Apparatus for thermal energy storage and installation for energy conversion and storage

Abstract

An apparatus for thermal energy storage, comprising: a tank (2) containing a hot mass (3) comprising a liquid and configured to absorb or release heat; and a main heat exchanger (4) contained in the pool (2) and immersed in the hot body (3). Main pipes (7, 9) connect the main heat exchanger (4) to a first source (31) of working fluid in a gaseous state or a second source of working fluid in a liquid state. The boiling temperature of the liquid of the hot mass is higher than the condensation / evaporation temperature of the working fluid. There is means for configuring the apparatus in a condensation operating configuration in which a working fluid in gaseous state flows from the first source (31) through the main heat exchanger (4), releases heat to the hot mass and condenses, or in an evaporation operating configuration in which the working fluid in gaseous state flows from the first source (31) through the main heat exchanger (4), releases heat to the hot mass and condenses. A working fluid in a liquid state flows from the second source through the main heat exchanger (4), absorbs heat from the hot mass and evaporates. The liquid is movable in the tank (2) and relative to the main heat exchanger (4), and the ratio of the volume of the tank (2) to the internal volume of the main heat exchanger (4) is greater than one hundred.

Description

Technical Field

[0001] The object of the invention is a device for thermal energy storage and a facility for energy conversion and storage.

[0002] More precisely, the object of the invention is a device capable of accumulating the thermal energy released by a working fluid in a thermal mass contained in a pool of wide dimensions, in which a heat exchanger is immersed, in which the aforementioned working fluid flows. The device according to the invention is capable of condensing or evaporating the working fluid by using a thermal energy exchange with the thermal mass of the pool. Background Art

[0003] In the field of thermal energy storage systems, it is known to use a heat exchanger configured to transfer heat between two fluids. This heat is then accumulated, for example, in one of the two fluids or in a different thermal mass in contact with one of the two fluids.

[0004] There are known heat exchangers that are able to exchange the heat content of two fluids by keeping them separate. These exchangers are provided with a geometric configuration so as to prevent mixing between the two fluids, ie each of the two fluids is confined within a respective closed volume.

[0005] For example, in a plate heat exchanger, two fluid flows at different temperatures exchange their heat content via a stamped surface and are arranged next to each other with countercurrent flow of the fluids.

[0006] The known "shell & tube" type heat exchanger (tube bundle and shell) is a surface heat exchanger consisting essentially of a bundle of tubes placed in a container of substantially cylindrical shape, designated as the shell. The exchanger is traversed by two fluids: one flows on the "tube side" (i.e. inside the tubes) and the other flows on the "shell side" (i.e. in the space defined between the inner surface of the shell and the outer surface of the tubes). For example, when it flows in the heat exchanger, one of the two fluids exchanges latent heat (condensation or evaporation) and the other exchanges sensible heat (heating or cooling). Summary of the invention

[0007] In the art, the Applicant has noticed that in order to make efficient a heat exchanger carrying out condensation or evaporation according to the known technology, i.e. for example a plate heat exchanger or a "shell & tube" type heat exchanger, it is necessary to increase the heat exchange surface or to increase the flow rate of the fluid that is heated or cooled by the condensation or evaporation of the other fluid.

[0008] The Applicant has noted that an increase in the surface within certain limits is inconvenient because it becomes uneconomical. Furthermore, the Applicant has noted that an increase in the flow rate involves an increase in the pressure drop in the duct and then requires the use of more powerful and more expensive pumps configured to act on the heated or cooled fluid and / or requires an increase in the size of the duct and / or the exchanger, thereby increasing the costs (in the case of a heated or cooled fluid at a temperature different from that of the environment) and the disturbances associated with the greater heat exchange of the increased duct with the surrounding environment.

[0009] Furthermore, the Applicant has noticed that if the exchanger is used in the field of a device for thermal energy storage, then destined to be released in a second step, for example for the production of electrical energy, the use of a powerful pump involves the generation of considerable heat by the motor of the pump itself, which interferes with the thermal energy exchange between the two fluids. In fact, the additional heat generated by the pump is also accumulated and is an additional quantity that should be extracted in the electrical energy production step and negatively affects the efficiency of the system.

[0010] The Applicant's object then is to achieve a device for thermal energy storage capable of overcoming the technical drawbacks indicated above.

[0011] In particular, the Applicant's object is to realize a device for thermal energy storage:

[0012] - simpler in structure than known devices;

[0013] - Ability to operate efficiently with reduced power and reduced self-consumption;

[0014] - Essentially unaffected by heat exchange with the surrounding environment and heat generated by fluid handling systems (such as pumps).

[0015] The Applicant has found that the above-mentioned and other objects are achieved by a device for thermal energy storage according to the attached claims and / or according to one or more of the following aspects.

[0016] In a first independent aspect, the invention relates to an apparatus for thermal energy storage, the apparatus comprising:

[0017] a thermal mass comprising a liquid, optionally water, wherein the thermal mass is configured to absorb and store heat or to release heat;

[0018] a pool, the pool including a thermal mass;

[0019] at least one main heat exchanger contained within the pool and immersed in the thermal mass; wherein the liquid is movable within the pool and relative to the at least one main heat exchanger;

[0020] a main conduit connecting the at least one main heat exchanger with a first source of a working fluid in a gaseous state or a second source of the same working fluid in a liquid state;

[0021] Wherein, the boiling temperature of the liquid of the thermal mass body is greater than the condensation / evaporation temperature of the working fluid, and optionally greater than the critical temperature of the working fluid;

[0022] means for configuring the apparatus to be in a condensing operating configuration in which a working fluid in a gaseous state flows from a first source through the at least one main heat exchanger, releases heat to the thermal mass, and condenses while the thermal mass is heated, or in an evaporating operating configuration in which a working fluid in a liquid state flows from a second source through the at least one main heat exchanger, absorbs heat from the thermal mass, and evaporates while the thermal mass is cooled;

[0023] Wherein a ratio of the volume of the tank to the internal volume of the at least one main heat exchanger is greater than one hundred.

[0024] The internal volume of the main exchanger means the volume that is internally delimited in the main exchanger and in which the working fluid is present and in which it flows. The main exchanger means an element suitably designed to exchange heat with a thermal mass in the pool, excluding the pipes that connect this element to a first source of working fluid in the gaseous state and / or a second source of the same working fluid in the liquid state and that may also be partially contained in the pool.

[0025] The Applicant has firstly demonstrated that the device according to the invention allows to receive in the inlet a working fluid in the gaseous state from a first system and to make it available in the liquid phase to a second storage system. The Applicant has demonstrated that the device according to the invention allows to subsequently receive a fluid in the liquid state from a second system and to return it to the first system in the gaseous phase under conditions similar to those under which the device received the fluid. The working fluid in the main heat exchanger exchanges heat with the thermal mass for obtaining these phase changes (latent heat), while the thermal mass heats up or cools down (sensible heat).

[0026] The applicant has firstly demonstrated that the solution according to the invention allows firstly to accumulate heat and then to release it in an efficient manner.

[0027] The Applicant has verified that the solution according to the invention allows to substantially limit the pressure drops due to the movement of the liquid of the thermal mass, since it uses no ducts or through-lamps for the liquid of the thermal mass, or a very limited number of ducts or through-lamps, so that the liquid of the thermal mass is contained in a pool and moves substantially only in said pool.

[0028] Furthermore, the dimensions of the pool relative to those in the main heat exchanger are such as to contain the pressure drop due to the movement of the liquid in the pool, as opposed to what occurs, for example, in a "shell & tube" type exchanger.

[0029] The Applicant has also verified that the structure of the device according to the invention is relatively simple and therefore cost-effective, since the aforementioned conduits and / or lamps (with relative and necessary thermal insulation) are not required to transport the liquid from the thermal mass.

[0030] Furthermore, the Applicant has demonstrated that the substantial absence of ducts allows for a reduction in disturbances associated with heat exchange with the surroundings: all heat exchanged directly or indirectly enters / goes to / from the thermal mass. Other aspects of the invention are described below.

[0031] In one aspect, an apparatus for thermal energy storage includes a working fluid.

[0032] In one aspect, an apparatus for thermal energy storage includes a first source of a working fluid in a gaseous state and / or a second source of the same working fluid in a liquid state.

[0033] In one aspect, the ratio of the volume of the tank to the internal volume of the main heat exchanger is greater than three hundred, optionally greater than five hundred.

[0034] In one aspect, the working fluid has a critical temperature close to ambient temperature, optionally included between 0°C and 100°C.

[0035] In one aspect, the working fluid is selected from the group comprising: carbon dioxide CO2, sulfur hexafluoride SF6, nitrous oxide N2O, hydrocarbons, perfluorinated compounds, water.

[0036] In one aspect, the working fluid is a mixture.

[0037] In one aspect, the working fluid is air.

[0038] In one aspect, the thermal mass is a liquid.

[0039] In one aspect, the liquid is or comprises water.

[0040] In one aspect, the thermal mass comprises oil or a hydrocarbon, such as propane.

[0041] In one aspect, the thermal mass is a mixture comprising the liquid and at least one additive, such as a salt.

[0042] In one aspect, the thermal mass includes the liquid and solid particles or objects such as ice, sand, gravel.

[0043] In one aspect, the pond is natural, such as a river, lake, ocean.

[0044] In one aspect, the pond is artificial, ie the pond is man-made, such as a tank, an artificial lake defined by a dam or a swimming pool.

[0045] In one aspect, the pool is located underground.

[0046] In one aspect, the pool includes lateral walls of concrete or metal.

[0047] In one aspect, the surface of the liquid in the pool is in contact with the atmosphere or with a controlled atmosphere, such as an atmosphere comprising nitrogen.

[0048] In one aspect, the surface of the liquid in the pool is at atmospheric pressure or a pressure slightly greater than atmospheric pressure, for example, at a pressure of a few millibars up to several hundred millibars.

[0049] In one aspect, the pool can have any geometric shape, for example, the pool has a rectangular, square, or circular perimeter in plan view.

[0050] In one aspect, the cell is insulated to limit heat exchange with the external environment.

[0051] In one aspect, the liquid can move naturally in the pool (eg, due to natural flows that exist in a river, lake, or ocean) or by forced circulation.

[0052] In one aspect, a pool defines a closed volume, i.e., the liquid in the pool is substantially always the same. The closed volume is considered closed if there is no substantial mass exchange of the thermal mass between the limits of the volume and the surroundings, and is considered open if there is a possibility of mass exchange.

[0053] In this case, the thermal mass accumulates and stores heat removed from the working fluid in the condensing operating configuration in order to then return that heat to the working fluid in the evaporating operating configuration.

[0054] In one aspect, at least one circulation device is operatively acting on the liquid and is configured to move the liquid in the pool and relative to the at least one main heat exchanger.

[0055] In one aspect, the at least one circulation device comprises a propeller or a pump, such as an axial flow pump or a lift pump or any device for overcoming the small pressure drop that also occurs in the tank due to the presence of the main heat exchanger.

[0056] In an aspect, if the volume is closed, and preferably, but not necessarily, if the pool is artificial, then the at least one circulation device is present.

[0057] In one aspect, the at least one circulation device is configured to create at least one closed liquid circulation path within the closed volume.

[0058] In one aspect, the at least one circulation device is placed in the pool and immersed in the liquid of the pool.Placing the circulation device in the pool allows avoiding the use of any connecting conduits between the circulation device and the pool and thus further limiting the pressure drop.

[0059] In alternative aspects, the at least one circulation device is arranged outside the pool and is in fluid communication with the pool via a conduit. In this case, the most important pressure drop is confined to the conduit.

[0060] The Applicant has then demonstrated that it is possible to use circulation devices with low power and controlled costs and thus limit the thermal disturbances originating from the motors of these circulation devices during their operation.

[0061] In one aspect, the first liquid passage section in the pool is an area orthogonal to the flow direction of the liquid, and the second passage section of the working fluid in the at least one main heat exchanger is an area orthogonal to the flow direction of the working fluid in the main heat exchanger.

[0062] In one aspect, the first pass section is a section of the at least one closed liquid circulation path.

[0063] In one aspect, the ratio of the first pass segment to the second pass segment is greater than one hundred, optionally greater than five hundred.

[0064] In one aspect, the first passage section is greater than 10 m 2 , optionally greater than 20m 2 , optionally greater than 100m 2 .

[0065] In one aspect, the second pass section includes a 0.2 m 2 With 2m 2 between.

[0066] In one aspect, the volume of the pool is greater than 1000 m 3 , optionally greater than 2000m 3 , optionally greater than 10000m 2 .

[0067] In one aspect, the passage velocity of the liquid through the first passage section is lower than 10 m / s, optionally lower than 1 m / s.

[0068] In one aspect, the liquid passes through the first passage section at a velocity greater than 0.01 m / s, optionally greater than 0.05 m / s.

[0069] In one aspect, the passage velocity of the liquid through the second passage section is lower than 1 m / s, optionally lower than 0.5 m / s.

[0070] In one aspect, the liquid passes through the second passage section at a velocity greater than 0.01 m / s, optionally greater than 0.05 m / s.

[0071] In one aspect, at least one conveyor and / or at least one flow diverter is housed in the pool and immersed in the liquid of the pool. The function of the conveyor and / or flow diverter is to allow all liquid in the pool to circulate and / or exchange heat with the heat exchanger. In this way, all liquid surrounds the main heat exchanger or otherwise participates in heat exchange and energy storage.

[0072] In one aspect, the at least one conveyor comprises a cylindrical or hood-shaped body having open opposite ends.

[0073] In an aspect, the at least one main heat exchanger is positioned within the conveyor or at the first open end of the conveyor.

[0074] In an aspect, the at least one circulation device is disposed within the conveyor or at the second open end of the conveyor.

[0075] In one aspect, the at least one flow redirector comprises one or more walls optionally connected to lateral walls defining the pool.

[0076] In one aspect, the walls of the at least one flow redirector are shaped and / or arranged to cause the liquid to form a serpentine trajectory along a closed circulation path.

[0077] In an aspect, the at least one main heat exchanger internally defines at least one passage, optionally a plurality of passages, for a working fluid.

[0078] In an aspect, the at least one main heat exchanger externally delimits one or more passages for a liquid in which the at least one main heat exchanger is immersed.

[0079] In one aspect, the at least one main heat exchanger is of the "once-through" type. In a "once-through" type exchanger, there is no accumulation of working fluid, i.e. the incoming working fluid is equal to the outgoing working fluid. A "once-through" heat exchanger allows condensation and evaporation of a working fluid consisting of a gas mixture (such as, for example, air, but also carbon dioxide, which may not be 100% pure) without separation of the individual components.

[0080] In one aspect, the at least one main heat exchanger comprises at least one bundle of tubes, between which a liquid passes and around which a working fluid passes, within which the working fluid condenses or evaporates.

[0081] In one aspect, the flow of liquid in the reservoir is orthogonal relative to the tube.

[0082] In one aspect, the second passage section of the working fluid is the sum of the sections of the tube.

[0083] In an aspect, the at least one main heat exchanger functions as a condenser in a condensing operating configuration and as an evaporator in an evaporating operating configuration.

[0084] In one aspect, the at least one main heat exchanger comprises a circulation loop having a direct contact condenser and a circulation pump.

[0085] In one aspect, the at least one main heat exchanger comprises: a first main heat exchanger and a second main heat exchanger.

[0086] In one aspect, the first main heat exchanger functions as a condenser in the condensing operating configuration and the second main heat exchanger functions as an evaporator in the evaporating operating configuration.

[0087] In one aspect, each of the at least one main heat exchanger, the first main heat exchanger and the second main heat exchanger may be formed by a plurality of exchangers operating in series or in parallel.

[0088] In one aspect, at least one reservoir, optionally a plurality of tanks, is fluidly connected to the at least one main heat exchanger. The one or more reservoirs are configured to receive and accumulate condensed working fluid originating from the at least one main heat exchanger.

[0089] In one aspect, the reservoirs in the plurality of reservoirs are connected in parallel and / or in series therebetween.

[0090] In one aspect, the at least one reservoir is housed within the pool and at least partially immersed in the liquid of the pool, preferably completely immersed in the liquid of the pool. In this way, the at least one reservoir is protected in the pool, does not occupy additional space, and any undesirable and uncontrolled heat exchange occurs with the thermal mass in which the reservoir is immersed, rather than with the external environment.

[0091] In one aspect, in the condensing operating configuration, the second source serves as the at least one reservoir for receiving and accumulating condensed working fluid.

[0092] In one aspect, in an evaporation operating configuration, the first source comprises a container for a working fluid that evaporates in a gaseous state.

[0093] In one aspect, the at least one main heat exchanger has a first end fluidly connected to a first source or to a container and a second end fluidly connected to a second source or to the at least one reservoir.

[0094] In one aspect, an apparatus comprises said first source or container.

[0095] In one aspect, the apparatus comprises a second source or said at least one reservoir.

[0096] In one aspect, at least one liquid-vapor separator is coupled to the at least one main heat exchanger.The liquid-vapor separator separates the liquid phase of the working fluid in a gaseous state entering or leaving the main heat exchanger.

[0097] In one aspect, the at least one liquid-vapor separator is in fluid communication with the first end of the at least one fluid passage for the fluid on one side and in fluid communication with the first source or with the container on the opposite side. Thus, the liquid-vapor separator is placed at the condenser inlet or at the evaporator outlet.

[0098] In one aspect, the at least one liquid-vapor separator is disposed within the tank and is at least partially, preferably completely, immersed in the liquid of the tank.

[0099] In an alternative aspect, the at least one liquid-vapor separator is located external to the tank.

[0100] In one aspect, the liquid-vapor separator is positioned in an upper position relative to the at least one reservoir.

[0101] In one aspect, the liquid-vapor separator is connected to the at least one reservoir via a corresponding line inside or outside the reservoir.In this way, the liquid phase separated in the upper liquid-vapor separator falls by gravity into the reservoir below.

[0102] In an aspect, the mentioned pipeline has a geometry so as to define a hydraulic containment, ie to ensure that all the steam passes through the main heat exchanger, ie to prevent the steam from bypassing the main heat exchanger.

[0103] In one aspect, there is an auxiliary device comprising at least one auxiliary heat exchanger, optionally comprising a plurality of auxiliary exchangers connected in parallel and / or in series therebetween.

[0104] In an aspect, the at least one auxiliary heat exchanger is in fluid communication on one side with the main heat exchanger or with the liquid-vapor separator and on the opposite side with the first source or with the container.

[0105] The auxiliary heat exchanger is arranged upstream of the at least one main heat exchanger when the device is in the condensing operating configuration for desuperheating the working fluid. The auxiliary heat exchanger is arranged downstream of the at least one main heat exchanger when the device is in the evaporating configuration for superheating the working fluid.

[0106] The device of the invention can then, in a first step, condense and also desuperheat the working fluid and store it in the liquid phase, and in a second step, evaporate and also superheat the working fluid in the gaseous phase, or vice versa.

[0107] In one aspect, the at least one auxiliary heat exchanger has a passage for a working fluid and a passage for a heat carrier configured to exchange heat with the working fluid.

[0108] In one aspect, the heat carrier is different from the thermal mass of the cell.

[0109] In an alternative aspect, the heat carrier is the same thermal mass contained in the cell.

[0110] In one aspect, the at least one auxiliary heat exchanger is in fluid communication with the pool to facilitate desuperheating or superheating the working fluid using the thermal mass or liquid of the thermal mass of the pool.

[0111] In an aspect, the auxiliary device comprises at least one auxiliary reservoir for accumulating the heat carrier, wherein the at least one auxiliary reservoir is in fluid communication with the at least one auxiliary heat exchanger and optionally with the sump.

[0112] In one aspect, the at least one auxiliary reservoir is disposed in the bath and is at least partially, preferably completely, immersed in the liquid of the bath.

[0113] In an alternative aspect, the at least one auxiliary reservoir is located external to the cell.

[0114] In one aspect, the auxiliary system is operatively coupled to the pool and configured to exchange heat with a thermal mass in the pool, preferably where the pool is artificial. The auxiliary system is configured to allow the thermal mass in the pool to exchange heat with the surrounding environment or with an external process in a controlled manner.

[0115] In one aspect, the auxiliary system includes a cooler (cooler) that can remove heat from the thermal mass and release the heat to the surrounding environment or external process or a heater that can release heat to the thermal mass after having collected heat from the surrounding environment or external process.

[0116] In one aspect, the auxiliary system is fluidly connected to the main conduit and is configured to exchange heat with the thermal mass in the pool via the working fluid. The auxiliary system utilizes the working fluid itself to achieve the effect of introducing / extracting heat into / from the thermal mass in a controlled manner.

[0117] In one aspect, the auxiliary system includes: a compressor, an expander or a stack valve, an additional heat exchanger interposed between the compressor and the expander or the stack valve, and a motor-generator mechanically connected to the compressor and / or the expander.

[0118] In one aspect, a pipeline connects the compressor, the additional heat exchanger, the expander or the stacking valve, and the at least one main heat exchanger to form a closed circuit.

[0119] The auxiliary system allows to perform a cooling cycle by introducing electrical energy, using a working fluid and removing heat directly from the working fluid and therefore from the thermal mass contained in the pool. In this particular case, the at least one main exchanger is an integral part of the cooler cycle and performs the function of an evaporator, while the additional exchanger removes the heat. The expander in this case is the tool capable of extracting energy from the working fluid and achieving better cooling efficiency. In this case, the electric motor introduces energy into the system.

[0120] In an aspect, a pump station is arranged between the at least one main heat exchanger and the at least one reservoir.

[0121] In an aspect, the plurality of reservoirs comprises a main reservoir directly connected to the at least one main heat exchanger and at least one storage reservoir, optionally a plurality of storage reservoirs, connected to the main reservoir.

[0122] In one aspect, the storage reservoirs are connected in parallel and / or in series therebetween.

[0123] In one aspect, a pump station is disposed between the main reservoir and the at least one storage reservoir. The pump station is configured to move the working fluid in liquid phase from the main reservoir to the storage reservoir and vice versa.

[0124] In one aspect, the pump station includes valves and / or pumps that allow for movement of fluid from one side to the other or vice versa by using gravity and / or pressure differentials.

[0125] In one aspect, a corresponding line connects the liquid-vapor separator to the main reservoir.

[0126] In one aspect, an additional tank containing a thermal mass is connected to the tank via an additional line, and another heat exchanger operatively acts between the additional line and the second line in a region included between the at least one storage reservoir and the main heat exchanger to exchange heat between the thermal mass and the working fluid.

[0127] In an aspect, a further heat exchanger operatively acts between the additional line and the second line in a region comprised between the at least one storage reservoir and the pump station.

[0128] In one aspect, the other heat exchanger is configured in a condensing operating configuration to supercool the working fluid before accumulating in the at least one storage reservoir until the temperature Te of the working fluid in the liquid phase at the end of condensation is maintained close to the temperature Ts of the working fluid in the gas phase at the beginning of condensation.

[0129] In one aspect, the temperature of the thermal mass in the additional pool is lower than the temperature Ts of the carbon dioxide when condensation begins.

[0130] In an aspect, an additional pump is operable on an additional line, optionally between the at least one storage reservoir and the further heat exchanger.

[0131] In one aspect, the further heat exchanger is located outside the pool.

[0132] In one aspect, in the condensing operating configuration, the thermal mass in the additional pool is pumped toward the pool and passed in another heat exchanger while the working fluid flows toward the at least one storage reservoir.

[0133] In one aspect, in an evaporation operating configuration, the working fluid is heated before evaporating it to bring it close to the evaporation temperature by following a reverse path and then returns to cool a portion of the thermal mass.

[0134] The Applicant has demonstrated that subcooling via an additional tank and the operation of a thermal mass in another heat exchanger allows to significantly increase the density of the working fluid in the reservoir and then reduce the volume and / or number of necessary reservoirs, their size and relative cost.

[0135] In one aspect, the main reservoir is located inside the pool and the at least one storage reservoir is located inside or outside the pool. In this way, the main reservoir and possible storage reservoir inside the pool are thermally isolated from the external environment via the thermal mass. This is useful to maintain any heat exchange with the working fluid in the thermal mass.

[0136] In one aspect, at least one vapor balance line connects the upper portion of the at least one storage reservoir to a point of the main pipe positioned between the first source and the at least one main heat exchanger, or to the first end of the at least one main heat exchanger or to a liquid-vapor separator.

[0137] In an aspect, a regulating valve is operatively acting on said steam balancing line.

[0138] The vapor balance line and regulating valve are configured to "balance" the vapor phase of the working fluid contained in the at least one storage reservoir with the first end of the at least one main heat exchanger. Such balancing is useful to free up space for the liquid as it enters the reservoir, where there would otherwise be a pressure increase due to compression of the vapor phase.

[0139] In one aspect, an apparatus configured to eliminate non-condensable gases is provided.

[0140] In one aspect, the device configured to eliminate non-condensable gases is placed at the upper part of the device, where the non-condensable gases can accumulate. The device can be connected at different points of the device where the working fluid gas phase is present.

[0141] In an aspect, the device configured to eliminate non-condensable gases is operatively connected to the first end of the at least one main heat exchanger or to the liquid-vapor separator or to the vapor balance line.

[0142] In one aspect, the means for configuring the apparatus in a condensing operating configuration or an evaporating operating configuration comprises a manual or actuated valve and a control unit operatively connected to the actuated valve and ultimately to a safety pump and / or valve.

[0143] In an aspect, means for configuring the apparatus in a condensing operating configuration or an evaporating operating configuration operatively act on the main conduit and / or on the at least one main heat exchanger and / or on the first source or reservoir and / or on the second source or container.

[0144] The invention also relates to a plant for energy conversion and storage, comprising a device for thermal energy storage according to one or more of the preceding aspects.

[0145] In one aspect, a facility for energy conversion and storage comprises:

[0146] working fluid other than atmospheric air;

[0147] an enclosure configured to store a working fluid in a gaseous phase;

[0148] at least one compressor in fluid communication with the enclosure;

[0149] at least one expander in fluid communication with the enclosure;

[0150] The device according to at least one of the preceding aspects, wherein the main pipeline of the device is in fluid communication with the compressor and the expander.

[0151] In one aspect, the enclosure is in fluid communication with the inlet of the compressor or with the outlet of the expander, and the apparatus is in fluid communication with the outlet of the compressor or with the inlet of the expander.

[0152] In one aspect, the device is used in an installation as an accumulator of thermal energy generated during compression in a compressor.

[0153] In one aspect, there is provided a main heat exchanger operatively interposed between the device and the compressor and expander, optionally being a thermal accumulator (Thermal Energy Storage—TES) or connected to a thermal accumulator.

[0154] In one aspect, the primary heat exchanger of the apparatus is a secondary heat exchanger of the facility.

[0155] In one aspect, the facility is configured to actuate a closed-cycle thermodynamic conversion between the enclosure and at least one reservoir of the equipment, first in an accumulation configuration in one direction and then in an opposite direction in a discharge configuration; wherein, in the accumulation configuration, the facility stores heat and pressure, and in the discharge configuration, the facility generates energy.

[0156] In an aspect, the facility comprises a floating unit carrying at least an enclosure, the at least one compressor and the at least one expander.

[0157] In one aspect, the reservoir is a river, a lake or an ocean, and the at least one reservoir and the at least one main heat exchanger are immersed in the river, lake or ocean.

[0158] Throughout this specification and the appended claims, reference will be made to the following definitions.

[0159] ■ Thermodynamic Cycle (CT): thermodynamic transformation from point X to point Y, where X and Y coincide; unlike the TTC (Thermodynamic Cyclic Transformation) referenced below, CT has no mass accumulation within the cycle (significant for energetic purposes), whereas TTC usually works between two reservoirs of working fluid, one reservoir being initial and the other being final;

[0160] ■Thermodynamic Cyclic Transformation (TTC): Thermodynamic transformations from point X to point Y and from point Y to point X do not necessarily pass through the same intermediate points;

[0161] ■ Closed CT and / or TTC: no mass exchange with the atmosphere (significant for energy purposes);

[0162] ■Open CT and / or TTC: There is mass exchange with the atmosphere (significant for energy purposes).

[0163] Further features and advantages will become more apparent from the detailed description of a preferred but not exclusive embodiment of a device for thermal energy storage and a facility for energy conversion and storage according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0164] The description will now be illustrated with reference to the accompanying drawings, which are provided for illustration purposes only and are not limiting therefore, in which:

[0165] ■ Figure 1A and Figure 1B shows a device for thermal energy storage according to the invention in a corresponding operating configuration;

[0166] ■ Figure 2 Shows Figure 1A and Figure 1B Variations of the equipment;

[0167] ■ FIG. 3A to FIG. 3D Showing details of the apparatus of the aforementioned figures in corresponding operating steps;

[0168] ■ Figure 4 , Figure 4A and Figure 4B is a TS diagram representing the transformation performed by the device according to the invention;

[0169] ■ Figures 5 to 8 shows parts of corresponding variants of the device for thermal energy storage according to the invention;

[0170] ■ Fig. 9 shows a plant for energy conversion and storage, comprising another variant of the device for thermal energy storage according to the invention;

[0171] ■ Fig.10 An example of a heat exchanger for use in an apparatus according to the invention is shown;

[0172] ■ Fig.11 Shows Figure 1A and Figure 1B Another variation of the device;

[0173] ■ Fig.12 Shows Figure 2 Variations of the equipment;

[0174] ■ Fig.13 It means by Fig.12 TS diagram of the transformation of the device operation. DETAILED DESCRIPTION

[0175] With reference to the accompanying drawings, reference numeral 1 generally indicates an apparatus for storing thermal energy according to the present invention.

[0176] Figure 1A and Figure 1B A first embodiment of an apparatus 1 is shown, comprising a pool 2 containing water 3. The pool 2 shown in this embodiment is of an artificial type, i.e. artificially made, for example with lateral walls and a base of reinforced concrete, with a volume so as to contain a volume equal to about 250 m 3Or a parallelepiped shape and size of a volume of water of 250000 liters. The surface 3a of the water 3 in the pool 2 is in contact with the atmosphere.

[0177] In an embodiment variant, a mixture comprising water and an additive, such as salt or water and solid particles or objects such as ice, sand, gravel, may be used instead of water. In an embodiment variant, the thermal mass comprises oil or hydrocarbons, such as cryogenic propane. In an embodiment variant, the pool 2 may be a metal tank, which may be insulated. In an embodiment variant, the pool 2 may be located underground. In an embodiment variant, the pool 2 may be closed at the top, for example using a deformable membrane or a balloon containing a controlled atmosphere, such as nitrogen.

[0178] The main heat exchanger 4 is contained in the tank 2 so as to be immersed in the water 3. Figure 1A and Figure 1B The main heat exchanger 4 schematically shown in FIG. 4 may be, for example but not exclusively, Fig.10 . In this example, the main heat exchanger 4 comprises a first collector 6 connected to a first pipeline 7, a second collector 8 connected to a second pipeline 9, and a plurality of tubes 5 which are parallel to each other and connect the first collector 6 with the second collector 8. The first pipeline 7 and the second pipeline 9 define the main pipeline of the device 1. In the embodiment shown, the first collector 6 is arranged upward, the second collector 8 is arranged downward, and the tubes 5 are vertical.

[0179] The main heat exchanger 4 is fixed to the tank 2 via suitable anchors of a type known per se and not shown in detail herein. The first collector 6, the second collector 8 and the tube 5 define passages inside the main heat exchanger 4, such that a first end of these passages is in fluid communication with a first line 7 and a second end of these passages is in fluid communication with a second line 9.

[0180] As can be noted, the internal volume of the internal passage of the main heat exchanger 4 is much smaller than the volume of the pool 2, i.e. the volume of the water 3. Preferably, the ratio of the volume of the pool 2 to the internal volume of the main heat exchanger 4 is greater than one hundred. For example, the internal volume of the internal passage is equal to about 1.25 m 3 Or 1250 liters, so that the ratio of the volume of the pool 2 to the internal volume of the main heat exchanger 4 is equal to two hundred. In other variants, the ratio may be greater than three hundred, optionally greater than five hundred.

[0181] Furthermore, the device 1 comprises a liquid-vapor separator 10 arranged in the pool 2 and immersed in the water 3. The liquid-vapor separator 10 can show a structure of a known type, which is therefore not described in detail herein. The liquid-vapor separator 10 is arranged on the first pipeline 7 and is then in fluid communication with the first end of the passage of the main heat exchanger 4 on one side. For example, the liquid-vapor separator 10 is arranged at a height approximately equal to the height of the first collector 6. The liquid-vapor separator 10 is fixed to the pool 2 via suitable anchors of a known type per se and not shown in detail herein. In a variant embodiment, the liquid-vapor separator 10 can also be arranged outside the pool 2, i.e. it can also not be immersed in the water 3.

[0182] The main reservoir 11 is arranged in the pool 2 and immersed in the water 3. The main reservoir 11 can have a structure of known type, so the structure is not described in detail herein. The main reservoir 11 is arranged on the second pipeline 9 and is then in fluid communication with the second end of the passage of the main heat exchanger 4 on one side. The main reservoir 11 is arranged below the liquid-vapor separator 10 and, for example, at a height approximately equal to the height of the second collector 8. A corresponding pipeline 12 connects the liquid-vapor separator 10 to the main reservoir 11. The main reservoir 11 is fixed to the pool 2 via suitable anchors of a known type per se and not shown in detail herein. In the accompanying drawings, this corresponding pipeline 12 is also shown as immersed in the water 3, but can also be located outside the pool 2.

[0183] Furthermore, the device 1 comprises a plurality of storage reservoirs 13, which are arranged in Figure 1A and Figure 1B In the embodiment of the invention, it is also placed in the pool 2 and immersed in the water 3. Figure 2 In a variant of , these storage reservoirs 13 are located outside the tank 2. The storage reservoirs 13 are connected to the terminal end of the second pipeline 9. Figure 1A and Figure 1B In the embodiment, these storage reservoirs 13 are vertical cylindrical elements arranged adjacent to each other and connected in parallel to the second pipeline 9. In a variant embodiment, the storage reservoirs 13 can be connected together in series or in series and in parallel. A control valve or multiple control valves not shown can be arranged on the second pipeline 9, each control valve being associated with one of the reservoirs 13. In addition, the storage reservoirs 13 are fixed to the pool 2 via suitable anchors of a type known per se and not shown in detail herein. Possibly, the storage reservoirs 13 can also be insulated to limit heat exchanges with the external environment (the external environment is the atmosphere if the storage reservoir 13 is located outside the pool 2, or the external environment is water if the storage reservoir 13 is positioned in the pool 2).

[0184] A pump station 14 is operatively positioned on the second pipeline 9 between the main reservoir 11 and the plurality of storage reservoirs 13. An example of the structure of the pump station 14 is shown in FIG. 3A to FIG. 3D 1 is shown in FIG. 1 . In this example, the pump station 14 comprises a check valve 15, a pump 16 and a filter 17 arranged in series on a first pipeline 18, wherein the check valve 15 is located between the pump 16 and the storage reservoir 13, and the filter 17 is arranged between the pump 16 and the main reservoir 11. The check valve 15 is arranged on the delivery side of the pump 16. The pump station 14 comprises a second pipeline 19 bypassing the check valve 15, the pump 16 and the filter 17 and a third pipeline 20 bypassing the check valve 15, the pump 16 and the filter 17. The second pipeline 19 is provided with a corresponding actuating valve 21. The third pipeline 20 is provided with a corresponding actuating valve 22. In addition, an actuating valve 23 is arranged on the first pipeline 18, between the filter 17 and the main reservoir 11 and between the branch of the second pipeline 19 and the branch of the third pipeline 20. Furthermore, an actuating valve 24 is arranged on the first line 18 between the nonreturn valve 15 and the storage reservoir 13 and between the branch of the second line 19 and the branch of the third line 20 .

[0185] A steam balance line 25 provided with a corresponding regulating valve 26 connects the upper part of the storage reservoir 13 to the first line 7. There can also be more than one regulating valve, for example one regulating valve for each of the reservoirs 13. Figure 1A and Figure 1B In the embodiment, the steam balance line 25 is connected to a point of the first line 7 comprised between the main heat exchanger 4 and the liquid-vapor separator 10. In an embodiment variant, the steam balance line 25 can be connected to the first end of the main heat exchanger 4 or as in Figure 2 The liquid-vapor separator 10 is connected to the liquid-vapor separator 10.

[0186] exist Figure 1A and Figure 1B In a non-limiting example, there is also an auxiliary system 27 that is operatively connected to the pool 2 and configured to exchange heat with the water 3 in the pool 2 and the external environment in a controlled manner. The auxiliary system 27 may include a cooler (cooler) that can remove heat from the water 3 and release it to the external environment or a heater that can release heat absorbed from the external environment to the water 3. The auxiliary system 27 may include its own circuit defined by corresponding pipes immersed in the water 3 of the pool 2, or the water of the pool 3 circulates outside the pool 2 and is brought into the auxiliary system 27.

[0187] also, Figure 1A and Figure 1BThe device 1 of the embodiment of the invention comprises a circulation device 28 defined by a propeller 29 moved in rotation by an electric motor 30. The circulation device 28 is contained in the tank 2 and immersed in the water 3 and is configured to create at least one closed circulation path of the water 3 inside the tank 2 so as to move the water 3 in said tank 2 and relative to the main heat exchanger 4 (forced circulation). Figure 1A , Figure 1B and Figure 2 The pool 2 shown in FIG. 2 defines a closed volume and the circulation device 28 always circulates the same water 3 in the closed volume. In this way, the water 3 surrounds the tubes 5 of the heat exchanger 4 and passes through the passages defined between adjacent tubes 5. Figure 1A , Figure 1B and Fig.10 In the embodiment of the present invention, the flow of water 3 in the pool 2 is orthogonal to the above-mentioned pipe 5.

[0188] In a variant embodiment, the circulation device 28 can be any device to overcome the small pressure drop that occurs in the pool 2 due to the interaction of the working fluid in motion with the wall of the pool 2 and / or the interaction of the working fluid in motion in the passage between the tubes 5 of the main heat exchanger 4. For example, the circulation device 28 can be a pump (e.g., an axial flow pump or a lift pump). In a variant embodiment, the circulation device 28 can also be arranged outside the pool 2 and arranged to be in fluid communication with the pool 2 via corresponding conduits.

[0189] The first line 7 is connected to a first source 31 of a working fluid in a gaseous state. For example, the first source 31 is a container containing the working fluid and the working fluid is, for example, carbon dioxide (CO2) in a gaseous state. In a variant embodiment, the working fluid can be air used as a thermal mass together with cryogenic propane.

[0190] The device 1 shown comprises a device 32 configured to eliminate non-condensable gases arranged at the upper part of the device 1, in which device 32 the gas phase of the working fluid is present. Figure 1A and Figure 1B In the exemplary embodiment of , the device 32 for eliminating non-condensable gases is connected to the vapor balance line 25. In an embodiment variant, the device 32 for eliminating non-condensable gases can be connected to the first end of the main heat exchanger 4 or to the liquid-vapor separator 10.

[0191] Furthermore, the device 1 comprises an electronic control unit, not shown, operatively connected to the motor 30, the pump station 14 and ultimately also to other means (valves, pumps, filters, etc.) for configuring the device 1 in a condensing operating configuration or an evaporating operating configuration.

[0192] The boiling temperature T1 of water is greater than the condensation / evaporation temperature T2 of carbon dioxide, in particular greater than the critical temperature of carbon dioxide, so that carbon dioxide exchanges latent heat while water exchanges sensible heat, ie changes its own temperature.

[0193] In the condensing operating configuration, carbon dioxide in the gaseous state flows from the first source 31 through the main heat exchanger 4, releasing heat to the water 3 (water temperature rises) and condenses inside the tube 5 for then accumulating in the storage reservoir 13 in the liquid state ( Figure 1A ). This process Figure 4 The TS graph and Table 1 below are shown.

[0194] Table 1

[0195]

[0196]

[0197] In the evaporation operating configuration, liquid carbon dioxide flows from the storage reservoir 13 through the main heat exchanger 4, where it absorbs heat from the water 3 (water cooling) and evaporates in the tube 5, for then re-entering the container ( Figure 1B ). This process Figure 4 The TS diagram of FIG. 1 and the following Table 2 show. In this configuration, the main reservoir 11 and the reserve reservoir 13 perform the function of a second source of the working fluid in a liquid state.

[0198] Table 2

[0199] E-E' The gas changes from condensation pressure (or from equilibrium pressure with the hot body) to evaporation pressure E'-C' The gas is evaporated C'-B' The gas is superheated

[0200] The water 3 is then a thermal mass that exchanges heat with the carbon dioxide placed in the main heat exchanger 4 and, moreover, stores heat and retains heat in the evaporation configuration to then release heat again to the carbon dioxide in the evaporation configuration.

[0201] In the condensing operation configuration, the pumping unit 14 is configured to move the working fluid that has just condensed and is in a liquid state from the main reservoir 4 toward the storage reservoir 13, that is, from Figure 3A and Figure 3C In the evaporation operation configuration, the pumping unit 14 is configured to move the working fluid in a liquid state from the storage reservoir 13 toward the main reservoir 4, that is, from Figure 3B and Figure 3D The pumping unit 14 can use a pressure difference that facilitates the flow or by means of the pump 16 or also by gravity to move the fluid from point X to point Y, or vice versa. For example, four cases shown in the following Table 3 are determined.

[0202] Table 3

[0203]

[0204]

[0205] The valves of the pumping unit 14 can stack the working fluid from a higher pressure to a lower pressure, and in the case where the upper state of each valve is "saturated" liquid, the lower state of the valve may have a mixture of liquid and vapor, which is to perform operations such as Figure 4 The path from point E to point E' shown in the TS diagram.

[0206] The liquid-vapor separator 10 separates the liquid phase of the carbon dioxide in the gaseous state entering or leaving the main heat exchanger 4. The liquid phase separated in the above-mentioned liquid-vapor separator 10 falls by gravity into the main reservoir 11 below through a corresponding pipeline 12, which has, for example, a geometry such that a hydraulic protection device is defined, i.e. it is ensured that all carbon dioxide in the vapor phase passes through the main heat exchanger 4, i.e. it is prevented that the vapor bypasses the main heat exchanger 4.

[0207] Figure 4A and Figure 4B More precisely, the above reference Figure 4 The content of the description. Figure 4A represents the condensing operating configuration and Figure 4B Indicates the evaporation operating configuration.

[0208] In the condensing operating configuration ( Figure 4A ), water 3 continues to recirculate while carbon dioxide condenses. Therefore, line I-II representing heated water is not fixed, but gradually moves upward to I'-II'. Then, the condensation line CD of carbon dioxide also gradually moves upward to C1-D1, and at the end of condensation, the condensed carbon dioxide is in D1 (in E1, possibly supercooled). Then, the temperature Ts of carbon dioxide when it is all in the vapor phase at the beginning of condensation is lower than the temperature Te of carbon dioxide when it is in the liquid phase at the end of condensation.

[0209] In the evaporation operating configuration ( Figure 4B ), water 3 continues to recirculate while carbon dioxide evaporates. Therefore, the line I'-II" representing the cooled water is not fixed, but gradually moves downward to I-II, and the evaporation line E'-C' of carbon dioxide also gradually moves downward to E'1-C'1.

[0210] In a variant embodiment not shown, the heat exchanger is Fig.10The heat exchanger shown in and described above is of the "once-through" type, i.e. all the working fluid entering from one side leaves from the other side and there is no accumulation. In these variants, the line 12 is not present or the valve is arranged on the line 12. The use of a "once-through" exchanger allows condensation and evaporation of working fluids consisting of gas mixtures (for example air or CO2 is not 100% pure) without separation of the individual components and allows to ensure that the concentration of these components in the condensate that must be evaporated does not change during discharge. Otherwise, if the first component evaporates before the second component, the mixture with the lower concentration of the second component will be evaporated first, thereby enriching the remaining mixture with the second component. For example, if the working fluid is air (78% nitrogen, 20% oxygen, 2% other) and a "once-through" type heat exchanger is not used, the mixture with little oxygen will be evaporated first, so that in the last step there is a very oxygen-rich mixture.

[0211] The steam balance line 25 and the regulating valve 26 are configured to “balance” the vapor phase of the carbon dioxide contained in the storage reservoir 13 through the first end of the main heat exchanger 11 , while the device 32 configured to eliminate the non-condensable gases allows these to be eliminated from points where they could accumulate.

[0212] Along the closed circulation path, the flow of water 3 passes through a first passage section of water (orthogonal to the flow direction) which depends on the size of the tanks 2, their geometry, number and the characteristics of the circulation devices 28. The first passage section is for example equal to 50 m 2 Inside the tube 5 of the main heat exchanger 4, the working fluid passes through the second passage section of the working fluid, which is the sum of the sections of the tube 5. The second passage section is, for example, 5 m 2 Then, the ratio of the first passage section to the second passage section is equal to ten. Furthermore, the passage velocity of the water through the first passage section is low, for example below 1 m / s, for example equal to about 0.05 m / s. The passage velocity of the liquid through the second passage section is for example equal to about 0.1 m / s.

[0213] The device 1 described is capable of receiving a working fluid in the gaseous phase at a temperature close to or above its condensation temperature and making it available in the liquid phase after removing the latent heat extracted from it during the phase change. The system is also capable of performing the reverse operation, namely taking the working fluid in the liquid phase, supplying it with heat to evaporate it (taking this heat from the water 3) and finally superheating it using the sensible heat left in the first step.

[0214] Figure 5Different possible geometries of the pool 2 are shown from above, in this case the pool 2 has a circular shape and also comprises a conveyor 33 immersed in the water 3. In the example shown, the conveyor 33 is defined by a cylindrical body having opposite ends open and communicating with the internal volume of the pool 2. The main axis of the cylindrical body is horizontal. The main heat exchanger 4 is arranged near the first open end of the cylindrical body, while the propeller 29 of the circulation device 28 is positioned near the second open end of the cylindrical body. As shown, this geometry produces two water flows (one flow circulates clockwise and the other flow circulates counterclockwise) that circulate according to two closed circulation paths in the pool 2, and the cylindrical body guides the water 3 of the two closed circulation paths to the main heat exchanger 4. In a variant embodiment not shown, the main heat exchanger 4 and / or the propeller 29 can be arranged in the cylindrical body. In a variant embodiment not shown, the conveyor 33 can also adopt different shapes, such as a hood shape.

[0215] Figure 6 Another variant is shown from above, in which the pool 2 has a rectangular perimeter and is provided with a plurality of flow redirectors 34 immersed in the water 3 of the pool 2 and defined by walls defining a unique closed circulation path with a serpentine trajectory. In particular, the flow redirectors 34 comprise a central wall that essentially divides the pool 2 into two parts, a plurality of walls protruding from the central wall, and a plurality of walls protruding from the lateral walls of the pool 2. The propeller 29 of the circulation device 28 is positioned in an opening defined between a first end of the aforementioned central wall and one of the lateral walls of the pool 2. The main heat exchanger 4 is placed in an opening defined between a second end of the aforementioned central wall and one of the lateral walls of the pool 2.

[0216] Figure 7 A variant of the apparatus 1 is shown, which also includes an auxiliary device 35 arranged between the liquid-vapor separator 10 and the first source 31. The auxiliary device 35 includes a first auxiliary heat exchanger 36A and a second auxiliary heat exchanger 36B arranged in series on the first pipeline 7. Therefore, the first auxiliary heat exchanger 36A and the second auxiliary heat exchanger 36B have a passage in fluid communication with the first pipeline 7 through which the working fluid (carbon dioxide) passes. In addition, the first auxiliary heat exchanger 36A and the second auxiliary heat exchanger 36B have a passage connected to the pool 2, which is passed through by the water 3 of the pool 2. For this purpose, reference is made to Figure 7, the auxiliary line 37 extends upward from the pool 2 to the first auxiliary heat exchanger 36A and the second auxiliary heat exchanger 36B. Below the first auxiliary heat exchanger 36A, the branch of the auxiliary line 37 is connected to the first auxiliary reservoir 38A. Below the second auxiliary heat exchanger 36B, the auxiliary line 37 is connected to the second auxiliary reservoir 38B. An auxiliary pump 39 with a corresponding bypass pipe 40 is arranged on the auxiliary line 37 between the pool 2 and the first auxiliary heat exchanger 36A, and the bypass pipe 40 is provided with a corresponding valve 41. A first auxiliary pump 39A with a corresponding bypass pipe 40A is arranged on the branch, and the bypass pipe 40A is provided with a corresponding valve 41A. A second auxiliary pump 39B with a corresponding bypass pipe 40B is arranged between the second auxiliary heat exchanger 36B and the second auxiliary reservoir 38B, and the bypass pipe 40B is provided with a corresponding valve 41B.

[0217] The first auxiliary reservoir 38A and the second auxiliary reservoir 38B are used to store the water 3 at a different and higher temperature than the water 3 in the pool 2 .

[0218] The first auxiliary heat exchanger 36A and the second auxiliary heat exchanger 36B are arranged above the separator 10 and the main heat exchanger 4 when the device 1 is in the condensing operating configuration, so as to desuperheat the working fluid, that is, to make the temperature of the working fluid approach the condensing temperature ( Figure 4 B).

[0219] The first auxiliary heat exchanger 36A and the second auxiliary heat exchanger 36B are arranged below the main heat exchanger 4 when the device 1 is in the evaporation configuration, so as to superheat the working fluid, that is, to make the temperature of the working fluid approach the inlet temperature of the fluid in the system (A') from a temperature equal to or close to the evaporation temperature (B' or C').

[0220] Figure 7 A first auxiliary reservoir 38A and a second auxiliary reservoir 38B are shown arranged outside the pool 2. In a variant of embodiment not shown, the first auxiliary reservoir 38A and the second auxiliary reservoir 38B are arranged in the pool 2 and immersed in the water 3 or obtained in a chamber obtained in the pool 2. The first auxiliary reservoir 38A and the second auxiliary reservoir 38B may also be thermally insulated for limiting heat exchanges with the surrounding environment (which may be the external environment or the pool 2 if the first auxiliary reservoir 38A and the second auxiliary reservoir 38B are immersed in the water 3 of the pool 2).

[0221] In another variant not shown, the auxiliary device 35 does not work with the water 3 of the pool 2, but with a heat carrier different from the water 3 of the pool 2. In this case, the auxiliary line 37 is connected to one or more auxiliary reservoirs in which the heat carrier is stored at low temperature instead of the pool 2.

[0222] Figure 8 A variation of the device 1 is shown, which shows Figure 1A and Figure 1B The auxiliary system 27 is an alternative to the auxiliary system 27 of the embodiment, and the auxiliary system 27 is configured to exchange heat with the water 3 in the pool 2 and with the external environment in a controlled manner. In this embodiment, the auxiliary system 27 is connected to the first pipeline 7 and the second pipeline 9 and is arranged in parallel with the main heat exchanger 4. The auxiliary system 27 of this embodiment is configured to exchange heat with the water 3 in the pool 2 via the working fluid (carbon dioxide) passing through the main heat exchanger 4. The auxiliary system 27 includes: an auxiliary compressor 42, an auxiliary expander 43 (or alternatively a stacking valve), an additional heat exchanger 44 inserted between the auxiliary compressor 42 and the auxiliary expander 43, and an auxiliary motor 45 mechanically connected to the auxiliary compressor 42 and / or the auxiliary expander 43. The auxiliary compressor 42 is fluidly connected to the first pipeline 7, and the auxiliary expander 43 is fluidly connected to the second pipeline 9. The auxiliary compressor 42 and the auxiliary expander 43 are fluidly connected to each other, and the additional heat exchanger 44 is operatively arranged on the connection between the auxiliary compressor 42 and the auxiliary expander 43. The auxiliary compressor 42, the additional heat exchanger 44, the auxiliary expander 43 and the main heat exchanger 4 form a closed loop. By introducing electrical energy via the auxiliary motor 45, Figure 8 The auxiliary system 27 is able to perform a chiller cycle with the working fluid and remove heat directly from the working fluid and therefore from the water 3 contained in the pool 2. The main heat exchanger 4 acts as an evaporator in the chiller cycle described here.

[0223] In an embodiment variant not shown in the figures, a pump is also present and the auxiliary motor 45 is a motor-generator. The auxiliary system 27 implements a power cycle for generating energy and, in this cycle, the main heat exchanger 4 acts as a condenser.

[0224] In a variant not shown in the drawings but still part of the invention, the apparatus 1 comprises a first main heat exchanger used as a condenser in a condensing operating configuration and a different second main heat exchanger used as an evaporator in an evaporating operating configuration. The first and second main heat exchangers are arranged in parallel with each other. Each of the first and second main heat exchangers has a first end connected to the liquid-vapor separator 10 and the first source 31 fluidly and a second end connected to the main reservoir 11 and the storage reservoir 13 fluidly.

[0225] Furthermore, each of the previously described unique main heat exchanger and the mentioned first and second main heat exchangers described herein may be formed of a plurality of exchangers operating in series or in parallel.

[0226] Fig. 9A facility 100 for energy conversion and storage is shown, which includes and uses a device 1 for accumulating thermal energy according to the invention. The facility 100 may be similar to one of the embodiments described in the publications WO2021191786A1 and WO2021255578A1 in the name of the same applicant. The device 1 according to the invention is used in the facility 100 as a secondary heat exchanger.

[0227] In more detail, the facility 100 shown operates with a working fluid other than atmospheric air, for example selected from the group comprising: carbon dioxide CO2, sulfur hexafluoride SF6, nitrous oxide N2O. The facility 100 is configured to actuate a closed cycle thermodynamic conversion (TTC) first in an accumulation configuration / step in one direction and then in an exhaust configuration / step in the opposite direction, wherein in the accumulation configuration the facility 100 stores heat and pressure and in the exhaust configuration the facility 100 produces electrical energy.

[0228] Reference Fig. 9 , the facility 100 includes an expander, such as a turbine 102 , and a compressor 103 mechanically connected to a motor-generator shaft 104 .

[0229] The facility 100 comprises an enclosure 105 defined by a constant pressure balloon made of a flexible material, such as a PVC-coated polyester fabric. The constant pressure balloon is arranged on a surface and is in contact with atmospheric air on the outside. The constant pressure balloon defines a volume inside it: the volume is configured to contain a working fluid that is at atmospheric pressure or substantially atmospheric pressure, i.e., in pressure equilibrium with the atmosphere during all steps of a cycle operated by the facility 100. The enclosure 105 can also be implemented as a gas meter or a double membrane constant pressure balloon or any other low or zero overpressure gas storage system, wherein the pressure remains constant or substantially constant as the volume of the working fluid changes.

[0230] A first duct 106 is formed between the enclosure 105 and the inlet 103 a of the compressor 103 and between the enclosure 105 and the outlet 102 b of the turbine 102 for fluidly connecting the inner volume of the enclosure 105 with the compressor 103 and the turbine 102 .

[0231] A valve or valve system, not shown, may be operatively positioned on the first conduit 106 for alternately placing the enclosure 105 in fluid communication with the inlet 103 a of the compressor 103 or the outlet 102 b of the turbine 102 .

[0232] The installation 100 comprises a primary heat exchanger 107 which can be selectively placed in fluid communication with the outlet 103b of the compressor 103 or with the inlet 102a of the turbine 102. For this purpose, a second conduit 108 is formed between the inlet 102a of the turbine 102 and the primary heat exchanger 107 and between the outlet 103b of the compressor and the primary heat exchanger 107. The main heat exchanger 107 is a thermal accumulator (thermal energy storage - TES) or is associated with a thermal accumulator.

[0233] A valve or valve system, not shown, is operatively positioned on the second conduit 108 for alternately placing the main heat exchanger 107 in fluid communication with the inlet 102 a of the turbine 102 or the outlet 103 b of the compressor 103 .

[0234] A device 1 of the above type is in fluid communication with a main heat exchanger 107 and is configured to accumulate the working fluid in liquid phase at a temperature close to the critical temperature. The critical temperature of the working fluid is close to the ambient temperature and is preferably comprised between 0°C and 100°C.

[0235] exist Fig. 9 In the embodiment shown in , the first line 7 of the apparatus 1 is connected to the main heat exchanger 107 , so that the liquid-vapor separator 10 remains interposed between the main heat exchanger 4 of the apparatus 1 and the main heat exchanger 107 of the installation 100 .

[0236] In the accumulation configuration, the working fluid in a gaseous state from the enclosure 105 is compressed and heated in the compressor 103. The working fluid then flows through the main heat exchanger 107, which acts as a cooler, to remove some of the heat from the compressed working fluid, cool the working fluid, and accumulate the thermal energy removed from the working fluid. The working fluid then reaches the device 1, where the working fluid (in the main heat exchanger 4) is condensed and accumulated in the storage reservoir 13, while the other thermal energy is accumulated in the water 3 of the pool 2. The working fluid accumulates in the storage reservoir 13 in a liquid state at a temperature close to the critical temperature.

[0237] In the discharge configuration, the working fluid from the reservoir 13 of the device 1 is evaporated (in the main heat exchanger 4) using the heat energy previously accumulated in the water 3 of the pool 2 and sent to the main heat exchanger 107, which now acts as a heater and releases the other heat previously accumulated to the working fluid and heats it. The working fluid then enters the turbine 102 and accumulates again in the enclosure 105 in a gaseous state.

[0238] As from Fig. 9 As can be seen, the apparatus 1 of this embodiment does not comprise an artificial pond, but a natural pond, such as a lake or a river. Fig. 9The river bed is shown in cross section. The water 3 in the river flows naturally and then there is no circulation device. In addition, when the device 1 is immersed in the river itself, the enclosure 105, the turbine 102, the compressor 103, the motor generator 104 and the main heat exchanger 107 can be installed on a floating unit floating on the river (or lake or ocean).

[0239] Fig.11 Another variant of the device 1 of the invention is shown, which differs from Figure 1A and Figure 1B The device 1 in the embodiment of the present invention is a heat exchanger 4, in that the main heat exchanger 4 comprises a heat exchanger 4' as described above combined with a direct contact condenser 46 and a circulation pump 47 arranged on a circulation loop, wherein the direct contact condenser 46 and the heat exchanger 4' are immersed in the water 3 of the pool 2 and the circulation pump 47 is located outside the pool 2.

[0240] In the condensation configuration, carbon dioxide in a gaseous state flows directly from the first source 31 into the direct contact condenser 46 and is condensed by contact with the liquid portion, which is recirculated through the circulation pump 47 and the exchanger 4' and sprayed in the direct contact condenser 46. The liquid portion accumulated in the direct contact condenser 46 is then transported to the storage reservoir 13 via the pumping unit 14.

[0241] In the evaporation operating configuration, liquid carbon dioxide is pumped from the storage reservoir 13 via the pumping unit 14 to the circulation pump 47, circulates through the exchanger 4' and is ejected in the direct contact condenser 46. The gaseous part accumulated in the direct contact condenser 46 is discharged from above the direct contact condenser 46 towards the container of the first source 31.

[0242] Fig.12 Shows Figure 2 A variation of device 1, and Fig.13 Shown by Fig.12 The equipment operates in the condensing operating configuration.

[0243] Fig.12 The equipment includes Figure 2 In addition, an additional tank 110 is connected to the tank 2 via an additional line 111. An additional pump 112 operates on the additional line 111 and the additional line 111 is operatively connected to the second line 9 via a further heat exchanger 113, so that the water flowing in the additional line 111 can exchange heat with the carbon dioxide flowing in the second line 9. The further heat exchanger 113 is arranged between the pump station 14 and the storage reservoir 13. In the additional tank is contained water having a temperature lower than the temperature Ts at which the carbon dioxide starts to condense (see Figure 4A and related descriptions).

[0244] Fig.12A variation of allows to supercool the carbon dioxide in the condensation operating configuration (charging step) so as to keep the temperature Te of the carbon dioxide in the liquid phase at the end of condensation close to the temperature Ts of the carbon dioxide in the gaseous phase at the beginning of condensation.

[0245] For this purpose, in the condensing operating configuration, the water contained in the additional tank 110 is pumped by the additional pump 112 towards the tank 2 and absorbs heat from the carbon dioxide flowing to the reservoir 13 by cooling (subcooling) the water while it enters a further heat exchanger 113 .

[0246] The volume of the reservoir 13 required to store liquid carbon dioxide depends on the density difference between the start of filling (all vapor at the filling start temperature Ts) and the end of filling (all liquid at the filling end temperature Te>Ts). The greater the difference between Te and Ts, the smaller the density difference between liquid and vapor. Then, in order to increase the density difference between liquid and vapor and reduce the volume of the reservoir 13 (and its cost), the difference between Te and Ts can be reduced, and as Fig.13 As shown in Fig.12 The modification of allows this result to be obtained. In fact, the end-of-charging temperature Tes in the case of undercooling (ie in E1) is close to the start-of-charging temperature Ts, and the difference Tes-Ts is lower than Te-Ts, where Te is the end-of-charging temperature in the case of no undercooling (ie in D1).

[0247] Table 4 below shows the Fig.12 The influence of the subcooling of the device operation on the density of carbon dioxide and then on the volume of the reservoir 13. The points indicated in Table 4 are Fig.13 point.

[0248] Table 4

[0249]

[0250]

[0251] By adopting Fig.12 The technical solution (additional tank 110, additional pipeline 111, additional pump 112 and another heat exchanger 113) makes it possible to significantly increase the density of carbon dioxide in the reservoir 13 (about 30% in the example) and then reduce the volume of the required reservoir, its size and relative cost.

[0252] In the evaporation operating configuration (discharge step), the carbon dioxide is heated before evaporation in order to bring it close to the evaporation temperature by following a reverse path and then cooling a part of the water contained in the pool 2 again.

[0253] exist Fig.12In a variant, the reservoir 13 containing carbon dioxide can also be arranged inside the additional pool 110.

[0254] test

[0255] Tests were conducted comparing the device according to the invention with a shell & tube type exchanger, wherein the working fluid mentioned above was located in the inner tube of the shell & tube, while water flowed between the inner tube and the outer casing via a pump placed in a conduit, which introduced the water into the interior of the shell.

[0256] Remove heat (load): 10000 [kwt]

[0257] Accumulation time / energy: 10[h] / 360000[MJ](10[h]*3600[s / h]*10[MWt])

[0258] Thermal mass used: Water

[0259] Temperature increase of water used to store heat: 4[℃]

[0260] In order to store the latent heat in the sensible heat of water and consider heating the water by 4[°C], a filling volume of 21500[m3] of water is required.

[0261] Water velocity in the conduit connected to the housing & tube housing: between 1.5m / s and 2m / s included (acceptable maximum is 3m / s)

[0262] Passing section in the pool: 50[m 2 ]

[0263] Pump efficiency: 80%

[0264] Efficiency of electric motor: 95%

[0265] IHousing & Tube

[0266] II housing & tube has 10 times the flow of case I and equal velocity to that in the connecting conduit.

[0267] III Housing & Tube has 10 times the flow rate of Case I and the maximum acceptable velocity in the conduit. IV The device of the present invention has 10 times the flow rate of Case I.

[0268] I II III IV load [kW] 10000 10000 10000 10000 Water temperature range [℃] 4 0.4 0.4 0.4 flow [kg / s] 597 5972 5972 5972 Velocity in the duct [m / s] 1.80 1.81 2.97 0.12 Catheter size [mm] 650 2050 1600 Catheter section / pass-through section <![CDATA[[m 2 ]]]> 0.33 3.30 2.01 50.00 Pressure Drop [bar] 0.5 0.51 1.36 0.002 HE Loss [bar] 0.05 0.05 0.05 0.05 Pump power [kWe] 43.2 436.4 1109.5 41.0

[0269] As can be seen, in case of 10 times the flow rate, the temperature range (DT) becomes one-tenth, but in the shell & tube solution, the connecting pipe becomes huge and the required power becomes 10 times (case II), or in order to reduce the conduit under acceptable velocity limits, the required power becomes 25 times due to the high pressure drop.

[0270] In the solution according to the invention, there are no tubes but passage sections, allowing to almost completely eliminate the pressure drop generated by the tubes and keep the power consumed equal to the first case but with a temperature range (DT) one tenth (0.4° C. versus 4.0° C.).

[0271] Reference numerals list

[0272] 1 Equipment for thermal energy storage

[0273] 2 Pools

[0274] 3 Water / thermal mass

[0275] 3a Water surface

[0276] 4. 4' Main heat exchanger

[0277] 5 Tubes

[0278] 6 First Collector

[0279] 7 First pipeline

[0280] 8 Second Collector

[0281] 9 Second pipeline

[0282] 10 Liquid-Vapor Separator

[0283] 11. Main storage

[0284] 12 Corresponding pipelines

[0285] 13 Storage Reservoir

[0286] 14 Pumping Station

[0287] 15 Check valve

[0288] 16 Pumps

[0289] 17 Filters

[0290] 18 First pipeline

[0291] 19 Second pipeline

[0292] 20 Third pipeline

[0293] 21, 22, 23, 2 Actuated valve

[0294] 25 Steam balance line

[0295] 26 Control valve

[0296] 27 Auxiliary systems

[0297] 28 Circulation device

[0298] 29 Propeller

[0299] 30 Motor

[0300] 31 First Source

[0301] 32 Devices constructed to remove non-condensable gases

[0302] 33 Teleporter

[0303] 34 Flow diverter

[0304] 35 Auxiliary devices

[0305] 36A First auxiliary heat exchanger

[0306] 36B Second auxiliary heat exchanger

[0307] 37 Auxiliary pipeline

[0308] 38A First auxiliary storage

[0309] 38b Second auxiliary reservoir

[0310] 39 Auxiliary pump

[0311] 39A First auxiliary pump

[0312] 39B Second auxiliary pump

[0313] 40 Bypass pipe

[0314] 40A First bypass pipe

[0315] 40B Second bypass pipe

[0316] 41, 41A, 41B valves

[0317] 42 Auxiliary compressor

[0318] 43 Auxiliary expander

[0319] 44 Additional heat exchanger

[0320] 45 Auxiliary motor

[0321] 46 Direct contact condenser

[0322] 47 Circulation pump

[0323] 100 Facilities

[0324] 102 Expander / Turbine

[0325] 102a Turbine inlet

[0326] 102b Turbine outlet

[0327] 103 Compressor

[0328] 103a Compressor inlet

[0329] 103b Compressor outlet

[0330] 104 Motor-Engine

[0331] 105 Enclosures

[0332] 106 First Pipeline

[0333] 107 Main heat exchanger

[0334] 108 Second Pipeline

[0335] 110 Additional Pool

[0336] 111 Additional pipeline

[0337] 112 Additional pump

[0338] 113 Another heat exchanger

Claims

1. A device for thermal energy storage, comprising: A thermal mass (3), the thermal mass (3) comprising a liquid, optionally water, wherein the thermal mass (3) is configured to absorb and store heat or release heat; A pool (2), the pool (2) comprising a thermal mass (3); at least one main heat exchanger (4), said at least one main heat exchanger (4) being contained in said pool (2) and immersed in said thermal mass (3); wherein the liquid is movable in said pool (2) and relative to said at least one main heat exchanger (4); a main conduit (7, 9) connecting said at least one main heat exchanger (4) to a first source (31) of a working fluid in a gaseous state or to a second source of said same working fluid in a liquid state; wherein the boiling temperature (T1) of the liquid of the thermal mass is greater than the condensation / evaporation temperature (T2) of the working fluid; means for configuring the apparatus (1) to be in a condensing operating configuration or an evaporating operating configuration, in which the working fluid in a gaseous state flows from the first source (31) through the at least one main heat exchanger (4), releases heat to the thermal mass and condenses while the thermal mass is heated, or in which the working fluid in a liquid state flows from the second source through the at least one main heat exchanger (4), absorbs heat from the thermal mass and evaporates while the thermal mass is cooled; Therein, the ratio of the volume of the tank (2) to the internal volume of the at least one main heat exchanger (4) is greater than one hundred, optionally greater than three hundred.

2. The device according to claim 1, wherein: The ratio of the first liquid passage section in the tank (2) to the second working fluid passage section in the at least one main heat exchanger (4) is greater than one hundred.

3. The device according to claim 1 or 2, wherein: The volume of the pool (2) is greater than 1000m 3 , optionally greater than 10000m 3 ; wherein the first passage section is greater than 10m 2 , optionally greater than 100m 2 ; wherein the liquid passes through the first passage section at a speed lower than 10 m / s, optionally lower than 1 m / s.

4. The apparatus of any one of claims 1 to 3, further comprising at least one reservoir (11, 13), optionally a plurality of reservoirs, wherein the at least one reservoir (11, 13) is fluidly connected to the at least one main heat exchanger (4) and is configured to receive and accumulate condensed working fluid from the at least one main heat exchanger (4), and optionally, the at least one reservoir (11, 13) is disposed inside the pool (2) and at least partially immersed in the liquid in the pool (2).

5. The apparatus according to any one of claims 1 to 4, further comprising at least one liquid-vapor separator (10), the at least one liquid-vapor separator (10) being connected to the at least one main heat exchanger (4), optionally, the at least one liquid-vapor separator (10) being disposed inside the pool (2) and at least partially immersed in the liquid of the pool (2).

6. Apparatus according to claim 5 when dependent on claim 4, wherein: The liquid-vapor separator (10) is arranged in the tank (2) at a position above the at least one reservoir (11) and is connected to the at least one reservoir (11) via a corresponding pipeline (12).

7. The device according to any one of claims 1 to 6, wherein: The pool (2) is natural, or wherein, The pool (2) is artificial; wherein the liquid is able to move in the pool (2) naturally or by forced circulation.

8. The apparatus according to any one of claims 1 to 7, further comprising at least one circulation device (28) operatively acting on the liquid and configured to move the liquid in the tank (2) and relative to the at least one main heat exchanger (4); optionally, wherein The at least one circulation device (28) comprises a propeller (29) or a pump.

9. The device according to claim 8, wherein: The at least one circulation device (28) is arranged in the tank (2) and immersed in the liquid in the tank (2).

10. The device according to any one of claims 8 or 9, wherein The tank (2) defines a closed volume such that the at least one circulation device (28) is configured to generate at least one closed liquid circulation path within the closed volume, wherein the first passage section is a section of the at least one closed circulation path.

11. The device according to any one of claims 1 to 10, further comprising at least one conveyor (33) and / or at least one flow diverter (34), wherein the at least one conveyor (33) and / or the at least one flow diverter (34) are housed in the pool (2) and immersed in the liquid in the pool (2).

12. The device according to any one of claims 1 to 11, wherein: The at least one main heat exchanger (4) comprises at least one bundle of tubes (5), wherein the liquid passes between and surrounds the tubes (5), and the working fluid passes in the tubes (5); optionally, wherein the flow of the liquid in the pool (2) is orthogonal to the tubes (5).

13. The device according to any one of claims 1 to 12 comprises an auxiliary device (35), wherein the auxiliary device (35) comprises at least one auxiliary heat exchanger (36A, 36B); the at least one auxiliary heat exchanger (36A, 36B) is arranged upstream of the at least one main heat exchanger (4) when the device (1) is in the condensing configuration, so as to desuperheat the working fluid; the at least one auxiliary heat exchanger (36A, 36B) is arranged downstream of the at least one main heat exchanger (4) when the device (1) is in the evaporating configuration, so as to superheat the working fluid.

14. The device according to claim 13, wherein: The at least one auxiliary heat exchanger (36A, 36B) is in fluid communication with the pool (2) to facilitate desuperheating or superheating of the working fluid using the thermal mass or the liquid of the pool (2).

15. The device according to claim 14, wherein: The auxiliary device (35) comprises at least one auxiliary reservoir (38A, 38B) in fluid communication with the at least one auxiliary heat exchanger (36A, 36B) and the pool (2), and optionally, the at least one auxiliary reservoir (38A, 38B) is disposed in the pool (2) and at least partially immersed in the liquid in the pool (2).

16. Apparatus according to any one of claims 1 to 15, comprising an auxiliary system (27) operatively connected to the pool (2) and configured to exchange heat with the thermal mass in the pool (2), optionally comprising a cooler or a heater.

17. The device according to claim 16, wherein: The auxiliary system (27) is fluidly connected to the main pipeline (7, 9) and is configured to exchange heat with the thermal mass in the pool (2) via the working fluid. Optionally, the auxiliary system (27) includes: a compressor (42), an expander (43) or a stacking valve, an additional heat exchanger (44) inserted between the compressor (42) and the expander (43) or the stacking valve, and a motor-generator (45) mechanically connected to the compressor (42) and / or the expander (43).

18. Apparatus according to claim 4 or according to any one of claims 5 to 17 when dependent thereon, comprising a pump station (14) arranged between the at least one main heat exchanger (4) and the at least one reservoir (11, 13); wherein Optionally, the multiple reservoirs (11, 13) include a main reservoir (11) directly connected to the at least one main heat exchanger (4) and at least one storage reservoir (13) connected to the main reservoir (11), wherein the pump station (14) is arranged between the main reservoir (11) and the at least one storage reservoir (13).

19. Apparatus according to claim 18 when dependent on claim 6, wherein: The respective line (12) connects the liquid-vapour separator (10) to the main reservoir (11).

20. The apparatus according to claim 18 or 19, comprising: at least one steam balancing line (25) connecting the upper part of the at least one storage reservoir (13) to a point of the main pipeline (7, 9) between the first source (31) and the at least one main heat exchanger (4); a regulating valve (26) operatively acting on the at least one steam balancing line (25).

21. Apparatus according to any one of claims 18 to 20, comprising: an additional tank (110), the additional tank (110) containing the thermal mass (3) and connected to the tank (2) via an additional pipeline (111); a further heat exchanger (113), the further heat exchanger (113) operatively acting between the additional pipeline (111) and the second pipeline (9) in an area included between the at least one storage reservoir (13) and the main heat exchanger (4), optionally between the at least one storage reservoir (13) and the pump station (14), for exchanging heat between the thermal mass and the working fluid; the further heat exchanger (113) being configured in the condensing operating configuration to supercool the working fluid before accumulating in the at least one storage reservoir (13) until the temperature (Te) of the working fluid in the liquid phase at the end of condensation is maintained close to the temperature (Ts) of the working fluid in the vapor phase at the beginning of condensation.

22. A facility for energy conversion and storage, comprising: working fluid other than atmospheric air; an enclosure (105), the enclosure (105) being configured to store the working fluid in a gaseous phase; at least one compressor (103), the at least one compressor (103) being in fluid communication with the enclosure (105); at least one expander (102), the at least one expander (102) being in fluid communication with the enclosure (105); The device (1) according to at least one of the preceding claims, wherein the main conduit (7, 9) of the device (1) is in fluid communication with the at least one compressor (103) and the at least one expander (102); wherein the facility (100) is configured to actuate a closed-cycle thermodynamic transformation (TTC) first in one direction in an accumulation configuration and then in an opposite direction in a discharge configuration; wherein, in the accumulation configuration, the facility (100) accumulates heat and pressure, and in the discharge configuration, the facility (100) generates energy.

23. The apparatus according to claim 22, comprising: A floating unit, the floating unit carrying at least the enclosure (105), the at least one compressor (103) and the at least one expander (103); wherein the pool (2) of the device (1) is a river, a lake or an ocean, and the at least one reservoir (11, 13) and the at least one main heat exchanger (4) are immersed in the river, the lake or the ocean.

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