Mobile fuel cell system

Abstract

Mobile fuel cell system (1) comprising a fuel cell arrangement (2) and a recirculation arrangement (3), wherein - the recirculation arrangement (3) includes a tangential cyclone water separator (10) designed to separate a gas-water mixture into a gas fraction and a water fraction, - the tangential cyclone water separator (10) comprises a housing (17) defining a vortex chamber (16), a dip tube (18) projecting into the vortex chamber (16) and a dip tube bell (19), - a mixture inlet (11) is provided in the housing (17) through which the gas-water mixture can be supplied to the vortex chamber (16), - a water drain (13) is provided in the housing (17) through which the separated water fraction can be discharged from the vortex chamber (16), - the dip tube (18), through which the gas fraction can be discharged from the vortex chamber (16), widens towards its vortex chamber-side end into a funnel-shaped intake area (23), - the dip tube bell (19) surrounds the intake area (23) of the dip tube (18) in such a way that an annular space (24) is created between the dip tube bell (19) and the dip tube (18), which is open on its side facing the intake area (23) of the dip tube (18) towards the vortex chamber (16), and which is closed on its side facing away from the intake area (23) of the dip tube (18) towards the vortex chamber (16), - the immersion tube (18) has at least one passage in its area enclosed by the immersion tube bell (19) which fluidly connects the interior of the immersion tube (18) with the annular space (24), and - the open end face of the immersion tube bell (19) in the direction of the immersion tube axis (22) is essentially flush with the vortex chamber-side end face of the intake area (23) of the immersion tube (18).

Description

[0001] The present invention relates to a mobile fuel cell system.

[0002] Mobile fuel cell systems are used in a variety of designs in vehicles on water, in the air and on land to supply an electrical consumer with electrical energy.

[0003] For this purpose, a fuel carried in the vehicle, typically hydrogen, is supplied to a fuel cell array as needed, where it is converted into water and, if necessary, other products, releasing electrical energy in the process. The fuel is typically supplied to the fuel cell array as anode gas on the anode side, while the oxygen required for the reaction is supplied as cathode gas on the cathode side.

[0004] To prevent unused fuel from being released into the environment from the fuel cell assembly, mobile fuel cell systems often recirculate the anode exhaust gas. For this purpose, anode exhaust gas extracted from an (anode gas) outlet of the fuel cell assembly is mixed with fuel using a recirculation device and then fed back into the fuel cell assembly via an (anode gas) inlet. To enable this recirculation of the anode exhaust gas, recirculation devices typically include a jet pump (also called an ejector) or a blower.

[0005] The anode exhaust gas is typically a heterogeneous gas-water mixture in which liquid water is present as suspended particles in a gas fraction. The efficiency of the fuel cell arrangement is improved if not the entire gas-water mixture is recirculated, but only its gas fraction. For this purpose, recirculation systems typically include a water separator, which separates the gas-water mixture extracted from the anode gas outlet into a gas fraction and a water fraction. The gas fraction is then mixed with fuel again and fed back into the anode gas inlet, while the separated water fraction is discharged from the water separator via a water outlet.

[0006] Such water separators are typically designed as mass force separators, based on the principle that the water particles carried in the gas can no longer follow the flow of the gas due to the mass forces acting upon them and are separated on internal components or walls of the water separator.

[0007] In so-called cyclone or centrifugal water separators, the gas-water mixture entering the water separator is set into a rotational motion or a rotational flow due to its speed, so that the water particles suspended in the air are (at least partially) separated as a result of the centrifugal force acting on them.

[0008] A typical cyclone water separator features a (conical or cylindrical) vortex chamber into which a dip tube extends from above. The gas-water mixture flows into the vortex chamber at its flow velocity via an inlet. If the gas-water mixture enters the vortex chamber tangentially with respect to its axis, it is called a tangential cyclone water separator. The gas-water mixture flowing into the vortex chamber at its velocity is deflected by the chamber wall and thus set into rotation. Due to the centrifugal force acting upon them, the suspended water particles are (at least partially) separated at the wall of the vortex chamber, flow downwards under the influence of gravity, and collect as liquid water in the lower part of the vortex chamber. From there, the water can be discharged from the vortex chamber via an outlet.

[0009] A variety of different tangential cyclone water separators are known from the prior art. These are typically highly adapted to the respective application or operating conditions as well as the composition of the gas-water mixture.

[0010] The use of a mobile fuel cell system in a moving vehicle places very specific demands on the system and its components. The water separator, in particular, must reliably separate the gas fraction from the water fraction in various driving situations, such as changing centrifugal forces when cornering, accelerating and braking, experiencing vibrations, driving on inclines, and under various dynamically changing load conditions across a wide temperature range, while also being designed to be very compact due to space constraints.

[0011] From the extensive body of prior art, reference is made to publication JP 2016072183 A as an example of a mobile fuel cell system with a recirculation arrangement incorporating a water separator. Publication DE 1 769 579 A describes a cyclone for separating gases from liquid-gas mixtures with collar- or baffle-shaped covers that surround a gas outlet projecting into a separation vessel.

[0012] The present invention is based on the objective of providing a mobile fuel cell system of the type described above, which is characterized by improved practicality, in particular with regard to the above-mentioned requirements placed on the water separator by mobile use.

[0013] This problem is solved by the mobile fuel cell system according to claim 1. The mobile fuel cell system according to the invention comprises a fuel cell arrangement and a recirculation arrangement, wherein - the recirculation arrangement includes a tangential cyclone water separator designed to separate a gas-water mixture into a gas fraction and a water fraction, - the tangential cyclone water separator comprises a housing defining a (especially cylindrical) vortex chamber, a dip tube projecting (from above) into the vortex chamber and a dip tube bell, - a mixture inlet is provided in the housing, through which the gas-water mixture can be supplied to the vortex chamber (laterally tangentially), - a water drain is provided in the housing, through which the separated water fraction can be discharged from the vortex chamber, - the dip tube, through which the gas fraction can be discharged from the vortex chamber, widens towards its vortex chamber-side end into a funnel-shaped intake area, - the dip tube bell surrounds the intake area of ​​the dip tube in such a way that an annular space opens between the dip tube bell and the dip tube, which is open towards the vortex chamber on its side facing the intake area of ​​the dip tube, and which is closed towards the vortex chamber on its side facing away from the intake area of ​​the dip tube, - the immersion tube has at least one passage in its area enclosed by the immersion tube bell, which fluidly connects the interior of the immersion tube to the annular space, and - the open end face of the immersion tube bell (19) in the direction of the immersion tube axis (22) is essentially flush with the vortex chamber-side end face of the intake area (23) of the immersion tube (18).

[0014] The invention is based primarily on the realization that a unique combination of advantages can be achieved through the synergistic interaction of the features according to the invention.

[0015] The inventors recognized that liquid water precipitates on the inner wall of the immersion tube during normal operation. This water is then induced by the upward gas flow within the immersion tube and transported upwards along the inner wall, or "creeps" upwards. This can lead to the undesirable re-entry of the water creeping upwards along the inner wall, along with the recirculated gas fraction, back into the fuel cell assembly.

[0016] However, the interaction of the features according to the invention can advantageously and effectively prevent this, thus improving the effectiveness of the water separator and the efficiency of the entire fuel cell system: This is because the water creeping upwards is drained from the interior of the dip tube into the annular space between the dip tube and the dip tube bell via at least one passage in the dip tube, and thus removed from the dip tube, so that it is not returned to the fuel cell assembly in an undesirable way.

[0017] The funnel-shaped, downward-expanding intake area of ​​the dip tube facilitates the separation of liquid water in this (lower) section of the dip tube, as the larger cross-section results in lower flow velocities. The water is thus separated primarily in the intake area and therefore at the lower end of the dip tube. This means the water has to travel a longer distance upwards before it can exit the water separator via the dip tube, thus advantageously providing a larger section of the dip tube for the discharge of water into the annular space.

[0018] The immersion tube bell prevents the liquid water drained from the immersion tube through the openings from being carried away and mixed again by the gas-water mixture rotating in the vortex chamber. This is because the gas flow velocities in the annular space enclosed by the immersion tube bell are very low, so the water is not carried away by the gas flow again, but instead flows downwards by gravity along the outer wall of the immersion tube or the inner wall of the immersion tube bell. Reaching the lower edge of the immersion tube or the immersion tube bell, the water then drips down and collects in a water collection volume in the lower part of the vortex chamber. From there, it is discharged from the water separator via the water outlet, particularly when a certain fill level is reached.

[0019] The advantages of the mobile fuel cell system according to the invention are particularly evident when, in connection with its use in a vehicle, vibrations and sudden changes in movement cause the water already separated and collected in the water collection volume to spray through the entire vortex chamber and (also) wet the inner wall of the immersion tube.

[0020] The following section will discuss individual features of the hydrogen fuel cell system according to the invention in more detail.

[0021] By means of the recirculation arrangement, the gas fraction of the gas-water mixture can be recirculated from an outlet of the fuel cell arrangement to an inlet of the fuel cell arrangement, while the water fraction can be separated from the gas-water mixture and discharged via the water outlet in the housing of the water separator.

[0022] The axes of the vortex chamber and the immersion tube (immersion tube axis) are, in the intended installation position of the water separator, essentially aligned along the force of gravity and vertically, so that the separated water can be drawn by gravity into a water collection volume located below and collected there. Position designations used, such as top, bottom, side, refer to the intended installation position.

[0023] The dip tube widens towards its vortex chamber end, i.e., its lower end, into the funnel-shaped intake area. The term "funnel-shaped" here includes, in particular, frustoconical and trumpet-shaped shapes. The dip tube has a wall consisting of an inner and an outer wall. The inner wall of the dip tube defines the interior space of the dip tube.

[0024] Through the at least one passage, the interior of the dip tube is fluidly connected to the annular space that extends between the dip tube and the dip tube bell, so that liquid water can be drained from the interior of the dip tube into the annular space via the at least one passage.

[0025] The dip tube bell surrounds the intake area of ​​the dip tube. This wording should be understood to mean that the dip tube bell surrounds the intake area of ​​the dip tube laterally (i.e., radially relative to the dip tube axis) and upwards, but does not cover the intake area downwards (i.e., in the extension of the dip tube axis). The flow of the gas fraction from below into the intake area is therefore not obstructed by the dip tube bell.

[0026] According to a preferred embodiment of the invention, - which has at least one opening designed as at least one penetration in the wall of the immersion tube, - which is realized at least one passage through water-permeable pores in the wall of the immersion tube, and / or - which has at least one opening in the funnel-shaped intake area of ​​the dip tube.

[0027] The at least one passage can be configured as at least one opening in the wall of the immersion tube, and this opening can have various shapes (e.g., round, oval, slit-shaped, spiral, rectangular, square). Although obvious to those skilled in the art, it should be explicitly noted here that the opening on the end face of the immersion tube facing the vortex chamber is not an opening in the wall of the immersion tube in the present sense.

[0028] Alternatively, the at least one passage can be achieved through water-permeable pores in the wall of the immersion tube by making at least one section of the immersion tube a water-permeable fabric, knitted material, or nonwoven, allowing water to pass through the water-permeable pores of the fabric, knitted material, or nonwoven from the interior of the immersion tube into the annular space. This water-permeable section of the immersion tube can have various shapes (e.g., round, oval, slit-shaped, rectangular, square, ring-shaped, spiral). It is also conceivable that the entire immersion tube could be made of such a fabric, knitted material, or nonwoven.

[0029] If the at least one passage is located in the funnel-shaped intake area, the water creeping upwards on the inner wall of the dip tube can already be discharged through the at least one passage before it reaches the narrower, higher-lying (cylindrical) area of ​​the dip tube, where the gas flow velocities are greater and the risk increases that the water creeping on the inner wall will be carried along by the gas fraction.

[0030] It is particularly advantageous that the funnel-shaped intake area of ​​the dip tube widens in a frustoconical or trumpet shape towards its vortex chamber-side end.

[0031] To further increase the amount of water discharged, it may be possible to provide that - the immersion tube has at least one groove on its inner wall, and - which has at least one passage in which at least one channel is arranged.

[0032] The at least one channel allows water that has collected on the inner wall to be collected and directed to the at least one opening. This prevents (at least some of) the water from creeping further up the dip tube past the openings. A channel is defined as an elongated depression on the inner wall of the dip tube.

[0033] Especially preferred - the immersion tube has at least two (especially slot-shaped) openings in its area enclosed by the immersion tube bell, and - the at least two (especially slot-shaped) passages are arranged along an imaginary circle extending on the surface of the immersion tube and are separated by webs.

[0034] In this way, a particularly large proportion of the water that has accumulated on the inner wall of the dip tube can be drained away through the openings. The term "imaginary circle" is intended to include not only (ideal) circles, but also ellipses and ovals.

[0035] It is particularly preferred that - which have at least two openings, each slit-shaped, and - the slot-shaped openings extend in such a way that they are each inclined in their longitudinal extension against the direction of water ascent.

[0036] The upward creep of the water along the inner wall of the dip tube—and thus the direction of water ascent—is induced by the flow of the gas fraction rising through the dip tube. Since the gas-water mixture in the vortex chamber is set into a (downward) rotational flow, the gas fraction flows through the interior of the dip tube in a rotationally aligned, upward-directed flow. As a result, the upward creep of the water along the inner wall of the dip tube—and thus the direction of water ascent—follows a spiral trajectory oriented in the same direction of rotation.

[0037] If the slot-shaped openings are inclined in their longitudinal extent (according to this preferred embodiment) against the direction of water ascent, the extent of the openings perpendicular to the direction of water ascent is increased in this way, so that more water can be discharged through the openings and less water can creep past the openings.

[0038] According to another advantageous embodiment of the invention - the at least two (especially slot-shaped) openings cover a larger part of the imaginary circle than the webs, and - In particular, the slot-shaped openings extend along the imaginary circle.

[0039] The openings therefore extend along an imaginary circle around the dip tube. In this way, a particularly large portion of the upward-creeping water can be drained away.

[0040] Particularly advantageously, the openings can be arranged along several imaginary circles, with the individual circles lying in parallel circular planes and thus being offset one behind the other, especially in the direction of the immersion tube axis. This ensures that water passing through the openings of a first circle is discharged through an opening of the subsequent circles, thereby increasing the proportion of water discharged from the interior of the immersion tube.

[0041] Another advantageous embodiment of the invention provides that - the immersion tube has at least two (especially slot-shaped) openings in its area enclosed by the immersion tube bell, and - the at least two (especially slot-shaped) passages are arranged along an imaginary helical line or spiral enclosing the immersion tube and are separated by webs, and in particular - the at least two (especially slot-shaped) openings cover a larger part of the imaginary helix or spiral than the webs, - the slot-shaped openings extend along the helix or spiral, and / or - the imaginary helix or spiral winds upwards in the opposite direction to the rotational flow of the gas-water mixture flowing into the vortex chamber.

[0042] In this way, a very large part of the water creeping up the inner wall of the dip tube can be drained out of the dip tube.

[0043] Similarly advantageous results can be achieved if, alternatively, the immersion tube is provided to have a slot-shaped opening in its area enclosed by the immersion tube bell, which extends along an imaginary circle arranged on the surface of the immersion tube and is bounded by a web, and optionally the slot-shaped opening covers a larger part of the imaginary circle than the web.

[0044] Alternatively, it may also be provided that - the immersion tube has a slot-shaped opening in its area enclosed by the immersion tube bell, which extends along an imaginary helix or spiral enclosing the immersion tube, and in particular - the slot-shaped opening covers an angular range of more than 90°, in particular more than 180°, and / or - the imaginary helix or spiral winds upwards in the opposite direction to the rotational flow of the gas-water mixture flowing into the vortex chamber.

[0045] According to another preferred embodiment of the invention, the tangential cyclone water separator has a guide plate, - which, starting in the area of ​​the mixture inlet, extends spirally between the immersion tube bell and the housing, partially around the immersion tube bell, - so that an inner flow channel extends between the immersion tube bell and an inner side of the guide plate and an outer flow channel extends between an outer side of the guide plate and the housing, and in particular the gas-water mixture flowing into the vortex chamber through the mixture inlet can be divided by the guide plate into the inner flow channel and the outer flow channel.

[0046] The guide plate allows the gas-water mixture flowing into the vortex chamber via the mixture inlet to be divided between the inner and outer flow channels. The statement that the guide plate extends partially around the immersion tube bell between the immersion tube bell and the housing indicates that the guide plate extends around the immersion tube bell at an angle of at least 90°.

[0047] The baffle plate and the resulting division of the gas-water mixture into the inner and outer flow channels provide more wall surface area on which the water fraction of the gas-water mixture can separate. This allows more water to be separated from the gas-water mixture, thus advantageously increasing the effectiveness of the water separator.

[0048] Furthermore, it may be advantageously provided that - the dip tube has an inner edge radius on its inner wall at its end face projecting into the vortex chamber and optionally an outer edge radius on its outer wall, wherein the inner edge radius is larger than the outer edge radius, and / or the inner edge radius is larger than the greatest wall thickness of the dip tube in the intake area, and / or the dip tube has a drip edge on its outer wall at its end face projecting into the vortex chamber, and / or - the immersion tube bell has an inner edge radius on its inner wall at its end face projecting into the vortex chamber and optionally has an outer edge radius on its outer wall, wherein the inner edge radius is larger than the outer edge radius, and / or the inner edge radius is larger than the greatest wall thickness of the immersion tube bell, and / or the immersion tube bell has a drip edge on its outer wall at its end face projecting into the vortex chamber, - the guide plate has an inner edge radius on its inner wall at its end face projecting into the vortex chamber and optionally has an outer edge radius on its outer wall, wherein the inner edge radius is larger than the outer edge radius, and / or the inner edge radius is larger than the greatest wall thickness of the guide plate.

[0049] By providing a large outer edge radius on the inner wall of the respective component (dip tube, dip tube bell, guide plate), the formation of water droplets can be prevented. This advantageously reduces the probability of water droplets detaching in the immediate vicinity of the dip tube, being carried along by the gas fraction, and being discharged from the water separator via the dip tube.

[0050] According to another advantageous embodiment of the mobile fuel cell system according to the invention, it is provided that - the tangential cyclone water separator includes a baffle plate which is arranged in the vortex chamber between the mixture inlet and the water outlet and limits a water collection volume extending between the water outlet and the baffle plate, - the separating plate is curved towards the intake area of ​​the dip tube, and - the partition plate has several partition plate openings.

[0051] The baffle plate prevents water in the water collection volume from splashing unchecked through the vortex chamber and entering the dip tube when triggered by vibrations, acceleration, braking, or cornering. The curvature of the baffle plate (towards the dip tube's intake area) contributes to reducing the flow resistance of the gas fraction entering the intake area.

[0052] Particularly preferred are the openings in the separating plates designed in a slotted shape and arranged in a star shape.

[0053] It is provided in a particularly advantageous way that - the partition openings are arranged at the edges outside of a partition central area, and - the position and extent of the partition plate's central area is determined by the projection of the intake area onto the partition plate in the direction of the immersion tube axis.

[0054] Because the area of ​​the partition plate closest to the intake area of ​​the dip tube, the partition plate middle area, has no partition plate openings and is thus shielded from the water collection volume to a certain extent, it can be prevented even more effectively that water in the water collection volume splashes into the intake area of ​​the dip tube triggered by vibrations, acceleration, braking or cornering.

[0055] Particularly low pressure losses in the water separator can be achieved if - the minimum internal cross-sectional area of ​​the immersion tube divided by the minimum internal cross-sectional area of ​​the mixture inlet yields a value of 0.5 to 2, in particular 0.75 to 1.5, in particular 0.9 to 1.1, in particular 1, and / or - the open end-face outer cross-sectional area of ​​the immersion tube bell divided by the maximum outer cross-sectional area of ​​the intake area of ​​the immersion tube yields a value of 1 to 3, in particular of 1 to 2.5, in particular of 1.5 to 2.5.

[0056] The minimum internal cross-sectional area of ​​the immersion tube or mixture inlet is the minimum clear cross-sectional area of ​​the respective component. For a tube with a circular cross-section, the inner diameter of the tube is used to determine the internal cross-sectional area.

[0057] The maximum external cross-sectional area of ​​the immersion tube bell or the intake area is the maximum cross-sectional area that results for the respective component, taking into account the respective wall thickness. If the immersion tube bell or the intake area has a circular cross-section, the respective outer diameter is used to determine the respective external cross-sectional area.

[0058] In the invention, it is further beneficial to the reduction of pressure loss in the water separator that the open end face of the dip tube bell is essentially flush with the vortex chamber-side end face of the intake area of ​​the dip tube in the direction of the dip tube axis.

[0059] In this context, the phrase "essentially" means that the offset in the direction of the immersion tube axis between the open end face of the immersion tube bell and the vortex chamber-side end face of the intake area of ​​the immersion tube is less than the minimum inner diameter of the immersion tube.

[0060] Some exemplary embodiments of the invention are explained in more detail below with reference to the drawing. This shows Fig. 1 a schematic representation of a mobile fuel cell system according to the invention, Fig. 2 a side sectional view of the tangential cyclone water separator of the mobile fuel cell system according to Fig. 1, Fig. 3A a cross-section of the tangential cyclone water separator viewed along section AA according to Fig. 2, Fig. 3B a cross-section of the tangential cyclone water separator viewed along section BB according to Fig. 2, Fig. 4 the immersion tube of the tangential cyclone water separator according to the Fig. 2 and Fig. 3 in a perspective oblique view, Fig. 5 to 12B each a dip tube of a tangential cyclone water separator of another mobile fuel cell system according to the invention.

[0061] Fig. Figure 1 shows a schematic representation of a mobile fuel cell system 1 according to the invention, comprising a fuel cell arrangement 2 and a recirculation arrangement 3.

[0062] Hydrogen can be supplied to the mobile fuel cell system 1 via a hydrogen tank arrangement 4 and a valve unit 5 via the hydrogen inlet 6 and converted to water with the release of electrical energy.

[0063] By means of the recirculation arrangement 3, anode exhaust gas taken from an anode gas outlet 7 of the fuel cell arrangement 2 can be mixed with hydrogen from the hydrogen inlet 6 and then fed back to the fuel cell arrangement 2 via an anode gas inlet 8 of the fuel cell arrangement 2. For this purpose, the recirculation arrangement 3 has a jet pump 9.

[0064] To separate the water fraction of the anode exhaust gas (as far as possible) before it enters the jet pump 9, the recirculation arrangement 3 further includes a tangential cyclone water separator 10. The tangential cyclone water separator 10 separates the anode exhaust gas, also known as a gas-water mixture, into a gas fraction and a water fraction. The gas-water mixture enters the water separator 10 via a mixture inlet 11, the gas fraction exits the water separator 10 via a gas outlet 12, and the water fraction exits the water separator 10 via a water outlet 13.

[0065] Oxygen can be supplied to the fuel cell arrangement 2 via a cathode gas inlet 14, and reaction products can be removed via a cathode gas outlet 15.

[0066] Constructive details of the tangential cyclone water separator 10 according to Fig. 1. The following refers to the Fig. 2, Fig. 3 to Fig. 4 explained in more detail. Position designations used, such as top, bottom, side, clockwise and counterclockwise, refer to the installation position of the associated component as shown in the respective figure.

[0067] The tangential cyclone water separator 10 comprises a housing 17 bounding a cylindrical vortex chamber 16, a dip tube 18 projecting from above into the vortex chamber 16, a dip tube bell 19, a guide plate 20 and a separating plate 21.

[0068] The mixture inlet 11 is provided laterally in the housing 17, through which the gas-water mixture (i.e., the anode exhaust gas) can be supplied laterally and tangentially to the vortex chamber 16. The separated water fraction can be discharged from the vortex chamber 16 via the water outlet 13 provided at the bottom of the housing 17.

[0069] The separated gas fraction can be discharged upwards via the gas outlet 12 through the dip tube 18. The dip tube 18 extends along its axis 22 and widens downwards towards its vortex chamber end, i.e., into a funnel-shaped, frustoconical intake area 23.

[0070] The minimum internal cross-sectional area of ​​the immersion tube 18a is exactly the same as the minimum internal cross-sectional area of ​​the mixture inlet 11a. Therefore, dividing these two values ​​results in the value 1.

[0071] The immersion tube bell 19 surrounds the immersion tube 18 in such a way that an annular space 24 is created between the immersion tube bell 19 and the immersion tube 18, which is open on its side facing the intake area of ​​the immersion tube (i.e. downwards) towards the vortex chamber 16, and which is closed on its side facing away from the intake area of ​​the immersion tube (i.e. upwards) towards the vortex chamber 16.

[0072] In the area enclosed by the immersion tube bell 19, the immersion tube 18 has two openings 25 in the intake area 23, which connect the interior of the immersion tube 18 with the annular space 24. The slot-shaped openings 25 are separated from each other by webs 26 and extend along an imaginary circle 27 on the surface of the immersion tube 18 (see Fig. 3B and Fig. 4) The two passages 25 cover a larger part of the imaginary circle 27 than the bridges 26.

[0073] The open end face of the immersion tube bell 19a divided by the maximum outer cross-sectional area of ​​the intake region 23a of the immersion tube yields a value of approximately 1.8. The open end face of the immersion tube bell 19 is flush with the vortex chamber-side end face of the intake region 23 of the immersion tube 18 in the direction of the immersion tube axis 22.

[0074] The guide plate 20 extends spirally around the immersion tube bell 19, starting in the area of ​​the mixture inlet 11, between the immersion tube bell 19 and the housing 17 at an angle w1. An inner flow channel 28i extends between the immersion tube bell 19 and an inner surface 20i of the guide plate 20 (facing the immersion tube 18). An outer flow channel 28a extends between an outer surface 20a of the guide plate 20 (facing away from the immersion tube 18) and the housing 17. The gas-water mixture flowing into the vortex chamber 16 through the mixture inlet 11 is divided by the guide plate 20 into the inner flow channel 28i and the outer flow channel 28a.

[0075] According to Fig. 3A, i.e., viewed from above at section AA, the gas-water mixture is set into a counterclockwise rotating flow 29. If, however, section BB is viewed according to Fig. Viewed from below, 3B shows the same rotational flow 29 oriented clockwise.

[0076] The immersion tube 18, the immersion tube bell 19, and the guide plate 20 each have rounded inner edges on the end face projecting into the vortex chamber 16. The inner radii of the vortex chamber-side end faces of the immersion tube 18, the immersion tube bell 19, and the guide plate 20 are each larger than the (maximum) wall thickness of the respective component.

[0077] The baffle plate 21 is arranged between the mixture inlet 11 and the water outlet 13 and defines a water collection volume 30 extending between the water outlet 13 and the baffle plate 21. The baffle plate 21 is curved towards the intake area 23 of the immersion tube 18 and has several baffle plate openings 32 at its edges outside a central baffle plate area 31, through which water can enter the water collection volume 30. The position and extent of the central baffle plate area are determined by the projection of the intake area 23 onto the baffle plate 21 in the direction of the immersion tube axis 22.

[0078] The Fig. Figures 5 to 12B each show a dip tube 18 of a tangential cyclone water separator 10 of another mobile fuel cell system 1 according to the invention. The dip tubes 18 shown differ in type, shape, number and arrangement of the passages.

[0079] For the immersion tube 18 according to Fig. 5. Do the two openings match the openings in shape and position according to... Fig. 4 agree, however the passages are according to Fig. 5 each as a metallic fabric 33 (and not as in Fig. 4 as a breakthrough 25).

[0080] According to Fig. Six slot-shaped openings 25 of the immersion tube 18 are arranged along two imaginary circles 27, the two circles 27 lying in parallel circular planes and offset one behind the other in the direction of the immersion tube axis 22. The openings 25 are separated from each other by webs 26.

[0081] For the immersion tube 18 according to Fig. 7 the circular openings 25 are arranged along an imaginary circle 27 extending on the surface of the immersion tube 18 and are separated from each other by webs 26.

[0082] The Fig. 8A and Fig. Figure 8B shows a dip tube 18 of another mobile fuel cell system 1 according to the invention in a perspective oblique view ( Fig. 8A) or in a perspective cross-sectional view ( Fig. 8B). The slot-shaped openings 25 are arranged along an imaginary circle 27 extending on the surface of the immersion tube 18 and are separated by webs 26. The slot-shaped openings 25 are each inclined in their longitudinal extent 25L opposite the direction of water ascent 34 (induced by the rotational flow 29 of the water-gas mixture), i.e., the direction of water creeping upwards on the inner wall of the immersion tube 18.

[0083] The immersion tube 18 according to the Fig. 9 differs from the immersion tube 18 according to Fig. 8 in particular by the fact that the slot-shaped openings 25 are arranged along an imaginary spiral 35 enclosing the immersion tube 18, wherein the imaginary spiral 35 winds upwards in the opposite direction to the rotational flow 29 of the gas-water mixture flowing into the vortex chamber (at the immersion tube 18).

[0084] The immersion tube 18 according to Fig. 10 has a (single) slot-shaped passage 25 which extends along an imaginary spiral 35 enclosing the immersion tube 18 and covers an angular range of more than 180°.

[0085] Fig. Figure 11 shows another immersion tube 18 in a perspective cross-sectional view. The immersion tube 18 has grooves 36 (i.e., elongated depressions) on its inner wall, in each of which a circular opening 25 is arranged.

[0086] The Fig. 12A and Fig. Figure 12B shows another immersion tube 18 in a perspective oblique view ( Fig. 12A) and a top view ( Fig. 12B). This immersion tube 18 has a (single) slot-shaped opening 25 extending along an imaginary circle 27 arranged on the surface of the immersion tube and bounded by a (single) web 26, the slot-shaped opening 25 covering a larger part of the imaginary circle 27 than the web 26. Reference symbol list 1 Mobile fuel cell system 2 Fuel cell arrangement 3 Recirculation arrangement 4 Hydrogen tank arrangement 5 valve unit 6 Hydrogen inlet 7 Anode gas outlet 8 Anode gas inlet 9 jet pump 10 tangential cyclone water separators 11 Mixture feed 11a Minimum internal cross-sectional area of ​​the mixture inlet 12 Gas outlet 13 Water drain 14 Cathode gas inlet 15 Cathode gas outlet 16th cervical chamber 17 cases 18 dip tube 18a Minimum internal cross-sectional area of ​​the immersion tube 19 Immersion tube bell outer cross-sectional area 19a of the diving tube bell 20 guide plates 20i Inside of the guide plate 20a Outer side of the guide plate 21 Dividing plate 22 Immersion tube axle 23 Intake area 23a Maximum external cross-sectional area of ​​the intake area 24 ring space 25 Breakthrough 25L Longitudinal extent of the breakthrough 26 Bridge 27 Imaginary Circle 28i inner flow channel 28a outer flow channel 29 Rotational flow 30 water collection volume 31 Dividing plate center area 32 partition openings 33 tissues 34 Direction of water ascent 35 Imaginary Spiral 36 gutter

Claims

[1] Mobile fuel cell system (1) comprising a fuel cell arrangement (2) and a recirculation arrangement (3), wherein - the recirculation arrangement (3) includes a tangential cyclone water separator (10) designed to separate a gas-water mixture into a gas fraction and a water fraction, - the tangential cyclone water separator (10) comprises a housing (17) defining a vortex chamber (16), a dip tube (18) projecting into the vortex chamber (16) and a dip tube bell (19), - a mixture inlet (11) is provided in the housing (17) through which the gas-water mixture can be supplied to the vortex chamber (16), - a water drain (13) is provided in the housing (17) through which the separated water fraction can be discharged from the vortex chamber (16), - the dip tube (18), through which the gas fraction can be discharged from the vortex chamber (16), widens towards its vortex chamber-side end into a funnel-shaped intake area (23), - the dip tube bell (19) surrounds the intake area (23) of the dip tube (18) in such a way that an annular space (24) is created between the dip tube bell (19) and the dip tube (18), which is open on its side facing the intake area (23) of the dip tube (18) towards the vortex chamber (16), and which is closed on its side facing away from the intake area (23) of the dip tube (18) towards the vortex chamber (16), - the immersion tube (18) has at least one passage in its area enclosed by the immersion tube bell (19) which fluidly connects the interior of the immersion tube (18) with the annular space (24), and - the open end face of the immersion tube bell (19) in the direction of the immersion tube axis (22) is essentially flush with the vortex chamber-side end face of the intake area (23) of the immersion tube (18). [2] Mobile fuel cell system (1) according to claim 1, wherein - which at least one passage is designed as at least one opening (25) in the wall of the immersion tube, - which at least one passage is realized through water-permeable pores in the wall of the immersion tube (18), and / or - which has at least one passage in the funnel-shaped intake area (23) of the immersion tube (18). [3] Mobile fuel cell system (1) according to one of the preceding claims, wherein the funnel-shaped intake area (23) of the immersion tube (18) widens towards its vortex chamber side end in a frustoconical or trumpet-shaped manner. [4] Mobile fuel cell system (1) according to any one of the preceding claims, wherein - the immersion tube (18) has at least one groove (36) on its inner wall, and - which has at least one passage in the at least one channel (36). [5] Mobile fuel cell system (1) according to any one of the preceding claims, wherein - the immersion tube (18) has at least two, in particular slot-shaped, openings in its area encompassed by the immersion tube bell (19), and - the at least two, in particular slot-shaped, passages are arranged along an imaginary circle (27) extending on the surface of the immersion tube (18) and are separated by webs (26). [6] Mobile fuel cell system (1) according to claim 5, wherein - which have at least two openings, each slit-shaped, and - the slot-shaped openings extend in such a way that they are each inclined in their longitudinal extension opposite to the direction of water ascent (34). [7] Mobile fuel cell system (1) according to claim 5, wherein - the at least two, in particular slot-shaped, openings cover a larger part of the imaginary circle (27) than the webs (26), and - in particular the slot-shaped openings each extend along the imaginary circle (27). [8] Mobile fuel cell system (1) according to any one of claims 1 to 4, wherein - the immersion tube (18) has at least two, in particular slot-shaped, openings in its area enclosed by the immersion tube bell (19), and - the at least two, in particular slot-shaped, passages are arranged along an imaginary helix or spiral (35) enclosing the immersion tube (18) and are separated by webs (26), and in particular - the at least two, in particular slot-shaped, openings cover a larger part of the imaginary helix or spiral (35) than the webs (26), - the slot-shaped openings extend along the helix or spiral (35), and / or - the imaginary helix or spiral (35) winds upwards in the opposite direction to the rotational flow (29) of the gas-water mixture flowing into the vortex chamber (16). [9] Mobile fuel cell system (1) according to any one of the preceding claims 1 to 4, wherein the immersion tube (18) has a slot-shaped opening in its area enclosed by the immersion tube bell (19) which extends along an imaginary circle (27) arranged on the surface of the immersion tube (18) and is bounded by a web (26), and optionally the slot-shaped opening covers a larger part of the imaginary circle (27) than the web (26). [10] Mobile fuel cell system (1) according to any one of the preceding claims 1 to 4, wherein - the immersion tube (18) has a slot-shaped opening in its area enclosed by the immersion tube bell (19), which extends along an imaginary helix or spiral (35) enclosing the immersion tube, and in particular - the slot-shaped opening covers an angular range of more than 90°, in particular more than 180°, and / or - the imaginary helix or spiral (35) winds upwards in the opposite direction to the rotational flow (29) of the gas-water mixture flowing into the vortex chamber (16). [11] Mobile fuel cell system (1) according to one of the preceding claims, wherein the tangential cyclone water separator (10) has a guide plate (20), - which, starting in the area of ​​the mixture inlet (11), extends spirally between the immersion tube bell (19) and the housing (17), partially around the immersion tube bell (19), - such that an inner flow channel (28i) extends between the immersion tube bell (19) and an inner side of the guide plate (20i) and an outer flow channel (28a) extends between an outer side of the guide plate (20a) and the housing (17). [12] Mobile fuel cell system (1) according to any one of the preceding claims, wherein - the immersion tube (18) has an inner edge radius on its inner wall at its end face projecting into the vortex chamber (16) and optionally has an outer edge radius on its outer wall, wherein the inner edge radius is larger than the outer edge radius, and / or the inner edge radius is larger than the greatest wall thickness of the immersion tube (18) in the intake area (23), and / or the immersion tube (18) has a drip edge on its outer wall at its end face projecting into the vortex chamber (16), and / or - the immersion tube bell (19) has an inner edge radius on its inner wall at its end face projecting into the vortex chamber (16) and optionally has an outer edge radius on its outer wall, wherein the inner edge radius is larger than the outer edge radius, and / or the inner edge radius is larger than the greatest wall thickness of the immersion tube bell (19), and / or the immersion tube bell (19) has a drip edge on its outer wall at its end face projecting into the vortex chamber (16), - the guide plate (20) has an inner edge radius on its inner wall at its end face projecting into the vortex chamber (16) and optionally has an outer edge radius on its outer wall, wherein the inner edge radius is larger than the outer edge radius, and / or the inner edge radius is larger than the greatest wall thickness of the guide plate (20). [13] Mobile fuel cell system (1) according to any one of the preceding claims, wherein - the tangential cyclone water separator (10) comprises a partition plate (21) which is arranged in the vortex chamber (16) between the mixture inlet (11) and the water outlet (13) and limits a water collection volume (30) extending between the water outlet (13) and the partition plate (21), - the separating plate (21) is curved towards the intake area (23) of the dip tube (18), and - the partition plate (21) has several partition plate openings (32). [14] Mobile fuel cell system (1) according to claim 13, wherein - the partition openings (32) are arranged at the edge outside a partition central area (31), and - the central area of ​​the partition plate (31) is in position and extent as a projection of the intake area (23) in the direction of the immersion tube axis (22) onto the partition plate (21). [15] Mobile fuel cell system (1) according to any one of the preceding claims, wherein - the minimum internal cross-sectional area of ​​the immersion tube (18a) divided by the minimum internal cross-sectional area of ​​the mixture inlet (11a) yields a value of 0.5 to 2, in particular of 0.75 to 1.5, in particular of 0.9 to 1.1, in particular of 1, and / or - the open end-face outer cross-sectional area of ​​the immersion tube bell (19a) divided by the maximum outer cross-sectional area of ​​the intake area (23a) of the immersion tube (18) yields a value of 1 to 3, in particular of 1 to 2.5, in particular of 1.5 to 2.5.

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