Valve device and method for operating a valve device

Abstract

The present invention relates to a valve device (10), for example for a hydrogen jet pump device in a fuel cell application, comprising a main channel (MC) and at least one bypass channel (BC) within a valve body, a tappet (TP), and a spring (SP) which is arranged at one end of the tappet (TP).

Description

[0001] Description

[0002] title and method for operating a

[0003] The present invention relates to a valve device, for example for a hydrogen jet pump device (with such a valve device) in a fuel cell application, and a method for operating a valve device, for example for a hydrogen jet pump device in a fuel cell application.

[0004] State of the art

[0005] In fuel cell systems, a recirculation loop is typically connected to the anode side of the fuel cell, and a hydrogen gas injector (HGI) may be used in the hydrogen supply path. In some configurations, customer requirements necessitate the use of an additional HGI, for example, to fill a bypass channel with fresh hydrogen directly from the tank and divert it to a jet pump in the recirculation loop. The use of a second HGI may result in increased space requirements in the hydrogen supply path.

[0006] Document DE 10 2020 212 178 A1 describes the operation of a fuel cell.

[0007] Disclosure of the invention

[0008] The invention relates to a valve device, for example for a hydrogen jet pump device in a fuel cell application, according to claim 1 and a method for operating a valve device, for example for a hydrogen jet pump device in a fuel cell application, according to claim 8.

[0009] Further embodiments are the subject of the dependent claims.

[0010] Advantages of the invention

[0011] The idea on which the invention is based relates to a valve device, for example for a hydrogen jet pump device, and a method for operating a valve device, for example for a hydrogen jet pump device in a fuel cell application, by which a simplification of the system and its use with regard to supplying the valve with energy is achieved, since there is only one electrical valve instead of the usual two, thus requiring less power from the ECU. Furthermore, a reduction in product size in the customer system layout and also in weight of approximately 30% less can be achieved, as well as a product cost reduction due to fewer subcomponents used. Even with these improvements, the valve device can still be able to fulfill multiple functions required for the jet pump and / or the fuel cell system.

[0012] The invention relates to a valve device, for example for a hydrogen jet pump device in a fuel cell application, comprising: a main channel and at least one bypass channel within a valve body, extending from an inner recess in the valve body, and a main seat at an entrance to the main channel and a bypass seat at an entrance to the bypass channel from the inner recess or at a gas inlet into the valve body, for example a hydrogen inlet, wherein the main seat and the bypass seat are arranged at the inner recess and at a predefined distance from each other along the inner recess;a plunger insertable into the inner recess, and a main sealing element arranged on the plunger at a position facing the main seat and configured to close the main seat when the plunger is pushed toward the main seat, and at least one bypass sealing element arranged on the plunger at a position facing the bypass seat and configured to close the bypass seat when the plunger is pushed toward the bypass seat, wherein the plunger, when inserted into the inner recess, provides a predefined gap between the plunger and the valve body, between the inlet of the gas (for example, hydrogen) into the valve body and the bypass seat and / or between two bypass seats;and a spring disposed at one end of the plunger and configured to urge the plunger toward the main seat, and an electromagnet configured to pull the plunger against a spring force to various stages when energized.;

[0013] The valve device can thus also be referred to as a variable mode valve since the outlets / channels can be kept open or closed at different stages due to the different stages of the power supply to the electromagnet and the amount of hydrogen flowing through the channels can depend on the power supply state.

[0014] The operation (opening / closing) of the main and bypass channels can correspond to one HGI (Hydrogen Gas Injection) dosing function and at the same time to another HGI dosing function.

[0015] Since the function of two such HGI dosing valves can be achieved by the valve device, multiple HGI dosing valves are not required. Thus, the conditions associated with conventional systems with two HGI valves, which typically lead to an increase in system size in terms of energy consumption, space and weight (30% increase), and costs (>45% due to the additional valve and lines), can be avoided or reduced in their effect with the valve device according to the invention.

[0016] The inner recess may extend in a longitudinal direction of the valve body and in the center of the valve body. Closing the main and / or bypass seat may correspond to sealing the inlet to the corresponding channel so that no, or only a minimal amount of, hydrogen flows into the channel. The gap provides a flow path in terms of leakage between the hydrogen inlet and the bypass channel along the space between the tappet and the valve body, for example to its nozzle or wall at the inner recess. A nozzle may be arranged in the valve body, wherein the inner recess then also represents an opening in the nozzle for the gas inlet, which is connected to the main and bypass channels, and the tappet can be pressed into the nozzle within this opening and seal at least one of the channels at the corresponding seat.

[0017] The valve device can in principle also be used for a feed unit, a natural application and pressure control devices and generally for various applications other than fuel systems, for example for concepts for dosing the mass flow of a fluid or for splitting flows or for two different functions based on a load condition.

[0018] According to one embodiment of the invention, the valve body has a first bypass seat at the gas (e.g., hydrogen) inlet and a second bypass seat at the entrance to the bypass channel, wherein the inserted plunger provides a gap between the plunger and the valve body at a path between the first bypass seat and the second bypass seat.

[0019] According to one embodiment of the invention, the tappet can be raised to a predefined minimum level at which the main channel remains closed and gas can flow with a predefined minimum amount between the first bypass seat and the second bypass seat along the gap (leakage).

[0020] When the tappet is lifted, the seal of the bypass sealing element may open slightly and allow leakage into the gap.

[0021] According to one embodiment of the invention, the electromagnet is configured to lift the plunger into a slightly open position, a medium open position, and a fully open position. According to one embodiment of the invention, in the slightly open position, the gas (e.g., hydrogen) flows along a gap to the bypass channel; in the medium open position, the gas flows along the gap to the bypass channel and directly to the main channel; and in the fully open position, the gas flows directly to the bypass channel and to the main channel.

[0022] In the fully open position, a direct flow path to the bypass channel and to the main channel can exist and there is no longer any leakage flow.

[0023] According to one embodiment of the invention, the bypass channel and the main channel extend through a nozzle of the valve device.

[0024] According to one embodiment of the invention, the main sealing element is arranged at a tip of the tappet and the bypass sealing elements are rings arranged at a position of the tappet facing the bypass seat when it is inserted into the inner recess.

[0025] The valve device in the above sense can be a dosing device valve with a special nozzle with elastomer seal(s) on the tappet, which can seal the valve seats (for example, on the nozzle) of the bypass channel and the main channel. The valve can be capable of providing different functional modes with hydrogen flow through different channels according to the different power supply from the ECU, in particular a zero-fill state as a state without power supply to the electromagnet, or a pre-fill state for the system by providing leakage only via a gap to the bypass channel, or as a pre-fill plus standard fill stage with a standard fill to the main channel (to the jet pump) and with a small flow (leakage) to the bypass, or as a standard fill stage with full opening to the main channel and to the bypass.

[0026] The invention relates to a method for operating a valve device, for example for a hydrogen jet pump device in a fuel cell application, comprising a step of providing a valve device according to the invention; receiving information about a desired gas flow to a fuel cell system; maintaining the electromagnet without power supply and the plunger in a closed position when there is no gas demand, or supplying the electromagnet with power and providing a gas flow through the bypass channel and / or through the main channel.

[0027] According to one embodiment of the invention, the electromagnet is energized to a predefined slight level and the plunger is lifted to a slightly open position so that gas (for example, hydrogen) can flow along a gap to the bypass channel.

[0028] According to one embodiment of the invention, the electromagnet is energized to a predefined average level and the plunger is lifted to a predefined average open position so that gas (for example, hydrogen) can flow at a predefined average amount along the gap to the bypass channel and directly to the main channel.

[0029] According to one embodiment of the invention, the electromagnet is energized to a predefined full level and the plunger is lifted to a predefined fully open position so that gas (for example, hydrogen) can flow to the bypass channel and to the main channel at a predefined full amount.

[0030] The valve device may also be characterized by the features and advantages of the method of operating the valve device and vice versa.

[0031] Further features and advantages of embodiments will become apparent from the following description with reference to figures.

[0032] Description of the characters

[0033] The invention is explained in more detail by the description of the schematic figures. Fig. 1a shows a schematic view of a valve device according to an embodiment of the invention;

[0034] Fig. 1 b shows an enlarged schematic view of a valve device according to Fig. 1;

[0035] Fig. 2 shows a schematic view of a valve device according to an embodiment of the invention in the closed state;

[0036] Fig. 3 shows a schematic view of a valve device according to an embodiment of the invention in a first open state;

[0037] Fig. 4 shows a schematic view of a valve device according to an embodiment of the invention in a second open state;

[0038] Fig. 5 shows a schematic view of a valve device according to an embodiment of the invention in a third open state;

[0039] Fig. 5a shows a schematic view of a valve device according to an embodiment of the invention in general view;

[0040] Fig. 6 shows a diagram of operating stages of the valve device according to the embodiments of the invention; and

[0041] Fig. 7 shows a system layout of the anode side of a fuel cell system with a valve device according to an embodiment of the invention.

[0042] In the figures, identical or corresponding elements are designated by the same reference numerals.

[0043] Fig. 1a shows a schematic view of a valve device according to an embodiment of the invention. Fig. 1a shows a general view of the valve device 10 in the closed state. In this state, hydrogen can flow in through the hydrogen inlet H1, but the valve 10 closes all channels, so that no or substantially no hydrogen flows through the main channel MC and through the bypass channel BC.

[0044] The valve device 10 comprises a main channel MC and at least one bypass channel BC within a valve body, for example, within a nozzle NZ, extending from an inner recess IR in the valve body and in the nozzle NZ, and a main seat MS at an inlet to the main channel MC and a bypass seat BS at an inlet to the bypass channel BC from the inner recess IR (of the nozzle) or at a hydrogen inlet to the valve body, wherein the main seat MS and the bypass seat BS are arranged at the inner recess IR and at a predefined distance from each other along the inner recess IR. Furthermore, the valve device 10 comprises a tappet TP insertable into the inner recess IR as an opening in the nozzle, and a main sealing element MSE arranged on the tappet TP at a position facing the main seat MS and designed to close the main seat MS.when the plunger is pushed toward the main seat MS, and at least one bypass sealing element BSM arranged on the plunger TP at a position facing the bypass seat BS and configured to close the bypass seat BS when the plunger is pushed toward the bypass seat BS, wherein the plunger, when inserted into the inner recess IR, provides a predefined gap between the plunger TP and the valve body VB (inside of the nozzle), between the inlet of the hydrogen into the valve body VB and the bypass seat BS and / or between two bypass seats BS; and a spring SP arranged at one end of the plunger TP and configured to push the plunger TP toward the main seat MS, and an electromagnet E configured to pull the plunger TP against a spring force to various stages when energized. The bypass channel BC can lead to a bypass outlet BOUT.

[0045] Fig. 1 b shows an enlarged schematic view of a valve device according to Fig. 1 . The tappet TP with the main sealing element MSE at its tip region can be pressed towards the inlet of the main channel MC and seal the inlet of the main channel MC such that hydrogen flow to the main channel MC can be substantially prevented. In this position of the tappet TP, the bypass sealing elements BSM, for example O-rings, at the upper first bypass seat BS1 and at the lower (second) bypass seat BS2 can seal the hydrogen flow. In other words, the bypass sealing element BSM at the upper first bypass seat BS1 can block the hydrogen from the hydrogen inlet H1 so that it does not enter the gap CL between the two bypass seats BS1 and BS2 (and extends along the tappet between them and between the tappet and the valve body VB).In addition, the bypass sealing element BSM at the lower second bypass seat BS2 can prevent the hydrogen from flowing into the bypass channel(s) BC (to the channel inlet ET).

[0046] Fig. 2 shows a schematic view of a valve device according to an embodiment of the invention in the closed state.

[0047] Fig. 2 shows an enlarged view of the nozzle interior with the channels MC and BC, the sealing elements BSM, the hydrogen inlet Hl, and the bypass outlet BSOUT shown in Fig. 1a in the closed state. In this stage (zero filling), the electromagnet is not energized, and the spring presses the plunger, and the elastomer seals seal all valve seats on the nozzle.

[0048] Fig. 3 shows a schematic view of a valve device according to an embodiment of the invention in a first open state. State F1 according to Fig. 6 is shown.

[0049] The electromagnet is energized to a predefined minimum level, and the plunger TP can be lifted upwards from the main position (or at least against the spring force) into a slightly open position. This corresponds to a so-called pre-fill stage, which does not open the main channel to hydrogen flow (at least not to a significant extent) and triggers only a small flow of hydrogen through leakage along the gap CL from the first bypass seat BS1 and the second bypass seat BS2 to the inlet to the bypass channel and further to the bypass outlet BOUT. The electromagnet can be energized with a low current value, and the plunger TP begins to move upwards, opening the first bypass seat BS1 at the hydrogen inlet H1 and the second bypass seat BS2 at the bypass channel, while the valve seat of the main channel MC is still sealed.The controlled clearance CL between the nozzle NZ (the valve body) and the tappet TP allows a small amount of hydrogen to be delivered through the bypass channels, which is useful for activating the fuel cell system. A prefill mass flow can be determined by the tappet stroke (based on the seal design and current value), the bypass channels (number and diameter), and the size of the clearance CL between the tappet TP and the nozzle NZ. In other words, the bypass sealing elements BSM allow a small amount of hydrogen to flow while the main sealing element MSE keeps the main channel closed / sealed.

[0050] Fig. 4 shows a schematic view of a valve device according to an embodiment of the invention in a second open state. State F2 according to Fig. 6 is shown.

[0051] Fig. 4 also shows the tip of the nozzle NZ, through which the main channel MC passes. In the stage shown in Fig. 4, the electromagnet is more strongly energized and the tappet TP opens further to a medium open position. In this position, the main sealing element MSE also lifts, allowing a defined flow to the main channel. In this stage, flow can also be present between the first bypass seat BS1 and the second bypass seat BS2 along the leak (as in Fig. 3). The stage according to Fig. 4 corresponds to a so-called standard filling by a jet pump, in which the electromagnet can be energized with a medium current value and the tappet begins to move further upwards, opening the main channel seat MS, and the jet pump begins to pump hydrogen through the mixing tube (the main channel) into the stack.The flow through the space between the tappet and the nozzle is also ensured as pre-filling.

[0052] Fig. 5 shows a schematic view of a valve device according to an embodiment of the invention in a third open state. State F3 according to Fig. 6 is shown.

[0053] The stage shown in Fig. 5 can provide additional mass flow through the BSOUT channel and through the main channel MC, allowing the electromagnet to be energized at a high current. The main channel still supplies hydrogen through the mixing tube into the stack, and the bypass in this stage is no longer a leak, but rather a predefined flow with the plunger fully open and the maximum current. When the plunger TP reaches its maximum stroke, the gap between the plunger TP and the nozzle NZ increases, and additional hydrogen mass flow can also reach the stack through the bypass channel.

[0054] Fig. 5a shows a schematic view of a valve device according to an embodiment of the invention in general view.

[0055] The valve device is formed from a main channel MC and at least one bypass channel (not shown) within a valve body, for example within a nozzle NZ.

[0056] The nozzle NZ may be located at a fixed position within the valve and has an opening for receiving gas and the tappet TP and has a main seat MS at an inlet to the main channel MC and a bypass seat BS at an inlet to the bypass channel BC, wherein the main seat MS and the bypass seat BS are arranged at a predefined distance from each other.

[0057] Furthermore, the valve device 10 comprises a tappet TP which can be inserted into the inner recess of the nozzle (its opening), and a main sealing element MSE which is arranged on the tappet TP at a position facing the main seat MS and is designed to close the main seat MS when the tappet is pressed towards the main seat MS, and at least one bypass sealing element BSM which is arranged on the tappet TP at a position facing the bypass seat BS and is designed to close the bypass seat BS when the tappet is pressed towards the bypass seat BS, wherein the tappet provides a predetermined gap between the tappet TP and the valve body VB (nozzle), between the inlet of the hydrogen into the valve body VB and the bypass seat BS and / or between two bypass seats BS.

[0058] Fig. 6 shows a diagram of operating stages of the valve device according to the embodiments of the invention.

[0059] In Fig. 6, the flow characteristic of a jet pump is explained in a clockwise direction in the first quadrant of the diagram, the valve flow characteristic in relation to the primary flow in the second quadrant of the diagram and the plunger movement characteristic in relation to the flow in the third quadrant.

[0060] In the 1st quadrant: F1 indicates the pre-fill stage, where the valve only allows leakage flow through the bypass channel BC into the system. F2 indicates the flow of hydrogen into the main channel along with the leakage flow into the BC channel (to meet the standard flow characteristic of the steel pump). Finally, F3 indicates the hydrogen flow from the main channel as in function F2 in addition to the bypass flow at full opening.

[0061] Fig. 7 shows a system layout of the anode side A of a fuel cell system. The hydrogen flows from the tanks T into the main circuit. Additional valves, such as a shut-off valve, pressure reducing valves, and pressure relief valves, can be added to this branch. A system according to the invention has only the valve device 10, which is connected between the hydrogen inlet and the recirculation blower / recirculation circuit, whereas a system according to the prior art would typically require an additional HGI (designated HGI-2) (for example, without a nozzle for the bypass channel), which can, however, be avoided when using the invention (shown only in light lines). The recirculation path can be connected to the anode A and can include a purge valve PV, a water separator WA, and a connection to the cathode K.The invention is not limited to the embodiments shown, but can be modified in various ways within the scope of the invention.

Claims

Claims 1. Valve device (10) comprising: - a main channel (MC) and at least one bypass channel (BC) within a valve body (VB), extending from an inner recess (IR) in the valve body (VB), and a main seat (MS) at an entrance to the main channel (MC) and a bypass seat (BS) at an entrance to the bypass channel (BC) from the inner recess (IR) or at a gas inlet into the valve body (VB), wherein the main seat (MS) and the bypass seat (BS) are arranged at the inner recess (IR) and at a predefined distance from each other along the inner recess (IR); - a tappet (TP) insertable into the inner recess (IR), and a main sealing element (MSE) arranged on the tappet (TP) at a position facing the main seat (MS) and designed to close the main seat (MS) when the tappet is pushed toward the main seat (MS), and at least one bypass sealing element (BSM) arranged on the tappet (TP) at a position facing the bypass seat (BS) and designed to close the bypass seat (BS) when the tappet is pushed toward the bypass seat (BS), wherein the tappet, when inserted into the inner recess (IR), provides a predefined gap between the tappet (TP) and the valve body (VB), between the inlet of the gas into the valve body (VB) and the bypass seat (BS) and / or between two bypass seats (BS); and - a spring (SP) arranged at one end of the plunger (TP) and designed to push the plunger (TP) towards the main seat (MS), and an electromagnet designed to pull the plunger (TP) against a spring force in different stages when energized.

2. Valve device (10) according to claim 1, wherein the valve body (VB) has a first bypass seat (BS1) at the gas inlet and a second bypass seat (BS2) at the entrance to the bypass channel (BC), and wherein the inserted plunger (TP) provides a gap between the plunger (TP) and the valve body (VB) on a path between the first bypass seat (BS1) and the second bypass seat (BS2) 3. Valve device (10) according to claim 2, wherein the tappet (TP) can be raised to a predefined minimum level at which the main channel (MC) remains closed and gas can flow with a predefined minimum amount between the first bypass seat (BS1) and the second bypass seat (BS2) along the gap.

4. Valve device (10) according to one of claims 1 to 3, wherein the electromagnet is designed to lift the plunger (TP) into a slightly open position, a medium open position and a fully open position.

5. Valve device (10) according to claim 4, wherein in the slightly open position gas flows along a gap to the bypass channel and in the middle open position gas flows along the gap to the bypass channel and directly to the main channel and in the fully open position gas flows directly to the bypass channel and to the main channel.

6. Valve device (10) according to one of claims 1 to 5, wherein the bypass channel (BC) and the main channel (MC) extend through a nozzle of the valve device (10).

7. Valve device (10) according to one of claims 1 to 6, wherein the main sealing element (MSE) is arranged at a tip of the tappet (TP) and the bypass sealing element (BSM) is a ring arranged at a position of the tappet (TP) facing the bypass seat (BS) when inserted into the inner recess (IR).

8. Method for operating a valve device (10) comprising the following steps: - Providing a valve device (10) according to one of claims 1 to 7; - Receiving information about a desired gas flow; - Keeping the electromagnet without power supply and the plunger (TP) in a closed position when there is no gas demand, or supply energizing the electromagnet and providing a gas flow through the bypass channel (BC) and / or through the main channel (MC).

9. The method of claim 8, wherein the electromagnet is energized to a predefined slight level and the plunger is lifted to a slightly open position so that gas can flow along a gap to the bypass channel.

10. The method of claim 8, wherein the electromagnet is energized to a predefined intermediate level and the plunger is raised to a predefined intermediate open position so that gas can flow at a predefined intermediate amount along the gap to the bypass channel and directly to the main channel.

11. The method of claim 8, wherein the electromagnet is energized to a predefined full level and the plunger is raised to a predefined fully open position so that gas can flow at a predefined full amount to the bypass channel and to the main channel.

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