Fuel cell system

Abstract

Fuel cell system (10), with several fuel cells connected in parallel (11), with a hydrogen supply unit (12) which is set up to supply the fuel cells (11) with hydrogen, with an air supply device (13) which is configured to supply the fuel cells (11) with air, with an exhaust gas discharge device (14) which is designed to discharge exhaust gas from the fuel cells (11), with a turbocharger (15) comprising a compressor (16) and a turbine (17), wherein the compressor (16) is configured to compress supply air for the fuel cells (11) upstream of the supply air supply device (13), and wherein the turbine (17) is configured to expand exhaust gas from the fuel cells (11) downstream of the exhaust gas discharge device (14) and to use the energy obtained thereby to drive the compressor (16), with an electric machine (19) and / or a further turbine (26), wherein the electric machine (19) and / or the further turbine (26) is configured to drive the compressor (16) of the turbocharger (15) to assist the turbine (17) of the same or a further compressor (24).

Description

[0001] The invention relates to a fuel cell system.

[0002] DE 10 2018 112 454 A1 discloses a fuel cell system with a fuel cell, wherein the fuel cell generates electricity from hydrogen and air. Supply air can be provided to the fuel cell via a compressor of a turbocharger, while exhaust gas from the fuel cell is routed through a turbine of the turbocharger, which is coupled to the compressor via a shaft. The mechanical energy generated during the expansion of the exhaust gas in the turbine can be used to drive the compressor. An electric machine, arranged either on the compressor side or on the turbine side of the turbocharger, assists the turbine in driving the compressor, since the exhaust gas enthalpy of a fuel cell is generally insufficient to adequately compress the required supply air.

[0003] DE 10 2018 112 451 A1 discloses a further fuel cell system comprising a fuel cell and a turbocharger, which includes a compressor and a turbine. Furthermore, a further compressor is disclosed for pre-compressing the supply air for the fuel cell upstream of the turbocharger's compressor. This further compressor of the fuel cell system can be part of another turbocharger.

[0004] Based on this, the present invention aims to create a novel fuel cell system.

[0005] This problem is solved by a fuel cell system according to claim 1.

[0006] The fuel cell system according to the invention comprises several fuel cells connected in parallel. The fuel cell system according to the invention further comprises a hydrogen supply device configured to supply the fuel cells with hydrogen. The fuel cell system according to the invention further comprises an air supply device configured to supply the fuel cells with air. The fuel cell system according to the invention further comprises an exhaust gas removal device configured to remove exhaust gas from the fuel cells.The fuel cell system according to the invention further comprises a turbocharger including a compressor and a turbine, wherein the compressor is configured to compress supply air upstream of the supply air supply device, and wherein the turbine is configured to expand exhaust gas downstream of the exhaust gas discharge device and to use the energy gained in this process to drive the compressor. The fuel cell system according to the invention further comprises an electric machine and / or a further turbine, wherein the electric machine and / or the further turbine is configured to drive the compressor of the turbocharger to assist the turbine of the same or a further compressor.

[0007] The fuel cell system according to the invention comprises several fuel cells connected in parallel, as well as a hydrogen supply unit, an air supply unit, and an exhaust gas removal unit in addition to the turbocharger. The hydrogen supply unit of the fuel cell system according to the invention is configured to supply the fuel cells connected in parallel with hydrogen. The air supply unit of the fuel cell system according to the invention is configured to supply the fuel cells connected in parallel with air. The exhaust gas removal unit of the fuel cell system according to the invention is configured to remove exhaust gas from the fuel cells connected in parallel. The fuel cell system according to the invention allows for the efficient operation of several fuel cells connected in parallel with a simple design.

[0008] Preferably, the air supply system for all fuel cells connected in parallel has a common air supply module, and the exhaust system for all fuel cells connected in parallel has a common exhaust system module. Alternatively, the air supply system for each of the fuel cells connected in parallel has an individual air supply module, and the exhaust system for each of the fuel cells connected in parallel has an individual exhaust system module. In particular, if the air supply system and the exhaust system for each of the fuel cells connected in parallel have an individual air supply module and an individual exhaust system module, respectively, the fuel cell system is arbitrarily scalable with respect to the number of fuel cells connected in parallel.

[0009] Preferably, the compressor and turbine of the turbocharger are coupled via a shaft, with the electric machine coupled to this shaft either on the compressor side, on the turbine side, or between the compressor and the turbine. Alternatively, the compressor and turbine of the turbocharger are coupled via a shaft, with the electric machine coupled to the additional compressor and / or the additional turbine to the additional compressor. This allows for particularly efficient operation of the fuel cell system, as the expansion enthalpy of the hydrogen can also be used to compress the supplied air.

[0010] Preferred embodiments of the invention are described in the dependent claims and the following description. Exemplary embodiments of the invention are explained in more detail with reference to the drawings, without being limited thereto. These show: Fig. 1 a schematic representation of a first fuel cell system according to the invention, Fig. 2 a schematic representation of a second fuel cell system according to the invention, Fig. 3 a schematic representation of a third fuel cell system according to the invention, Fig. 4 a schematic representation of a fourth fuel cell system according to the invention, Fig. 5 a schematic representation of a fifth fuel cell system according to the invention, Fig. 6 a schematic representation of a sixth fuel cell system according to the invention, Fig. 7 a schematic representation of a seventh fuel cell system according to the invention, Fig. 8 a schematic representation of an eighth fuel cell system according to the invention, Fig. 9 a schematic representation of a ninth fuel cell system according to the invention, Fig. 10 a schematic representation of a tenth fuel cell system according to the invention, Fig. 11 a schematic representation of an eleventh fuel cell system according to the invention, Fig. 12 a schematic representation of a twelfth fuel cell system according to the invention.

[0011] The invention presented here relates to a fuel cell system 10. Such a fuel cell system 10 serves to generate electricity from hydrogen gas.

[0012] Fig. Figure 1 shows an embodiment of a fuel cell system 10 according to the invention. The fuel cell system 10 has several fuel cells 11 connected in parallel.

[0013] Each of the fuel cells 11 can be supplied with hydrogen gas from a hydrogen supply unit 12, the fuel cells 11 being connected in parallel with respect to the hydrogen supply via the hydrogen supply unit 12.

[0014] The fuel cell system also has an air supply device 13. The air supply device 13 is configured to supply the parallel-connected fuel cells 11 with supply air, the multiple fuel cells 11 also being connected in parallel with respect to the air supply.

[0015] During the combustion of hydrogen gas in the presence of supply air, exhaust gas is produced in the fuel cells 11. The fuel cell system 10 has an exhaust gas discharge device 14, which is designed to discharge exhaust gas from the parallel-connected fuel cells. The fuel cells 11 are also connected in parallel with respect to exhaust gas discharge via the exhaust gas discharge device 14.

[0016] The fuel cell system 10 according to the invention further comprises a turbocharger 15, which includes a compressor 16 and a turbine 17. The compressor 16 is configured to compress the supply air for the fuel cells 11 upstream of the air supply device 13. The turbine 17 of the turbocharger 15 is configured to expand the exhaust gas from the fuel cells 11 downstream of the exhaust gas discharge device 14. The compressor 16 and the turbine 17 of the turbocharger 15 are coupled via a shaft 18, whereby the mechanical energy gained during the expansion of the exhaust gas in the turbine 17 is used to drive the compressor 16 of the turbocharger 15.

[0017] The fuel cell system 10 of the Fig. 1 further includes an electric machine 19 which is configured to drive the compressor 16 of the turbocharger 17 to assist the turbine 17 of the same.

[0018] In Fig. The air supply device 13 has a common air supply module 20 for all fuel cells 11 connected in parallel, from which all fuel cells 11 can be supplied with air in parallel. The exhaust gas discharge device 14 has a common exhaust gas discharge module 21 for all fuel cells 11 connected in parallel, into which all fuel cells 11 connected in parallel feed their exhaust gas.

[0019] Fig. Figure 2 shows a modification of the fuel cell system 10. Fig. 1, wherein in the exemplary embodiment the Fig. 2. The supply air supply device 13 has an individual supply air supply module 22 for each of the parallel-connected fuel cells 11, and the exhaust gas discharge device 14 has an individual exhaust gas discharge module 23 for each of the parallel-connected fuel cells 11. Immediately adjacent supply air supply modules 22 and immediately adjacent exhaust gas discharge modules 23 are preferably detachably connected to one another, wherein the exemplary embodiment of Fig. 2 compared to the embodiment of the Fig. 1 has the advantage that the fuel cell system 10 is arbitrarily scalable with respect to the number of parallel-connected fuel cells 11 by adjusting the number of supply air modules 22 and the number of exhaust gas removal modules 23. With regard to all other details, the embodiment of Fig. 2 with the embodiment of the Fig. 1. This means that, to avoid unnecessary repetition, the same reference numbers are used for identical assemblies.

[0020] Fig. Figure 3 shows a modification of the fuel cell system 10. Fig. 1, wherein the embodiment of the Fig. 3 from the exemplary embodiment of the Fig. 1 differs only with regard to the arrangement of the electrical machine 19. While in Fig. 1 the electric machine 19 is arranged between the compressor 16 and the turbine 17 of the turbocharger 15 and is coupled to the shaft 18, is in Fig. 3 the electric machine 19 is positioned on the compressor side and coupled to the shaft 18.

[0021] The exemplary embodiment of the Fig. 4 differs from the embodiment of the Fig. 3 as well as the embodiment of the Fig. 2 from the exemplary embodiment of the Fig. 1 simply by the fact that the supply air device 13 and the exhaust gas discharge device 14 have an individual supply air module 22 and an individual exhaust gas discharge module 23, respectively, for each of the fuel cells connected in parallel. Therefore, for Fig. 3 and Fig. 4. For identical assemblies, the same reference numbers are used as in Fig. 1 and Fig. 2.

[0022] The exemplary embodiment of the Fig. 5 differs from the embodiment of the Fig. 1, Fig. 3 and the embodiment of the Fig. 6 of the exemplary embodiments of Fig. 2, Fig. 4 again only with regard to the positioning of the electric machine 19, wherein in the Fig. 5, Fig. 6 The electric machine 19 of the fuel cell system 10 is positioned on the turbine side next to the turbine 17 of the turbocharger 15 and is coupled to the shaft 18 via the turbine 17. Otherwise, the respective embodiments are identical, so that to avoid unnecessary repetition, the same reference numerals are used for identical assemblies.

[0023] Fig. Figure 7 shows a variation of the embodiment of the Fig. 3, in which the fuel cell system 10 has a further compressor 24, which is arranged to compress the supply air upstream of the compressor 16 of the turbocharger 15. The electric machine 19 serves to drive the further compressor 24; the compressor 16 of the turbocharger 15 is driven exclusively by the mechanical energy generated in the turbine 17. This differs from the embodiment of Fig. 8 in turn only by the fact that the air supply device 13 has an individual air supply module 22 for each of the parallel connected fuel cells 11 and the exhaust gas discharge device 14 has an individual exhaust gas discharge module 23 for each parallel connected fuel cell.

[0024] In the exemplary embodiment of the Fig. In addition to the turbocharger 15, the fuel cell system 10 has a further turbocharger 25, which in turn has a further compressor 24 and a further turbine 26. The further turbine 26 serves to expand the hydrogen gas supplied by the hydrogen supply unit 12 upstream of the fuel cells 11, whereby the mechanical energy gained in the further turbine 26 is used to drive the further compressor 24. The exemplary embodiment of Fig. 9 does without an electric machine 19; the energy to drive the compressor 16 is provided by the expansion of the exhaust gas in the area of ​​the turbine 17, and the mechanical energy to drive the further compressor 24 is provided by the expansion of hydrogen gas in the area of ​​the further turbine 26.

[0025] The exemplary embodiment of the Fig. 10 differs from the embodiment of the Fig. 9 in turn by the individual supply air modules 22 and individual exhaust gas removal modules 23.

[0026] The examples of implementation of Fig. 11 and Fig. 12, like the exemplary embodiments of the Fig. 9 and Fig. 10 via the further compressor 24 and a further turbine 26, however, the further turbine 24 and the further compressor 24 not as in Fig. 9 and Fig. 10 shown are not coupled via a further wave 27, rather, in Fig. 11 and Fig. 12 is coupled to the further compressor 24, the electric machine 19, and to the further turbine 26, a generator 28. In the exemplary embodiments of the Fig. 11 and Fig. 12 accordingly drives the further turbine 26, which serves to expand the hydrogen gas 12 upstream of the fuel cells 11, the generator 28 to generate electrical energy, which is provided by the generator 28 to the electric machine 19 to drive the further compressor 24. The exemplary embodiments of the Fig. 11 and Fig. 12 of these have, in contrast to the exemplary embodiments of the Fig. 9 and Fig. 10 about the advantage that the operation of the additional compressor 24 can be controlled via a corresponding control of the electric machine 19.

[0027] The examples of implementation of Fig. 11 and Fig. 12 differ from each other exclusively with regard to the design of the supply air device 13 and the exhaust gas discharge device 14, wherein in Fig. 11 as well as in Fig. 1, Fig. 3, Fig. 5, Fig. 7 and Fig. 9 the supply air supply device 13 for all parallel-connected fuel cells 11 has a common supply air supply module 20 and the exhaust gas discharge device 14 for all parallel-connected fuel cells 11 has a common exhaust gas discharge module 21, whereas in Fig. 12 as well as in Fig. 2, Fig. 4, Fig. 6, Fig. 8 and Fig. 10 the supply air supply device 13 for each of the parallel connected fuel cells 11 has an individual supply air supply module 22 and the exhaust gas discharge device 14 for each of the parallel connected fuel cells 11 has an individual exhaust gas discharge module 23.

[0028] The invention presented here allows for the efficient operation of parallel-connected fuel cells 11 with a simple design of a fuel cell system 10. Reference symbol list 10 Fuel cell systems 11 Fuel cell 12 Hydrogen supply facility 13 Supply air supply device 14 Exhaust gas discharge device 15 turbochargers 16 compressors 17 Turbine 18 wave 19 electric machine 20 Supply air supply module 21 Exhaust gas removal module 22 Supply air supply module 23 Exhaust gas removal module 24 additional compressors 25 more turbochargers 26 more turbines 27 more waves 28 Generator QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2018 112 454 A1

[0002] DE 10 2018 112 451 A1

[0003]

Claims

[1] Fuel cell system (10), with several fuel cells connected in parallel (11), with a hydrogen supply unit (12) which is set up to supply the fuel cells (11) with hydrogen, with an air supply device (13) which is configured to supply the fuel cells (11) with air, with an exhaust gas discharge device (14) which is designed to discharge exhaust gas from the fuel cells (11), with a turbocharger (15) comprising a compressor (16) and a turbine (17), wherein the compressor (16) is configured to compress supply air for the fuel cells (11) upstream of the supply air supply device (13), and wherein the turbine (17) is configured to expand exhaust gas from the fuel cells (11) downstream of the exhaust gas discharge device (14) and to use the energy obtained thereby to drive the compressor (16), with an electric machine (19) and / or a further turbine (26), wherein the electric machine (19) and / or the further turbine (26) is configured to drive the compressor (16) of the turbocharger (15) to assist the turbine (17) of the same or a further compressor (24). [2] Fuel cell system (10) according to claim 1, characterized by , that the multiple fuel cells (11) are connected in parallel with respect to the supply air, exhaust gas removal and hydrogen supply. [3] Fuel cell system (10) according to claim 1 or 2, characterized by , that the supply air supply device (13) for all parallel connected fuel cells (11) has a common supply air supply module (20), and that the exhaust gas discharge device (14) for all parallel connected fuel cells (11) has a common exhaust gas discharge module (21). [4] Fuel cell system (10) according to claim 1 or 2, characterized by, that the supply air supply device (13) has an individual supply air supply module (22) for each of the parallel connected fuel cells (11) and that the exhaust gas discharge device (14) has an individual exhaust gas discharge module (23) for each of the parallel connected fuel cells (11). [5] Fuel cell system (10) according to any one of claims 1 to 4, characterized by , that the compressor (16) of the turbocharger (15) and the turbine (17) thereof are coupled via a shaft (18), and that the electric machine (19) is coupled either on the side of the compressor (16) or on the side of the turbine (17) or between the compressor (16) of the turbocharger (15) and the turbine (17) thereof with this shaft (18). [6] Fuel cell system (10) according to any one of claims 1 to 4, characterized by, that the compressor (16) of the turbocharger (15) and the turbine (17) thereof are coupled via a shaft (18), and that the electric machine (19) and / or the further turbine (26) is coupled to the further compressor (24). [7] Fuel cell system (10) according to any one of claims 1 to 6, characterized by , that the further turbine (26) and the further compressor (24) are coupled via a further shaft (27). [8] Fuel cell system (10) according to any one of claims 1 to 7, characterized by , that the further turbine (26) drives a generator (28) which drives the electric machine (19).

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