Fluid line assembly for fuel cell vehicle

Abstract

The invention relates to a fluid line assembly (20) for a fuel cell vehicle, the fluid line assembly (20) having a main branch (21) passing through a fuel cell unit (26) and a secondary branch (22) branching off from the main branch. In order to optimize the fluid regulation in a branch line of a fuel cell vehicle, according to the invention the secondary branch (22) has a flow restrictor (1), which comprises a pipe element (2), the inner cross-section of which decreases downstream with respect to the flow direction (D), and a piston element (6), the piston element (6) being arranged in the pipe element (2). The piston element (6) can be moved at least partially downstream along a movement path (V) in the tube element (2) against a restoring force (F) from an open position to a limiting position in which a channel current-carrying cross-section formed between the piston element (6) and the tube element (2) is smaller than the channel current-carrying cross-section formed in the open position.

Description

Technical Field

[0001] The invention relates to a fluid line assembly for a fuel cell vehicle having the features of the preamble of claim 1 and a flow restrictor having the features of the preamble of claim 10 . Background Art

[0002] In the case of fuel cell vehicles, there is a known practice of using a compressor to achieve an optimal air flow through the fuel cell. In some cases, the compressor is also referred to as a "turbocharger" even if it is not connected to a turbine. A small part of the mass flow (i.e. the air flow from the compressor) can be diverted from the main flow through a branch line in order to flow through another component. For example, the component can thus be cooled and / or ventilated to limit gas concentrations or dust concentrations, etc. For example, a limited air flow is required for the ventilation of the fuel cell housing. A small part of fresh air passes through the housing. If the fuel cell is cooled by a liquid coolant, an ion exchange filter is required to keep the coolant free of ions. For this purpose, an ion exchange filter can be arranged on a branch line of the coolant circuit, through which a limited mass flow passes. A limited mass flow of coolant can also be used for water / air coolers. In these and other applications, on the one hand, it is necessary to maintain a certain mass flow through the branch line, while on the other hand a certain mass flow should not be too large, in particular to avoid compromising the mass flow through the main line.

[0003] Different speeds of the compressors result in different mass flows through the branch lines, and this can be disadvantageous. To alleviate this problem, a throttle valve can be used, but this must be activated and controlled, requires a lot of installation space and increases costs. Such a throttle valve can also have a fail-safe position, in which the throttle valve is completely closed or completely open. However, both solutions are unsuitable because too much air or no air at all passes through the throttle valve. Similar problems can also occur with branch lines within the coolant circuit.

[0004] Document DE 10 2015 006 720 B4 discloses a flow limiter for a compressed gas container. The flow limiter comprises a protective tube having a valve opening arranged at a first end for connection to a gas valve and a compressed gas container opening arranged at a second end, a first valve seat mounted on the valve opening, and a second valve seat mounted on the compressed gas container opening, a piston which can be moved from an outflow position through an open position to a filling position in the protective tube and is acted upon by a spring on both sides, wherein the piston has a first opening which is open for flow in both positions, a second opening which is closed in the outflow position, and a third opening which is closed in the filling position, wherein the second opening and the third opening are open for flow in the open position.

[0005] In view of the prior art pointed out, there is still room for improvement in flow regulation in branch lines of fuel cell vehicles. Summary of the invention

[0006] A basic object of the invention is to optimize the flow regulation in a branch line of a fuel cell vehicle.

[0007] According to the invention, this object is achieved by a fluid line assembly having the features of claim 1 , wherein the dependent claims relate to advantageous embodiments of the invention.

[0008] It should be noted that the features and measures presented individually in the following description can be combined with one another in any technically feasible manner and indicate further embodiments of the invention. The description particularly additionally characterizes and explains the invention in detail together with the drawings.

[0009] The present invention provides a fluid line assembly for a fuel cell vehicle. A fuel cell vehicle is a vehicle, such as a passenger vehicle or a heavy goods vehicle, which is powered by a fuel cell unit. In the fuel cell unit, there is an electrochemical conversion of reactants, wherein the electrical energy obtained can be used to operate a drive motor and other components or alternatively can be temporarily stored in a battery. In particular, one reactant can be oxygen extracted from the ambient air. Another reactant can be hydrogen, but alternatives such as low molecular weight alcohols or ammonia are also conceivable. The fluid line assembly is used to receive and carry fluid in a working state. The fluid line assembly has at least one pipeline, typically a plurality of pipelines. However, the fluid line assembly can also have other components, such as a device for conveying a fluid, such as a pump or a compressor. The fluid can be in a liquid or gaseous state.

[0010] The fluid piping assembly has a main branch passing through the fuel cell unit and a secondary branch branching out from the main branch. The main branch and the secondary branch form part of the fluid piping assembly. Each branch preferably has at least one fluid pipeline. The terms "main branch" and "secondary branch" are mainly used to distinguish them and should not be interpreted as a limitation on the size of the branch or its design in other aspects. However, the main branch can be designed to carry a larger mass flow than the secondary branch, that is, for example, the main branch can have a larger cross-section. The main branch passes through the fuel cell unit, that is, the main branch can carry the fluid to the fuel cell unit in the working state and can take the fluid away from the fuel cell unit. The composition of the fluid may change when the fluid passes through the fuel cell unit. The fuel cell unit has at least one fuel cell. As an option, the fuel cell unit may also have a component that assists or enables the function of the actual fuel cell. The secondary branch branches out from the main branch, and in particular the secondary branch can branch out from the upstream of the fuel cell unit, but it may also branch out from the downstream of the fuel cell unit. It is possible, but not absolutely necessary, that the secondary branch should also re-enter the main branch. The secondary branch can pass through additional components, which can in principle be any component of a fuel cell vehicle. In this case, the secondary branch is designed to carry the fluid to the additional component and take the fluid away from the additional component. Also in this case, the composition of the fluid can be changed.

[0011] According to the invention, the secondary branch has a flow restrictor, which comprises a tube element, the inner cross section of which decreases downstream relative to the flow direction, and a piston element, the piston element being movable against a restoring force along a movement path in the tube element at least partially from an open position downstream to a restricted position, the flow-carrying cross section of the channel formed between the piston element and the tube element being smaller in the restricted position than in the open position. The function of the flow restrictor is to ensure that the mass flow through the secondary branch does not vary too much. In particular, the mass flow through the secondary branch should not be too large in order to prevent undersupply of the main branch.

[0012] The flow restrictor has a pipe element. The pipe element is provided for receiving a fluid and being flowed by the fluid. Therefore, the pipe element has a watertight design. The pipe element can be connected to a fluid pipeline of a secondary branch upstream and / or downstream, or can also form a part of such a fluid pipeline. The interior of the pipe element can be characterized by an internal cross-section, which is not constant along the pipe element but decreases downstream relative to the flow direction. The flow direction corresponds to the general direction of movement of the fluid in the working state. In some embodiments, the flow direction can correspond to the axis of symmetry of the pipe element. With respect to the working state, an "upstream" direction, i.e., a direction opposite to the flow, and a "downstream" direction, i.e., a direction consistent with the flow, can be further defined. The internal cross-section of the pipe element decreases downstream. The reduction can be staged or continuous. The internal cross-section can be limited to a portion of the pipe element, which can be referred to as a tapered portion or a restricted portion. The internal cross-sections upstream and downstream of this portion can be constant. It is also conceivable that the internal cross-section outside this portion increases upstream (or decreases downstream).

[0013] In addition, the flow restrictor has a piston element, which can be moved downstream from the open position to the restricted position at least partially along the movement path in the tube element against the restoring force, and the flow-carrying cross section of the channel formed between the piston element and the tube element in the restricted position is smaller than the flow-carrying cross section of the channel formed in the open position. The piston element is arranged inside the tube element and can move along the movement path in the tube element. The movement path is preferably straight, but can also be at least partially curved. The piston element can move from the open position to the restricted position, wherein the movement occurs at least partially downstream. The movement can also occur partially transversely to the flow direction, that is, there may be a vector component of the movement path oriented transversely to the flow direction. However, in general, the movement at least partially downstream means that the piston element moves into a region with a smaller internal cross section of the tube element. As a result, the cross section of the channel between the tube element and the piston element can be reduced toward the restricted position. However, even in the restricted position, there is a cross section of the channel (not equal to zero), that is, even in this position, the fluid can flow between the tube element and the piston element. However, the cross section of the channel is larger in the open position, more particularly due to the changing internal cross section of the tube element. The inflowing fluid exerts a force on the piston element in a downstream direction, i.e. it is pushed in the direction of the restricted position. However, according to the invention, this occurs against a restoring force. This restoring force can be generated in various ways, ensuring that the piston element moves only when there is a sufficient mass flow in the direction of the restricted position and that the piston element moves backwards in the direction of the open position when the mass flow decreases. The term "piston element" should not be interpreted as a restriction in terms of shape or in other aspects of the design. It indicates that the piston element can move within the tube element, just like a piston in a cylinder. The piston element can also be designated as a displacement element or a restriction element in other ways, for example.

[0014] In general, the flow limiter allows limiting the mass flow through the secondary branch. If there is an excessive increase in the mass flow, the piston element is pushed in the direction of the limiting position by the force of the inflowing fluid, the cross section of the channel is reduced, and the mass flow is limited. Thus, too much fluid can be prevented from flowing through the secondary branch and too little fluid can be prevented from flowing through the main branch. However, the mass flow is not interrupted by the secondary branch, so that the auxiliary components arranged therein can be continuously supplied.

[0015] According to one embodiment, the fluid line assembly is designed as a coolant loop, wherein the main branch is used to cool the fuel cell unit. The coolant is preferably a liquid coolant, such as water, a water / ethylene glycol mixture, etc. The coolant loop can pass through different components other than the fuel cell unit. In this process, some components can also be heated or temperature-controlled, and the coolant releases heat to the components. It will be understood that the coolant loop can also pass through a heat exchanger or a main cooler, where the coolant can release heat to the surrounding air. In addition, the coolant loop is usually assigned a pump, which can be operated by a dedicated motor or can be mechanically connected to the drive motor of the fuel cell vehicle. For example, the additional component through which the secondary branch passes can be an ion exchange filter. According to another embodiment, the fluid line assembly is designed as an air line assembly, wherein the main branch is used to supply air to the fuel cell unit. After passing through the fuel cell unit, the moisture-rich air can be discharged by an exhaust device. The additional component through which the secondary branch passes can be the housing of the fuel cell unit. This usually has to be ventilated to prevent the hydrogen concentration from exceeding the limit value.

[0016] One embodiment design piston element has at least one recess, the recess opens outwards toward the tube element, extends at least partially in the flow direction and at least partially defines the cross section of the channel. A recess is formed at the periphery of the piston element. The recess opens outwards and is therefore toward the tube element. The recess extends at least partially in the flow direction, wherein the extension direction of the recess can correspond to the flow direction in a certain area or certain areas. However, the recess can also extend at an angle to the flow direction completely or partially. Since the flow direction is defined as the axial direction, the recess can preferably extend at least partially axially and / or radially. If the recess extends partially in the tangential direction, this will result in a tangential deflection of the inflowing fluid, which can cause unnecessary friction losses in some cases. However, in principle this is not excluded either. In particular, the piston element can have a plurality of recesses, which are spaced apart at least in a certain area or certain areas. The recess can be a groove, a slit or a channel-type design. A zone or rib can be formed between two recesses. The cross section of the channel can be adjusted by the number, width and depth of the recess. Regarding assembly, it is conceivable that the tube element is combined with different piston elements according to demand. For example, individual recesses may be defined by contours of circular and / or polygonal cross-sections.

[0017] Alternatively or in addition, the pipe element can have at least one depression, which opens inwardly toward the piston element, extends at least partially in the flow direction and at least partially defines the cross section of the channel. A depression is formed inside the pipe element. The depression opens inwardly and is therefore toward the piston element. The depression extends at least partially in the flow direction, wherein the extension direction of the depression can correspond to the flow direction in some areas or a certain area. However, the depression can also extend at an angle to the flow direction completely or partially. If the flow direction is defined as an axial direction, the depression can preferably extend at least partially axially and / or radially, but a partial tangential route is also conceivable. The pipe element can have a plurality of depressions, and a plurality of depressions are spaced apart at least in some areas or a certain area. The depression can be a groove, a slit or a channel type design. A zone or rib can be formed between two depressions. In this embodiment as well, the cross section of the channel can be adjusted by the number, width and depth of the depression. For example, a single depression can be defined by the profile of a circular and / or polygonal cross section.

[0018] According to one embodiment, in the limiting position, there is no direct contact between the piston element and the tube element. That is, the piston element and the tube element are spaced apart and form a surrounding gap between them, which defines the cross section of the channel. Another preferred embodiment is designed so that in the limiting position, the piston element is in contact with the tube element. In particular, the contact can be in a plurality of mutually separated areas. The above-mentioned recess can be arranged between these areas. The contact with the tube element enables the position of the piston element to be better defined, i.e., to prevent unnecessary movement. Accordingly, this enables the cross section of the channel and the resulting mass flow to be more accurately defined.

[0019] Preferably, the tube element has a guide element, which interacts with the piston element in a form-fitting manner and the piston element can move between the open position and the restricted position in a guided manner along the guide element. The guide element engages with a complementary structure of the piston element. For example, a groove in which the guide element engages can be formed on the piston element. Conversely, the guide element itself can have a groove in which the piston element engages. In any case, the guide element forms a form-fitting joint with the piston element transverse to the movement path. At least in some embodiments, it can also be said that the guide element extends along the movement path and / or defines the movement path according to its route. The guide element can be formed integrally with the tube element or alternatively, the guide element can be produced separately and connected to the tube element.

[0020] Fundamentally, guiding on the periphery would be conceivable, wherein the guide element engages in a groove or the like on the periphery, which groove is formed on the piston element. On the other hand, a preferred embodiment designs the guide element to pass through a through opening, which passes through the piston element. The through opening passes through the piston element and is generally surrounded by the material of the piston element. In particular, the through opening can be arranged in the center of the piston element. This has the advantage that the force exerted by the inflowing fluid is evenly distributed around the through opening. Asymmetric force distribution may cause the guide element to tilt in the through opening. The guide element can be of rod-shaped design. Since the guide element passes through the through opening in the piston element, the guide element is arranged inside the tube element, at a certain distance from the wall of the tube element. The guide element can be connected to the wall by at least one retaining element.

[0021] For example, the restoring force can be generated by the weight of the piston element. In this case, the limit position can be set higher than the open position relative to the vertical line defined by the gravity, for example, it can also be vertically above the open position. When the fluid pipeline assembly carries a liquid (such as a coolant) in the working state, it is also conceivable that if the open position is set higher than the limit position, the restoring force is generated by the buoyancy of the piston element. However, in some cases, this force is too small to be reliably returned. In addition, there are limitations on the positioning of the flow limiter in this case, and this may also be unnecessary. Therefore, a preferred embodiment designs that the flow limiter has an elastic return element, which generates a restoring force and pushes the piston element to the open position. The return element can also be referred to as a spring element. The spring element can be directly or indirectly arranged between the tube element and the piston element. At the same time, it is not ruled out that the spring element is formed integrally with the piston element or the tube element. That is to say, the piston element (or tube element) and the spring element can be parts of the same component, wherein, for example, the elastic deformation of the spring element can be achieved by a small material thickness.

[0022] One embodiment design flow limiter has at least one stop element, and the stop element limits the movement of the piston element in the restricted position and / or in the open position by the form-fitting engagement with the piston element. For example, the stop element can be formed integrally with the pipe element. However, the stop element can also be produced separately in advance and connected to the pipe element, for example, by form-fitting engagement, friction engagement and / or material bonding. The stop element is preferably stationary relative to the pipe element. The stop element forms a stopper of the piston element, thereby limiting the movement of the piston element. In other words, when the piston element reaches the stop element, a form-fitting engagement occurs, and the piston element is stopped. This may be related to the restricted position, that is, the piston element stops when the restricted position is reached. Alternatively or in addition, this may also be related to the open position. The form-fitting engagement between the piston element and the stop element is at least partially applied in the direction of the moving path. A single stop element can be provided for two positions, or a stop element can be provided for each position. It is also possible that the stop element is connected to the above-mentioned guide element or even formed integrally with the guide element here. For example, the retaining element can act as a stop element at the same time. It is also conceivable that the return element acts as a stop element, for example a helical spring which is completely compressed in the limit position and no longer acts in an elastic manner but rather acts as a rigid body inserted between the tube element and the piston element.

[0023] Furthermore, the present invention provides a flow restrictor, in particular a flow restrictor for a fluid line assembly according to the present invention. According to the present invention, the flow restrictor comprises a tube element, the inner cross section of the tube element decreases downstream relative to the flow direction, and a piston element, the piston element can be moved downstream from an open position to a restricted position at least partially against a restoring force along a movement path in the tube element, in which the flow-carrying cross section of the channel formed between the piston element and the tube element is smaller than the flow-carrying cross section of the channel formed in the open position.

[0024] The terms mentioned have already been explained above with reference to the fluid line assembly according to the invention and are therefore not explained again. Advantageous embodiments of the flow restrictor according to the invention correspond to those of the fluid line assembly according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Further advantageous details and effects of the present invention are explained in detail below by means of exemplary embodiments illustrated in the drawings. More specifically: Figure 1 A schematic diagram showing components of a fuel cell vehicle having a first fluid line assembly according to the present invention; Figure 2 A schematic diagram showing components of a fuel cell vehicle having a second fluid line assembly according to the present invention; Figure 3 A cross-sectional view showing a first embodiment of a flow restrictor according to the present invention; Figure 4 Display along Figure 3 A cross-sectional view along line IV-IV in FIG. Figures 5A-5C A perspective sectional view showing a second embodiment of a flow restrictor according to the invention in different states; Figure 6 A cross-sectional view showing a third embodiment of a flow restrictor according to the present invention; and Figure 7-13 A schematic diagram showing a piston element for a flow restrictor according to the invention. DETAILED DESCRIPTION

[0026] In the various figures, identical parts are always provided with the same reference symbols, for which reason they are also generally described only once.

[0027] Figure 1A schematic diagram of a portion of a fuel cell vehicle with a first fluid line assembly 20 (in this case an air line assembly) according to the invention is shown. The first fluid line assembly 20 has a main branch 21, in which an electric compressor 24 generates an air flow. Ambient air is sucked in through an air filter 23. Downstream of the compressor 24, the main branch 21 first passes through a water-cooled charge air cooler 25 and then through a fuel cell unit 26. There, some of the oxygen contained in the air is electrochemically converted together with hydrogen, as a result of which the oxygen content in the air is reduced and its moisture content is increased. The corresponding air flow is discharged to the surrounding environment. A secondary branch 22 branches off from the main branch 21 at the charge air cooler 25. This secondary branch 22 passes through the housing 27 of the fuel cell unit 26 and then leads to the main branch 21 again upstream of the compressor 24. Since the secondary branch 22 passes through the housing 27, the air contained therein is constantly exchanged, thereby preventing the accumulation of hydrogen.

[0028] The flow limiter 1 according to the invention is arranged upstream of the housing 27, in the region of the secondary branch 22. This flow limiter limits the mass flow of air within the secondary branch 22, thereby ensuring, on the one hand, a sufficient air flow through the housing 27 regardless of variations in the output of the compressor 24 over time, while, on the other hand, preventing any possible undersupply of the fuel cell unit 26 in the main branch 22.

[0029] Figure 2 Another schematic diagram of a portion of a fuel cell vehicle with a second fluid line assembly 20 according to the invention, in this case a coolant circuit, is shown. The second fluid line assembly 20 has a closed-circuit main branch 21 in which an electric pump 28 generates a circulating air flow, in which the coolant is cooled by heat exchange with the ambient air in a radiator 29. Downstream of the pump 28, the main branch 21 first passes through a particle filter 30 and then through a fuel cell unit 26 and a housing 27 of the fuel cell unit 26. The main branch 21 then leads back to the radiator 29, where a secondary branch 22 branches off from the main branch 21. This secondary branch 22 passes through an ion exchange filter 31 and then re-enters the main branch 21 again upstream of the radiator 29. Also in this case, the secondary branch 22 has a flow restrictor 1 according to the invention.

[0030] Different exemplary embodiments of flow restrictors 1 are explained below, which can in principle be used in the illustrated air line arrangement and in the illustrated coolant circuit.

[0031] Figure 3A cross-sectional view of a first embodiment of a flow restrictor 1 according to the invention is shown. The flow restrictor 1 has a pipe element 2, which is connected in a watertight manner to an adjacent portion of a secondary branch 22 in the assembled state. The pipe element 2 has a restriction portion 3, in which its internal cross-section decreases downstream with respect to the intended flow direction D. The general shape of the restriction portion 3 is a truncated cone, although a plurality of groove-type recesses 4 are formed in the interior, which extend partially in the flow direction D. Rib portions 5 are formed between the recesses 4. A piston element 6 is arranged in the pipe element 2, more precisely in its restriction portion 3, which in the present case is of spherical design with a smooth surface. The piston element 6 can be moved between an open position and a downstream restriction position along a movement path V extending parallel to the flow direction D. Here, in Figure 3 The ends of the movement path V indicated in correspond to the positions of the center point of the piston element 6 in the open position and in the restricted position, respectively. Figure 3 The piston element 6 is shown in an intermediate position.

[0032] By Figure 3 The partially closed geometry of the piston element 6, which is illustrated as a sphere in the examples of the other figures, may also take some other shape, such as a cone, a frustoconical, an ellipse or some other shape which is movably arranged in the pipe element 2. The configuration of the piston element 6 can be optimized in terms of flow, so that possible turbulence downstream of the piston element 6 can be reduced.

[0033] The piston element 6 is pushed in the direction of the open position by a return element 8, in this case a helical spring, which is supported on the tubular element 2 via a support element 7. More precisely, the return element 8 generates a restoring force F which increases with the distance of the piston element 6 from the open position.

[0034] In order to prevent the piston element 6 from moving beyond the open position, an annular first stop element 9 is connected to the pipe element 2 upstream of the restriction portion 3. In a similar manner, the end region of the rib portion 5 located downstream can act as a second stop element 10, which prevents the piston element 6 from moving downstream beyond the intended restriction position.

[0035] Figure 4 Displays the corresponding Figure 34. In the cross-sectional view of the line IV-IV in FIG. 2 , it can be seen that the recess 4 is defined by an arcuate profile. However, alternatively, it can also be a polygon, such as a rectangle. It is obvious that even when the piston element 6 is in contact with the rib portion 5 on the outside in the limiting position, there is still a flow cross section between the piston element 6 and the tube element 2, and the fluid can pass through the flow cross section. When the piston element moves in the direction of the open position, there is an additional gap that opens upward between the piston element and the rib portion 5, as a result of which the flow cross section increases. When the fluid pipeline assembly 20 is working, there is a fluid flowing from the upstream of the piston element 6, generating a force opposite to the restoring force F. Generally, the corresponding force increases with the mass flow through the auxiliary part 21. On the other hand, the piston element is pushed in the direction of the limiting position against the restoring force F, as a result of which the flow cross section is reduced and the increase in mass flow is limited.

[0036] Figures 5A-5C A second embodiment of a flow restrictor 1 according to the invention is shown. This is again a tube element 2 with a tapering restriction section 3, although in this case this section is of smooth design. The piston element 6 is not designed as a smooth sphere on the one hand, but has a plurality of recesses 11, which extend partially along the flow direction D. Again, rib sections 12 are formed between these recesses 11, which represent sections of a spherical surface. Again, the piston element 6 is acted upon by a return element 8, which is supported on the tube element 2 by a support element 15. A guide element 14, which in this example is of cylindrical rod-like design, is fixed to this support element 15 and to another support element 15 connected to the tube element 2 in an upstream position. The guide element passes through a through opening 13 in the piston element 6. Thus, the guide element 14 defines the course of the movement path V by its shape. In this example, the support element 15 arranged upstream can also serve as a stop element defining the open position. Figure 5A The piston element 6 is shown in a restricted position in which the rib section 12 is in contact externally with the tube element 2. Also in this case, due to the recess 11, there is a flow cross section between the piston element 6 and the tube element 2. Figure 5B An intermediate position is shown, in which the return element 8 has been further extended. The rib section 12 is no longer in contact with the pipe element 2, as a result of which the flow cross section increases. Figure 5C The flow cross section increases to a maximum value in the open position of the piston element 6, in which the piston element 6 is held by the support element 15. Due to the guidance of the guide element 14, the movement path V and the position of the piston element 6 are more accurately defined.

[0037] Figure 6A third embodiment of a flow limiter 1 according to the invention is shown, which is essentially identical to the second embodiment and will therefore not be explained again. However, in this case, the return element 8 has been omitted. In this case, the restoring force F is generated by the weight force G acting on the piston element 6. Here, the flow limiter 1 must be installed in such a way that at least a sufficiently large proportion of the weight force is directed upstream. In an alternative (not shown here), it is also conceivable to use a piston element 6 with a density significantly lower than that of the fluid, so that the buoyancy can act as the restoring force F. In this case, the flow limiter 1 would have to be mounted relative to the piston element 6. Figure 6 Install in reverse order as shown in the figure.

[0038] Figures 7 to 13 Different embodiments of piston elements 6 are shown which can be used, for example, with the second and third embodiments of the flow restrictor 1. In this case, in particular, it is also conceivable to combine the tube element 2 with different piston elements 6 as required. Figures 7 to 10 Each shows a piston element 6 with six recesses 11, which are of channel-like design and are delimited by a curved profile. A rib portion 12 is formed between every two recesses 11. The individual recesses 11 of the embodiments are of different sizes, thereby defining a cross section of the channel that is maintained in the restricted position. Figure 7 The depression 11 in is the largest, while in Figure 8 , Fig. 9 and Fig.10 They become smaller and smaller. Fig. 9 Corresponding to Figures 5A-5C and Figure 6 The piston element 6 is shown in FIG.

[0039] Figures 11 to 13 Each shows a piston element 6 with eight recesses 11, which are cut into the piston element 6 in the manner of slits and are delimited by a polygonal contour. A rib section 12 is also formed between every two recesses 11. The individual recesses 11 of the exemplary embodiments differ in size, more precisely in their depth. In this way, too, the cross section of the passage that is maintained in the limiting position can be defined. Fig.11 The middle depression 11 is the deepest, while Fig.12 and Fig.13 They become increasingly shallow.

[0040] List of reference numerals: 1Flow restrictor 2 pipe elements 3 Restrictions 4.11 Depression 5.12 rib part 6 Piston element 7, 15 Supporting elements 8 Return element 9, 10 Stop element 13Through opening 14 Guide elements 20 Fluid pipeline components 21. Main branch 22 Secondary branch 23 Air filter 24 compressor 25 Charge air cooler 26 fuel cell units 27 Shell 28 Pumps 29 Radiator 30 particle filter 31 Ion exchange filter D Flow direction FResilience G-Gravity VMovement Path

Claims

1. A fluid pipeline assembly (20) for a fuel cell vehicle, the fluid pipeline assembly (20) having a main branch (21) passing through a fuel cell unit (26) and a secondary branch (22) branching off from the main branch, It is characterized in that The secondary branch (22) has a flow restrictor (1), which comprises a pipe element (2) and a piston element (6), wherein the inner cross section of the pipe element (2) decreases downstream relative to the flow direction (D), and the piston element (6) resists a restoring force (F) and moves at least partially downstream from an open position to a restricted position along a movement path (V) in the pipe element (2), wherein in the restricted position a flow-carrying cross section of a channel formed between the piston element (6) and the pipe element (2) is smaller than a flow-carrying cross section of the channel formed in the open position.

2. The fluid line assembly according to claim 1, It is characterized in that The component is designed as a coolant circuit, wherein the main branch (21) is used to cool the fuel cell unit (26), or the component is designed as an air line component, wherein the main branch (21) is used to supply air to the fuel cell unit (26).

3. The fluid line assembly according to any one of the preceding claims, It is characterized in that The piston element (6) has at least one recess (11), which is open outwardly toward the tube element (2), extends at least partially in the flow direction (D) and at least partially defines the cross section of the channel.

4. The fluid line assembly according to any one of the preceding claims, It is characterized in that The tube element (2) has at least one recess (4), which is open inwardly toward the piston element (6), extends at least partially in the flow direction (D) and at least partially defines the cross section of the channel.

5. The fluid line assembly according to any one of the preceding claims, It is characterized in that In the restricted position, the piston element (6) is in contact with the tube element (2).

6. The fluid line assembly according to any one of the preceding claims, It is characterized in that The tube element (2) has a guide element (14) which interacts with the piston element (6) in a form-fitting manner and along which the piston element (6) is moved in a guided manner between the open position and the limit position.

7. The fluid line assembly according to any one of the preceding claims, It is characterized in that The guide element (14) passes through a through-opening (13), and the through-opening (13) passes through the piston element (6).

8. The fluid line assembly according to any one of the preceding claims, It is characterized in that The flow restrictor (1) has an elastic return element (8) which generates the restoring force (F) and pushes the piston element (6) toward the open position.

9. The fluid line assembly according to any one of the preceding claims, It is characterized in that The flow limiter (1) has at least one stop element (9, 10) which limits the movement of the piston element (6) in the limiting position and / or in the opening position by form-fitting engagement with the piston element (6).

10. A flow restrictor (1), in particular for use in a fluid line assembly (20) according to any one of the preceding claims, It is characterized in that The flow restrictor (1) comprises a tube element (2) and a piston element (6), wherein the inner cross section of the tube element (2) decreases downstream relative to the flow direction (D), and the piston element (6) moves at least partially downstream from an open position to a restricted position along a movement path (V) in the tube element (2) against a restoring force (F), wherein the flow-carrying cross section of the channel formed between the piston element (6) and the tube element (2) is smaller than the flow-carrying cross section of the channel formed in the open position.

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