UNDERWATER STORAGE DEVICE FOR COMPRESSED AIR OBTAINED BY A HYDRAULIC PUMP

Abstract

The underwater compressed air storage device comprises at least one underwater compressed air tank, positioned on the floor (7) of a body of water and provided with at least one water outlet opening and at least one inlet opening (11, 13) for a water and air mixture. The tank comprises at least one storage volume (V1) for compressed air provided with two connecting pipes (9, 11) between said volume (V1) and a collection chamber (5) for the water and air mixture, a first pipe (9) located in the upper part of the volume (V1) ensuring the passage of the compressed air into the volume (V1) and a second pipe (11), at a lower altitude than the first pipe (9), ensuring the passage of the water and air mixture into the volume (V1), said tank (V1, V2) also having at least one opening for discharging the degassed water into the body of water. Figure to be published with the abstract: Fig. 1

Description

Title of the invention: DEVICE FOR UNDERWATER STORAGE OF COMPRESSED AIR OBTAINED BY A HYDRAULIC TUMBLER

[0001] The present invention relates to an underwater storage device for compressed air obtained by a hydraulic pump.

[0002] A hydraulic pump is an installation for compressing air drawn into a column of water by the Venturi effect. The height of the water column allows the air to be compressed. The separation of air and water takes place at the bottom of an inverted siphon, in order to obtain air at the hydrostatic pressure generated by the total manometric height. In such installations, the water fall is achieved by pipes several meters, or even tens of meters long. It is thus possible to use compressed air as a source of energy, for example to operate electricity generators or machines. Such installations placed on a body of water are known from US-B-6638024 which describes a device using the bed of a river to receive a pipe for dropping the water and air mixture, the pipe opening near a compressed air collection chamber located in the ocean.Here, storage is limited, the compressed air being returned directly to earth for use. There is therefore only buffer storage achieved in the available volume of the collection chamber.

[0003] The invention proposes a solution for easily storing compressed air produced by an underwater hydraulic pump, with a minimum of parts, at controlled costs.

[0004] For this purpose, the invention relates to an underwater compressed air storage device obtained by a hydraulic pump comprising at least one underwater compressed air tank, positioned on the floor of a body of water and provided with at least one water outlet opening and at least one inlet opening for a water and air mixture produced by the hydraulic pump, characterized in that the tank comprises at least one compressed air storage volume provided with two connecting means between said volume and a chamber for collecting the water and air mixture into which a water and air mixture drop pipe opens, located between the surface of the body of water and the floor of the body of water, a first passage means located in the upper part of the storage volume ensuring the passage of the compressed air into the storage volume from the collection chamber and a second passage means, at an altitude lower than the first passage means,ensuring the passage of the water and air mixture into the storage volume from the collection chamber, said tank also having at , at least one opening for discharging degassed water into the body of water.

[0005] Thus, thanks to the invention, a means of storing compressed air is provided which is directly connected to the compressed air production device, the outlet of the device being directly connected to the tank which ensures, in addition to the collection chamber, the separation of water and air.

[0006] According to advantageous but not mandatory aspects of the invention, such a storage device may comprise one or more of the following characteristics:

[0007] The entire bottom of the storage tank is open.

[0008] A tank comprises several storage volumes connected to each other and of variable capacity.

[0009] A tank comprises several storage volumes connected to each other and of identical capacity.

[0010] Several tanks mounted in series are connected to at least one collection chamber.

[0011] Several tanks mounted in parallel are connected to at least one collection chamber.

[0012] The invention will be better understood and other advantages thereof will appear more clearly on reading the description which follows, given solely by way of non-limiting example and made with reference to the appended drawing in which:

[0013] [Fig-1] is a simplified schematic representation of a storage device in accordance with an embodiment of the invention.

[0014] [Fig.l] is a schematic view of a storage device 1 or reservoir connected to a hydraulic pump. The hydraulic pump comprises a water and air supply reservoir 3 connected by a vertical drop pipe 4 to a collection chamber 5 for the water and air mixture. The pipe 4, which will subsequently also be called a downpipe, extends between the surface 6 and the floor 7 of a body of water. The body of water may be a lake, a dam reservoir, a flooded quarry or the ocean. The length H of the pipe 4 depends on the depth of the body of water and directly determines the air pressure at the outlet of the collection chamber 5, it being understood that the relative pressure increases overall by one bar or 105Pa every 10 meters.

[0015] The collection chamber 5 completely surrounds the end 8 of the drop pipe 4, the latter extending partially inside the chamber 5. According to an advantageous embodiment not illustrated, the end 8 of the drop pipe 4 is flared, in a funnel. In the upper part of the chamber 5, at an altitude higher than that where the end of the drop pipe 4 is located, at least one first connecting means formed here by a pipe 9 connects the chamber 5 to a first volume VI of the storage device 1. In the illustrated embodiment, the device 1 comprises a second volume V2, of smaller capacity. Alternatively, the volumes have the same capacity. The volumes VI and V2 are connected in the upper part by at least one pipe 10, which here is located in the same plane as pipe 9. With such a configuration, a continuity is defined between chamber 5 and volumes VI and V2. It is understood that, as a variant, other volumes can be provided following volume V2 and / or connected by other pipes to chamber 5, this from a connection point other than that of pipe 9 on chamber 5. In other words, several storage volumes, identical or not, can be arranged in series and / or several storage devices 1 in parallel, for example positioned all around chamber 5. Furthermore, the different volumes can be configured in a ring.

[0016] The chamber 5 is also connected to at least one volume V1 by at least one second connecting means, also formed in the example, by a pipe 11. The pipe 11 is positioned under the pipe 9 and at an altitude at least equal to that of the end 8 of the pipe 4. Advantageously, as illustrated, the pipe 11 is at an altitude slightly higher than that of the end 8. In another embodiment, the pipe 11 can be positioned higher but in all cases under the pipe 9. It should be noted that the end 12 of the pipe 11 which opens into the volume V1 is bent and oriented upwards, towards the surface 6 of the body of water. In the embodiment illustrated in [Fig.l], another pipe 13 connects the volumes VI and V2. Alternatively, the different volumes are connected to each other by other means, known per se, than the pipes 11 and 13. Similarly, these pipes 11 and 13 are not bent but straight.The geometric configuration of the pipes 12 and 13 are similar, knowing that their diameters may be different. As for the pipes 9 and 10, the number of pipes 12 and 13 may be different from that illustrated. In all cases, the various volumes VI, V2 of the storage device 1 are connected to each other and to the collection chamber 5 by two types of passage means such as pipes: a first type of pipe 9, 10 de facto forms a continuity of volume in the upper part of the chamber 5 with the volumes VI, V2 and a second type of pipes 11, 13 connects these elements to each other, at an altitude greater than the altitude of the open end 8 of the pipe 4 relative to the floor 7. It should be noted that, in other embodiments, there are no pipes 11, 13, the passage of the water being made directly through the open base of the volumes 5, VI, V2.That being said, the presence of pipes 11 and 13 is advantageous because they allow a longer residence time for the water in the various volumes, therefore a longer degassing time.

[0017] Furthermore, the chamber 5 comprises a guide cone, not illustrated, for the flow of the water and air mixture leaving the end 8 of the pipe 4. This cone is positioned under the end 8, resting on the floor 7 of the body of water. The height of the cone is adapted so that the upper part of the cone is in the vicinity of the pipe 11 while remaining under the end 8, in order to guide the mixture leaving the pipe 4 upwards, which promotes degassing and passage through the pipe 11. The chamber 5 is, before generously, provided with at least one purge, not illustrated, allowing the water remaining in the chamber 5 to be evacuated and therefore the pressure balance to be maintained. Such a purge consists of an orifice made in the wall of the chamber 5.

[0018] The operation of such a storage device 1 is now described with reference to the embodiment of [Fig. 1]. The water and air mixture arrives in the chamber 5 through the open end 8 of the pipe 4, according to the arrow F. At the outlet of the pipe 4, the flow rate of the water and air mixture decreases as one moves away from the end 8 to become almost zero. A funnel shape, not shown, of the end 8 helps to slow down the mixture. The separation between the water and the air is then initiated. The water is evacuated from the chamber 5 to mix with the water in the body of water through the openings, not shown, in the bottom of the chamber 5 in the lower part or, according to a preferred embodiment, through the completely open bottom of the chamber 5. The evacuation is carried out by balancing the hydrostatic pressures between the water in the chamber 5 and that of the body of water, if necessary the purge equipping the chamber coming into action.The air, which is compressed to the pressure prevailing in chamber 5, therefore to that corresponding to the depth at which chamber 5 is placed, here on floor 7 of the body of water, tends to reach the surface of the body of water. As a result, the compressed air is blocked in the upper part of chamber 5. It will naturally flow into the entire available volume, remaining at the initial pressure, therefore it will pass through line 9 to reach volume VI, according to arrow FL If a second volume V2 is, as illustrated, connected to volume VI, the air will also occupy the upper part of volume V2 by passing through line 10. The air will thus occupy all the available volumes.

[0019] A portion of the water and air mixture, not yet degassed, passes from chamber 5 to volume V via pipe 11, according to arrow F2. The orientation of the end 12 of pipe 11 facilitates, according to the illustrated embodiment, the degassing of the water and air mixture and therefore the recovery of the compressed air in volume VI, in the upper part thereof. Alternatively, the end 12 of pipe 11 is not bent. As illustrated, a portion of the non-degassed water and air mixture passes directly from volume V1 to volume V2, the degassing also taking place from the end 14 of pipe 13. In this way, the further one moves away from chamber 5, the less water and air mixture passes into the storage volumes. The storage volumes furthest from chamber 5 are those which contain the least mixture, therefore the least non-degassed water and the most compressed air.

[0020] Openings in the bottom or an open bottom of volumes VI and V2 allow, as for chamber 5, evacuation of water towards the body of water. Thus, by flow of fluids, air and water, in the various constituent elements of the device 1, this at the pressure prevailing in the body of water at the position of the various elements, a progressive filling of volumes VI, V2 with air is ensured, the latter driving the water out of the volumes. The compressed air can be stored for a period of several days, weeks or months, being prevented from escaping towards the surface of the body of water. It is understood that it is appropriate to secure, by known means, the constituent elements of the device 1 and of the chamber 5 to the floor 7 of the body of water and / or to dry land in order to avoid, by rolling and / or pitching movements, any air escape.

[0021] In another embodiment, at least one of the volumes VI, V2 is equipped with at least one discharge pipe, not shown, for the compressed air towards the surface and / or dry land. Such a pipe makes it possible to bring the compressed air at the desired pressure to a place of use and / or storage on the surface, for example a compressed air cylinder. In order to avoid any leakage on the surface, the pipe used to discharge the compressed air towards the surface of the body of water can be closed by a means known per se, for example a valve. In all cases, this closing means is positioned on the surface, on the aerial part of the pipe. In this way, the operation and maintenance of said closing means are facilitated, while avoiding the presence of moving parts underwater.

[0022] Such a device is advantageously modular, the various volumes being adapted and easily connectable to each other according to the storage needs. Furthermore, the device 1 can equip a hydraulic pump already in place in a body of water, the connection of pipes 9 and 11 being made either during underwater work or the chamber 5 is previously provided with means of connection to the pipes 9 and 11. Similarly, if the device originally equips a hydraulic pump, it is possible to add volumes in series or in parallel. Alternatively, several pumps can be connected to a storage device 1 of suitable dimensions. In all cases, the construction of the device 1 is simple and easy to maintain.The absence of a bottom in the various volumes allows for rapid and optimal balancing of pressures between the interior and exterior of the volumes, which means that it is not necessary to use restrictive materials and construction solutions, since all the elements are balanced in terms of internal and external hydrostatic pressure.

Claims

Claims

1. Underwater storage device (1) for compressed air obtained by a hydraulic pump comprising at least one underwater compressed air tank, positioned on the floor (7) of a body of water and provided with at least one water discharge opening and at least one means (11, 13) for passing a water and air mixture produced by the hydraulic pump, characterized in that the tank comprises at least one storage volume (VI) for compressed air provided with two means (9, 11) for passage between said volume (VI) and a collection chamber (5) for the water and air mixture into which a drop pipe (4) for the water and air mixture opens, located between the surface (6) of the body of water and the floor (7) of the body of water, a first passage means (9) located in the upper part of the storage volume (VI) ensuring the passage of the compressed air into the storage volume (VI) from the collection chamber (5) and a second passage means (11),at an altitude lower than the first passage means (9), ensuring the passage of the water and air mixture into the storage volume (VI) from the collection chamber (5), said tank (VI, V2) also having at least one opening for discharging the degassed water into the body of water.,

2. Device according to claim 1, characterized in that the entire bottom of the storage tank (VI, V2) is open.

3. Device according to claim 1, characterized in that a reservoir comprises several storage volumes (VI, V2) connected (10, 13) to each other and of variable capacity.

4. Device according to claim 1, characterized in that a reservoir comprises several storage volumes connected to each other and of identical capacity.

5. . Device according to claim 1, characterized in that several reservoirs mounted in series are connected to at least one collection chamber (5).

6. Device according to claim 1, characterized in that several reservoirs mounted in parallel are connected to at least one collection chamber.

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