Method for building a storage, storage for a liquid, and use thereof

Abstract

The present invention relates to a storage system (1) for a heated liquid, comprising a plurality of container modules (2) and wherein: - each container module (2) delimits a storage compartment (4) for a heated liquid; - each container module (2) has a predefined length (L), predefined height (H) and predefined width (W); - said plurality of container modules (2) is arranged in an adjacent or mutually contacting position; - the predefined length (L) of each container module (2) is oriented substantially vertically; - the storage compartments (4) of the container modules are connected together with a fluid connection; - optionally said storage system (1) comprises a filling line (24) for filling said storage system by means of a liquid source (10) and, preferably, a supply line (26) connecting said storage system to a liquid user (12); wherein at least one container module (2) or a plurality of said container modules (2) comprises (a) at least one distributor or a header (32) located in a vertically lower portion (18) of the storage compartment (4) so as to supply the liquid to the container module (2) or convey the liquid outside of the storage compartment; and (b) at least one header or a distributor (34) located in a vertically upper portion (16) of the storage compartment (4) so as to convey the liquid outside of the storage compartment (4) or supply the liquid to the container module. The present invention also relates to a district heating plant, a building method and use of said storage system (1) as a thermal storage system

Description

Field of the invention

[0001] The invention relates to the sector of methods for building storage systems for liquids, preferably for use in district heating plants.Prior art

[0002] The use of thermal storage systems has been known for some time.

[0003] These storage systems are commonly used to store heated liquids when the demand for heat is low and to release these liquids when the demand for heat increases.

[0004] Thermal storage systems usually have a significant vertical height (for example 20 metres or more) and this results in a series of problems including risks: of a structural nature, with the need to provide suitable piling and foundations (in order to prevent critical situations due to earthquakes, wind and / or high weight); of a regulatory nature, in view of the fact that a storage system is a static structure which requires special permission for construction thereof; of a constructional nature, since as well as occupying a large area (roughly 200 m 3< ) it is also required to build a storage reservoir on-site with construction work lasting at least about 6-7 months; of a landscaping nature, with the need to erect concealment structures; and of a logistical nature, because of the need to transport equipment using exceptional transport.

[0005] Prior art documents include WO 2010 / 060147 A1 and AU 2019 229 103 A1.

[0006] The Applicant, after a long and in-depth R&D investigation work, has developed a storage system, a district heating plant and a method which are able to provide a suitable response to the existing limitations, drawbacks and problems. In particular, the Applicant has developed a building method, a storage system and a district heating plant which use a modular system of containers which may be generally arranged on existing foundations, which has a limited impact on the landscape and which, also from a logistical point of view, may be implemented without the use of exceptional transport.Summary of the invention

[0007] The object of the invention is to overcome the aforementioned drawbacks of the prior art.

[0008] Therefore, the present invention relates to a storage system which comprises a plurality of container modules and wherein: each container module delimits a storage compartment for a liquid; each container module has a predefined length, predefined height and predefined width; said plurality of container modules is arranged in an adjacent or mutually contacting position; the predefined length of each container module is oriented substantially vertically; the storage compartments of the container modules are connected together with a fluid connection; optionally said storage system comprises a filling line for filling said storage system by means of a liquid source and, preferably, a supply line connecting said storage system to a liquid user; wherein the container module comprises: (a) at least one distributor or header located in a vertically lower portion of the storage compartment for supplying the liquid to the container module or for conveying the liquid outside of the storage compartment; and (b) at least one header or distributor located in a vertically upper portion of the storage compartment for conveying the liquid outside of the storage compartment or for supplying the liquid to the container module.

[0009] It is pointed out that the expression "distributor" in case (a) and "header" in case (b) are to be understood as being such in an operating condition where the container module is supplied with the liquid from the distributor and that the liquid is drawn from the storage compartment via the header. This operating condition occurs, for example, during charging of the storage system by means of the liquid source.

[0010] Nevertheless, in a different operating condition ("discharging" of the storage system), the filling line 24 and the supply line 26 could be configured, respectively, to convey the liquid from the storage system 1 to the liquid source 10 and to convey the liquid form the liquid user 12 to the storage system 1.

[0011] In a different operating condition, the element called "distributor" with reference to charging of the storage system acts as a header during discharging of the storage system, while the element called "header" during charging of the storage system acts as a distributor during discharging of the storage system. This is due to the fact that the first one of these elements is located in a vertically lower portion of the storage compartment and the second one of these elements is located in a vertically upper portion of the storage compartment. From the structural point of view of the single container module 2 and the positioning of these elements inside the storage compartment there are no differences with respect to charging of the storage system, since when changing from charging to discharging only the direction of displacement of the liquid inside the storage system 1 is reversed.

[0012] Expressed in other words, the "header" in case (a) and the "distributor" in case (b) are to be understood as such during discharging of the storage system, and therefore in the operating condition in which the container module is supplied with the liquid from the distributor and the liquid is drawn from the storage compartment via the header.

[0013] The present invention also relates to a district heating plant comprising: said storage system; a heat generating station having the function of said liquid source for the heated liquid; wherein the storage system and the heat generating station are connected via the filling line and wherein the storage system is connected to one or more liquid users by means of at least one supply line; and at least one return line which connects said one or more liquid users to the heat generating station so as to form a circuit.

[0014] The present invention also relates to a method for building said storage system for a liquid. Said method comprises the following steps: (I) transporting a plurality of container modules; wherein each container module delimits a storage compartment for a liquid; wherein each container module has a predefined length, predefined height and predefined width; wherein, during step (I), the predefined length is oriented substantially horizontally; (II) arranging said plurality of container modules in an adjacent or mutually contacting position, wherein at least some of said container modules (for example, each container module) is rotated with respect to step (I) so that said predefined length is oriented substantially vertically; (III) realizing a fluid connection between the storage compartments of the container modules of step (II) so as to provide said storage system; IV) optionally filling the storage system of step (III) by means of a liquid source and, preferably, supplying a liquid user by means of the filled storage system.

[0015] The present invention also relates to use of said storage system as a thermal storage system.Advantages of the invention

[0016] The invention has the advantages which are described below.

[0017] Advantageously, the method and the storage system according to the present invention use standard size container modules which do not require special measures nor authorizations for transport thereof.

[0018] Advantageously, the method and the storage system according to the present invention have been designed such that a maximum overall height is not exceeded. As a result, said storage system is subject to a limited seismic risk, does not need to be covered with particularly extensive landscape concealment structures and, also as regards the installation costs, does not require the construction of special foundations or support piling. For example, the present storage system may be positioned on pre-existing platforms.

[0019] Advantageously, the method and the storage system according to the present invention allows construction on-site in a particularly short amount of time, of about one day, compared to the months which are required for the construction of a storage system according to the prior art.

[0020] Advantageously, the method and the storage system according to the present invention reduce and eliminate problems associated with execution of the work carried out at significant heights.

[0021] Advantageously, the method and the storage system according to the present invention do not require installation worksites or work which are particularly disruptive.

[0022] Advantageously, the method and storage system according to the present invention also solve the problem of thermal stratification (thermoclines) which conventionally occurs in the case of large-volume reservoirs. The present storage system guarantees, in fact, a uniform and improved distribution of the heat.

[0023] Advantageously, the method and the storage system according to the present invention use containers which constitute modular elements which can be used in any number required according to the circumstances. As a result, the dimensions of the storage system may be easily determined depending on the capacity required. Moreover, the storage system does not have an overall volume which is limited by the maximum volume transportable using a single exceptional transport means.

[0024] Advantageously, as a result of the method and the storage system according to the present invention, the quality control checks which need to be carried out on the storage system on-site are significantly reduced, since the single containers may be pre-fabricated and tested separately during or at the end of manufacture at the production site before transport.

[0025] Advantageously, the method and the storage system according to the present invention, while constituting a less disruptive solution, provide a storage system with a supporting surface which, for the same internal volume, is comparable to that of the systems currently used.

[0026] Advantageously, the supporting surface of the storage system according to the present invention is all the bigger, the greater the number of containers used. This result in a greater static stability.

[0027] Advantageously, with the method and the storage system according to the present invention, it is possible to achieve internal pressures inside the storage compartments which are higher than the pressures of conventional larger size reservoirs (Barlow's formula).

[0028] Advantageously, with the method and the storage system according to the present invention, it is possible to obtain manufacturing costs, including insulation costs, and installation costs which are comparable to those of the systems according to the prior art - or even less taking into account the additional costs such as piling, foundations and concealment structures.

[0029] Advantageously, the storage system according to the present invention may be easily disassembled and may also be easily modified in order to increase the capacity thereof.

[0030] Advantageously, in the event of malfunctioning or a problem affecting a container, with the method and the storage system according to the present invention it is possible to overcome any problem for example by bypassing the container (or containers) affected by said problem or by malfunctioning. This results in continuity of operation in the event of faults or technical problems, thus increasing the resilience of the system.

[0031] Advantageously, the method and the storage system according to the present invention have been designed to allow positioning of the modules vertically even where it is not possible to use overhead cranes. This feature means that erection of the storage system inside covered spaces is possible, resulting in a greater flexibility during installation and allowing efficient use of the already existing locations.

[0032] Advantageously, as a result of the modular nature of the present storage system, it is possible to accumulate a production stock which allows the construction of storage systems of varying capacity in a very short amount of time.

[0033] Advantageously, the modular nature of the present storage system allows adaptation to a vast range of configurations and environments, resulting in efficient storage even in spaces where there are height restrictions or other structural constraints.

[0034] Advantageously, the modular nature of the present storage system allows standardized pre-fabrication of container modules (i.e. according to stock and not commission-based), such that they may be supplied and installed very rapidly.

[0035] Advantageously, since in the storage system according to the present invention, only the temperature - and not the volume - of the liquid stored inside it varies, said storage system may be regarded as being an energy storage system. In fact, the volume of liquid entering the storage system is equal to the volume of liquid drawn from it.

[0036] Advantageously, the storage system according to the present invention has a single charging system - i.e. the filling line - which is designed to fill the entire volume of the storage system. In other words, it is not necessary to charge the single container modules by means of different charging systems.

[0037] Advantageously, the district heating plant according to the present invention allows any peak loads affecting the heat generating station to be reduced, with a consequent increase in the production capacity, as well as a greater operational flexibility, allowing rapid adaptation to variations in the demand for heated liquid.

[0038] Advantageously, with the district heating plant according to the present invention it is possible to achieve an optimized use of the resources with a positive impact on environmental sustainability.Preferred embodiments

[0039] The storage system is preferably a pressurized storage system or an atmospheric storage system.

[0040] "Pressurized" refers to a storage system comprising a pressurized housing able to withstand internal pressures (i.e. inside the storage compartment) ranging from atmospheric pressure to 25 bar, preferably from 1.05 bar to 16 bar.

[0041] "Atmsopheric" refers to a storage system in which the storage compartment is at the same pressure as atmospheric pressure.

[0042] In accordance with a preferred embodiment, the filling line 24 and / or the supply line 26 could be one or more bidirectional lines.

[0043] "Bidirectional" means that the line may convey the liquid in a first direction, but also in a second direction opposite to the first direction.

[0044] By way of example, a bidirectional line may be formed by means of two or more liquid conveying pipes arranged alongside each other, each pipe being passed through by the liquid in one direction only, opposite to the direction in the other pipe.

[0045] In accordance with a first preferred embodiment, the container modules 2 are connected together in series.

[0046] According to said embodiment, the header 34 (or 32) of a container module 2 located upstream in the direction of fluid flow is preferably connected to the distributor 32 (or 34) of a container module 2 located downstream in the direction of fluid flow.

[0047] Preferably, the distributor 32 (or 34) of the first container module 2 of said series is connected to the liquid source 10 via the filling line 24 or to the liquid user 12 via the supply line 26, and / or the header 34 (or 32) of the last container module 2 of the series is connected to the liquid user 12 via the supply line 26 or to the liquid source 10 via the filling line 24.

[0048] In accordance with a second preferred embodiment, the container modules 2 are connected together in parallel.

[0049] According to said embodiment, all the distributors 32 (or 34) of the container modules 2 are preferably connected to the liquid source 10 via the filling line 24 or to the liquid user 12 via the supply line 26, and all the headers 34 of the container modules 2 are connected to the liquid user 12 via the supply line 26 or to the liquid source 10 via the filling line 24.

[0050] Preferably, the filling line 24 comprises a plurality of first branches 56, each of said first branches 56 being connected to at least one distributor or header 32.

[0051] According to another preferred embodiment, the supply line 26 comprises a plurality of second branches 58, each of said second branches 58 being connected to at least one header or distributor 34.

[0052] It is pointed out that any of the liquid transport lines mentioned in this description - for example the filling line 24 and / or the supply line 26 and / or the conveying line 36 - could be at least partially made of heat-insulating material. Preferably, such a line could comprise at least one pipe for conveying the liquid (for example two pipes), at least one heat-insulating layer arranged around the pipe or pipes for conveying the liquid and made of an expanded foam material (for example expanded polyurethane foam), and at least one protective external pipe (for example made of polyethylene) which surrounds the heat-insulating layer.

[0053] In accordance with an advantageous embodiment, the storage system 1 comprises one or more bypass line(s) 38, 40, 42 arranged so as to connect a point upstream and at least one point downstream of at least one container module 2 so that the liquid does not pass through the storage compartment 4 of that container module 2. Preferably, each container module 2 is provided with at least one bypass line 38, 40, 42.

[0054] In accordance with different embodiments, said one or more bypass line(s) 38, 40, 42 is / are arranged so as to connect: the liquid source 10 to the storage compartment 4 of at least one container module 2 following a first container module 2 or preceding a last container module 2; and / or the storage compartments 4 of two container modules 2 separated (along the fluid flow line) by an intermediate module, without the liquid passing through the storage compartment of said intermediate container module; and / or the liquid user 12 to the storage compartment 4 of at least one container module 2 preceding a last container module 2 or following a first container module 2.

[0055] In the present description, "first" is understood as referring to the container module which receives the liquid directly from the liquid source 10 or from the liquid user 12.

[0056] In the present description, "last" is understood as referring to the final container module which supplies the liquid to the liquid user 12 or to the liquid source 10.

[0057] Preferably, the storage system 1 or each container module 2 comprises an insulated housing 60.

[0058] Therefore, the insulated housing could be arranged around the storage system 1 or around each container module 2. In the first embodiment, a single insulated housing 60 could accommodate a plurality of container modules. In the second embodiment, each container module comprises its own insulated housing.

[0059] In accordance with one embodiment, said insulated housing comprises - from the inside towards the outside - an optional metallic internal wall (for example made of steel), a thermal insulation layer (for example made of rock wool) and an external wall which encloses the heat insulation layer (preferably metallic, for example made of sheet metal or a polymer material). The metallic internal wall is preferably intended to make contact with the liquid received inside the container module.

[0060] Preferably, the district heating plant 50 comprises one or more expansions tanks or systems 48 which extend from the return line 46.

[0061] In accordance with one embodiment, the step (I) is preceded by the manufacture (or pre-manufacture) of container modules with predefined external dimensions and / or capacities. By way of example, the dimensions could be designed to maximize the capacity while complying with any transport constraints.

[0062] In accordance with another embodiment, the predefined length L is equal to or less than 13,500 mm, the predefined height H is equal to or less than 3000 mm, and the predefined width W is equal to or less than 3000 mm.

[0063] By way of example, the predefined length L ranges from about 8000 mm to 13,500 mm, the predefined height H ranges from about 2000 mm to 3000 mm, and the predefined width W ranges from about 2000 mm to 3000 mm.

[0064] The predefined height H and the predefined width W are selectable independently.

[0065] Preferably, but not necessarily, said container module 2 is an ISO container module.

[0066] An ISO container module is a container, the predefined length L, predefined height H and predefined width W of which are selected according to ISO standard 668:2020. The present description refers to this standard in the version valid at the priority date of the present application.

[0067] Preferably, the predefined length L is selected from: 13,716 mm (45 ft), 12,192 mm (40 ft), 9125 mm (30 ft), 6058 mm (20 ft), or 2991 mm (10 ft). The predefined height H is selected from: 1295 mm (4 ft 3 in), 2438 mm (8 ft), 2591 mm (8 ft 6 in), or 2896 mm (9 ft 6 in). The predefined width W is 2438 mm (8 ft).

[0068] More preferably, the predefined length L is 6058 mm, the predefined height is 2438 mm, and the predefined width W is 2438 mm.

[0069] In accordance with a preferred embodiment, each container module 2 comprises a frame 6 in the form of a right-angled parallelepiped.

[0070] Said frame 6 delimits preferably a smaller base 8 of the right-angled parallelepiped, arranged at right angles to the predefined length L, and a larger base 14 of the right-angled parallelepiped, arranged at right angles to the smaller base 8.

[0071] Advantageously, the container 2 rests on the larger base 14 during step (I) and on the smaller base 8 at the end of step (II).

[0072] In accordance with various embodiments, the storage compartment 4 could have a cross-section - orthogonal to the length L - which is polygonal (for example square or rectangular) or circular.

[0073] Preferably, the frame 6 comprises corner fittings 22 for rotatable locking devices (e.g. "twistlocks") according to ISO standard 1161:2016. This standard is to be understood as being the version valid at the priority date of the present application.

[0074] As regards step (III), the fluid connection is in series or in parallel according to different embodiments.

[0075] The series or parallel connection preferably comprises drawing off the liquid from a vertically upper portion 16 of a storage compartment 4 of a preceding container 2 (i.e. container upstream in the direction of flow of the liquid) and supplying the liquid thus drawn off to a vertically lower portion 18 of a storage compartment 4 of a following container (i.e. container downstream in the direction of flow of the liquid).

[0076] The series or parallel connection preferably comprises drawing off the liquid from a vertically lower portion 18 of a storage compartment 4 of a preceding container module 2 and supplying the liquid thus drawn off to a vertically upper portion 16 of a storage compartment 4 of a following container module 2.

[0077] Preferably, the method comprises a step: (V) realizing a mechanical connection 20 between the containers 2 of step (II) so as to provide a monolithic storage system 1.

[0078] By way of example, the mechanical connection 20 comprises one or more woodwork elements.

[0079] Advantageously, this mechanical connection is configured to fix and support concealment elements (for example panels) for concealing said storage system 1.

[0080] In accordance with a preferred embodiment, one or more mechanical connections 20 is / are arranged between frames 6 or between corner fittings 22 of adjacent containers 2.

[0081] Preferably, the storage system 1 is used as a thermal storage system of a district heating plant.

[0082] Preferably, the liquid is a liquid - for example water - heated to a temperature ≥ 50°C, more preferably ≥ 70°C, even more preferably comprised from 70°C to 140°C, for example comprised from 80°C to 135°C.

[0083] In accordance with a preferred embodiment, the method comprises a step: (VI) providing an external covering for said storage system of step (II) or step (V).

[0084] In accordance with various embodiments, the external covering could consist of elements and materials suitable for imparting one or more of the following characteristics: thermal insulation, and / or concealment, and / or sound-proofing, and / or flame and / or fire resistance.

[0085] The advantages of the invention will emerge even more clearly from the detailed description given below based on the attached figures provided by way of example and therefore of a non-limiting nature.Description of the figures

[0086] Fig. 1.A, Fig. 1 .B., Fig. 1.C show different embodiments of containers which can be used in the method and the storage system according to the present invention, in which containers are oriented as in step (I); Fig. 2 shows a container which can be used in the method and the storage system according to the present invention, oriented as at the end of step (II); Fig. 3 and Fig. 4 show different embodiments of storage systems according to the present invention; Fig. 5.A shows a schematic illustration of a storage system according to the present invention, in which the containers are connected together in series in accordance with a first embodiment and in a condition for charging the storage system; Fig. 5.B shows a schematic illustration of a storage system according to the present invention, in which the containers are connected together in series in accordance with a first embodiment and in a condition for discharging the storage system; Fig. 6.A shows a schematic illustration of a storage system according to the present invention, in which the containers are connected together in parallel in accordance with a first embodiment and in a condition for charging the storage system; Fig. 6.B shows a schematic illustration of a storage system according to the present invention, in which the containers are connected together in parallel in accordance with a first embodiment and in a condition for discharging the storage system; Fig. 7.A shows a schematic illustration of a storage system according to the present invention, in which the containers are connected together in series in accordance with a second embodiment and in a condition for charging the storage system; Fig. 7.B shows a schematic illustration of a storage system according to the present invention, in which the containers are connected together in series in accordance with a second embodiment and in a condition for discharging the storage system; Fig. 8.A shows a schematic illustration of a storage system according to the present invention, in which the containers are connected together in parallel in accordance with a second embodiment and in a condition for charging the storage system; Fig. 8.B shows a schematic illustration of a storage system according to the present invention, in which the containers are connected together in parallel in accordance with a second embodiment and in a condition for discharging the storage system; Fig. 9.A shows a diagram of a district heating plant in accordance with a first embodiment in which the storage system is pressurized and in which the storage system is in a charging condition; Fig. 9.A shows a diagram of a district heating plant in accordance with a first embodiment in which the storage system is pressurized and in which the storage system is in a discharging condition; Fig. 10.A shows a diagram of a district heating plant in accordance with a second embodiment in which the storage system is at atmospheric pressure and in which the storage system is in a charging condition; Fig. 10.A shows a diagram of a district heating plant in accordance with a second embodiment in which the storage system is at atmospheric pressure and in which the storage system is in a discharging condition; Fig. 11 shows a view from above of a storage system according to a possible embodiment comprising a plurality of container modules accommodated inside a single insulated housing. Detailed description of the invention according to a preferred embodiment

[0087] Fig. 1.A, Fig. 1.B and Fig. 1.C show container modules in accordance with possible embodiments. For each of them the system of reference coordinates of the predefined length L, predefined height H and predefined width W are shown. During the transport in step (I) the predefined length L is arranged substantially horizontally.

[0088] Each container module 2 comprises a frame 6 in the form of a right-angled parallelepiped, which circumscribes a storage compartment 4 for a liquid, preferably water.

[0089] The frame 6 delimits a smaller base 8 and a larger base 14. The smaller base 8 of the right-angled parallelepiped is arranged at right angles to the predefined length L. The larger base 14 is arranged at right angles to the smaller base 8.

[0090] During step (I), the container module 2 rests on the larger base 14.

[0091] At the end of step (II), the container modules 2 rests on the smaller base 8 owing to the rotation, and the predefined length extends vertically. In this connection see Fig. 2.

[0092] The storage compartment 4 may have a cross-section - orthogonal to the length L - which is polygonal (for example square or rectangular) or circular.

[0093] In the embodiment of Fig. 1.C, corner fittings 22 of the frame 6 for rotatable locking devices (so-called "twistlocks") - according to ISO standard 1161:2016 - of a container module 2 can be seen.

[0094] Fig. 2 shows a generic container module 2 rotated - at the end of step (III) - with respect to step (I), so that the predefined length L is oriented substantially vertically.

[0095] Fig. 3 and Fig. 4 show two storage systems 1 in accordance with different embodiments. Although these figures show, respectively, two and four container modules 2, this number is not limiting for the purposes of the present invention.

[0096] The container modules 2 in Fig. 3 are arranged alongside each other and spaced from each other (i.e. not in mutual contact).

[0097] The container modules 2 in Fig. 4 make mutual contact by means of side faces 30 and by means of respective longitudinal edges 28.

[0098] One or more mechanical connection(s) 20 join together the plurality of container modules 2 so as to provide a monolithic storage system 1. This / these mechanical connection(s) 20 is / are connected to the frames 2 and / or to the corner fittings 22 (when available).

[0099] Fig. 5.A and Fig. 6.A show two schematic illustrations of the fluid connections between container modules 4, which are respectively arranged in series or in parallel.

[0100] In the series connection - Fig. 5.A - the liquid supplied from a liquid source 10 is introduced into the first container module 2 in a vertically lower portion 18 of the storage compartment 4. The liquid is supplied by means of a distributor 32 located inside the storage compartment 4. A header 34 is located in a vertically upper portion 16 of the storage compartment 4 of the same container module 2 and conveys the liquid from the storage compartment 4 of the first container module 2 to the storage compartment 4 of the second container module 2 - in the direction of flow of the liquid - via a conveying line 36.

[0101] The liquid crosses the storage compartment 4 of the second container module 2 and of the following third container module 2 in the same way as described for the first container module 2.

[0102] In the fourth container module 2, the liquid entering into the storage compartment 4 through the distributor 32 flows out through the header 34. This outflowing liquid could be supplied to one or more successive container modules 2 or - according to the embodiment shown - is supplied to a liquid user 12 via a supply line 26.

[0103] In the parallel connection - Fig. 6.A - the liquid supplied from a liquid source 10 is introduced parallel into the container modules 2 in vertically lower portions 18 of each storage compartment 4. The broken lines extending to the left of the first module on the left indicate that there could more than four modules.

[0104] The liquid is supplied by means of distributors 32 in the same way as for the preceding embodiment. A header 34 is located in a vertically upper portion 16 of each storage compartment 4 and conveys the liquid from the storage compartment 4 of each container module 2 to the liquid user 12 via a supply line 26.

[0105] Fig. 5.B and Fig. 6.B show two schematic illustrations of the fluid connections between container modules 4, which are arranged respectively in series or in parallel, corresponding to Fig. 5.A and Fig. 6.A, but in which the direction of transit of the liquid is reversed.

[0106] In the series connection - Fig. 5.B - the liquid supplied from the liquid user 12 is introduced into the first container module 2 on the right (with reference to the schematic illustration) in a vertically upper portion 16 of the storage compartment 4. The liquid is supplied by means of a distributor 34 located inside the storage compartment 4. A header 32 is located in a vertically lower portion 18 of the storage compartment 4 of the same container module 2 and conveys the liquid from the storage compartment 4 of the first container module 2 to the storage compartment 4 of the second container module 2 - in the direction of flow of the liquid - via a conveying line 36.

[0107] The liquid crosses the storage compartment 4 of the second container module 2 and of the following third container module 2 in the same way as described for the first container module 2.

[0108] In the fourth container module 2, the liquid entering into the storage compartment 4 through the distributor 34 flows out through the header 32. This outflowing liquid is supplied to the liquid source 10 via the supply line 26.

[0109] In the parallel connection - Fig. 6.B - the liquid supplied from the liquid user 12 is introduced parallel into the container modules 2 in vertically upper portions 16 of each storage compartment 4. The broken lines extending to the left of the last module on the left indicate that there could more than four modules.

[0110] The liquid is supplied by means of distributors 34 in the same way as for the preceding embodiment. A header 32 is located in a vertically lower portion 18 of each storage compartment 4 and conveys the liquid from the storage compartment 4 of each container module 2 to the liquid source 10 via the filling line 24.

[0111] Fig. 7.A, Fig. 7.B, Fig. 8.A and Fig. 8.B show schematic illustrations of the fluid connections between container modules 4, in series or in parallel, in accordance with further embodiments.

[0112] These embodiments differ from the corresponding Fig. 5.A, Fig. 5.B and Fig. 6.A, Fig. 6.B, respectively, owing to the presence of at least one bypass line which is arranged so as to connect a point upstream and at least one point downstream of at least one container module 2. It is pointed out that the presence of one or more bypass lines necessarily involves the presence of valves and actuating devices which, for the sake of simpler description, are neither shown in the figures nor discussed in this description.

[0113] In particular, the embodiment of Fig. 7.A shows a first bypass line 38 which extends between a point downstream of the liquid source and upstream of the first container module 2 and which conveys the liquid into at least one point downstream of the first container module 2. By way of example, this downstream point could be arranged between the first and the second container modules and / or between the second and third container modules and / or between the third and fourth container modules and / or downstream of the fourth container module.

[0114] A second bypass line 40 places in fluid communication the storage compartments 4 of two container modules 2 separated by an intermediate container module, without the liquid passing through the storage compartment of said intermediate container module. In the example shown in Fig. 7, the intermediate container module is the second from the left, so that the liquid drawn off from the storage compartment 4 of the first container module on the left via the conveying line 36 is supplied downstream of the second container module without passing through the storage compartment of the second container module.

[0115] A third bypass line 42 places in fluid communication the storage compartment 4 of at least one container module 2 preceding a last container module 2 with the liquid user 12.

[0116] Considerations similar to those of Fig. 7A apply to the embodiment of Fig. 8.A, although the arrangement of the container modules is in parallel.

[0117] In the example shown in Fig. 8.A, the intermediate container module is the second one from the right, so that the liquid drawn downstream of the first container module (first from the right) is supplied downstream of the second container module.

[0118] Since it consists of a parallel arrangement, the bypass lines 40, 42 of Fig. 8.A are also arranged along the supply line 26.

[0119] The embodiments of Fig. 7.B and Fig. 8.B correspond to the embodiments Fig. 7.A and Fig. 8.A, but the direction of transit of the liquid is reversed.

[0120] Fig. 9.A and Fig. 10.A show two diagrams of a district heating plant in accordance with various embodiments in which the storage system is of pressurized type or the atmospheric (non-pressurized) type, respectively.

[0121] The heated liquid is produced in a heat generating station 44 which performs the function of a heat source 10. The heat generating station 44 and the storage system 1 are connected via the filling line 24. The storage system 1 is instead connected to one or more liquid users 12 via at least one supply line 26.

[0122] The heat generating station 44 and said one or more liquid users 12 are connected via at least one direct supply line 52, which does pass through (i.e. bypasses) the storage system 1.

[0123] Said one or more liquid users 12 and the heat generating station 44 are also connected via at least one return line 46 so as to form a circuit.

[0124] In this way, the liquid heated in the heat generating station 44 flows towards said liquid user(s) 12 via the storage system 1 and / or via the direct supply line 52. After said liquid has been at least partially cooled at said liquid user(s) 12, said at least partially cooled liquid returns to the heat generating station 44 via the return line 46.

[0125] Along the return line 46 there is arranged a first expansion tank 48, which receives the at least partially cooled liquid from said return line and which supplies said liquid to the heat generating station 44.

[0126] In the embodiment shown, at least one expansion tank 48' is arranged upstream of a point in which an additional line 54 - which connects the storage system 1 and the return line 1 - enters into the return line 46. Although the additional line 54 is shown as exiting from the first container module 2, said feature is not limiting in that the additional line 54 could be connected to any container module 2 different from the first module or in addition to the first module.

[0127] The diagram of Fig. 9.B differs from the diagram of Fig. 9.A at least in that the liquid may be conveyed from the storage system to the heat generating station 44 via the filling line 24, in that the liquid may be conveyed from the liquid user 12 to the storage system 1 via the supply line 26, and in that the liquid may be conveyed from the return line 46 to the storage system 1 via the additional line 54.

[0128] The diagram of Fig. 10.A differs from the diagram of Fig. 9.A at least because of the absence of expansion tanks and obviously because the storage system 1 is not pressurized.

[0129] The diagram of Fig. 10.B differs from the diagram of Fig. 10.A at least in that the liquid may be conveyed from the storage system to the heat generating station 44 via the filling line 24, in that the liquid may be conveyed from the liquid user 12 to the storage system 1 via the supply line 26, and in that the liquid may be conveyed from the return line 46 to the storage system 1 via the additional line 54.

[0130] Fig. 11 shows a top plan view of a storage system according to a possible embodiment.

[0131] Said figure clearly shows the presence of a single insulated housing 60 which accommodates a plurality of container modules 2.

[0132] This figure also clearly shows piping 62 which provide a fluid connection between pairs of adjacent container modules 2.

[0133] Even though not previously specified, a person skilled in the art may, drawing on the typical expertise in the sector, vary or replace some of the aspects indicated above with other technically equivalent elements.

[0134] These variation or replacements also fall within the scope of the following claims.

[0135] Moreover, any alternative illustrated in relation to a particular embodiment may be implemented independently of the other variants described.LIST OF REFERENCE NUMBERS

[0136] 1storage system 2container module 4storage compartment 6frame 8smaller base 10liquid source 12liquid user 14larger base 16vertically upper portion 18vertically lower portion 20mechanical connection 22corner fitting 24filling line 26supply line 28longitudinal edge 30side face 32distributor or header 34header or distributor 36conveying line 38(first) bypass line 40(second) bypass line 42(third) bypass line 44heat generating station 46return line 48expansion tank 50district heating plant 52direct supply line 54additional line 56first branch 58second branch 60insulated housing 62piping Hpredefined height Lpredefined length Wpredefined width

Examples

Embodiment Construction

[0087]Fig. 1.A, Fig. 1.B and Fig. 1.C show container modules in accordance with possible embodiments. For each of them the system of reference coordinates of the predefined length L, predefined height H and predefined width W are shown. During the transport in step (I) the predefined length L is arranged substantially horizontally.

[0088]Each container module 2 comprises a frame 6 in the form of a right-angled parallelepiped, which circumscribes a storage compartment 4 for a liquid, preferably water.

[0089]The frame 6 delimits a smaller base 8 and a larger base 14. The smaller base 8 of the right-angled parallelepiped is arranged at right angles to the predefined length L. The larger base 14 is arranged at right angles to the smaller base 8.

[0090]During step (I), the container module 2 rests on the larger base 14.

[0091]At the end of step (II), the container modules 2 rests on the smaller base 8 owing to the rotation, and the predefined length extends vertically. In this connection see...

Field of the invention

[0001] The invention relates to the sector of methods for building storage systems for liquids, preferably for use in district heating plants.Prior art

[0002] The use of thermal storage systems has been known for some time.

[0003] These storage systems are commonly used to store heated liquids when the demand for heat is low and to release these liquids when the demand for heat increases.

[0004] Thermal storage systems usually have a significant vertical height (for example 20 metres or more) and this results in a series of problems including risks: of a structural nature, with the need to provide suitable piling and foundations (in order to prevent critical situations due to earthquakes, wind and / or high weight); of a regulatory nature, in view of the fact that a storage system is a static structure which requires special permission for construction thereof; of a constructional nature, since as well as occupying a large area (roughly 200 m 3< ) it is also required to build a storage reservoir on-site with construction work lasting at least about 6-7 months; of a landscaping nature, with the need to erect concealment structures; and of a logistical nature, because of the need to transport equipment using exceptional transport.

[0005] Prior art documents include WO 2010 / 060147 A1 and AU 2019 229 103 A1.

[0006] The Applicant, after a long and in-depth R&D investigation work, has developed a storage system, a district heating plant and a method which are able to provide a suitable response to the existing limitations, drawbacks and problems. In particular, the Applicant has developed a building method, a storage system and a district heating plant which use a modular system of containers which may be generally arranged on existing foundations, which has a limited impact on the landscape and which, also from a logistical point of view, may be implemented without the use of exceptional transport.Summary of the invention

[0007] The object of the invention is to overcome the aforementioned drawbacks of the prior art.

[0008] Therefore, the present invention relates to a storage system which comprises a plurality of container modules and wherein: each container module delimits a storage compartment for a liquid; each container module has a predefined length, predefined height and predefined width; said plurality of container modules is arranged in an adjacent or mutually contacting position; the predefined length of each container module is oriented substantially vertically; the storage compartments of the container modules are connected together with a fluid connection; optionally said storage system comprises a filling line for filling said storage system by means of a liquid source and, preferably, a supply line connecting said storage system to a liquid user; wherein the container module comprises: (a) at least one distributor or header located in a vertically lower portion of the storage compartment for supplying the liquid to the container module or for conveying the liquid outside of the storage compartment; and (b) at least one header or distributor located in a vertically upper portion of the storage compartment for conveying the liquid outside of the storage compartment or for supplying the liquid to the container module.

[0009] It is pointed out that the expression "distributor" in case (a) and "header" in case (b) are to be understood as being such in an operating condition where the container module is supplied with the liquid from the distributor and that the liquid is drawn from the storage compartment via the header. This operating condition occurs, for example, during charging of the storage system by means of the liquid source.

[0010] Nevertheless, in a different operating condition ("discharging" of the storage system), the filling line 24 and the supply line 26 could be configured, respectively, to convey the liquid from the storage system 1 to the liquid source 10 and to convey the liquid form the liquid user 12 to the storage system 1.

[0011] In a different operating condition, the element called "distributor" with reference to charging of the storage system acts as a header during discharging of the storage system, while the element called "header" during charging of the storage system acts as a distributor during discharging of the storage system. This is due to the fact that the first one of these elements is located in a vertically lower portion of the storage compartment and the second one of these elements is located in a vertically upper portion of the storage compartment. From the structural point of view of the single container module 2 and the positioning of these elements inside the storage compartment there are no differences with respect to charging of the storage system, since when changing from charging to discharging only the direction of displacement of the liquid inside the storage system 1 is reversed.

[0012] Expressed in other words, the "header" in case (a) and the "distributor" in case (b) are to be understood as such during discharging of the storage system, and therefore in the operating condition in which the container module is supplied with the liquid from the distributor and the liquid is drawn from the storage compartment via the header.

[0013] The present invention also relates to a district heating plant comprising: said storage system; a heat generating station having the function of said liquid source for the heated liquid; wherein the storage system and the heat generating station are connected via the filling line and wherein the storage system is connected to one or more liquid users by means of at least one supply line; and at least one return line which connects said one or more liquid users to the heat generating station so as to form a circuit.

[0014] The present invention also relates to a method for building said storage system for a liquid. Said method comprises the following steps: (I) transporting a plurality of container modules; wherein each container module delimits a storage compartment for a liquid; wherein each container module has a predefined length, predefined height and predefined width; wherein, during step (I), the predefined length is oriented substantially horizontally; (II) arranging said plurality of container modules in an adjacent or mutually contacting position, wherein at least some of said container modules (for example, each container module) is rotated with respect to step (I) so that said predefined length is oriented substantially vertically; (III) realizing a fluid connection between the storage compartments of the container modules of step (II) so as to provide said storage system; IV) optionally filling the storage system of step (III) by means of a liquid source and, preferably, supplying a liquid user by means of the filled storage system.

[0015] The present invention also relates to use of said storage system as a thermal storage system.Advantages of the invention

[0016] The invention has the advantages which are described below.

[0017] Advantageously, the method and the storage system according to the present invention use standard size container modules which do not require special measures nor authorizations for transport thereof.

[0018] Advantageously, the method and the storage system according to the present invention have been designed such that a maximum overall height is not exceeded. As a result, said storage system is subject to a limited seismic risk, does not need to be covered with particularly extensive landscape concealment structures and, also as regards the installation costs, does not require the construction of special foundations or support piling. For example, the present storage system may be positioned on pre-existing platforms.

[0019] Advantageously, the method and the storage system according to the present invention allows construction on-site in a particularly short amount of time, of about one day, compared to the months which are required for the construction of a storage system according to the prior art.

[0020] Advantageously, the method and the storage system according to the present invention reduce and eliminate problems associated with execution of the work carried out at significant heights.

[0021] Advantageously, the method and the storage system according to the present invention do not require installation worksites or work which are particularly disruptive.

[0022] Advantageously, the method and storage system according to the present invention also solve the problem of thermal stratification (thermoclines) which conventionally occurs in the case of large-volume reservoirs. The present storage system guarantees, in fact, a uniform and improved distribution of the heat.

[0023] Advantageously, the method and the storage system according to the present invention use containers which constitute modular elements which can be used in any number required according to the circumstances. As a result, the dimensions of the storage system may be easily determined depending on the capacity required. Moreover, the storage system does not have an overall volume which is limited by the maximum volume transportable using a single exceptional transport means.

[0024] Advantageously, as a result of the method and the storage system according to the present invention, the quality control checks which need to be carried out on the storage system on-site are significantly reduced, since the single containers may be pre-fabricated and tested separately during or at the end of manufacture at the production site before transport.

[0025] Advantageously, the method and the storage system according to the present invention, while constituting a less disruptive solution, provide a storage system with a supporting surface which, for the same internal volume, is comparable to that of the systems currently used.

[0026] Advantageously, the supporting surface of the storage system according to the present invention is all the bigger, the greater the number of containers used. This result in a greater static stability.

[0027] Advantageously, with the method and the storage system according to the present invention, it is possible to achieve internal pressures inside the storage compartments which are higher than the pressures of conventional larger size reservoirs (Barlow's formula).

[0028] Advantageously, with the method and the storage system according to the present invention, it is possible to obtain manufacturing costs, including insulation costs, and installation costs which are comparable to those of the systems according to the prior art - or even less taking into account the additional costs such as piling, foundations and concealment structures.

[0029] Advantageously, the storage system according to the present invention may be easily disassembled and may also be easily modified in order to increase the capacity thereof.

[0030] Advantageously, in the event of malfunctioning or a problem affecting a container, with the method and the storage system according to the present invention it is possible to overcome any problem for example by bypassing the container (or containers) affected by said problem or by malfunctioning. This results in continuity of operation in the event of faults or technical problems, thus increasing the resilience of the system.

[0031] Advantageously, the method and the storage system according to the present invention have been designed to allow positioning of the modules vertically even where it is not possible to use overhead cranes. This feature means that erection of the storage system inside covered spaces is possible, resulting in a greater flexibility during installation and allowing efficient use of the already existing locations.

[0032] Advantageously, as a result of the modular nature of the present storage system, it is possible to accumulate a production stock which allows the construction of storage systems of varying capacity in a very short amount of time.

[0033] Advantageously, the modular nature of the present storage system allows adaptation to a vast range of configurations and environments, resulting in efficient storage even in spaces where there are height restrictions or other structural constraints.

[0034] Advantageously, the modular nature of the present storage system allows standardized pre-fabrication of container modules (i.e. according to stock and not commission-based), such that they may be supplied and installed very rapidly.

[0035] Advantageously, since in the storage system according to the present invention, only the temperature - and not the volume - of the liquid stored inside it varies, said storage system may be regarded as being an energy storage system. In fact, the volume of liquid entering the storage system is equal to the volume of liquid drawn from it.

[0036] Advantageously, the storage system according to the present invention has a single charging system - i.e. the filling line - which is designed to fill the entire volume of the storage system. In other words, it is not necessary to charge the single container modules by means of different charging systems.

[0037] Advantageously, the district heating plant according to the present invention allows any peak loads affecting the heat generating station to be reduced, with a consequent increase in the production capacity, as well as a greater operational flexibility, allowing rapid adaptation to variations in the demand for heated liquid.

[0038] Advantageously, with the district heating plant according to the present invention it is possible to achieve an optimized use of the resources with a positive impact on environmental sustainability.Preferred embodiments

[0039] The storage system is preferably a pressurized storage system or an atmospheric storage system.

[0040] "Pressurized" refers to a storage system comprising a pressurized housing able to withstand internal pressures (i.e. inside the storage compartment) ranging from atmospheric pressure to 25 bar, preferably from 1.05 bar to 16 bar.

[0041] "Atmsopheric" refers to a storage system in which the storage compartment is at the same pressure as atmospheric pressure.

[0042] In accordance with a preferred embodiment, the filling line 24 and / or the supply line 26 could be one or more bidirectional lines.

[0043] "Bidirectional" means that the line may convey the liquid in a first direction, but also in a second direction opposite to the first direction.

[0044] By way of example, a bidirectional line may be formed by means of two or more liquid conveying pipes arranged alongside each other, each pipe being passed through by the liquid in one direction only, opposite to the direction in the other pipe.

[0045] In accordance with a first preferred embodiment, the container modules 2 are connected together in series.

[0046] According to said embodiment, the header 34 (or 32) of a container module 2 located upstream in the direction of fluid flow is preferably connected to the distributor 32 (or 34) of a container module 2 located downstream in the direction of fluid flow.

[0047] Preferably, the distributor 32 (or 34) of the first container module 2 of said series is connected to the liquid source 10 via the filling line 24 or to the liquid user 12 via the supply line 26, and / or the header 34 (or 32) of the last container module 2 of the series is connected to the liquid user 12 via the supply line 26 or to the liquid source 10 via the filling line 24.

[0048] In accordance with a second preferred embodiment, the container modules 2 are connected together in parallel.

[0049] According to said embodiment, all the distributors 32 (or 34) of the container modules 2 are preferably connected to the liquid source 10 via the filling line 24 or to the liquid user 12 via the supply line 26, and all the headers 34 of the container modules 2 are connected to the liquid user 12 via the supply line 26 or to the liquid source 10 via the filling line 24.

[0050] Preferably, the filling line 24 comprises a plurality of first branches 56, each of said first branches 56 being connected to at least one distributor or header 32.

[0051] According to another preferred embodiment, the supply line 26 comprises a plurality of second branches 58, each of said second branches 58 being connected to at least one header or distributor 34.

[0052] It is pointed out that any of the liquid transport lines mentioned in this description - for example the filling line 24 and / or the supply line 26 and / or the conveying line 36 - could be at least partially made of heat-insulating material. Preferably, such a line could comprise at least one pipe for conveying the liquid (for example two pipes), at least one heat-insulating layer arranged around the pipe or pipes for conveying the liquid and made of an expanded foam material (for example expanded polyurethane foam), and at least one protective external pipe (for example made of polyethylene) which surrounds the heat-insulating layer.

[0053] In accordance with an advantageous embodiment, the storage system 1 comprises one or more bypass line(s) 38, 40, 42 arranged so as to connect a point upstream and at least one point downstream of at least one container module 2 so that the liquid does not pass through the storage compartment 4 of that container module 2. Preferably, each container module 2 is provided with at least one bypass line 38, 40, 42.

[0054] In accordance with different embodiments, said one or more bypass line(s) 38, 40, 42 is / are arranged so as to connect: the liquid source 10 to the storage compartment 4 of at least one container module 2 following a first container module 2 or preceding a last container module 2; and / or the storage compartments 4 of two container modules 2 separated (along the fluid flow line) by an intermediate module, without the liquid passing through the storage compartment of said intermediate container module; and / or the liquid user 12 to the storage compartment 4 of at least one container module 2 preceding a last container module 2 or following a first container module 2.

[0055] In the present description, "first" is understood as referring to the container module which receives the liquid directly from the liquid source 10 or from the liquid user 12.

[0056] In the present description, "last" is understood as referring to the final container module which supplies the liquid to the liquid user 12 or to the liquid source 10.

[0057] Preferably, the storage system 1 or each container module 2 comprises an insulated housing 60.

[0058] Therefore, the insulated housing could be arranged around the storage system 1 or around each container module 2. In the first embodiment, a single insulated housing 60 could accommodate a plurality of container modules. In the second embodiment, each container module comprises its own insulated housing.

[0059] In accordance with one embodiment, said insulated housing comprises - from the inside towards the outside - an optional metallic internal wall (for example made of steel), a thermal insulation layer (for example made of rock wool) and an external wall which encloses the heat insulation layer (preferably metallic, for example made of sheet metal or a polymer material). The metallic internal wall is preferably intended to make contact with the liquid received inside the container module.

[0060] Preferably, the district heating plant 50 comprises one or more expansions tanks or systems 48 which extend from the return line 46.

[0061] In accordance with one embodiment, the step (I) is preceded by the manufacture (or pre-manufacture) of container modules with predefined external dimensions and / or capacities. By way of example, the dimensions could be designed to maximize the capacity while complying with any transport constraints.

[0062] In accordance with another embodiment, the predefined length L is equal to or less than 13,500 mm, the predefined height H is equal to or less than 3000 mm, and the predefined width W is equal to or less than 3000 mm.

[0063] By way of example, the predefined length L ranges from about 8000 mm to 13,500 mm, the predefined height H ranges from about 2000 mm to 3000 mm, and the predefined width W ranges from about 2000 mm to 3000 mm.

[0064] The predefined height H and the predefined width W are selectable independently.

[0065] Preferably, but not necessarily, said container module 2 is an ISO container module.

[0066] An ISO container module is a container, the predefined length L, predefined height H and predefined width W of which are selected according to ISO standard 668:2020. The present description refers to this standard in the version valid at the priority date of the present application.

[0067] Preferably, the predefined length L is selected from: 13,716 mm (45 ft), 12,192 mm (40 ft), 9125 mm (30 ft), 6058 mm (20 ft), or 2991 mm (10 ft). The predefined height H is selected from: 1295 mm (4 ft 3 in), 2438 mm (8 ft), 2591 mm (8 ft 6 in), or 2896 mm (9 ft 6 in). The predefined width W is 2438 mm (8 ft).

[0068] More preferably, the predefined length L is 6058 mm, the predefined height is 2438 mm, and the predefined width W is 2438 mm.

[0069] In accordance with a preferred embodiment, each container module 2 comprises a frame 6 in the form of a right-angled parallelepiped.

[0070] Said frame 6 delimits preferably a smaller base 8 of the right-angled parallelepiped, arranged at right angles to the predefined length L, and a larger base 14 of the right-angled parallelepiped, arranged at right angles to the smaller base 8.

[0071] Advantageously, the container 2 rests on the larger base 14 during step (I) and on the smaller base 8 at the end of step (II).

[0072] In accordance with various embodiments, the storage compartment 4 could have a cross-section - orthogonal to the length L - which is polygonal (for example square or rectangular) or circular.

[0073] Preferably, the frame 6 comprises corner fittings 22 for rotatable locking devices (e.g. "twistlocks") according to ISO standard 1161:2016. This standard is to be understood as being the version valid at the priority date of the present application.

[0074] As regards step (III), the fluid connection is in series or in parallel according to different embodiments.

[0075] The series or parallel connection preferably comprises drawing off the liquid from a vertically upper portion 16 of a storage compartment 4 of a preceding container 2 (i.e. container upstream in the direction of flow of the liquid) and supplying the liquid thus drawn off to a vertically lower portion 18 of a storage compartment 4 of a following container (i.e. container downstream in the direction of flow of the liquid).

[0076] The series or parallel connection preferably comprises drawing off the liquid from a vertically lower portion 18 of a storage compartment 4 of a preceding container module 2 and supplying the liquid thus drawn off to a vertically upper portion 16 of a storage compartment 4 of a following container module 2.

[0077] Preferably, the method comprises a step: (V) realizing a mechanical connection 20 between the containers 2 of step (II) so as to provide a monolithic storage system 1.

[0078] By way of example, the mechanical connection 20 comprises one or more woodwork elements.

[0079] Advantageously, this mechanical connection is configured to fix and support concealment elements (for example panels) for concealing said storage system 1.

[0080] In accordance with a preferred embodiment, one or more mechanical connections 20 is / are arranged between frames 6 or between corner fittings 22 of adjacent containers 2.

[0081] Preferably, the storage system 1 is used as a thermal storage system of a district heating plant.

[0082] Preferably, the liquid is a liquid - for example water - heated to a temperature ≥ 50°C, more preferably ≥ 70°C, even more preferably comprised from 70°C to 140°C, for example comprised from 80°C to 135°C.

[0083] In accordance with a preferred embodiment, the method comprises a step: (VI) providing an external covering for said storage system of step (II) or step (V).

[0084] In accordance with various embodiments, the external covering could consist of elements and materials suitable for imparting one or more of the following characteristics: thermal insulation, and / or concealment, and / or sound-proofing, and / or flame and / or fire resistance.

[0085] The advantages of the invention will emerge even more clearly from the detailed description given below based on the attached figures provided by way of example and therefore of a non-limiting nature.Description of the figures

[0086] Fig. 1.A, Fig. 1 .B., Fig. 1.C show different embodiments of containers which can be used in the method and the storage system according to the present invention, in which containers are oriented as in step (I); Fig. 2 shows a container which can be used in the method and the storage system according to the present invention, oriented as at the end of step (II); Fig. 3 and Fig. 4 show different embodiments of storage systems according to the present invention; Fig. 5.A shows a schematic illustration of a storage system according to the present invention, in which the containers are connected together in series in accordance with a first embodiment and in a condition for charging the storage system; Fig. 5.B shows a schematic illustration of a storage system according to the present invention, in which the containers are connected together in series in accordance with a first embodiment and in a condition for discharging the storage system; Fig. 6.A shows a schematic illustration of a storage system according to the present invention, in which the containers are connected together in parallel in accordance with a first embodiment and in a condition for charging the storage system; Fig. 6.B shows a schematic illustration of a storage system according to the present invention, in which the containers are connected together in parallel in accordance with a first embodiment and in a condition for discharging the storage system; Fig. 7.A shows a schematic illustration of a storage system according to the present invention, in which the containers are connected together in series in accordance with a second embodiment and in a condition for charging the storage system; Fig. 7.B shows a schematic illustration of a storage system according to the present invention, in which the containers are connected together in series in accordance with a second embodiment and in a condition for discharging the storage system; Fig. 8.A shows a schematic illustration of a storage system according to the present invention, in which the containers are connected together in parallel in accordance with a second embodiment and in a condition for charging the storage system; Fig. 8.B shows a schematic illustration of a storage system according to the present invention, in which the containers are connected together in parallel in accordance with a second embodiment and in a condition for discharging the storage system; Fig. 9.A shows a diagram of a district heating plant in accordance with a first embodiment in which the storage system is pressurized and in which the storage system is in a charging condition; Fig. 9.A shows a diagram of a district heating plant in accordance with a first embodiment in which the storage system is pressurized and in which the storage system is in a discharging condition; Fig. 10.A shows a diagram of a district heating plant in accordance with a second embodiment in which the storage system is at atmospheric pressure and in which the storage system is in a charging condition; Fig. 10.A shows a diagram of a district heating plant in accordance with a second embodiment in which the storage system is at atmospheric pressure and in which the storage system is in a discharging condition; Fig. 11 shows a view from above of a storage system according to a possible embodiment comprising a plurality of container modules accommodated inside a single insulated housing. Detailed description of the invention according to a preferred embodiment

[0087] Fig. 1.A, Fig. 1.B and Fig. 1.C show container modules in accordance with possible embodiments. For each of them the system of reference coordinates of the predefined length L, predefined height H and predefined width W are shown. During the transport in step (I) the predefined length L is arranged substantially horizontally.

[0088] Each container module 2 comprises a frame 6 in the form of a right-angled parallelepiped, which circumscribes a storage compartment 4 for a liquid, preferably water.

[0089] The frame 6 delimits a smaller base 8 and a larger base 14. The smaller base 8 of the right-angled parallelepiped is arranged at right angles to the predefined length L. The larger base 14 is arranged at right angles to the smaller base 8.

[0090] During step (I), the container module 2 rests on the larger base 14.

[0091] At the end of step (II), the container modules 2 rests on the smaller base 8 owing to the rotation, and the predefined length extends vertically. In this connection see Fig. 2.

[0092] The storage compartment 4 may have a cross-section - orthogonal to the length L - which is polygonal (for example square or rectangular) or circular.

[0093] In the embodiment of Fig. 1.C, corner fittings 22 of the frame 6 for rotatable locking devices (so-called "twistlocks") - according to ISO standard 1161:2016 - of a container module 2 can be seen.

[0094] Fig. 2 shows a generic container module 2 rotated - at the end of step (III) - with respect to step (I), so that the predefined length L is oriented substantially vertically.

[0095] Fig. 3 and Fig. 4 show two storage systems 1 in accordance with different embodiments. Although these figures show, respectively, two and four container modules 2, this number is not limiting for the purposes of the present invention.

[0096] The container modules 2 in Fig. 3 are arranged alongside each other and spaced from each other (i.e. not in mutual contact).

[0097] The container modules 2 in Fig. 4 make mutual contact by means of side faces 30 and by means of respective longitudinal edges 28.

[0098] One or more mechanical connection(s) 20 join together the plurality of container modules 2 so as to provide a monolithic storage system 1. This / these mechanical connection(s) 20 is / are connected to the frames 2 and / or to the corner fittings 22 (when available).

[0099] Fig. 5.A and Fig. 6.A show two schematic illustrations of the fluid connections between container modules 4, which are respectively arranged in series or in parallel.

[0100] In the series connection - Fig. 5.A - the liquid supplied from a liquid source 10 is introduced into the first container module 2 in a vertically lower portion 18 of the storage compartment 4. The liquid is supplied by means of a distributor 32 located inside the storage compartment 4. A header 34 is located in a vertically upper portion 16 of the storage compartment 4 of the same container module 2 and conveys the liquid from the storage compartment 4 of the first container module 2 to the storage compartment 4 of the second container module 2 - in the direction of flow of the liquid - via a conveying line 36.

[0101] The liquid crosses the storage compartment 4 of the second container module 2 and of the following third container module 2 in the same way as described for the first container module 2.

[0102] In the fourth container module 2, the liquid entering into the storage compartment 4 through the distributor 32 flows out through the header 34. This outflowing liquid could be supplied to one or more successive container modules 2 or - according to the embodiment shown - is supplied to a liquid user 12 via a supply line 26.

[0103] In the parallel connection - Fig. 6.A - the liquid supplied from a liquid source 10 is introduced parallel into the container modules 2 in vertically lower portions 18 of each storage compartment 4. The broken lines extending to the left of the first module on the left indicate that there could more than four modules.

[0104] The liquid is supplied by means of distributors 32 in the same way as for the preceding embodiment. A header 34 is located in a vertically upper portion 16 of each storage compartment 4 and conveys the liquid from the storage compartment 4 of each container module 2 to the liquid user 12 via a supply line 26.

[0105] Fig. 5.B and Fig. 6.B show two schematic illustrations of the fluid connections between container modules 4, which are arranged respectively in series or in parallel, corresponding to Fig. 5.A and Fig. 6.A, but in which the direction of transit of the liquid is reversed.

[0106] In the series connection - Fig. 5.B - the liquid supplied from the liquid user 12 is introduced into the first container module 2 on the right (with reference to the schematic illustration) in a vertically upper portion 16 of the storage compartment 4. The liquid is supplied by means of a distributor 34 located inside the storage compartment 4. A header 32 is located in a vertically lower portion 18 of the storage compartment 4 of the same container module 2 and conveys the liquid from the storage compartment 4 of the first container module 2 to the storage compartment 4 of the second container module 2 - in the direction of flow of the liquid - via a conveying line 36.

[0107] The liquid crosses the storage compartment 4 of the second container module 2 and of the following third container module 2 in the same way as described for the first container module 2.

[0108] In the fourth container module 2, the liquid entering into the storage compartment 4 through the distributor 34 flows out through the header 32. This outflowing liquid is supplied to the liquid source 10 via the supply line 26.

[0109] In the parallel connection - Fig. 6.B - the liquid supplied from the liquid user 12 is introduced parallel into the container modules 2 in vertically upper portions 16 of each storage compartment 4. The broken lines extending to the left of the last module on the left indicate that there could more than four modules.

[0110] The liquid is supplied by means of distributors 34 in the same way as for the preceding embodiment. A header 32 is located in a vertically lower portion 18 of each storage compartment 4 and conveys the liquid from the storage compartment 4 of each container module 2 to the liquid source 10 via the filling line 24.

[0111] Fig. 7.A, Fig. 7.B, Fig. 8.A and Fig. 8.B show schematic illustrations of the fluid connections between container modules 4, in series or in parallel, in accordance with further embodiments.

[0112] These embodiments differ from the corresponding Fig. 5.A, Fig. 5.B and Fig. 6.A, Fig. 6.B, respectively, owing to the presence of at least one bypass line which is arranged so as to connect a point upstream and at least one point downstream of at least one container module 2. It is pointed out that the presence of one or more bypass lines necessarily involves the presence of valves and actuating devices which, for the sake of simpler description, are neither shown in the figures nor discussed in this description.

[0113] In particular, the embodiment of Fig. 7.A shows a first bypass line 38 which extends between a point downstream of the liquid source and upstream of the first container module 2 and which conveys the liquid into at least one point downstream of the first container module 2. By way of example, this downstream point could be arranged between the first and the second container modules and / or between the second and third container modules and / or between the third and fourth container modules and / or downstream of the fourth container module.

[0114] A second bypass line 40 places in fluid communication the storage compartments 4 of two container modules 2 separated by an intermediate container module, without the liquid passing through the storage compartment of said intermediate container module. In the example shown in Fig. 7, the intermediate container module is the second from the left, so that the liquid drawn off from the storage compartment 4 of the first container module on the left via the conveying line 36 is supplied downstream of the second container module without passing through the storage compartment of the second container module.

[0115] A third bypass line 42 places in fluid communication the storage compartment 4 of at least one container module 2 preceding a last container module 2 with the liquid user 12.

[0116] Considerations similar to those of Fig. 7A apply to the embodiment of Fig. 8.A, although the arrangement of the container modules is in parallel.

[0117] In the example shown in Fig. 8.A, the intermediate container module is the second one from the right, so that the liquid drawn downstream of the first container module (first from the right) is supplied downstream of the second container module.

[0118] Since it consists of a parallel arrangement, the bypass lines 40, 42 of Fig. 8.A are also arranged along the supply line 26.

[0119] The embodiments of Fig. 7.B and Fig. 8.B correspond to the embodiments Fig. 7.A and Fig. 8.A, but the direction of transit of the liquid is reversed.

[0120] Fig. 9.A and Fig. 10.A show two diagrams of a district heating plant in accordance with various embodiments in which the storage system is of pressurized type or the atmospheric (non-pressurized) type, respectively.

[0121] The heated liquid is produced in a heat generating station 44 which performs the function of a heat source 10. The heat generating station 44 and the storage system 1 are connected via the filling line 24. The storage system 1 is instead connected to one or more liquid users 12 via at least one supply line 26.

[0122] The heat generating station 44 and said one or more liquid users 12 are connected via at least one direct supply line 52, which does pass through (i.e. bypasses) the storage system 1.

[0123] Said one or more liquid users 12 and the heat generating station 44 are also connected via at least one return line 46 so as to form a circuit.

[0124] In this way, the liquid heated in the heat generating station 44 flows towards said liquid user(s) 12 via the storage system 1 and / or via the direct supply line 52. After said liquid has been at least partially cooled at said liquid user(s) 12, said at least partially cooled liquid returns to the heat generating station 44 via the return line 46.

[0125] Along the return line 46 there is arranged a first expansion tank 48, which receives the at least partially cooled liquid from said return line and which supplies said liquid to the heat generating station 44.

[0126] In the embodiment shown, at least one expansion tank 48' is arranged upstream of a point in which an additional line 54 - which connects the storage system 1 and the return line 1 - enters into the return line 46. Although the additional line 54 is shown as exiting from the first container module 2, said feature is not limiting in that the additional line 54 could be connected to any container module 2 different from the first module or in addition to the first module.

[0127] The diagram of Fig. 9.B differs from the diagram of Fig. 9.A at least in that the liquid may be conveyed from the storage system to the heat generating station 44 via the filling line 24, in that the liquid may be conveyed from the liquid user 12 to the storage system 1 via the supply line 26, and in that the liquid may be conveyed from the return line 46 to the storage system 1 via the additional line 54.

[0128] The diagram of Fig. 10.A differs from the diagram of Fig. 9.A at least because of the absence of expansion tanks and obviously because the storage system 1 is not pressurized.

[0129] The diagram of Fig. 10.B differs from the diagram of Fig. 10.A at least in that the liquid may be conveyed from the storage system to the heat generating station 44 via the filling line 24, in that the liquid may be conveyed from the liquid user 12 to the storage system 1 via the supply line 26, and in that the liquid may be conveyed from the return line 46 to the storage system 1 via the additional line 54.

[0130] Fig. 11 shows a top plan view of a storage system according to a possible embodiment.

[0131] Said figure clearly shows the presence of a single insulated housing 60 which accommodates a plurality of container modules 2.

[0132] This figure also clearly shows piping 62 which provide a fluid connection between pairs of adjacent container modules 2.

[0133] Even though not previously specified, a person skilled in the art may, drawing on the typical expertise in the sector, vary or replace some of the aspects indicated above with other technically equivalent elements.

[0134] These variation or replacements also fall within the scope of the following claims.

[0135] Moreover, any alternative illustrated in relation to a particular embodiment may be implemented independently of the other variants described.LIST OF REFERENCE NUMBERS

[0136] 1storage system 2container module 4storage compartment 6frame 8smaller base 10liquid source 12liquid user 14larger base 16vertically upper portion 18vertically lower portion 20mechanical connection 22corner fitting 24filling line 26supply line 28longitudinal edge 30side face 32distributor or header 34header or distributor 36conveying line 38(first) bypass line 40(second) bypass line 42(third) bypass line 44heat generating station 46return line 48expansion tank 50district heating plant 52direct supply line 54additional line 56first branch 58second branch 60insulated housing 62piping Hpredefined height Lpredefined length Wpredefined width

Examples

Embodiment Construction

[0087]Fig. 1.A, Fig. 1.B and Fig. 1.C show container modules in accordance with possible embodiments. For each of them the system of reference coordinates of the predefined length L, predefined height H and predefined width W are shown. During the transport in step (I) the predefined length L is arranged substantially horizontally.

[0088]Each container module 2 comprises a frame 6 in the form of a right-angled parallelepiped, which circumscribes a storage compartment 4 for a liquid, preferably water.

[0089]The frame 6 delimits a smaller base 8 and a larger base 14. The smaller base 8 of the right-angled parallelepiped is arranged at right angles to the predefined length L. The larger base 14 is arranged at right angles to the smaller base 8.

[0090]During step (I), the container module 2 rests on the larger base 14.

[0091]At the end of step (II), the container modules 2 rests on the smaller base 8 owing to the rotation, and the predefined length extends vertically. In this connection see...

Claims

1. A storage system (1) for a heated liquid, wherein said storage system (1) comprises a plurality of container modules (2) and wherein: - each container module (2) delimits a storage compartment (4) for a heated liquid; - each container module (2) has a predefined length (L), predefined height (H) and predefined width (W); - said plurality of container modules (2) is arranged in an adjacent or mutually contacting position; - the predefined length (L) of each container module (2) is oriented substantially vertically; - the storage compartments (4) of the container modules are connected together with a fluid connection; - optionally said storage system (1) comprises a filling line (24) for filling said storage system by means of a liquid source (10) and, preferably, a supply line (26) connecting said storage system to a liquid user (12); wherein at least one container module (2) or a plurality of said container modules (2) comprises: (a) at least one distributor or header (32) located in a vertically lower portion (18) of the storage compartment (4) for supplying the liquid to the container module (2) or for conveying the liquid outside of the storage compartment; and (b) at least one header or distributor (34) located in a vertically upper portion (16) of the storage compartment (4) for conveying the liquid outside of the storage compartment (4) or for supplying the liquid to the container module.

2. The storage system (1) according to the preceding claim, wherein said container modules (2) are connected together in series whereby the header (32; 34) of a container module (2) which is upstream in the direction of fluid flow is connected to the distributor (32; 34) of a container module which is downstream in the direction of fluid flow.

3. The storage system (1) according to the preceding claim, wherein the distributor (32; 34) of the first container module (2) of said series is connected to the liquid source (10) via the filling line (24) or to the liquid user (12) via a supply line (26), and the header (34; 32) of the last container module (2) of said series is connected to the liquid user (12) via the supply line (26) or to the liquid source (10) via the filling line (24).

4. The storage system (1) according to claim 1, wherein said container modules (2) are connected together in parallel, whereby all the distributors (32; 34) of the container modules (2) are connected to the liquid source (10) via the filling line (24) or to the liquid user (12) via the supply line (26), and all the headers (34; 32) of the container modules (2) are connected to the liquid user (12) via the supply line (26) or to the liquid source (10) via the filling line (24).

5. The storage system (1) according to any one of the preceding claims, comprising one or more bypass line(s) (38, 40, 42) arranged so as to connect a point upstream and at least one point downstream of at least one container module (2), so that the liquid does not pass through the storage compartment (4) of that container module (2); preferably said one or more bypass line(s) (38, 40, 42) being arranged so as to connect: - the liquid source (1) with the storage compartment (4) of at least one container module (2) following a first container module (2) or preceding a last container module (2); and / or - the storage compartments (4) of two container modules (2) separated by an intermediate module, without the liquid passing through the storage compartment of said intermediate container module; and / or - the liquid user (12) with the storage compartment (4) of at least one container module (2) preceding a last module (2) or following a first container module (2).

6. The storage system (1) according to any one of the preceding claims, wherein: said predefined length (L) is equal to or less than 13,500 mm, said predefined height (H) is equal to or less than 3000 mm, and said predefined width (W) is equal to or less than 3000 mm; or said predefined length (L), said predefined height (H) and said predefined width (W) are selected according to ISO standard 668:2020, wherein: - said predefined length (L) is selected from: 13,716 mm, 12,192 mm, 9125 mm, 6058 mm, or 2991 mm; and - said predefined height (H) is selected from: 1295 mm, 2438 mm, 2591 mm, or 2896 mm; and - said predefined width (W) is 2438 mm; preferably wherein: - said predefined length (L) is 6058 mm; and - said predefined height (H) is 2438 mm; and - said predefined width (W) is 2438 mm.

7. The storage system (1) according to any one of the preceding claims, comprising one or more mechanical connection(s) (20) between said plurality of container modules (2) so as to provide a monolithic storage system (1); wherein said mechanical connection(s) (20) is / are arranged between frames (6) or between corner fittings (22) for rotatable locking devices (twistlocks) - according to ISO standard 1161:2016 - of adjacent container modules (2).

8. A district heating plant (50) comprising: - the storage system (1) according to any one of the preceding claims; - a heat generating station (44) having the function of said liquid source (10) for the heated liquid; wherein the storage system (1) and the heat generating station (44) are connected via the filling line (24) and wherein the storage system (1) is connected to one or more liquid users (12) by means of at least one supply line (26); - at least one return line (46) which connects said one or more liquid users (12) to the heat generating station (44) so as to form a circuit.

9. A method for building the storage system (1) for a liquid according to any one of claims 1-7, wherein said method comprises the following steps: (I) transporting a plurality of container modules (2); wherein each container module (2) delimits a storage compartment (4) for a liquid; wherein each container module (2) has predefined length (L), predefined height (H), and predefined width (W); wherein, during step (I), the predefined length (L) is oriented substantially horizontally; (II) arranging said plurality of container modules (2) in an adjacent or mutually contacting position, wherein each container module (2) is rotated with respect to step (I) so that said predefined length (L) is oriented substantially vertically; (III) realizing a fluid connection between the storage compartments (4) of the container modules (2) of step (II) so as to provide said storage system (1); (IV) optionally filling the storage system (1) of step (III) by means of a liquid source (10) and, preferably, supplying a liquid user (12) via the filled storage system.

10. The method according to claim 9, wherein said predefined length (L) is equal to or less than 13,500 mm, said predefined height (H) is equal to or less than 3000 mm, and said predefined width (W) is equal to or less than 3000 mm; or said predefined length (L), said predefined height (H), and said predefined width (W) are selected according to ISO standard 668:2020, wherein: - said predefined length (L) is selected from: 13,716 mm, 12,192 mm, 9125 mm, 6058 mm, or2991 mm; and - said predefined height (H) is selected from: 1295 mm, 2438 mm, 2591 mm, or 2896 mm; and - said predefined width (W) is 2438 mm; preferably wherein: - said predefined length (L) is 6058 mm; and - said predefined height (H) is 2438 mm; and - said predefined width (W) is 2438 mm.

11. The method according to any one of claims 9 or 10, wherein the step (III) comprises a series or parallel connection.

12. The method according to claim 11, wherein said series or parallel connection comprises drawing off liquid from a vertically upper portion (16) of a storage compartment (4) of a preceding container module (2) and supplying the liquid thus drawn off to a vertically lower portion (18) of a storage compartment (4) of a following container module (2).

13. The method according to claim 11, wherein said series or parallel connection comprises drawing off the liquid from a vertically lower portion (18) of a storage compartment (4) of a preceding container module (2) and supplying the liquid thus drawn off to a vertically upper portion (16) of a storage compartment (4) of a following container module (2).

14. The method according to any one of claims 9-13, said method comprising: (V) realizing a mechanical connection (20) between the container modules (2) of step (II) so as to provide a monolithic storage system (1); wherein said mechanical connection (20) is arranged between frames (6) or between corner fittings (22) for rotatable locking devices (twistlocks) - according to ISO standard 1161:2016 - of adjacent container modules (2).

15. Use of the storage system (1) for a liquid according to any one of claims 1-7 as a thermal storage system, preferably as a thermal storage system of a district heating plant (50), more preferably wherein said liquid is a heated liquid - for example water - at a temperature of comprised from 70°C to 140°C.

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