Outlet boss of a pressurized fluid storage tank and tank with such a boss

Abstract

A boss (4) for the outlet of a pressurized fluid storage tank (1) comprising a central axial portion (43) adapted to pass through the shell of said tank (1) and itself traversed by at least one channel (8) communicating via its proximal end (81) with the inner chamber (5) of the storage tank and whose distal end (82) is closed along its axis in the same direction XX' as the boss (4), a radial portion (41) referred to as the internal portion adapted to secure it (4) to the shell of the tank (1), and an axial portion (42) referred to as the external portion comprising at least one radial fluid outlet conduit (9) communicating with the channel (8), which external axial portion (42) being adapted to receive around it a fluid distribution head (6) comprising at least one radial conduit (12) opening, via one of its ends, to the outside (14) and communicating, via its opposite end (121), with the conduit (9) of this external axial part (42).Figure for the abridged version: figure 4.

Description

Title of the invention: OUTLET BOSS OF A PRESSURIZED FLUID STORAGE TANK AND TANK COMPRISING SUCH A BOSS Technical field of the invention

[0001] The present invention relates to an outlet boss for a pressurized fluid storage tank and tanks comprising such a boss.

[0002] 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 bar for NGV (Natural Gas for Vehicles) or at least 350 bar or even 700 bar for hydrogen, the casing of such tanks generally being produced by winding or rolling 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. Technical background

[0003] Different types of tanks equipped with such orifices are known: for example, we can cite the patent application EP1234654 of 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 through this part from one side to the other, 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.

[0004] We can also cite patent application EPI 151224 from Alliant Ammunition Systems published on November 7, 2001, which teaches a pressurized gas tank comprising:

[0005] - a storage chamber provided with an access opening,

[0006] - a polar boss or hub passing through this opening, fixed and secured to it- here, and comprising a threaded channel itself passing through this boss or hub from one side to the other, and opening outside the storage chamber,

[0007] - a plastic lining covering the interior of the envelope which delimits the chamber of storage, 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

[0008] - a base or adjustment body, screwed into both the outer end of the boss and in 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.

[0009] Thus in all these devices above and many others, the pressurized fluid storage tanks always comprise 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 the casing thereof, and the internal diameter of which 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 "base" herein, depending on the patent applications and / or the technical data sheets).

[0010] 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 bar for CNG, and even equal to or more than 700 bar for hydrogen, and which stress the boss, the base and the threading which secures them, are significant, requiring even more thick parts to withstand them and the assembly of which is even more critical.

[0011] Furthermore, in the event of accidental tearing of the tank head screwed onto the base, creating an opening of a fairly large diameter communicating with the storage chamber of the tank, the leakage of the pressurized fluid stored there would be significant and could generate even greater risks.

[0012] 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 bar, and on the other hand to reduce the risks associated with leaks, a tank outlet boss has been developed integrating the base and thus forming a single part with it, as taught on the one hand in the prior patent application for which the present application claims the right of priority for the characteristics which are common thereto and on the other hand in the patent application WO2020 / 225262 filed by the Faurecia exhaust systems company and published on November 12, 2020; these prior patent applications describe a boss comprising:

[0013] - an axial central part capable of passing through the casing of said tank and passing through itself by at least one axial channel capable of communicating by its proximal end with the interior chamber of the fluid storage reservoir and the distal end of which is closed,

[0014] - a so-called internal radial part capable of securing said boss with the envelope of the reservoir and to hold the pressure forces of the fluid on this boss, and

[0015] - an axial part called external comprising at least one radial outlet duct of the fluid communicating with the axial canal towards its distal end,

[0016] 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. Summary of the invention

[0017] 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 for 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 the type of fluid (which can be flammable, harmful, etc.).

[0018] 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.).

[0019] Also 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 tank head on the one hand and of the fluid outlet connection elements connected to it on the other hand.

[0020] Such an objective is achieved with a pressurized fluid storage tank outlet boss on the one hand comprising the same central, radial and axial parts, with the same characteristics, as in the document WO2020 / 225262 cited above and on the other hand integrating the fluid distribution head in its external axial part and forming only one piece therewith, the radial conduits of this axial part external and head being then merged, the axial channel of said boss constituting a simple communication conduit.

[0021] The objective of the invention is further 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.

[0022] 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.

[0023] According to the invention, the radial conduits are each capable of receiving, at their end opening outside the boss, any fluid outlet connection element.

[0024] In a particular embodiment, the axial central part of the boss, passing through the casing of said reservoir, comprises a cylindrical part forming a protrusion inside the reservoir beyond the so-called internal radial part of the boss, making it possible to place there any sensor placed by a second channel passing through the axial central part of the boss.

[0025] This new type of pressure fluid storage tank outlet boss, and these new pressure fluid storage tanks meet the set objective, provide numerous advantages and prove their interest, such as:

[0026] - with respect 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 risks and poor sealing, a single part, ensuring according to the present invention all the functions of base and tank head, eliminates such risks

[0027] - the absence of any other fixing part or sealing intermediate simplifies the manufacturing of tanks,

[0028] - there is no longer any risk of the tank head being torn off,

[0029] - to date if a leak is observed in certain situations, at the level of the connection of the fluid outlet connection 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 done 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 (from the head, or in the present invention from the boss itself) from the arrival of the pressurized fluid and thus make the environment of the bottle safe in the event of such a leak.

[0030] - when the tank casing is made by rotational molding reinforced by winding of 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, all the 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 shock on the external face of the boss: the force due to this shock is thus transmitted all the better by this boss according to the invention to the fibers constituting the envelope. Brief description of the figures

[0031] 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 on the one hand an example of embodiment of a boss and a reservoir head according to the prior art, and on the other hand a boss and a reservoir (or bottle) according to the invention, but other embodiments are possible within the scope of the present invention:

[0032] [Fig-1] - [Fig.l] is an exterior profile view of a storage tank of pressurized fluid according to the invention and equipped with a boss according to the invention as shown in Figures 4 to 6.

[0033] [Fig.2] - [Fig.2] is a partial sectional view of [Fig.3] of a following boss the prior art cited above, as taught on the one hand in the prior patent application for which the present application claims the right of priority for the characteristics which are common thereto and on the other hand in patent application WO2020 / 225262, with a tank head assembled on this boss.

[0034] [Fig.3] - [Fig.3] is a longitudinal sectional view along 111,111' of [Fig.l] of a pressurized fluid storage tank equipped with a boss and a tank head according to [Fig.2].

[0035] [Fig.4] - [Fig.4] is a partial sectional view like that of [Fig.2] but concerning a boss according to the invention integrating the tank head.

[0036] [Fig.5] - [Fig.5] is a partial sectional view like that of [Fig.4] but concerning a particular embodiment of a boss according to the invention integrating the reservoir head with a 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.

[0037] [Fig.6] - [Fig.6] is the same partial sectional view as in [Fig.5] but with the axial channel safety closing system in closed position.

[0038] In the following description, identical, similar or analogous elements will be designated by the same reference numbers. Detailed description of the invention

[0039] According to the representation of figures 2 and 3 and in a known manner as taught on the one hand in the prior patent application for which the present application claims the right of priority for the characteristics which are common thereto and on the other hand in the patent application WO2020 / 225262, said tank 1 comprises an envelope 2 which defines the interior chamber 5 for storing the fluid under high pressure and which is capable of holding this high pressure such as at least 250 bar and even 350 or 700 bar, and at least one boss 4, of generally cylindrical shape, at the outlet of the tank 1 for storing fluid under high pressure, comprising:

[0040] - an axial central part 43> of cylindrical shape with the same axis XX' as that of the reservoir as shown in [Fig.l], central part which can be described as internal and which, capable of passing through the casing 2 of said reservoir 1, is itself crossed by at least one axial channel 8 in the same direction as the axis XX', capable of communicating by its proximal end 8i with the internal chamber 5 of the fluid storage reservoir to allow the fluid to exit, 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,

[0041] - a radial part 4i called internal capable of securing said boss 4 with the casing 2 of the tank 1 and to withstand the forces due to the internal pressure of the tank on this boss 4.

[0042] - an axial part 42 called external comprising at least one radial outlet conduit 9 fluid communicating with the channel 8 towards its distal end 82,

[0043] and said boss 4 thus acting as a base capable of receiving directly, around its external axial part 42, a fluid distribution head 6, without any other intermediate part, comprising at least one radial conduit 12 opening, by one of its ends, to the outside 14 of the head 6 and communicating by its opposite end 12i with the conduit 9 of this external axial part 42.

[0044] 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 8i 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 19 which can even constitute, according to the present invention, a safety system as described below and shown in FIGS. 5 and 6.

[0045] The head 6 of the pressurized fluid storage tank according to the prior art of [Fig. 2] is then able to connect to the outlet boss 4 of the tank as described above and for this purpose comprises an internal bore 11 able to fit in a sealed manner around the external axial part 42 of said boss 4, a means 7 of fixing thereto.

[0046] Following the example of figures 2 and 3, the means 7 for fixing the head 6 on the boss 4 is a nut capable of being screwed onto the threaded distal end of the external axial part 42 of the boss 4 and which presses on the reservoir head 6 to fix it and hold it against a shoulder 13 of the central axial part 42 of said boss, and in other embodiments, this fixing means can be a circlip, a pin, or any other means allowing it to be held in position and blocked, the forces to be countered being minimal.

[0047] According to the example of embodiment of the figures, both of the prior art and of the invention:

[0048] - the axial part 42 called external of the boss 4, because located outside 14 of the casing 2 of the tank 1, comprises at least two conduits 9 arranged radially relative to the axis XX' and distributed, uniformly or not, on the periphery of this external axial part 42,

[0049] - and the head 6 comprises at least two conduits 12 also arranged radially relative to the axis XX' and distributed around the head 6, and each capable of aligning itself in the axis of a conduit 9 of this external axial part 42.

[0050] According to the present invention, the channel 8 of said boss 4 constitutes a simple communication conduit, and said fluid distribution head 6 is integrated into the external axial part 42 of said boss 4 and forms only one piece with it, the radial conduits 9 of this external axial part 42 and of the head 6 then being merged and opening out to the outside 14 of the single piece forming the boss 4 and the head 6.

[0051] According to the present invention and the embodiment of figures 5 and 6, 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 6, 42 called external of the boss 4.

[0052] In [Fig. 5], 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), an O-ring 19 ensuring the sealing of this cap 18 with respect to the boss 4.

[0053] In [Fig.6], the plug 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 has a leak, it is then possible to intervene without waiting for the tank to be empty and a seal 21, shown here against a shoulder located at the end of the plug 18 and crushed by it when this plug is closed, ensures the seal between this plug 18 and the channel 8.

[0054] 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 of the cap 18) or controlled by an automatic system (electric, hydraulic, etc.).

[0055] According to the preferred embodiment of [Fig.4], the axial central part 43, 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.

[0056] This axial central part 43, all the more so if it includes such an outgrowth 44, includes at least one second channel 15 which axially passes through this central part 43 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 out 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: ;

[0057] • 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

[0058] • while the sensor for monitoring the interior of the tank 1 in operation has a different temperature range (such as -60°C / +150°C).

[0059] This cylindrical part 44 forming a protrusion inside the tank 1 then makes it possible to obtain a better measurement of the temperature.

[0060] As shown in [Fig. 4] and already indicated previously with regard to the head 6 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 out at 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 capable of receiving each at their opposite end 12i opening outwards 14, any fluid outlet connection element 10, such as a valve connecting the boss 4, thus also forming a reservoir head, to any pipe or pipe supplying the pressurized fluid, or a component providing a safety function, or even a plug.

[0061] The reservoir 1 for storing fluid under pressure 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.

[0062] 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 FIGS. 2 to 4 between the latter and an internal coating 3, such as a thermoplastic or metallic liner, covering the entire internal part of the casing 2 of the tank 1 and covering this radial part 4b

[0063] 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 can be a part of this internal coating 3 or liner, the boss 4 then being an integral part of this coating.

[0064] It is recalled that the pressurized fluid in the tank 1 can be NGV (Natural Gas for Vehicles) at least 250 bar, as well as hydrogen at least 350 bar, but also at pressures greater than or equal to 700 bar.

Claims

Claims

1. Boss (4) for the outlet of a reservoir (1) for storing fluid under pressure, comprising: - an axial central part (43) along an axis XX' capable of passing through the casing (2) of said reservoir (1) and itself traversed by at least one channel (8) capable of communicating via its proximal end (8i) with the inner chamber (5) of the fluid storage reservoir and the distal end (82) of which is closed along its axis in the same direction XX' as the boss (4), - a radial part (4J called internal capable of securing said boss (4) to the casing of the reservoir (1) and of withstanding the pressure forces of the fluid on this boss (4), and - an axial part (42) called external comprising at least one conduit (9) for the radial outlet of the fluid communicating with the channel (8) towards its distal end (82), characterized in that - said boss (4) forms an integrated dispensing head in one piece, - the end (12J of the at least radial conduit (9) opens,by one of its ends, outside (14) of the boss (4) - 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) - and the channel (8) of said boss (4) constitutes a simple communication conduit,

2. Boss (4) for the outlet of a reservoir (1) for storing fluid under pressure 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 one radial conduit (9).

3. Boss (4) for the outlet of a reservoir (1) for storing fluid under pressure according to either of Claims 1 and 2, characterized in that its axial central part (43), 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 beyond the radial part (4J called the internal part of the boss (4).

4. Boss (4) for the outlet of a reservoir (1) for storing fluid under pressure according to any one of claims 1 to 3, characterized in that the axial central part (43) comprises at least one second channel (15) which axially passes through this central part (43) and which is capable of receiving any measuring sensor.

5. Boss (4) for the outlet of a tank (1) for storing fluid under pressure according to any one of claims 1 to 4, characterized in that the so-called external axial part (42) thereof comprises at least two conduits (9, 12) arranged radially relative to the axis XX' and distributed over the periphery of this external axial part (42).

6. Tank (1) for storing pressurized fluid 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 5

7. 1 a J. Tank (1) for storing pressurized fluid according to claim 6 and comprising an internal metallic coating (3) covering the entire interior part of the casing (2) of the tank (1) characterized in that the internal radial part (4J of the boss (4) is a part of this internal coating (3), the boss (4) being an integral part of this coating.

Images