Abstract
The invention relates to a fuel cell system (100) with at least one fuel cell (90), each fuel cell (90) having a cathode inlet (92), and with a housing (50) in which the at least one fuel cell (90) is arranged, the housing (50) having at least one ventilation inlet (52) through which at least one ventilation fluid flows in and at least one outflow outlet (54) through which at least one outflow fluid flows out. The fuel cell system (100) further comprises a supply line (14) to the at least one cathode inlet (92) for providing a supply fluid from a first fluid source to the at least one cathode inlet (14), and a compressor (16) in the supply line (14) for compressing the supply fluid. The fuel cell system (100) also comprises a fluidly communicating ventilation line (24) between the supply line (14) and the at least one ventilation inlet (52) for connecting the supply line (14) to the at least one ventilation line (52), the fluidly communicating ventilation line (24) being connected to the supply line (14) between the compressor (16) and the at least one cathode inlet (92), and/or a compressor cooling line (32) for cooling the compressor (16) and a fluidly communicating compressor ventilation line (34) between the compressor cooling line (32) and the at least one ventilation inlet (52) for connecting the compressor cooling line (32) to the at least one ventilation inlet (52).
Claims
1. A fuel cell system (100) with a) at least one fuel cell (90), wherein each of the at least one fuel cell (90) has a cathode inlet (92), b) a housing (50), in which the at least one fuel cell (90) is arranged, wherein the housing (50) has at least one ventilation inlet (52) for inflow of at least one ventilation fluid and at least one outlet (54) for the outflow of at least one outflow fluid, c) a supply line (14) to the cathode inlet (92) for providing a supply fluid from a first fluid source to the cathode inlet (92), and d) a compressor (16) in the supply line (14) for compressing the supply fluid, characterized in that the fuel cell system (100) further comprises: e) a fluidly communicating ventilation line (24) connecting the supply line (14) to the at least one ventilation inlet (52), wherein the fluidly communicating ventilation line (24) is connected to the supply line (14) between the compressor (16) and the at least one cathode inlet (92), and/or f) a compressor cooling line (32) for cooling the compressor (16) and a fluidly communicating compressor ventilation line (34) between the compressor cooling line (32) and the at least one ventilation inlet (52) for connecting the compressor cooling line (32) to the at least one ventilation inlet (52).
2. The fuel cell system (100) as claimed in claim 1, characterized in that a heat exchanger (42) is arranged in the supply line (14) between the compressor (16) and the at least one cathode inlet (92), and the fluidly communicating ventilation line (24) is connected to the supply line (14), which is situated between the heat exchanger (42) and the at least one fuel cell (90).
3. The fuel cell system (100) as claimed in claim 1, characterized in that a humidifier (44) is arranged in the supply line (14) between the compressor (16) and the at least one cathode inlet (92), and the fluidly communicating ventilation line (24) is connected to the supply line (14), which is situated between the humidifier (44) and the at least one fuel cell (90).
4. The fuel cell system (100) as claimed in claim 1, characterized in that the fluidly communicating ventilation line (24) has a mass-flow sensor (46a) between the supply line (14) and the at least one ventilation inlet (52), and/or in that the fluidly communicating compressor ventilation line (34) has a mass-flow sensor (46b) between the compressor cooling line and the at least one ventilation inlet.
5. The fuel cell system (100) as claimed in claim 1, characterized in that the at least one ventilation inlet (52) is arranged in a lower third, in particular on a lower end (53), of the housing (50) and/or the at least one outflow outlet (54) is arranged in an upper third, in particular on an upper end (55), of the housing (50).
6. The fuel cell system (100) as claimed in claim 1, characterized in that a heat exchanger (60a) for controlling the temperature of the supply fluid is arranged in the fluidly communicating ventilation line (24), and/or a heat exchanger (60b) for controlling the temperature of the cooling fluid is arranged in the fluidly communicating compressor ventilation line (34).
7. The fuel cell system (100) as claimed in claim 1, characterized in that the fluidly communicating ventilation line (24) has therein a shut-off unit (62a) for interrupting the fluid communication between the first fluid source and the at least one ventilation inlet (52), and/or the compressor ventilation line (34) has therein a shut-off unit (62b) for interrupting the fluid communication between the second fluid source and the at least one ventilation inlet (52).
8. The fuel cell system (100) as claimed in claim 6, characterized in that the heat exchanger (60a) in the fluidly communicating ventilation line (24) and/or the shut-off unit (62a) in the fluidly communicating ventilation line (24) and/or the heat exchanger (60b) in the fluidly communicating compressor ventilation line (34) and/or the shut-off unit (62b) in the fluidly communicating compressor ventilation line (34) is/are controlled by means of a controller (66).
9. The fuel cell system (100) as claimed in claim 1, characterized in that the fuel cell system (100) comprises a fluidly communicating outflow line (56) between the at least one outflow outlet (54) and an outflow element for connecting the at least one outflow outlet (54) to the outflow element.
10. A method (200) for ventilating a housing of a fuel cell system (100) as claimed in claim 1, wherein the method (200) has the steps of providing (202) a supply fluid compressing (203) the supply fluid by means of the compressor (16) flow (204) of the supply fluid in the supply line (14) flow (206) of at least some of the supply fluid as ventilation fluid in the fluidly communicating ventilation line (24) inflow (208) of the ventilation fluid into the at least one ventilation inlet (52) of the housing (50) flow (210) of the ventilation fluid through the housing (50) and simultaneously mixing (211) the ventilation fluid with hydrogen to give an outflow fluid, and outflow (212) of the outflow fluid from the at least one outflow outlet (54) of the housing (50) and/or the method (200) comprises the steps of providing (222) a cooling fluid compressing (223) the cooling fluid flow (224) of the cooling fluid in the compressor cooling line (32) to cool the compressor (16) flow (226) of at least some of the cooling fluid as ventilation fluid in the fluidly communicating compressor ventilation line (34) inflow (228) of the ventilation fluid into the at least one ventilation inlet (52) of the housing (50) flow (230) of the ventilation fluid through the housing (50) and simultaneously mixing (231) the ventilation fluid with hydrogen to give an outflow fluid, and outflow (232) of the outflow fluid from the at least one outflow outlet (54) of the housing (50).
11. A motor vehicle (300) having a fuel cell system (100) as claimed in claim 1.
12. A fuel cell system (100) with a) at least one fuel cell (90), wherein each of the at least one fuel cell (90) has a cathode inlet (92), b) a housing (50), in which the at least one fuel cell (90) is arranged, wherein the housing (50) has at least one ventilation inlet (52) for inflow of at least one ventilation fluid and at least one outlet (54) for the outflow of at least one outflow fluid, c) a supply line (14) to the cathode inlet (92) for providing a supply fluid from a first fluid source to the cathode inlet (92), and d) a compressor (16) in the supply line (14) for compressing the supply fluid, characterized in that the fuel cell system (100) further comprises: e) a fluidly communicating ventilation line (24) connecting the supply line (14) to the at least one ventilation inlet (52), wherein the fluidly communicating ventilation line (24) is connected to the supply line (14) between the compressor (16) and the at least one cathode inlet (92)
13. The fuel cell system (100) as claimed in claim 12, characterized in that a heat exchanger (42) is arranged in the supply line (14) between the compressor (16) and the at least one cathode inlet (92), and the fluidly communicating ventilation line (24) is connected to the supply line (14), which is situated between the heat exchanger (42) and the at least one fuel cell (90).
14. The fuel cell system (100) as claimed in claim 12, characterized in that a humidifier (44) is arranged in the supply line (14) between the compressor (16) and the at least one cathode inlet (92), and the fluidly communicating ventilation line (24) is connected to the supply line (14), which is situated between the humidifier (44) and the at least one fuel cell (90).
15. The fuel cell system (100) as claimed in claim 12, characterized in that the fluidly communicating ventilation line (24) has a mass-flow sensor (46a) between the supply line (14) and the at least one ventilation inlet (52).
16. The fuel cell system (100) as claimed in claim 12, characterized in that a heat exchanger (60a) for controlling the temperature of the supply fluid is arranged in the fluidly communicating ventilation line (24).
17. The fuel cell system (100) as claimed in claim 12, characterized in that the fluidly communicating ventilation line (24) has therein a shut-off unit (62a) for interrupting the fluid communication between the first fluid source and the at least one ventilation inlet (52).
18. The fuel cell system (100) as claimed in claim 16, characterized in that the heat exchanger (60a) in the fluidly communicating ventilation line (24) and/or the shut-off unit (62a) in the fluidly communicating ventilation line (24) is/are controlled by means of a controller (66).
19. The fuel cell system (100) as claimed in claim 13, wherein the heat exchanger (42) is a charge-air cooler.
20. A fuel cell system (100) with a) at least one fuel cell (90), wherein each of the at least one fuel cell (90) has a cathode inlet (92), b) a housing (50), in which the at least one fuel cell (90) is arranged, wherein the housing (50) has at least one ventilation inlet (52) for inflow of at least one ventilation fluid and at least one outlet (54) for the outflow of at least one outflow fluid, c) a supply line (14) to the cathode inlet (92) for providing a supply fluid from a first fluid source to the cathode inlet (92), and d) a compressor (16) in the supply line (14) for compressing the supply fluid, characterized in that the fuel cell system (100) further comprises: f) a compressor cooling line (32) for cooling the compressor (16) and a fluidly communicating compressor ventilation line (34) between the compressor cooling line (32) and the at least one ventilation inlet (52) for connecting the compressor cooling line (32) to the at least one ventilation inlet (52).
21. The fuel cell system (100) as claimed in claim 20, characterized in that the fluidly communicating compressor ventilation line (34) has a mass-flow sensor (46b) between the compressor cooling line and the at least one ventilation inlet.
22. The fuel cell system (100) as claimed in claim 20, characterized in that a heat exchanger (60b) for controlling the temperature of the cooling fluid is arranged in the fluidly communicating compressor ventilation line (34).
23. The fuel cell system (100) as claimed in claim 20, characterized in that the compressor ventilation line (34) has therein a shut-off unit (62b) for interrupting the fluid communication between the second fluid source and the at least one ventilation inlet (52).
24. The fuel cell system (100) as claimed in claim 22, characterized in that the shut-off unit (62b) in the fluidly communicating compressor ventilation line (34) is/are controlled by means of a controller (66).
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] Further measures that improve the invention will become apparent from the following description of a number of exemplary embodiments of the invention, which are illustrated schematically in the figures. All the features and/or advantages which emerge from the claims, the description or the drawings, including design details and spatial arrangements and method steps, may be essential to the invention either per se or in various combinations. It should be noted here that the figures have only a descriptive character and are not intended to restrict the invention in any form.
[0045] The following figures are each schematic and
[0046] FIG. 1 shows a fuel cell system having a ventilation line,
[0047] FIG. 2 shows a fuel cell system having a compressor ventilation line,
[0048] FIG. 3 shows a fuel cell system having a ventilation line and a compressor ventilation line,
[0049] FIG. 4 shows a fuel cell system having a ventilation line and a heat exchanger,
[0050] FIG. 5 shows a fuel cell system having a ventilation line and a humidifier,
[0051] FIG. 6 shows a fuel cell system having a ventilation line, a heat exchanger and a humidifier,
[0052] FIG. 7 shows a fuel cell system having a ventilation line, a heat exchanger and a humidifier,
[0053] FIG. 8 shows a fuel cell system having a ventilation line, a compressor ventilation line and mass flow sensors,
[0054] FIG. 9 shows a fuel cell system having a ventilation line, a bypass line, a bypass valve and a mass flow sensor,
[0055] FIG. 10 shows a fuel cell system having a ventilation line, a compressor ventilation line and heat exchangers,
[0056] FIG. 11 shows a fuel cell system having a ventilation line, a compressor ventilation line and shut-off units,
[0057] FIG. 12 shows a fuel cell system having a ventilation line, a compressor ventilation line, heat exchangers, shut-off units and a controller,
[0058] FIG. 13 shows a fuel cell system having a ventilation line and an outflow line,
[0059] FIG. 14 shows a housing of a fuel cell system,
[0060] FIG. 15 shows a method for ventilating a housing of a fuel cell system,
[0061] FIG. 16 shows a method for ventilating a housing of a fuel cell system, and
[0062] FIG. 17 shows a motor vehicle having a fuel cell system according to the invention.
DETAILED DESCRIPTION
[0063] In the following figures, identical reference signs are used for the same technical features, even of different exemplary embodiments.
[0064] FIGS. 1 to 13 show a fuel cell system 100 according to the invention with a compressor 6 and a supply line 14 for supplying the at least one fuel cell 90 with a supply fluid, in particular air. The supply line 14, which is not arranged between the compressor 16 and the at least one fuel cell 100, can be connected to a first fluid source, in particular the ambient air. This first fluid source and a second fluid source are not illustrated in FIGS. 1 to 11 and are also not covered by the subject matter of the invention. The compressor 16 compresses the supply fluid. The supply line 14 between the compressor 16 and the at least one fuel cell 90 is connected to the at least one cathode inlet 92 of the at least one fuel cell 90 and carries the compressed supply fluid. The at least one fuel cell 90 is arranged in a housing 50. The housing 50 can be used to protect the fuel cell but can be used especially to protect living beings. For all fluid-carrying lines, electrical lines, etc., the housing 50 has openings. Furthermore, the housing 50 has at least one ventilation inlet 52 and at least one outflow outlet 54. Lines for ventilating the interior of the housing 50 with ventilation fluids can be connected to this at least one ventilation inlet 52. Advantageously, a ventilation fluid flows through the interior of the housing 50 and flows out again from the at least one outflow outlet 54. According to the invention, the at least one ventilation fluid is a pressurized fluid necessary for the operation of the fuel cell system. This necessary fluid can be a supply fluid compressed by the compressor 16 and/or a compressed cooling fluid, which is required for cooling the compressor 16. A flow of a ventilation fluid through a housing 50 takes place through fluidly communicating ventilation lines 24 and/or fluidly communicating compressor ventilation lines 34 according to the invention. By using the pressurized fluids necessary for the operation of the fuel cell system, ventilation of a housing 50 can take place in a simple and low-cost manner. Furthermore, a pressurized fluid has the advantage for ventilation of a housing that accidentally escaped hydrogen is carried away from a housing particularly quickly, efficiently and safely. By means of the ventilation, it is advantageously possible to avoid hydrogen collecting in a high concentration in the housing 50 and becoming a hazard. Furthermore, temperature control of the at least one fuel cell 90 in the housing 50 can be brought about by the throughflow of a ventilation fluid. This temperature control can also influence the power of the fuel cell system 100, it being particularly advantageous if the at least one fuel cell 90 is adjusted to its optimum operating point. Various possible embodiments illustrated in FIGS. 1 to 11 will be discussed in more detail in the following paragraphs.
[0065] FIG. 1 shows a fuel cell system 100 according to the invention, wherein a fluidly communicating ventilation line 24 connects the supply line 14 to the at least one ventilation inlet 52 of the housing 50. Through this connection, the pressurized supply fluid can flow via the fluidly communicating ventilation line 24 into the housing 50 for ventilation of the housing 50. It is advantageous that the pressurized supply fluid, which is simultaneously used to supply the cathode of the at least one fuel cell 90, is used for ventilation. A separate compressor or a fan for ventilating the housing 50 is thereby eliminated. In FIG. 1, the ventilation line 24 extends outside the housing 50 to the at least one ventilation inlet 52. In this case, the ventilation line 24 could also run completely or partially within the housing 50.
[0066] FIG. 2 shows a fuel cell system 100 according to the invention, wherein the compressor 16 is additionally cooled by means of a compressor cooling line 32. A compressor ventilation line 34 connects the one end of the compressor cooling line 32 to the at least one ventilation inlet 52. The other end of the compressor cooling line 32 can be connected to a second fluid source, in particular the ambient air. It is advantageous here that the fluid used for cooling the compressor 16 is also simultaneously used as ventilation fluid for ventilation of the housing 50. This means that ventilation of a housing 50 takes place in a particularly simple and low-cost manner. An additional compressor or a fan for ventilating the housing 50 can thereby be eliminated.
[0067] FIG. 3 shows a combination of FIG. 1 and FIG. 2. This fuel cell system 100 according to the invention has both a ventilation line 24 and a compressor 16 with a compressor cooling line 32 and a compressor ventilation line 34. This means that, on the one hand, the cooling fluid can flow by means of the compressor ventilation line 34 and, on the other hand, the supply fluid can flow by means of the ventilation line 24 into the housing 50 via the ventilation inlets 52. Together, they flow through the housing 50 as a ventilation fluid and emerge again at the ventilation outlet 54. It is advantageous here that the effective diameter of the ventilation line 24 can be kept small since some of the ventilation fluid is provided by the cooling fluid. A small diameter of the ventilation line 24 also has the advantage that the pressure of the supply fluid at the at least one cathode inlet 92 of the at least one fuel cell 90 substantially corresponds to the output pressure of the compressor 16. The power of the at least one fuel cell 90 can be kept high despite the additional ventilation line 24.
[0068] A fuel cell system 100 according to the invention, illustrated in FIG. 4, corresponds to FIG. 1, wherein, in addition, in FIG. 4, a heat exchanger 42, in particular a charge-air cooler (intercooler), is arranged in the supply line 14. The heat exchanger 42 controls the temperature of the supply fluid to a temperature suitable for the operation of the at least one fuel cell 90. At the same time, according to the invention, the temperature-controlled supply fluid can flow by means of the ventilation line 24 via the at least one ventilation inlet 52 into the housing 50 as temperature-controlled ventilation fluid, can flow through the housing 50 and can flow out of the outflow outlet 54. It is advantageous here that the temperature-controlled ventilation fluid can also flow around the at least one fuel cell 90 as it flows through the housing 50. Since heat may be generated during operation of the at least one fuel cell 90, explosive hydrogen, heat from the at least one fuel cell 90 and/or heated air surrounding the fuel cell can be removed via the outflow outlet 54 with the aid of the ventilation fluid flowing through. Heating of the at least one fuel cell 90 by a temperature-controlled ventilation fluid would likewise be possible. This could be necessary when using the fuel cell system 100 in a vehicle at cold temperatures, in particular when starting the vehicle.
[0069] The fuel cell system 100 according to the invention, shown in FIG. 5, corresponds to FIG. 1, wherein, in addition, in FIG. 5, a humidifier 44 is arranged in the supply line 14. The supply fluid humidified by the humidifier 44 on the one hand flows into at least one cathode inlet 92 of the at least one fuel cell 90 by means of the supply line 14 and on the other hand flows into the housing 52 as humidified ventilation fluid by means of the ventilation line 24 via the at least one ventilation inlet 52. By means of the humidified ventilation fluid, explosive hydrogen, heat from the at least one fuel cell 90 and/or heated air surrounding the fuel cell 90 can advantageously be removed. This can bring about an increase in the performance of the at least one fuel cell 90, but can also contribute to the safety of the fuel cell system 100. The water in the humidified ventilation fluid can additionally contribute to the cooling of the at least one fuel cell 90. Furthermore, the humidified ventilation fluid can perform a cleaning function. This means that dirt and dust in the interior of the housing 50 flows out of the outflow outlet 54 with the humidified ventilation fluid. It is also conceivable for dirt and dust to be as it were washed off and discharged to the outside via a dirt outlet (not illustrated) in the housing 50. The housing 50 of the fuel cell system 100, the at least one fuel cell 90 and other parts within the housing 50 can be designed in such a way that they are not damaged by the moisture of the humidified ventilation fluid. In particular, a humidifier 44 can humidify the supply fluid in such a way that an optimum operating point for the at least one fuel cell 90 is set.
[0070] FIG. 6 shows a fuel cell system 100 according to the invention as per FIG. 4, wherein, in addition, in the supply line 14, a humidifier 44 is connected downstream of a heat exchanger 42 and the ventilation line 24 is connected to the supply line 14, which is situated between the heat exchanger 42 and the humidifier 44. Consequently, as already described with reference to FIG. 4, a temperature-controlled ventilation fluid flows into the housing 52. For the purpose of the humidifier 44, on the other hand, a humidified and temperature-controlled supply fluid flows into the at least one cathode inlet. This results in at least the same advantages for this fuel cell system as those already explained in FIG. 4. A further advantage in this embodiment is that the temperature-controlled ventilation fluid flowing into the at least one ventilation inlet 52, in combination with the humidified and temperature-controlled supply fluid flowing into the at least cathode inlet 92 and thus into the at least one fuel cell 90, makes it possible to operate the fuel cell system 100, in particular the fuel cell 90, in a particularly favorable, efficient and safe manner.
[0071] FIG. 7 shows a fuel cell system 100 corresponding to FIG. 6, wherein the ventilation line 24 is connected to the supply line 14, which is situated between the humidifier 44 and the at least one cathode inlet 92. Thus, as already described in FIG. 6, a humidified and temperature-controlled supply fluid flows into the at least one cathode inlet 92 of the at least one fuel cell 90. This humidified and temperature-controlled supply fluid also flows simultaneously into the housing 50 by means of the ventilation line 24, via the at least one ventilation inlet 52. For the fuel cell system 100 in this embodiment, the advantages for the ventilation of the housing 50 with a temperature-controlled ventilation fluid are therefore combined, see description FIG. 4, and the advantages for the ventilation of the housing 50 with a humidified ventilation fluid are combined, see description FIG. 5.
[0072] FIG. 8 discloses a fuel cell system 100 according to the invention of the kind illustrated in FIG. 3, wherein, in addition, a mass flow sensor 46a is arranged in the ventilation line 24 and a mass flow sensor 46b is arranged in the compressor ventilation line 34. A mass flow sensor 46a, 46b has the advantage that the rate of flow of the supply fluid through a ventilation line 24 according to the invention and the rate of flow of the cooling fluid through a compressor ventilation line 34 can be detected and thus subjected to open-loop or closed-loop control. Advantageously, a flow rate of a ventilation fluid, i.e. of a supply fluid and/or of a cooling fluid, can be set to a minimum by open-loop or closed-loop control, while it is still possible, nevertheless, to achieve adequate ventilation of a housing 50. Furthermore, it is also possible to monitor by means of a mass flow sensor 46a, 46b whether the supply fluid is flowing into the housing 50 for ventilation and whether safe operation of the fuel cell system 100 is possible.
[0073] FIG. 9 discloses a fuel cell system 100 according to the invention of the kind illustrated in FIG. 1, wherein, in addition, a mass flow sensor 46a is arranged in the ventilation line 24. It is conceivable for one end of a fluidly communicating bypass line 48 of the fuel cell system 100 to be connected to the ventilation line 24, meaning the ventilation line 24 between mass-flow sensor 46a and the at least one ventilation inlet 52. This bypass line 48 can have a valve 49, in particular an electrically controllable valve. The other end of the fluidly communicating bypass line 48 can end, for example, in the open (surroundings) or in the exhaust of a motor vehicle which has a fuel cell system 100 according to the invention. Opening the valve 49 in the bypass line 48 enables the supply fluid to flow out of the bypass line. It is thereby possible to reduce the pressure of the supply fluid in the supply line 14 and the pressure in the ventilation line 24.
[0074] FIG. 10 illustrates a fuel cell system 100 according to the invention, wherein a heat exchanger 60a for controlling the temperature of the supply fluid is arranged in the ventilation line 24, and a heat exchanger 60b for controlling the temperature of the cooling fluid is arranged in the compressor ventilation line 34. It is thereby advantageously possible to control the temperature of the at least one fuel cell 90 by means of the temperature-controlled supply fluid and temperature-controlled cooling fluid flowing in the housing 50. It would also be conceivable for a common heat exchanger to be used to control the temperature of the supply fluid and of the cooling fluid. In this case, it is advantageous that the costs are reduced and less space is required for accommodating a heat exchanger, particularly in a vehicle. The heat exchanger 60a in the ventilation line 24 also has the advantage that the temperature of the supply fluid flowing into the housing 50 as ventilation fluid can differ from the temperature of the supply fluid flowing into the at least one cathode inlet 92 as a supply fluid. This means that, on the one hand, optimum supply of the at least one fuel cell 90 with the temperature-controlled supply fluid is possible and, on the other hand, optimum ventilation of the housing 50 with the temperature-controlled ventilation fluid is possible. It is thereby possible to obtain a particularly favorable operating point for the fuel cell system 100, in particular for the at least one fuel cell 90.
[0075] FIG. 11 shows a fuel cell system 100 according to the invention, wherein a shut-off unit 62a is arranged in the ventilation line 24 and a shut-off unit 62b is arranged in the compressor ventilation line 34. Shut-off unit 62a allows for an interruption in the fluid communication between the first fluid source (not shown) and the at least one ventilation inlet 52, and shut-off unit 62b allows for an interruption in the fluid communication between the second fluid source (not shown) and the at least one ventilation inlet 52. A shut-off unit 62a, 62b can be, for example, a cock or valve, in particular a valve subjected to closed-loop or open-loop control. The flow of the supply fluid and/or of the cooling fluid through the at least one ventilation inlet 52 can thereby advantageously be subjected to open-loop and/or closed-loop control. It is also conceivable for just one shut-off unit 62a to be arranged in the ventilation line 24. It is thereby possible, on the one hand, to achieve continuous ventilation of the housing 50 by means of the compressor ventilation line 34. On the other hand, if necessary, the ventilation of the housing 50 can be intensified if the shut-off unit 62a in the ventilation line 24 is at least partially “open” and, in addition, the supply fluid flows through the housing 50 as a ventilation fluid. There could be a need, for example, if large amounts of hydrogen escape in the housing 50 owing to a technical defect, and increased removal of hydrogen becomes necessary in order to improve the safety of the fuel cell system 100.
[0076] FIG. 12 illustrates a fuel cell system 100 according to the invention, wherein, as in FIG. 10, a heat exchanger 60a is arranged in the ventilation line 24 and a heat exchanger 60b is arranged in the compressor ventilation line 34 and, as in FIG. 11, a shut-off unit 62a is arranged in the ventilation line 24 and a heat exchanger 62b is arranged in the compressor ventilation line 34. In addition, FIG. 12 shows a controller 66 as part of the fuel cell system 100 according to the invention. The controller 66 can control the heat exchangers 60a, 60b and/or the shut-off units 62a, 62b in such a way that the temperature-controlled and/or throttled at least one ventilation fluid flowing into the housing 50 makes it possible to operate the fuel cell 90 in a particularly favorable, safe and advantageous manner. This can mean that the temperature and power of the fuel cell 90 can be controlled by a temperature-controlled and/or throttled ventilation fluid. The controller 66 can furthermore control the fuel cell system 100 in such a way that continuous ventilation of the housing 50 takes place via the compressor ventilation line 34, and the housing 50 is additionally ventilated via the ventilation line 24 only when required. The supply fluid can thereby be made fully available to the at least one cathode inlet 92. The controller 66 may further comprise a hydrogen concentration sensor (not shown) in the housing 52, wherein the controller 66 controls ventilation of the housing 50 as a function of the measured hydrogen concentration.
[0077] FIG. 13 shows a fuel cell system 100 according to the invention with an outflow line 56 between the at least one outflow outlet 54 and an outflow element (not shown). An outflow line 56 can be understood to mean, for example, a line, pipe or hose. This outflow line 56 can enable controlled and selective removal of an outflow fluid. It is particularly advantageous if the housing 50 is designed to be fluid-tight. Fluid-tight means that no chamber fluid randomly flows from the interior of the housing 50 to the exterior of the housing 50. The interior of the housing 50 is the space surrounded/enclosed by the housing 50. The exterior of the housing 50 is the space not surrounded/not enclosed by the housing 50. In particular, chamber fluid means an air mixture (e.g. air with hydrogen) in the housing 50 which surrounds the at least one fuel cell 90 and other parts, such as lines to the at least one cathode inlet 92 of the at least one fuel cell 90. In a fluid-tight housing 50, therefore, a chamber fluid, in particular a ventilation fluid, can flow out only specifically via the at least one outflow outlet 54. A fuel cell system 100 according to the invention with a fluid-tight housing 50 and an outflow line 56 can consequently make it possible for an outflow fluid with hydrogen to be directed to a non-hazardous location, in particular into the open. The outflow line 56 can also connect the at least one outflow outlet 54 to a container as an outflow element. This container can be used to collect the hydrogen of the outflow fluid. The outflow line 56 can also connect the at least one outflow outlet 54 to an exhaust of a vehicle as an outflow element.
[0078] FIG. 14 illustrates a housing 50 of a fuel cell system 100 according to the invention, only the housing 50 having three ventilation inlets 52 and three outflow outlets 54 being illustrated in FIG. 14 for the sake of clarity. The at least one fuel cell 90 (not illustrated) according to the invention can be arranged in the housing 50. The two dotted lines divide the housing 50 into three thirds, namely into a lower third, a middle third and an upper third. The three ventilation inlets 52 are located in the lower third, two ventilation inlets 52 being arranged on a lower end 53. The three outflow outlets 54 are located in the upper third, two outflow outlets 52 being arranged on an upper end 55. The lower third, in particular the lower end 53, is closer to the center of the earth than the upper third, in particular the upper end 55. The at least one fuel cell 90 is preferably arranged in the housing 50 in such a way that the accidentally escaping hydrogen can collect in the upper third of the housing 50 owing to its lower density relative to air. If hydrogen escapes in the lower third of a housing 50, there is a natural flow S of hydrogen from the lower third of the housing 50 in the direction of the upper third of the housing 50 since hydrogen is lighter than air. The removal of the hazardous hydrogen is particularly favorable by virtue of the arrangement of the three outflow outlets 54 in the upper third of the housing 50. In particular, the arrangement of the two outflow outlets 54 on the upper end 55 of the housing 50 assists a particularly advantageous natural removal of the hydrogen. If a fuel cell system according to the invention is installed in a vehicle, it is conceivable for a plurality of outflow outlets 54 to be arranged on the upper end 55, in particular on the edges and/or the center of the upper end 55, thus enabling the outflow fluid to flow out of the housing 50 in a particularly favorable manner via an outflow outlet 54, depending on the vehicle position. The arrangement of the three ventilation inlets 52 in the lower third of the housing can furthermore assist removal of accidentally escaping hydrogen. In particular, if hydrogen escapes in the lower third of the housing 50, the ventilation fluid can mix with the hydrogen in an improved way and flow out of an outflow outlet 54. It may be particularly advantageous if at least one ventilation inlet 52 is arranged in the lower third and at least one outflow outlet 54 is arranged in the upper third. More specifically, it is possible as a result for a ventilation fluid to flow around particularly long distances in the housing 50, many points of the housing 50 and further parts located in the housing 50, such as, for example, lines, from the at least one ventilation inlet 52 to the at least one ventilation outlet 54. Consequently, most points in the housing 50 at which hydrogen has collected and/or most points of the at least one fuel cell 90 at which hydrogen accidentally escapes are covered by the flow of the ventilation fluid. With the aid of the ventilation fluid flowing through, it is also possible for the heat generated during operation of the at least one fuel cell 90 to be removed from the at least one fuel cell 90 and/or for heated air surrounding the at least one fuel cell to be removed via the at least one outflow outlet 54. Thus, ventilation of a housing takes place in a low-cost and simple manner, and furthermore the safety of the fuel cell system is improved. However, arrangement of ventilation inlets 52 and outflow outlets 54 in the central region of the housing 50 is not excluded. Depending on the arrangement of a housing 50 of a fuel cell system 100, arrangement of the ventilation inlets 52 and outflow outlets 54 can be adapted to, for example, a body of a vehicle.
[0079] FIG. 15 illustrates a method 200 according to the invention, wherein the supply fluid is provided 202 for the ventilation of the housing 50 by a supply fluid in a first step. This supply fluid can be provided by a first fluid source, which is, in particular, the ambient air, and can be compressed 203 by a compressor 16. Starting from the first fluid source, the supply fluid flows 204 in the supply line 14 in the direction of the fuel cell 90. A fluidly communicating ventilation line 24 between the supply line 14 and at least one ventilation inlet 52 of a housing 50 makes it possible for at least some of the supply fluid to flow 206 as ventilation fluid in the fluidly communicating ventilation line 24. This ventilation fluid flows 208 into the at least one ventilation inlet 52 of the housing 50, flows 210 through the housing 50 and mixes 211 with hydrogen to give an outflow fluid and flows 212 out as outflow fluid from the at least one outflow outlet 54 of the housing 50.
[0080] FIG. 16 illustrates a method 200 according to the invention, wherein the cooling fluid is provided 222 for the ventilation of the housing 50 in a first step. This cooling fluid can be provided by a second fluid source, which is, in particular, the ambient air, and can be compressed 223 by a cooling fluid compressor (not illustrated). The second fluid source and the first fluid source may be the same fluid source. Starting from the second fluid source, the cooling fluid flows 224 in the compressor cooling line 32 through the compressor 16 and cools the compressor 16. A fluidly communicating compressor ventilation line 34 between the compressor cooling line 32 and at least one ventilation inlet 52 of a housing 50 makes it possible for at least some of the cooling fluid to flow 226 as ventilation fluid in the fluidly communicating compressor ventilation line 34. This ventilation fluid flows 228 into the at least one ventilation inlet 52 of the housing 50, flows 230 through the housing 50 and mixes 231 with hydrogen to give an outflow fluid and flows 232 out as outflow fluid from the at least one outflow outlet 54 of the housing 50.
[0081] The ventilation of the housing 50 by the supply fluid and/or the cooling fluid preferably takes place continuously. Furthermore, ventilation of the housing 50 under closed-loop and/or open loop control by a controller 66 is conceivable.
[0082] FIG. 17 illustrates a motor vehicle 300 having a fuel cell system 100 according to the invention.
