Fuel cell vehicle and detection system for identifying hydrogen in a fuel cell vehicle

Abstract

The invention relates to a detection system (10a; 10b; 10c) for detecting hydrogen (11) in a cavity (12) of a fuel cell vehicle (13) having a fuel cell system (15) with a fuel cell housing (16) and a purge air line (17) for purging the fuel cell housing (16), and a hydrogen sensor (14) outside the fuel cell housing (16), wherein the purge air line (17) has a purge air outlet (18) for discharging purge air (19) from the fuel cell housing (16), wherein the purge air outlet (18) is oriented for loading the hydrogen sensor (14) with purge air from the purge air line (17). Furthermore, the invention relates to a fuel cell vehicle (13) having a detection system (10a; 10b; 10c) according to the invention.

Description

Technical Field

[0001] This invention relates to a detection system for identifying hydrogen in the cavity of a fuel cell vehicle, comprising a fuel cell system and a hydrogen sensor. The fuel cell system includes a fuel cell housing and a purge air line for purging the fuel cell housing. The hydrogen sensor is located outside the fuel cell housing. The purge air line has a purge air outlet for discharging purge air from the fuel cell housing. Furthermore, this invention relates to a fuel cell vehicle having such a detection system. Background Technology

[0002] In a polymer electrolyte membrane (PEM) fuel cell system, hydrogen is converted into electrical energy with the help of oxygen in the presence of waste heat and water. For this purpose, such a PEM fuel cell system typically has multiple stacked fuel cell cells, each having: an anode supplied with hydrogen, a cathode supplied with air, and a polymer electrolyte membrane disposed between the anode and cathode. Stacking the fuel cell cells increases the output voltage of the fuel cell system. Within such a stack, there are supply channels that supply hydrogen and air to the individual fuel cell cells and remove consumed humid air and consumed anode exhaust gas from the fuel cell stack, or fuel cell system. Structurally, the fuel cell stack has a sealed section several meters long through which a small amount of hydrogen can leak out. To allow the escaped hydrogen to exit in a defined manner, the fuel cell stack according to the prior art is surrounded by a fuel cell housing. The fuel cell housing is supplied with purge air from at least one location in a defined manner. At at least one other location, the purge air exits the fuel cell housing through a purge air conduit. In essence, the fuel cell housing is purged by the purge air. To detect hydrogen in the fuel cell housing, in the case of the fuel cell system described at the beginning, a hydrogen sensor is installed in or on the purge air line. Additionally, by law, another hydrogen sensor must be installed in a closed or semi-closed cavity, such as the engine compartment of a fuel cell vehicle. In known systems, these two hydrogen sensors sense hydrogen, or hydrogen concentration, and shut down the fuel cell system when a predefined limit is detected. However, these hydrogen sensors are expensive and contribute to a complex system architecture in fuel cell vehicles. Summary of the Invention

[0003] The present invention provides a cost-effective and simply constructed system for reliably detecting unwanted hydrogen in fuel cell systems and / or fuel cell vehicles. Such a system is provided in particular by the detection system according to claim 1 and the fuel cell vehicle according to claim 10. Further advantageous embodiments are derived from the dependent claims, the specification, and the drawings. Here, the features described in conjunction with the detection system are also suitable for integration with the fuel cell vehicle according to the invention, and vice versa, so that the disclosure of various aspects of the invention is always mutually referenced and / or always able to be mutually referenced.

[0004] According to a first aspect of the invention, a detection system for identifying hydrogen in a cavity of a fuel cell vehicle is provided. The detection system includes a fuel cell system and a hydrogen sensor, the fuel cell system including a fuel cell housing and a purge air line for purging the fuel cell housing, the hydrogen sensor being located outside the fuel cell housing. The purge air line has a purge air outlet for discharging purge air from the fuel cell housing. The purge air outlet is oriented to load the hydrogen sensor with purge air from the purge air line.

[0005] By arranging the purge air line or purge air opening and the hydrogen sensor according to the invention, the hydrogen sensor, which is not commonly found outside the present invention, within the purge air line and / or fuel cell housing, can be eliminated. This reduces costs and simplifies the system architecture of the fuel cell system. By eliminating the hydrogen sensor and associated functional components, design space is also provided for other functional components or allows for a more compact design of the fuel cell system.

[0006] Preferably, the purge air outlet is oriented for directly loading the hydrogen sensor with purge air from the purge air line. That is, the purge air outlet and / or purge air line are configured and / or arranged such that the purge air discharged from the purge air line through the purge air opening can reach the hydrogen sensor in a straight path and / or at least without obstruction.

[0007] A hydrogen sensor can be understood as a sensor unit comprising a sensor housing and a sensor surface within the sensor housing. Therefore, the functional units arranged on the hydrogen sensor as described herein do not necessarily need to be arranged directly on the sensor surface, but can also be arranged on the sensor housing. The hydrogen sensor is configured and arranged for identifying hydrogen and / or hydrogen concentration in the purge air and the cavity.

[0008] The purge air outlet is configured to discharge purge air from the fuel cell housing into the surrounding environment of the fuel cell housing. Depending on the configuration variant, the purge air outlet can be understood as an end section of the purge air line or as a functional component connected to the purge air line that connects the purge air line to the hydrogen sensor.

[0009] The cavity can be configured as closed or semi-closed. The cavity can be understood as an installation space in a fuel cell vehicle, such as an engine installation space. The purge air line does not need to be configured with an ideal channel shape, but in principle can have any geometry, as long as it is suitable for effectively venting purge air from the fuel cell housing. The fuel cell system is not purged via the purge air line, but rather purged while using the purge air line. The purge air line can have a purge air inlet section and a purge air outlet section. The purge air is guided into the fuel cell housing through the purge air inlet section, and the purge air, or processed purge air, is vented back from the fuel cell housing using the purge air outlet section.

[0010] Preferably, the fuel cell system has multiple fuel cell stacks, which are surrounded or substantially surrounded by a fuel cell housing. The hydrogen sensor can be configured as a hydrogen microsensor with signal analysis and processing devices compensated for temperature, pressure, and air humidity.

[0011] Another possible configuration variation according to the invention is that, in the detection system, the purge air outlet is oriented towards the hydrogen sensor so that purge air from the purge air line can directly load the hydrogen sensor. By orienting the purge air outlet and purge air line directly towards the hydrogen sensor, the hydrogen concentration in the purge air can be determined particularly accurately. Mixing with other fluids can be easily prevented or at least reduced and / or adjusted to the desired amount. "Purge air outlet oriented towards hydrogen sensor" can be understood as the normal vector of the purge air outlet pointing towards and / or towards the hydrogen sensor. Furthermore, the normal vector of the purge air outlet can be orthogonal to or at an obtuse angle to the normal vector of the sensor surface of the hydrogen sensor, wherein the normal vector of the sensor surface, when installed in a fuel cell vehicle, extends along or substantially along the gravitational direction. Thus, it is possible to achieve, in a simple manner, that the purge air reaches the hydrogen sensor as directly as possible.

[0012] Another possible configuration variation according to the invention is that the detection system has a collection device for collecting hydrogen gas, which is arranged on the hydrogen sensor to guide the collected hydrogen gas to the hydrogen sensor. The collection device can also guide hydrogen-containing fluids (which would not reach the hydrogen sensor without it) to the hydrogen sensor, thereby enabling the detection system to detect unwanted hydrogen leaks particularly effectively.

[0013] In the detection system according to the invention, the collection device can be configured in a funnel shape. Due to the funnel shape, ambient air, and therefore possibly hydrogen, can be collected and guided to the hydrogen sensor in a simple, cost-effective, and efficient manner. The funnel-shaped collection device tapers towards the hydrogen sensor. In particular, when the detection system is installed in a fuel cell vehicle, the funnel-shaped collection device tapers against the direction of gravity. Preferably, the collection device is configured and / or arranged coaxially and / or concentrically with the hydrogen sensor and / or the purge air outlet.

[0014] In the detection system according to the invention, the purge air outlet is preferably arranged at least partially aligned with the hydrogen sensor. This allows the purge air flowing from the purge air conduit to directly encounter the hydrogen sensor. A particularly effective measurement of the hydrogen content in the purge air can be performed. In this case, the purge air outlet points directly or substantially directly at the hydrogen sensor. "The purge air outlet is arranged at least partially aligned with the hydrogen sensor" can be understood as an imaginary extension of the purge air conduit in the direction of the normal vector of the purge air outlet at least partially encountering the hydrogen sensor.

[0015] Furthermore, the detection system according to the invention can have a connecting housing that connects to the purge air line and the hydrogen sensor to guide the purge air to the hydrogen sensor. With the connecting housing, the purge air, and therefore the hydrogen in the purge air, can be directly guided to the hydrogen sensor, and the purge air will not, for example, bypass obstacles and thus will not undesirably mix with other fluids. With the connecting housing, the hydrogen sensor does not need to be directly arranged at the purge air outlet, and an effective measurement of the hydrogen content in the purge air can still be performed.

[0016] Furthermore, it is advantageous that the connecting housing is at least partially funnel-shaped in the detection system according to the invention. The funnel-shaped connecting housing, which preferably tapers towards the purge air outlet and correspondingly widens towards the hydrogen sensor, can serve as a diffuser, through which the purge air flow from the purge air line can be slowed down and thus more effectively detected on the hydrogen sensor.

[0017] Furthermore, in the detection system according to the invention, the connecting housing may have at least one air inlet for allowing hydrogen from the cavity to enter the connecting housing. This ensures, in a simple and effective manner, that hydrogen from the surrounding environment of the fuel cell housing, or leaked hydrogen from the fuel cell housing, can also be detected by the hydrogen sensor. The connecting housing preferably has multiple air inlets or orifices for allowing hydrogen from the cavity, or ambient air from the surrounding environment of the fuel cell housing, to enter the connecting housing. Alternatively, the connecting housing can be configured as a semi-shell, wherein the closed portion of the connecting housing connects the purge air line and the hydrogen sensor to each other, and the open portion of the connecting housing can be understood as the at least one air inlet.

[0018] Furthermore, it is possible that the purge air conduit of the detection system according to the invention has a nozzle, and the connecting housing has an injector adjacent to the nozzle, the injector having a mixing chamber for providing a fluid mixture formed by the purge air and hydrogen from the cavity, and a diffuser, wherein the mixing chamber has the at least one air inlet opening, and the diffuser is connected to the hydrogen sensor for delivering the fluid mixture to the hydrogen sensor. In this way, ambient air from the surrounding environment of the fuel cell housing, or hydrogen contained therein, can be efficiently drawn into the mixing chamber and further guided from there to the hydrogen sensor.

[0019] According to another aspect of the invention, a fuel cell vehicle is provided, having a cavity and a detection system for identifying hydrogen in the cavity, as described in detail above. Thus, the fuel cell vehicle according to the invention provides the same advantages as those described in detail with reference to the detection system according to the invention. The fuel cell vehicle is preferably provided as a road transport vehicle, particularly in the form of a passenger car or a truck.

[0020] Further improvements to the invention can be derived from the following description of various embodiments of the invention, which are schematically illustrated in the accompanying drawings. All features and / or advantages derived from the claims, specification, or drawings—including structural details and spatial arrangements—are key aspects of the invention, both individually and in various combinations. Attached Figure Description

[0021] The attached figures schematically illustrate:

[0022] Figure 1 This is a detection system according to a first embodiment of the present invention.

[0023] Figure 2 This is a detection system according to a second embodiment of the present invention.

[0024] Figure 3 The detection system according to the third embodiment of the present invention, and

[0025] Figure 4 It is a fuel cell vehicle equipped with a detection system according to a preferred embodiment of the present invention.

[0026] Components with the same function and mode of operation are respectively given the same reference numerals in the accompanying drawings. Detailed Implementation

[0027] Figure 1 This illustrates a method for identifying in accordance with a first embodiment. Figure 4 The diagram shows a hydrogen 11, or hydrogen content, detection system 10a, for the cavity fluid in the cavity 12 of the fuel cell vehicle 13. The detection system 10a includes a fuel cell system 15, which includes a fuel cell housing 16 and a purge air line 17 for purging the fuel cell housing 16. Furthermore, the detection system 10a has a hydrogen sensor 14 outside the fuel cell housing 16. (As shown in...) Figure 1 As shown, the purge air line 17 has a purge air outlet 18 for discharging purge air 19 from the fuel cell housing 16. The purge air outlet 18 is oriented to load the hydrogen sensor 14 with purge air from the purge air line 17. More precisely, to directly load the hydrogen sensor 14 with purge air from the purge air line 17, the purge air outlet 18 is directed towards the hydrogen sensor 14. (As shown in...) Figure 1 As can be seen, the purge air outlet 18 is arranged separately from the collection device 20 and the hydrogen sensor 14, so that hydrogen 11 from the cavity 12 or hydrogen-containing fluid outside the purge air line 17 can also reach the hydrogen sensor 14.

[0028] according to Figure 1 In the embodiment shown, the detection system 10a has a collection device 20 for collecting hydrogen or ambient air containing possible hydrogen from the surrounding environment of the fuel cell housing 16. The collection device 20 is arranged on the hydrogen sensor 14 to guide the collected hydrogen or ambient air to the hydrogen sensor 14. (As shown in...) Figure 1 As shown, the collecting device 20 is funnel-shaped, with the funnel shape tapering towards the hydrogen sensor 14. Furthermore, as can be seen from the illustrated embodiment, the purge air outlet 18 is arranged in alignment with the hydrogen sensor 14. An outlet opening (not shown) is preferably configured on the hydrogen sensor 14 and / or on the collecting device 20 for discharging or draining hydrogen 11 and / or purge air 19 from the hydrogen sensor 14. This prevents fluid congestion at the hydrogen sensor 14, which would lead to erroneous hydrogen detection.

[0029] exist Figure 2 The diagram shows a detection system 10b according to a second embodiment. The detection system 10b shown has a connection housing 21 that connects to a purge air line 17 and a hydrogen sensor 14 to guide purge air 19 to the hydrogen sensor 14, and... Figure 2 On the right side, the detection system 10b has an outlet opening for discharging purge air 19 and hydrogen 11 from the connecting housing 21. The connecting housing 21 is funnel-shaped. Furthermore, the connecting housing 21 has an inlet opening 22 for allowing hydrogen 11, or ambient air, from the cavity 12 along with the hydrogen contained therein to enter the connecting housing 21. Figure 2 The connecting housing 21 shown can also be considered as part of the purge air line 17.

[0030] exist Figure 3 The diagram illustrates a detection system 10c according to a third embodiment. In the illustrated detection system 10c, the purge air conduit 17 has a nozzle 23. The connecting housing 21 has an injector 24 adjacent to the nozzle 23, the injector having a mixing chamber 25 for providing a fluid mixture 27 and a diffuser 26, the fluid mixture 27 comprising purge air 19 and hydrogen 11 from a cavity 12. Therefore, an air inlet 22 is configured in the mixing chamber 25, and the diffuser 26 is connected to the hydrogen sensor 14 to deliver the fluid mixture 27 to the hydrogen sensor 14. Figure 3 The injector 24 shown can also be considered as part of the purging air line 17. Alternatively, the nozzle 23 can be considered as part of the injector 24. As in Figure 2 The connecting housing 21 shown in the figure, in Figure 3 The connecting housing 21 shown also has an outlet opening for discharging purge air 19 and hydrogen 11 from the connecting housing 21.

[0031] exist Figure 4 The diagram shows a fuel cell vehicle 13, which has a cavity 12 in the form of an engine mounting space and as shown in the diagram. Figure 1 The detection system 10a shown is used to identify hydrogen gas 11 in cavity 12.

[0032] In addition to the embodiments shown, the present invention allows for other design principles. That is, the invention should not be considered limited to the embodiments illustrated with reference to the accompanying drawings. The purge air line 17 does not necessarily extend beyond the fuel cell housing 16, but may also terminate in a line aligned with the fuel cell housing 16.

Claims

1. A detection system (10a; 10b; 10c) for identifying hydrogen (11) in a cavity (12) of a fuel cell vehicle (13), comprising a fuel cell system (15) having a fuel cell housing (16) and a purge air line (17) for purging the fuel cell housing (16), and a hydrogen sensor (14) outside the fuel cell housing (16), wherein the purge air line (17) has a purge air outlet (18) for discharging purge air (19) from the fuel cell housing (16), characterized in that the purge air outlet (18) is oriented for loading the hydrogen sensor (14) with purge air from the purge air line (17), the detection system has a connection housing (21) which is connected with the purge air line (17) and the hydrogen sensor (14) to direct the purge air (19) to the hydrogen sensor (14), the connection housing (21) has at least one intake opening (22) for hydrogen (11) from the cavity (12) into the connection housing (21), the purge air line (17) has a nozzle (23) and the connection housing (21) has a sparger (24) adjoining the nozzle (23), the sparger having a mixing chamber (25) for providing a fluid mixture (27) formed from purge air (19) and hydrogen (11) from the cavity (12) and having a diffuser (26) connected with the hydrogen sensor (14) for delivering the fluid mixture (27) to the hydrogen sensor (14).

2. The detection system (10a) according to claim 1, characterized in that the purge air outlet (18) is directed at the hydrogen sensor (14) for directly loading the hydrogen sensor (14) with purge air from the purge air line (17).

3. The detection system (10a) according to claim 1 or 2, characterized in that a collecting means (20) for collecting hydrogen is provided, which is arranged on the hydrogen sensor (14) for guiding the collected hydrogen to the hydrogen sensor (14).

4. The detection system (10a) according to claim 3, characterized in that the collecting means (20) is configured funnel-shaped.

5. The detection system (10a) according to claim 1 or 2, characterized in that the purge air outlet (18) is at least partially arranged in alignment with the hydrogen sensor (14) in a line.

6. The detection system (10b; 10c) according to claim 1 or 2, characterized in that the connection housing (21) is at least partially configured funnel-shaped. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 7. A fuel cell vehicle (13) having a cavity (12) and a detection system (10a; 10b; 10c) for identifying hydrogen gas (11) in the cavity (12) according to any one of the preceding claims.

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