WO2024084138A1

WO2024084138A1 - System for generating hydroelectric power and operating method of such a system

Info

Publication number: WO2024084138A1
Application number: PCT/FR2023/051283
Authority: WO
Inventors: Guy Sarremejeanne; Aurélie WOESTELAND; Estelle EMELIE; Aude BASSANESE
Original assignee: Guy Sarremejeanne
Priority date: 2022-10-17
Filing date: 2023-08-21
Publication date: 2024-04-25
Also published as: FR3140913A1

Abstract

The invention relates to a system (2) for generating hydroelectric power comprising a body (4) divided into an upper chamber (8) and a lower chamber (10) by an intermediate floor (6), a first water intake duct (12) connected to an external water source, opening into the upper chamber and provided with a first valve, means (16, 44) for discharging the water present in the upper chamber to the outside, a piston (20) mounted at one end of a rod (22) passing through the intermediate floor (6), a sheath (24) of which one upper end is attached to the intermediate floor and inside of which the rod is able to slide, an annular compression chamber (26) extending the sheath and ending at a downstream end by an injection tip (32), a second water intake duct (34) connected to an external water source, opening into the compression chamber and provided with a second valve (36) and a non-return valve (38), and a hydroelectric turbine (40) supplied with pressurised water by the injection tip.

Description

Title of the invention: hydroelectric energy production system and method of operating such a system

Technical area

[0001] The invention relates to the general field of hydroelectric energy production.

[0002] It concerns more precisely a hydroelectric energy production system - also called a gravity booster - and its operating method.

Prior art

[0003] Hydroelectric energy, or hydroelectricity, is renewable electrical energy which results from the conversion of hydraulic energy into electricity. Typically, the kinetic energy of the water current, natural or generated by a difference in level, is transformed into mechanical energy by a hydraulic turbine, then into electrical energy by a synchronous electric generator.

[0004] Thus, the hydroelectric energy coming from a dam is based on the height of a column of water which provides a turbine placed downstream with a potential energy proportional to this height, called head height. In the case of a so-called “run-of-river” device, it is mainly the kinetic energy provided by the flow of the water current (for example a river) which provides the power necessary to drive the rotation of one or more turbines. In this specific case, the potential energy, taking into account the low gradient of the watercourse, only ensures the flow.

[0005] Known systems for producing hydroelectric energy from a dam have numerous drawbacks, particularly of an ecological nature. The effects of a dam with water retention on ecosystems are multiple: disappearance of plant and animal populations in areas submerged, modification of the water quality of rivers and therefore of aquatic populations in water reservoirs, disruption of river continuity both for sediments and for fauna, modification of hydrology, production of gases with greenhouse due to the degradation of submerged vegetation, modification of the local climate leading to a displacement of populations and a modification of their means of subsistence, danger to aquatic fauna and in particular to fish passages, etc.

[0006] More precisely, a dam accumulates sediments in the reservoir and the filters according to their particle size. Coarse sediments form a landfall at the tail of the reservoir which can propagate further upstream in a solid eddy. The elevation of the bed can then worsen flooding conditions for local residents. Depending on the nature of the watershed, the sediments are likely to fix pollutants present in the water and can be rich in organic matter.

[0007]Whether during emptying or cleaning operations, the environmental impact results from the degradation of the physicochemical quality of the water linked to the suspension of silt. Suspended matter can be a cause of fish mortality by clogging fish gills. In addition, the muddy sediments at the bottom of the reservoir constitute anoxic environments, and therefore reducing. The suspension of silt can therefore be associated with the release of pollutants and oxygen-consuming substances. The deterioration of water quality also results from the release of nitrogenous materials in reduced form, notably ammonia, which is toxic at low concentrations and whose oxidation into nitrites and then nitrates will contribute to the deficit in dissolved oxygen. Finally, fine sediments discharged into a watercourse contribute to clogging the bottom and making it unsuitable for fish reproduction.

[0008] In addition, the hydraulic development modifies the hydrology and stops all or part of the solid inputs coming from upstream. On a natural river, there is a balance between the hydrology of the watercourse, the solid flow and the morphological characteristics of the bed: slope, width, nature of the bottom. There modification of this balance results in a reaction of the morphology of the bed to adapt to these new conditions. The effects of this modification are a deficit in erosive materials and a deficit in transport capacity.

[0009] Furthermore, the lowering of the bed by erosion can cause problems for downstream structures: water intakes that have become too high, lifting of bridge foundations, etc. The lowering of the bed can cross the entire alluvial layer and reach the parent rock: the nature of the bottom and the morphology of the bed are then completely transformed. The lowering of the watercourse leads to the lowering of the accompanying alluvial water table, disrupting the withdrawals from the water table and the vegetation which evolves towards drier forms. Clogging of substrates is particularly detrimental in salmon rivers where it leads to a reduction in the development of benthic microfauna which serves as food for fish. It also limits surfaces favorable to spawning which require well-oxygenated gravel bottoms.

[0010] The impact of the disruption of solid transport by dams appears all the more significant as it generally overlaps with that of other anthropogenic interventions. Practically all human interventions on watercourses contribute in the same direction to a reduction in solid supplies available for the mobility of the bed: extraction of gravel, dikes, land use in watersheds such as agricultural abandonment, restoration of mountain terrain which dries up the source of the materials.

[0011] In a contaminated zone, microparticles of pollutants are transported from the source by runoff and watercourses. They spread throughout the aquatic environment, including reservoirs, lakes, groundwater and oceans. In aquatic ecosystems, they are present in all compartments: they are dissolved in the water column, adsorbed in sediments and accumulated in living organisms. These three compartments exchange particles until an equilibrium is reached. Thus, depending on the chemical conditions, the deposited sediments and suspended matter can either trap the pollutant present in the water column by adsorption, or release it by desorption. [0012] Dam reservoirs accumulate the pollutant brought by the river in two ways: on the one hand, the surface of sediment deposited at the bottom of the reservoir absorbs the pollutant present in the water and, on the other hand, the materials in suspended pollutants will settle and be stored in the reservoir. But, on the other hand, the polluted sediments of the reservoirs can become a source of pollution a) in the event of a change in the quality of the water supplied by the river which can cause the deposited sediments to release the pollutants and b) in the event erosion of the sediments of the reservoir where the polluted materials, then resuspended, will release part of the pollutant into the water to be transported downstream.

[0013] The creation of reservoirs and their associated water networks has an impact on the main parasitic endemics. In hot and humid regions, some of these endemic diseases, which are serious because of their chronicity and the number of people they affect, are caused by pathogens whose vector hosts live in fresh water. These diseases existed in an endemic state before the creation of a reservoir, but the latter has the effect of multiplying the possible sites of vectors and, consequently, of promoting their spread. These main diseases are: malaria, bilharzia and onchocerciasis.

Presentation of the invention

[0014] The object of the invention is therefore to propose a hydroelectric energy production system which does not present the aforementioned drawbacks.

[0015] In accordance with the invention, this goal is achieved thanks to a hydroelectric energy production system comprising at least one energy production module comprising: a cylindrical body divided in the direction of height between an upper chamber and a lower bedroom with an intermediate floor; - at least a first water intake conduit intended to be connected to an external water source, opening into the interior of the upper chamber and provided with a first valve;

- means for evacuating the water present in the upper chamber to the outside;

- a piston which is mounted at an upper end of a rod passing through the intermediate floor and which is capable of sliding vertically inside the upper chamber;

- a sheath, one upper end of which is fixed to the intermediate floor and inside which the rod is able to slide vertically;

- an annular compression chamber extending the sheath at the lower end of which it is fixed, the compression chamber ending at a downstream end with an injection nose;

- at least a second water intake conduit intended to be connected to an external water source, opening into the interior of the compression chamber at a lower end thereof and provided with a second valve and a non-return valve; And

- a hydroelectric turbine supplied with water under pressure through the injection nose of the compression chamber.

[0016] The system according to the invention is remarkable in that it makes it possible to transform the kinetic energy of a watercourse into potential energy on the basis of the application of Archimedes' principle to floating bodies (at unlike traditional hydroelectric production systems called “run-of-river” which only use kinetic energy to produce electricity). In fact, the kinetic energy of the flow of the watercourse only plays a passive role here and in no way determines the power supplied to the hydroelectric turbine. The flow of water only allows the filling of the upper chamber in which a floating body (ie the piston) will rise under the effect of Archimedes' pressure and finally descend once this volume of water has been expelled. of the upper room. More precisely, the piston slides in the compression chamber containing a volume of water which will be evacuated at its end towards the hydroelectric turbine to allow its rotation. The pressure provided by the piston to the volume of water is equivalent to that provided by a column of water on a submerged surface according to the fundamental principle of hydrostatics. The equivalent potential energy provided by the system according to the invention varies as a function of the mass of the piston and the section of the compression chamber.

[0018] Furthermore, the system according to the invention has the particularity, taking into account the reduction in the height of the water column, of using only low reservoir heights to produce the power equivalent to that of a dam. This height is for example of the order of 10 to 15 meters, i.e., for a slope of 2% of a 10 km long watercourse, the possible insertion along this bed of a production system all 500 to 750 meters, or 13 to 20 production systems.

Another feature of the system according to the invention lies in the separation of the hydroelectric production water circuit from that which ensures the traction of the piston. Indeed, the system allows aquatic fauna to migrate downstream without risk of mortality due to its transit in the blades of the turbines thanks to the means for evacuating the water present in the upper chamber or the lower chamber towards the exterior.

[0020] In this way, the system according to the invention makes it possible to ensure the protection of ecosystems and to limit the impacts which, in the case of water retention necessary for the activity of a dam, put into effect danger aquatic fauna, flora, locally the climate and more generally are generators of greenhouse gases.

[0021] According to one embodiment, the intermediate floor comprises at least one closable evacuation valve capable of communicating the upper chamber with the lower chamber when it is in the open position, and the cylindrical body of the module comprises at least one hatch opening inside the lower chamber and opening outwards, the closable evacuation valve and the hatch allowing the water present in the upper chamber to be evacuated to the outside.

[0022] In this embodiment, the lower chamber of the cylindrical body of the module can advantageously contain a floor which is inclined towards the hatch so as to facilitate the evacuation of water.

[0023] According to another embodiment, the cylindrical body comprises at least one closable door opening in the lower part of the upper chamber and opening directly to the outside in order to evacuate the water present in the chamber high towards the outside.

Preferably, the module further comprises means for damping the piston during its vertical descent into the upper chamber.

[0025] Also preferably, the module further comprises means for damping the lateral guidance of the piston during its movement in the upper chamber.

[0026] The rod of the module advantageously opens at an upper end via a pressure balancing valve so as to promote the admission of air and filling in the compression chamber when the piston rises.

[0027] More preferably, the system comprises two energy production modules intended to operate in turn and supplying water under pressure to the same hydroelectric turbine.

[0028] The invention also relates to a method of operating the hydroelectric energy production system as defined above, comprising successively for each module:

- closing the means to evacuate the water present in the upper chamber to the outside;

- opening the first valve and the second valve to fill the upper chamber and the compression chamber respectively with water, the filling of the upper chamber causing a movement of the piston towards the top of the cylindrical body; And

- once the upper chamber is completely filled with water, closing the first valve and the second valve, followed by opening the means to evacuate the water present in the upper chamber to the outside, emptying of the upper chamber causing a downward movement of the piston and its rod, the downward movement of the rod exerting strong pressure on the water contained in the compression chamber which is evacuated through the injection nose in order to to supply pressurized water to the hydroelectric turbine.

Brief description of the drawings

[0029] [Fig. 1] Figure 1 is a perspective view of a hydroelectric energy production system according to one embodiment of the invention.

[0030] [Fig. 2] Figure 2 is a schematic sectional view of the system of Figure 1 in its initial phase.

[0031] [Fig. 3] Figure 3 is a view of the system of Figure 1 in its beginning filling phase.

[0032] [Fig. 4A-4B] Figures 4A-4B are views of the system of Figure 1, respectively in its end of filling and stopping of filling phase.

[0033] [Fig. 5A-5B] Figures 5A-5B are views of the system of Figure 1, respectively in its start and end emptying phase.

[0034] [Fig. 6] Figure 6 is a perspective view of a system according to another embodiment of the invention.

[0035] [Fig. 7] Figure 7 is a system perspective view of a system according to yet another embodiment of the invention.

Description of embodiments [0036] Figure 1 shows in perspective a hydroelectric energy production system 2 according to a first embodiment of the invention.

System 2 consists of one or more energy production modules M, each module comprising a cylindrical body 4 whose longitudinal axis X-X is positioned vertically. This cylindrical body 4 is divided in the height direction by an intermediate floor 6 between an upper chamber 8 and a lower chamber 10.

System 2 also includes one (or more) first water intake conduit 12 which opens inside into the lower part of the upper chamber. This first water intake conduit 12 is intended to be connected to an external water source, typically to the bed of a river, via a first valve 14. The water intake conduit 12 is sized to allow rapid filling of the upper chamber.

[0039] The cylindrical body 4 of the module also comprises at least one hatch 16 which opens inside the lower chamber 10 and which opens towards the outside in order to allow evacuation of the water present in the upper room towards the outside.

The lower chamber 10 contains a floor 18 which is inclined towards the hatch 16 so as to facilitate the evacuation of water to the outside.

The cylindrical body 4 of the module further comprises a piston 20 which is mounted at an upper end of a rod 22 centered on the longitudinal axis X-X and passing through the intermediate floor 6. This piston 20 is capable of sliding vertically from the bottom upstairs inside upper room 8.

More precisely, the rod 22 slides vertically inside a sheath 24 whose upper end is fixed on the intermediate floor 6.

An annular compression chamber 26 extends the sheath from the lower end thereof to which it is fixed. This compression chamber 26 extends along the longitudinal axis XX towards the bottom 28 of the cylindrical body to extend by an elbow 30 which ends at a downstream end by an injection nose 32. [0044] At least a second water intake conduit 34 opens into the interior of the compression chamber 26 at a lower end thereof. This second water intake conduit 34 is intended to be connected to an external water source, typically to the bed of a river, via a second valve 36. It is also provided with a check valve 38.

The system 2 according to the invention also comprises a hydroelectric turbine 40 which is supplied with water under pressure through the injection nose 32 of the compression chamber 26. This hydroelectric turbine 40 is for example a Pelton, Kaplan, Francis, or whatever.

[0046] In addition, the rod 22 opens at an upper end via a pressure balancing valve 42 so as to promote the admission of air and the filling of the compression chamber 26 during the rise of the piston 20.

[0047] In this first embodiment, the intermediate floor 6 comprises a plurality of closable evacuation valves 44 which are able to communicate the upper chamber 8 with the lower chamber 10 when these valves are in the open position (and to prevent any communication between the upper and lower chambers when they are in the closed position).

[0048] More precisely, these evacuation valves 44 are presented here in the form of circular cutouts made in the intermediate floor which are regularly distributed around the longitudinal axis X-X. These circular cutouts are sized to allow the passage of fish present in the river.

[0049] To close them, a circular plate 46 positioned below the intermediate floor and provided with the same circular cutouts 48 can pivot around the longitudinal axis between an angular position in which the respective cutouts of the intermediate floor and the plate 46 are aligned (this position corresponds to the open position of the evacuation valves 44), and an angular position in which the plate 46 closes the cutouts made in the intermediate floor (this position corresponds to the closed position of the evacuation valves). [0050] In connection with Figures 2, 3, 4A, 4B, 5A and 5B, we will now describe an operating method of the hydroelectric energy production system according to this first embodiment.

[0051] Figure 2 represents the system 2 in its initial phase, that is to say that the first valve 14 and the second valve 36 are closed and the piston 20 is in its low position.

[0052] The valves 14 and 36 are then opened to allow the water from the river upstream (not shown) to fill both the compression chamber 26 and the upper chamber 8 through their respective lower ends. This is the start of filling phase shown in Figure 3.

[0053] During this filling, the piston 20 rises towards the ceiling 50 of the body 4 of the system and the rod 22 slides inside the sheath 24. The pressure balancing valve 42 allows the entry of air following the depression which is created inside the sheath so as to promote the filling of the compression chamber 26 and the rise of the piston.

[0054] Figure 4A represents the system in its end of filling phase. In this phase, the piston 20 has reached the level of the ceiling 50 of the body 4 and the sheath 24 is entirely submerged (the compression chamber 26 is entirely filled with water). The first valve 14 and the second valve 36 can then be closed (Figure 4B).

[0055]As shown in Figure 5A, the emptying phase then starts by opening the evacuation valves 44 (here by rotating the circular plate 46 positioned below the intermediate floor 6). The water (possibly with fish) present in the upper chamber 8 of the body 4 empties into the lower chamber 10, then outside the system via the trapdoor 16.

[0056] This flushing system allows the almost instantaneous emptying of the water present in the upper chamber. During this emptying, the piston 20 descends under the effect of its own weight and compresses the water present in the compression chamber 26. The pressurized water is then evacuated through the injection nose 32 to supply the hydroelectric turbine 40. [0057] Once the water has been completely expelled from the system and the compression chamber (Figure 5B), a new cycle can start again.

[0058] Figure 6 represents in perspective a module of a system 2' according to a second embodiment of the invention (the system preferably comprising two identical modules operating one after the other).

[0059] The module of this second embodiment differs from the first in that the cylindrical body 4 comprises at least one closable door 52 which opens in the lower part of the upper chamber 8 of the body 4 and which opens directly towards the outside in order to evacuate the water present in the upper chamber to the outside.

[0060] In other words, in this second embodiment, the water which fills the upper chamber is drained directly to the outside of the system without passing through the lower chamber (draining is thus faster). The lower chamber has no trap door and no sloping floor.

[0061] It will be noted that the closable door 52 is dimensioned to allow the passage of any fish coming from the river and having been introduced into the upper chamber of the system.

[0062] Furthermore, the device (not shown in Figure 6) for closing the door 52 could for example be a gate valve (or any other equivalent device).

[0063] Compared to the first embodiment, the system can be more compact (less bulky in height), due to the absence of water transition through the lower chamber.

Whatever the embodiment, the system can further comprise means for damping the piston 20 during its vertical descent into the upper chamber 8.

[0065] For example, as shown in Figure 6, these damping means can be in the form of a plurality of axial spring shock absorbers 54 mounted on the outer periphery of the intermediate floor 6, regularly distributed around the longitudinal axis XX and bearing against the lower surface of the piston 20.

[0066] Furthermore, whatever the embodiment, the system can include means for damping the lateral guidance of the piston 20 during its movement in the upper chamber 8.

[0067] In the exemplary embodiment of Figure 6, these damping means are in the form of radial spring dampers 56 extending radially and cooperating with the axial spring dampers 54 at the end bottom of the piston. Other 56' spring radial shock absorbers can be mounted at the upper end of the piston.

Whatever the embodiment, the system can comprise two energy production modules as described above intended to operate in turn and supplying water under pressure to the same hydroelectric turbine.

[0069]Thus, in the embodiment of Figure 7, the system 2" comprises two energy production modules Ml, M2 similar to that described in connection with Figure 1 (that is to say with means for evacuating the water present in the upper chamber to the outside which are in the form of evacuation valves made in the intermediate floor and the hatch made in the lower chamber of the module Ml, M2).

[0070] In this embodiment, the respective compression chambers 26 of the two modules Ml, M2 share the same elbow 30 and open towards a hydroelectric turbine 40 which is common.

[0071] In this embodiment, the energy production modules Ml, M2 operate one after the other, that is to say that one of the modules follows the operating method described previously and from once the emptying is completed, the other module begins filling so that the common hydroelectric turbine does not stop operating.

Claims

[Claim 1] System (2; 2'; 2") for producing hydroelectric energy comprising at least one module (M; Ml, M2) for producing energy comprising:

- a cylindrical body (4) divided in the height direction between an upper chamber (8) and a lower chamber (10) by an intermediate floor (6);

- at least a first water intake conduit (12) intended to be connected to an external water source, opening into the interior of the upper chamber (8) and provided with a first valve (14);

- means (16, 44; 52) for evacuating the water present in the upper chamber to the outside;

- a piston (20) which is mounted at an upper end of a rod (22) passing through the intermediate floor (6) and which is capable of sliding vertically inside the upper chamber;

- a sheath (24) whose upper end is fixed to the intermediate floor and inside which the rod (22) is able to slide vertically;

- an annular compression chamber (26) extending the sheath (24) at the lower end of which it is fixed, the compression chamber ending at a downstream end by an injection nose (32);

- at least a second water intake conduit (34) intended to be connected to an external water source, opening into the interior of the compression chamber (26) at a lower end thereof this and provided with a second valve (36) and a non-return valve (38); And

- a hydroelectric turbine (40) supplied with water under pressure through the injection nose of the compression chamber.

[Claim 2] System according to claim 1, in which the intermediate floor (6) comprises at least one closable evacuation valve (44) capable of communicating the upper chamber (8) with the lower chamber (10) when it is in the open position, and the cylindrical body (4) of the module comprises at least one hatch (16) opening inside the lower chamber and opening outwards, the closable evacuation valve and the hatch allowing the water present in the upper chamber to be evacuated to the outside.

[Claim 3] System according to claim 2, in which the lower chamber (10) of the body (4) of the module contains a floor (18) which is inclined towards the hatch (16) so as to facilitate the evacuation of the water.

[Claim 4] System according to claim 1, in which the body (4) comprises at least one closable door (52) opening in the lower part of the upper chamber (8) and opening directly to the outside in order to carry out an evacuation of the water present in the upper chamber to the outside.

[Claim 5] System according to any one of claims 1 to 4, in which the module (M) further comprises means (54) for damping the piston (20) during its vertical descent into the upper chamber (8). ).

[Claim 6] System according to any one of claims 1 to 5, in which the module (M) further comprises means (56) for damping the lateral guidance of the piston (20) during its movement in the upper chamber .

[Claim 7] System according to any one of claims 1 to 6, in which the rod (22) of the module opens at an upper end via a pressure balancing valve (42) so as to promote the air admission and filling in the compression chamber (26) when the piston rises.

[Claim 8] System according to any one of claims 1 to 7, comprising two energy production modules (Ml, M2) intended to operate in turn and supplying water under pressure to the same hydroelectric turbine.

[Claim 9] Method of operating the hydroelectric energy production system according to any one of claims 1 to 8, comprising successively for each module: - closing the means (44; 52) to evacuate the water present in the upper chamber to the outside;

- opening the first valve (14) and the second valve (36) to respectively fill the upper chamber (8) and the compression chamber (26) with water, the filling of the upper chamber causing a movement of the piston (20) towards the top of the body (4) cylindrical; And

- once the upper chamber (8) is completely filled with water, closing the first valve (14) and the second valve (36), followed by opening the means (16, 44; 52) to carry out evacuation water present in the upper chamber towards the outside, the emptying of the upper chamber causing a downward movement of the piston (20) and its rod (22), the movement of the rod downwards exerting a strong pressure on the water contained in the compression chamber (26) which is evacuated through the injection nose (32) in order to supply water under pressure to the hydroelectric turbine (40).