DE202013011963U1 - The fuel cell system - Google Patents

Abstract

A fuel cell system (100), in particular for producing low-oxygen air, comprising two or more fuel cell devices (102, 104, 128), each fuel cell device (102, 104, 128) comprising: - an oxidizer supply (106) for supplying an oxidant stream to one Cathode side (103) of the fuel cell device (102, 104, 128); A cathode exhaust gas guide (108) for discharging cathode exhaust gas from the cathode side (103) of the fuel cell device (102, 104, 128), wherein two or more fuel cell devices (102, 104, 128) are coupled or coupled to one another such that by means of a cathode exhaust gas guide ( 108) of a first fuel cell device (102), the cathode exhaust gas generated in this first fuel cell device (102) via the Oxidatorzuführung (106) a second fuel cell device (104) can be supplied as the oxidant stream of this second fuel cell device (104).

Description

The present invention relates to a fuel cell system, in particular for the production of oxygen-poor air.

Fuel cell systems are known from the prior art, for example from the EP 0 596 366 A1 , known.

The present invention has for its object to provide a fuel cell system by means of which air can be produced with low oxygen content.

• – eine Oxidatorzuführung zur Zuführung eines Oxidatorstroms zu einer Kathodenseite der Brennstoffzellenvorrichtung;
• – eine Kathodenabgasführung zur Abführung von Kathodenabgas von der Kathodenseite der Brennstoffzellenvorrichtung,

wobei zwei oder mehr Brennstoffzellenvorrichtungen derart miteinander gekoppelt oder koppelbar sind, dass mittels einer Kathodenabgasführung einer ersten Brennstoffzellenvorrichtung das in dieser ersten Brennstoffzellenvorrichtung erzeugte Kathodenabgas über die Oxidatorzuführung einer zweiten Brennstoffzellenvorrichtung als Oxidatorstrom dieser zweiten Brennstoffzellenvorrichtung zuführbar ist.This object is achieved according to the invention in that the fuel cell system comprises two or more fuel cell devices, each fuel cell device comprising:

• An oxidizer supply for supplying an oxidant flow to a cathode side of the fuel cell device;
• A cathode exhaust gas passage for discharging cathode exhaust gas from the cathode side of the fuel cell device,

wherein two or more fuel cell devices are coupled or coupled with each other such that by means of a cathode exhaust gas guide of a first fuel cell device, the cathode exhaust gas generated in said first fuel cell device can be supplied via the oxidator supply to a second fuel cell device as the oxidant flow of said second fuel cell device.

By coupling or coupling two or more fuel cell devices together to supply cathode exhaust gas to the one fuel cell device as the oxidant flow of the another fuel cell device, air of very low oxygen content can be generated by the fuel cell system.

The cathode exhaust gas generated in the first fuel cell device is preferably partially or completely supplied as an oxidant stream of the second fuel cell device.

• – eine Brennstoffzuführung zur Zuführung eines Brennstoffstroms zu einer Anodenseite der Brennstoffzellenvorrichtung;
• – eine Anodenabgasführung zur Abführung von Anodenabgas von der Anodenseite der Brennstoffzellenvorrichtung.

It may be provided that each fuel cell device further comprises:

• A fuel supply for supplying a fuel flow to an anode side of the fuel cell device;
• An anode exhaust gas guide for discharging anode exhaust gas from the anode side of the fuel cell device.

In each fuel cell device, fuel and oxidizer are preferably converted to generate electrical energy.

In one embodiment of the invention, it is provided that the oxidator flow of the first fuel cell device is air, in particular ambient air, for example fresh air.

Ambient air, such as fresh air, preferably has an oxygen content of from about 20% to about 21% by volume.

It may be favorable if a valve device is arranged between the cathode exhaust gas guide of the first fuel cell device and the oxidizer feed of the second fuel cell device.

By means of the valve device, a gas, for example additional air, in particular ambient air, can be fed to the oxidizer flow for the second fuel cell device, in particular in addition to the cathode exhaust gas from the first fuel cell device.

Furthermore, it can be provided that a valve device is arranged between the cathode exhaust gas guide of the first fuel cell device and the oxidizer feed of the second fuel cell device, by means of which at least part of the cathode exhaust gas of the first fuel cell device can be discharged, in particular not supplied to the second fuel cell device.

The part of the cathode exhaust gas of the first fuel cell device, which can be discharged by means of the valve device, can be fed, for example, to a further, in particular a third, fuel cell device.

In one embodiment of the invention, it is provided that the fuel cell system comprises at least a third fuel cell device, which cathode exhaust gas from the first fuel cell device and / or cathode exhaust gas from the second fuel cell device can be supplied as oxidizer.

At least a portion of the oxidizer flow of the third fuel cell device is preferably comprised of cathode exhaust gas from the first fuel cell device and / or cathode exhaust gas from the second fuel cell device.

It may be advantageous if the fuel cell system has at least one deposition device for separating water from the exhaust gas, in particular from the cathode exhaust gas, one or more fuel cell devices.

It can be provided that the fuel cell system is an at least partially redundant fuel cell system which comprises at least two parallel and / or alternatively operable groups, in particular pairs, of fuel cell devices.

In this case, it can be provided that each group, in particular each pair, comprises a first fuel cell device which can be coupled or coupled by means of a second fuel cell device in such a way that the cathode exhaust gas can be supplied from the first fuel cell device as the oxidant flow of the second fuel cell device.

The fuel cell system according to the invention is particularly suitable as an extinguishing device and / or as a fire prevention device, by means of which in particular a closed space cathode exhaust gas of the first fuel cell device and / or cathode exhaust gas of the second fuel cell device can be fed.

The cathode exhaust gas from the first fuel cell device and / or the cathode exhaust gas from the second fuel cell device is preferably partially or completely fed to the, in particular closed, space, for example a fuel tank.

The fuel cell system according to the invention is particularly suitable for use in a vehicle and / or an aircraft, for example a passenger aircraft for carrying passengers and / or a cargo plane.

In particular, the invention relates to an aircraft which comprises a fuel cell system according to the invention.

The aircraft preferably has one or more of the features and / or advantages described in connection with the fuel cell system according to the invention.

For safety reasons, aircraft preferably provide that a fuel tank of the aircraft can be rendered inert.

It is preferably provided that the fuel tank contains liquid fuel.

A portion of the fuel tank that is not filled with liquid fuel, for example, because fuel is consumed in the course of the operation of the aircraft, is preferably filled with a gas.

To fill the fuel tank with gas, a gas is preferably used which can not form an ignitable mixture with evaporating fuel.

In particular, it can be provided that the fuel tank oxygen-poor air is supplied.

In one embodiment of the invention, it is provided that the aircraft comprises a fuel tank, to which the cathode exhaust gas of the first fuel cell device and / or the cathode exhaust gas of the second fuel cell device can be fed.

In particular, it can be provided that the fuel tank of the aircraft is coupled to the fuel cell system, in particular to the first fuel cell device and / or to the second fuel cell device, so that the cathode exhaust gas of the first fuel cell device and / or the cathode exhaust gas of the second fuel cell device can be supplied to the fuel tank.

• – Abführen von Kathodenabgas von einer Kathodenseite einer ersten Brennstoffzellenvorrichtung;
• – Zuführen von zumindest einem Teil des Kathodenabgases aus der ersten Brennstoffzellenvorrichtung zu einer Kathodenseite einer zweiten Brennstoffzellenvorrichtung als Oxidatorstrom der zweiten Brennstoffzellenvorrichtung.

A method of operating a fuel cell system that includes two or more fuel cell devices includes:

• Discharging cathode exhaust gas from a cathode side of a first fuel cell device;
• - Supplying at least a portion of the cathode exhaust gas from the first fuel cell device to a cathode side of a second fuel cell device as the oxidant stream of the second fuel cell device.

Characterized in that in the method cathode exhaust gas of the first fuel cell device is supplied as the oxidant stream of the second fuel cell device, a particularly large part of the oxidizer, in particular of the oxygen, are removed from the guided through both fuel cell devices gas stream, in particular air flow. As a result, oxygen-poor air can be produced in a particularly simple and reliable manner.

The method can be carried out in particular by means of the fuel cell system according to the invention, in particular by means of the aircraft according to the invention.

For this purpose, the fuel cell system, the extinguishing device, the fire prevention device and / or the aircraft preferably has a control device, so that the fuel cell system, the extinguishing device, the fire prevention device and / or the aircraft so can be controlled and / or regulated that one or more of the method steps of the method are feasible.

The method preferably has one or more of the features and / or advantages described in connection with the fuel cell system according to the invention, the extinguishing device, the fire prevention device and / or the aircraft according to the invention.

In one embodiment of the invention, provision is made for air to be supplied to the first fuel cell device as the oxidizer stream.

Means of the first fuel cell device is preferably generated from the Oxidatorstrom an oxygen-poor cathode exhaust gas.

Preferably, an oxygen content of the cathode off-gas of the first fuel cell device is at most about 18% by volume, more preferably at most about 16% by volume.

It is further provided that an oxygen content of the cathode exhaust gas of the second fuel cell device is at most about 14% by volume, in particular at most about 12% by volume.

It can be favorable if an additional gas flow, in particular ambient air, for example fresh air, is supplied to the cathode exhaust gas from the first fuel cell device.

In one embodiment of the invention it is provided that two fuel cell devices are provided, the cathode exhaust gas is at least partially supplied together to a third fuel cell device.

Preferably, to prevent and / or extinguish a fire in a closed space, at least a portion of a cathode exhaust gas from the first fuel cell device and / or at least a portion of a cathode exhaust gas from the second fuel cell device is supplied to the closed space.

In particular, it can be provided that, for filling a fuel tank with oxygen-poor air, at least part of a cathode exhaust gas from the first fuel cell device and / or at least part of a cathode exhaust gas from the second fuel cell device is supplied to the fuel tank.

The method is particularly suitable for filling a room, in particular a fuel tank, a transport container (cargo container), a transport space (cargo area) and / or sanitary facilities such as an aircraft, with oxygen-poor air.

• – Zuführen von Luft zu einer Kathodenseite einer ersten Brennstoffzellenvorrichtung;
• – Abführen von Kathodenabgas aus der ersten Brennstoffzellenvorrichtung;
• – Zuführen des Kathodenabgases aus der ersten Brennstoffzellenvorrichtung als Oxidatorstrom zu einer Kathodenseite einer zweiten Brennstoffzellenvorrichtung;
• – Abführen von Kathodenabgas aus der zweiten Brennstoffzellenvorrichtung;
• – Zuführen des Kathodenabgases aus der zweiten Brennstoffzellenvorrichtung zu dem Raum.

For this purpose, the following method steps are preferably carried out:

• Supplying air to a cathode side of a first fuel cell device;
• - discharging cathode exhaust gas from the first fuel cell device;
• Supplying the cathode off-gas from the first fuel cell device as an oxidant stream to a cathode side of a second fuel cell device;
• - discharging cathode exhaust gas from the second fuel cell device;
• - Supplying the cathode exhaust gas from the second fuel cell device to the room.

The fuel tank is in particular a fuel tank of an aircraft, for example a passenger aircraft or cargo aircraft.

Furthermore, the fuel cell system according to the invention, the aircraft according to the invention and / or the method may have one or more of the features and / or advantages described below:
In the fuel cell system according to the invention preferably at least two fuel cell devices are serially coupled, in particular connected in series.

Preferably, the fuel cell devices may be selectively operated in parallel or in series.

In a parallel operation of the fuel cell devices, a larger amount of low-oxygen air can be generated.

In a serial operation of the fuel cell devices, air having a lower oxygen content may preferably be obtained.

By means of the deposition device for separating water, preferably water can be separated as useful water, in particular for use during flight operation of the aircraft.

In particular, by means of the deposition device water can be separated from the exhaust gas before it is supplied to the fuel tank.

Preferably, at least one fuel cell device, in particular both fuel cell devices of a pair of fuel cell devices, is operated more than stoichiometrically. In this way it can be ensured that the water generated in the fuel cell devices is reliably removed from the fuel cell devices.

It can be provided that one or more fuel cell devices, in particular each fuel cell device, is associated with a respective deposition device for separating off water. In this way, a water content of the exhaust gas can be reliably reduced.

By means of the fuel cell system, in particular oxygen-poor air can be generated, which, in particular in the dry state, ie without or with only a low water content, comprises at most about 12% by volume of oxygen.

In particular, oxygen depleted air (ODA) can be generated.

By means of the cathode exhaust gas of the second fuel cell device, in particular a fuel tank of an aircraft can be rendered inert, without the need for separate inert gas generators (OBGGS), for example for the mechanical filtration of oxygen from the air.

In particular, the fuel cell system according to the invention forms a multifunctional energy supplier in aircraft.

Preferably, both electrical energy and water and low-oxygen air may be provided.

Preferably, a low stoichiometry is dispensable in the operation of the fuel cell devices.

It may be provided that, in particular as a function of a system load, ambient air is selectively supplied to the oxidizer flow of the second fuel cell device by means of the valve device.

Further preferred features and / or advantages of the invention are the subject of the following description and the drawings of exemplary embodiments.

In the drawings show:

1 a schematic representation of a first embodiment of a fuel cell system in which two fuel cell devices of the fuel cell system are serially operable;

2 a schematic representation of the first embodiment of the fuel cell system for illustrating a first operation;

3 one of the 2 corresponding schematic representation of the first embodiment of the fuel cell system for illustrating a second mode of operation;

4 one of the 2 corresponding schematic representation of the first embodiment of the fuel cell system for illustrating a third mode of operation; and

5 a schematic representation of a second embodiment of a fuel cell system, in which two parallel operable fuel cell devices are serially coupled to another fuel cell device.

Identical or functionally equivalent elements are provided with the same reference numerals in all figures.

One in the 1 to 4 illustrated first embodiment of a whole as 100 designated fuel cell system includes a first fuel cell device 102 and a second fuel cell device 104 ,

Each of the fuel cell devices 102 . 104 includes an oxidizer feed 106 for supplying oxidizer, in particular air, to a cathode side 103 the fuel cell device 102 . 104 and a cathode exhaust gas guide 108 for discharging cathode exhaust gas from the cathode side 103 the fuel cell device 102 . 104 ,

Further, each of the fuel cell devices includes 102 . 104 a fuel supply 107 for supplying fuel, in particular hydrogen, to an anode side 105 the fuel cell device 102 . 104 and an anode exhaust gas guide 109 for removing anode exhaust gas from the anode side 105 the fuel cell device 102 . 104 ,

The in the 1 to 4 illustrated first embodiment of the fuel cell system 100 also includes one or more fans 110 for driving an oxidizer stream and / or the cathode off-gas and one or more deposition devices 112 for separating water from the exhaust gas of the fuel cell devices 102 . 104 , in particular from the cathode exhaust gas from the fuel cell devices 102 . 104 ,

The first fuel cell device 102 and the second fuel cell device 104 are by means of a valve device 114 coupled together.

By means of the fuel cell devices 102 . 104 is in particular air from an environment 116 of the fuel cell system 100 , For example, fresh air, usable for the production of oxygen-poor air. This oxygen-poor air is especially a fuel tank 118 fed.

The fuel cell system 100 especially in one as a whole with 120 designated aircraft are used.

The plane 120 preferably includes the fuel tank 118 and the fuel cell system 100 ,

The first fuel cell device 102 and the second fuel cell device 104 of the fuel cell system 100 preferably form a group 122 , especially a couple 124 , of fuel cell devices 102 . 104 ,

The plane 120 preferably comprises at least two such groups 122 or couples 124 in order in case of malfunction of a fuel cell device 102 . 104 during operation of the aircraft 120 continue to generate reliable electrical energy, water and / or low-oxygen air.

The in the 1 to 4 illustrated first embodiment of the fuel cell system 100 works as follows:
By means of the blower 110 gets air from the environment 116 by means of the oxidizer feed 106 the cathode side 103 the first fuel cell device 102 fed.

Further, from a hydrogen reservoir 126 Fuel by means of the fuel supply 107 the anode side 105 the first fuel cell device 102 fed.

The fuel and the atmospheric oxygen react in the fuel cell device 102 with each other, so that in particular oxygen-poor air and water by means of the cathode exhaust gas guide 108 from the first fuel cell device 102 be dissipated. By means of the anode exhaust gas guide 109 In particular, excess fuel is discharged, which, for example, used elsewhere, in particular burned, can be.

By means of the valve device 114 of the fuel cell system 100 is adjustable, in particular controllable and / or adjustable, whether via the Oxidatorzuführung 106 the second fuel cell device 104 the second fuel cell device 104 Air from the environment 116 and / or cathode exhaust gas from the first fuel cell device 102 is supplied.

At the in 2 illustrated operation of the fuel cell system 100 becomes the cathode exhaust gas from the first fuel cell device 102 over the valve device 114 directly as the oxidizer stream via the oxidator feed 106 the second fuel cell device 104 fed. In this case, neither a partial flow of the cathode exhaust gas is diverted nor additional air, especially air from the environment 116 , fed.

By means of the Oxidatorzuführung 106 the second fuel cell device 104 thus becomes the cathode side 103 the second fuel cell device 104 the cathode exhaust gas from the first fuel cell device 102 fed.

In addition, by means of the fuel supply 107 the second fuel cell device 104 Fuel, especially hydrogen, to the anode side 105 the second fuel cell device 104 fed.

In the second fuel cell device 104 the fuel reacts with the still in the cathode exhaust gas from the first fuel cell device 102 contained oxygen.

The cathode exhaust gas of the second fuel cell device 104 Thus contains even less oxygen than the cathode exhaust gas of the first fuel cell device 102 ,

In particular, the oxygen content of the cathode exhaust gas, which by means of the cathode exhaust gas guide 108 from the second fuel cell device 104 is discharged, less than 12 vol .-%.

The oxygen-depleted or deoxygenated air thus obtained then becomes the fuel tank 118 of the plane 120 supplied to the non-fuel filled part of the fuel tank 118 to refill (see 2 ).

By using low-oxygen air to fill up the fuel tank 118 can be ensured that the fuel tank 118 contains no gas mixture which is ignitable.

Depending on a desired amount of oxygen-poor air and / or in dependence on the desired oxygen content of the oxygen-poor air can by means of the valve device 114 For example, a part of the means of cathode exhaust gas guide 108 from the first fuel cell device 102 discharged cathode exhaust gas dissipated and used, for example, the fuel tank 118 fed (see 3 ).

Furthermore, it can be provided that by means of a blower 110 and the valve device 114 Air from the environment 116 the cathode exhaust gas from the first fuel cell device 102 supplied and together with the cathode exhaust gas from the first fuel cell device 102 by means of the oxidizer feed 106 the second fuel cell device 104 is fed (see 4 ).

To a supply of water to the fuel tank 118 This is prevented by means of the cathode exhaust ducts 108 the fuel cell devices 102 . 104 discharged cathode exhaust dehumidifies, especially completely dried. The moisture content of the fuel tank 118 supplied oxygen-poor air can thereby be reduced greatly preferably.

The water separated from the cathode exhaust gas may preferably be used as working water in the aircraft 120 continue to be used.

An in 5 illustrated second embodiment of a fuel cell system 100 is different from the one in the 1 to 4 illustrated first embodiment essentially in that the first fuel cell device 102 and the second fuel cell device 104 not serially, but are operable in parallel. From the environment 116 is thus both the first fuel cell device 102 as well as the second fuel cell device 104 only fresh air can be supplied.

The cathode exhaust ducts 108 the first fuel cell device 102 and the second fuel cell device 104 but lead to the in 5 illustrated second embodiment of the fuel cell system 100 in a valve device 114 to which an oxidizer feed 106 a third fuel cell device 128 followed.

At the in 5 illustrated second embodiment of the fuel cell system 100 is thus the cathode exhaust gas from the first fuel cell device 102 and the cathode exhaust gas from the second fuel cell device 104 the third fuel cell device 128 fed. In particular, the cathode exhaust gas is from the first fuel cell device 102 and the cathode exhaust gas from the second fuel cell device 104 as Oxidatorstrom by means of Oxidatorzuführung 106 the third fuel cell device 128 the cathode side 103 the third fuel cell device 128 fed.

The cathode exhaust gas from the third fuel cell device 128 finally can the fuel tank 118 be supplied.

By the parallel connection of two fuel cell devices 102 . 104 according to the in 5 illustrated second embodiment of the fuel cell system 100 In particular, a large amount of low-oxygen air can be provided.

Incidentally, the in 5 illustrated second embodiment of the fuel cell system 100 in terms of structure and function with in the 1 to 4 illustrated first embodiment, so that reference is made to the above description in this respect.

Due to the fact that in all embodiments of fuel cell systems 100 Cathode exhaust gas of a fuel cell device 102 as Oxidatorstrom another fuel cell device 104 . 128 can be supplied, by means of a system which provides electrical energy and water, at the same time particularly easy to produce low-oxygen air.

In particular for providing low-oxygen air for a fuel tank 118 of an airplane 120 Thus, a separate device for the provision of oxygen-poor air is unnecessary.

LIST OF REFERENCE NUMBERS

100

The fuel cell system

102

first fuel cell device

103

cathode side

104

second fuel cell device

105

anode side

106

oxidizer

107

fuel supply

108

Cathode exhaust duct

109

Anode exhaust duct

110

fan

112

deposition apparatus

114

valve device

116

Surroundings

118

fuel tank

120

plane

122

Group of fuel cell devices

124

Pair of fuel cell devices

126

Hydrogen reservoir

128

third fuel cell device

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0596366 A1 [0002]

Claims (9)

Fuel cell system ( 100 ), in particular for the production of oxygen-poor air, comprising two or more fuel cell devices ( 102 . 104 . 128 ), wherein each fuel cell device ( 102 . 104 . 128 ) Comprises: - an oxidizer feed ( 106 ) for supplying an oxidizer stream to a cathode side ( 103 ) of the fuel cell device ( 102 . 104 . 128 ); A cathode exhaust gas duct ( 108 ) for discharging cathode exhaust gas from the cathode side ( 103 ) of the fuel cell device ( 102 . 104 . 128 ), wherein two or more fuel cell devices ( 102 . 104 . 128 ) are coupled or coupled to one another such that by means of a cathode exhaust gas guide ( 108 ) a first fuel cell device ( 102 ) that in this first fuel cell device ( 102 ) generated via the oxidator ( 106 ) a second fuel cell device ( 104 ) as oxidant flow of this second fuel cell device ( 104 ) can be fed. Fuel cell system ( 100 ) according to claim 1, characterized in that the oxidizer flow of the first fuel cell device ( 102 ) Air is. Fuel cell system ( 100 ) according to one of claims 1 or 2, characterized in that between the cathode exhaust gas guide ( 108 ) of the first fuel cell device ( 102 ) and the oxidizer feed ( 106 ) of the second fuel cell device ( 104 ) a valve device ( 114 ) by means of which the oxidizer flow for the second fuel cell device ( 104 ) a gas can be supplied. Fuel cell system ( 100 ) according to one of claims 1 to 3, characterized in that between the cathode exhaust gas guide ( 108 ) of the first fuel cell device ( 102 ) and the oxidizer feed ( 106 ) of the second fuel cell device ( 104 ) a valve device ( 114 ) is arranged, by means of which at least a part of the cathode exhaust gas of the first fuel cell device ( 102 ) is dissipatable. Fuel cell system ( 100 ) according to one of claims 1 to 4, characterized in that the fuel cell system ( 100 ) at least a third fuel cell device ( 128 ), which cathode exhaust gas from the first fuel cell device ( 102 ) and / or cathode exhaust gas from the second fuel cell device ( 104 ) can be supplied as Oxidatorstrom. Fuel cell system ( 100 ) according to one of claims 1 to 5, characterized in that the fuel cell system ( 100 ) at least one deposition device ( 112 ) for separating water from the exhaust gas of one or more fuel cell devices ( 102 . 104 . 128 ). Fuel cell system ( 100 ) according to one of claims 1 to 6, characterized in that the fuel cell system ( 100 ) an at least partially redundant fuel cell system ( 100 ) which has at least two groups which can be operated in parallel and / or alternatively ( 122 ), especially couples ( 124 ), of fuel cell devices ( 102 . 104 . 128 ). Plane ( 120 ) comprising a fuel cell system ( 100 ) according to one of claims 1 to 7. Plane ( 120 ) according to claim 8, characterized in that the aircraft ( 120 ) a fuel tank ( 118 ), to which the cathode exhaust gas of the first fuel cell device ( 102 ) and / or the cathode exhaust gas of the second fuel cell device ( 104 ) can be fed.

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