Vehicle having a fuel cell system, and method for treating a fluid emerging from the fuel cell system

Abstract

A vehicle is provided having a vehicle front end in which a fuel cell system which has a fuel cell stack is arranged, which full cell system is, at a cathode side, connected at least directly to an exhaust-gas line through which a fluid emerging from the fuel cell stack can be discharged from the vehicle front end. The exhaust-gas system comprises a sorption system for the adsorption of a liquid of the fluid emerging from the fuel cell stack. The invention furthermore relates to a method for treating a fluid of a fuel cell system, which has a fuel cell stack, in a vehicle.

Claims

1. A vehicle, comprising: a vehicle front end; a fuel cell system having a fuel cell stack arranged at the vehicle front end; and an exhaust system including an exhaust-gas line connected at least indirectly to a cathode side of the fuel cell stack, wherein the exhaust system includes a sorption system for adsorbing a liquid of a fluid exiting the fuel cell stack through the exhaust-gas line, and wherein the exhaust system is configured to be adjusted to an adsorption configuration, in which the fluid and the liquid can be conducted to the sorption system and the liquid can be adsorbed by the sorption system, when a speed of the vehicle is less than a predetermined limit speed, and to be adjusted to a passage configuration, in which the fluid and the liquid can be discharged from the vehicle front end, when the speed of the vehicle is greater than the predetermined limit speed.

2. The vehicle according to claim 1 wherein, in the passage configuration of the exhaust system, the liquid adsorbed in the sorption system can be desorbed and discharged from the vehicle front end.

3. The vehicle according to claim 1 wherein the sorption system is arranged inside the exhaust-gas line, and the sorption system is mounted so that it can pivot between a first position, which puts the exhaust system into the adsorption configuration, and a second position, which puts the exhaust system into the passage configuration.

4. The vehicle according to claim 1 wherein the exhaust system comprises a bypass line which is connected to the exhaust-gas line and is routed out of the vehicle front end and in which an actuator is arranged, the actuator adjustable between a first position, putting the exhaust system into the adsorption configuration, and a second position, putting the exhaust system into the passage configuration.

5. The vehicle according to claim 1 wherein the fuel cell stack is connected at a cathode outlet end via a cathode exhaust-gas line to a humidifier, to which the exhaust system comprising the sorption system is at least indirectly connected at a humidifier outlet end.

6. The vehicle according to claim 1 wherein the sorption system includes sorption material applied to a perforated disk.

7. The vehicle according to claim 1 wherein the sorption system is permeable to a gaseous portion of the fluid exiting the fuel cell stack through the exhaust-gas line.

8. The vehicle according to claim 1, further comprising a heater configured to vaporize the liquid.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) Additional advantages, features and details are provided in the following description of embodiments and on the basis of the drawings. The following is shown:

(2) FIG. 1 is a schematic representation of a first embodiment of a vehicle according to the invention,

(3) FIG. 2 is a schematic illustration of a first embodiment of an exhaust system according to the invention in a vehicle,

(4) FIG. 3 is a schematic representation of a second embodiment of an exhaust system according to the invention in a vehicle,

(5) FIG. 4(a) is a section of the exhaust system of the first embodiment in an adsorption configuration,

(6) FIG. 4(b) is a section of the exhaust system of the first embodiment in a passage configuration,

(7) FIG. 5(a) is a section of the exhaust system of the second embodiment in an adsorption configuration, and

(8) FIG. 5(b) is a section of the exhaust system of the second embodiment in a passage configuration.

DETAILED DESCRIPTION

(9) FIG. 1 shows a schematic representation of the vehicle with a longitudinally extending vehicle body 1 comprising a vehicle rear end 22 and a vehicle front end 21. A fuel cell system 2 is arranged in the vehicle front end 21. The fuel cell system 2 comprises a fuel cell stack 3, not shown in FIG. 1, which is connected at the cathode side 21 at least indirectly to an exhaust-gas line 4. A fluid exiting the fuel cell stack 3 can be discharged through the exhaust-gas line 4 from the vehicle front end 21 and thus from the vehicle body 1. In the present case, the fluid can be discharged from the vehicle front end 21 of the vehicle laterally to the longitudinal direction.

(10) FIG. 2 shows a first embodiment of the exhaust system 8 according to the invention in a vehicle. On the cathode side, the cathode gas is routed through a compressor 11 driven by means of a drive 10 to a humidifier 6 via a dry feed line 12. In the humidifier 6, the cathode gas is humidified and conducted via a wet feed line 5 into the cathode chambers of the fuel cell stack 3. At the cathode outlet 7, unreacted cathode gas and product water are conducted via the cathode exhaust-gas line 9 to the humidifier 6. The cathode gas is humidified, among other things, with the product water in the humidifier 6 and conducted to the cathodes. In order to counteract an over-saturation of the humidifier 6, a portion of the unreacted cathode gas and of the product water is conducted out of the vehicle body 1 laterally to the longitudinal axis or to the longitudinal direction as a fluid via the exhaust-gas line 4.

(11) The exhaust-gas line 4 is to be regarded as part of an exhaust system 8, which comprises a sorption system 13 for adsorbing a liquid of a fluid exiting the fuel cell stack 3. In the present case, the sorption system 13 is formed as a perforated disk to which sorption material, for example in the form of bulk material, is applied. The exhaust system 8 is movable between an adsorption configuration and a passage configuration. In the adsorption configuration, the fluid flowing out of the cathode spaces and containing the liquid can be conducted to the sorption system 13. The liquid is thereby adsorbed by the sorption system 13. In the passage configuration, the fluid containing the liquid can be discharged from the vehicle front end 21, in the present case from the vehicle body 1, laterally to the longitudinal direction of the vehicle. The sorption system 13 may be additionally designed to desorb adsorbed liquid in the passage configuration, as a result of which it can likewise be conducted out of the front end 21 of the vehicle body 1.

(12) In the first embodiment, the sorption system 13 is arranged inside the exhaust-gas line 4 and is pivotably mounted between a first position 14 which shifts the exhaust system 8 into the adsorption configuration and a second position 15 which shifts the exhaust system 8 into the passage configuration.

(13) FIG. 4(a) shows a section of the exhaust system with the sorption system 13 in the first position 14. The exhaust system 8 here is in the adsorption configuration. The sorption system 13 may be designed and arranged in the exhaust-gas line 8 in such a way that, in the first position 14, an inner wall 16 of the exhaust-gas line 4 is circumferentially sealed. The sorption system 13 is thus pivoted into the flow cross-section of the exhaust-gas line 4 in such a way that no fluid can pass through circumferentially between the sorption system 13 and the exhaust-gas line 4. The fluid is thus forced to flow to the sorption system 13. The liquid in the fluid is adsorbed in the sorption system 13. The sorption system 13 may, however, be permeable to the gaseous part of the fluid.

(14) FIG. 4(b) shows a section of the exhaust system 8 in the passage configuration, in which the sorption system 13 is in the second position 15. The sorption system 13 is pivoted toward the inner wall 16 of the exhaust-gas line 4 and may bear against it. The exhaust-gas line 4 is thereby released for a flow-through of the fluid coming from the cathode spaces.

(15) FIG. 3 shows a second embodiment of the vehicle according to the invention, wherein the exhaust system 8 comprises a bypass line 17 which is connected to the exhaust-gas line 4 and routed out of the vehicle front end 21, in particular oriented laterally to the longitudinal direction of the vehicle body 1. An actuator 18 embodied as a valve is arranged in the bypass line 17. This is adjustable between a first position 19 which shifts the exhaust system 8 into the adsorption configuration and a second position 20 which shifts the exhaust system 8 into the passage configuration.

(16) A section of the exhaust system 8 of the second embodiment in the adsorption configuration is shown in FIG. 5(a). This shows the actuator 18 in a first position 19 closing the bypass line 17. In this case, the fluid is conducted to the sorption system 13, wherein its liquid is adsorbed. FIG. 5(b) shows the actuator 18 in the second position 20 releasing the bypass line 17. The fluid flowing out of the cathode spaces is conducted out of the vehicle front end 21 via the bypass line 17. The second position 20 of the actuator 18 thus corresponds to the passage configuration of the exhaust system 8. In addition, the adsorbed liquid can be desorbed using a heating element assigned to the sorption system 13 and also be discharged from the vehicle to the environment via the bypass line 17 and/or the exhaust-gas line 4. In this connection, the liquid can also be vaporized so that the vapor—instead of a liquid—is conducted out of the vehicle.

(17) In an embodiment which is not shown in detail, the actuator 18 is arranged in the exhaust-gas line 17 in such a way that the bypass line 17 is closed in the first position 19 of the actuator 18. However, the section of the exhaust-gas line 8 leading to the sorption system 13 and formed as a sorption line is open or accessible, so that liquid is adsorbed in the sorption system 13. In the second position 20 the bypass line 17 is opened or released, the sorption line being closed. The liquid adsorbed by the sorption system 13 is then desorbed and conducted via the exhaust-gas line 8 out of the vehicle front end 21, in particular laterally to the longitudinal direction of the vehicle body 1. In this case, the desorbed liquid can be vaporized by means of a heating element of the sorption system 13 which is not shown in detail, so that now the vapor—instead of a liquid—is discharged via the exhaust-gas line 8 to the environment.

(18) A method may proceed as follows: The liquid-containing fluid of the fuel cell system 2 is conducted to the exhaust system 8. The exhaust system 8 is put into the adsorption configuration when a predetermined or a predeterminable limit speed of the vehicle is not reached, so that the liquid of the fluid is adsorbed by the sorption system 13. However, no later than when the vehicle is at a standstill or the vehicle is stopping, the exhaust system 8 is shifted into the adsorption configuration. This process can be controlled, for example, by means of a controller, not shown in detail.

(19) In the first embodiment shown, the exhaust system 8 is put into the adsorption configuration by the sorption system 13 being pivoted into the flow cross-section of the exhaust-gas line 4 and thus moved into the first position 14. In the second embodiment shown, the exhaust system 8 is put into the adsorption configuration by closing the bypass line 17 by means of the actuator 18.

(20) When the vehicle exceeds a predetermined or predeterminable limit speed, the exhaust system 8 will be put into the passage configuration, as a result of which the fluid is discharged from the front vehicle 21, such as laterally to the longitudinal direction of the vehicle body 1 by means of the exhaust system 8. The liquid adsorbed in the sorption system 13 may be desorbed at the same time and discharged—e.g., as vapor—via a heating unit, not shown in detail.

(21) In the first embodiment, the exhaust system 8 is put into the passage configuration by pivoting the sorption system 13 inside the exhaust-gas line 4 into the second position 15. In the second embodiment, the exhaust system 8 is put into the passage configuration by opening or releasing the bypass line 17 by means of the actuator 18. Desorbed liquid and/or the fluid may here be conducted out of the vehicle front end 21 via the bypass line 17.

(22) In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.