Water separator

Abstract

The invention relates to a water separator (1) for a fuel cell system (17). The invention also relates to the fuel cell system (17) comprising the water separator (1).

Description

[0001] Water separator

[0002] The invention relates to a water separator, in particular for a fuel cell system, according to the preamble of claim 1. The invention also relates to the fuel cell system with the water separator.

[0003] In a water separator, water contained in an air stream in the form of water droplets is separated from the air stream by centrifugal forces. To do this, the air stream is set in rotation in a duct and the water or water droplets are pressed against an outer wall of the duct by centrifugal force. A wall film forms on the outer wall of the duct, which is ultimately led through a gap or opening into a collection container. In the collection container, the air stream containing the separated water has a lower speed than the air stream in the duct and the water can settle out of the air stream. Unfortunately, the incoming air stream forms a pressure cushion in the collection container, which prevents or disrupts the discharge of the separated water through the gap or opening into the collection container.

[0004] The object of the invention is therefore to provide an improved or at least alternative embodiment for a water separator, in particular for a fuel cell system, of the generic type, in which the described disadvantages are overcome. The object of the invention is also to provide a corresponding fuel cell system with the water separator.

[0005] This object is achieved according to the invention by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims.

[0006] The present invention is based on the general idea of ​​relieving the pressure cushion in the collecting container at specific positions and thereby improving the effectiveness of the water separator. The water separator according to the invention is intended or designed in particular for a fuel cell system. The water separator has a housing through which air can flow and has an inlet leading into the housing and an outlet leading out of the housing. The housing also has a collecting container formed inside the housing and a separation gap formed inside the housing. The housing further has an inlet channel, an outlet channel, and a collecting channel. The inlet channel is provided for the air laden with water droplets and leads inside the housing from the inlet to the separation gap. The outlet channel is provided for the air discharged of water droplets and leads inside the housing from the inlet channel to the outlet.In other words, the inlet channel and the outlet channel can merge fluidically into one another within the housing. The collecting channel is provided for the water separated from the air and leads inside the housing from the inlet channel through the separating gap into the collecting container. In other words, the inlet channel and the collecting channel can be fluidically connected to one another within the housing via the separating gap. The outlet channel and the collecting channel are fluidically separated downstream from the separating gap. In other words, the separating gap is located at a transition point between the inlet channel and / or the collecting channel and / or the outlet channel. According to the invention, the collecting container and the inlet channel are fluidically connected to one another by means of at least one opening formed upstream of the separating gap.In other words, the opening fluidically connecting the collecting container and the inlet channel is a different opening from the separation gap.

[0007] Unless expressly stated otherwise, the terms "first," "second," etc., e.g., first guide or first ribs, are used below to distinguish different elements from one another. The presence of a first guide or rib or a second guide or rib does not necessarily imply that more than one guide or rib must be present.

[0008] The air laden with water droplets can, in particular, contain a comparatively high concentration of water droplets or large water droplets. The air laden with water droplets can, in particular, be the exhaust air of a fuel cell of the fuel cell system. The air discharged of water droplets can, in particular, be at least partially free of water droplets or larger water droplets. The air discharged of water droplets can, in particular, contain a comparatively small concentration of water droplets or no large water droplets. The air discharged of water droplets can, in particular, be fed to a humidifier or a turbocompressor or other components of the fuel cell system, thereby protecting them from damage or functional impairment by water droplets. The water separated from the air can, in particular, be composed of water droplets separated from the air laden with water droplets.

[0009] The housing can, in particular, have exactly one opening or several—in particular exactly two or exactly three or more—openings. If the housing has multiple openings, the respective openings can be spaced apart from one another and / or distributed and / or radially offset from one another on the circumference of the inlet channel. The respective openings can lie in a plane oriented transversely to the air flow direction. The respective openings can be arranged in one plane in one air flow direction.

[0010] The respective opening can communicatively connect the inlet channel to the collecting container in a direction axial with respect to the outlet channel or in a direction parallel to a longitudinal central axis of the outlet channel. In other words, the respective opening can have a central axis, wherein the central axis of the respective opening can be aligned parallel to the axial direction with respect to the outlet channel or parallel to the air flow direction of the outlet channel or parallel to the longitudinal central axis of the outlet channel. The flow-through cross-section of each of the openings arranged in the axial direction with respect to the outlet channel and / or the sum of the flow-through cross-sections of all the openings arranged in the axial direction with respect to the outlet channel can preferably be less than 25%, in particular less than 15%, and greater than 7% of a flow-through cross-section of the inlet channel.Alternatively, the respective opening can connect the inlet channel to the collecting container in a radial direction with respect to the outlet channel or in a direction radial to a longitudinal central axis of the outlet channel. In other words, the respective opening can have a central axis, wherein the central axis of the respective opening can be aligned almost perpendicular to the air flow direction of the outlet channel or to the longitudinal central axis of the outlet channel. The flow-through cross-section of each of the openings arranged in the radial direction with respect to the outlet channel and / or the sum of the flow-through cross-sections of all the openings arranged in the radial direction with respect to the outlet channel can preferably be less than 5%, in particular less than 2%, and greater than 0.1% of a flow-through cross-section of the inlet channel.

[0011] In a properly oriented water separator, the respective opening can be located above a water-fillable area of ​​the collection container. In a properly oriented water separator, a water-fillable area of ​​the collection container can be arranged in such a way that the water can collect in the water-fillable area by gravity. In particular, in a properly oriented water separator, the collection container or at least a water-fillable area of ​​the collection container can be located or arranged below the inlet channel and / or the outlet channel and / or the collection channel and / or the separation gap and / or the inlet and / or the outlet.

[0012] As it flows through the water separator, the air laden with water droplets flows into the inlet and further through the inlet channel to the separation gap. In the inlet channel, the air can be set into rotation - as described in more detail below. This creates a water film on the outer wall of the inlet channel, which flows to the separation gap. The air discharged from the water droplets flows further in the inlet channel to the separation gap. At the separation gap, the water separated from the air and the air discharged from the water droplets separate. The air discharged from the water droplets flows through the outlet channel to the outlet and further out of the water separator to the outside. The water separated from the air flows through the separation gap into the collection channel and then into the collection container.

[0013] As water flows into the collection tank, air also flows into the collection tank. The respective opening formed upstream of the separation gap connects the collection tank to the inlet channel so that the air flowing into the collection tank can escape from the collection tank back into the inlet channel. This relieves the pressure cushion in the collection tank and reduces the pressure difference between the inlet channel and the collection channel at the separation gap. Accordingly, the separated water can flow unhindered through the separation gap into the collection tank, improving the overall effectiveness of the water separator. The respective opening can have any desired contour and, in particular, be shaped as a circular bore or a slot. If the housing has multiple openings, all openings can preferably have the same geometry.

[0014] The respective opening can in particular be formed in a flow-calmed area of ​​the collection tank. In the flow-calmed area, the speed of the air flowing into the collection tank is low and the water has already been separated by gravity. In other words, the water in the flow-calmed area is already separated from the air flowing into the collection tank. As a result, when the air flowing into the collection tank flows back into the inlet channel, no water can be entrained and led into the inlet channel. The air flowing into the collection tank can therefore be fed back into the air laden with water droplets through the respective opening in a flow-optimized manner. The separated water remains in the collection tank and can be discharged through an outlet opening if necessary.

[0015] Preferably, at least one of the respective openings has a neck that extends into the collection container, in particular a neck that is at least substantially cylindrical. Preferably, the neck completely surrounds and / or runs around the respective opening. This advantageously prevents the water already separated in the collection container from being entrained or sucked (back) into the inlet channel through the respective opening.

[0016] In particular, the ratio between a flowable cross-section of the separating gap and a flowable cross-section of the outlet channel at the separating gap can be between 20% to 80% and 10% to 90%. In other words, the separating gap can be shaped such that the flowable cross-section of the separating gap amounts to 10% to 20% and the flowable cross-section of the outlet channel amounts to 90% to 80% of the total flowable cross-section. By definition, the total flowable cross-section is 100% and is composed of the flowable cross-section of the separating gap and the flowable cross-section of the outlet channel at the separating gap.

[0017] In one possible embodiment of the water separator, the inlet channel and the outlet channel can be aligned coaxially with one another and follow one another in the direction of air flow. The term "coaxial" refers to the longitudinal center axes of the respective channels. The separation gap is then formed around the outside of the outlet channel at a transition point formed between the inlet channel and the outlet channel. The housing of the water separator can, for example, have an inlet pipe and an outlet pipe that follow one another in the direction of air flow and are arranged coaxially with one another. The inlet pipe can have a widened portion facing the outlet pipe, and the outlet pipe can be arranged in some areas within the widened portion. In particular, the outlet pipe can be accommodated coaxially and at a distance from one another in the widened portion.The separating gap running around the outside of the outlet channel can then be formed between the outlet pipe and the widened portion of the inlet pipe. The separating gap can then be delimited radially outwards by the inlet pipe and radially inwards by the outlet pipe. Correspondingly, the collecting channel can also be delimited, at least in regions, radially outwards by the inlet pipe and radially inwards by the outlet pipe. The collecting container can also be formed on the outside of the outlet pipe. The water separator can also have a swirl generator. The respective opening can lead into the inlet channel downstream of the swirl generator. In other words, the opening can be arranged or shaped downstream of the swirl generator in the direction of air flow. The swirl generator can in particular be arranged and / or shaped between the inlet and the separating gap in the inlet channel. The swirl generator can thus be formed as a separate element and connected to the inlet channel orbe firmly connected to the intake pipe forming the intake port. Alternatively, the swirl generator can be molded together with the intake port or with the intake pipe forming the intake port, for example, using an injection molding process.

[0018] The swirl generator can have at least two spaced-apart vanes. Thus, the swirl generator can have exactly two or exactly three or exactly four or exactly five or more vanes. The respective vanes can be arranged at a distance from one another and distributed and in particular evenly distributed around the air flow direction or around the longitudinal center axis of the inlet duct or around the longitudinal center axis of the inlet pipe. The respective vane can follow a helical line or spiral in the air flow direction. In other words, the respective vane can represent a section of the helical line or spiral. The helical line or spiral can in particular be located on an outer wall forming the inlet duct or run along an outer wall forming the inlet duct. The respective opening can then be arranged downstream of the swirl generator and between the helical lines or spirals adjacent to the respective opening.In particular, the respective opening can be arranged at a distance from the screw lines or spirals adjacent to the respective opening.

[0019] As it flows through the water separator, the air laden with water droplets flows into the inlet and is set in rotation by the swirl generator. The separated water collects due to the centrifugal force between the respective blade and an outer wall forming the inlet channel. After each blade, the water then flows in a defined water stream along a screw line or spiral assigned to the respective blade along the outer wall of the inlet channel. Each opening is located between the respective adjacent screw lines or spirals and thus between the defined water streams assigned to the respective adjacent blades. Accordingly, the inflow of water into the respective opening can be advantageously prevented. This can advantageously prevent any harmful interaction between the water separated from the air and the air flow in the respective opening.

[0020] Preferably, first guides, in particular ribs, for guiding water to be separated, in particular water flowing along the wall, are arranged and / or formed on the inside of the inlet pipe forming the inlet channel.

[0021] Alternatively or additionally, second and / or third guides, in particular ribs, can be arranged and / or formed on the inside of the collecting container for guiding water (already) separated from the air.

[0022] Preferably, the first guides are located in the inlet pipe at least in regions between the swirl generator and / or the respective opening and the separation gap and / or collecting channel.

[0023] Alternatively or additionally, the second guides can be located in the collecting container, in particular directly opposite the separation gap and / or collecting channel.

[0024] Alternatively or additionally, the third guides in the collecting container can be located at least partially between the separation gap and / or collecting channel and the respective opening.

[0025] Preferably, a course of the first guides in the flow direction along the longitudinal center axis of the inlet pipe follows screw lines and / or spirals at least in some areas.

[0026] Alternatively or additionally, a course of the second guides in the flow direction along the longitudinal center axis of the inlet pipe can follow helical lines and / or spirals at least in some areas.

[0027] Alternatively or additionally, the third guides, viewed in the flow direction along the longitudinal center axis of the inlet pipe, can follow straight longitudinal lines at least in some areas. The first, second, or third guides can each have ribs or be designed as such, at least in some areas. In particular, the first, second, or third ribs are designed as helical lines and / or spirals and / or rectilinear, which is reflected in the respective profiles, as described above.

[0028] The first guides or ribs in the inlet pipe can be designed variably with regard to geometric dimensions such as rib height, their angle of incidence in relation to the longitudinal center axis of the inlet pipe and their distance from one another, or can be selected such that the course of the screw line and / or spiral-shaped first guides or ribs corresponds or geometrically matches the water flows forming in screw lines or spirals as a result of the swirl generator.

[0029] This makes it possible in a particularly advantageous manner for the water to be separated from the air, in particular water that flows along the wall, to be guided via the first guides or ribs to the separation gap without being carried along again by the air flow in the inlet channel.

[0030] From the separation gap, water already separated from the air can flow further into the collection tank via the collection channel.

[0031] The separated water can then be collected in the collecting container by the second guides or ribs, which are arranged and / or shaped in a screw line and / or spiral shape and are located, in particular directly opposite the separation gap and / or collecting channel, and guided to an outer wall of the collecting container following screw lines and / or spirals.

[0032] The geometric dimensions of the second guides or ribs and, accordingly, their course can be based on the first guides or ribs, or on other geometries of the water separator, in particular on the housing forming the collecting tank. The third guides or ribs can be connected, in particular directly, to the second guides or ribs in the collecting tank, viewed in the direction of flow along the longitudinal center axis of the inlet pipe.

[0033] The third guides or ribs can run in the collecting container in straight longitudinal lines, at least in some areas between the separating gap and / or collecting channel and the respective opening.

[0034] This makes it particularly advantageous to enable axial transport of the water separated from the air into the flow-calmed area of ​​the collection tank in order to then discharge the water in a targeted manner from the water separator.

[0035] In a possible alternative embodiment of the water separator, it can be provided that the inlet channel is aligned tangentially to the outlet channel. The separation gap can then be radially spaced and radially outward from the outlet channel and formed between an outer wall of the housing and a partition wall forming the inlet channel. The housing of the water separator can, for example, have an outlet pipe, and the outlet pipe can form the outlet channel. The inlet channel can be formed in regions by an inlet pipe and in regions by the outer wall of the housing and a partition wall. The inlet channel can be aligned tangentially or transversely to the outlet channel or the outlet pipe. The separation gap can be formed by the outer wall of the housing and the partition wall and divide the inlet channel into the outlet channel and the collecting channel.The partition wall can be arranged in the inlet channel such that the collecting channel is located radially outside the outlet channel. The collecting container can also be formed on the outside of the outlet channel or outlet pipe.

[0036] As it flows through the water separator, the water droplet-laden air flows into the inlet and through the inlet channel. At a transition point between the inlet channel and the outlet channel, the water droplet-laden air is deflected by the tangential arrangement of the inlet channel to the outlet channel. The separated water collects due to the centrifugal force on the outer wall of the housing forming the inlet channel and then flows through the radially outer separation gap into the collection channel. The air, free of water droplets, flows into the outlet channel and further out of the housing outlet.

[0037] The housing can further comprise a bulkhead located within the housing, wherein the bulkhead can fluidically separate the collecting channel and / or the collecting container from the inlet channel. In other words, the bulkhead can form the inlet channel and the collecting channel and / or the collecting container, at least in some regions. The bulkhead can be spiral-shaped and, in particular, arranged transversely to the outlet channel or transversely to the air flow direction in the outlet channel. The respective opening can be formed in the bulkhead and fluidically connect the collecting container to the inlet channel.

[0038] The invention also relates to a fuel cell system for a motor vehicle. The fuel cell system comprises a fuel cell. Furthermore, the fuel cell system has an air supply path and an exhaust air path. The exhaust air path leads from the fuel cell and is traversed by humid exhaust air—particularly containing water droplets. The air supply path leads to the fuel cell and is traversed by dry air drawn from the environment. The fuel cell system also has a humidifier for humidifying the air flowing in the air supply path with the exhaust air flowing in the exhaust air path. The humidifier can, for example, be a membrane humidifier with a membrane stack composed of several flexible membranes stacked at a distance from one another. The fuel cell system also has the water separator described above.The water separator can be positioned upstream of the humidifier in the supply air path, or between the fuel cell and the humidifier in the exhaust air path, or downstream of the humidifier in the exhaust air path. To avoid repetition, reference is made to the above explanations.

[0039] Further important features and advantages of the invention emerge from the dependent claims, the drawings, and the associated description of the figures with reference to the drawings. It is understood that the features mentioned above and those to be explained below can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the present invention.

[0040] Preferred embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description, wherein the same reference numerals refer to the same or similar or functionally identical components.

[0041] They show, schematically

[0042] Fig. 1 to 3 are sectional views of a water separator according to the invention in a first embodiment;

[0043] Fig. 4 is a sectional view of the water separator according to the invention in a second embodiment;

[0044] Fig. 5 is a partially transparent view of the water separator according to the invention in the second embodiment with a simulated air flow;

[0045] Fig. 6 is a sectional view of the water separator according to the invention in the second embodiment analogous to Fig. 4 with guides in the inlet pipe and collecting container;

[0046] Fig. 7 is an internal view of a housing part, in particular a part of the collecting container, of the water separator according to the invention in the second embodiment according to Fig. 6;

[0047] Fig. 8 to 10 show block diagrams of a fuel cell system according to the invention with the water separator according to the invention. Fig. 1 shows a sectional view of a water separator 1 according to the invention in a first embodiment. The water separator 1 comprises a housing 2, which is delimited on the outside by an outer wall 3. An inlet 4 and an outlet 5 are formed in the housing 2, and air laden with water droplets can flow through the housing 2 from the inlet 4 to the outlet 5. An inlet channel 6, an outlet channel 7, and a collecting channel 8 are also formed within the housing 2. In Fig. 1, the sectional plane is parallel to the air flow direction in the inlet channel 6 and perpendicular to the air flow direction in the outlet channel 7.

[0048] In addition, the housing 2 has a bulkhead 9 and a partition 10 arranged in the housing 2. The bulkhead 9 and the partition 10 delimit the inlet channel 6 from the collecting channel 8. A collecting container 11 is also formed in the housing 2 between the bulkhead 9 and the outer wall 3 of the housing 2. The inlet channel 6 is partially formed by an inlet pipe 6a and partially by the outer wall 3 of the housing 2, the bulkhead 9 and the partition 10. The outlet channel 7 is formed by an outlet pipe 7a that widens towards the outlet 5. Furthermore, a separating gap 12 is formed between the bulkhead 9, the partition 10 and the outer wall 3 of the housing 2.

[0049] The inlet channel 6 is provided for the air laden with water droplets and leads inside the housing 2 from the inlet 4 to the separation gap 12. The outlet channel 7 is provided for the air discharged of water droplets and leads inside the housing 2 from the inlet channel 6 past the separation gap 12 to the outlet 5. The collection channel 8 is provided for the water separated from the air and leads inside the housing 2 from the inlet channel 6 through the separation gap 12 into the collection container 11. The outlet channel 7 and the collection channel 8 are fluidically separated downstream of the separation gap 12.

[0050] The inlet channel 6 is aligned tangentially to the outlet channel 7 or the outlet pipe 7a, so that the air laden with water droplets is deflected as it passes from the inlet channel 6 into the outlet channel 7 and is subjected to centrifugal force. As a result, the water in the air is pushed radially outwards and forms a wall film on the outer wall 3 of the housing 2. The separation gap 12 is radially spaced apart from and formed radially outwardly of the outlet channel 7 or the outlet pipe 7a. The water exposed to centrifugal force thereby flows through the separation gap 12 into the collecting channel 8 and further into the collecting container 11. In the collecting container 11, the water settles downwards under the effect of gravity, and the air flowing in with the water calms down. The air flow is indicated by arrows in Fig. 1.

[0051] To prevent the buildup of a pressure cushion in the collecting tank 11 due to the air flowing in with the water, the housing 2 has an opening 13. The opening 13 is formed in the bulkhead 9 and connects the collecting tank 11 to the inlet channel 6. The air flowing into the collecting tank 11 can flow back into the inlet channel 6 through the opening 13, thereby preventing the buildup of the pressure cushion in the collecting tank 11. Accordingly, the pressure difference between the collecting channel 8 and the inlet channel 6 at the separating gap 12 can be reduced, thereby facilitating the flow of water into the collecting channel 12.

[0052] The opening 13 connects the inlet channel 6 to the collecting container 11 in a communicating or air-conducting manner in an axial direction relative to the outlet channel 7. The opening 13 has a central axis aligned parallel to the air flow direction in the outlet channel 7. The opening 13 arranged in the axial direction preferably has a flowable cross-section of less than 25%, in particular less than 15%, and greater than 7% of the flowable cross-section of the inlet channel 6.

[0053] Fig. 2 shows a further sectional view of the water separator 1 according to the invention. In Fig. 2, the sectional plane is perpendicular to the air flow direction in the inlet channel 6 and parallel to the air flow direction in the outlet channel 7. Fig. 2 shows the bulkhead 9 and a region of the inlet channel 6 formed by the bulkhead 9 and the outer wall 3 of the housing 2. Also visible is the collecting container n formed between the outer wall 3 of the housing 2 and the bulkhead 9.

[0054] Fig. 3 shows a further sectional view of the water separator 1 according to the invention. The sectional plane is aligned as in Fig. 2 and passes through the opening 13 in the bulkhead 9. As already explained above, the opening 13 fluidically connects the collecting container 11 and the inlet channel 6. The opening 13 is formed in a flow-calmed region of the collecting container 11. In the flow-calmed region of the collecting container 11, the water has already settled downwards under the effect of gravity, thus preventing the water from being entrained from the collecting container 11 into the inlet channel 6.

[0055] Fig. 4 shows a sectional view of the water separator 1 according to the invention in a second embodiment. The housing 2 of the water separator 1 is formed in two parts using an injection molding process. In the second embodiment, the inlet channel 6 is formed exclusively by the inlet pipe 6a and the outlet channel 7 is formed exclusively by the outlet pipe 7a. The inlet pipe 6a and the outlet pipe 7a are arranged coaxially and adjacent to one another or following one another in the direction of air flow. The inlet channel 6 or the inlet pipe 6a has a widened portion 6b facing the outlet channel 7 or the outlet pipe 7a, and the outlet pipe 7a is arranged in regions in the widened portion 6b. As a result, the separating gap 12 running around the outside of the outlet channel 7 or the outlet pipe 7a is formed.

[0056] A swirl generator 14 is also arranged or formed in the inlet channel 6 or the inlet pipe 6a. The swirl generator 14 comprises a plurality of vanes 15 that follow a helical line 16 or a spiral in the air flow direction or along a longitudinal center axis of the inlet channel 6 or the inlet pipe 6a. The vanes 15 are arranged circumferentially and spaced from one another with respect to the air flow direction or the longitudinal center axis of the inlet channel 6 or the inlet pipe 6a. The swirl generator 14 causes the air laden with water droplets to rotate, so that the water collects between the outer wall 3 of the housing 2 or the inlet pipe 6a and the respective vanes 15. This creates several defined water streams, which flow along the respective screw lines 16 or spirals to the separation gap 12 and through the collection channel 8 into the collection container 11. The air discharged from the water droplets, on the other hand, flows into the outlet channel 7 orthe outlet pipe 7a and further to the outlet 5. The air flow is indicated by arrows in Fig. 4.

[0057] The build-up of a pressure cushion in the collecting container 11 is prevented by the opening 13. The opening 13 is formed in the inlet pipe 6a and connects the collecting container 11 to the inlet channel 6. The opening 13 is arranged downstream of the swirl generator 14. The air flowing into the collecting container 11 can flow back into the inlet channel 6 through the opening 13. The opening 13 here connects the inlet channel 6 to the collecting container 11 in a radial direction with respect to the outlet channel 7 in a communicating or air-conducting manner. The opening 13 has a central axis that is oriented substantially or almost perpendicular to the air flow direction in the outlet channel 7. The opening 13 arranged in the radial direction preferably has a flow-through cross-section of less than 5%, in particular less than 2%, and greater than 0.1% of the flow-through cross-section of the inlet channel 6. The exact position orThe arrangement of the opening 13 is explained in more detail in Fig. 5.

[0058] Fig. 5 shows a partially transparent view of the water separator 1 according to the invention in the second embodiment with a simulated air flow. As can be seen particularly clearly in Fig. 5, several defined water flows form on the outer wall 3 of the housing 2 or on the inlet pipe 6a, which flow along the respective screw lines 16 or spirals to the separation gap 12. To prevent water from flowing into the opening 13, the opening 13 is located downstream of the swirl generator 14 and between the adjacent screw lines 16 or spirals. As a result, the opening 13 lies outside the defined water flows, and the inflow of water into the opening 13 can be prevented. Fig. 6 shows a sectional view of the water separator 1 according to the invention in the second embodiment, analogous to the illustration in Fig. 4.

[0059] Additionally, according to Fig. 6, the openings 13, which fluidically connect the collecting container 11 in the flow-calmed region to the inlet channel 6, have a neck 23, in particular an at least substantially cylindrical neck, projecting into the collecting container 11. The neck 23 completely surrounds or encircles or circumscribes the openings 13.

[0060] The neck 23 advantageously prevents water already separated in the collecting tank 11 from being entrained or sucked (back) into the inlet channel 6 through the respective opening 13. The separated water thus remains in the collecting tank 11.

[0061] It is conceivable that the respective opening 13 in the first embodiment of the water separator 1, as shown in Figs. 1 to 3, also has a corresponding neck 23 (not shown in Figs. 1 to 3).

[0062] Fig. 6 also shows first guides on the inside of the inlet pipe 6a, which are designed here as first ribs 24, for guiding the water to be separated from the air flow downstream of the swirl generator 14, in particular water along the wall.

[0063] The first ribs 24 are formed in a helical and / or spiral shape on the inside of the outer wall of the inlet pipe 6a and thus protrude into the inlet channel 6.

[0064] In addition, the first ribs 24 are formed relative to one another in the flow direction along the longitudinal center axis of the inlet pipe 6a in such a way that their snail-like and / or spiral-like course corresponds to or geometrically matches the water flows forming downstream as a result of the swirl generator 14 and thereby following snail lines and / or spirals 16, as described in Fig. 5.

[0065] This makes it particularly advantageous for the water flowing along the wall in the inlet pipe 6a as a result of the swirl generator 14 to be guided to the separation gap 12 via the first ribs 24 formed on the inside and following helical lines and / or spirals 16, without being entrained again by the air flow in the inlet channel 6. In Fig. 6, the helical lines and / or spirals 16, which the first ribs 24 follow in the inlet channel 6 and / or inlet pipe 6a, are shown in dashed lines.

[0066] It can also be clearly seen in Fig. 6 that the first ribs 24 in the inlet pipe 6a and / or inlet channel 6 are located at least in some areas between the swirl generator 14 and / or the respective openings 13 and the separation gap 12 and / or collecting channel 8.

[0067] From the separation gap 12, the water already separated from the air flows further via the collecting channel 8 into the collecting container 11.

[0068] The collecting container 11 shown in Fig. 6, as well as in Fig. 4, is pot-shaped or has a pot shape and is delimited to the outside by the outer wall 3 of the two-part housing 2 of the water separator 1. Furthermore, Fig. 6 shows second guides opposite the separation gap 12 and / or collecting channel 8 on the pot bottom 29 of the collecting container 11, which are designed here as second ribs 25.

[0069] The water already separated from the collecting channel 8 is first collected via the second ribs 25 formed in the pot bottom 29 and then guided radially outwards to the outer wall 3 of the collecting container 11 following screw lines and / or spirals 26 (see also Fig. 7).

[0070] Furthermore, third guides, which are designed here as third ribs 27, are shown in Fig. 6.

[0071] The third ribs 27 are formed in a straight line on the inside of the collecting container 11 and run at least partially following straight longitudinal lines 28 (shown in dashed lines in Fig. 6) between the separating gap 12 and / or collecting channel 8 and the openings 13.

[0072] The third ribs 27, as can be clearly seen in Fig. 6, adjoin the second ribs 25 when viewed in the flow direction along the longitudinal center axis of the inlet pipe 6a.

[0073] The third ribs 27 enable, in a particularly advantageous manner, an axial transport of the water separated from the air, following the straight longitudinal lines 28, into the flow-calmed area of ​​the collecting container 11 or the area of ​​the openings 13, in order to discharge the water from the water separator 1 in a targeted manner via an outlet (not shown here).

[0074] Fig. 7 shows, viewed in the flow direction along the longitudinal center axis of the inlet pipe 6a or along the longitudinal center axis of the outlet pipe 7a, an internal view of a part of the two-part housing 2 of the water separator 1 as shown in Fig. 6, wherein only the pot-shaped housing part is visible, which largely determines the collecting container 11.

[0075] In Fig. 7, the pot bottom 29 of the collecting container 11, viewed in the direction of flow, can also be seen particularly well as part of the outer wall 3 of the housing 2.

[0076] The second ribs 25, which are formed in the form of snail lines and / or spirals in the collecting container 11 and follow corresponding snail lines and / or spirals 26 (shown in dashed lines), as well as the third straight ribs 27, can be clearly seen.

[0077] It is also clearly visible that the second ribs 25 and the third ribs 27 are arranged alternately along the circumference of the collecting container 11 and the outer wall 3 of the housing 2, respectively. However, an arrangement in which the second and third ribs 25, 27 are arranged adjacent to one another along the circumference of the collecting container 11 is also conceivable.

[0078] Fig. 8 to Fig. 10 show block diagrams of a fuel cell system 17 according to the invention for a motor vehicle. The fuel cell system 17 comprises the water separator 1 according to the invention, an air filter 18, a turbocompressor 19 with a compressor 19a and a turbine 19b, an air cooler 20, a humidifier 21, and a fuel cell 22. The fuel cell 22 defines an air supply path ZL for the supply air and an exhaust air path AL for the exhaust air in the fuel cell system 17. The supply air path ZL leads from the outside or from other components of the motor vehicle through the air filter 18, the compressor 19a of the turbo compressor 19, the air cooler 20 and the humidifier 21 to the fuel cell 22. The exhaust air path AL leads from the fuel cell 22 through the humidifier 21 and the turbine 19b of the turbo compressor 19 to the outside or to other components of the motor vehicle.

[0079] Fig. 8 shows a first possible arrangement of the water separator 1 according to the invention in the fuel cell system 17. Here, the water separator 1 is fluidically connected upstream of the air filter 18 in the supply air path ZL.

[0080] Fig. 9 shows a second possible arrangement of the water separator 1 according to the invention in the fuel cell system 17. Here, the water separator 1 is fluidically connected in the exhaust air path AL between the fuel cell 22 and the humidifier 21, or fluidically connected upstream of the humidifier 21 in the exhaust air path AL, or fluidically connected downstream of the fuel cell 22 in the exhaust air path AL.

[0081] Fig. 10 shows a third possible arrangement of the water separator 1 according to the invention in the fuel cell system 17. Here, the water separator 1 is fluidically connected in the exhaust air path AL between the humidifier 21 and the turbine 19b of the turbocompressor 19, or fluidically connected upstream of the turbine 19b of the turbocompressor 19 in the exhaust air path AL, or fluidically connected downstream of the humidifier 21 in the exhaust air path AL.

[0082] *****

Claims

Claims 1. Water separator (1 ), in particular for a fuel cell system (17), - wherein the water separator (1) has a housing (2) through which air can flow, - wherein the housing (2) has an inlet (4) leading into the housing (2) and an outlet (5) leading out of the housing (2), - wherein the housing (2) has a collecting container (11) formed inside the housing (2) and a separating gap (12) formed inside the housing (2), - wherein the housing (2) has an inlet channel (6) for the air laden with water droplets and the inlet channel (6) leads inside the housing (2) from the inlet (4) to the separating gap (12), - wherein the housing (2) has an outlet channel (7) for the air discharged from water droplets, and the outlet channel (7) leads inside the housing (2) from the inlet channel (6) to the outlet (5), - wherein the housing (2) has a collecting channel (8) for the water separated from the air and the collecting channel (8) leads inside the housing (2) from the inlet channel (6) through the separation gap (12) into the collecting container (11), and - wherein the outlet channel (7) and the collecting channel (8) are fluidically separated downstream from the separating gap (12), characterized in that the collecting container (11) and the inlet channel (6) are fluidically connected to one another by means of at least one opening (13) formed upstream of the separating gap.

2. Water separator (1) according to claim 1, characterized in that the respective opening (13) is formed in a flow-calmed area of ​​the collecting container (11).

3. Water separator (1) according to claim 1 or 2, characterized in that at least one of the respective openings (13) has a neck (23) projecting into the collecting container (11), in particular an at least substantially cylindrical neck.

4. Water separator (1) according to claim 3, characterized in that the neck (23) completely surrounds and / or runs around the respective opening (13).

5. Water separator (1) according to one of the preceding claims, characterized in that a flowable cross section of the separation gap (12) and a flowable cross section of the outlet channel (7) have a ratio between 20% to 80% and 10% to 90%.

6. Water separator (1) according to one of the preceding claims, characterized in that - that the inlet channel (6) and the outlet channel (7) are aligned coaxially with each other and follow each other in the direction of air flow, and - that the separating gap (12) is formed continuously around the outside of the outlet channel (7) at a transition point formed between the inlet channel (6) and the outlet channel (7).

7. Water separator (1) according to claim 6, characterized in that the water separator (1) has a swirl generator (14) and the swirl generator (14) is arranged and / or shaped between the inlet (4) and the separation gap (12) in the inlet channel (6).

8. Water separator (1) according to claim 7, characterized in that that the respective opening (13) leads into the inlet channel (6) downstream of the swirl generator (14).

9. Water separator (1) according to claim 7 or 8, characterized in that - that the swirl generator (14) has at least two spaced-apart vanes (15) and the respective vane (15) follows a screw line (16) in the air flow direction, and - that the respective opening (13) is arranged downstream of the swirl generator (14) and between the two screw lines (16) adjacent to the respective opening (13).

10. Water separator (1) according to one of claims 6 to 9, characterized in that - that in an inlet pipe (6a) forming the inlet channel (6), first guides (24), in particular ribs, are arranged and / or formed on the inside for guiding water to be separated, in particular water flowing along the wall, and / or - that second and / or third guides (25, 27), in particular ribs, are arranged and / or formed on the inside of the collecting container (11) for guiding water separated from the air.

11. Water separator (1) according to claim 10, characterized in that - that the first guides (24) in the inlet pipe (6a) are located at least partially between the swirl generator (14) and / or the respective opening (13) and the separation gap (12) and / or collecting channel (8), and / or - that the second guides (25) are located in the collecting container (11), in particular directly opposite the separating gap (12) and / or collecting channel (8), and / or - that the third guides (27) in the collecting container (11) are located at least partially between the separating gap (12) and / or collecting channel (8) and the respective opening (13).

12. Water separator (1) according to claim 10 or 11, characterized in that - that a course of the first guides (24) in the flow direction along a longitudinal center axis of the inlet pipe (6a) follows at least partially helical lines and / or spirals (16), and / or - that a course of the second guides (25) in the flow direction along the longitudinal center axis of the inlet pipe (6a) follows at least partially helical lines and / or spirals (26), and / or - that a course of the third guides (27) in the flow direction along the longitudinal center axis of the inlet pipe (6a) follows at least partially straight longitudinal lines (28).

13. Water separator (1) according to one of claims 1 to 5, characterized in that - that the inlet channel (6) is aligned tangentially to the outlet channel (7), and - that the separating gap (12) is formed radially spaced and radially outwardly from the outlet channel (7) and between an outer wall (3) of the housing (2) and a separating wall (10) forming the inlet channel (6).

14. Water separator (1) according to claim 13, characterized in that - that the housing (2) has a bulkhead (9) located inside the housing (2), and - that the bulkhead (9) fluidically separates the collecting channel (8) and / or the collecting container (11) from the inlet channel (6), wherein the collecting container (11) is fluidically connected to the inlet channel (6) via the respective opening (13) formed in the bulkhead (9).

15. Fuel cell system (17) for a motor vehicle, - wherein the fuel cell system (17) comprises a fuel cell (22), - wherein the fuel cell system (17) has a supply air path (ZL) leading to the fuel cell (22) and through which supply air can flow, and an exhaust air path (AL) leading from the fuel cell (22) and through which exhaust air can flow, - wherein the fuel cell system (17) has a humidifier (21) for humidifying the supply air flowing in the supply air path (ZL) with the exhaust air flowing in the exhaust air path (AL), characterized in that - that the fuel cell system (17) has a water separator (1) according to one of the preceding claims, - wherein the water separator (1 ) is fluidically connected upstream of the humidifier (21 ) in the supply air path (ZL), and / or - wherein the water separator (1 ) is fluidically connected in the exhaust air path (AL) between the fuel cell (22) and the humidifier (21 ), and / or - wherein the water separator (1) is fluidically connected downstream of the humidifier (21) in the exhaust air path (AL).

Images