EP3776706A1

EP3776706A1 - Fuel cell system

Info

Publication number: EP3776706A1
Application number: EP19718267.8A
Authority: EP
Inventors: Jochen Braun
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2018-04-09
Filing date: 2019-04-05
Publication date: 2021-02-17
Also published as: JP2021517723A; DE102018205288A1; CN111937202A; JP7122387B2; WO2019197278A1

Abstract

The invention relates to a fuel cell system (1) comprising a fuel cell (2), an air supply line (3) for supplying ambient air into the fuel cell (2), and an exhaust air line (4) for discharging the reacted ambient air from the fuel cell (2). A compressor (5) is arranged in the air supply line (3). At least one further consumer (21, 22, 23) of ambient air is arranged parallel to the fuel cell (2) downstream of the compressor (5).

Description

description

title

The fuel cell system

State of the art

Fuel cell systems are known from the prior art, for example from DE 10 2004 051 359 B4. The known fuel cell system comprises a fuel cell, an air supply line for supplying ambient air into the fuel cell and an exhaust duct for discharging the reacted ambient air from the fuel cell. In the air supply line, a compressor for compressing the ambient air is arranged on.

Disclosure of the invention

The object of the invention is to make the fuel cell system, in particular the compression or conveying the ambient air, more efficient. This is achieved in that the compressor is designed so that it can supply another consumer with ambient air in addition to the fuel cell.

For this purpose, the fuel cell system comprises a fuel cell, a Luftzuführungslei device for supplying ambient air into the fuel cell and an exhaust duct for discharging the reacted ambient air from the fuel cell. A compressor is arranged in the air supply line. Downstream of the compressor, at least one further consumer of ambient air is arranged parallel to the fuel cell.

This allows the compressor to supply both the fuel cell and the other consumers cher with ambient air. Other consumers may be, for example, an air conditioner, a cooling system, a blocking air system or a dilution for the anode side of the fuel cell. Preferably, each additional consumer is assigned a control valve, so that all consumers can be supplied with ambient air as needed. In preferred embodiments, the compressor is arranged on a shaft which can be driven by a drive unit. The drive unit is advantageously an electric motor. As a result, the speed of the compressor, which is preferably designed as a radial runner, can be controlled very dynamically, so that the mass flow of ambient air conveyed by it can be set very quickly to the respective requirements.

In advantageous developments, an exhaust gas turbine is arranged in the exhaust air line, wherein the exhaust gas turbine is preferably arranged on the shaft. As a result, the compressor is driven by the exhaust gas turbine, preferably supported by the electric motor. The existing (exhaust) energy in the exhaust air is thus reused to promote the ambient air.

In advantageous embodiments of the fuel cell is associated with a supply valve, and the at least one further consumer, a control valve. As a result, the air mass flow in the air supply line can be divided as needed to the fuel cell and the other consumers. Preferably, the supply valve and the control valve are designed as proportional valves and arranged upstream of the fuel cell and the other consumer.

Preferably, a further compressor is arranged in the air supply line. The additional compressor can be connected in parallel or in series with the compressor. In Ausfüh ments with special control valve assemblies, the other compressor may be connected to the compressor so that the air supply is made in the fuel cell either two stages condensed, or one of the two compressors supplied the fuel cell in one stage. Particularly in the case of a fuel cell system in a vehicle, the additional compressor can also be taken from an adjacent system, for example from the air conditioning system. Thus, the already existing in the vehicle further compressor is used particularly effectively.

In advantageous embodiments, the further compressor is connected to the compressor in series GE and a supply valve is disposed between the compressor and the further compressor. By the supply valve of the other compressor and the fuel cell on the one hand and the other consumers with their associated control valves on the other hand are connected in parallel. The supply of other consumers through the compressor is done so with single-stage compressed ambient air. The supply of the fuel cell takes place in two stages - by compressors and other compressors - compressed ambient air.

In advantageous developments, a compressor bypass valve is parallel to the supply valve and the other United dense arranged. This results in a parallel circuit of the other consumers on the one hand and the parallel circuit of Verdichterby pass valve and other compressor with supply valve on the other. The compressor bypass valve opens and thus closes a single-stage compressed flow path over the United denser to the fuel cell. The supply valve opens and closes the two-stage compaction flow path through the compressor and the other compressor to the fuel cell. The fuel cell can therefore be supplied in this embodiment with both one-stage and two-stage compressed ambient air.

In other advantageous developments, a compressor bypass valve is arranged parallel to the supply valve and the United denser. This results in a parallel circuit of the compressor bypass valve and the compressor with supply valve. The supply of the fuel cell can therefore be done via the path compressor bypass valve and other Ver denser, or via the path compressor, supply valve and other compressor. The supply of the fuel cell can thus be carried out both in one stage and two stages. The other consumers are supplied by the compressor in this embodiment. Downstream of the compressor there is thus a branch point to the other consumers and to the supply valve.

In alternative advantageous embodiments, the further compressor is connected in parallel to the United denser. The compressor is associated with a supply valve, and the other United dense a compressor bypass valve. The supply of the fuel cell with ambient air can be done both via the compressor with supply valve and via the other compressor with compressor bypass valve. Are both control valves open, the total mass flow of ambient air into the fuel cell results from the funded by compressor and further compressor mass flows, minus the Mas senstrom to the other consumers, which are also fed by the compressor. However, the supply of the fuel cell with ambient air can also redun dant made either by the compressor or by the other compressor who the. In the embodiments with a parallel circuit of compressor and further compressor both compressors can be driven in each case with an exhaust gas turbine and / or with a drive unit, wherein at least one of the two compressors should have a drive unit.

In preferred developments, the further compressor is connected to the compressor by means of valves such that both the fuel cell and the at least one further consumer can be supplied with ambient air both from the compressor and from the further compressor. The compressor and the further compressor are arranged parallel to it. Downstream of a cross-circuit of the valves to the fuel cell fuel cell and the other consumers is arranged. The cross-circuit consists of the supply valve, which is associated with the compressor from another compressor bypass valve, which is associated with the further compressor, from a further to supply valve, which is associated with the fuel cell, each consisting of a control valve, which is assigned to a further consumer , And from the compressor bypass valve wel Ches is located at the intersection of these four valves. This makes the fuel cell system very flexible; Both the fuel cell and the other consumers can be provided with any mass flow components of compressor and further compressor ver. In this case, the compressor and the further compressor are each configured redundantly for the fuel cell and for the other consumers. Fuel cell and far re consumers can thus be supplied from both the compressor and the other United denser and thus also jointly from both compressors with ambient air.

In particularly preferred embodiments, the further compressor is switchable to the compressor both in series and in parallel. As a result, the ambient air for the fuel cell can be compressed both one-stage and two-stage, and the single-stage compression is designed to be redundant at the same time.

In advantageous developments, the at least one further consumer can also be supplied with ambient air by the further compressor. Thus, the single-stage compaction is running redundant device for the other consumers.

The fuel cell system may preferably be configured to drive a drive unit of a motor vehicle. Preferably, the vehicle then has the fuel cell system according to one of the previous embodiments and a driver's cab on, with another consumer is designed for ventilation of the cab.

As a result, the compressor supplies the driver's cab with ambient air, if necessary heated or cooled.

Brief description of the drawings

Further optional details and features of the invention will become apparent from the following description of preferred embodiments, which are shown cal statically in the figures.

Show it:

FIG. 1 shows schematically a fuel cell system according to the invention,

FIG. 2 shows schematically another fuel cell system according to the invention,

FIG. 3 schematically shows yet another fuel cell system according to the invention,

FIG. 4 schematically shows yet another fuel cell system according to the invention,

FIG. 5 schematically shows yet another fuel cell system according to the invention,

FIG. 6 schematically shows yet another fuel cell system according to the invention,

FIG. 7 schematically shows yet another fuel cell system according to the invention.

Detailed description of the invention

FIG. 1 schematically shows a fuel cell system 1 according to the invention. The fuel cell system 1 comprises a fuel cell 2 with a cathode and an anode, an air supply line 3 and an exhaust air line 4 in the cathode path and a compressor 5, in preferred embodiments also an exhaust gas turbine 6.

The fuel cell 2 is a galvanic cell, the chemical reaction energy of a not shown fuel supply line fuel supplied in the anode path and an oxidant in the cathode path converts into electrical energy, wherein in the embodiment shown here ambient air 10 is used as the oxidant, which is supplied via the air supply line 3 by means of the compressor 5 of the fuel cell 2. The fuel may preferably be hydrogen or methane or methanol Me. The fuel cell 2 is preferably set up to drive a drive unit of a motor vehicle. For example, the electrical energy generated by the fuel cell 2 drives an electric motor of the motor vehicle.

The compressor 5 is arranged in the air supply line 3. The exhaust gas turbine 6 is arranged in the exhaust air line 4. The compressor 5 and the exhaust gas turbine 6 are vorzugswei se mechanically connected via a shaft 7 and additionally driven by a drive unit 11 electrically. The exhaust gas turbine 6 thus serves to support the Antriebssein unit 11 for driving the shaft 7 and the compressor 5. The compressor 5, the shaft 7, the exhaust gas turbine 6 and designed as an electric motor drive unit 11 form together to an electric turbocompressor.

In advantageous developments, the ambient air 10 is filtered in the air supply line 3 upstream of the compressor 5 by a filter 8 and downstream of the United poet 5 cooled by a heat exchanger 9.

According to the invention, further consumers (21, 22, 23) of ambient air are connected in parallel with the fuel cell 2 downstream of the fuel cell 2. In advantageous developments, these consumers (21, 22, 23) can be supplied with ambient air in any desired manner by means of an associated control valve (21a, 22a, 23a). Likewise, the supply of ambient air to the fuel cell by means of an associated supply valve (2 a) can be throttled or even interrupted. Preferably, the Steuerventi le (2a, 21a, 22a, 23a) leads out as proportional valves or as shut-off valves out.

Other consumers (21, 22, 23) of ambient air may be, for example: interior ventilation / air conditioning of the motor vehicle,

Cooling of the drive unit 11 and the compressor 5,

Cooling the power electronics of the compressor 5,

Cooling the bearings of the shaft 7,

Sealing air for seals, Air for radial bearings or axial bearings of the shaft 7,

Air cooling of a battery of the motor vehicle,

Air cooling of a drive electric motor and / or the power electronics of a vehicle, in particular for motorized vehicles for the low-price segment (for example in Asia),

Air for diluting a purge drain of the anode path of the fuel cell system. 1

The compressor 5 thus supplies several consumers (2, 21, 22, 23) with ambient air.

Preferably, the compressor 5 is even the only air supply unit in the motor driving convincing and further includes an electric motor and power electronics. This results in the following advantages for the motor vehicle:

- The number of start-stops of the compressor 5 and the drive unit 11 is significantly reduced due to the multiple use.

- Due to the associated reduced demands on the bearings of the shaft 7 cheaper bearing variants can be made possible.

Due to the large space requirement, fuel cell systems (transducers chemical energy into electrical energy) including tank for fuel or fuel (for example hydrogen) often have disadvantages compared to other drive types. A high Integrati onsdichte the air conveyor / compression systems can be achieved by the invention who the and thus reduce the required space again.

- Fuel cell systems are currently associated with high costs. The connection to several consumers 2, 21, 22, 23 to the compressor 5 offers a possibility to reduce costs.

2 schematically shows another fuel cell system 1 according to the invention. In the following, the differences to the embodiment according to FIG.

The fuel cell system 1 has a turbomachine 100 with the drive unit 11 and a two-stage compressor; the two-stage compressor comprises the compressor 5 and a further compressor 52, which are arranged in the embodiment of Figure 2 on the common shaft 7. Furthermore, the optional exhaust gas turbine 6 is arranged on the shaft 7. The compressor 5 and the further compressor 52 are connected in series in the air supply line 3 to the fuel cell 2. Between the two compressors 5, 52 branches out at a branch point 101, the parallel circuit

Series circuit supply valve 2a, another compressor 52, heat exchanger 9, fuel cell 2,

further consumer 21 with control valve 21a,

yet another consumer 22 with control valve 22 a and

yet another consumer 23 with a control valve 23a.

As a result, the fuel cell 2 is supplied with ambient air at comparatively high pressure, since it is compressed in two stages by the two compressors 5, 52. The other consumers 21, 22, 23, however, ambient air is supplied at a lower pressure, since it is branched off after the 1-stage compression by the compressor 5 at the branch point 101. The advantages for demand-based air supply of the consumer with different pressure levels, in particular taking into account the energy optimization will be explained in more detail below.

In further embodiments, the fuel cell system 1 has a bypass valve 2 b between the air supply line 3 and the exhaust air line 4 in order to be able to bypass the cathodic path of the fuel cell 2. Furthermore, a water separator 41 may be arranged in the exhaust duct 4 upstream of the exhaust gas turbine 6 in order to protect the exhaust gas turbine 6 from droplet impact.

3 schematically shows yet another fuel cell system 1 according to the invention. In the following, the differences to the embodiment according to FIG. 2 will be discussed essentially.

The fuel cell system 1 can supply the fuel cell 2 with both 1-stage and 2-stage compressed ambient air.

For this purpose, the following parallel circuit branches off after the compressor 5 at the branching point 101

Series connection supply valve 2a, further compressor 52, heat exchanger 9, compressor bypass valve 2c,

further consumer 21 with control valve 21a,

yet another consumer 22 with control valve 22 a and yet another consumer 23 with a control valve 23a.

The parallel circuit of supply valve 2a, further compressor 52 and heat exchanger 9 on the one hand and compressor bypass valve 2c on the other hand, is brought together before the fuel cell 2 as the. Thus, for supplying the fuel cell 2 with ambient air, the following valve positions of supply valve 2a and compressor bypass valve 2c are provided:

If the high pressure level of a 2-stage compression is required for the fuel cell 2, then the supply valve 2a is opened and the compressor bypass valve 2c closed.

If only a lower pressure is required for the fuel cell 2 in part-load operation, then the supply valve 2a is closed and the compressor bypass valve 2c is opened. The fuel cell 2 is then supplied only via the compressor 5. The heat exchanger 9 can be bypassed in this operating point because the tempera ture of the compressed air after the compressor 5 without further compression is less than or equal to the permissible inlet temperature of the ambient air in the fuel cell 2 and in the fuel cell stack.

If no ambient air is required for the fuel cell 2, then both the supply valve 2a and the compressor bypass valve 2c are closed.

The advantages for demand-based air supply of consumers with different pressure levels, in particular taking into account the energy optimization will be explained in more detail wei ter below.

FIG. 4 schematically shows yet another fuel cell system 1 according to the invention. In the following, the differences to the embodiment according to FIG. 3 will be discussed essentially.

The fuel cell system 1 can supply the fuel cell 2 with both 1-stage and 2-stage compressed ambient air. The single-stage compression takes place, however, by the further compressor 52, which is arranged in the embodiment of Figure 4 together with the exhaust gas turbine 6 on the shaft 7.

The compressor bypass valve 2 c is connected in parallel to the compressor 5, but can also be omitted in alterna tive embodiments, so that the ambient air must always flow through the compressor 5. Downstream of the compressor 5 is the branch point 101 is arranged, at which the path splits into a parallel connection of the further consumers 21, 22, 23 (including the associated control valves 21a, 22a, 23a) and the supply valve 2a. The paths of compressor bypass valve 2c and supply valve 2a lead together again and open into the further compressor 52, from where the fuel cell 2 is fed.

With open supply valve 2a and closed compressor bypass valve 2c so takes place with a two-stage compression of the ambient air for the fuel cell 2, example, for a high power output of the fuel cell 2. Furthermore, this circuit Ver can also be used to the exhaust gas turbine 6 and the other Compressor 52 to de-ice: If, for example, the shaft 7 can not be started due to icing of the gas turbine from 6, can on the compressor 5 ambient air, which can optionally also be preheated, on the standing further Ver denser 52 in the cathode path or in the Air supply line 3 are introduced, which warms up in the fuel cell 2 and then the exhaust gas turbine 6 enteist or makes common again. Thereafter, the unit of further compressor 52 and exhaust turbine 6, which is optionally driven by an electric motor can be started.

This eliminates additional measures such as heaters on the exhaust turbine 6.

Furthermore, in the event of a failure of the further compressor 52, which is preferably the main compressor for the fuel cell 2, a partial load operation of the fuel cell 2 is possible, in which the compressor 5 conducts a mass air flow into the air supply line 3.

In addition, the number of start-stop operations of the further compressor 52 can be reduced by keeping it switched off at low drive powers (for example stop-and-go traffic, congestion, slow city traffic) and operation of the fuel cell 2 in the lower part load Area is effected by an air mass flow of the compressor 5. By thus reduced demands on the bearings of the shaft 7 kos tengünstigere storage versions can be made possible. In addition, an energetic advantage can optionally be achieved by the partial load operation with the additional compressor 52 switched off.

5 shows schematically yet another fuel cell system 1 according to the invention, in which the compressor 5 and the further compressor 52 in the air supply line 3 the fuel cell 2 are connected in parallel. The compressor bypass valve 2c is arranged in the partial path of the further compressor 52, and the supply valve 2a in the partial path of the compressor 5 to the fuel cell 2. Downstream of the compressor 5 ver branches the flow of ambient air to the supply valve 2a on the one hand and to the other consumers 21st , 22 on the other hand.

The further consumers 21, 22 are thus supplied by the compressor 5 with ambient air. Depending on the position of the valves, the fuel cell 2 can be supplied with ambient air from the compressor 5, from the further compressor 52 or from both compressors 5, 52 simultaneously - in parallel.

When the compressor bypass valve 2c is closed and the supply valve 2a is open, the further compressor is bypassed and the fuel cell 2 is supplied by the compressor 5.

When the compressor bypass valve 2c and closed supply valve 2a he follows the supply of the fuel cell 2 through the other compressor 52nd

When the compressor bypass valve 2c and open supply valve 2a is open, the supply of the fuel cell 2 through the compressor 5 and further compaction ter 52. This circuit is used in particular at a high mass flow requirement of the fuel cell 2.

Also in the embodiment of Figure 5, as in all other embodiments, in the air line 4 from the water separator 41 and / or the exhaust gas turbine 6 may be arranged. Depending on the design of the fuel cell system 1, the exhaust gas turbine 6 may be designed to drive the compressor 5 or to drive the further compressor 52. Furthermore, the fuel cell 2 and the exhaust gas turbine 6 can also have bypasses, in particular for a start-up or de-icing operation of the fuel cell system 1.

The control valves 21a, 22a may be designed as air dampers and used at various positions for the division of the air mass flow or for pressure division who the. Depending on the design variant (air usage and operating strategy), the louvers can be passive - for example, as check valves - or active - in particular with control options - be executed. In a multi-stage compression, depending on the pressure and temperature level, a heat exchanger can be used as an intercooler between the two compression stages.

6 schematically shows yet another fuel cell system 1 according to the invention, in which the compressor 5 and the further compressor 52 in the air supply line 3 of the fuel cell 2 are connected in parallel. In the embodiment of FIG. 6, the compressor 5 and the exhaust gas turbine 6 are arranged on the shaft 7. In the following, we will essentially discuss the differences from the embodiment of FIG.

The compressor 5 and the further compressor 52 are arranged in the embodiment of Figure 6 in parallel in the air supply line 3, that they can supply fol lowing customers depending on the valve positions with ambient air:

Individually or together the fuel cell 2 and / or

Individually or together the other consumers 21, 22, 23.

In this case, for example, the following operating situations are possible:

The compressor 5 supplies the fuel cell 2 and

the additional compressor 52 supplies the further consumers 21, 22, 23.

The compressor 5 supplies the other consumers 21, 22, 23, and the fuel cell 2 is switched off or runs in oxygen depletion.

The additional compressor 52 supplies the fuel cell 2, and the other consumers 21, 22, 23 are switched off or have no need for ambient air.

The further compressor 52 supplies the further consumers 21, 22, 23, and the fuel cell 2 is switched off or runs in oxygen depletion

For this purpose, the supply valve 2a, the compressor bypass valve 2c, the control valves 21a, 22a, 23a of the further consumers 21, 22, 23, another supply valve 2d and another compressor bypass valve 2e are arranged in a crossing position:

Downstream of the compressor 5, the supply valve 2a is arranged.

Downstream of the supply valve 2a, the branch point 101 is arranged, wherein the flow path splits in a direction to the fuel cell 2 and in a direction to the other consumers 21, 22, 23.

Downstream of the further compressor 52, the further compressor bypass valve 2e is arranged.

Downstream of the further compressor bypass valve 2 e, a further branching point 101 b is arranged, wherein the flow path splits in a direction to the fuel cell 2 and in a direction to the other consumers 21, 22, 23. Between the two branch points 101, 101 b, the compressor bypass valve 2 c is arranged, which is thus preferably in both directions (for fuel cell 2 and to the other consumers 21, 22, 23) can be flowed through.

Downstream of the branching point 101 in the direction of the fuel cell 2, the further supply valve 2 d is arranged.

Downstream of the further branch point 101b in the direction of the wide Ren consumers 21, 22, 23, the associated control valves 21a, 22a, 23a are arranged in parallel.

7 shows schematically yet another fuel cell system 1 according to the invention, in which the compressor 5 and the further compressor 52 in the air supply line 3 of the fuel cell 2 can be connected both in series and in parallel. For this purpose downstream of the branching point 101, a parallel circuit of the compaction ter 5 and the compressor bypass valve 2c is arranged, which downstream of the further downstream by means of the supply valve 2a further compressor 52 can be closed again, wherein alternatively the compressor bypass valve 2c can also be omitted, especially at approximately lossless flow the stationary compressor 5. In further, also complementary alternatives, the parallel circuit can also only downstream of the further compressor 52 by means of the further supply valve 2 d closed again who the.

This results in the supply of the fuel cell 2 with ambient air as a function of the valve positions of compressor bypass valve 2c, supply valve 2a and wei terem supply valve 2d the following options:

Single-stage compression by the compressor 5: closed compressor bypass valve 2c, closed supply valve 2a, open further supply valve 2d single-stage compression by the other compressor 52: open Kompichterby pass valve 2c, closed supply valve 2a, closed further supply valve 2d

Two-stage compression by the compressor 5 and the other compressor 52: closed compressor bypass valve 2c, open supply valve 2a, closed nes further supply valve 2d

Single-stage compression with increased mass flow through parallel connection of first compressor 5 and second compressor 52: open compressor bypass valve 2c, closed supply valve 2a, open further supply valve 2d The supply valve 2 a is preferably only able to flow through in the direction of the further compressor 52, and the further supply valve 2 d only in the direction of the fuel cell 2.

In this embodiment, depending on an exhaust gas turbine 6, the compressor 5 and the wide Ren compressor 52 drive. Any number of further consumers 21, 22, 23 can be supplied with ambient air by the compressor 5.

In the embodiments of Figure 5, Figure 6 and Flg ^ Z is a redundant air supply, so probably for the fuel cell 2 as well as for the other consumers 21, 22, 23, sicherge provides, if the supply valve 2a (Figure 5) or the compressor bypass valve 2c (FIG. 6) or the further supply valve 2d (FIG. 7) can be flowed through correspondingly in both directions. The availability of the vehicle with the fuel cell system 1 can be increased, which is particularly advantageous in fully automated vehicles or commercially used vehicles. As a result, safety and legal requirements can be better met (for example, the dilution of hydrogen or the protection of the ventilation).

In preferred developments of the different embodiments, the two air conveyor systems, so the compressor 5 and the other compressor 52 can fall back on under different sources of energy (for example, the compressor 5 to 12 V or 48V and the other compressor 52 on high-voltage electrical system), which also has a Re dundance in the energy supply results.

Furthermore, if appropriate, in the lower partial load operation of the Brennstoffzellensys system 1, the air supply to the fuel cell 2 via the additional compressor 52, which must be in operation anyway for other tasks (for example, as a fresh air blower for vehicle air conditioning). The compressor 5 can be completely switched off in such Betriebszustän. Examples include: stop-and-go traffic, traffic jams, slow city traffic, auxiliary heating / warm-up phase. By this measure, the fuel cell system 1 is energetically optimized. Furthermore, this minimizes the number of start-stops of the compressor 5, so that its wear parts are less stressed bean. For example, due to the reduced demands on the bearings of the shaft 7 then correspondingly cheaper storage variants can be used. Wei terhin, the dynamic requirements of the compressor 5 can be reduced if at idle or at lower part-load operation of the further compressor 52 takes over the task of air supply for the fuel cell 2.

This directly affects the design of the drive unit 11 and the Power electronics for the compressor 5. The drive unit 11 for the compressor 5 is not shown in Figures 4-7. In preferred embodiments, the compressor 5 nevertheless has in each case the drive unit 11 in order, on the one hand, to be able to drive the shaft 7 independently of the exhaust gas turbine 6 and, on the other hand, to be able to cover all operating situations, in particular during the starting phase.

In the embodiment according to FIG. 3, due to the control valve arrangements, both redundancy and two-stage compression can be realized, for example, when the compressor 5 and the further compressor 52 are not arranged on a common shaft. This can also be used to optimize the fuel cell system 1 (Wir kungsgrad, drive unit 11, power electronics).

In versions with the exhaust gas turbine 6 results for the freeze start or cold start advantages: In icing of the exhaust gas turbine 6 (bearing and / or impeller) can

by the further coupled air system - ie the system which does not hang on derglei Chen wave 7 as the exhaust gas turbine, depending on the design of the compressor 5 or the other compressor 52 - air into the air supply line 3 and into the exhaust duct 4 is turned on, there warmed up and then the exhaust gas turbine 6 are supplied, so that it is de-iced. After that, the compressor 5 or the further compressor 52 can be started with the exhaust gas turbine 6 connected to it in a rotationally fixed manner. This eliminates additional measures such as heaters on the exhaust turbine. 6

As valves 2 a, 2 b, 2 c, 2 d, 2 e, 21 a, 22 a, 23 a proportional valves ge can be selected if necessary, so that the mass flows of ambient air to the fuel cell 2 and the other consumers 21, 22, 23 are set virtually arbitrarily in the ideal case can. However, it is also possible to use shut-off valves or passive valves 2a, 2b, 2c, 2d, 2e, 21a, 22a, 23a (for example non-return flaps), which then open and close on the basis of relative pressures.

Claims

claims

1. Fuel cell system (1) with a fuel cell (2), an air supply line

(3) for supplying ambient air into the fuel cell (2) and an exhaust duct

(4) for discharging the reacted ambient air from the fuel cell (2), wherein a compressor (5) is arranged in the air supply pipe (3)

characterized in that

downstream of the compressor (5) parallel to the fuel cell (2) at least one further consumer (21, 22, 23) is arranged by ambient air.

2. Fuel cell system (1) according to claim 1

characterized in that

the compressor (5) on one of a drive unit (11) driven shaft (7) is arranged on.

3. Fuel cell system (1) according to claim 1 or 2

characterized in that

an exhaust gas turbine (6) is arranged in the exhaust air line (4), wherein the exhaust gas turbine (6) is preferably arranged on the shaft (7).

4. Fuel cell system (1) according to one of claims 1 to 3

characterized in that the fuel cell (2) is associated with a supply valve (2a) and the at least one further consumer, a control valve (21a, 22a, 23a).

5. Fuel cell system (1) according to one of claims 1 to 4

characterized in that

another compressor (52) in the air supply line (3) is arranged.

6. Fuel cell system (1) according to claim 5

characterized in that

the further compressor (52) is connected in series with the compressor (5).

7. Fuel cell system (1) according to claim 6

characterized in that

a supply valve (2a) is arranged between the compressor (5) and the further compressor (52).

8. Fuel cell system (1) according to claim 7

characterized in that

parallel to the supply valve (2a) and the further compressor (52) a Verdichterby pass valve (2c) is arranged.

9. Fuel cell system (1) according to claim 7

characterized in that

a compressor bypass valve (2c) is arranged parallel to the supply valve (2a) and the compressor (5).

10. Fuel cell system (1) according to claim 5

characterized in that

the further compressor (52) is connected in parallel to the compressor (5).

11. Fuel cell system (1) according to claim 10

characterized in that

the compressor (5) is associated with a supply valve (2a) and that the further Ver denser (52) is associated with a compressor bypass valve (2c).

12. Fuel cell system (1) according to claim 10 or 11

characterized in that

the further compressor (52) is connected to the compressor (5) by means of valves (2a, 2c, 2d, 2e) in such a way that both the fuel cell (2) and the at least one further consumer (21, 22, 23) both from the compressor (5) and from the further compressor (52) can be supplied with ambient air.

13. Fuel cell system (1) according to one of claims 5 to 12

characterized in that

the further compressor (52) is switchable to the compressor (5) both in series and in parallel.

14. Fuel cell system (1) according to one of claims 5 to 13

characterized in that

the at least one further consumer (21, 22, 23) can also be supplied with ambient air from the further compressor (52).

15. Vehicle with a fuel cell system (1) according to one of claims 1 to 14 and with a driver's cab, wherein a further consumer (21, 22, 23) is designed for ventilation of the driver's cab.