Outlet boss for a pressurized-fluid storage tank, and tank comprising such a boss

Abstract

The invention relates to an outlet boss (4) for a pressurized-fluid storage tank (1), comprising an axial central part (43) able to pass through the envelope of the tank (1) and itself having passing through it at least one channel (8) communicating by its proximal end (81) with the inner chamber (5) of the storage tank, and the distal end (82) of which is closed along its axis of same direction XX' as the boss (4), a radial internal part (41) able to secure the boss (4) to the envelope of the tank (1), and an axial external part (42) comprising at least one radial outlet duct (9, 12) for the fluid that communicates with the channel (8) and opens, by its other opposite end (121), to the outside (14) of the boss (4) and is able to receive therein any fluid outlet connection element (10), the boss (4) forming in one piece an integrated dispensing head.

Description

[0001] DESCRIPTION

[0002] TITLE: OUTLET BOSS OF A PRESSURE FLUID STORAGE TANK AND TANK COMPRISING SUCH A BOSS

[0003] Technical field of the invention

[0004] The present invention relates to an outlet boss for a pressurized fluid storage tank and tanks comprising such a boss.

[0005] The technical sector of the invention is that of the manufacture of fluid storage tanks, such as composite bottles, under pressure and even high pressure such as at least 250 bars for NGV (Natural Gas for Vehicles) or at least 350 bars or even 700 bars for hydrogen, the casing of such tanks generally being produced by winding or winding composite fibers around a metal or thermoplastic liner, and comprising at least one outlet and / or inlet orifice communicating with the fluid storage chamber delimited by the casing of the tank.

[0006] Technical background

[0007] In fact, different types of tanks equipped with such orifices are known: for example, we can cite the patent application EP1234654 from the company Essef Corporation published on February 28, 2002 and teaching a method for manufacturing reinforced thermoplastic composite hollow articles, such as a pressure container, and comprising an axial opening made by inserting, into the envelope of said hollow articles, the neck of a fixing part comprising a threaded channel and passing right through this part, so that on the one hand a portion of the neck of this part presses against the inner surface of the envelope of the hollow article in question and on the other hand, a threaded core is screwed into the end of the threaded channel opening outside this hollow article, which core is pierced by different conduits allowing communication with the storage chamber delimited by said envelope.

[0008] We can also cite patent application EP1 151224 from Alliant Ammunition Systems published on November 7, 2001, which teaches a pressurized gas tank comprising:

[0009] - a storage room with an access opening,

[0010] - a polar boss or hub passing through this opening, fixed and secured to it, and comprising a threaded channel itself passing through this boss or hub from one side to the other, and opening outside the storage chamber,

[0011] - a plastic lining covering the interior of the casing which delimits the storage chamber, securing the end flange of the boss against the interior of the casing and comprising a sleeve portion extending into a portion of the interior of the boss, and

[0012] - a base or adjustment body, screwed both into the outer end of the boss and into the inner sleeve of the plastic lining until it seals against the end of this sleeve, which base is pierced by a conduit allowing communication with the storage chamber.

[0013] Thus in all these devices above and many others, the pressurized fluid storage tanks always have at least one boss, neck or hub (hereinafter referred to as a "boss") comprising a threaded internal bore, put in place during the manufacture of the tank and secured to its casing, and whose internal diameter must be large enough to allow the axial screwing of a base or core or adjustment body (different vocabularies in fact designate this part, which will be called here "base", depending on the patent applications and / or the technical data sheets).

[0014] A head is generally fixed to this base, allowing valves and fittings to be fixed there, and this base is pierced by one or more conduits for communication with the storage chamber: thus the forces due to the internal pressure in the tank, which can therefore be at least 250 bars for CNG, and even equal to or more than 700 bars for hydrogen, and which stress the boss, the base and the thread which secures them, are significant, requiring even more thick parts to withstand it and the assembly of which is even more critical.

[0015] Furthermore, in the event of accidental tearing of the tank head screwed onto the base, creating a fairly large diameter opening communicating with the tank storage chamber, the leakage of the pressurized fluid stored there would be significant and could generate even greater risks.

[0016] Also to reduce the dimensions of the boss and the base and simplify these parts, thus making it possible to reduce the manufacturing costs of the tanks, especially for those at high pressure such as 700 bars, and on the other hand to reduce the risks associated with leaks, a tank outlet boss was developed integrating the base and thus forming a single part with it, as taught in patent application WO2020 / 225262 filed by the Faurecia Exhaust Systems Company and published on November 12, 2020; and which describes a boss comprising:

[0017] - an axial central part capable of passing through the casing of said reservoir and itself crossed by at least one axial channel capable of communicating via its proximal end with the interior chamber of the fluid storage reservoir and the distal end of which is closed,

[0018] - a so-called internal radial part capable of securing said boss with the casing of the tank and of withstanding the pressure forces of the fluid on this boss, and

[0019] - a so-called external axial part comprising at least one radial fluid outlet conduit communicating with the axial channel towards its distal end, and said boss thus acting as a base is capable of receiving directly, around its external axial part without any other intermediate part, a fluid distribution head comprising at least one radial conduit opening, by one of its ends, outside the head to receive there any fluid outlet connection element and communicating, by its opposite end, with the axial conduit of this external axial part.

[0020] Summary of the invention

[0021] Such a previous arrangement certainly partly addresses the drawbacks cited previously in the previously known devices but presents among other things a safety problem in the system of fixing the tank head on such a boss integrating the base as well as in the connection of fluid outlet connection elements on the head: the use of a tank or bottle of pressurized fluid in fact entails risks due to the pressure itself as well as by the type of fluid (which can be flammable, harmful, etc.).

[0022] The elements mounted on the head must therefore be correctly sized (with safety coefficients, etc.) to withstand the pressure, but the assembly of these different elements can lead to risks of leakage due to assembly (incorrect sealing) or due to use (unscrewing due to vibrations, etc.). Therefore, the objective of the present invention is not only to go even further in simplifying the parts and reducing the manufacturing costs of the tanks, but also to ensure greater safety in the fixing and sealing of the different components, including the fluid outlet connection elements connected to it, while providing possibilities for intervening on these elements in the event of a problem.

[0023] Such an objective is achieved with a pressure fluid storage tank outlet boss comprising central, radial and axial portions, described in the document WO2020 / 225262 cited above,

[0024] - the axial central part being able to pass through the casing of said reservoir and itself crossed by at least one channel able to communicate by its proximal end with the interior chamber of the fluid storage reservoir and the distal end of which is closed along its axis in the same direction as the boss,

[0025] - the so-called internal radial part being capable of securing said boss with the casing of the tank and of withstanding the pressure forces of the fluid on this boss,

[0026] - the so-called external axial part comprising at least one radial outlet conduit for the fluid communicating with the channel which itself communicates with the internal chamber towards its distal end, and according to the invention

[0027] - the boss integrates the fluid distribution head of the prior art in its external axial part and forms only one piece with it,

[0028] - the end of the at least one radial conduit opens, through one of its ends, outside the boss

[0029] - which at least one radial conduit communicates, by its opposite end, with the channel, is capable of receiving, at its end, any fluid outlet connection element - the axial channel of said boss constituting a simple communication conduit. The objective of the invention is furthermore achieved by a safety system operated from the outside, which closes the distal end of the axial channel and which is capable of closing the radial conduits opening outside the boss and communicating, when the safety system is open, with the axial channel, which makes it possible to intervene on the fluid outlet connection elements, connected to the radial conduits, in the event of a problem, such as a sealing defect, because the closing of the safety system isolates these elements which can then be dismantled despite the pressure of the fluid contained in the tank.

[0030] The objective of the present invention is also achieved by a pressurized fluid storage tank comprising at least, from its manufacture, an outlet boss for this fluid such as above, integrating both the base and the fluid distribution head and forming with them a single part without any other connecting, fixing or sealing part.

[0031] In a particular embodiment, the axial central part of the boss, passing through the casing of said tank, comprises a cylindrical part forming a protrusion beyond the so-called internal radial part of the boss, and therefore inside the tank, allowing any sensor placed therein by a second channel passing through the axial central part of the boss.

[0032] This new type of pressure fluid storage tank outlet boss, and these new pressure fluid storage tanks meet the set objective, bring many advantages and prove their interest, such as:

[0033] - compared to boss / base and head assemblies threaded and fixed around its external axial part of the boss / base essentially by a nut screwed onto it and locking the head against a shoulder, and which then present safety and poor sealing risks, a single part, ensuring according to the present invention all the functions of base and tank head, eliminates such risks

[0034] - the absence of any other fixing part or sealing intermediate simplifies the manufacture of the tanks,

[0035] - there is no longer any risk of the tank head being torn off,

[0036] - to date, if a leak is found in certain situations, at the level of the connection of the fluid outlet connector elements on the tank head (in the present invention on the boss itself therefore), as it is not possible to intervene on this bottle head, because of the danger that can be caused by this leak, the repair can only be carried out when the bottle or the tank is completely emptied: according to the present invention, the closure system, called safety, makes it possible to isolate all the outlets of the boss from the arrival of the pressurized fluid and thus make the environment of the bottle safe in the event of such a leak.

[0037] - when the shell of the tank is made by rotational molding reinforced by winding composite carbon fibers, these fibers are wound and supported around the so-called internal radial part, forming a groove between the internal radial and external axial parts, and this makes it possible, even more so when the boss integrates and forms a single part with the head, to absorb and transmit the energy of the boss to the composite fibers when the tank is subjected to an axial impact on the external face of the boss: the force due to this impact is thus transmitted even better by this boss according to the invention to the fibers constituting the shell.

[0038] Brief description of the figures

[0039] Other characteristics and advantages of the invention will appear during the reading of the detailed description which follows for the understanding of which reference will be made to the attached figures which show various examples of embodiment of a boss and a reservoir (or bottle) according to the invention, but other embodiments are possible within the scope of the present invention:

[0040] [Fig.1 ] - Figure 1 is an external profile view of a pressurized fluid storage tank according to the invention and equipped with a boss according to the invention as shown in Figures 2 to 9 . [Fig.2 ] - Figure 2 is a partial longitudinal sectional view, along I II, II I' of Figure 1 , of the upper part of the tank equipped with a boss according to the invention.

[0041] [Fig.3] - Figure 3 is a partial sectional view like that of Figure 2 but concerning a particular embodiment of a boss according to the invention, therefore integrating the reservoir head of the prior art, with a first type of safety closing system, in the open position, of the axial channel capable of communicating by its proximal end with the interior chamber of the fluid storage reservoir.

[0042] [Fig. 4] - Figure 4 is the same partial sectional view as in Figure 3 but with the axial channel safety closure system in the closed position.

[0043] [Fig.5] - Figure 5 is a partial sectional view, like that of Figure 3, and concerning another particular embodiment of a boss according to the invention with a second type of safety closing system, in the closed position, of the axial channel, and combined with an axial outlet or inlet equipped with a so-called self-sealing system, also in the closed position.

[0044] [Fig.6] - Figure 6 is the same partial sectional view as in Figure 5, with the second type of axial channel safety closure system in the open position, and the so-called self-sealing system still in the closed position. [Fig.7] - Figure 7 is the same partial sectional view as in Figures 5 and 6, with the second type of axial channel safety closure system in the open position, and the so-called self-sealing system also in the open position.

[0045] [Fig.8] - Figure 8 is a partial sectional view, like that of Figure 3, and concerning another particular embodiment of a boss according to the invention without a safety closing system for the axial channel, but with an axial outlet or inlet equipped with a so-called self-sealing system, in the closed position.

[0046] [Fig.9] - Figure 9 is the same partial sectional view as in Figure 8 but with the so-called self-sealing system in the open position.

[0047] In the following description, identical, similar or analogous elements will be designated by the same reference numbers.

[0048] Detailed description of the invention

[0049] In a known manner as taught in the patent application WO2020 / 225262 cited above, said reservoir 1 comprises an envelope 2 which defines the interior chamber 5 for storing the fluid under high pressure and which is capable of withstanding this high pressure such as at least 250 bars and even 350 or 700 bars, and at least one boss 4, of generally cylindrical shape, for the outlet of the reservoir 1 for storing fluid under high pressure, comprising: an axial central part 4s, of cylindrical shape with the same axis XX' as that of the reservoir as shown in FIG. 1, a central part which can be described as internal and which, passing through the envelope 2 of said reservoir 1, is itself passed through by at least one axial channel 8 in the same direction as the axis XX', communicating by its proximal end 81 with the interior chamber 5 of the reservoir for storing the fluid to allow the outlet thereof,and the distal end 82 of the channel 8 of which is closed along its axis in the same direction XX' as the boss 4, a radial part 4i called internal securing said boss 4 with the casing 2 of the reservoir 1 and capable of withstanding the forces due to the internal pressure of the reservoir on this boss 4. an axial part 42 called external comprising at least one conduit 9 for radial outlet of the fluid communicating with the channel 8 towards its distal end 82.,

[0050] And according to the invention, said boss 4 thus not only acts as a base but also forms in a single piece an integrated fluid distribution head, without any other intermediate part and

[0051] - the end 12i of the at least one radial conduit 9 opens, by one of its ends, to the outside 14 of the boss 4

[0052] - which at least radial conduit 9 communicating, by its opposite end, with the channel 8, is capable of receiving, at its end 12i any fluid outlet connection element 10

[0053] - and channel 8 of said boss 4 constitutes a simple communication conduit,

[0054] The closing of the distal end 82 of the channel 8 can be carried out during the machining of the boss 4 either by not drilling the channel 8 all the way from its proximal end 81 or by drilling until it opens out outside the boss 4 and then closing this drilling in a sealed manner such that, after producing a thread and other possible and / or necessary machining operations, by then screwing in a sealing plug 18 which can even constitute, according to the present invention, a safety system as described below and shown in FIGS. 3 to 7.

[0055] According to the embodiments of the figures, the axial part 42 called external of the boss 4, because located outside 14 of the casing 2 of the reservoir 1, comprises at least two conduits 9 arranged radially with respect to the axis XX' and distributed, uniformly or not, on the periphery of this external axial part 42. According to the present invention and the embodiments of figures 3 to 9, the distal end 82 is closed by a safety system 18 operated from the outside 14 and which is capable of closing the radial conduits 9, 12: this can thus be, as shown, a plug 18 which is screwed 20 into the axis of the channel 8 by the upper face of the axial part 42 called external of the boss 4.

[0056] In Figure 3, the cap 18 is shown unscrewed in the open position and thus releases the distal end 82 of the channel 8 which thus communicates with the radial channels 9, 12 and allows the fluid stored in the chamber 5 of the storage tank to pass freely towards the outside 14, and therefore towards all fluid outlet connection elements 10 which would be connected to these radial channels 9, 12 (see below), a seal 19, which may be toric or of another shape, ensuring the sealing of this cap 18 with respect to the boss 4.

[0057] In Figure 4, the cap 18 is shown screwed (operation which can be done from the outside 14) in the closed position and then closing the distal end 82 of the channel 8, it closes the latter and no longer allows the passage of fluid towards the radial channels 9, 12 and therefore towards any fluid outlet connection element 10 which would be connected thereto: if one of these elements 10 thus presents a failure, such as a leak or other, it is then possible to intervene without waiting for the reservoir to be empty and a seal 21, shown here against a shoulder located at the end of the cap 18 and crushed by it when closing this cap, ensures the seal between this cap 18 and the channel 8.

[0058] The operation of this safety system 18 can be carried out mechanically (by manual closing as shown in the figures by turning, with a key for example, the head 183 of the stopper 18 forming its proximal end) or controlled by an automatic system (electric, hydraulic, etc.).In Figures 5 to 7, the plug 18 comprises a fluid outlet or inlet 7, which may be axial, and which makes it possible, for example, to connect the reservoir 1 to other fluid storage sources and in particular to fill or empty it: for this purpose, the distal end 82 of the channel 8 of the boss 4 can be closed by the plug 18, operated from the outside 14 (as in the other embodiment of Figure 4), the latter comprises a channel 22 opening by its distal end 22i into the outlet / inlet 7 and by its other opposite proximal end into a conduit 23 (which may be a bore surrounding the stem 1 81 of the plug 18) communicating with the distal end 182 of the plug.

[0059] This distal end 82 of the plug is inserted into a bore of a sealing valve 6 which comprises a sealing ball 11 held closed, against the opening of the conduit 23, by a spring 13 and which can be opened by the operation of the head 183 of the plug 18, the distal end 182 of the latter then pushing the ball 11 which thus compresses the spring 13 and opens the passage allowing the fluid either to escape or to enter the reservoir 1 via the channel 8: such a system is said to be self-sealing capable of opening the communication between the channel 8 and the channel 22, and therefore towards the exterior 14, by displacement of the plug 18 which here acts as a connector activating the valve 6 which ensures the manual safety closing function.

[0060] According to figures 5 to 7 the sealing valve 6 is intermediate between the plug 18, which is then screwed 24 into this valve 6, and the axial part 42 called external of the boss 4 into which the valve 6 is screwed: the latter, when it is completely closed, as in figure 5, by its screwing 20 into the axial part 42, crushes the seal 21 and, as for the other embodiment of figure 4, ensures the seal between the plug 18 and the channel 8; no passage of fluid is then possible towards the radial channels 9, 12 and therefore towards any fluid outlet connection element 10 which would be connected thereto. On the other hand, according to figures 8 and 9, the sealing valve 6 is certainly also screwed into the axial part 42 of the boss 4 but in a fixed manner and which may be in the same thread 20 as that of the plug 18: in this embodiment, the latter comprises a fluid outlet or inlet 7 but no safety system capable of closing the at least one radial conduit 9.

[0061] Thus, either the boss 4 comprises only a safety system 18 capable of closing the channel 8 and of blocking the radial conduits 9, 12, or a self-sealing system capable of opening / closing the communication between the channel 8 and a fluid outlet / inlet channel 22, or a combination of the safety system 18 comprising a self-sealing system.

[0062] According to the preferred embodiment of Figure 2, the axial central part 4s, passing through the casing 2 of said reservoir 1 and itself passed through by at least one channel 8, comprises a cylindrical part 44 forming a protrusion inside the reservoir 1 beyond the so-called internal radial part 4i.

[0063] This axial central part 4s, all the more so if it comprises such an outgrowth 44, comprises at least one second channel 15 which axially passes through this central part 4s and which is capable of receiving any measuring sensor such as temperature, which is very useful for monitoring the operation of the tank 1 in operation and is even necessary during the manufacture of the latter when it is produced by rotational molding such as by winding composite carbon fibers;and as in these two uses, it is not the same, it is necessary to be able to remove it and replace it by sliding it into this second channel 15 from the outside 14, knowing that the end of this second channel thus opening to the outside is closed by a stuffing box or plug 16 to maintain the internal pressure of the tank 1 and its other end opening into the tank 1 can itself be protected from the fluid inside the tank 1 by a device of the glove finger type 17: the sensor for controlling the temperature during the manufacture of the tank 1 by rotational molding has a temperature range of 20 to 260°C while the sensor for controlling the interior of the tank 1 in operation has a different temperature range (such as -60°C / + 150°C).;

[0064] This cylindrical part 44 forming a protrusion inside the tank 1 then makes it possible to obtain a better measurement of the temperature.

[0065] As shown in Figure 2 and already indicated previously with regard to the tank head of the prior art, the axial part 42 called external of the boss 4, comprises at least two conduits 9, 12 arranged radially with respect to the axis XX' and distributed on the periphery of this external axial part 42 of the boss: these radial conduits 9, 12, opening to the outside 14 of the boss 4 and communicating by their internal end to the boss 4 with the channel 8 closed at its distal end 82, are each able to receive at their opposite end 12i opening towards the outside 14, any fluid outlet connection element 10, such as a valve connecting the boss 4, thus also forming the tank head, to any pipe or pipe supplying the pressurized fluid, or a component ensuring a safety function, or even a cap.

[0066] The reservoir 1 for storing pressurized fluid according to the invention, as shown in the attached figures, comprises at least one boss 4 for the outlet of this fluid in accordance with the description above, integrating both the functions of base and head of the reservoir in a single piece according to the characteristics explained previously: such a boss 4 also allows, in addition to the advantages already indicated previously, such as very good resistance to mechanical stresses, axial resistance along XX' of the casing during manufacture with good axial positioning.The securing of the radial part 4i with the casing 2 of the tank 1, in order to withstand the forces due to the internal pressure of the tank on the boss 4, can be achieved by gluing or molding against this casing 2 or, as shown in figures 2 to 4 between the latter and an internal coating 3, such as a thermoplastic or metallic liner, covering the entire interior part of the casing 2 of the tank 1 and covering this radial part 4i.

[0067] In a particular embodiment, when the tank 1 comprises an internal metallic coating 3 covering the entire interior part of the casing 2 of the tank 1, the internal radial part 4i of the boss 4 may be a part of this internal coating 3 or liner, the boss 4 then being an integral part of this coating. It is recalled that the pressurized fluid in the tank 1 may be NGV (Natural Gas for Vehicles) at at least 250 bars, as well as hydrogen at at least 350 bars, but also at pressures greater than or equal to 700 bars.

Claims

DEMANDS 1. Boss (4) for the outlet of a pressurized fluid storage tank (1) comprising: - a central axial part (4s) along an axis XX' passing through the envelope (2) of said reservoir (1) and itself traversed by at least one channel (8) communicating by its proximal end (81) with the inner chamber (5) of the fluid storage reservoir and whose distal end (82) is closed along its axis of the same direction XX' as the boss (4), - a radial part (4i), called the internal part, securing said boss (4) to the tank casing (1) and capable of withstanding the fluid pressure forces on this boss (4), and - an axial portion (42), referred to as the external portion, comprising at least one radial outlet conduit (9) for the fluid communicating with the channel (8) at its distal end (82), characterized in that - said boss (4) forms in one piece an integrated distribution head, - the end (12i) of the at least radial conduit (9) opens, at one of its ends, to the outside (14) of the boss (4) - which at least radial conduit (9) communicating, at its opposite end, with the channel (8), is suitable for receiving, at its end (12i) any fluid outlet connection element (10) - and the channel (8) of the said boss (4) constitutes a simple communication conduit, 2. Boss (4) outlet of pressurized fluid storage tank (1) according to claim 1 characterized in that the distal end (82) of the channel (8) of said boss (4) is closed by a safety system (18) operated from the outside (14) and which is capable of closing the at least radial conduit (9).

3. Boss (4) outlet of pressurized fluid storage tank (1) according to claim 1 characterized in that the distal end (82) of the channel (8) of said boss (4) is closed by a plug (18) operated from the outside (14) and which comprises a channel (22) opening by its distal end (22i) into an axial outlet / inlet (7) of fluid and by its other opposite proximal end into a conduit (23) communicating with the distal end (I 82) of the plug (18) which is inserted into a self-sealing system capable of opening the communication between the channel (8) and the channel (22) by displacement of the plug (18).

4. Boss (4) outlet of pressurized fluid storage tank (1) according to claim 2 characterized in that the safety system (18) comprises a self-sealing system according to claim 3.

5. Boss (4) outlet of pressurized fluid storage tank (1) according to any one of claims 1 to 4 characterized in that its axial central part (4s), passing through the shell (2) of said tank (1) and itself traversed by at least one channel (8), comprises a cylindrical part (44) forming an outgrowth beyond the radial part (4i) called internal of the boss (4).

6. Boss (4) outlet of pressurized fluid storage tank (1) according to any one of claims 1 to 5 characterized in that the axial central part (4s) comprises at least one second channel (15) which axially passes through this central part (4s) and which is suitable for receiving any measuring sensor.

7. Boss (4) for the outlet of a pressurized fluid storage tank (1) according to any one of claims 1 to 6, characterized in that the axial portion (42), referred to as the external portion, comprises at least two conduits (9, 12) arranged radially by in relation to the XX' axis and distributed over the periphery of this external axial part (42).

8. A pressurized fluid storage tank (1) comprising at least one outlet boss (4) for this fluid, characterized in that this outlet boss (4) is according to any one of claims 1 to 7.

9. A pressurized fluid storage tank (1) according to claim 8 and comprising an internal metallic lining (3) covering the entire inner part of the shell (2) of the tank (1) characterized in that the internal radial part (4i) of the boss (4) is a part of this internal lining (3), the boss (4) being an integral part of this lining.

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