Jet pump unit with a metering valve for controlling a gaseous medium

Abstract

Jet pump unit (46) comprising a pump housing (49), a metering valve (1) with a valve housing (2), a mixing tube section (52), an intake channel (43) and a discharge section (45), wherein a through-bore (42) forming a through-opening (80) is formed in the pump housing (49), wherein the metering valve (1) is received in the through-opening (80) and a first stage (200) and a second stage (202) for radially centering and guiding the metering valve (1) in the pump housing (49) are formed in the through-opening (80) radially to a longitudinal axis (40) of the jet pump unit (46), characterized in that an inlet channel (17) is formed in the metering valve (1), which inlet channel (17) is formed radially to the longitudinal axis (40) of the jet pump unit (46) at least partially in the pump housing (49) and in the passage opening (80) leads to,wherein the valve housing (2) is arranged with a step (37) on the pump housing (49) and is firmly connected to it, preferably by means of screw elements (35),

Description

[0001] The invention relates to a jet pump unit with a metering valve for controlling a gaseous medium, in particular hydrogen, for example for use in vehicles with fuel cell drive. State of the art

[0002] DE 10 2010 043 618 A1 describes a jet pump unit with a metering valve for controlling a gaseous medium, in particular hydrogen, wherein the metering valve comprises a valve housing, an ejector unit, an actuator, and a closing element. A through-opening is formed in the valve housing, which can be opened or closed by the closing element at a valve seat. The ejector unit comprises an inlet section to which a first gaseous medium is supplied under pressure, a suction section where a second medium is present, and a mixing tube section from which a mixture of the first and second gaseous media exits. The through-opening is arranged between the inlet section and the suction section of the ejector unit.

[0003] US patent 2017 / 0244116A1 discloses a fuel gas circuit device comprising a body, a fuel gas supply channel, an exhaust channel, an injector, and a diffuser. An elastic element is provided at a connecting part between the injector and the diffuser.

[0004] US 2009 / 0317691A1 shows an ejector for a fuel cell system, consisting of an ejector body with an inlet opening, an outlet opening, a diffuser, a mechanism for regulating the nozzle hole section, and a bearing element.

[0005] JP 2008 - 196 458 A describes an ejector and a pulse transport pump that transports fluid by means of the entrainment effect of a working fluid.

[0006] US 9 598 990 B2 describes an ejector arranged to allow a working fluid to flow in order to create a vacuum, and to cause a target fluid to flow by the effect of the vacuum.

[0007] EP 1 319 896 A2 discloses a device for premixing fuel and air to provide a fuel-air mixture comprising a mixing tube.

[0008] Optimization of purging processes in an anode path of a fuel cell assembly can be achieved through a combination of a metering valve and a jet pump. Precise geometric alignment of the components is necessary for optimal operation. Advantages of the invention

[0009] The jet pump unit according to the invention with a metering valve for controlling a gaseous medium, in particular hydrogen, has the advantage that, through optimized integration of the metering valve into the jet pump unit, a precise centering of the metering valve in the jet pump unit and thus an improved operating function is achieved.

[0010] The jet pump unit comprises a pump housing, a metering valve with a valve body, a mixing tube section, an intake channel, and a discharge section. A through-bore forming a through-opening is provided in the pump housing. The metering valve is accommodated in this through-opening, with a first stage and a second stage extending radially to a longitudinal axis of the jet pump unit within the through-opening for radial centering and guidance of the metering valve within the pump housing. An inlet channel is formed in the metering valve, which extends radially to the longitudinal axis of the jet pump unit, at least partially within the pump housing, and opens into the through-opening. The valve body is arranged on the pump housing with a stage and rigidly connected to it, preferably by means of a screw element.This allows for optimal integration of the metering valve into the pump housing in a simple design.

[0011] The formation of a first and second stage in the through-bore improves the coaxiality between the metering valve and the pump housing of the jet pump unit. This allows for better mixing between the recirculated gaseous medium and the gaseous medium from the metering valve.

[0012] In a first advantageous embodiment, the metering valve comprises a nozzle with a through-channel, the nozzle being arranged coaxially in the jet pump unit upstream of the mixing tube section by means of the first and second stages. This minimizes angular errors of the metering valve within the pump housing.

[0013] In a further embodiment of the invention, it is advantageously provided that

[0014] In a further advantageous design, the first stage is arranged axially above the inlet channel in the direction of the screw element, and the second stage is arranged axially below the inlet channel in the direction of the suction area. This results in low angular tolerances of the metering valve in the pump housing.

[0015] In a further embodiment of the invention, it is advantageously provided that the through-bore is at least partially conical, with a discharge channel of the jet pump unit extending radially to the longitudinal axis of the jet pump unit within the pump housing in the conical region of the through-bore. Advantageously, the inlet channel opens into an inflow area within the metering valve, the inflow area being formed in the through-opening of the jet pump unit. By integrating the metering valve into the pump housing of the jet pump unit, it is possible to direct the flow of the gaseous medium directly into the jet pump unit. This allows for an optimized design of the metering valve and the jet pump unit.

[0016] The described jet pump unit is particularly suitable for use in a fuel cell arrangement to control the hydrogen supply to an anode area of ​​a fuel cell. Advantages include low pressure fluctuations in the anode path and quiet operation. Drawings

[0017] The drawing shows exemplary embodiments of a jet pump unit according to the invention and a metering valve for controlling a gas supply, in particular hydrogen, to a fuel cell. It shows in Fig. 1 An embodiment of a metering valve with a nozzle in longitudinal section, Fig. 2 an embodiment of a jet pump unit according to the invention with the in Fig. 1. Metering valve shown in longitudinal section, Fig. 3 an enlarged section of the jet pump unit from the Fig. 2 in the area of ​​the passage opening, showing only the right side.

[0018] Components with the same function were designated with the same reference number. Description of the exemplary embodiment

[0019] Fig. Figure 1 shows a metering valve 1, as used in a jet pump unit 46 according to the invention, in longitudinal section. The metering valve 1 has a valve housing 2 with an interior 3. An electromagnet 26 is arranged in the interior 3, which comprises a solenoid coil 12, an inner pole 14 and an outer pole 13.

[0020] Furthermore, a movable magnetic armature device 25 is arranged in the interior space 3. The magnetic armature device 25 comprises a magnetic armature 8 and a connecting element 9, which is received in a recess 22 of the magnetic armature 8 and is thus firmly connected to the magnetic armature 8, for example by a weld or by crimping. The magnetic armature 8 is designed as a plunger armature and is received in the inner pole 14. The inner pole 14 has a recess 21 with a recess edge 24 into which the magnetic armature 8 plunges during its stroke movement.

[0021] On the inner pole 14, first bearing bushings 60 are arranged in a recess 34, in which the connecting element 9 is received and guided on a first guide section 6 of the inner pole 14. Furthermore, second bearing bushings 70 are arranged on the valve housing 2, in which a piston-shaped section 23 of the connecting element 9 is received and guided in a second guide section 7. The piston-shaped section 23 of the connecting element 9 is made of a material with high mechanical strength.

[0022] The metering valve 1 further comprises a nozzle 15, which has a cup-shaped section 151 with a base 1510 and a pin 152. The valve housing 2 is received in the cup-shaped section 151 of the nozzle 15 with a pin-shaped end 38 facing away from the electromagnet 26, the valve housing 2 bearing against a counter-surface 153 of the nozzle 15 with a surface 381. An adjusting element 36 is arranged between the pin-shaped end 38 of the valve housing 2 and the nozzle 15.

[0023] This is one possible embodiment of the nozzle 15. Alternatively, the nozzle 15 can also be received in the valve housing 2 of the metering valve 1 and firmly connected to it.

[0024] The connecting element 9 is rigidly connected at one end to a closing element 10. The closing element 10 has an elastic sealing element 11 at its end facing away from the connecting element 9. The elastic sealing element 11 interacts with a valve seat 19 formed on the base 1510 of the nozzle 15, such that when the elastic sealing element 11 rests on the valve seat 19, a passage 18 formed in the nozzle 15 is closed. The valve seat 19 is designed as a flat seat.

[0025] A spring chamber 30 is formed in the inner pole 14, which forms part of the interior space 3. A closing spring 4 is arranged in the spring chamber 30, which is supported between the inner pole 14 and a disc-shaped end 5 of the connecting element 9. The closing spring 4 exerts a force on the magnetic armature device 25 in the direction of the valve seat 19.

[0026] Furthermore, the interior space 3 comprises a magnetic armature chamber 300 in which the magnetic armature 8 is arranged. The magnetic armature chamber 300 is connected to the spring chamber 30 via a connecting channel 16. At its end facing the closing element 10, the magnetic armature 8 borders an inlet area 28, which can be filled with a gaseous medium, for example hydrogen, via an inlet channel 17 arranged radially with respect to a longitudinal axis 40 of the metering valve 1 of the jet pump unit 46 and formed in the valve housing 2.

[0027] The valve housing 2 and the inner pole 14 are magnetically and mechanically connected to each other via a magnetic throttle 20. Advantageously, they can be formed as a single unit. The magnetic throttle 20 comprises a thin-walled cylindrical web 201 and a conical area 2020, forming an annular groove 301 in the magnetic armature chamber 300.

[0028] The one-piece form of valve housing 2 and inner pole 14 merely shows one possible embodiment and can, however, be omitted just like the throttle point 20.

[0029] The operation of metering valve 1 is as follows: When the solenoid coil 12 is not energized, the closing element 10 is pressed against the valve seat 19 by the closing spring 4, so that the connection between the inlet area 28 and the flow channel 18 is interrupted and no gas flow occurs.

[0030] When the solenoid coil 12 is energized, a magnetic force is generated on the magnetic armature 8, which opposes the closing force of the closing spring 4. This magnetic force is transmitted via the connecting element 9 to the closing element 10, so that the closing force of the closing spring 4 is overcompensated and the closing element 10, together with the elastic sealing element 11, lifts off the valve seat 19. Gas flow through the metering valve 1 is thus enabled.

[0031] The stroke of the closing element 10 can be adjusted via the current applied to the solenoid 12. The higher the current at the solenoid 12, the greater the stroke of the closing element 10 and the higher the gas flow rate in the metering valve 1, since the force of the closing spring 4 is dependent on the stroke. If the current at the solenoid 12 is reduced, the stroke of the closing element 10 is also reduced, thus throttling the gas flow rate.

[0032] When the current to the solenoid coil 12 is interrupted, the magnetic force on the magnetic armature 8 is reduced, thus decreasing the force on the closing element 10 by means of the connecting element 9. The closing element 10 moves towards the passage channel 18 and seals against the valve seat 19 with the elastic sealing element 11. The gas flow in the metering valve 1 is interrupted.

[0033] The metering valve 1 of the jet pump unit 46 according to the invention can, for example, be used in a fuel cell arrangement. Hydrogen from a tank can be supplied to an anode area of ​​the fuel cell by means of the metering valve 1. Depending on the current applied to the solenoid coil 12 of the metering valve 1, which actuates the stroke of the closing element 10, the flow cross-section at the passage 18 is thereby changed such that the gas flow supplied to the fuel cell is continuously adjusted according to demand.

[0034] The metering valve 1 for controlling a gaseous medium thus offers the advantage that the supply of the first gaseous medium and the metering of hydrogen into the anode area of ​​the fuel cell can be carried out much more precisely by electronically controlled adjustment of the flow cross-section of the passage 18 while simultaneously regulating the anode pressure. This significantly improves the operational reliability and durability of the connected fuel cell, as hydrogen is always supplied in a superstoichiometric proportion. Furthermore, consequential damage, such as damage to a downstream catalyst, can also be prevented.

[0035] Fig. Figure 2 shows an embodiment of a jet pump unit 46 according to the invention with the metering valve 1 in longitudinal section. The jet pump unit 46 has a jet pump housing 41, which includes the valve housing 2 of the metering valve 1 and a pump housing 49. The jet pump unit 46 has a longitudinal axis 40, which is identical to the longitudinal axis of the metering valve 1.

[0036] In the pump housing 49, a partially stepped and partially conical through-bore 42 is formed axially to the longitudinal axis 40, and a suction channel 43 and the inlet channel 17 of the metering valve 1 are formed radially to the longitudinal axis 40. The through-bore 42 includes a suction section 44, a mixing tube section 52, and a discharge section 45. The metering valve 1 is coaxially mounted in a through-opening 80 of the through-bore 42 within the pump housing 49. The valve housing 2 is arranged on the pump housing 49 with a step 37 and is firmly connected to it by several screw elements 35. Sealing elements 53 are also arranged on the valve housing 2 and on the nozzle 15, so that the valve housing 2 and the pump housing 49 are sealed against each other. Gaseous medium from the inlet channel 17 thus only reaches the intake area 44 via the passage channel 18.

[0037] At the end region of the pump housing 49 facing away from the metering valve 1, a drain channel 48 is formed radially to the longitudinal axis 40 in the pump housing 49, wherein the through-bore 42 at the end region of the pump housing 49 facing away from the metering valve 1 is sealed with a cover 50.

[0038] Furthermore, as in Fig.Figure 3 shows an enlarged representation of the pump housing 49. Within the through-opening 80 of the pump housing 49, in which the metering valve 1 with its valve housing 2 is received, a first stage 200 and a second stage 202 are formed radially to the longitudinal axis 40. This allows the valve housing 2 of the metering valve 1 to be guided radially within the pump housing 49 and aligned accordingly in the through-bore 42, ensuring precise and angular alignment of the nozzle 15 of the metering valve 1 with respect to the mixing tube section 52. The first stage 200 is arranged radially above the inlet channel 17 in the direction of the electromagnet 26, and the second stage 202 is arranged below the inlet channel 17 in the direction of the suction area 44.A gap is formed between the metering valve 1 and the first stage 200 and between the metering valve 1 and the second stage 202, so that the metering valve 1 does not rest on the first stage 200 and / or on the second stage 202. Functioning of the jet pump unit 46

[0039] With the valve seat 19 of the metering valve 1 open or partially open, gaseous medium, in this case hydrogen, flows from the tank through the supply channel 17 of the metering valve 1 and into the flow channel 18 in the nozzle 15. After exiting the nozzle 15 and entering the through-bore 42 in the intake area 44, this hydrogen encounters gaseous medium that has already been supplied to the fuel cell but not consumed, and which has been returned to the jet pump unit 46 via the intake channel 43. The returned gaseous medium consists mainly of hydrogen, but This also includes water vapor and nitrogen. In the mixing tube section 52, a mass flow is drawn in from the intake section 44 by momentum exchange of the gaseous media and conveyed towards the outlet section 45 and thus towards the anode section of the fuel cell. Depending on the geometry of the through-bore 42 and the insertion angle of the metering valve 1 and thus of the nozzle 15, the gas flow supplied to the fuel cell can be adjusted as required.

Claims

[1] Jet pump unit (46) comprising a pump housing (49), a metering valve (1) with a valve housing (2), a mixing tube section (52), a suction channel (43) and a discharge section (45), wherein a through-bore (42) forming a through-opening (80) is formed in the pump housing (49), wherein the metering valve (1) is received in the through-opening (80) and a first stage (200) and a second stage (202) for radially centering and guiding the metering valve (1) in the pump housing (49) are formed in the through-opening (80) radially to a longitudinal axis (40) of the jet pump unit (46), characterized by, that an inlet channel (17) is formed in the metering valve (1), which inlet channel (17) is formed radially to the longitudinal axis (40) of the jet pump unit (46) at least partially in the pump housing (49) and opens into the through-opening (80), wherein the valve housing (2) is arranged with a step (37) on the pump housing (49) and is firmly connected to it, preferably by means of screw elements (35) [2] Jet pump unit (46) according to claim 1, characterized by , that the metering valve (1) comprises a nozzle (15) with a passage channel (18), wherein the nozzle (15) is arranged coaxially in the jet pump unit (46) in front of the mixing tube area (52) by means of the first stage (200) and the second stage (202). [3] Jet pump unit (46) according to claim 1 or 2, characterized by, that the first stage (200) is arranged axially above the inlet channel (17) in the direction of the screw elements (35) and the second stage (202) is arranged axially below the inlet channel (17) in the direction of a suction area (44). [4] Jet pump unit (46) according to one of the preceding claims, characterized by , that the through-bore (42) is at least partially conical, wherein a discharge channel (48) of the jet pump unit (46) is formed radially to the longitudinal axis (40) of the jet pump unit (46) in the pump housing (49) in the conical area of ​​the through-bore (42). [5] Jet pump unit (46) according to claim 4, characterized by , that the inlet channel (17) opens into an inflow area (28) within the metering valve (1), wherein the inflow area (28) is formed in the through-opening (80) of the jet pump unit (46). [6] Fuel cell arrangement with a jet pump unit (46) for controlling a hydrogen supply to a fuel cell according to one of the preceding claims.

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