Device and apparatus for storing and releasing thermal energy and energy conversion and storage installation

Abstract

A device (1) for storing and releasing thermal energy, comprising: a reservoir (2) internally delimiting a containing volume (5); a solid inert material (19) provided in the containment volume (5) and configured to allow fluid to flow through the containment volume (5) from the second opening (17) to the first opening (13) or from the first opening to the second opening, where the solid inert material (19) is configured to maintain or release heat released from the fluid to the fluid. A first opening (13) is formed near a first end of the reservoir (2). A tube (16) is positioned within the containment volume (5) and a second opening (17) is formed on a distal end of the tube (16) located near a second end of the reservoir (2) opposite the first end.

Description

TECHNICAL FIELD

[0001] The object of the present invention is a device and equipment for storing and releasing thermal energy, as well as an energy conversion and storage facility.

[0002] More precisely, the object of the present invention is a device and equipment known in English terms as "Thermal Energy Storage" (TES) that can store and release energy in the form of heat, which can be used in different types of facilities such as for storing heat from solar facilities for later reuse. In particular, the device of the object of the present invention is configured to store sensible heat by means of the temperature change of a heat medium.

[0003] DEFINITIONS

[0004] In this specification and the appended claims, the following definitions will be referred to.

[0005] ■ Heat medium: A material for storing thermal energy in the form of sensible heat;

[0006] ■ Solid inert material: A solid material that does not undergo reversible or irreversible chemical reactions with the process fluid;

[0007] ■ Incoherent material: A material formed by bodies / elements that are not connected together, such as stones, gravel, or metal or ceramic spheres / particles, and whose shape is suitable for the container that houses it;

[0008] ■ Coherent material: A material having its own shape, contrary to incoherent material, and whose shape is suitable for the container that houses it;

[0009] ■ Thermocline: A transition and separation layer between a higher temperature zone and a lower temperature zone;

[0010] ■ Closed cycle thermodynamic (CT): A thermodynamic conversion from point X to point Y, where X coincides with Y; different from the TTC (cyclic thermodynamic conversion) referred to below, CT has no mass accumulation within the cycle (significant for energy purposes), while TTC typically operates between two reservoirs of a working fluid, one reservoir being the initial and the other being the final;

[0011] ■ Cyclic thermodynamic conversion (TTC): A thermodynamic conversion from point X to point Y and from point Y to point X, not necessarily through the same intermediate points;

[0012] ■ Closed CT and / or TTC: There is no mass exchange with the atmosphere (significant for energy purposes);

[0013] ■ Open CT and / or TTC: There is mass exchange with the atmosphere (significant for energy purposes). Background Art

[0014] In the field of "thermal energy storage" (TES), systems with sensible heat accumulation are known, which include one or more reservoirs that can accommodate heat storage media. Heat storage media include non-bonded materials, i.e., materials formed by unconnected bodies / elements such as stones, gravels, or metal or ceramic spheres / particles. Heat storage media can also include bonded materials, such as concrete, ceramics, or metals. The heat storage media are surrounded by a working fluid that is transported in the reservoir or in each reservoir through inlets and outlets connected to appropriate pipes. When a hot fluid surrounds the heat storage media, the hot fluid releases heat to the heat storage media, and the heat storage media store the heat. When a cold fluid surrounds the heat storage media, the previously heated heat storage media release heat to the cold fluid, and the cold fluid is heated.

[0015] The published document WO 2011 / 094371 A2 shows a device for storing heat, which includes a cylindrical container having an inner wall and an outer wall and accommodating a plurality of material elements for storing thermal energy. The device includes a first opening and a second opening located on one side of the container and a pipe located inside the container, which is connected to the first opening and has an end spaced from the first opening.

[0016] The published document WO 2013 / 160650 A2 shows an accumulator, which includes a chamber accommodating a plurality of heat storage layers permeable to gas. These heat storage layers are then arranged downward between an inlet and an outlet and are surrounded by an insulator, such that gas flows through these layers from the gas inlet to the gas outlet for transferring thermal energy to or from the storage device.

[0017] The published document JP 2006132806 A shows a module for storing heat, which includes a series of stacked elements provided with undulations.

[0018] The published document JP 2006 038328A shows a device for storing heat, which is provided with a container and elements shaped as plates to be accommodated in the container and separated by spacers.

[0019] The published document EP 2058619 A1 shows a heat accumulator formed by a liquid reservoir surrounded by a vacuum-sealed insulating layer. Summary of the Invention

[0020] In this field, the applicant aims to achieve devices and equipment for storing and releasing thermal energy, which ensure better performance compared to known systems in terms of energy, with respect to mechanical aspects, and from the perspective of cost optimization.

[0021] In particular, the applicant aims to achieve a special structure of a reservoir or each reservoir, which houses a heat storage medium and allows a previous hot fluid to flow through the reservoir or each reservoir, and then allows a cold fluid to flow through the reservoir or each reservoir, aiming to release heat to and absorb heat from the heat storage medium.

[0022] What the applicant has found is that the above object and other objects can be achieved by means and / or devices according to the appended claims and / or according to one or more of the following aspects.

[0023] In a first independent aspect, the present invention relates to a device for storing and releasing thermal energy, the device comprising:

[0024] a reservoir that internally defines a receiving volume;

[0025] a first conduit configured to fluidly connect the receiving volume to a first pipeline outside the reservoir, wherein the first conduit has a first opening that leads to the receiving volume at a first end of the reservoir;

[0026] a second conduit configured to fluidly connect the receiving volume to a second pipeline outside the reservoir; wherein the second conduit has a second opening that leads to the receiving volume at a second end of the reservoir opposite the first end;

[0027] a solid inert material disposed in the receiving volume and configured to allow a fluid to flow through the receiving volume from the first opening to the second opening or from the second opening to the first opening;

[0028] wherein the solid inert material is configured to store / hold heat released from the fluid or release heat to the fluid during the conveyance of the fluid.

[0029] In a second aspect according to the first aspect, the reservoir is configured to optionally operate in a vertical position such that the first end of the reservoir is disposed at the bottom and the second end of the reservoir is disposed at the top;

[0030] wherein the first conduit and the second conduit open outwardly at the first end of the reservoir, and the first external pipeline and the second external pipeline are located near the first end;

[0031] wherein the second conduit includes a tube at least partially located within the receiving volume or is connected to the tube, and the second opening is formed at the end end of the tube near the second end of the reservoir such that the receiving volume is delimited by the radially inner surface of the reservoir and the radially outer surface of the tube.

[0032] In one aspect, the solid inert material is a non - cohesive material, i.e., comprising a plurality of bodies or elements not joined together, such as stones or gravel or metal spheres, say iron or ceramic.

[0033] In one aspect, the solid inert material is a cohesive material in which defined channels and / or chambers are present. For example, the cohesive material is a unique mass having chambers, such as to obtain good heat exchange characteristics. Alternatively, the solid inert material comprises a plurality of blocks that support one another, and each of these blocks has a chamber, such as to obtain good heat exchange characteristics.

[0034] In one aspect, the Biot number of the solid inert material is less than 1, preferably less than 0.1.

[0035] The Biot number is a dimensionless quantity used in the calculation of heat transfer and provides an exponent of the ratio between the thermal resistance within the body and the thermal resistance within the surface of the body. Depending on this ratio of the thermal gradient applied to its surface, it is determined whether the temperature within the body will vary significantly spatially as the body is heated or cooled over time.

[0036] The applicant has verified that if the inert solid is a non - cohesive material, a vertical orientation of the reservoir in which the inlet is at the bottom and the outlet is at the top or the inlet is at the top and the outlet is at the bottom allows the non - cohesive material to arrange itself such that it occupies the entire transverse cross - section of the reservoir, so that it does not leave empty spaces through which the fluid would otherwise travel without heat - exchanging with the non - cohesive material, thus extending the thermocline. In fact, if the reservoir is horizontally oriented with the inlet and the outlet on opposite sides but at the same level, the non - cohesive material may not occupy the entire transverse cross - section of the reservoir relative to the direction of fluid movement, such that the upper part of the reservoir may be empty, and fluid conveyance through this part will not allow effective heat exchange with the non - cohesive material. Moreover, even in the case where an internal buffer is installed in a horizontally - oriented reservoir, this phenomenon may be reduced but not eliminated.

[0037] The applicant has verified that positioning the tube inside the reservoir allows such a tube with a reduced wall thickness to be achieved, thus saving materials, since the pressure of the fluid inside the tube is balanced with the pressure of the fluid in the accommodation volume, i.e., around the tube. Moreover, considering the reduced thickness, the inner tube also has a reduced thermal inertia. This allows the front to remain steep due to the rapid heating of the inner tube relative to the heat mass.

[0038] The internal positioning of the tube prevents the hot fluid flowing through the tube from dissipating heat to the external environment.

[0039] In a third aspect according to the first or second aspect, the reservoir includes an outer housing configured to withstand fluid pressure, an inner housing that supports a radially inner surface and defines a receiving volume, and a thermal insulation material placed in a chamber defined between the outer housing and the inner housing; wherein, the inner housing has channels for allowing fluid to also fill the chamber; wherein, if the inert material is a heated and cooled solid, the inner housing has a thermal inertia similar to that of the solid inert material, such that the inner housing and the solid inert material are heated together or such that they have a limited temperature difference during heating (filling) and cooling (discharging). These channels are placed at the same pressure level such that the chamber is in pressure equilibrium with the receiving volume. In this way, fluid flow in the chamber is prevented, i.e., the fluid is stationary in the chamber.

[0040] The applicant has verified that, since fluid is present in both the receiving volume and the chamber, the use of a double enclosure according to the third aspect allows for an inner housing with a reduced thickness to be achieved, thereby saving material because the inner housing does not have to withstand the fluid pressure.

[0041] Even when subjected to deformation imposed by the solid inert material, the thinner inner shell is capable of operating in an elastic deformation field. Additionally, the inner housing with a reduced thickness allows for limiting the flow of heat in the axial direction in the walls of the inner housing in contact with the fluid, so as to avoid transferring heat from a high-temperature region to a low-temperature region, thereby contributing to maintaining a narrow temperature change layer.

[0042] The tube and the inner housing with a reduced thickness also allow for reducing the weight of the reservoir and thus facilitate transportation and installation.

[0043] The applicant has verified that the chamber with the thermal insulation material allows for reducing heat loss to the external environment.

[0044] The applicant has also verified that the similarity of thermal inertia allows for reducing the amount of mechanical stress caused by thermal expansion between the inner housing and the solid inert material at different temperatures.

[0045] The applicant has also verified that, due to the chamber with the thermal insulation material, the outer housing sized to withstand the fluid pressure is not affected by the temperature of the fluid, and the material of the outer housing has a higher allowable stress limit; thus, the outer housing can also be implemented with a smaller thickness. In other words, since the allowable stress of many materials including steel is known to decrease as the temperature increases, the insulated chamber allows for using an outer housing with a lower design temperature, and thus it is possible to alternatively use less expensive materials and / or a smaller thickness to construct the outer housing.

[0046] The applicant emphasizes that the device according to the present invention can be provided with both an inner tube and a double enclosure, or can be provided with an inner tube but without a double enclosure, or vice versa, can be provided with a double enclosure but without an inner tube.

[0047] Other aspects of the present invention are described below.

[0048] In one aspect according to the second aspect and possibly one or more of the other aspects, in the step of thermal energy storage, the hot fluid enters the reservoir through the second conduit and the second opening, and the cooled fluid leaves the reservoir through the first opening and the first conduit.

[0049] In one aspect according to the second aspect and possibly one or more of the other aspects, in the step of releasing the thermal energy previously stored in the solid inert material, the cold fluid enters the reservoir through the first conduit and the first opening, and the heated fluid leaves the reservoir through the second opening and the second conduit.

[0050] In the storage step, the filling of the hot fluid into the reservoir and the leaving of the cooled fluid from the reservoir occur at the first end of the reservoir located at the bottom. The hot fluid flows through the entire tube before leaving through the second opening located near the second end of the reservoir positioned at the top. Then, the hot fluid leaving through the second opening passes through the solid inert material to release heat to the solid inert material and leaves through the first conduit located at the bottom. It should be noted that in this way, the hot part of the reservoir is always at the top, and this helps to retain heat. In fact, vice versa, if the filling were to be carried out from the bottom, in the case of partial filling, a convection phenomenon would be triggered, which would significantly extend the thermocline.

[0051] In the release step, the filling of the cold fluid into the reservoir and the leaving of the heated fluid from the reservoir always occur at the first end of the reservoir located at the bottom. The cold fluid enters through the first conduit located at the bottom and travels upward through the solid inert material to absorb heat. The heated fluid enters the second opening located near the second end of the reservoir positioned at the top and flows through the entire tube before leaving through the second conduit. Thus, during both storage and release, the hot fluid passes through the tube.

[0052] The applicant has verified that in this configuration, the hot fluid passes through the tube located inside the reservoir before leaving through the second opening, and thus heat losses to the environment can be avoided or limited, which could occur if the tube were outside the reservoir. In fact, if a part of the heat of the fluid flowing inside the tube were to pass through the wall of the tube itself, this heat would be stored in the solid inert material.

[0053] Furthermore, once the fluid flow has stopped, considering the reduced thermal inertia of the tube, the tube does not cool suddenly, such that during a subsequent storage step or a subsequent release step, the heat of the fluid inside the tube is not used to reheat the tube again, which would occur if the tube were outside the reservoir and would be cooled during this period.

[0054] In one aspect, the reservoir has an elongate cylindrical shape and has a main axis of extension.

[0055] In one aspect, the reservoir has a circular cross-section.

[0056] In one aspect, the tube and the reservoir are coaxial.

[0057] In one aspect, the ratio H / D between the length H of the reservoir (which corresponds to the height in the case of a vertical orientation) and the outer diameter D of the reservoir is between 2 and 15, optionally between 5 and 10.

[0058] The applicant has verified that these ratios allow optimizing heat exchange and controlling pressure losses.

[0059] In one aspect, in the vertical position of the reservoir, the main axis of extension and the main axis of the tube are vertical.

[0060] In one aspect, the heating curve T1 of the inner casing follows the heating curve T2 of the solid inert material and, in at least one intermediate section between a minimum temperature T min and a maximum temperature T max the heating curve T1 of the inner casing lies below the heating curve T2 of the solid inert material.

[0061] The applicant has verified that in this way the inner casing expands temporarily (shortly after) after the solid inert material has expanded and this prevents the solid inert material, in the case where it is a non-cohesive material, from causing the liquid level in the reservoir to drop due to an increase in the accommodation volume.

[0062] In one aspect, the inner casing expands freely thermally relative to the outer casing. In this way, neither the outer casing nor the inner casing is subjected to mechanical stress. Possibly, the expansion of the inner casing determines the compression of the insulating material, however, the insulating material does not offer resistance.

[0063] In one aspect, the inner casing is constrained to the outer casing by supports configured to avoid creating thermal bridges.

[0064] In one aspect, the supports are spaced apart by a rigid insulating material, such as a ceramic matrix material.

[0065] In this way, heat transfer from the inner casing to the outer casing is minimized.

[0066] In one aspect, the inner housing and the solid inert material have different coefficients of thermal expansion. In cases where the materials of the solid inert material and the inner housing are different and have different coefficients of thermal expansion, the inner housing may undergo deformation imposed by the solid inert material. As described above, due to the fact that the inner housing can operate in an elastic field, a thinner inner housing can also withstand such deformation.

[0067] In one aspect, the thickness of the inner housing wall is between 1 / 10 and 1 / 5 of the thickness of the outer housing wall.

[0068] In one aspect, the radial dimension of the chamber is between 5 times and 25 times the thickness of the outer housing wall.

[0069] In one aspect, the wall thickness of the tube is between 1 / 25 and 1 / 5 of the thickness of the outer housing wall.

[0070] In one aspect, the thickness of the inner housing wall is between 1 mm and 15 mm.

[0071] In one aspect, the wall thickness of the tube is between 0.2 mm and 15 mm.

[0072] In one aspect, the thickness of the outer housing wall is between 10 mm and 150 mm.

[0073] In one aspect, the channel of the inner housing is formed in the upper portion of the inner housing. The chamber is in fluid communication with the accommodation volume only through such a channel placed at the top.

[0074] In one aspect, the lower portion of the accommodation volume is sealed relative to the chamber. In this way, the fluid cannot bypass the heat mass, but can only pass through the chamber, and this prevents any hot fluid bypassing the heat mass from heating the outer housing.

[0075] In one aspect, the thermal insulation material located in the chamber includes multiple layers that are also different from each other. In fact, some materials provide optimal performance at high temperatures, some materials provide optimal performance at medium temperatures, and some materials provide optimal performance at low temperatures.

[0076] In one aspect, the tube is covered with a thermal insulation coating.

[0077] The inner tube is insulated relative to the heat mass in order to reduce the heat released to the heat mass, which is useful for maintaining a narrow temperature change layer.

[0078] In one aspect, the thermal insulation coating is placed on the radial inner side or the radial outer side of the tube.

[0079] In other words, the tube is encapsulated so that the heat of the fluid does not dissipate towards the solid inert material before the fluid reaches the second opening, while the solid inert material remains relatively cold and does not disrupt the temperature change layer.

[0080] In one aspect, the thermal insulation coating is free to slide axially relative to the tube due to thermal expansion.

[0081] In one aspect, the thermal insulation coating includes a radially inner sleeve and an insulating member located between the radially inner sleeve and the tube.

[0082] In one aspect, only the radially inner sleeve, or the radially inner sleeve and the insulating member, are free to slide axially relative to the tube due to thermal expansion.

[0083] In one aspect, the ratio between the heat exchange surface and the weight of the material of the tube is between 20 m 2 / ton and 300 m 2 / ton.

[0084] In one aspect, a first conduit passes through the outer housing and is connected to the inner housing.

[0085] In one aspect, a second conduit passes through the outer housing.

[0086] In one aspect, the first conduit and / or the second conduit includes a thermal insulation coating to prevent heat from reaching the outer housing and to limit heat loss.

[0087] In one aspect, the reservoir includes elements for supporting a non-cohesive material disposed in the accommodation volume, such as, for example, perforated shelves or meshes.

[0088] In one aspect, the elements for supporting the non-cohesive material include at least one shelf, optionally including a plurality of shelves.

[0089] In one aspect, the elements for supporting the non-cohesive material are placed within the non-cohesive material.

[0090] In one aspect, the elements for supporting the non-cohesive material have a thermal inertia similar to that of the non-cohesive material.

[0091] In one aspect, at least one filter is provided in or on the first opening and / or in or on the second opening.

[0092] In one aspect, the present invention also relates to a device for storing and releasing thermal energy, the device including at least one device as shown in one or more of the foregoing aspects.

[0093] In one aspect, the device further includes:

[0094] A first external pipeline and a second external pipeline associated with the at least one device, wherein the first external pipeline is connected to a first conduit of the reservoir, and the second external pipeline is connected to a second conduit of the reservoir, and wherein the first external pipeline and the second external pipeline are configured to be connected to a hot fluid source or a cold fluid source;

[0095] A valve that operates on the first external pipeline and the second external pipeline and / or on the first conduit and the second conduit, and is capable of being configured to allow a hot fluid or a cold fluid to enter through a first opening and leave through a second opening or enter through the second opening and leave through the first opening.

[0096] In one aspect, the device is configured to determine that fluid enters the reservoir through the second conduit and determine that fluid leaves the reservoir through the first conduit, or determine that fluid enters the reservoir through the first conduit and determine that fluid leaves the reservoir through the second conduit.

[0097] In one aspect, the device is configured to perform a step of thermal energy storage, in which the hot fluid from the second external pipeline enters the reservoir through the second conduit, flows in the pipe, leaves through the second opening, passes through the solid inert material to release heat to the solid inert material, leaves the reservoir through the first conduit, and flows in the first external pipeline.

[0098] In one aspect, the device is configured to perform a step of thermal energy release, in which the cold fluid from the first external pipeline enters the reservoir through the first conduit, passes through the solid inert material to absorb heat from the solid inert material, enters the second opening and flows in the pipe, leaves the reservoir through the second conduit, and flows in the second external pipeline.

[0099] In one aspect, the device includes a plurality of the devices that are in fluid communication with each other.

[0100] In one aspect, the devices in the plurality of devices are connected in series with each other, wherein the second conduit of a device is connected to the first conduit of an adjacent device, and the first conduit of a device is connected to the second conduit of an adjacent device.

[0101] In one aspect, the devices in the plurality of devices are connected in parallel with each other, wherein the first conduits of the devices are connected in parallel with each other, and the second conduits of the devices are connected in parallel with each other.

[0102] In one aspect, the plurality of devices includes groups of devices.

[0103] In one aspect, the devices in each group are connected in parallel with each other, and the groups are connected in series with each other.

[0104] In one aspect, the devices of each group are connected in series with each other, and the groups are connected in parallel with each other.

[0105] The characteristics of a single device are such that the energy that can be stored and the optimal volumetric flow rate are functions of the thermal power. To meet the project specifications, in the case where increased power is required, it is sufficient to arrange multiple devices in parallel, or in the case where increased energy is required, it is sufficient to arrange multiple devices in series. Additionally, arranging at least two devices in series allows bypassing the reservoir when the reservoir is full or when the reservoir is not in use (e.g., the fluid leaves the previous device in a cold state), and at the same time allows reducing the total pressure loss, thus allowing selection of a reservoir shape with a higher height / diameter ratio (H / D) at the same pressure loss, and therefore allowing improved performance.

[0106] In one aspect, each group includes the same number of devices or a different number of devices.

[0107] To further reduce the pressure loss, a central group with multiple devices connected in parallel with respect to the previous group and the next group can be used.

[0108] In one aspect, the devices among the multiple devices are identical to each other. In this way, the design cost and implementation cost can be reduced, and the number and arrangement of such devices can be selected to meet specific project requirements.

[0109] In one aspect, different devices or different groups contain different or the same solid inert materials.

[0110] In one aspect, the reservoir is made of steel, preferably carbon steel.

[0111] The applicant has confirmed that the equipment according to the present invention generally allows obtaining the following technical benefits, energy benefits, and mechanical benefits.

[0112] Energy benefits:

[0113] - High heat transfer coefficient of the heat mass and high thermal conductivity of the high heat mass, i.e., low Biot number;

[0114] - Reduction of the pressure loss of the fluid when passing through the heat mass;

[0115] - Reduction of the heat loss to the environment;

[0116] - Reduction of the thermal inertia and thus reduction of the irreversibility;

[0117] - High front of the variable temperature layer and no heat flow generated by conduction inside the reservoir, and thus reduction of the irreversibility;

[0118] Mechanical benefits and thus cost benefits:

[0119] - The stress of the reservoir is reduced due to the combination of medium pressure / high pressure;

[0120] - The allowable stress limit of the reservoir material is increased;

[0121] - It can withstand higher thermal gradients;

[0122] - The problem of heat mass accumulation caused by the temperature / thermal expansion difference of the reservoir is reduced.

[0123] The present invention also relates to an energy conversion and storage facility, which includes at least one device according to one or more of the foregoing aspects.

[0124] In one aspect, the facility further includes a hot fluid source and a cold fluid source, wherein the facility is configured to connect the at least one device to the hot fluid source or the cold fluid source such that the hot fluid or the cold fluid passes through the accommodation volume of one or more reservoirs and the solid inert material.

[0125] In one aspect, the facility is of the type described in one of the documents WO2021191786A1 and WO2021255578A1 on behalf of the same applicant, and the device of the present invention is used as a thermal energy storage (thermal energy storage - TES) in these facilities.

[0126] In one aspect, the facility includes:

[0127] A working fluid other than atmospheric air;

[0128] A gas meter or other storage system with low overpressure or no overpressure, which is configured to store the working fluid in the gaseous phase in each operating condition / step of the facility and is in pressure balance with the atmosphere;

[0129] A reservoir configured to store the working fluid in a liquid phase or a supercritical phase at a temperature close to the critical temperature, wherein the critical temperature is close to the ambient temperature, preferably between 0°C and 100°C;

[0130] Wherein, the facility is configured to actuated a closed-cycle thermodynamic conversion between the enclosure and the reservoir first in one direction in the storage configuration and then in the opposite direction in the discharge configuration; wherein, in the storage configuration, the facility stores heat and pressure, and in the discharge configuration, the facility generates energy;

[0131] Wherein, the device is configured to store heat in the storage configuration and release heat in the discharge configuration.

[0132] Examples of storage systems with low or no overpressure are double - membrane or triple - membrane gas meters, where there is a chamber between the inner membrane containing the working fluid and the outer membrane in contact with the environment. The chamber is usually filled with ambient air by means of a fan and maintained at a constant pressure of a few millibars, for example, from 1 [mbar] to 200 [mbar], preferably from 2 [mbar] to 50 [mbar]. The outer membrane always maintains its shape except for minor variations, in order to protect the inner membrane from the external environment and weather conditions such as sun, rain, wind, snow, etc.

[0133] Other examples of gas meters in equilibrium with the atmosphere are pressure balloons or single - membrane gas meters, where the membrane containing the working fluid is in direct contact with the atmosphere.

[0134] The membrane is usually made of a polyester fabric coated with PVC or by the coupling of multiple materials, one material giving the membrane strength and the other making it waterproof. Various additives can also be used to give it anti - aging properties while maintaining the high flexibility of the material.

[0135] In one aspect, the facility includes:

[0136] A working fluid other than atmospheric air;

[0137] An enclosure configured to store the working fluid in a gaseous phase and at a substantially constant pressure, where the working fluid in the enclosure is in pressure equilibrium with the atmosphere and has a small overpressure or no overpressure;

[0138] A reservoir configured to store the working fluid in a liquid phase or supercritical phase at a temperature close to the critical temperature, where the critical temperature is close to the ambient temperature;

[0139] At least one compressor;

[0140] At least one expander;

[0141] A heat exchanger configured to store the thermal energy released from the working fluid or to release previously stored thermal energy to the working fluid;

[0142] Wherein the enclosure is in fluid communication with the inlet of the compressor or with the outlet of the expander, and wherein the heat exchanger is in fluid communication with the outlet of the compressor or with the inlet of the expander;

[0143] Wherein the facility is configured to actuate a closed - cycle thermodynamic conversion between the enclosure and the reservoir first in one direction in a storage configuration and then in the opposite direction in a discharge configuration;

[0144] Wherein, in the storage configuration, the facility stores heat and pressure, and in the discharge configuration, the facility generates energy;

[0145] Among them, the heat exchanger includes:

[0146] A first heat exchanger, which is defined by the at least one device and is positioned between the reservoir and the compressor and between the reservoir and the expander;

[0147] A second heat exchanger, which operates operatively between the at least one device and the reservoir or operates operatively in the reservoir.

[0148] In one aspect, pipelines and control devices such as valves, pumps, etc. allow the facility to be configured into a storage configuration or a discharge configuration.

[0149] In one aspect, the at least one device is connected such that the working fluid of the facility passes through the accommodation volume of the reservoir of the at least one device; the at least one compressor defines a source of hot fluid in the storage configuration, and the second heat exchanger defines a source of cold fluid in the discharge configuration.

[0150] Alternatively, the at least one device is connected such that the working fluid of the facility exchanges heat with a fluid heat carrier, and wherein the fluid heat carrier passes through the accommodation volume of the reservoir of the at least one device.

[0151] In one aspect, the working fluid is in a gaseous phase.

[0152] In one aspect, the working fluid is selected from the group consisting of: CO 2 , SF 6 , N 2 O, or a mixture thereof.

[0153] In one aspect, the heat carrier is a liquid and is selected from the group consisting of: heat transfer oil, molten salt, and a general fluid used as a heat carrier.

[0154] The applicant has confirmed that the facility shown above stores heat in the storage configuration so as to be able to improve the overall efficiency of the system, and the very efficient device (TES) according to the present invention allows the efficiency and RTE (round-trip efficiency) of the facility in which such a device is inserted to be improved.

[0155] Through the detailed description of the preferred but non-exclusive embodiments of the device, equipment, and facility according to the present invention, other features and advantages will become more apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0156] The following description will be illustrated with reference to the drawings, the provided drawings are for illustrative purposes only and are thus not limited thereto, in the drawings:

[0157] ■ Figure 1Shows a device for storing and releasing thermal energy according to the present invention;

[0158] ■ Figure 2A and Figure 2B Schematically shows the Figure 1 device in a respective operating configuration;

[0159] ■ Figure 3A and Figure 3B Schematically shows a device for storing and releasing thermal energy, the device comprising a plurality of devices in respective operating configurations;

[0160] ■ Figure 4A and Figure 4B Schematically shows the Figure 3A and Figure 3B different embodiments of the device;

[0161] ■ Figure 5 、 Figure 6 and Figure 7 Show other embodiments of the device for storing and releasing thermal energy;

[0162] ■ Figure 8 Shows an energy conversion and storage facility according to the present invention. Detailed Description

[0163] Referring to the drawings, the device for storing and releasing thermal energy according to the present invention is generally indicated by the reference numeral 1. The device according to the present invention is of the packed bed type (a packed bed pressurized at atmospheric pressure or at low pressure) and includes a thermo-mass body configured to be surrounded by a fluid, the fluid releasing heat to or subtracting heat from the thermo-mass body.

[0164] The device 1 includes a reservoir 2. The reservoir 2 includes an outer housing 3 configured to support the pressure of the fluid and an inner housing 4 that defines an accommodation volume 5 within itself. The fluid can be in a gaseous or liquid phase.

[0165] In the illustrated embodiment, the reservoir 2 has an elongated cylindrical shape with a main extension axis Y-Y and a circular cross-section. The outer housing 3 and the inner housing 4 have the same or similar shapes and different dimensions from each other.

[0166] When correctly installed for operation, the reservoir 2 is vertically oriented, i.e., its main extension axis Y-Y is vertical, and the reservoir 2 is positioned on the ground or on a suitable support by means of feet 6 connected to the outer casing 3. Considering that H is the height of the reservoir 2 and D is its diameter, the H / D ratio is between 2 and 15, optionally between 5 and 10, to optimize heat exchange and suppress pressure losses. In the example embodiment shown, this H / D ratio is approximately equal to 5. A higher height / diameter (H / D) ratio allows for improved performance at the same pressure drop.

[0167] The inner casing 4 is constrained to the outer casing 3 by supports 7 configured to avoid creating thermal bridges and to avoid or minimize heat transfer from the inner casing 4 to the outer casing 3. Figure 1 Two supports 7 can be seen in

[0168] which are positioned near the first end of the reservoir 2 located at the bottom. The supports 7 are spaced apart by a rigid insulating material such as a ceramic matrix material. Figure 1 The inner casing 4 and the outer casing 3 are coaxial and positioned relative to each other such that there is a gap 8 defined between them, and the shape of the gap 8 is similar to the shape of one of the reservoirs in the reservoir 2. The chamber 8 is filled with a thermal insulation material 9 to reduce heat loss to the external environment. Since the chamber is filled with a thermal insulation material, the outer casing is hardly affected by the temperature of the fluid. The thermal insulation material 9 includes

[0169] multiple layers not visible in

[0170] which are concentric with each other and made of different materials, such as for example rock wool, glass wool, ceramic materials, rigid and flexible microporous materials, calcium silicate.

[0171] The first conduit 11 passes through the outer housing 3, through the chamber 8 and is connected to the inner housing 4 so as to put the accommodation volume 5 in fluid communication with the exterior of the reservoir 2, in particular in fluid communication with a first pipeline 12 outside the reservoir 2 and to prevent fluid from the first conduit 11 from flowing directly into the chamber 8. The first conduit 11 has a first opening 13 which opens into the accommodation volume 5 at a first end of the reservoir 2 located at the bottom and near the feet 6.

[0172] A second conduit 14 passes through the outer housing 3, through the chamber 8 and is connected to the inner housing 4 so as to likewise put the accommodation volume 5 in fluid communication with the exterior of the reservoir 2, in particular in fluid communication with a second pipeline 15 outside the reservoir 2 and to prevent fluid from the second conduit 14 from flowing directly into the chamber 8.

[0173] The second conduit 14 includes a tube 16 extending within the accommodation volume 5 or is connected to the tube 16.

[0174] In Figure 1 the illustrated embodiment, the tube 16 and the reservoir 2 are coaxial, i.e., the main extension axis Y-Y of the reservoir 2 coincides with the main axis of the tube 16. The tube 16 extends vertically up to a second end of the reservoir 2 located at the top and terminates in a second opening 17 which opens into the accommodation volume 5, i.e., into the inner housing 4. The second opening 17 is formed at the end end of the tube 16 which faces the upper part of the inner housing 4 formed with a passage and is spaced apart from the upper part of the inner housing so as to allow fluid to leave or enter the tube 16 through the second opening 17. Filters may be arranged in the first opening 13 and on the second opening 17. The filter 17a on the second opening 17 is visible in Figure 1 . The accommodation volume 5 is delimited by the radially inner surface of the inner housing 4 and the radially outer surface of the tube 16.

[0175] A support element 18 is positioned within the inner housing 4. The support element 18 is, for example, configured as a shelf provided with through openings. For example, the shelf is perforated or shaped as a mesh. A first shelf 18 is located near the lower part of the accommodation volume 5 and is placed exactly above the first opening 13. Other shelves 18 are spaced along the vertical extension of the reservoir 2. The shelves 18 are supported by the inner housing 4.

[0176] Furthermore, the outer housing 3 and the inner housing 4 are provided with doors which are configured to allow access to the accommodation volume 5 when the device 1 is not in operation, and to fill the device 1 with a non-adhesive material 19 or to discharge the non-adhesive material 19 for replacement and / or maintenance of the non-adhesive material 19. For this purpose, the shelves 18 are also removable.

[0177] The non - cohesive material 19 is a solid inert material that includes a plurality of bodies or elements not joined together, such as stones or gravel or metal spheres, for example iron or ceramic, and is configured to hold heat released from the fluid or release heat to the fluid during the conveyance of the fluid according to the process described below.

[0178] The Biot number of the non - cohesive material is less than 1, preferably less than 0.1.

[0179] The ratio between the heat - exchange surface of the tube 16 and the weight of the material of the tube 16 is preferably between 20 m 2 / ton and 300 m 2 / ton.

[0180] The elements of the non - cohesive material 19 are located on the shelves 18 and completely fill the transverse section of the receiving volume 5, while still allowing the fluid to pass through the receiving volume 5 from the first opening 13 to the second opening 17 or from the second opening 17 to the first opening 13 due to the gaps defined between the elements of the non - cohesive material 19. The non - cohesive material 19 defines the previously mentioned packed - bed heat mass.

[0181] The filter 17a located at the second opening 17 allows to avoid the fluid flow dragging the non - cohesive material into the tube during the discharge step described in detail below, and thus allows to fill the inner housing 4 up to the top of the receiving volume 5, so as to better utilize the receiving volume 5 and increase the ratio between the non - cohesive material and the inner housing 4.

[0182] In an embodiment variant not shown in the figures, the solid inert material is a cohesive material in which channels and / or chambers are defined, such as a single material block with chambers, in order to achieve good heat - exchange characteristics.

[0183] The tube 16 includes a thermal insulation coating 20, i.e., the tube is encapsulated. In Figure 1 the embodiment, the thermal insulation coating 20 is placed on the radial inner side of the wall of the tube 16. The thermal insulation coating 20 includes a radial inner housing and an insulator that is in close contact with the radial inner housing and is placed between the housing and the tube 16. The thermal insulation coating 20 is configured such that it can axially slide relative to the tube 16 in the presence of thermal expansion. In a variant, the insulator of the thermal insulation coating 20 is in close contact with the tube 16, and the radial inner housing is axially free to slide relative to the insulator and the tube 16.

[0184] In addition, the first conduit 11 and / or the second conduit 14 include corresponding thermal insulation covers to prevent heat from reaching the outer housing and limit heat losses.

[0185] The inner housing 4, the outer housing 3, and the tube 16 are made of carbon steel.

[0186] The outer housing 3 is dimensioned such that it supports the pressure of the fluid that fills both the inner housing 4 and the chamber 8. On the other hand, the inner housing 4 does not have to support the fluid pressure since the fluid is present in both the receiving volume 5 and the chamber 8. Thus, the inner housing 4 can be realized with a reduced thickness relative to the thickness of the outer housing 3.

[0187] For example, the thickness of the wall of the inner housing 4 is between 1 / 10 and 1 / 5 of the thickness of the wall of the outer housing 3. The wall of the tube 16 is also thinner, for example, the thickness of this wall is between 1 / 25 and 1 / 5 of the thickness of the wall of the outer housing 3. For example, the thickness of the wall of the inner housing 4 is between 1 mm and 15 mm, the thickness of the wall of the tube 16 is between 0.2 mm and 15 mm, and the thickness of the wall of the outer housing 3 is between 10 mm and 150 mm. The radial dimension of the chamber 8 is between 5 times and 25 times the thickness of the wall of the outer housing 4.

[0188] The limited thickness of the inner housing 4 allows the inner housing 4 to operate within the elastic deformation range even when subjected to deformation exerted by the non - adhesive material 19 - since the non - adhesive material 19 also expands. In addition, the reduced thickness of the inner housing 4 allows limiting the heat flow in the walls of the inner housing 4 that are in contact with the fluid.

[0189] The inner housing 4 is realized such that it has a thermal inertia similar to that of the non - adhesive material 19, so that the inner housing 4 and the non - adhesive material 19 are heated together. The similarity of the thermal inertia allows avoiding mechanical stress. In addition, the inner housing 4 is realized such that the heating curve T1 of the inner housing 4 follows the heating curve T2 of the non - adhesive material 19, and in at least one intermediate section between the minimum temperature T min and the maximum temperature T max the heating curve T1 of the inner housing 4 is located below the heating curve T2 of the non - adhesive material 19, as Figure 1A shown. Figure 1A The heating curves T1 and T2 are shown in a "time (t) - temperature (T)" diagram. In addition, the temperature is approximately proportional to the thermal expansion of the inner housing 4 and the non - adhesive material 19. At the time "ti", the temperature of the non - adhesive material 19 is higher than the temperature of the inner housing 4 by ΔT, whereby the inner housing 4 expands temporarily (shortly after) after the non - adhesive material 19 has expanded, and this prevents the non - adhesive material 19 from lowering its liquid level in the receiving volume 5 of the reservoir 2 due to the increase (also due to the temperature increase) of the receiving volume 5.

[0190] In addition, the inner housing 4 and the non-bonding material 19 may have different coefficients of thermal expansion from each other. If the coefficient of thermal expansion of the non-bonding material is greater than that of the inner housing 4, when the non-bonding material 19 and the inner housing 4 are heated, the inner housing 4 may undergo deformation imposed by the non-bonding material 19, and the inner housing 4 can withstand this deformation due to the fact that it is thinner and can operate within the elastic range.

[0191] The various components of the device 1 are designed such that they operate within the elastic range of the materials of the device 1, such that there is no permanent deformation "hysteresis" during various cycles.

[0192] The device 1 itself having the first pipeline 12 and the second pipeline 15 can define a device 100 for storing and releasing thermal energy.

[0193] The first external pipeline 12 and the second external pipeline 15 are configured to be connected to a hot fluid source 101 or a cold fluid source 102, as Figure 2A and 2B schematically shown in. Valves (not shown and known per se) operate, for example, on the first external pipeline 12 and / or the second external pipeline 15 and / or the first conduit 11 and / or the second conduit 14, and can be configured to allow hot fluid to enter through the first opening 13 and leave through the second opening 17, or enter through the second opening 17 and leave through the first opening 13.

[0194] The device 100 is configured to perform the step of storing the thermal energy contained in the hot fluid from the hot fluid source 101, or to perform the step of releasing the thermal energy previously stored in the non-bonding material 19 in the reservoir 2 to the cold fluid from the cold fluid source 102.

[0195] In Figure 2A the step of storing thermal energy in the non-bonding material 19 as shown, the hot fluid from the hot fluid source 101 flows through the second external pipeline 15, enters the reservoir 2 through the second conduit 14, flows in the pipe 16 and leaves through the second opening 17, passes downward through the non-bonding material 19 to release heat to the non-bonding material 19, leaves the reservoir 2 through the first opening 13 and the first conduit 11, and flows in the first external pipeline 12 until the cold fluid reservoir 102'.

[0196] In Figure 2B the step of releasing thermal energy from the non-bonding material 19 as shown, the cold fluid from the cold fluid source 102 flows through the first external pipeline 12, enters the reservoir 2 through the first conduit 11, passes upward through the non-bonding material 19 to absorb heat from the non-bonding material 19, enters the second opening 17 and flows in the pipe 16, leaves the reservoir 2 through the second conduit 14, and flows in the second external pipeline 15 until the hot fluid reservoir 101'.

[0197] As can be observed, in both the storage step and the release step, the hot fluid passes through the tube 16. Thus, the positioning of the tube 16 within the accommodation volume 5 allows avoiding or at least suppressing heat loss to the environment outside the reservoir 2, which could occur if the tube were positioned outside the reservoir. Moreover, once the flow of the fluid through the tube 16 stops, the tube 16 does not cool down suddenly, such that during a subsequent storage step or a subsequent release step, the heat of the fluid passing through the tube 16 is not used to reheat the tube 16 again, which would occur if the tube 16 were outside the reservoir and would be cooled during this period.

[0198] Moreover, during the step of storing thermal energy in the non - cohesive material 19, the hot fluid is filled into the accommodation volume 5 from the top (assuming the second opening 17 is at the top) and exits from the bottom through the first opening 13. This configuration helps the non - cohesive material to work properly and optimizes its heat storage capacity, since heat always tends to travel upwards.

[0199] In a variant of the embodiment, the device 100 mentioned includes a plurality of devices 1 that are in fluid communication with each other. The devices 1 can be the same or different from each other, and the non - cohesive materials 19 accommodated in the respective reservoirs 2 can also be the same or different.

[0200] Figure 3A and Figure 3B The device 100 is shown, which includes three devices 1 that are identical to each other and are connected in series with each other.

[0201] The first conduit 11 and the first pipeline 12 of the left - hand device 1 are connected to the second pipeline 15 and the second conduit 14 of the central device 1. The first conduit 11 and the first pipeline 12 of the central device 1 are connected to the second pipeline 15 and the second conduit 14 of the right - hand device 1. The second pipeline 15 and the second conduit 14 of the left - hand device 1 are connected to a hot - fluid source 101 (not shown). The first conduit 11 and the first pipeline 12 of the left - hand device 1 are connected to a cold - fluid source 102 (not shown).

[0202] A bypass conduit 120 with a corresponding bypass valve 130 allows bypassing the reservoir when it is full or when it is not in use.

[0203] In Figure 3A the step of storing thermal energy in the non - cohesive material 19 as shown, the hot fluid from the hot - fluid source 101 successively and continuously passes through the three devices 1 and releases heat to the non - cohesive material 19 in each of the reservoirs 2.

[0204] In Figure 3BIn the step of releasing thermal energy from the non - adhesive material 19 shown, the cold fluid from the cold fluid source 102 sequentially and continuously passes through the three devices 1 and absorbs heat from the non - adhesive material 19 in each reservoir of the reservoir 2.

[0205] Figure 4A and Figure 4B The device 100 is shown, which includes three identical devices 1 connected in parallel.

[0206] The first conduits 11 and the first pipelines 12 of the three devices 1 are connected in parallel, that is, all are directly connected to the cold fluid source 102.

[0207] The second conduits 14 and the second pipelines 15 of the three devices 1 are connected in parallel, that is, all are directly connected to the hot fluid source 101.

[0208] In Figure 4A In the step of storing thermal energy in the non - adhesive material 19 shown, the hot fluid from the hot fluid source 101 simultaneously passes through the three devices 1 and releases heat to the non - adhesive material 19 in each reservoir of the reservoir 2.

[0209] In Figure 4B In the step of releasing thermal energy from the non - adhesive material 19 shown, the cold fluid from the cold fluid source 102 simultaneously passes through the three devices 1 and absorbs heat from the non - adhesive material 19 in each reservoir of the reservoir 2.

[0210] Connecting several devices 1 in parallel allows for increased power, and connecting several devices 1 in series allows for increased energy. Using the same device 1 allows for reduced design costs and implementation costs.

[0211] Figure 5 The device 100 is shown, where the devices 1 are in series and parallel. In particular, Figure 5 the device 100 includes five groups 110 of devices 1. Each group 110 includes four devices 1 connected in parallel with each other (as in the devices shown in Figure 4A and Figure 4B ). The groups 110 are connected in series with each other. In addition, each group 110 includes a bypass conduit 120, and the bypass conduit 120 is provided with corresponding bypass valves 130, and these bypass valves 130 allow bypassing one or more groups 110 when needed.

[0212] In a variant of the embodiment not shown, the devices 1 in each group 110 are connected in series with each other, and the groups 110 are connected in parallel with each other.

[0213] Figure 6 Shown is in connection with Figure 5A device similar to device 100, in which the individual devices 1 of different groups 110 are connected in series. This arrangement allows the fluid to mix as it leaves one group, so that it redistributes the mixture in the next group.

[0214] Figure 7 shows a device 100 similar to Figure 5 the device, in which the groups 110 are three groups connected in series. Each of the first group 110 and the last group 110 includes three devices 1, and the central group 110 includes six devices 1. With respect to the previous group 110 and the subsequent group 110, using a central group 110 having a number of devices connected in parallel with each other allows for a reduction in pressure loss.

[0215] For example, the temperature of the hot fluid entering one or more first reservoirs 2 is between 300 °C and 500 °C, for example about 400 °C, and the temperature of the hot fluid leaving one or more last reservoirs 2 is between 5 °C and 150 °C.

[0216] Figure 8 shows a facility 200 for processing and storing energy, the facility 200 including the device 100 as described above. The facility 200 may be an embodiment in the embodiments described in the published documents WO2021191786A1 and WO2021255578A1 on behalf of the same applicant. The device 100 according to the present invention is used as a thermal energy storage (thermal energy storage - TES) in the facility 200.

[0217] The illustrated facility 200 operates using a working fluid other than atmospheric air, the working fluid being selected, for example, from the group consisting of: carbon dioxide CO 2 , sulfur hexafluoride SF 6 , nitrous oxide N 2 O. The facility 200 is configured to actuate a closed - cycle thermodynamic conversion (TTC) first in a storage configuration / step in one direction and then in a discharge configuration / step in the opposite direction, wherein, in the storage configuration, the facility 200 stores heat and pressure, and in the discharge configuration, the facility 200 generates electrical energy.

[0218] Referring to Figure 8 , the facility 200 includes an expander such as a turbine 202 and a compressor 203 mechanically connected to the motor - generator shaft 204.

[0219] The facility 200 includes an enclosure 205 defined by a double-membrane gas meter, which includes an inner membrane 301 containing a working fluid and an outer membrane 302 in contact with the environment. The gas meter is disposed on a surface and is in external contact with atmospheric air. The inner membrane 301 of the gas meter defines a volume within itself, which is configured to contain a working fluid at atmospheric pressure or substantially atmospheric pressure, i.e., in pressure equilibrium with the atmosphere. The outer membrane 302 maintains its shape at all times except for minor variations, in order to protect the inner membrane from the external environment and weather conditions such as sun, rain, wind, snow, etc. The chamber defined between the inner membrane 301 and the outer membrane 302 is filled with ambient air by means of a fan and maintained at a constant pressure of a few millibars. The enclosure 205 can also be implemented at a lower overpressure or no overpressure like any other gas storage system, where the pressure remains constant or substantially constant as the volume of the working fluid changes.

[0220] A first pipe 206 is formed between the enclosure 205 and the inlet 203a of the compressor 203 and between the enclosure 205 and the outlet 202b of the turbine 202 to fluidly connect the inner volume of the enclosure 205 with the compressor 203 and the turbine 202. A valve or valve system (not shown) can be operatively disposed on the first pipe 206 to alternately fluidly connect the enclosure 205 with the inlet 203a of the compressor 203 or the outlet 202b of the turbine 202 with the enclosure 205.

[0221] The facility 200 includes a primary heat exchanger 100, which can be selectively in fluid communication with the outlet 203b of the compressor 203 or with the inlet 202a of the turbine 202. For this purpose, a second pipe 208 is formed between the inlet 202a of the turbine 202 and the primary heat exchanger 100 and between the outlet 203b of the compressor 203 and the primary heat exchanger 100.

[0222] The primary heat exchanger 100 is defined by the devices for storing and releasing thermal energy described previously and for the purposes of the present invention.

[0223] A valve or valve system (not shown) is operatively disposed on the second pipe 208 to alternately fluidly connect the primary heat exchanger 100 with the inlet 202a of the turbine 202 or the outlet 203b of the compressor 203 with the primary heat exchanger 100.

[0224] A reservoir 209 is in fluid communication with the primary heat exchanger 100, and the reservoir 209 is configured to store a working fluid in a liquid phase or a supercritical phase at a temperature close to the critical temperature. The critical temperature of the working fluid is close to the ambient temperature and preferably between 0°C and 100°C.

[0225] In the step of being stored in the reservoir 209, the secondary heat exchanger 210 operates upstream of the reservoir 209 and is configured to operate on the working fluid.

[0226] A third pipe 212 is formed between the primary heat exchanger 100 and the reservoir 209 to fluidly connect the primary heat exchanger 100 with the reservoir 209 and the secondary heat exchanger 210.

[0227] In Figure 8 In the schematic diagram of, the facility 200 further includes an additional heat exchanger 213 operatively disposed between the enclosure 205 and the compressor 202 and between the enclosure 205 and the turbine 202.

[0228] A pool 2000 having a liquid - typically water - is connected to the heat exchanger and the additional heat exchanger 213 and is coupled to a radiator 223 provided with an impeller 224.

[0229] The heat exchanger is configured to store the thermal energy released from the working fluid in the heat storage medium and the liquid of the pool, or release the previously stored thermal energy to the working fluid.

[0230] As described in the published documents WO2021191786A1 and WO2021255578A1, the facility is configured to actuate a closed - cycle thermodynamic conversion between the enclosure 205 and the reservoir 209 first in a storage configuration in one direction and then in a discharge configuration in the opposite direction.

[0231] In the storage configuration, the facility 200 stores energy in the form of heat and pressure. In the discharge configuration, the facility 200 generates mechanical energy and may convert it into electrical energy.

[0232] In the storage configuration, the working fluid from the enclosure 205 is compressed and heated in the compressor 203. Then, the working fluid flows through the primary heat exchanger 100 acting as a cooler to remove heat from the compressed working fluid, cool the working fluid, and store the thermal energy removed from the working fluid as heat in the non - cohesive material of the reservoir 2. The working fluid releases heat to the liquid of the pool 2000 at the secondary heat exchanger 210, condenses, and is stored in the reservoir 209.

[0233] In the discharge configuration, the working fluid from the reservoir 209 that has been heated by the secondary heat exchanger 210 passes through the primary heat exchanger 100, which now acts as a heater and releases the additional heat previously stored in the non - cohesive material 19 to the working fluid and heats the working fluid, and then feeds it into the turbine 202.

[0234] In the embodiment of the facility 200 shown above, the working fluid of the facility 200 passes through the accommodation volume 5 of the reservoir 2 of the device 100 in a gaseous phase and directly exchanges heat with the non - adhesive material 19 inside the accommodation volume. Thus, the compressor 203 defines, in the storage configuration, the overall heat - fluid source 101 shown generally in Figure 2A and the second heat exchanger 210 defines, in the discharge configuration, the overall cold - fluid source 102 shown generally in Figure 2B .

[0235] In an alternative embodiment (not shown), the device 100 is connected to the remainder of the facility 200 such that the working fluid of the facility 200 exchanges heat with a fluid heat - carrier, such as heat - conducting oil, and the fluid heat - carrier passes through the accommodation volume 5 of the reservoir 2 of the device 100 and then directly exchanges heat with the non - adhesive material 19 of the reservoir 2.

[0236] List of Reference Numerals

[0237] 1 Device for storing and releasing thermal energy

[0238] 2 Reservoir

[0239] 3 Outer housing

[0240] 4 Inner housing

[0241] 5 Accommodation volume

[0242] 6 Leg

[0243] 7 Support

[0244] 8 Chamber

[0245] 9 Thermal insulation material

[0246] 10 Channel

[0247] 11 First conduit

[0248] 12 First pipeline

[0249] 13 First opening

[0250] 14 Second conduit

[0251] 15 Second pipeline

[0252] 16 Pipe

[0253] 17 Second opening

[0254] 18 Shelf

[0255] 19 Solid inert material

[0256] 20 Thermal insulation coating

[0257] 100 Device for storing and releasing thermal energy.

[0258] 101 Heat fluid source

[0259] 101’ Reservoir of heat fluid

[0260] 102 Cold fluid source

[0261] 102’ Reservoir of cold fluid

[0262] 110 Group

[0263] 120 Bypass conduit

[0264] 130 Bypass valve

[0265] 200 Facility

[0266] 202 Turbine

[0267] 202a Inlet of the turbine

[0268] 202b Outlet of the turbine

[0269] 203 Compressor

[0270] 203a Inlet of the compressor

[0271] 203b Outlet of the compressor

[0272] 204 Motor - generator

[0273] 205 Enclosure

[0274] 206 First pipeline

[0275] 208 Second pipeline

[0276] 209 Reservoir

[0277] 210 Secondary heat exchanger

[0278] 212 Third pipeline

[0279] 213 Additional heat exchanger

[0280] 213a Cooler

[0281] 223 Radiator

[0282] 224 Impeller

[0283] 301 Inner membrane

[0284] 302 Outer membrane

[0285] 2000 Pond

[0286] The main axis of the X-X tube

[0287] The main extension axis of Y-Y.

Claims

1. A device for storing and releasing thermal energy, the device comprising: a reservoir (2) which internally defines a receiving volume portion (5); a first conduit (11) configured to fluidly connect the receiving volume portion (5) to a first pipeline (12) outside the reservoir (2), wherein the first conduit (11) has a first opening (13) that leads to the receiving volume portion (5) at a first end of the reservoir (2); a second conduit (14) configured to fluidly connect the receiving volume portion (5) to a second pipeline (15) outside the reservoir (2); wherein the second conduit (14) has a second opening (17) that leads to the receiving volume portion (5) at a second end of the reservoir (2) opposite the first end; a solid inert material (19) disposed in the receiving volume portion (5) and configured to allow fluid to flow through the receiving volume portion (5) from the second opening (17) to the first opening (13) or from the first opening (13) to the second opening (17); wherein the fixed inert material (19) is configured to hold heat released from the fluid or release heat to the fluid during the conveyance of the fluid; wherein the reservoir (2) is configured to operate in a vertical position such that the first end of the reservoir (2) is disposed at the bottom and the second end of the reservoir (2) is disposed at the top; wherein the first conduit (11) and the second conduit (14) open outwards at the first end of the reservoir (2), and the first external pipeline (12) and the second external pipeline (12) are located near the first end; wherein the second conduit (14) includes a tube (16) at least partially located within the receiving volume portion (5), and the second opening (17) is formed at the end of the tube (16) near the second end of the reservoir (2) such that the receiving volume portion (5) is delimited by the radially inner surface of the reservoir (2) and the radially outer surface of the tube (16); wherein the reservoir (2) includes an outer housing (3) configured to withstand fluid pressure, an inner housing (4) that supports the radially inner surface and defines the receiving volume portion (5), and a thermal insulation material (9) placed in a chamber (8) defined between the outer housing (3) and the inner housing (4); wherein the inner housing (4) has a passage (10) to allow the fluid to also fill the chamber (8) and bring the chamber (8) into pressure equilibrium with the receiving volume portion (5).

2. The device according to claim 1, wherein, the inner housing (4) has a thermal inertia similar to that of the solid inert material (19).

3. The device according to claim 1 or 2, wherein, In the time (t)-temperature (T) diagram, the heating curve (T1) of the inner housing (4) follows the heating curve (T2) of the solid inert material (19); and wherein, in at least one intermediate section between the minimum temperature (T min ) and the maximum temperature (T max ), the heating curve (T1) of the inner housing (4) lies below the heating curve (T2) of the solid inert material (19).

4. The device according to claim 1, 2 or 3, wherein, the inner housing (4) is freely thermally expandable relative to the outer housing (3).

5. The device according to any one of claims 1 to 4, wherein, the inner housing (4) is constrained to the outer housing (3) by a support member (7) configured to avoid creating a thermal bridge.

6. The device according to any one of claims 1 to 5, wherein, the inner housing (4) and the solid inert material (19) have different coefficients of thermal expansion.

7. The device according to any one of claims 1 to 6, wherein, the thickness of the wall of the inner housing (4) is between 1 / 10 and 1 / 5 of the thickness of the wall of the outer housing (3); wherein, the radial dimension of the chamber (8) is between 5 times and 25 times the thickness of the wall of the outer housing (3); wherein, the thickness of the wall of the tube (16) is between 1 / 25 and 1 / 5 of the thickness of the wall of the outer housing (3).

8. The device according to any one of claims 1 to 7, comprising a thermal insulation coating (20) covering the tube (16); wherein, the thermal insulation coating (20) is disposed on the radially inner side or the radially outer side of the tube (16).

9. The device according to claim 8, wherein, the thermal insulation coating (20) is axially freely slidable relative to the tube (16) due to thermal expansion.

10. The device according to any one of claims 1 to 9, wherein, the reservoir (2) has an elongated cylindrical shape with a main extension axis (Y - Y), wherein, in the vertical position of the reservoir (2), the main extension axis (Y - Y) and the main axis (X - X) of the tube (16) are vertical.

11. A device for storing and releasing thermal energy, the device comprising: at least one device (1) according to one or more of claims 1 to 10, a first external pipeline (12) and a second external pipeline (12) associated with the at least one device (1), wherein, the first external pipeline (12) is connected to the first conduit (11), and the second external pipeline (12) is connected to the second conduit (14), wherein, the first external pipeline (12) and the second external pipeline (12) are configured to be connected to a hot fluid source (101) or a cold fluid source (102); a valve, the valve operating on the first external pipeline (12) and the second external pipeline (12) and / or the first conduit (11) and the second conduit (14), and the valve being configurable to allow hot fluid or cold fluid to enter through the second opening (17) and leave through the first opening (13) or enter through the first opening (13) and leave through the second opening (17).

12. The device according to claim 11, comprising a plurality of the devices (1) in fluid communication with each other, wherein, the devices (1) among the plurality of devices (1) are connected in series and / or in parallel with each other.

13. The device according to claim 12, wherein, The plurality of devices (1) includes a group (110) of devices (1), wherein the devices (1) of each group (110) are connected in parallel with each other, and the groups (110) are connected in series with each other.

14. An energy conversion and storage facility, the energy conversion and storage facility comprising: a hot fluid source (101); a cold fluid source (102); at least one device (100) according to at least one of claims 11 to 13; wherein the facility (200) is configured to connect the at least one device (100) to the hot fluid source (101) or the cold fluid source (102) such that the hot fluid or the cold fluid passes through the accommodation volume (5) of one or more of the reservoirs (2) and the solid inert material (19).

15. The facility according to claim 14, comprising: a working fluid other than atmospheric air; an enclosure (205) configured to store the working fluid in a gaseous phase and at a substantially constant pressure, wherein the working fluid in the enclosure (205) is in pressure equilibrium with the atmosphere and has a small overpressure or no overpressure; a reservoir (209) configured to store the working fluid in a liquid phase or a supercritical phase at a temperature close to the critical temperature, wherein the critical temperature is close to the ambient temperature; at least one compressor (203); at least one expander (202); a heat exchanger (210, 100) configured to store thermal energy released from the working fluid or release previously stored thermal energy to the working fluid; wherein the enclosure (205) is in fluid communication with the inlet (203a) of the compressor (203) or with the outlet (202b) of the expander (202), and wherein the heat exchanger (210, 100) is in fluid communication with the outlet (203b) of the compressor (203) or with the inlet (202a) of the expander (202); wherein the facility (200) is configured to actuate a closed-cycle thermodynamic conversion (TTC) between the enclosure (205) and the reservoir (209) first in one direction in a storage configuration and then in the opposite direction in a discharge configuration; wherein in the storage configuration, the facility (200) stores heat and pressure, and in the discharge configuration, the facility (200) generates energy; wherein the heat exchanger (201, 100) comprises: a first heat exchanger defined by the at least one device (100) and located between the reservoir (209) and the compressor (203) and between the reservoir (209) and the expander (202); a second heat exchanger (210) operatively acting between the at least one device (100) and the reservoir (209) or operatively acting in the reservoir (209); Wherein, the at least one device (100) is connected such that the working fluid of the installation (200) passes through the receiving volume (5) of the reservoir (2) of the at least one device (100); the at least one compressor (202) defines the hot fluid source in the storage configuration, and the second heat exchanger (210) defines the cold fluid source in the discharge configuration; Or wherein, the at least one device (100) is connected such that the working fluid of the installation (200) exchanges heat with a fluid heat carrier, and wherein the fluid heat carrier passes through the receiving volume (5) of the reservoir (2) of the at least one device (100).

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