DE19743075A1 - Fuel cell arrangement - Google Patents

Abstract

A fuel cell arrangement has a number of fuel cells located in a stack(10 and surrounded by a protective housing (2), with an anode inlet (5) for the supply of fuel gas to the anodes, an anode outlet for burnt fuel gas, a cathode inlet for the supply of cathode gas to the cathodes, a cathode outlet for used cathode gas and a device by which cathode gas inside the protective housing is displaced into circulation in a circuit from the cathode outlet to the cathode inlet. The device to circulate the cathode gas is formed by an ejector arrangement provided in the cathode gas stream. The driven gas stream of the ejector arrangement is the cathode gas stream and the driving gas stream in the arrangement is a gas to be added to the cathode gas stream.

Description

The invention relates to a fuel cell arrangement according to the preamble of the claim 1.

Specifically, it is a fuel cell arrangement with a number of Fuel cells arranged in a fuel cell stack and by one Protective housing are surrounded, and the anode input for supplying fuel gas to the anodes of the fuel cells, an anode outlet for the discharge of the burned Fuel gas from the anodes to a cathode inlet for supplying cathode gas the cathodes of the fuel cells and a cathode outlet for removing the has spent cathode gas from the cathodes. Furthermore, the Fuel cell arrangement via a device through which the cathode gas inside of the protective housing in a circuit from the cathode outlet to the cathode inlet in Circulation is offset.

Such a fuel cell arrangement with an internal cathode gas circuit, which is also known as so-called "hot module" is known from DE 44 25 186 C1 of the applicant described, the details of which are referred to here. In this known Fuel cell assembly is the used cathode gas from the cathode gas outlet in a freely circulating circuit flow within the protective housing in circulation  added and air and anode exhaust gas added. The cathode gas flow passes through a catalytic burner in which the combustible residual components of the burned Anode exhaust gas can be converted into thermal energy. The cathode gas cycle is returned to the cathode input of the fuel cell assembly, whereby the Circuit via the cathodes is closed. With the known The cathode gas circuit is fuel cell arrangement by means of one or more Hot gas blower operated within the protective housing of the fuel cell assembly are arranged.

A disadvantage of the known fuel cell arrangement is that the Hot gas blowers arranged within the protective housing because of the relatively small Density of the circulating hot gas (approx. 540 to 550 ° C) a poor efficiency exhibit. In addition, due to these high operating temperatures, they are considerable Requirements for the design and material of the hot gas blower to meet a to achieve sufficient lifespan. Nevertheless, the probability of failure is one such hot gas blower not insignificant.

The object of the invention is to provide a fuel cell arrangement of the required type with internal cathode gas circuit to create which is more reliable having.

This object is achieved by a fuel cell arrangement with the in claim 1 specified features solved.

Advantageous developments of the fuel cell arrangement according to the invention are in the Subclaims marked.

According to the invention, a fuel cell arrangement with a number of Fuel cells created, arranged in a fuel cell stack and by one Protective housing are surrounded. The fuel cell arrangement has one  Anode input for supplying fuel gas to the anodes of the fuel cells, one Anode outlet for removing the burned fuel gas from the anodes, one Cathode input for supplying cathode gas to the cathodes of the fuel cells and a cathode outlet for removing the used cathode gas from the Cathodes. Furthermore, a device is provided through which the cathode gas in Inside the protective housing in a circuit from the cathode outlet to Cathode input is circulated. According to the invention, this device is for Circulating the cathode gas through one provided in the cathode gas flow Ejector arrangement formed.

An advantage of the fuel cell arrangement according to the invention is that the device no moving parts inside the protective housing to circulate the cathode gas which are exposed to the high temperatures prevailing there.

The driven gas flow of the ejector arrangement is advantageously that Cathode gas flow.

The driving gas stream of the ejector arrangement is preferably one of the cathode gas stream gas to be mixed.

The driving gas stream is advantageously fresh air to be mixed with the cathode gas.

A blower can be provided for supplying the fresh air to the ejector arrangement.

This blower is advantageously arranged outside the protective housing. this has the advantage that the blower can be operated at ambient temperature and thus has a much better efficiency than one inside the protective housing arranged hot gas blower.  

A heat exchanger is advantageously arranged within the protective housing, which the gas stream circulating in the protective housing for temperature regulation of the Fuel cell assembly extracts heat.

Such a heat exchanger can be a gas / gas heat exchanger.

Air can be applied to the heat exchanger as a cooling medium.

According to advantageous embodiments of the invention, a is inside the protective housing arranged catalytic burner, which circulates in the protective housing Combustible residual components of the fuel gas contained in the gas stream burn.

In advantageous embodiments of the invention it is provided that the Anode outlet of the fuel cells opens into the interior of the protective housing to the Mix anode exhaust gas into the circulating cathode gas stream.

According to a first particular embodiment of the invention, the anodes are the Fuel cells can be flowed through in cross-flow to their cathodes, and they are means provided to the fuel gas stream leaving the anode outlet together with the the cathode gas stream leaving the cathode outlet on the inlet side of the Feed ejector assembly.

The heat exchanger is advantageously between the cathode outlet and the The inlet side of the ejector arrangement is arranged in the cathode gas flow.

In advantageous embodiments of the invention, the catalytic burner is Ejector arranged downstream in the circulating cathode gas stream. However, he can also be arranged in front of the ejector.  

According to a second particular embodiment of the invention, the anodes are The cathodes can flow through fuel cells in direct current, and they are means provided to the fuel gas stream leaving the anode outlet together with the the cathode gas stream leaving the cathode outlet on the inlet side of the Feed ejector.

Here are advantageously the means to the fuel gas flow with the Summarize cathode gas flow through the anode outlet and Cathode output of the fuel cell arrangement covering inlet hood of the Ejector arrangement formed.

According to a third particular embodiment of the invention, it is provided that the anodes of the fuel cells can be flowed through in countercurrent to their cathodes, wherein the fuel gas leaving the anode outlet of the fuel cells with that in the Cathode input of the fuel cell entering gas stream is mixed, and the Ejector arrangement in the flow of the circulating cathode gas between the cathode outlet and cathode input of the fuel cells is arranged.

In this embodiment, the catalytic burner is advantageously between the anode output and the cathode input of the fuel cells.

Advantageously, the cathode input of the fuel cells is against the Anode output of the fuel cells are arranged offset, and the catalytic burner is in the form of a flat arrangement between the anode outlet and the cathode inlet intended.

In all embodiments of the invention it can be advantageous if the ejector arrangement contains several individual ejectors.

Exemplary embodiments of the invention are explained below with reference to the drawing. Show it:

FIG. 1a) and b) are used in the front view and the side view of sections of a fuel assembly of known type in which hot gas blower as means for circulating cathode gas stream;

Figures 2a) and b) in the front view and the side view of sections through a fuel cell assembly according to a first embodiment of the invention, wherein the device is formed for circulating cathode gas stream through an ejector.

3 shows in side view a section through a fuel cell assembly according to a second embodiment of the invention, wherein the device is formed for circulating cathode gas stream through an ejector.

4 shows in side view a section through a fuel cell assembly according to a third embodiment of the invention, wherein the device is formed for circulating cathode gas stream through an ejector. and

FIG. 5 seen in an enlarged sectional view along the line AA of FIG. 4, a detail which shows the arrangement of the cathodes and anodes at the lower end of the fuel cell arrangement.

Fig. 1a) and 1b) show in front view and in side sectional views of a fuel cell assembly with internal cathode gas loop as it is known from DE 44 25 186 C1. In a protective housing 2 , which is gas-tight and thermally insulating, there is a fuel cell arrangement, the main component of which consists of a number of fuel cells arranged in a fuel cell stack 1 . The fuel cells contain anodes, through which a fuel gas B can flow vertically from bottom to top, and cathodes, which can be flowed through horizontally from right to left in cross-flow to the anodes in the representation of FIG. 1a). The anodes are thus flowed through vertically from bottom to top from an anode input 5 to an anode output 6 and the cathodes are flowed horizontally from right to left from a cathode input 7 to a cathode output 8 . The fuel gas B is supplied to the anode inlet 5 via a Brenngashutze 5 a, which separates the gas-tight anode inlet towards the interior of the protective housing. 2

At the top of the fuel cell stack 1 there is a diffuser 12 which serves to even out the flow of the anode exhaust gas leaving the anode outlet 6 . Anode gas mixer 9 is provided above the diffuser 12 , in which the anode exhaust gas is mixed with the cathode gas stream circulating inside the protective housing 2 and fresh air supplied at L is added to this mixture. Downstream of the anode gas mixer 9, a catalytic burner 10 is provided, in which combustible residual components of the fuel gas still present in the gas mixture are catalytically burned and converted into thermal energy.

The cathode gas flow passing through the cathodes of the fuel cells from right to left and mixed with the anode exhaust gas in the anode gas mixer 9 is set in circulation by means of a blower 4 which is set in rotation by a blower drive 4 a provided outside the protective housing 2 . The cathode gas stream passes through a the fuel cell stack at the cathode input 7 upstream heater and diffuser 11 and the fuel cell stack at the cathode outlet 8 downstream heat exchanger to the fuel gas preheating heat exchanger 3, and a sixteenth The preheater and diffuser 11 serve to equalize the cathode gas flow before entering the cathode inlet 7 and to preheat it to operating temperature when the fuel cell arrangement is started up. In the heat exchanger 3 for preheating fuel gas, part of the thermal energy of the cathode gas stream leaving the cathodes is decoupled and used for preheating the fuel gas B to be fed to the anode input 5 . The heat exchanger 16 serves to decouple part of the heat from the circulating cathode gas stream and thus to regulate the heat balance of the fuel cell arrangement. In other words, the temperature inside the closed system surrounded by the protective housing 2 is regulated by the heat exchanger 16 .

Excess cathode gas is discharged from the protective housing 2 as the exhaust gas of the fuel cell arrangement at the point denoted by A. The exhaust gas quantity A is the chemical equivalent of the flows of fuel gas B and fresh air L supplied to the fuel cell arrangement.

FIG. 2a) and b) shows the front view and the side view of sections through a first embodiment of a fuel cell assembly according to the invention. A number of fuel cells are arranged in a fuel cell stack 1 . The fuel cell stack 1 is surrounded by a protective housing 2 , which encloses the fuel cell arrangement in a gas-tight manner and is thermally insulated from the surroundings. Similar to the known fuel cell arrangement shown in FIG. 1, the anodes of the fuel cells are flowed through vertically from bottom to top with fuel gas B, whereas the cathodes in crossflow flow horizontally, namely from right to left in the illustration in FIG. 2a) will. The fuel gas B is supplied to the bottom of the fuel cell stack via a Brenngashutze 5 a distributed through the anode inlet 5 of the fuel cell. At the top of the fuel cell stack, the flow of the burned fuel gas leaves the anode outlet 6 of the fuel cells and, after passing through a diffuser 12 , which serves to equalize the anode exhaust gas flow, enters the cathode gas flow circulating inside the protective housing 2 .

The cathode gas flow circulating inside the protective housing 2 is driven by an ejector 24 . An ejector is basically a device in which the energy content of a flowing driving medium is used to suck in another, driven medium, to mix it with the driving medium and to blow it out. Well-known examples of this are the water jet pump, in which the driving water jet is used to create a vacuum, or the compressed air-driven paint spray gun, in which a driving air stream sucks in the paint and at the same time sprays it evenly through a nozzle.

In the ejector 24 , fresh air labeled L is supplied as the driving medium from the outside and is used to apply the energy for driving the cathode gas circulating inside the protective housing 2 . The cathode gas is combined on a collecting hood 22 with the anode exhaust gas leaving the diffuser 12 and mixed and fed to the inlet side of the ejector 24 . In the ejector 24 , the gas mixture of anode exhaust gas and cathode gas is further mixed with the fresh air L supplied. A catalytic burner 20 is arranged downstream of the outlet side of the ejector 24 and serves to catalytically burn combustible residual components of the anode exhaust gas still present in the circulating gas stream and convert them into thermal energy.

A preheater and diffuser 11 is arranged upstream of the cathode input 7 of the fuel cell stack 1 , which serves to even out the circulating cathode gas flow and to supply the inputs of the cathodes of the fuel cells uniformly and to bring the cathode gas to the required temperature when the fuel cell arrangement is started up. A heat exchanger for preheating fuel gas 3 is connected downstream of the cathode outlet 8 of the fuel cell arrangement. This serves to couple out heat from the circulating cathode gas flow for preheating the fuel gas B before it is fed to the anode input 5 . Further downstream, downstream of the heat exchanger 3 , is a heat exchanger 26 , through which heat is coupled out from the cathode gas stream circulating within the protective housing 2 in order to regulate the heat balance and thus the temperature of the fuel cell arrangement. In the exemplary embodiment described, the heat exchanger 26 is a gas / gas heat exchanger in which air is used as the cooling medium. Excess cathode gas is removed from the protective housing 2 as exhaust gas A. The exhaust gas A is the chemical equivalent to the flows of fresh air L and fuel gas B supplied to the fuel cell arrangement. The operating point of the fuel cell arrangement is established as an equilibrium state by the amount of heat coupled out at the heat exchanger 26 and the exhaust gas A discharged.

As can be seen from FIG. 2 b), several, namely four ejectors 24 are provided, which together form an ejector arrangement for circulating the cathode gas within the protective housing 2 .

Fig. 3 shows a cross-sectional view through a second embodiment of the fuel cell assembly according to the invention. A fuel cell stack 1 is in turn formed by a number of fuel cells. In contrast to the first exemplary embodiment of the invention described with reference to FIG. 2, the respective electrodes, namely the fuel gas and the cathode gas, flow through the anodes and cathodes of the fuel cells in direct current, namely in the illustration in FIG. 3, from left to right. For this purpose, the fuel gas B is distributed to the anodes of the individual fuel cells via an internal fuel gas distributor (so-called "internal manifold") in the interior of the fuel cell stack, whereas the cathode gas is distributed from the outside at a cathode inlet 7 to the inlet sides of the cathodes of the individual fuel cells. The burned fuel gas leaves the anodes as anode exhaust gas at the anode outlet 6 and the used cathode gas leaves as the cathode exhaust gas the cathodes at the cathode outlet 8 , both on the right side of the fuel cell stack 1 in the illustration in FIG. 3. On the right side of the fuel cell stack 1 is an ejector 34 arranged, which is connected via an inlet hood 39 to the fuel cell stack 1 . The flows of anode exhaust gas and cathode exhaust gas leaving the anode outlet 6 and the cathode outlet 8 are combined in the inlet hood 39 and fed to the ejector 34 as a driven medium. The driving medium of the ejector 34 is fresh air L, which is fed to the ejector 34 via a fresh air nozzle 35 . The fresh air L drives the cathode gas with the admixed anode exhaust gas and places it in a cathode gas stream circulating inside the protective housing 2 .

The output side of the ejector 34 is followed by a catalytic burner 30 , in which combustible residual components of the anode exhaust gas present in the circulating cathode gas stream are catalytically burned and converted into thermal energy. In the path of the cathode gas flow from the outlet side of the ejector 34 via the catalytic burner 30 back to the cathode input side 7 located on the left side of the fuel cell stack 1, there is a heat exchanger 36 in which thermal energy is coupled out of the circulating cathode gas in order to maintain the heat balance and To regulate the temperature of the fuel cell arrangement. In the exemplary embodiment shown, the heat exchanger 36 is a gas / gas heat exchanger, to which fresh air is supplied as a cooling medium at a cooling air inlet 37 and is discharged at a cooling air outlet 38 . Excess cathode gas is removed as the exhaust gas A from the inside of the protective housing 2 . The exhaust gas A represents the chemical equivalent to the supplied gas streams of fresh air L and fuel gas B. Due to the heat coupled out via the heat exchanger 36 and the exhaust gas A removed, the operating point of the fuel cell arrangement is established in the equilibrium state.

Fig. 4 shows in cross-sectional view of a third embodiment of the fuel cell assembly according to the invention. In a protective housing 2 there is a fuel cell stack 1 , which is formed from a number of fuel cells, each of which contains an anode and a cathode. The anode input 5 of the fuel cells is located on the top of the fuel cell stack 1 . There, an internal gas distributor (so-called "internal manifold") is provided, via which the fuel gas B is distributed inside the fuel cell stack to the input sides of the anodes. The fuel gas B thus flows through the anodes from top to bottom. In contrast, the cathodes of the fuel cells are traversed from bottom to top in counterflow to the anodes. A cathode gas distributor 7 a is provided on the cathode input side 7 of the fuel cells. The output sides of the anodes forming the anode outlet 6 open into the interior of the cathode gas distributor 7 a. However, the output sides of the anodes at 6 are offset in height from the input sides of the cathodes at 7, in other words, the anodes each protrude downward from the fuel cell stack 1 with respect to the cathodes, as shown in the detailed view of FIG enlarged form is shown. A catalytic burner 40 in the form of a two-dimensional arrangement, for example, is provided on the surface regions resulting therefrom between anode outlet 6 and cathode inlet 7 . B. provided in the form of a coating. This catalytic burner 40 is used to catalytically burn remaining combustible constituents contained in the anode exhaust gas and to convert them into thermal energy. The burned anode exhaust gas is mixed inside the cathode gas distributor 7 a with the cathode gas and fed to the cathode inlet 7 together with this. After leaving the cathode outlet 8 at the top of the fuel cell stack, the cathode gas enters the interior of the protective housing 2 . An ejector 44 is arranged there, which serves to circulate the cathode gas. The ejector 44 is driven by fresh air L, which is supplied as the driving medium at 45 . A control valve 47 serves to regulate the gas throughput through the ejector 44 . In the interior of the protective housing 2 , a heat exchanger 46 is also provided, with which thermal energy is coupled out of the cathode gas flow in order to regulate the heat balance and the temperature of the fuel cell arrangement. Furthermore, cathode gas is removed from the cathode gas stream as exhaust gas A. The exhaust gas A is the chemical equivalent to the supplied gas streams of fuel gas B and fresh air L. Thus, the operating point of the fuel cell arrangement is set in the equilibrium state by the heat exchanger 46 and the exhaust gas A removed.

In the normal operating state of the fuel cell arrangement according to the invention, a temperature of 540 ° C. and a density of 0.40 kg / m ³ is established for the circulating cathode gas after mixing with the anode exhaust gas. The fresh air L is supplied, for example, at a temperature of 30 ° C. and a density of approximately 1.14 kg / m ³ . The mixing ratio in the ejector of fresh air as the driving medium and circulating cathode gas as the driven medium can be 2: 3, for example.

The outlet pressure from the ejector can be around 85 mbar at an inlet pressure the mixture of circulating cathode gas and anode exhaust gas of about 50 mbar. At the high density difference between fresh air L and driven mixed gas at the specified temperatures is only a slight excess pressure the fresh air compared to the outlet pressure of about 85 mbar necessary to exert the necessary suction on the mixed gas.

The overpressure of the fresh air L can be easily by a fan Ambient temperature or possibly achieved by a side channel compressor will.

The fan for conveying the fresh air L, which is not shown in detail in FIGS. 2 to 4, which is fed to the ejectors, works under ambient conditions and therefore has a high efficiency and is only slightly susceptible to malfunction.

Reference list

1

Fuel cell stack

2nd

Protective housing

3rd

Heat exchanger

4th

fan

4th

a Fan drive

5

Anode input

5

a fuel gas scoop

6

Anode output

7

Cathode entrance

7

a Cathode gas distributor

8th

Cathode output

9

Anode gas mixer

10th

Catalytic burner

11

Preheater and diffuser

12th

Diffuser

16

;

26

;

36

Heat exchanger

20th

;

30th

;

40

Catalytic burner

22

Collecting hood

24th

;

34

;

44

Ejector

25th

;

35

;

45

Air intake

37

Cooling air inlet

38

Cooling air outlet

39

Inlet scoop

47

Control valve

Claims (21)

1. Fuel cell arrangement with a number of fuel cells, which are arranged in a fuel cell stack ( 1 ) and surrounded by a protective housing ( 2 ), with an anode input ( 5 ) for supplying fuel gas to the anodes of the fuel cells, an anode outlet ( 6 ) for removal the burned fuel gas from the anodes, a cathode inlet ( 7 ) for supplying cathode gas to the cathodes of the fuel cells and a cathode outlet ( 8 ) for discharging the used cathode gas from the cathodes, and with a device through which the cathode gas inside the protective housing ( 2 ) is circulated from the cathode outlet ( 8 ) to the cathode inlet ( 7 ), characterized in that the device for circulating the cathode gas is formed by an ejector arrangement ( 24 ; 34 ; 44 ) provided in the cathode gas flow. 2. Fuel cell arrangement according to claim 1, characterized in that the driven gas flow of the ejector arrangement ( 24 ; 34 ; 44 ) is the cathode gas flow. 3. Fuel cell arrangement according to claim 2, characterized in that the driving gas flow of the ejector arrangement ( 24 ; 34 ; 44 ) is a gas to be admixed to the cathode gas flow. 4. Fuel cell arrangement according to claim 3, characterized in that the driving Gas stream is fresh air to be mixed with the cathode gas. 5. Fuel cell arrangement according to claim 4, characterized in that a fan for supplying fresh air to the ejector arrangement ( 24 ; 34 ; 44 ) is provided. 6. Fuel cell arrangement according to claim 5, characterized in that the fan is arranged outside the protective housing ( 2 ). 7. Fuel cell arrangement according to one of claims 1 to 6, characterized in that within the protective housing ( 2 ), a heat exchanger ( 26 ; 36 ; 46 ) is arranged which the gas flow circulating in the protective housing ( 2 ) for temperature control of the fuel cell arrangement ( 1 ) heat deprives. 8. Fuel cell arrangement according to claim 7, characterized in that the heat exchanger ( 26 ; 36 ; 46 ) is a gas / gas heat exchanger. 9. Fuel cell arrangement according to claim 8, characterized in that the heat exchanger ( 26 ; 36 ; 46 ) is acted upon as a cooling medium with air. 10. Fuel cell arrangement according to one of claims 1 to 9, characterized in that a catalytic burner ( 20 ; 30 ; 40 ) is arranged within the protective housing ( 2 ), which burns contained in the protective housing ( 2 ) circulating gas stream combustible residual components of the fuel gas . 11. Fuel cell arrangement according to one of claims 1 to 10, characterized in that the anode outlet ( 6 ) opens into the interior of the protective housing ( 2 ) to mix the anode exhaust gas in the circulating cathode gas stream. 12. Fuel cell arrangement according to claim 11, characterized in that the anodes of the fuel cells can be traversed in cross flow to their cathodes, and that means ( 22 ) are provided to the fuel gas stream leaving the anode outlet ( 6 ) together with that leaving the cathode outlet ( 8 ) Supply cathode gas flow to the inlet side of the ejector assembly ( 24 ). 13. Fuel cell arrangement according to one of claims 7 to 12, characterized in that the heat exchanger ( 26 ; 36 ; 46 ) between the cathode outlet ( 8 ) and the inlet side of the ejector arrangement ( 24 ; 34 ; 44 ) is arranged connected in the cathode gas flow. 14. Fuel cell arrangement according to one of claims 10 to 13, characterized in that the catalytic burner ( 20 ; 30 ; 40 ) the ejector ( 24 ; 34 ; 44 ) is arranged downstream in the circulating cathode gas stream. 15. Fuel cell arrangement according to claim 11, characterized in that the anodes of the fuel cells can be flowed through in cocurrent with their cathodes, and that means are provided to the fuel gas stream leaving the anode outlet ( 6 ) together with the cathode gas stream leaving the cathode outlet ( 8 ) on the inlet side to feed the ejector device ( 34 ). 16. Fuel cell arrangement according to claim 15, characterized in that the means for combining the fuel gas flow with the cathode gas flow through an anode outlet ( 6 ) and the cathode outlet ( 8 ) of the fuel cell assembly ( 1 ) covering inlet scoop ( 35 ) of the ejector assembly ( 34 ) is formed. 17. A fuel cell arrangement according to claim 11, characterized in that the anodes of the fuel cells can be flowed through in countercurrent to their cathodes, the fuel gas leaving the anode outlet ( 6 ) of the fuel cells being mixed with the cathode gas entering the cathode inlet ( 7 ) of the fuel cells, and that the ejector arrangement ( 44 ) is arranged in the flow of the circulating cathode gas between the cathode outlet ( 8 ) and the cathode inlet ( 7 ) of the fuel cells. 18. Fuel cell arrangement according to claim 17, characterized in that the catalytic burner ( 40 ) is provided between the anode outlet ( 6 ) and the cathode inlet ( 7 ) of the fuel cells. 19. A fuel cell assembly according to claim 18, characterized in that the cathode inlet (7) of the fuel cell is arranged offset of the fuel cell to the anode outlet (6), and that the catalytic burner (40) in the form of a flat arrangement between the anode output (6) and cathode input ( 7 ) is provided. 20. Fuel cell arrangement according to one of claims 1 to 19, characterized in that the ejector arrangement ( 24 ; 34 ; 44 ) contains a plurality of individual ejectors. 21. Fuel cell arrangement according to one of claims 1 to 20, characterized in that the ejector arrangement ( 24 ; 34 ; 44 ) is formed with slot-shaped nozzles.