Storage device for a pressurized gas

Abstract

A pressurized gas storage system comprising: - a well (2) extending vertically from a ground (4), said well (2) having a side wall (6) and a bottom (8), - at least one tank (10), each tank (10) being elongated in shape defining a longitudinal axis, arranged vertically in the well (2) with a lower end and an upper end, each tank (10) being supported by an upper fixing device (12, 20) and a lower fixing device (12, 20), said upper and lower fixing devices being themselves supported by the side wall (6) and / or by the bottom (8) of the well (2).

Description

[0001] This application concerns a pressurized gas storage device. technical field

[0002] This disclosure relates to the field of pressurized gas storage, for example, hydrogen. Storing gas under pressure is a known process. Storage pressures are on the order of several hundred bars (1 bar being approximately 100 kPa), depending on the gas being stored. Previous technique

[0003] It is known to carry out underground storage of fluids. Thus, for example, document WO2023 / 209079 shows an underground storage system for the storage of fluid comprising a recess having a bottom, a support element having at least one opening suitable for receiving an assembly element, at least one tank having a longitudinal axis, a lower end and an upper end, a first closing means suitable for closing the tank at its lower end, and a second closing means suitable for closing the tank at its upper end, said upper end being suitable for being assembled to the support element by means of the assembly element so that the tank is suspended inside the recess and an axial clearance suitable for absorbing axial thermal expansion of said tank remains between the first closing means and the bottom.

[0004] In the proposed solution, the tanks are suspended within the recess. This places the tank supports under significant load. Furthermore, the proposed solution makes it difficult to access the tanks while they are inside the recess. Any work on a tank typically requires removing it from the recess. Summary

[0005] This disclosure aims to improve the situation. Its purpose is to propose an optimization of a pressurized gas storage system that allows for both easy assembly during system installation and simplified maintenance.

[0006] A pressurized gas storage system is proposed, comprising: a well extending vertically from the ground, said well comprising a side wall and a bottom, at least two tanks, each tank being elongated in shape defining a longitudinal axis, arranged vertically in the well with a lower end and an upper end.

[0007] According to this disclosure, each tank is supported by an upper fixing device and a lower fixing device, said upper and lower fixing devices being themselves supported by the side wall and / or the bottom of the well.

[0008] The features described in the following paragraphs may optionally be implemented, independently of each other or in combination with each other: the tanks are arranged in a ring so as to leave a space free in the center of the well; and / or each lower fixing device and each upper fixing device has a flange; in this variant, a lower / upper fixing device has, for example, an annular piece having a peripheral edge adapted to the cross-section of the side wall of the well and an inner edge with notches, each notch being adapted to receive a tank, and each tank is held in a notch by means of a flange; and / or at least part of the lower and / or upper fixing devices are fixed in the side wall of the well, for example, are pegged into said side wall; and / or the system has a structure with vertical posts resting on the bottom of the well, said structure carrying lower fixing devices and upper fixing devices;and / or the tanks are arranged in the well on several levels; and / or each tank has an inlet / outlet port at its upper end and an outlet / inlet port at its lower end; in this variant, the storage system may further include at least one inlet manifold connected to a plurality of tanks and one outlet manifold connected to said plurality of tanks; and / or the well wall is made watertight by means of a metal liner conforming to the well wall; and / or tanks are fixed to an inner face of a metal liner; and / or the tanks are arranged on several levels, with each level of tanks corresponding to a metal liner and two adjacent metal liners being fixed, for example bolted, to each other;and / or each tank has at each end a mounting bracket, each cooperating with two mounting brackets, one arm of which extends from the well wall into the well to allow a bolted connection between the mounting bracket and the two mounting brackets; and / or the well is closed and equipped with a forced ventilation system creating air circulation around the tanks. Alternatively, a sealed enclosure can be constructed around the tanks and inerting with an inert gas such as nitrogen is carried out around the tanks. Brief description of the drawings

[0009] Other features, details, and advantages will become apparent upon reading the detailed description below and analyzing the attached drawings, on which: Fig. 1 [ Fig. 1 ] shows a storage device in perspective. Fig. 2 [ Fig. 2 ] shows the storage device of the figure 1in longitudinal section. Fig. 3 [ Fig. 3 ] shows a detail of the cross-section of the figure 2 . Fig. 4 [ Fig. 4 ] shows the storage device of the figure 1 top view. Fig. 5 [ Fig. 5 ] shows a cross-sectional detail at an enlarged scale to illustrate fastening devices. Fig. 6 [ Fig. 6 ] shows a detailed view of the figure 1 illustrating more specifically an upper part of the storage device. Fig. 7 ] shows, in perspective, a variant implementation of a storage device. Fig. 8 ] shows in perspective a reservoir used in the storage device of the figure 7 . [ Fig. 9 [shows in perspective the upper part of the tanks of the storage system of the] figure 7 . [ Fig. 10 ] shows in perspective at an enlarged scale the upper part of the storage device of the figure 7 . [ Fig. 11] shows in perspective the lower part of the tanks of the storage system of the figure 7 . Description of the implementation methods

[0010] Reference is now being made to the figure 1A well 2 is visible in the diagram, constructed in soil 4, assumed to be substantially horizontal. Well 2 extends vertically from soil 4. It is a substantially cylindrical well 2, therefore having a vertical, circular cylindrical lateral wall 6 and a bottom 8 assumed to be horizontal, positioned low or below (the opening of well 2 in soil 4 being in a high or upper position). Ideally, well 2 is made watertight to prevent any ingress of water (or other fluid) that could contaminate well 2 or corrode elements placed within it, particularly those described below. Well 2 is advantageously dug in rock and / or consolidation / insulation work is planned to reinforce and / or seal the lateral wall 6 and the bottom 8.

[0011] In the illustrated embodiment, well 2 contains twenty tanks 10. In the illustrated embodiment, all the tanks are similar (although different tanks could be used depending on the requirements). Each tank 10 has a generally cylindrical shape, closed at both ends, with just one inlet / outlet for the gas contained in the tank. Each tank thus has a longitudinal axis which, in its mounted position, is positioned vertically in the well. Preferably, there is a gas inlet (outlet) at the upper end of each tank 10 and a gas outlet / inlet at the lower end of each tank 10. To provide the gas inlet / outlet in each tank, two ports 11inf and 11sup are provided (the term tank is preferred here to the term cylinder because a cylinder generally has only one inlet / outlet).Having two ports in each tank 10 allows them to be coupled as explained below. The storage system can also operate with a single inlet / outlet port per tank 10. Furthermore, if there are two ports, they are preferably located at two opposite ends of the tank 10 in question, but could both be located, for example, on the same upper or lower end.

[0012] The tanks 10 are preferably metallic (steel, for example) and are preferably certified for the gas they are to contain in order to obtain a perfectly leak-proof seal (which is useful when the gas to be stored is hydrogen). They are arranged vertically in well 2 and in a ring around the periphery of the well (though at a distance from the side wall) so as to leave access to the storage system in the center. As can be seen on the figure 4For example, in the center of shaft 2, there is a free space sized (for example, with a diameter greater than one meter) to allow access for a maintenance worker. As illustrated, the tanks 10 are distributed over two levels, each level containing ten tanks 10. In the illustrated configuration, the tanks 10 on one level are aligned with the tanks 10 on the other level, but an offset could be provided.

[0013] For illustrative purposes only and not as a limitation, some dimensions are mentioned below. Shaft 2, for example, may have a diameter of between 2 and 3 meters. Each tank 10 may have a diameter of between 0.2 and 0.6 meters. The depth of shaft 2 varies depending on the number of tank levels and / or the length of the tanks 10. For illustrative purposes only and not as a limitation, the depth of the shaft may be between 50 and 100 meters: such a depth allows for easy access by a person for maintenance and / or upkeep. A tank 10 may have a length on the order of ten meters, for example, between 6 and 18 meters. All these dimensions are purely illustrative and not limiting.

[0014] Each tank 10 is held in place by two (at least) fastening devices, preferably an upper fastening device near the top of the tank (for example, at approximately 3 / 4 of the tank's height, i.e., on the side of the top end) and a lower fastening device near the bottom of the tank (for example, at approximately 1 / 4 of the tank's height, i.e., on the side of the bottom end). Depending on the tank's length and / or the pressure of the gas charged into the tanks, the fastening devices should be designed to accommodate variations in the tank's cross-section and length.

[0015] THE figures 4 to 6They illustrate more specifically the fastening devices used for securing the tanks 10 in the well. Originally, the tanks 10 are either fixed to the side wall 6 of the well, or rest on the bottom 8 of the well 2. For example, it is possible to provide that the tanks 10 of the lower level (or levels) are fixed to a structure resting on the bottom 8 of the well and that the tanks 10 of the upper level (or levels) are fixed to a structure anchored in the side wall 6 of the well.

[0016] THE figures 4 to 6They show a method of attachment used for each tank 10. It is proposed here to use an annular support piece 12. This piece can be cut from a metal plate. The annular support piece 12, for example, has the shape of a U-shaped profile bent to form a ring. It thus has a vertical cylindrical base 14, parallel to the side wall 6 of the well 2, and two horizontal arms 16 extending from the cylindrical base 14 into the well 2. Each of the horizontal arms 16 has recessed housings 18 in the shape of an arc adapted to receive a tank 10. A flange 20, also in the shape of an arc, has, at each end of this arc, a mounting tab 22 extending outwards. Each mounting tab 22 is then attached (preferably bolted) to a mounting plate 24 mounted vertically between the two horizontal arms 16 of the annular support piece 12.To accommodate potential lengthwise expansion of a tank 10, particularly if it is very long, the mounting plate 24 can be mounted (on a rail, for example) so that it can slide longitudinally. To accommodate diameter expansion / contraction of the tank 10, an elastic band (not shown) can be used between the tank 10 and each of its fixing devices; that is, on the one hand, between the tank 10 and each corresponding recess 18, and on the other hand, between the tank 10 and each corresponding flange 20.

[0017] In the illustrated embodiment, an annular support piece 12 is used each time for the upper and lower fixing of a tank 10 and each annular support piece 12 has ten pairs of recessed housings 18. Here we have four similar annular support pieces 12 and each annular support piece 12 corresponds to ten flanges 20.

[0018] In the illustrated embodiment, there are two structures, each with two annular support pieces 12. Posts 26 connect the two parallel annular support pieces 12. Preferably, the posts 26 are all similar and have a height greater than the height of a tank 10. The tanks 10 are mounted on the annular support pieces 12 such that the lower end of each tank 10 is above the lower end of a post 26, and the upper end of each tank 10 is below the upper end of a post 26. The upper and lower ends of the posts 26 are always arranged in the same (horizontal) plane. A post 26 is positioned between each pair of tanks 10, resulting in ten posts 26 per structure in the illustrated example. The number of posts 26 can be adjusted depending on the load.In the illustrated form, the posts 26 are cylindrical tubular posts with a square cross-section and have at each of their ends a support disk 28. The two structures shown are superimposed (. figures 1 to 3 ) and therefore rest (directly for one, indirectly for the other) on the bottom 8 of the well. Depending on the nature of the soil and / or the load to be supported, the bottom 8 can be covered with a suitable screed.

[0019] Several embodiments can be considered here. Instead of using the structures described above, the annular support pieces 12 could be fixed directly to the side wall 6 of the well 2. For example, the cylindrical base 14 of each annular support piece 12 could be fixed to the side wall 6, for instance, using screws anchored into said wall. Instead of providing a single annular support piece 12 common to tanks on the same level, individual fixings can also be considered, for example, clamps with a portion of the clamp fixed to the side wall 6 (two clamps are provided per tank). It is, of course, possible to have different types of fixing devices within the same storage system (lower tanks fixed to a structure resting on the bottom 8 and upper tanks fixed to the side wall 6, for example).

[0020] The proposal here is to connect several tanks 10 together, thus creating a larger capacity tank. In the embodiment illustrated in the drawing, all the tanks 10 on the same level are connected to form a "large" tank. Thus, all the upper ports 11 of the tanks 10 on a level, located at the upper end of a tank 10, are connected to an upper manifold 30 (one upper manifold 30 per level), and all the lower ports 11 of the tanks 10 on a level, located at the lower end of a tank 10, are connected to a lower manifold 32 (one lower manifold 32 per level). All the upper manifolds 30 are then connected to a first main manifold 34, and all the lower manifolds 32 are connected to a second main manifold 36.

[0021] The connections between the tanks 10 are made according to the user's needs. For example, only independent tanks could be used. On the same floor, two (or more) groups of tanks can be planned: in the illustrated example, each floor could have a first lower and then upper manifold connected to five tanks, and a second lower and then upper manifold connected to the other five tanks. It is also possible to connect tanks from two separate floors: for example, connecting two tanks 10 aligned with each other.

[0022] Well 2 is preferably closed at its upper end, ideally with a tight seal. A forced ventilation system can then be installed to control the air intake and exhaust into the well. Analysis of the air exiting the well can help detect any leaks in the storage system.

[0023] It is also possible to consider filling the well with a liquid (water) or a gas, preferably an inert one (such as nitrogen). The presence of water or nitrogen around the tanks, when the stored gas is hydrogen, prevents any risk of the hydrogen coming into direct contact with atmospheric oxygen in the event of a leak. The water or nitrogen in the well thus ensures the safety of the hydrogen storage system. If the well is filled with liquid, the presence of bubbles would also allow for the detection of a gas leak from the tanks (or the network). The liquid would also provide thermal regulation during the filling (exothermic) and emptying (endothermic) of the tanks.

[0024] THE figures 7 to 11show a variant embodiment of a storage device comprising 50 tanks. This storage device is intended to be placed in a well such as well 2 described above.

[0025] An original solution is proposed here: to seal the well wall using a metallic liner 52. This liner 52 has the shape of a circular cylindrical tube. This liner 52 is used, firstly, to seal the well wall, conforming to its shape, and secondly, to secure tanks 50 within the well.

[0026] There figure 7illustrates three assemblies 54, each comprising a stage of tanks 50, in this case a stage of eight tanks 50. As in the previous embodiment, the tanks 50 are arranged parallel to each other at the same height and are arranged in a circle. Each assembly 54 of tanks 50 is intended to be matched by a sleeve 52. Two adjacent sleeves 52 can be bolted together, for example using rings 56 ( figures 9 And 11 ) arranged at each end of a sleeve 52 in a transverse plane (relative to the sleeve 52).

[0027] There figure 8 illustrates a tank 50. It has a circular cylindrical shape, closed at both ends by a base. Each base has a mounting bracket 58 for attaching a tank 50 to the corresponding sleeve 52. As can be seen more clearly on the figure 9For example, the mounting bracket 58 has two arms whose free ends are welded to a tank base, with the base of the mounting bracket 58 extending substantially parallel to the tank base. In the illustrated variant, the base of the bracket is perforated to reduce its weight and facilitate handling.

[0028] For fixing a 50 tank, 60 fixing brackets are provided. One arm of the mounting bracket 60 is welded longitudinally inside a corresponding sleeve 52, and the other arm of the mounting bracket 60 extends into the sleeve 52. By spacing the mounting brackets 60 appropriately, a mounting stirrup 58 can be mounted between two mounting brackets 60. The arms of the mounting brackets 60 extending into the sleeve 52 cooperate with the arms of the mounting stirrup 58 of a tank 50 to allow a bolted connection between the arm of the mounting bracket 60 and the arm of the mounting stirrup 58. Each tank 50 is then secured in this way using its mounting stirrup 58 and a pair of mounting brackets 60 at each end inside the sleeve 52. The tanks 50 are preferably equally distributed inside a 52-fold shirt.Here, for each tank 50, we find an upper and a lower fixing of the tank 50 on the side wall of the well, which here corresponds to the corresponding sleeve 52. At least one of said upper or lower fixings is adapted to allow for the expansion or contraction of the corresponding tank. We note on the... figure 11 that the hole made in the fixing bracket 60 to connect the fixing bracket 60 to the fixing bracket 58 is an oblong hole (which is preferably oriented longitudinally with respect to a longitudinal axis of the corresponding tank 50).

[0029] Depending on the depth of the well, it is possible to house one or more sets of 54 tanks 50. The figures 7 to 11 three sets of 54 tanks are shown by way of illustration and not limitation. It is possible to provide a seal between two adjacent sets of 54 tanks 50.

[0030] There Figure 10illustrates a top closure of a set of 54 tanks. Advantageously, the top face ( Figure 10 ) and the bottom of one or more levels of tank 50 are sealed to create a watertight enclosure. On the Figure 10 , we recognize a transverse closing wall 62 equipped in its centre with a hatch 64.

[0031] Having a sealed enclosure around the 50 tanks allows nitrogen inerting to be carried out inside the enclosure to significantly increase storage safety. Industrial application

[0032] The present technical solution is particularly well suited to the storage of gases under pressure, especially hydrogen but also, for example, oxygen or methane.

[0033] In the system described, each tank is removable independently of the other tanks. Each tank, in each embodiment, can be removed from well 2 individually if intervention on that tank is required.

[0034] The concept presented is highly modular. By adjusting the well's diameter and depth, the overall capacity of the storage system can vary considerably. It is preferable to have several wells with diameters less than 3 meters, for example, rather than one large-diameter well, to optimize the storage system's footprint.

[0035] Mounting tanks using a mechanical fastening system, by clamping or bolting, allows for example partial mounting outside the well and subsequently easier mounting in a well.

[0036] This disclosure is not limited to the example of implementation described above and illustrated in the drawing, only as an example, and the variants mentioned, but it encompasses all the variants that a person skilled in the art may consider within the framework of the protection sought.

Claims

1. A pressurized gas storage system comprising: - a well (2) extending vertically from a ground level (4), said well (2) having a side wall (6) and a bottom (8), - at least two tanks (10), each tank (10) being elongated in shape defining a longitudinal axis, arranged vertically in the well (2) with a lower end and an upper end, characterized in that Each tank (10) is supported by an upper fixing device (12, 20) and a lower fixing device (12, 20), said upper and lower fixing devices being themselves supported by the side wall (6) and / or by the bottom (8) of the well (2).

2. Storage system according to claim 1, characterized in that the reservoirs (10) are arranged in a ring so as to leave a space free in the centre of the well (2).

3. Storage system according to claim 1 or 2, characterized in thatEach lower fixing device (12, 20) and each upper fixing device (12, 20) each includes a flange (20).

4. Storage system according to claim 3, characterized in that a lower / upper fastening device (12, 20) comprises an annular piece (12) having a peripheral edge (14) adapted to the cross-section of the side wall (6) of the well (2) and an inner edge with notches (18), each notch (18) being adapted to receive a reservoir (10), and in that Each reservoir (10) is held in a notch (18) by means of a flange (20).

5. Storage system according to any one of claims 1 to 4, characterized in that at least part of the lower and / or upper fixing devices (12, 20) are fixed in the side wall (6) of the well (2), for example are pegged into said side wall (6).

6. Storage system according to any one of claims 1 to 5, characterized in thatIt features a structure with vertical posts (26) resting on the bottom (8) of the well (2), said structure carrying lower fixing devices and upper fixing devices.

7. Storage system according to any one of claims 1 to 6, characterized in that the reservoirs (10) are arranged in the well (2) on several levels.

8. Storage system according to any one of claims 1 to 7, characterized in that Each reservoir (10) has an inlet / outlet port (11sup) at its upper end and an outlet / inlet port (11inf) at its lower end.

9. Storage system according to claim 8, characterized in that it includes at least one inlet manifold (30) connected to a plurality of tanks (10) and an outlet manifold (32) connected to said plurality of tanks (10).

10. Storage system according to any one of claims 1 to 9, characterized in thatthe well wall (2) is made watertight by means of a metallic liner (52) conforming to the well wall.

11. Storage system according to claim 10, characterized in that reservoirs (50) are fixed on an inner face of a metal sleeve (52).

12. Storage system according to claim 11, characterized in that The tanks (50) are arranged on several levels, in that Each tank level (50) corresponds to a metal liner (52), and in that two adjacent metal sleeves (52) are fixed, for example bolted, together.

13. Storage system according to claim 1 or 2, characterized in thatEach tank (50) has at each end a fixing bracket (58) cooperating with two fixing brackets (60) one arm of which extends from the well wall into the well to allow a bolted assembly between the fixing bracket (58) and the two fixing brackets (60).

14. Storage system according to any one of claims 1 to 12, characterized in that The well (2) is closed and is equipped with a forced ventilation system creating air circulation around the tanks.

15. Storage system according to any one of claims 1 to 12, characterized in that A sealed enclosure is constructed around the tanks, and in that inerting with an inert gas such as nitrogen is carried out around the tanks (50).

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