Outlet boss for pressurized fluid storage tank and tank comprising such boss

Abstract

The invention relates to an outlet boss (4) for a pressurized fluid tank (1), comprising: an axial central part (43) passing through the housing of the tank (1) and itself having at least one passage (8) therethrough communicating with an internal chamber (5) of the tank through a proximal end (81) thereof, and the distal end (82) of the at least one channel is closed along its axis XX'in the same direction as the boss (4); a radially inner part (41) capable of fixing the boss (4) to the housing of the tank (1); and an axially outer part (42) comprising at least one radial outlet duct (9, 12) for the fluid communicating with the channel (8) and opening through the other opposite end (121) thereof to the exterior (14) of the boss (4) and capable of receiving therein any fluid outlet connection element (10), the boss (4) integrally forming a one-piece dispensing head.

Description

Technical Field

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

[0002] The technical field of the present invention is the manufacture of fluid storage tanks under pressure or 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, such as bottles made of composite materials, the outer shell of such tanks being generally made by winding or coiling composite fibers around a metal or thermoplastic lining and comprising at least one outlet and / or inlet opening connected to a fluid storage chamber defined by the tank shell. Background Art

[0003] Various types of tanks equipped with such orifices are known: for example, patent application EP1234654, published by Essef Corporation on February 28, 2002, teaches a method for manufacturing a reinforced thermoplastic composite hollow object (such as a pressurized container), which reinforced thermoplastic composite hollow object includes an axial opening, which is produced by inserting the neck of a fastening component in the shell of the hollow object, the neck of the fastening component including a threaded channel and passing through the component so that, on the one hand, the collar portion of the component is pressed against the inner surface of the shell of the hollow object, and on the other hand, a threaded core is screwed into the end of the threaded channel leading to the outside of the hollow object, the core being penetrated by various ducts allowing communication with a storage chamber defined by the shell.

[0004] Another example is patent application EP1151224 published by Alliant Ammunition Systems on November 7, 2001, which teaches a pressurized gas cylinder comprising:

[0005] - a storage chamber having an access opening,

[0006] a polar boss or hub which passes through the opening, is fixed and integral therewith and comprises a threaded passage which passes right through the boss or hub and opens to the exterior of the storage chamber,

[0007] a plastic liner lining the interior of the housing defining the storage chamber, the plastic liner securing the end flange of the boss to the interior of the housing and comprising a sleeve portion extending into a portion of the interior of the boss, and

[0008] - A base or fitting body which is screwed into the outer end of the boss and into the internal sleeve of the plastic liner until it seals against the end of the sleeve, the base being pierced by a duct capable of communicating with the storage chamber.

[0009] Thus, in all of the above-described arrangements and many others, the pressurized fluid storage tank is always characterized by at least one boss, neck or hub (hereinafter referred to as a "boss") having a threaded inner hole, which is assembled during tank manufacture and is integral with the tank housing; the inner diameter of this hole must be large enough to allow a base, core or assembly body to be axially screwed therein (different terms may be used in patent applications and / or technical data sheets to refer to this component, which will be referred to herein as the "base").

[0010] The base is typically fitted with a head to which valves and fittings can be attached, and is pierced by one or more pipes communicating with the storage chamber: this means that the internal pressure of the tank (which can be at least 250 bar for NGV and even 700 bar or more for hydrogen) exerts considerable stress on the boss, the base and the external threads connecting them, making it more necessary to use thicker parts to withstand the stress and making assembly more critical.

[0011] Furthermore, in the event that the can head screwed into the base were to accidentally become dislodged, thereby creating an opening of considerable diameter communicating with the storage chamber of the can, leakage of the pressurized fluid stored therein would be significant and could create an even greater risk.

[0012] In order to reduce the size of the boss and the base and to simplify these parts, thereby reducing the tank manufacturing costs (especially for high-pressure tanks such as 700 bar), and also reducing the risks associated with leakage, a tank outlet boss has been developed, which integrates the base and thus forms a single part with it, as described in patent application WO2020 / 225262 filed by Faurecia Exhaust Systems and published on November 12, 2020; and this patent application describes a boss comprising:

[0013] - an axial central part capable of passing through the outer shell of the tank and itself traversed by at least one axial channel capable of communicating with the internal chamber of the fluid storage tank through its proximal end and whose distal end is closed,

[0014] a radial part (called radial inner part) capable of fixing said boss to the outer shell of the tank and capable of maintaining the fluid pressure on said boss, and

[0015] an axial part (referred to as axial outer part) comprising at least one radial fluid outlet duct communicating with the axial channel towards the distal end of the axial channel,

[0016] And thus, said boss acting as a base is able to receive directly around its axially external part a fluid dispensing head without any other intermediate part, the fluid dispensing head comprising at least one radial duct opening outside the head through one of its ends to receive any fluid outlet connection element and communicating through its opposite end with the axial duct of the axially external part. Summary of the invention

[0017] Of course, this arrangement does partially overcome the above-mentioned shortcomings of previously known devices, but in a system for attaching a can head to such a boss with an integrated base and at the connection of the fluid outlet connecting element to the head, this arrangement also presents safety issues: using pressurized fluid cans or bottles will bring risks due to the pressure itself and the type of fluid (which may be flammable, hazardous, etc.).

[0018] Therefore, the head-mounted components must be correctly sized (with safety factors, etc.) to withstand the pressure, but the assembly of these various components may lead to the risk of leakage due to assembly (incorrect sealing) or use (loosening due to vibration, etc.).

[0019] Therefore, the purpose of the present invention is not only to further simplify the components and reduce the manufacturing costs of the tank, but also to ensure that the various components (including the fluid outlet connection elements connected thereto) have higher safety when attached and sealed, while enabling these elements to be operated in the event of problems.

[0020] As described in the above-mentioned document WO 2020 / 225262, such objects are achieved by an outlet boss for a pressurized fluid storage tank, the outlet boss having a central part, a radial part and an axial part,

[0021] - the axial central part is able to pass through the housing of the tank and has at least one passage passing through it, the at least one passage communicating with the internal chamber of the fluid storage tank through its proximal end and the distal end of the at least one passage being closed along its axis in the same direction as the boss,

[0022] the radially inner part is capable of fixing said boss to the outer shell of the tank and maintaining the pressure of the fluid on the boss,

[0023] the axially outer part comprises at least one radial outlet duct for the fluid, which at least one radial outlet duct communicates with the channel, which channel itself communicates with the internal chamber towards its distal end,

[0024] And according to the present invention,

[0025] - the boss integrates the fluid dispensing head of the prior art in its axially outer part and forms a single part therewith,

[0026] - the end of at least one radial duct opens outwardly on the boss through one of its ends,

[0027] - the at least one radial duct communicating with the channel through its opposite ends is capable of receiving at its ends any fluid outlet connection element,

[0028] - This axial channel of the boss constitutes a simple communicating duct. The object of the invention is also achieved by an externally operated safety system which closes the distal end of the axial channel and is able to close the radial duct which opens outside the boss and which communicates with the axial channel when the safety system is open; this makes it possible to operate the fluid outlet connection elements connected to the radial ducts in the event of a problem (such as a leak), since closing the safety system isolates these elements, which can then be removed regardless of the pressure of the fluid contained in the tank.

[0029] The objects of the present invention are also achieved by a pressurized fluid storage tank which, at least from the beginning of its manufacture, comprises an outlet boss for the fluid as described above, which integrates both the base and the fluid dispensing head and forms a single component with them without any other connection, attachment or sealing parts.

[0030] In a specific embodiment, the axial center part of the boss that passes through the shell of the tank includes a cylindrical part that forms a protrusion that extends beyond the radial inner part of the boss and thus enables any sensor placed there to be assembled inside the tank through a second channel that passes through the axial center part of the boss.

[0031] This new pressurized fluid tank outlet boss and these new pressurized fluid tanks meet the set purpose, provide many advantages and prove their worth, such as:

[0032] - Compared to boss / base and head assemblies, which are basically threaded and attached around the axially outer part of the boss / base by a nut that is screwed into the axially outer part of the boss / base and locks the head on a shoulder, and which then create safety and sealing risks, the single component according to the present invention performs all the functions of the base and the can head, eliminating such risks.

[0033] - The absence of additional attachments or sealing components simplifies tank manufacturing,

[0034] - No more risk of the can head falling off,

[0035] - Until now, if, in certain cases, a leak was detected at the connection of the fluid outlet connection element on the can head (in the present invention, on the boss itself), it was not possible to carry out work on this bottle head due to the danger that could be caused by this leak, and repairs could only be carried out when the bottle or can was completely emptied: according to the present invention, a so-called safety closure system makes it possible to isolate all boss outlets from the inflow of pressurized fluid, thus ensuring the safety of the bottle environment in the event of such a leak.

[0036] - When the outer shell of the tank is produced by rotational molding reinforced by winding composite carbon fibers, these fibers are wound and supported around the radial inner part, thereby forming a groove between the radial inner part and the axial outer part, and this makes it possible to achieve the following (especially when the boss integrates the head and forms a single part with the head): when the tank is subjected to an axial impact on the outer surface of the boss, energy is absorbed from the boss and transferred to the composite fibers: therefore, the force generated by the impact is more effectively transferred by the boss according to the present invention to the fibers constituting the outer shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Further features and advantages of the invention will become apparent during the course of the following detailed description, for which reference is made to the accompanying drawings which show various examples of embodiments of bosses and cans (or bottles) according to the invention, although other embodiments are possible within the scope of the invention:

[0038] Figure 1 Is equipped with Figures 2 to 9 An external outline view of a pressurized fluid storage tank of the present invention is shown with a boss according to the present invention.

[0039] Figure 2 It is along Figure 1 Partial longitudinal sectional views of the upper part of a tank equipped with a boss according to the present invention as shown in III, III'.

[0040] Figure 3 is similar to Figure 2A partial cross-sectional view of the present invention, but relating to a specific embodiment of a boss according to the present invention, thus combining a can head of the prior art, the boss having a first type of safety closure system in an open position with an axial channel capable of communicating with the internal chamber of a fluid storage tank via its proximal end.

[0041] Figure 4 is with Figure 3 Same partial cutaway view, but with the axial channel safety closure system in the closed position.

[0042] Figure 5 is similar to Figure 3 A partial sectional view of a boss according to the invention, which relates to another specific embodiment of the boss, which has a second type of safety closure system of the axial channel in the closed position and is combined with an axial outlet or inlet, which is equipped with a so-called self-closing system also in the closed position.

[0043] Figure 6 is with Figure 5 The same partial cross-sectional view with the second type of axial channel safety closing system in the open position and the so-called self-closing system still in the closed position.

[0044] Figure 7 is with Figure 5 and Figure 6 The same partial cross-sectional view with an axial channel safety closing system of the second type in the open position and a so-called self-closing system also in the open position.

[0045] Figure 8 is similar to Figure 3 A partial sectional view of another specific embodiment of a boss according to the invention, which boss does not have a safety closure system for the axial channel, but has an axial outlet or inlet, which is equipped with a so-called self-closing system in the closed position.

[0046] Fig. 9 is with Figure 8 Same partial cutaway view, but with the self-closing system in the open position.

[0047] In the following description, the same, similar or like elements will be referred to by the same reference numerals. DETAILED DESCRIPTION

[0048] In a known manner as taught in the aforementioned patent application WO2020 / 225262, the tank 1 comprises: a housing 2 defining an internal chamber 5 for storing a fluid under high pressure and capable of withstanding such high pressure, such as at least 250 bar or even 350 bar or 700 bar; and at least one boss 4 having a substantially cylindrical shape, at the outlet of the tank 1, for storing a fluid under high pressure, the at least one boss comprising:

[0049] - an axial central part 43, which is cylindrical and has the same Figure 1 the same axis XX' as the axis of the tank shown, the central part can be described as internal and passes through the shell 2 of the tank 1, the central part itself being traversed by at least one axial channel 8 having the same direction as the axis XX', the at least one axial channel communicating with the internal chamber 5 of the fluid storage tank through its proximal end 81 so as to enable the internal chamber of the fluid storage tank to leave, and the distal end 82 of the channel 8 being closed along its axis XX' in the same direction as the boss 4,

[0050] A radially internal part 41 which fixes said boss 4 to the outer shell 2 of the tank 1 and is able to sustain the forces generated on this boss 4 due to the internal pressure of the tank.

[0051] An axially outer part 42 comprising at least one radial fluid outlet duct 9 communicating with the channel 8 towards its distal end 82 .

[0052] And according to the present invention, the boss 4 not only acts as a base, but also integrally forms a one-piece fluid dispensing head without any other intermediate parts, and

[0053] - the end 121 of at least one radial duct 9 opens out on the exterior 14 of the boss 4 via one of its ends,

[0054] the at least one radial duct 9 communicating with the channel 8 through its opposite end is capable of receiving at its end 121 any fluid outlet connection element 10,

[0055] - And the channel 8 of the boss 4 constitutes a simple connecting pipe.

[0056] The distal end 82 of the channel 8 can be closed during the machining of the boss 4 by not drilling the channel 8 all the way through from the proximal end 81 thereof, or drilling until it emerges outside the boss 4, and then closing the hole in a sealed manner, such as, after threading and other possible and / or necessary machining, by screwing in a sealing plug 18, which may even constitute the following and Figures 3 to 7Security system shown.

[0057] According to the exemplary embodiment shown in the figure, the axially outer part 42 of the boss 4 located on the outside 14 of the shell 2 of the tank 1 has at least two pipes 9, which are radially arranged relative to the axis XX' and are evenly or unevenly distributed on the periphery of the axially outer part 42.

[0058] According to the present invention and Figures 3 to 9 In the exemplary embodiment shown in , the distal end 82 is closed by a safety system 18, which is operated from the outside 14 and is able to close the radial ducts 9, 12: as shown in the figure, this can be a plug 18, which is screwed into the axis of the channel 8 20 through the upper surface of the axially external part 42 of the boss 4.

[0059] exist Figure 3 In the figure, the plug 18 is shown as being unscrewed in the open position, thereby releasing the distal end 82 of the channel 8, which channel is thus connected to the radial channels 9, 12 and allows the fluid stored in the chamber 5 of the tank to pass freely to the outside 14, and therefore to any fluid outlet connection element 10 connected to these radial channels 9, 12 (see below), and the seal 19 can be annular or have another shape to ensure that the plug 18 is sealed relative to the boss 4.

[0060] exist Figure 4 In the figure, the plug 18 is shown as being screwed in the closed position (operation can be performed from the outside 14), thereby closing the distal end 82 of the channel 8 and preventing the fluid from passing to the radial channels 9, 12 and therefore to any fluid outlet connection element 10 connected thereto: if one of these elements 10 fails (such as a leak, etc.), intervention can be carried out without waiting for the tank to be emptied, and the gasket 21 ensures that there is a seal between the plug 18 and the channel 8, which gasket is shown here as abutting against a shoulder located at the end of the plug 18 and being squeezed by this shoulder when the plug is closed.

[0061] The safety system 18 may be mechanically operated (by manual closure as shown in the figures, for example, by turning the head 183 of the plug forming the proximal end of the plug 18 using a key) or controlled by an automatic (electrical, hydraulic, etc.) system.

[0062] exist Figures 5 to 7 In the embodiment, the plug 18 has a fluid outlet or inlet 7 which may be axial and which enables, for example, the tank 1 to be connected to another fluid storage source and in particular to be filled or emptied: 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 Figure 4In another exemplary embodiment shown in ), the plug includes a channel 22 which opens to the outlet / inlet 7 at its distal end 221 and opens to a conduit 23 (which can be a hole surrounding the rod 181 of the plug 18) at its other opposite proximal end that is connected to the distal end 182 of the plug.

[0063] This distal end 182 of the plug is inserted into the hole of the sealing valve 6, which includes a sealing ball 11, which is kept closed against the opening of the pipe 23 by a spring 13 and can be opened by manipulating the head 183 of the plug 18, the distal end 182 of the plug then pushing the ball 11, which thereby compresses the spring 13 and opens the channel, allowing the fluid to escape or re-enter the tank 1 via the channel 8: such a system is considered to be self-closing, being able to open the communication between the channel 8 and the channel 22, and therefore to the outside 14, by the displacement of the plug 18, the plug acting herein as a connection to activate the valve 6, which provides a manual safety closure function.

[0064] according to Figures 5 to 7 , the sealing valve 6 is located between the plug 18 and the axially outer part 42 of the boss 4, the plug is then screwed 24 into the valve 6, and the valve 6 is screwed into the axially outer part: when Figure 5 When fully closed, the valve is pressed against the gasket 21 by screwing into the axial part 42 20 and Figure 4 As in the other embodiment of the present invention, it is ensured that there is a seal between the plug 18 and the channel 8; no fluid can then pass through the radial channels 9, 12 and thus through any fluid outlet connection element 10 connected to them.

[0065] On the contrary, according to Figure 8 and Fig. 9 , the sealing valve 6 is also screwed into the axial part 42 of the boss 4, but in a fixed manner and possibly in the same thread 20 as the plug 18: in this embodiment, there is a fluid outlet or inlet 7, but there is no safety system capable of closing at least one radial duct 9.

[0066] Therefore, the boss 4 comprises only a safety system 18 capable of closing the channel 8 and sealing the radial ducts 9 , 12 , or a self-sealing system capable of opening / closing the communication between the channel 8 and the fluid outlet / inlet channels 22 , or a combination of safety systems 18 including a self-sealing system.

[0067] exist Figure 2 In the preferred exemplary embodiment shown, the axial central part 43 comprises a cylindrical part 44 which passes through the outer shell 2 of the tank 1 and is itself traversed by at least one passage 8 and which forms a projection inside the tank 1 beyond the radially inner part 41 .

[0068] This axial central part 43 (especially if it comprises such a projection 44) comprises at least one second channel 15 which passes axially through this central part 43 and is suitable for receiving any measuring sensor (such as a temperature sensor) which is very useful for monitoring the working of the tank 1 in operation and is even necessary during its manufacture when the tank is made by rotational molding (such as by winding composite carbon fibers); and since this measuring sensor is different in these two applications, it must be possible to remove and replace it by sliding it from the outside 14 into this second channel 15, noting that the end of this second channel leading to the outside is sealed by a gland or plug 16 to maintain the pressure inside the tank 1, and its other end leading into the tank 1 can itself be protected from the fluid inside the tank 1 by means of an immersion sleeve type 17:

[0069] the sensor for monitoring the temperature during the manufacture of the can 1 by rotational moulding has a temperature range of 20°C to 260°C,

[0070] • Whereas the sensor used to monitor the interior of the tank 1 during operation has a different temperature range (such as -60°C / +150°C).

[0071] This cylindrical part 44 forming a protrusion inside the tank 1 provides a better temperature measurement.

[0072] like Figure 2 As shown and as already pointed out above with respect to the can head of the prior art, the axially outer part 42 of the boss 4 comprises at least two pipes 9, 12 which are arranged radially relative to the axis XX' and are distributed on the periphery of this axially outer part 42 of the boss: these radial pipes 9, 12 open to the outside 14 of the boss 4 and communicate with the channel 8 through their ends inside the boss 4, the channel being closed at its distal end 82, each of these radial pipes being able to receive at their opposite ends 121 opening to the outside 14 any fluid outlet connection element 10 (such as a valve connected to the boss 4, thus also forming the can head) connected to any pressurized fluid supply pipe or hose or a component ensuring a safety function or even a plug.

[0073] As shown in the accompanying drawings, the tank 1 for storing pressurized fluid according to the present invention comprises at least one boss 4 for the outlet of the fluid, and as described above, the functions of the base and the can head are integrated in a single component according to the above characteristics: in addition to the advantages already mentioned above (such as very good resistance to mechanical stress), such a boss 4 also provides axial strength along XX' of the shell during manufacturing, while having good axial positioning.

[0074] The radial member 41 may be bonded or molded to the outer shell 2 of the tank 1 in order to retain the radial force generated on the boss 4 due to the internal pressure of the tank or as Figures 2 to 4 The forces shown are generated between the outer shell 2 and the inner liner 3 , such as a thermoplastic liner or a metal liner, thereby covering the entire inner part of the outer shell 2 of the tank 1 and covering the radial part 41 .

[0075] In a specific embodiment, when the tank 1 has a metal inner liner 3 covering the entire inner part of the outer shell 2 of the tank 1, the radial inner part 41 of the boss 4 can be the inner liner 3 or a part of the liner, and the boss 4 is an integral part of the liner.

[0076] It should be noted that the pressurized fluid in the tank 1 may be NGV (Natural Gas for Vehicles) at a minimum of 250 bar, and hydrogen at a pressure of at least 350 bar but also greater than or equal to 700 bar.

Claims

1. An outlet boss (4) for a pressurized fluid storage tank (1), the outlet boss comprising: - an axial central part (43) which passes through the housing (2) of the tank (1) along the axis XX' and which has at least one channel (8) passing through it, the at least one channel communicating with the internal chamber (5) of the fluid storage tank through its proximal end (81) and the distal end (82) of the at least one channel being closed along its axis XX' in the same direction as the boss (4), a radially inner part (41) which fixes the boss (4) to the outer shell of the tank (1) and is capable of withstanding the pressure of the fluid on the boss (4), and an axially outer part (42) comprising at least one radial fluid outlet duct (9) for said fluid, said at least one radial fluid outlet duct communicating with said channel towards said distal end (82) of said channel (8), Features: - the boss (4) integrally forms a one-piece dispensing head, - the end (121) of the at least one radial duct (9) opens on the exterior (14) of the boss (4) through one of its ends - said at least one radial duct (9) communicating with said channel (8) through its opposite ends is capable of receiving at its ends (121) any fluid outlet connection element (10), - And the channel (8) of the boss (4) constitutes a simple connecting pipe.

2. The outlet boss (4) for a pressurized fluid storage tank (1) according to claim 1, characterized in that: The distal end (82) of the channel (8) of the boss (4) is closed by a safety system (18) operated from the outside (14) and capable of sealing the at least one radial duct (9).

3. The outlet boss (4) for a pressurized fluid storage tank (1) according to claim 1, characterized in that: The distal end (82) of the channel (8) of the boss (4) is closed by a plug (18) operated from the outside (14), and the plug comprises a channel (22) which leads from its distal end (221) to an axial fluid outlet / inlet (7) and from its other opposite proximal end to a duct (23) connected to the distal end (182) of the plug (18), the plug being inserted in a self-sealing system which is capable of opening the connection between the channel (8) and the channel (22) by displacement of the plug (18).

4. The outlet boss (4) for a 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. The outlet boss (4) for a pressurized fluid storage tank (1) according to any one of claims 1 to 4, characterized in that: Its axial central part (43) comprises a cylindrical part (44) which passes through the outer shell (2) of the tank (1) and which itself has at least one passage (8) passing through it, the cylindrical part forming a protrusion beyond the radial inner part (41) of the boss (4).

6. The outlet boss (4) for a pressurized fluid storage tank (1) according to any one of claims 1 to 5, characterized in that: The axial central part (43) comprises at least one second channel (15) axially passing through the central part (43) and suitable for receiving any measuring sensor.

7. The outlet boss (4) for a pressurized fluid storage tank (1) according to any one of claims 1 to 6, characterized in that: Its axially outer part (42) comprises at least two ducts (9, 12) arranged radially relative to said axis XX' and distributed over the periphery of said axially outer part (42).

8. A pressurized fluid storage tank (1), comprising at least one outlet boss (4) for the fluid, characterized in that: The 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 a metal inner lining (3) covering the entire inner part of the outer shell (2) of the tank (1), characterized in that The radially inner part (41) of the boss (4) is part of the inner lining (3), the boss (4) being an integral part of the lining.

Images