Storage device for a gas under pressure

Abstract

A pressurized gas storage system comprising: - a well (2) extending vertically from 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). Abstract figure: Figure 1

Description

Title of the invention: Storage device for a gas under pressure

[0001] The present application relates to a device for storing gas under pressure. technical field

[0002] The present disclosure relates to the field of gas storage under pressure, for example hydrogen. Storing gas under pressure is a known practice. Storage pressures are on the order of a few hundred bars (1 bar being approximately 100 kPa) depending on the gas 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 adapted to receive an assembly element, at least one tank having a longitudinal axis, a lower end and an upper end, a first closing means adapted to close the tank at its lower end, and a second closing means adapted to close the tank at its upper end, said upper end being adapted to be assembled to the support element by means of the assembly element so that the tank is suspended inside the recess and an axial clearance adapted to absorb an 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. The tank support is thus subjected to a heavy load. Furthermore, with the proposed solution, it is not easy to work on the tanks when they are within the recess. Working on a tank most often requires removing the tank from the recess. Summary

[0005] The present disclosure improves the situation. Its purpose is to propose an optimization of a pressurized gas storage system that allows 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 one tank, 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:

[0009] - the tanks are arranged in a ring so as to leave a free space at center of the well; and / or

[0010] - each lower fastening device and each upper fastening device each includes a flange; in this variant, a lower / upper fixing device includes, for example, an annular piece having a peripheral edge adapted to the cross-section of the well's side wall 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

[0011] - at least part of the lower and / or upper fastening devices are fixed in the side wall of the well, for example, are anchored into said side wall; and / or

[0012] - the system has a structure with vertical posts resting on the bottom of the well, said structure bearing lower fixing devices and upper fixing devices; and / or

[0013] - the tanks are arranged in the well on several levels; and / or

[0014] - each reservoir has an inlet / outlet port at its upper end and an inlet / outlet 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

[0015] - the well is closed and is equipped with a forced ventilation system creating a air circulation around the tanks. Brief description of the drawings

[0016] Other features, details and advantages will become apparent from reading the detailed description below and from analyzing the accompanying drawings, in which: Fig. 1

[0017] [Fig.1] shows a storage device in perspective. Fig. 2

[0018] [Fig.2] shows the storage device of [Fig.1] in longitudinal section. Fig. 3

[0019] [Fig.3] shows a detail of the section of [Fig.2]. Fig. 4

[0020] [Fig.4] shows the storage device of [Fig.1] in top view. Fig. 5

[0021] [Fig.5] shows in cross-section a detail at enlarged scale to illustrate fastening devices. Fig. 6

[0022] [Fig.6] shows a detailed view of [Fig.1] illustrating more particularly an upper part of the storage device. Description of the implementation methods

[0023] Reference is now made to [Fig. 1]. This figure shows a well 2 made in soil 4 assumed to be substantially horizontal. The well 2 extends vertically from the soil 4. It is a substantially cylindrical well 2, which therefore has a vertical, circular cylindrical lateral wall 6 and a bottom 8 assumed to be horizontal, positioned low or below (the opening of the well 2 in the soil 4 being in a high or above position). Ideally, the well 2 is made watertight to prevent any ingress of water (or other fluid) that could contaminate the well 2 or corrode elements placed in the well 2, particularly those described below. The 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.

[0024] 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 an overall circular 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, linf and Isup, are provided (the term tank is preferred here to the term cylinder because a cylinder generally only has 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 arranged in pairs. opposite ends of the tank 10 concerned but could both be found for example on the same upper or lower end.

[0025] 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 enclosure (which is useful when the gas to be stored is hydrogen). They are arranged vertically in the well 2 and are positioned in a ring around the periphery of the well (at a distance, however, from the side wall) so as to leave access to the storage system in the center. As can be seen in [Fig. 4], for example, there is a free space in the center of the well 2 which is 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 having ten tanks 10. In the illustrated configuration, the tanks 10 of one level are aligned with the tanks 10 of the other level, but an offset could be provided.

[0026] By way of illustration only and not limitation, some dimensions are mentioned below. Shaft 2 may, for example, have a diameter of between 2 and 3 meters. Each tank 10 may, for example, 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. By way of illustration only and not limitation, the depth of the shaft may be between 50 and 100 meters: such a depth allows easy access for a person to the shaft for maintenance and / or servicing. 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.

[0027] Each tank 10 is held by two (at least) fastening devices, preferably an upper fastening device near the top end of the tank (for example, at about 3 / 4 of the tank's height, i.e., on the side of the top end) and a lower fastening device near the bottom end of the tank (for example, at about 1 / 4 of the tank's height, i.e., on the side of the bottom end). Depending on the length of the tank 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.

[0028] Figures 4 to 6 illustrate in particular 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, the tanks 10 of the lower level (or levels) can be fixed to a structure resting on the bottom 8 of the well and the tanks 10 of the upper floor (or floors above) are fixed to a structure anchored in the side wall 6 of the shaft.

[0029] Figures 4 to 6 show a method of attachment used for each reservoir 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 lateral 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 reservoir 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 bracket 22 is then fixed (preferably bolted) to a mounting plate 24 mounted vertically between the two horizontal arms 16 of the annular support piece 12. To accommodate any possible expansion in length of a tank 10, particularly if it is very long, the mounting plate 24 can be mounted (on a rail, for example) so as to be able to slide longitudinally. For the expansion / contraction in diameter of the tank 10, an elastic band (not shown) can be used between a tank 10 and each of its fixing devices, that is to say, 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.

[0030] 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.

[0031] In the illustrated embodiment, there are two structures, each having two annular support pieces 12. Posts 26 connect the two annular support pieces 12 (which are parallel). The posts 26 are preferably 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 provided between each pair of tanks 10, resulting in ten posts 26 per structure in the illustrated example. Depending on the load, the number of posts 26 can be adjusted.In the illustrated form, the 26 posts are . The cylindrical tubular posts have a square cross-section and a bearing disc 28 at each end. 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.

[0032] 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 example, using screws anchored in 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).

[0033] It is proposed here 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 together to form a "large" tank. Thus, all the upper ports 11sup 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 11linf 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.

[0034] The connections between the tanks 10 are made according to the user's requirements. For example, only independent tanks could be used. On the same floor, two (or more) groups of tanks can be provided: 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.

[0035] Well 2 is preferably closed at its upper end, preferably in a sealed manner. A forced ventilation system can then be provided to control the intake and exhaust of air in the well. Analysis of the air exiting the well can help detect any leaks in the storage system.

[0036] 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. Industrial application

[0037] The present technical solution is particularly well suited to the storage of gas under pressure, in particular hydrogen but also, for example, oxygen or methane.

[0038] In the system described, each tank is removable independently of the other tanks. Each tank can be removed from well 2 individually if intervention on that tank is necessary.

[0039] The concept presented is highly modular. By adapting the well diameter and depth, the overall capacity of the storage system can vary considerably. It is preferable to have several wells with diameters of, for example, less than 3 meters rather than one large-diameter well to optimize the storage system's footprint.

[0040] Mounting the tanks using a mechanical fastening system, by clamping, allows for example partial mounting outside the well and subsequently easier mounting in a well.

[0041] This disclosure is not limited to the example of embodiment described above and illustrated in the drawing, only by way of example, and to 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

Demands

1. 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, 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 tanks (10) are arranged in a ring so as to leave a free space in the center of the well (2).

3. Storage system according to any one of claims 1 or 2, characterized in that each 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 fixing device (12, 20) comprises an annular piece (12) having a peripheral edge (14) adapted to the 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 tank (10), and in that each tank (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 that it has 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 tanks (10) are arranged in the well (2) on several stages.

8. Storage system according to any one of claims 1 to 7, characterized in that each tank (10) has an inlet / outlet port (1 Isup) at its upper end and an outlet / inlet port (1 linf) at its lower end.

9. Storage system according to claim 8, characterized in that it comprises 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 that the well (2) is closed and is equipped with a forced ventilation system creating air circulation around the tanks.

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