FUEL CELL INJECTOR / EJECTOR

Abstract

Injector / ejector assembly (40) for a fuel cell, the assembly comprising the following: a body part (60) extending along a central longitudinal axis (A); a plurality of recirculation flow passages (62) formed by and extending through the body part (60), each of the plurality of recirculation flow passages (62) extending from a corresponding recirculation flow inlet (64) to a corresponding recirculation flow outlet (66); a motive current passage (68) formed by and extending through the body part (60); a plurality of tongue blades (70) enclosing at least part of the corresponding recirculation flow outlet (66) for each of the plurality of recirculation flow passages (62); wherein each of the plurality of tongue leaves (70) is attached to the body part (60) adjacent to an upstream end relative to a flow direction through the assembly; wherein the tongue blades (70) comprise six circumferentially spaced tongue blades (70) surrounding the body part (60); wherein the body part (60) has a base part with an outer circumferential surface (74) that separates each of the corresponding recirculation flow inlets (64) from the corresponding recirculation flow outlet (66) for each of the plurality of recirculation flow passages (62); and with a plurality of ribs extending from a rib body section which is attached relative to the body section, the plurality of ribs being arranged radially outward from a corresponding plurality of tongue blades.

Description

[0001] The subject matter of the disclosure relates to the technology of fuel cells and in particular to the combination of the return flow from a fuel cell stack with a fuel flow.

[0002] A fuel cell is a device that generates electricity through a chemical reaction. Every fuel cell has two electrodes, a positive and a negative one, called the cathode and anode, respectively. The reactions that generate electricity take place at the electrodes. Every fuel cell also has an electrolyte, which transports electrically charged particles from one electrode to the other, and a catalyst, which accelerates the reactions at the electrodes. Hydrogen is the primary fuel, but fuel cells also require oxygen. One advantage of fuel cells is that they generate electricity with very low environmental impact; that is, most of the hydrogen and oxygen used in electricity generation ultimately combine to form a harmless byproduct: water.

[0003] KR 10 2016 0 048 547 A describes a nozzle assembly and a vacuum ejector. The nozzle assembly of the vacuum ejector creates a vacuum in an intake port by expelling gas flowing in through an inlet port through an outlet port. The nozzle assembly comprises a nozzle and a valve body that opens and closes a suction passage.

[0004] DE 102 51 878 A1 describes a fuel circuit of a fuel cell system in which a fuel pump can be throttled when energy consumption is controlled / regulated, thereby ensuring a consistent fuel circulation flow rate during changes in the power output of the fuel cell. The fuel circuit comprises a fuel supply section, a fuel circulation section, a fuel pump, and an ejector.

[0005] DE 10 2021 207 648 A1 describes a jet pump and a fuel cell system with such a jet pump to provide increased efficiency. The jet pump comprises a drive nozzle with an outlet for at least one primary gas, wherein the outlet has an outlet cross-section in a plane perpendicular to an outlet direction of the drive gas, a mixing chamber for mixing the primary gas with a secondary gas, and a diffuser for decelerating the mixed gas.

[0006] KR 10 2016 0 013 420 A describes an ejector for a fuel cell vehicle that is capable of mixing hydrogen supplied by a fuel cell system through a hydrogen supply line with hydrogen circulated through a recirculation line in order to supply the mixed hydrogen to a fuel cell stack.

[0007] An injector / ejector assembly for a fuel cell is presented here. The assembly according to the invention comprises a body section extending along a central longitudinal axis. Recirculation flow passages are formed through and extend through the body section. Each of the recirculation flow passages extends from a corresponding recirculation flow inlet to a corresponding recirculation flow outlet. A motive flow passage is formed through and extends through the body section, and tongue blades enclose at least a portion of the corresponding recirculation flow outlet for each of the recirculation flow passages.

[0008] One embodiment provides that the recirculation flow passages are arranged circumferentially around the body part.

[0009] According to the invention, each of the tongue blades is attached to the body part near an upstream end of each of the tongue blades with respect to a flow direction through the assembly.

[0010] According to the invention, the body part has a base part with an outer circumferential surface that separates each of the corresponding recirculation flow inlets from the corresponding recirculation flow outlet for each of the recirculation flow passages.

[0011] According to the invention, the injector / ejector assembly comprises ribs extending from a rib body part that is attached relative to the body part. The ribs are arranged radially outwards from a corresponding tongue blade.

[0012] One embodiment provides that the tongue blades each taper from a base to a distal end.

[0013] One embodiment provides that at least part of the tractive current passage extends along the central longitudinal axis.

[0014] One embodiment provides that the driving current passage has an outlet at a distal end of the body part, which is located downstream with respect to the central longitudinal axis of the return current outlet.

[0015] One embodiment provides that part of the inlet to the motive flow passage lies transversely to the recirculation flow passages.

[0016] One embodiment provides that a proximal end of each of the tongue blades is fixed against movement relative to the body part.

[0017] According to the invention, the tongue leaves comprise six tongue leaves spaced apart in the circumferential direction, which surround the body part.

[0018] Here, a fuel cell system is presented as an application example of the injector / ejector assembly according to the invention. The system comprises at least one fuel cell with an anode inlet and an anode outlet. A hydrogen tank is in fluid communication with the anode inlet. An injector / ejector, which is an injector / ejector assembly according to the invention, is in fluid communication with the hydrogen tank, the anode inlet, and the anode outlet. The injector / ejector comprises a body part that extends along a central longitudinal axis. Recirculation flow passages are formed by and extend through this body part, with each recirculation flow passage extending from a corresponding recirculation flow inlet to a corresponding recirculation flow outlet.A driving flow passage is formed through and extends through the body part, and tongue blades enclose at least part of the corresponding recirculation flow outlet for each of the recirculation flow passages.

[0019] This document describes, as an application example, a method for operating a fuel cell system. The method involves directing fuel from a fuel source into a drive flow passage in a body part of an injection / injection assembly, the body part extending along a central longitudinal axis. A recirculation flow from an anode outlet on a fuel cell is directed into one of several recirculation flow passages extending through the body part. The recirculation flow and the fuel from the fuel source mix downstream of a recirculation flow outlet and a drive flow outlet. The tongue blades enclose at least a portion of the corresponding recirculation flow outlet for each of the recirculation flow passages.

[0020] Further features, advantages and details are included only as examples in the following detailed description, which refers to the figures in which they are depicted: In Fig. Figure 1 shows a schematic representation of a fuel cell system. Fig. Figure 2 shows a perspective front view of an injection / ejection device of the fuel cell system of Fig. 1. Fig. Figure 3 shows a perspective rear view of the injection / ejection device. Fig. 2. Fig. Figure 4 shows a front view of the injection / ejection device. Fig. 2. Fig. Figure 5 shows a front view of the injection / ejection device. Fig. 2. Fig. Figure 6 shows a perspective rear view of the injection / ejection device. Fig. 2 without slats. Fig. Figure 7 shows a perspective view of tongue blades that are connected to the injection / ejection device. Fig. 2 can be used. Fig. Figure 8 schematically shows a recirculation flow and a driving flow through the injector / ejector unit. Fig. 2. Fig. Figure 9 shows an example of a method for operating a fuel cell system from Fig. 1 with the injectors / ejectors disclosed herein. Fig. Figure 10 shows a perspective front view of another example of an injection / ejection device of the fuel cell system from Fig. 1. Fig. Figure 11 shows a perspective rear view of the injection / ejection device of Fig. 10. Fig. Figure 12 shows a perspective view of tongue blades connected to the injection / ejection device of the fuel cell system of Fig. 10 can be used. Fig. Figure 13 shows a perspective rear view of the injection / ejection device of the fuel cell system of Fig. 10 without slats. Fig. Figure 14 shows a perspective rear view of a rib body part with a multitude of ribs.

[0021] With reference to the figures, in which the same reference numerals denote the same parts in the different views, a fuel cell system 20 and a method 100 for operating or controlling the fuel cell system 20 are shown and described here.

[0022] Fig. Figure 1 shows an example of a fuel cell system 20. The fuel cell system 20 comprises a fuel cell stack 22 with an anode 24 and a cathode 26. Hydrogen gas is supplied from a fuel source 28, e.g., a hydrogen fuel cell source, to the anode 24 via an anode inlet line 30, and oxygen or air is supplied from a compressor 32 or another oxygen / air source to the cathode 26 via a cathode inlet line 34. An injector / ejector 40, comprising an injector or injector part and an ejector or ejector part, is located downstream of the fuel source 28 and is in fluid communication with the anode inlet line 30.

[0023] An anode exhaust line 42 extends from an outlet of the anode 24, and a cathode exhaust line 44 extends from an outlet of the cathode 26. The anode exhaust line 42 can carry unused hydrogen gas away from the anode 24, and the cathode exhaust line 44 can carry unused oxygen / air away from the cathode 26. Water and other liquids or gases from the fuel cell stack 22 can be discharged in one or both exhaust lines 42, 44. An anode exhaust valve 46 can be arranged in the anode exhaust line 42, with the portion of the anode exhaust line 42 downstream of the anode exhaust valve 46 being connected to the cathode exhaust line 44 and having an anode exhaust valve flow rate 50.

[0024] A return line 52 runs from a first end, which is connected to a section of the anode outlet line 42 upstream of the anode outlet valve 46, to a second end, which is connected to the ejector section of the injector / ejector 40. In this assembly, at least some of the unused hydrogen gas that enters the anode outlet line 42 from the anode 24 can be returned to the anode 24 via the return line 52.

[0025] The fuel cell system 20 also includes a control unit 54, which is electrically connected to various parts of the fuel cell system 20, such as the injector / ejector 40, the anode outlet valve 46 and the compressor 32, in order to carry out the procedure 100 described here.

[0026] The electronic control unit 54 can be implemented as one or more digital computers or host machines, each comprising one or more processors, read-only memory (ROM), random-access memory (RAM), electrically programmable read-only memory (EPROM), optical drives, magnetic drives, etc., a high-speed clock, analog-to-digital (A / D) circuits, digital-to-analog (D / A) circuits, input / output (I / O) circuits, I / O devices and communication interfaces, as well as signal conditioning and buffer electronics. The computer-readable memory can include a non-volatile / tangible medium involved in providing data or computer-readable instructions. The memory can be either non-volatile or volatile. Non-volatile media can include, for example, optical or magnetic disks and other persistent storage media.An example of volatile memory is dynamic random-access memory (DRAM), which can represent main memory. Other examples of memory include flexible disks, hard disks, magnetic tapes or other magnetic media, CD-ROMs, DVDs and / or other optical media, as well as other possible storage devices such as flash memory.

[0027] As in the Fig. As shown in Figures 2-5, the injector / ejector assembly 40 comprises a body part 60 extending along a central longitudinal axis A. A plurality of recirculation flow passages 62 extend through the body part 60 from a recirculation flow inlet 64 near a proximal end of the body part 60 to a recirculation flow outlet 66 near a distal end of the body part 60. Both the recirculation flow inlet and the recirculation flow outlets 64, 66 are defined around a circumference through the body part, with the cross-sectional area of ​​the recirculation flow outlets 66 being larger than the cross-sectional area of ​​the recirculation flow inlets 64.

[0028] The proximal end of the body part 60 comprises an outer circumferential surface 74 that separates an upstream end of the body part 60 from a downstream part of the body part by engaging in a passage wall 75 upstream of an ejector throat 77 ( Fig. 8). In the example shown, the outer circumferential surface 74 forms a circular sealing surface.

[0029] A propulsion flow passage 68 extends through the body part 60 along the central longitudinal axis A. In the illustrated example, a portion of the propulsion flow passage 68 extends transversely to the central longitudinal axis A and over at least one of the multiple recirculation flow passages 62. The portion of the propulsion flow passage 68 that extends transversely to the central longitudinal axis has an upstream edge with a radius of curvature that tapers to a leading edge along an upstream section relative to a flow direction through the body part 60. The multiple recirculation flow passages 62 are arranged circumferentially around the body part 60 and enclose the propulsion flow passage 68. An outlet 69 of the propulsion flow passage 68 is located distal to the recirculation flow outlets 66.

[0030] A plurality of tongue blades 70 at least partially enclose the corresponding recirculation flow outlets 66 in the body part 60 to prevent recirculation through the recirculation flow passages 62. In the example shown, the plurality of tongue blades 70 comprises six tongue blades 70, each attached to the body part 60 next to a proximal or upstream end of the tongue 70 with respect to a flow direction through the body part 60. The tongue blades 70 are located axially upstream of the outlet 69 of the propulsion flow passage 68 with respect to the longitudinal axis A ( Fig. 2).

[0031] As in the Fig. As shown in Figures 6-7, the leaves 70 comprise a base or a proximal end with a fastening opening 78 for engagement with the fastening element 80. The fastening element 80 can be an integral part of the body part 60, such as formed during a molding process with the multiple tongue leaves or by a hot-melt adhesive process. As shown in Fig. As shown in Figure 4, the recirculation flow outlets 66 are elongated and taper in width towards a distal end of the body part 60. Similarly, the tongue blades 70 taper in width towards a distal end. A feature of the tongue blades 70 and the recirculation flow passages 62 is that the flow of recirculated gases is directed by walls 71 between adjacent recirculation flow passages 62 in a direction parallel to the flow direction of the propellant gases through the propellant flow passage 68. This reduces the degree of rotation of the recirculation flow F before it is mixed with the propellant flow M from the fuel source 28.

[0032] Fig. Figure 9 shows a method 100 for operating the fuel cell system 20 with the injector / ejector 40 or the injector / ejector 140, which are disclosed below. In block 102, a motive flow M is drawn from the fuel source 28 into the motive flow passage 68 and through the body part 60 of an injector / ejector assembly 40 ( Fig. 8) directed. In the example shown, the driving current M flows through the driving current passage 68 transversely to the flow direction of a return current R before reversing and moving along the central longitudinal axis A of the body part 60. The driving current M exits the driving current passage 68 through the outlet 69 at the distal end of the body part 60 downstream of the recirculation flow outlets 66 before entering the passage 75.

[0033] In block 104, the recirculation flow R is directed from the anode outlet 24 on the fuel cell stack 22 into one of the recirculation flow passages 62 in the body section 60. The recirculation flow R flows through the passage 75 before entering the inlets 64 to the recirculation flow passages 62 in the body section 60. The recirculation flow R exits the body section 60 through the outlets 66 near the tongue blades 70. Ribs 82 are arranged in the passage 75 to limit the opening of the tongue blades 70 and to reduce the contact area between the ribs 82 and the wall of the passage 75, which could decrease the response time of the tongue blades 70 to changes in the flow through at least one of the recirculation flow passages 62 or the drive flow passage 68.

[0034] In block 106, the recirculation flow R and the motive flow M mix downstream of their respective outlets 66, 69, with the plurality of tongue blades at least partially enclosing a corresponding recirculation flow outlet 66. When the recirculation flow R and the motive flow M begin to mix downstream of the housing section 60, they pass through the ejector throat 77 in the passage 75. The ejector throat 77 comprises a longitudinal section of the passage 75 with a reduced cross-sectional area compared to the portion of the passage 75 containing the injector / ejector 40 and the portion of the passage 75 downstream of the ejector throat 77.

[0035] The Fig. Figures 10-14 show another example of an injector / ejector assembly 140. The injector / ejector assembly 140 is similar to the injector / ejector assembly 40, except for the locations described below or shown in the drawings. The similar features also include the addition of a leading “1”.

[0036] As in the Fig. As shown in Figures 10-14, the injector / ejector assembly 140 comprises a body part 160 extending along a central longitudinal axis A. A plurality of recirculation flow passages 162 extend through the body part 160 from a recirculation flow inlet 164 near a proximal end of the body part 160 to a recirculation flow outlet 166 near a distal end of the body part 160. Both the recirculation flow inlet and the recirculation flow outlets 164, 166 are defined at a circumference through the body part 160, with the cross-sectional area of ​​the recirculation flow outlets 166 being larger than the cross-sectional area of ​​the recirculation flow inlets 164.

[0037] The proximal end of the body part 160 comprises an outer circumferential surface 174 that separates an upstream end of the body part 160 from a downstream part of the body part 160. In one example, the outer circumferential surface 174 includes a passage 175 for receiving a seal, such as an O-ring seal, to create a seal with a body part contact surface 185 on a ribbed body part 181 that bears ribs 182. In the illustrated example, the outer circumferential surface 174 defines a circular sealing surface with a passage for receiving an O-ring.

[0038] A propulsion flow passage 168 extends through the body part 160 along the central longitudinal axis A. In the illustrated example, part of the propulsion flow passage 168 extends transversely to the central longitudinal axis A and over at least one of the multiple recirculation flow passages 162. The section of the propulsion flow passage 168 that runs transversely to the central longitudinal axis also has an upstream edge with a radius of curvature that tapers to a leading edge along an upstream section relative to a flow direction through the body part 160. The multiple recirculation flow passages 162 are arranged circumferentially around the body part 160 and enclose the propulsion flow passage 168. An outlet 169 of the propulsion flow passage 168 projects beyond the recirculation flow outlets 166.

[0039] A plurality of tongue blades 170 at least partially enclose the corresponding recirculation flow outlets 166 in the body part 160 to prevent recirculation through the recirculation flow passages 162. In the example shown, the plurality of tongue blades 170 comprises six tongue blades 170, each attached to the body part 160 adjacent to a proximal or upstream end of the tongue 170 relative to a flow direction through the body part 160. The tongue blades 170 are located axially upstream of the outlet 169 of the propulsion flow passage 168 relative to the longitudinal axis A ( Fig. 10). In the example shown, the tongue blades 170 are depicted in a fully open position.

[0040] The tongue blades 170 are limited in their movement by the ribs 182, which are integrally formed with a rib body part 181 that forms a ring surrounding the body part 160 and is fixed relative to it. The rib body part 181 includes a body part contact surface 185 configured to form a seal with the outer circumferential surface 174 of the body part 160. The rib body part 181 also includes an outer circumferential surface 187 with a passage 183 for receiving a seal, such as an O-ring seal, for engaging the passage wall 75 upstream of the ejector throat 77, similar to the one described in Fig. 8 injector / ejector shown 40.

[0041] As in the Fig. As shown in Figures 12-14, the tongue blades 170 comprise a base or proximal end with a fastening opening 178 for snapping fastening elements 180 onto the body part 160. As shown in Fig.As shown in Figure 13, the recirculation flow outlets 166 are elongated and taper in width towards a distal end of the body part 160. Similarly, the tongue blades 170 taper in width towards a distal end. A feature of the tongue blades 170 and the recirculation flow passages 162 is that the flow of recirculated gases is directed by walls 171 between adjacent recirculation flow passages 162 in a direction parallel to the flow direction of the propellant gases through the propellant flow passage 168. This reduces the degree of rotation of the recirculation flow F before it is mixed with the propellant flow M from the fuel source 28.

[0042] In one exemplary embodiment, the fuel cell system 20 is installed in or otherwise used in a vehicle, e.g., a motor vehicle. For the purposes of this definition, a "vehicle" is understood to be a device configured for the transport of persons, things, objects, or the like. Non-restrictive examples of motor vehicles (e.g., electric motor vehicles, including battery electric vehicles and fuel cell vehicles, or the like) include land vehicles (e.g., cars, trucks, motorcycles, electric bicycles, buses, trains, or the like), aircraft (e.g., airplanes, helicopters, unmanned aerial vehicles, or the like), watercraft (e.g., boats, watercraft, or the like), and amphibious vehicles (e.g., hovercraft, or the like). Furthermore, the fuel cell system 20 can be used as part of a stationary power generation system.

Claims

[1] Injector / ejector assembly (40) for a fuel cell, the assembly comprising: a body part (60) extending along a central longitudinal axis (A); a plurality of recirculation flow passages (62) formed by and extending through the body part (60), each of the plurality of recirculation flow passages (62) extending from a corresponding recirculation flow inlet (64) to a corresponding recirculation flow outlet (66); a motive current passage (68) formed by and extending through the body part (60); a plurality of tongue blades (70) enclosing at least part of the corresponding recirculation flow outlet (66) for each of the plurality of recirculation flow passages (62); wherein each of the plurality of tongue leaves (70) is attached to the body part (60) adjacent to an upstream end relative to a flow direction through the assembly; wherein the tongue blades (70) comprise six circumferentially spaced tongue blades (70) surrounding the body part (60); wherein the body part (60) has a base part with an outer circumferential surface (74) that separates each of the corresponding recirculation flow inlets (64) from the corresponding recirculation flow outlet (66) for each of the plurality of recirculation flow passages (62); and with a plurality of ribs extending from a rib body section which is attached relative to the body section, the plurality of ribs being arranged radially outward from a corresponding plurality of tongue blades. [2] Injector / ejector assembly according to claim 1, wherein the majority of the recirculation flow passages (62) are arranged circumferentially around the body part (60). [3] Injector / ejector assembly according to claim 1, wherein the plurality of tongue blades (70) each taper from a base to a distal end. [4] Injector / ejector assembly according to claim 1, wherein at least a part of the motive current passage (68) extends along the central longitudinal axis (A). [5] Injector / ejector assembly according to claim 1, wherein the motive flow passage (68) has an outlet at a distal end of the body part (60) which is arranged downstream with respect to the central longitudinal axis of the recirculation flow outlet (66). [6] Injector / ejector assembly according to claim 4, wherein part of an inlet to the motive flow passage (68) lies transversely to the plurality of recirculation flow passages (62). [7] Injector / ejector assembly according to claim 1, wherein a proximal end of each of the multiple tongue leaflets (70) is fixed against movement relative to the body part (60).

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