Volute for a flow machine for a fuel cell system of a vehicle, in particular a utility vehicle, flow machine, fuel cell system, and vehicle

Abstract

The invention relates to a volute (100) for a flow machine (210) for a fuel cell system (205) of a vehicle (200a), in particular a utility vehicle (200b), wherein the volute (100) has: a flow inlet (110) for supplying the volute (100) with an air flow (105) which comprises fluid constituents (106); and a helical flow body (120) for guiding the air flow (105); wherein the flow body (120) has an outlet opening (125) for discharging fluid constituents (106), which are separated from the air flow (105) within the flow body (120), out of the flow body (120).

Description

[0001] Volute for a turbomachine for a fuel cell system of a vehicle, in particular commercial vehicle, turbomachine, fuel cell system, vehicle

[0002] The disclosure relates to a volute for a turbomachine for a fuel cell system of a vehicle, in particular a commercial vehicle, wherein the volute has: a flow inlet for subjecting the volute to an air flow comprising fluid components; and a spiral-shaped flow body for directing the air flow. The disclosure also relates to a turbomachine for a fuel cell system of a vehicle, in particular a commercial vehicle, comprising a volute, a fuel cell system comprising a turbomachine and a fuel cell stack operatively connectable to the turbomachine, and a vehicle, in particular a commercial vehicle, comprising a fuel cell system.

[0003] Turbomachines, including such volutes and fuel cell systems, are known in the art. Such a turbomachine typically comprises a bladed wheel or rotor. A spiral casing, also known as a volute, is arranged around the bladed wheel. Air flows through the volute, and the air's velocity is varied depending on the application as it passes through the volute until it exits the volute.

[0004] In fuel cell systems, a compressor is used to draw in air, compress it, and feed it to a cathode-side fuel cell inlet of a fuel cell to carry out the fuel cell reaction. The compressed mixture of substances passes through the stack(s) or fuel cell stack of the fuel cell. The mixture of substances remaining in the fuel cell stack after the reaction exits as a fluid stream on the cathode side from a cathode-side fuel cell outlet of the fuel cell stack. The fluid stream, also referred to as the air stream, can also contain liquid components, for example in the form of water droplets. This fluid stream is usually still at an excess pressure compared to the ambient pressure and is therefore used in most fuel cell systems to drive an expander shaft of an expander or a turbine.In the expander, the air flow exiting the outlet side can be expanded to ambient pressure, and the energy delivered to the expander shaft is usually converted into electrical energy if the expander is connected to a generator, and / or drives all or part of the compressor if the compressor and the expander have the same shaft.

[0005] DE 20 2022 103 117 U1 discloses a housing for receiving a rotor with compressor wheel and shaft, in particular a housing of a charger for an internal combustion engine or a fuel cell.

[0006] DE 10 2020 202 126 A1 discloses a gas supply device with at least one compressor impeller rotatable in a compressor volute, which is connected by a shaft in a rotationally fixed manner to a turbine impeller rotatable in a turbine volute, and with a bearing arrangement for the shaft.

[0007] One technological challenge is the handling of water and / or liquid components in the turbomachine, particularly in the flow body of a fuel cell turbocompressor. Typically, the air flow exiting the fuel cell stack on the cathode side has a comparatively high humidity of approximately 100%.

[0008] Fluid components such as drops and / or a liquid film on the expander's impeller can lead to erosion and / or corrosion of the impeller, which can ultimately affect and / or damage the turbomachine. Therefore, any fluid components must be removed, especially in the immediate vicinity of the impeller.

[0009] It is known from the prior art to provide a separate liquid filter or separator to separate liquid components from an air stream flowing in the flow body. The object of the disclosure is to enrich the prior art and improve aspects of the prior art. In particular, the object is to provide a liquid separator that is effective in terms of installation space and cost.

[0010] This object is achieved by a turbomachine according to claim 1 and the subject matter according to the further independent claims. The subclaims specify further developments of the invention.

[0011] According to one aspect of the invention, a volute for a turbomachine for a fuel cell system of a vehicle, in particular a commercial vehicle, is provided, wherein the volute comprises: a flow inlet for subjecting the volute to an air flow comprising fluid components; and a spiral-shaped flow body for guiding the air flow; wherein the flow body has an outlet opening for discharging fluid components separated from the air flow within the flow body from the flow body.

[0012] The volute has the flow inlet. The volute or its flow body can be exposed to the air flow via the flow inlet, in particular the air flow exiting the outlet side of a cathode of a fuel cell stack. The flow body is designed to receive the air flow. The air flow can pass through the volute according to the geometry of the flow body.

[0013] It was discovered that it is possible to design the volute in such a way that a liquid separator is functionally integrated. This utilizes the deflection of the air flow in the volute caused by the spiral shape of the flow body. By deflecting the air flow containing the fluid components, a centrifugal force can act on the fluid components, thus separating them from the air flow. The fluid components can precipitate as droplets and / or a film on a surface of the flow body and thus be separated from the air flow. The spiral housing has the discharge opening through which the fluid components can be discharged.

[0014] The volute thus enables reliable separation of fluid components from the airflow. By utilizing the separation of fluid components from the airflow caused by the deflection, an additional separator and / or filter is eliminated. This saves space and costs. Furthermore, a pressure drop caused by a filter, which could impair efficiency, can be avoided.

[0015] Optionally, the turbomachine includes a turbine. A turbine is a rotating turbomachine that causes a shaft to rotate upon expanding the airflow, thus converting energy from the airflow into rotational energy of the shaft. It was recognized that such an expander could be a primary application for the volute, since such an expander is typically located on the cathode side downstream of a fuel cell stack and is therefore typically exposed to an airflow with a comparatively high moisture content.

[0016] Optionally, the flow body has a diameter, and the diameter decreases downstream. The diameter can define the cross-section of the flow body, i.e., an extension of the flow body perpendicular to the flow direction or circumferential direction. The downstream decrease in the diameter makes it possible to provide a constant air mass flow in the circumferential direction and can thus enable uniform separation of the fluid components from the air flow. The flow body is not limited to a circular cross-section. The flow body can also have a different cross-section, for example, angular, in particular square, oval, and / or elliptical, whose cross-sectional area decreases downstream.

[0017] Optionally, the volute defines an axis; the flow body is arranged wound around the axis; and the discharge opening is located on a radially outer annular section of the flow body relative to the axis. It was recognized that the fluid components are deflected in the radially outer direction by the movement of the air flow and separated there. Arranging the discharge opening in the radially outer annular section can therefore promote the discharge of the fluid components.

[0018] Optionally, the flow body has a plurality of dispensing openings arranged sequentially in the flow direction. This makes it possible to dispense liquid at multiple locations on the flow body. In particular, it is possible to separate fluid components with a decreasing typical size in the flow direction or circumferential direction.

[0019] Optionally, the volute has an air return for reclaiming a portion of the air flow directed into the dispensing opening. This prevents comparatively high pressure and / or air buildup downstream of the dispensing openings, for example, in a possible collection chamber and / or in an area of ​​the dispensing opening, which can be detrimental to the separation and / or dispensing of the fluid components.

[0020] Optionally, the volute has a separation structure arranged in the flow body for separating fluid components from the air flow and for guiding the fluid components to the discharge opening. It has been recognized that it is possible to configure a surface of the flow body to guide the fluid components toward the discharge opening. For this purpose, the flow body has the separation structure. The separation structure can comprise, for example, channels, recesses, grooves, and / or other fluid guiding elements. The separation structure can provide forced guidance from the radial inside to the outside toward the discharge opening. The separation structure can be configured to absorb and drain a liquid film.

[0021] Optionally, the volute has an annular channel arranged at the flow inlet. The annular channel allows for the collection of liquid from a piping between the flow inlet and the fuel cell or fuel cell stack, thus enabling a preliminary separation of fluid components and air. The annular channel can be arranged obliquely relative to the circumferential direction and / or provide a guide for the liquid separated in the annular channel into a collection container and / or for drainage.

[0022] Optionally, the volute features a valve for controlling the discharge of fluid components from the discharge opening. The valve can be used to control the separation of fluid components.

[0023] Optionally, the volute has a diverter assembly arranged outside the flow body for diverting fluid components discharged from the discharge opening. The diverter assembly can, for example, be a channel arranged between the discharge opening and a collecting container, through which fluid components can be discharged from the flow body via the discharge opening and the diverter assembly into the collecting container.

[0024] Optionally, the dispensing opening is arranged in the assembled state such that the fluid components are guided to the dispensing opening and / or dispensed from the dispensing opening by gravity. This can assist the dispensing of the fluid components. The fluid components can be guided to the dispensing opening and / or dispensed from the dispensing opening by gravity if the dispensing openings are arranged in a lower region of the flow body or volute in the assembled state.

[0025] According to one aspect of the disclosure, a turbomachine for a fuel cell system of a vehicle, in particular a commercial vehicle, is provided, comprising a volute as described above. The turbomachine or the volute of the turbomachine can have one or more of the features of the volute described above as optional and / or advantageous in order to achieve an associated technical effect.

[0026] According to one aspect of the disclosure, a fuel cell system is provided, comprising a turbomachine as described above and a fuel cell stack operatively connected to the turbomachine. The fuel cell system, the turbomachine, or the volute of the turbomachine can have one or more of the features of the volute described above as optional and / or advantageous in order to achieve an associated technical effect.

[0027] According to one aspect of the disclosure, a vehicle, in particular a commercial vehicle, comprising a fuel cell system as described above is provided. The vehicle, in particular a commercial vehicle, the fuel cell system, the turbomachine, or the volute of the turbomachine, can have one or more of the features of the volute described above as optional and / or advantageous in order to achieve an associated technical effect.

[0028] Further features of the disclosure as well as its technical effects emerge from the figures and the description of the embodiments shown in the figures.

[0029] Fig. 1 is a schematic representation of a vehicle, in particular a commercial vehicle, according to an embodiment of the invention; and Fig. 2 is a schematic representation of a volute according to an embodiment of the invention.

[0030] Figure 1 shows a schematic representation of a vehicle 200a, in particular commercial vehicle 200b, according to an embodiment of the invention.

[0031] The vehicle 200a, in particular the commercial vehicle 200b, is referred to below as the vehicle 200a, 200b. The vehicle 200a, 200b is, for example, a land vehicle, in particular a towing vehicle and / or a trailer vehicle of a multi-unit vehicle, a single-unit vehicle, and / or a bus.

[0032] The vehicle 200a, 200b has a fuel cell system 205, an energy storage device 260, and an electric drive 250. The fuel cell system 205 is configured to provide electrical energy 65 to the energy storage device 260. The energy storage device 260 is, for example, a rechargeable energy storage device 260 and serves as a buffer battery for buffering electrical energy 65. The energy storage device 260 is connected to the electric drive 250 to supply the electric drive 250 with electrical energy 65 so that the electric drive 250 can drive the vehicle 200a, 200b. In addition, the fuel cell system 205 is connected to the electric drive 250 for the direct provision of electrical energy 65.The electric drive 250 can be configured for regenerative braking NB in ​​order to provide electrical energy 65 to the energy storage device 260 when the vehicle 200a, 200b is decelerated.

[0033] The fuel cell system 205 comprises a compressor 280, a fuel cell stack 206, and a turbomachine 210 configured as an expander 270, or turbine 215. As schematically indicated in Figure 1, the compressor 280 is configured to supply an air supply 240 to the cathode side of the fuel cell stack 206. For this purpose, the compressor 280 is configured to be supplied with electrical energy 65 in order to draw in air supply 239, compress it, and supply it to the fuel cell stack 206 as air supply 240. The expander 270 is configured to be supplied with an exhaust gas flow 245 from the fuel cell stack 206 in order to convert energy from the exhaust gas flow 245 into electrical energy 65. Alternatively or additionally, the energy of the expander 270 is converted directly into mechanical energy and used directly to drive (torque support) the drive shaft of the compressor 280.The exhaust gas stream 245 is an air stream 105 comprising fluid components 106. The expander 270 or the turbomachine 210 has a volute 100. The air stream 105 passes through the volute 100. After the exhaust gas stream 245 or air stream 105 has been expanded by the expander 270, expanded exhaust air 246 exits the expander 270.

[0034] An embodiment of the volute 100 of the turbomachine 210, embodied as an expander 270 in Figure 1, is described with reference to Figure 2. Figure 2 shows a schematic representation of a volute 100 according to an embodiment of the invention. The volute 100 according to Figure 2 is a volute 100 for a turbomachine 210 for a fuel cell system 205 of a vehicle 200a, 200b. Such a turbomachine 210 and such a vehicle 200a, 200b are described with reference to Figure 1. Figure 2 is described with reference to Figure 1.

[0035] The volute 100 according to Figure 2 has a flow inlet 110 for supplying the volute 100 with an air flow 105 comprising fluid components 106. The flow inlet 110 can be connected directly to a cathode-side outlet of a fuel cell stack 206 in order to be supplied with the air flow 105. In Figure 2, the direction of movement of the air flow 105 or its gaseous components is illustrated by double arrows with a solid line. The direction of movement of the fluid components 106 is illustrated by double arrows with a dashed line.

[0036] The volute 100 has an annular channel 115 arranged at the flow inlet 110. The annular channel 115 can collect and separate fluid components 106 that accrue or precipitate, in particular, in the connection between the fuel cell stack 206 and the flow inlet 110.

[0037] The volute 100 has a spiral-shaped flow body 120 for guiding the air flow 105. The flow body 120 has a circumferential direction that corresponds to a flow direction S of the air flow 105. The volute 100 or the flow body defines an axis A. In the illustration according to Figure 2, the axis A points into the image plane, as schematically indicated by a cross. The flow body 120 is arranged wound around the axis A. The flow body 120 is thus helical and has a curvature. The curvature of the flow body 120 decreases in the flow direction S, or the flow body 120 has a radius that decreases in the flow direction S.The curvature of the volute 100 or the flow body 120 can be increased in the region of the flow inlet 110 (not shown) in order to achieve an increased deflection of the air flow 105 and thus an increased separation of the fluid components 106 from the air flow 105.

[0038] Perpendicular to the flow direction S, the flow body 120 has a diameter D. The diameter D defines a cross-section of the flow body 120 through which the air flow 105 can flow. The diameter D or the area of ​​the cross-section decreases downstream.

[0039] The flow body 120 has a plurality of discharge openings 125, each for discharging fluid components 106 separated from the air stream 105 within the flow body 120. In another embodiment, the flow body 120 may have one discharge opening 125 or any number of discharge openings 125 (not shown). Each of the discharge openings 125 is configured to enable discharge of fluid components 106 separated and / or precipitated in the flow body 120 from the flow body 120.

[0040] The dispensing openings 125 are arranged on a radially outer annular section 121 of the flow body 120 relative to the axis A. In the assembled state, the dispensing openings 125 are arranged such that the fluid components 106 are guided to the dispensing openings 125 and / or dispensed from the dispensing openings 125 by gravity. The fluid components 106 can move along the annular section 121 to the dispensing openings 125 due to gravity and / or the air flow 105.

[0041] The discharge openings 125 are arranged sequentially in the flow direction S. Thus, the flow body 120 has discharge openings 125 arranged downstream of one another in the flow direction S. The discharge openings 125 can have the same and / or different sizes.

[0042] The volute 100 has a separation structure 122 arranged in the flow body 120, as schematically indicated by a line between the flow inlet 110 and the discharge openings 125. The separation structure 122 is configured to separate fluid components 106 from the air flow 105 and guide them to the discharge opening 125. The separation structure 122 is arranged in the radially outer ring section 121 and / or around the radially outer ring section 121. The separation structure 122 comprises, for example, a channel, a groove, and / or a channel in which the fluid components 106 can be collected and discharged.

[0043] The volute 100 has a discharge arrangement 150 arranged outside the flow body 120 for discharging fluid components 106 discharged from the discharge opening 125. In another embodiment, the volute 100 or the discharge opening 125 can be fluidically connected to a discharge arrangement 150. As shown in Figure 2, the discharge arrangement 150 has a discharge element (not indicated) for each discharge opening 125. Fluid components 106 can be discharged from one of the discharge openings 125 into one of the discharge elements of the discharge arrangement 150. The discharge arrangement 150 can comprise a plurality of pipes, each forming a discharge element and arranged between the flow body 120 and a collecting container 155. The discharge arrangement 150 thus comprises a channel branched according to the number of discharge openings 125.The deflection arrangement 150 has a curvature that approximately matches the curvature of the flow body 120 in the region of the discharge openings 125. This allows for sufficient separation while using a comparatively small amount of installation space.

[0044] The volute 100 is operatively connected to the collecting container 155 or reservoir and / or intermediate storage device. The diverter arrangements 150 are configured to direct the fluid components 106 from the flow body 120 into the collecting container 155. An air flow portion 107 comprising fluid components 106 can branch off from the air flow 105. The air flow portion 107 is thus directed out of the flow body 120 and via the diverter arrangement 150 into the collecting container 155. The diverter arrangement 150 and the collecting container 155 are integrally formed in the example.

[0045] The volute 100 has an air return 130 for reclaiming the air flow portion 107 directed into the discharge opening 125. The air flow portion 107 is thus redirected into the flow body 120 via the air return 130 and can thus continue to flow through the flow body 120. The air return 130 can comprise piping arranged between the collection container 155 and the flow body 120. In another embodiment (not shown), the volute 100 does not have an air return 130. An air return 130 may be dispensable.

[0046] The volute 100 has a valve 140 for controlling the discharge of fluid components 106 from the discharge opening 125. In the schematic of Figure 2, the valve 140 is arranged in the collection container 155, but can also be arranged at the discharge openings 125 (not shown). The valve 140 can selectively enable and / or prevent the discharge of fluid components 106 from the discharge openings 125. When the valve 140 is closed, the air flow portion 107 flowing through the diverter assembly 150 and the collection container 155 is eliminated.

[0047] Reference symbol (part of the description)

[0048] 65 electrical energy

[0049] 100 Volute

[0050] 105 Airflow

[0051] 106 fluid components

[0052] 107 air flow part

[0053] 110 Flow inlet

[0054] 115 Ring Canal

[0055] 120 flow bodies

[0056] 121 ring section

[0057] 122 Separation structure

[0058] 125 Dispensing opening

[0059] 130 Air return

[0060] 140 valve

[0061] 150 discharge arrangement

[0062] 155 collection containers

[0063] 200a vehicle

[0064] 200b commercial vehicle

[0065] 205 Fuel cell system

[0066] 206 fuel cell stacks

[0067] 210 Turbomachine

[0068] 215 Turbine

[0069] 220 fuel cell

[0070] 239 Supply air

[0071] 240 supply air flow

[0072] 245 exhaust gas flow

[0073] 246 exhaust air

[0074] 250 electric drive of the vehicle

[0075] 260 Energy storage device

[0076] 270 expanders

[0077] 280 compressors

[0078] A Axis D Diameter

[0079] NB regenerative braking

[0080] S Flow direction

Claims

Patent claims 1. Volute (100) for a turbomachine (210) for a fuel cell system (205) of a vehicle (200a), in particular a commercial vehicle (200b), wherein the volute (100) comprises: - a flow inlet (110) for supplying the volute (100) with an air flow (105) comprising fluid components (106); and - a spiral-shaped flow body (120) for guiding the air flow (105); wherein - the flow body (120) has an outlet opening (125) for discharging fluid components (106) separated from the air flow (105) within the flow body (120) from the flow body (120).

2. Volute (100) according to claim 1, wherein the turbomachine (210) comprises a turbine (215).

3. Volute (100) according to claim 1 or 2, wherein the flow body (120) has a diameter (D), and the diameter (D) decreases downstream.

4. Volute (100) according to one of the preceding claims, wherein - the volute (100) defines an axis (A); - the flow body (120) is arranged wound around the axis (A); and - the discharge opening (125) is arranged on a radially outer ring section (121) of the flow body (120) with respect to the axis (A).

5. Volute (100) according to one of the preceding claims, wherein the flow body (120) has a plurality of discharge openings (125) arranged sequentially in the flow direction (S).

6. Volute (100) according to one of the preceding claims, wherein the volute (100) has an air return (130) for re-absorbing a portion of the air flow (107) directed into the dispensing opening (125).

7. Volute (100) according to one of the preceding claims, wherein the volute (100) has a separation structure (122) arranged in the flow body (120) for separating of fluid components (106) from the air stream (105) and for guiding the fluid components (106) to the dispensing opening (125).

8. Volute (100) according to one of the preceding claims, wherein the volute (100) has an annular channel (115) arranged at the flow inlet (110).

9. Volute (100) according to one of the preceding claims, wherein the volute (100) has a valve (140) for controlling the dispensing of fluid components (106) from the dispensing opening (125).

10. Volute (100) according to one of the preceding claims, wherein the volute (100) has a discharge arrangement (150) arranged outside the flow body (120) for discharging fluid components (106) discharged from the discharge opening (125).

11. Volute (100) according to one of the preceding claims, wherein the dispensing opening (125) is arranged in the assembled state such that the fluid components (106) are guided to the dispensing opening (125) and / or dispensed from the dispensing opening (125) by gravity.

12. Turbomachine (210) for a fuel cell system (220) of a vehicle (200a), in particular a commercial vehicle (200b), comprising a volute (100) according to one of the preceding claims.

13. A fuel cell system (205) comprising a turbomachine (210) according to claim 12 and a fuel cell stack (206) that can be brought into operative connection with the turbomachine (210).

14. Vehicle (200a), in particular commercial vehicle (200b), comprising a fuel cell system (205) according to claim 13.

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