate guide disc 144 is associated with each crossmember 130. Two centring projections 136 which are formed, for example, on the end plate 110 preferably position the pressure distribution plate 138, which has two centring openings 134 for this purpose, and the spring elements 140, the guide discs 144 and the crossmembers 130.

(40) The end plate 110 furthermore preferably comprises a plate receptacle 146 for receiving and/or positioning the pressure distribution plate 138.

(41) The plate receptacle 146 preferably comprises a force transmission structure 148 which in particular comprises or forms a honeycomb structure 150 or a supporting structure 152.

(42) A uniform introduction of force from the pressure distribution plate 138 to the pickup unit 112 and finally to the fuel cell stack 106 can be obtained in particular by means of the force transmission structure 148, in particular since the force transmission structure 148 can preferably be produced with smaller tolerances and therefore lower manufacturing inaccuracies.

(43) For this purpose, the entire end plate 110 including the force transmission structure 148 is formed in particular as a plastics injection-moulded component.

(44) The pressure distribution plate 138, the spring elements 140, the guide discs 144 and the crossmembers 130 are preferably formed from a metallic material.

(45) The clamping elements 132 are preferably also formed from a metallic material.

(46) In particular, the clamping elements 132 are clamping rods 154, for example threaded rods 156, onto which screw nuts 158 can be screwed at both ends in order ultimately to clamp the crossmembers 130 in place.

(47) The components of the clamping device 128 are preferably thermally and/or mechanically and/or spatially separated from the fuel cell stack 106 by means of the end plates 110 formed in particular from a plastics material.

(48) In particular, the force transmission structure 148 forms a thermally insulating portion 160.

(49) As can be gathered in particular from FIG. 4, the fuel cell device 100 furthermore comprises a fluid guide unit 162.

(50) The fluid guide unit 162 forms or comprises in particular a media module 164 for distributing media and/or guiding media.

(51) The fluid guide unit 162 in this case preferably comprises a basic body 166 which is illustrated separately in FIGS. 9 to 14.

(52) The basic body 166 is covered in particular by means of one or more cover elements 168, as a result of which in particular a plurality of fluid lines 170 and other cavities are formed in the fluid guide unit 162.

(53) The basic body 166 is preferably a plastics injection-moulded component like the cover element 168.

(54) The plastics injection-moulded components are preferably provided with numerous recesses 172 and/or raised portions 174 and/or passage openings 176, as a result of which ultimately the fluid line 170 is formed with predetermined shapes and dimensions.

(55) In particular, the basic body 166 comprises a plurality of connection points 178 on which, for example connectors 180 are mountable in order ultimately to be able to connect media lines to the fuel cell device 100 and to supply the media from outside the fuel cell device 100 to the fuel cell stack 106.

(56) For this purpose, the connection points 178 are provided in particular with fastening points 182 on which, for example, holding-down devices 184, plate anchors, etc. for securing connectors 180 or other components can be arranged.

(57) Furthermore, the basic body 166 preferably comprises one or more receptacles for other additional components and/or connections, for example electric connections.

(58) In particular, one or more sensor element receptacles 186 are provided for receiving sensor elements 188 (see in particular FIGS. 4 and 14).

(59) The sensor elements 188 are in particular pressure sensor elements and/or temperature sensor elements.

(60) As emerges in particular from FIG. 4, the basic body 166 and the cover element 168 covering the basic body 166 are arranged on a side of the crossmember 130 and of the entire clamping device 128 that faces away from the fuel cell stack 106.

(61) The mechanical fastening of the basic body 166 takes place here via the end plate 110 to which the cover element 168 is fixedly welded. The basic body 166 is fixedly welded in turn to the cover element 168.

(62) The end plate 110 preferably likewise comprises one or more fluid lines 170 which in particular form a flow guide 192.

(63) Each medium guided in the basic body 166 can preferably be guided past the clamping device 128 by means of the end plate 110 and supplied to the fuel cell stack 106. In particular, contact of the media with the components of the clamping device 128 can thereby be avoided, which ultimately minimizes heat transmission and chemical loading.

(64) As can be gathered in particular from FIGS. 10 and 12, the basic body 166 and therefore also the fluid guide unit 162 comprise a plurality of passage openings 176 and connection points 178 for the media supply of the fuel cell stack 106.

(65) In particular, the following components are provided in this connection: a coolant inlet 194, a coolant outlet 196, an oxidizer supply means 198, an oxidizer removal means 200, which in particular simultaneously forms an exhaust gas removal means 202, a fuel supply means 204 and a fuel removal means 206.

(66) The oxidizer supply means 198 is in particular an air inlet 208. The oxidizer removal means 200 is in particular an air outlet 210. The fuel supply means 204 is in particular a hydrogen inlet 212. The fuel removal means 206 is in particular a hydrogen outlet 214.

(67) The hydrogen is preferably guided in a circuit by means of a recirculation unit (not illustrated).

(68) An outlet of the circulation unit is preferably connected to the hydrogen inlet 212. An inlet of the recirculation unit is preferably connected to the hydrogen outlet 214.

(69) Furthermore, a plurality of supporting elements 216 are preferably integrated and/or moulded into the basic body 166.

(70) Supporting elements 216 are in particular supporting domes 218 and/or supporting ribs 220.

(71) One or more supporting elements 216 preferably serve firstly to mechanically stabilize the basic body 166, in particular by supporting and/or reinforcing walls of the basic body 166. Secondly, one or more supporting elements 216 can serve as separating elements of separating devices 222. For example, one or more separating devices 222 configured as droplet separators 224 are integrated in the basic body 166 or are formed by the same.

(72) For example, a droplet separator 224 for separating water can be arranged and/or formed downstream of the hydrogen outlet 214 (anode outlet) or therein.

(73) As an alternative or in addition thereto, a droplet separator 224 can be arranged and/or formed upstream of the hydrogen inlet 212 (anode inlet) or therein.

(74) Furthermore, one or more valve elements 226 and/or receptacles therefor can be integrated in the basic body 166.

(75) A valve element 226 can be, for example, a purge valve 228, a drainage valve 230 and/or a throttle nozzle 232.

(76) Different fluid lines 170 of the fluid guide unit 162 can be connected to one another here by means of the valve elements 226 in order to be able to control and/or regulate pressure conditions within the fluid guide unit 162 in a targeted manner and/or in order to be able to reliably remove separated fluid, in particular water.

(77) Furthermore, one or more valve elements 226 can be provided for flooding and/or flushing individual fluid lines 170 or the entire fuel cell device 100.

(78) As emerges in particular from FIG. 10, the raised portions 174 of the basic body 166 in particular form welding webs 234 which can be brought into engagement, in particular can be connected in an integrally bonded manner, to welding webs 234 corresponding thereto on the cover element 168.

(79) By means of the configuration of the basic body 166 as an integral plastics injection-moulded component, numerous functions can preferably be integrated into a single component or a single functional unit of the fuel cell device 100. By this means, the fuel cell device 100 can firstly be produced cost-effectively. Secondly, the number of interfaces can thereby be reduced, as a result of which in particular optimized sealing of the fluid guide unit 162 is obtainable.