Gas supply device for fuel cell

Abstract

The invention relates to a gas supply device having a suction line for a gas to be sucked in and a pressure line for conveying the sucked gas, a compressor wheel being rotatably mounted between the suction line and the pressure line by means of a shaft which is mounted by means of at least one bearing, a drive unit being provided for driving the shaft, the invention relates to a gas supply device, in which a space, which can be supplied with gas via an opening, is formed in order to control the temperature of the space, means are provided for suctioning gas from the surroundings via the opening, the compressor wheel being arranged on one end of the shaft, and the other compressor wheel of the turbine being arranged on the other end of the shaft, the other compressor wheel is arranged in a turbine volute of the turbine for driving the shaft, the turbine input end of the turbine volute is connected to the pressure line, and the gas sucked in through the suction line can be supplied to the consumer downstream of the turbine wheel via the turbine output end of the turbine volute, the means for suction comprising a cooling device, the cooling device is used for cooling sucked gas.

Description

Technical Field

[0001] The invention relates to a gas supply device for a fuel cell. Background Art

[0002] Gas supply devices are already known, for example from documents CN 218439809U and CN 218439832U, which are arranged for cooling drive units, in which however the cooling gas directed to the suction side or the turbine reduces the delivery performance of the gas supply device due to its relatively high temperature. Summary of the invention

[0003] The invention provides a gas supply device having a suction line for gas to be sucked in and a pressure line for conveying the sucked in gas, wherein a compressor impeller is arranged between the suction line and the pressure line in a rotatable manner via a shaft, wherein the shaft is supported by at least one bearing, and wherein a drive unit, in particular an electric motor drive unit, is provided for driving the shaft, wherein a space to which gas can be supplied via an opening is formed in the gas supply device for temperature control of the space, wherein a device for sucking in gas from the surroundings via the opening is provided, wherein the compressor impeller is arranged at one end of the shaft and another compressor impeller of a turbine is arranged at the other end of the shaft, wherein the other compressor impeller is provided for driving the shaft by being arranged in a turbine volute of the turbine, wherein a turbine input end of the turbine volute is connected to the pressure line and gas sucked in via the suction line can be supplied to a consumer downstream of the turbine impeller via a turbine output end of the turbine volute, wherein the device for suction comprises a cooling device, which is provided for cooling the sucked in gas. In contrast, the gas supply device according to the invention as a two-stage compressor has the advantage of improved delivery performance. Here, the gas is also used at least indirectly to supply the space to be cooled or the components to be cooled of the gas supply device. The delivery performance and durability of the gas supply device can therefore also be improved, for example by arranging the drive unit or the bearing in the space so that the drive unit or the bearing can be cooled accordingly. Here, a device for sucking gas from the surrounding environment is advantageously provided in order to supply the space to be cooled with gas or cooling air. In addition, the device comprises a cooling device in order to improve the delivery performance of the two-stage compressor.

[0004] Advantageous embodiments and improvements of the gas supply device are given below.

[0005] It is particularly advantageous if the cooling air drawn in for the space is cleaned by means of a preceding air filter before reaching the space in order to protect the air from harmful environmental influences.

[0006] According to one embodiment, the drive unit and / or at least one bearing is arranged in a space that can be supplied with gas.

[0007] According to one development, the means for suction comprises a Venturi assembly which is provided for suctioning gas in the space which is available for gas, so that gas can flow into the space via the opening.

[0008] According to one development, the Venturi assembly is connected to the pressure side of the compressor wheel.

[0009] According to one development, the Venturi assembly is provided to convey gas from the pressure side and gas sucked in from the gas-available space to the intake line or the turbine inlet or to the surroundings of the gas supply device.

[0010] According to one development, the cooling device is arranged downstream of the Venturi assembly in order to cool the gas before it enters the intake line or the turbine inlet.

[0011] According to one development, a gas path branches off from the pressure side of the compressor wheel, which gas path is connected to the Venturi assembly, wherein the gas path comprises a return line connected to the suction line downstream, and wherein the cooling device is arranged in the return line.

[0012] According to one development, the Venturi assembly is arranged in the pressure line, wherein the pressure line opens into the turbine inlet downstream of the Venturi assembly, wherein the cooling device is arranged between the Venturi assembly and the turbine inlet.

[0013] According to one embodiment, a filter for cleaning the gas flowing into the space is arranged upstream of the opening or in the opening.

[0014] According to one embodiment, the shaft is designed as a rotor and the drive unit is designed as a stator for electromagnetically driving the rotor.

[0015] According to one embodiment, the consumer is a fuel cell stack.

[0016] Furthermore, the invention provides a fuel cell system having at least one fuel cell stack and a gas supply device according to the invention for supplying the cathode side of the fuel cell with air or oxygen. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Exemplary embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description.

[0018] Figure 1 showing a gas supply device, and

[0019] Figure 2 Another gas supply arrangement is shown. DETAILED DESCRIPTION

[0020] Figure 1 A gas supply device 20 is shown, which can suck in gas during operation via a suction line 18 or a related suction line connection not shown in detail, and deliver the sucked gas to a gas consumer 24 via a pressure line 22 or a turbine output 37. Here, a compressor impeller 26 is arranged between the suction line and the pressure line, wherein the side of the compressor impeller 26 facing the suction line forms a suction area 38, from which gas or air is sucked in or compressed. Here, the compressor impeller 26 is fixedly connected to the shaft 28, and the rotational movement of the shaft also puts the compressor impeller into rotational movement. The shaft is supported by two bearings 13, and a drive unit 12, in particular an electric motor drive unit, is provided for driving the shaft 28. In the case of a configuration as an electric motor drive unit, the drive unit forms an electrically controllable stator, which can put the shaft, which is configured as a rotor in this case, into rotational movement by means of magnetic force.

[0021] The drive unit and the two bearings are arranged in a space 16 which can be supplied with air via an opening 36 .

[0022] The venturi assembly 10 is provided for sucking in cooling air 11 for cooling the drive unit or the bearing. The venturi assembly sucks in air from the space 16 on the side opposite to the opening 36, so that fresh cooling air 11 can flow in via the opening 36 and cool the drive unit 12, in particular the stator or the bearing 13 via the cooling air path 17. The venturi assembly generates the negative pressure required for this purpose in its narrowing region by means of the gas flowing through it. Here, the venturi assembly is arranged in a pressure line 22, which is fed with gas from the pressure side 40 of the compressor impeller 26. Therefore, the gas that has been compressed by the gas supply device and is intended for the consumer device 24 is first used indirectly in the gas supply device for supplying the space 16, in that a negative pressure is provided by means of the venturi assembly, which can be used to suck in cooling air 11 from the surrounding environment. The described suction of maximum cold air 11, in particular from the surrounding environment, is used to optimize the performance of the electric air compressor or the gas supply device. The cooling air is thus distributed in the interior space 16 of the compressor on different air paths 17, supplied to the areas and components to be cooled, and then discharged. Here, the gas is guided downstream of the Venturi assembly to the turbine inlet 35 of the turbine volute 41 of the turbine together with the gas sucked in from the space 16. The gas supply device 20 is a two-stage air compression device in which a compressor wheel 26 is arranged at one end of the shaft 28, and a further compressor wheel 34 in the turbine volute 41 is arranged at the other end, wherein the turbine wheel is provided for driving the shaft by means of gas supplied via the pressure line 22 at the turbine inlet 35 of the turbine volute 41. Downstream of the further compressor wheel 34, the gas is supplied to the consumer 24 via the turbine outlet 37 of the turbine volute 41.

[0023] The drive via the turbine wheel supplements the drive via the electric motor drive unit, so that by suitable actuation of the electric motor drive unit or by suitable switchable gas routing one drive mode or the other or both drive modes can be used selectively or in parallel.

[0024] The air filter 15 is arranged in the cooling air intake line 14 or cooling air intake connection upstream of the opening 36 of the gas supply device 20 so that the gas or cooling air 11 flowing into the chamber 16 is cleaned before reaching the chamber 16. Alternatively, the air filter can also be arranged directly in the opening.

[0025] A cooling device 19 is arranged in the pressure line 22 between the Venturi assembly 10 and the turbine inlet 35 , which serves to cool the gas flowing in the pressure line, including the gas sucked in from the space 16 , before reaching the turbine volute 41 .

[0026] The consumer 24 supplied with gas or air compressed by the gas supply device can be, in particular, a fuel cell stack, to which air or oxygen is supplied on its cathode side in this way. Thus, the fuel cell system can have at least one fuel cell stack and at least one such gas supply device in order to supply the cathode side of the fuel cells of the fuel cell stack with air or oxygen. In this case, the gas or exhaust gas of the fuel cell stack that is not consumed by the fuel cell stack can be fed back to the gas supply device in order to drive a further compressor wheel 34 of the gas supply device and thereby at least contribute to the compression or intake of the required gas by the gas supply device.

[0027] Figure 2 A gas supply device 200 is shown, wherein Figure 1 The same or similar components of the gas supply device 20 are provided with the same reference numerals and will not be described again. Figure 1 Unlike the components of the venturi assembly 10, the venturi assembly 10 is not arranged in the pressure line 22, but is connected to a separate gas path 30, which branches off from the pressure side 40 of the compressor impeller 26 of the gas supply device 200. Therefore, the gas that has been compressed by the gas supply device and is actually destined for the consumer 24 is partially branched off in the gas supply device, so that this gas can be used indirectly for supplying the space 16 by providing a negative pressure, which can draw in cooling air from the surrounding environment with the help of the venturi assembly. Downstream of the venturi assembly, the branched gas is guided to the suction line 18 of the gas supply device via a return line 32 together with the gas sucked from the space. The cooling device 19 is also not located in the pressure line 22 here, but is located in the return line 32 between the venturi assembly 10 and the suction line 18, in order to cool the returned gas before it is sucked in again by the compressor impeller 26.

[0028] Alternatively, the return line 32 can also be used only to return the branched gas to the surroundings. In this case, the return line has an open end facing the surroundings in a manner not shown in detail and is not connected to the suction line 18 accordingly. In this case, the cooling device 19 is formed in a manner not shown in detail only by the open end of the return line configured and arranged in this way, via which the branched gas is discharged into the surroundings and is cooled thereby. In contrast to the previous embodiment, the direct discharge into the surroundings via the open end is not provided with an active cooling device, i.e., an electrically controllable cooling device, but only the open end itself constitutes a passive cooling device to a certain extent, so to speak, for the discharge of gas into the ambient air.

Claims

1. A gas supply device (20, 200) having a suction line (18) for gas to be inhaled and a pressure line (22) for conveying the inhaled gas, wherein: A compressor impeller (26) is arranged rotatably supported via a shaft (28) between the suction line (18) and the pressure line (22), wherein the shaft is supported via at least one bearing (13), and wherein a drive unit (12), in particular an electric drive unit, is provided for driving the shaft (28), wherein a space (16) is formed in the gas supply device (20) to which gas can be supplied via an opening (36) for temperature control of the space, wherein means (10, 19) are provided for sucking in gas from the surroundings via the opening (36), wherein the compressor impeller (26) is arranged at one end of the shaft (28), and the turbine (3 4, 41) is arranged at the other end of the shaft, wherein the other compressor impeller is configured to drive the shaft by being arranged in a turbine volute (41) of the turbine, wherein a turbine input end (35) of the turbine volute (41) is connected to the pressure line (22), and gas sucked in through the suction line (18) can be supplied to a consumer (24) via a turbine output end (37) of the turbine volute (41) downstream of the turbine impeller (34), characterized in that the device (10, 19) for suction includes a cooling device (19), which is configured to cool the sucked gas.

2. The gas supply device according to claim 1, characterized in that: The drive unit (12) and / or the at least one bearing (13) are arranged in a space (16) which can be supplied with air.

3. The gas supply device according to claim 1 or 2, characterized in that: The means (10, 19) for suction comprises a Venturi assembly (10) which is arranged for suctioning gas in the gas-available space (16) so that gas can flow into the space via the opening (36).

4. The gas supply device according to claim 3, characterized in that: The venturi assembly (10) is connected to the pressure side (40) of the compressor impeller (26).

5. The gas supply device according to claim 4, characterized in that: The venturi assembly is configured to convey gas from the pressure side (40) and gas sucked in from the gas supply space (16) to the suction line (18) or the turbine input (35), or to the surroundings of the gas supply device.

6. The gas supply device according to claim 5, characterized in that: The cooling device (19) is arranged downstream of the Venturi assembly (10) for cooling the gas before it enters the suction line (18) or the turbine input (35).

7. The gas supply device according to claim 5 or 6, characterized in that: A gas path (30) branches off from the pressure side (40) of the compressor impeller (26), the gas path being connected to the Venturi assembly (10), wherein the gas path (30) comprises a return line (32) downstream which is connected to the suction line (18), and wherein the cooling device (19) is arranged in the return line (32).

8. The gas supply device according to claim 5 or 6, characterized in that: The Venturi assembly (10) is arranged in the pressure line (22), wherein the pressure line leads to the turbine input (35) downstream of the Venturi assembly, wherein the cooling device (19) is arranged between the Venturi assembly (10) and the turbine input (35).

9. A gas supply device according to any one of the preceding claims, characterised in that A filter (15) for cleaning the gas flowing into the space (16) is arranged before the opening (36) or in the opening (36).

10. A gas supply device according to any one of the preceding claims, characterised in that The shaft (28) is designed as a rotor and the drive unit (12) is designed as a stator for electromagnetically driving the rotor.

11. A gas supply device according to any one of the preceding claims, characterised in that The consumer (24) is a fuel cell stack. 12 . A fuel cell system having at least one fuel cell stack and at least one gas supply device according to claim 1 for supplying the cathode side of the fuel cell with air or oxygen.

Images