Thermal storage chamber for heating and cooling by coupling between thermocline storage and MCP storage

Abstract

The invention relates to a thermal storage enclosure (100) for storing heat and cold by coupling thermocline storage with a phase-change material, characterized in that it comprises: a tank (80) defining an internal volume (V); a first (70) and a second (60) closure element; and a separation element (50) dividing the internal volume (V) into a first volume (V1) and a second volume (V2), wherein the first part (20) comprises a coil-type heat exchanger (21) in which a first heat transfer fluid is able to circulate, the second part (30) comprises a plurality of capsules (31) containing a phase-change material, and the first part (20) and the second part (30) respectively comprise first inlet and / or outlet means (71) and second inlet and / or outlet means (61) for a second heat transfer fluid. Figure 1

Description

Title of the invention: Thermal storage chamber for heat and cold by coupling between thermocline storage and PCM storage. TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to the general field of Thermal Storage Systems (TSS), in particular thermal storage systems by thermocline and / or by Phase Change Materials (PCM), and more specifically to such bi-functional storage systems allowing the storage of heat and cold alternately, in particular seasonally.

[0002] The invention finds its application in any type of hot and cold storage system, and can be implemented in any type of hot and cold networks, in particular for heating, including domestic hot water production, and cooling of buildings (air conditioning), in particular domestic, urban, rural or industrial.

[0003] The invention thus proposes a thermal storage enclosure for heat and cold by coupling between thermocline type storage and phase change material type storage, as well as a thermal storage process implemented by means of such a thermal storage enclosure. STATE OF THE ART

[0004] Thermocline-type thermal storage is a sensible heat storage system comprising a temperature gradient called a thermocline. Heat storage is achieved by injecting a hot heat transfer fluid into the upper part of a tank filled with a low-temperature storage material. The fluid transfers its heat to the solid, which gradually warms up. Within the storage system, a hot zone, a cold zone, and a thermal gradient separating them—this is the thermocline—appear. The gradient progresses along the tank until it reaches the outlet. The charging process then stops. During discharge, the low-temperature fluid is injected into the bottom of the tank, and the reverse process occurs. The material transfers its heat to the fluid, and the fluid warms up. The hot fluid can then be used for energy processes.

[0005] Thermal storage exploiting the latent heat of a phase change material (PCM) takes advantage of the PCM's ability to change from a solid to a liquid state (melting) under the influence of heat. The phase change energy is absorbed during the melting of the PCM and released during its solidification. The energy density of PCMs, expressed in kWh / m³, is higher than that of sensible heat storage systems, which gives latent heat storage systems greater compactness and lower heat losses.

[0006] Typically, a heat transfer fluid is used to transfer heat from the source to the storage unit. Since the PCM undergoes melting / solidification cycles, it cannot be used as a heat transfer fluid. Heat transfer technologies vary, such as the use of finned tube heat exchangers, multi-tube heat exchangers, or even the encapsulation of the PCM. Thus, when a hot fluid comes into indirect contact with the PCM, the latter changes from a solid to a liquid state (melting), absorbing heat from the fluid. Conversely, if the fluid is cold, the PCM releases its heat to the heat transfer fluid during its solidification.

[0007] The use of tube heat exchangers, particularly in the form of coaxial coils, is described for example in the article "A Review of Recent Passive Heat Transfer En-hancement Methods", SSM Ajarostaghi et al, MDPI, Energies 2022, 15, 986, 28 January 2022. Thus, a double helical coil heat exchanger is evaluated in an ice storage process. Other tube heat exchangers are described in the article "Performance evaluation of three latent heat storage designs for cogeneration applications," T. Xu et al., Solar Energy 225 (2021), 444-462, July 28, 2021; in the article "Development and validation of Nusselt number correlations for a helical coil-based energy storage integrated with a solar water heating system," S. Ayuob et al., Journal of Energy Storage, Volume 55, Part D, November 30, 2022; and in the article "Experimental investigations on the thermal performance of an ice storage system using twin concentric helical coils," HEAbdelrahman, Applied Thermal Engineering, Volume 179, October 2020. .

[0008] Moreover, the encapsulation of the MCP, in particular in tubular form, is described for example in the article "A review on macro-encapsulated phase change material for building envelope applications", Z. Liu et al, Building and Environment, Volume 144, pages 281-294, October 15, 2018.

[0009] Thermal storage solutions are already known in the prior art which allow either "hot" type storage for heating, or "cold" type storage for cooling.

[0010] However, there is a need to design a thermal storage system, both "hot" and "cold," that is as compact and simple as possible for its applications, and that can, in particular, meet alternating, especially seasonal, heating and cooling needs. Specifically, there is a need to optimize the means and methods of positioning the tubes of the tube-and-tube heat exchangers, on the one hand, and the PCM encapsulants, on the other, as well as the positioning of the tubes relative to the encapsulants. Description of the invention

[0011] The invention aims to remedy at least partially the aforementioned needs above and the disadvantages related to the achievements of prior art.

[0012] The invention thus relates, according to one of its aspects, to a thermal storage enclosure, in particular for the storage of heat and the storage of cold, in particular for alternating heat and cold, particularly seasonally, in particular between summer and winter, by coupling between thermocline-type storage and phase-change material-type storage, characterized in that it comprises:

[0013] - a tank, defining an internal volume, comprising a first end and a second end, opposite to the first end,

[0014] - a first closing element, located at the first end of the tank,

[0015] - a second closing element, located at the second end of the tank, the internal volume being delimited by the tank and the first and second closing elements,

[0016] - a separating element, located inside the tank, dividing the internal volume into a first volume and a second volume, and delimiting the thermal storage enclosure into a first part containing the first volume and a second part containing the second volume,

[0017] the first part comprising a coil-type heat exchanger in which a first heat transfer fluid is suitable for circulating, in particular for cold storage,

[0018] the second part comprising a plurality of capsules containing a phase-change material,

[0019] the first part comprising first inlet and / or outlet means for a second heat transfer fluid suitable for circulating in the first volume around the coil-type heat exchanger, and in the second volume around the capsules, in particular for cold storage and for heat storage, the separating element being configured to allow fluid communication of the second heat transfer fluid between the first part and the second part, the second heat transfer fluid acting in particular as a phase-change fluid for cold storage and as a heat transfer fluid for heat storage, and

[0020] the second part comprising second means of inlet and / or outlet of the second heat transfer fluid.

[0021] The thermal storage enclosure according to the invention may further comprise one or more of the following characteristics taken individually or in any possible technical combinations.

[0022] By "cold storage" and "heat storage", it is understood that the thermal energy stored as "cold" is less than the thermal energy stored as "heat", in particular less by at least 20°C, or even by at least 40°C, or even by minus 50°C, or even at least 100°C. In particular, cold storage can correspond to a temperature between -10°C and 15°C, and hot storage can correspond to a temperature between 35°C and 90°C.

[0023] Advantageously, the thermal storage enclosure extends vertically during use. In particular, the first and second closing elements are advantageously superimposed vertically relative to each other, corresponding respectively to the bottom and top of the thermal storage enclosure. Advantageously still, the second heat transfer fluid is water.

[0024] The solid / liquid phase change temperature of the phase change material can be between 25°C and 70°C, or even between 40°C and 70°C, or even between 50°C and 70°C.

[0025] The second heat transfer fluid may be a phase change fluid. In particular, the second heat transfer fluid may have a solid / liquid phase change temperature that may be between -5°C and 15°C, in particular on the order of 0°C.

[0026] Advantageously, the solid / liquid phase change temperature of the phase change material can be at least 10°C, or even at least 20°C, higher than the solid / liquid phase change temperature of the second heat transfer fluid.

[0027] Preferably, the tank can be in the form of a tubular tank, in particular of cylindrical shape, for example in the form of a tubular calender, in particular a cylindrical calender.

[0028] Preferably, the tank can be opened at its first end and / or its second end.

[0029] Furthermore, the first and / or second closing element may advantageously be in the form of a lid, in particular a lid that is removable from the tank. The first and / or second closing element may have a spherical shape, in particular a spherical shape flattened at its center. Alternatively, the first and / or second closing element may also have a flat shape. In addition, the first and / or second closing element may include a flange for attaching it to the tank, in particular a flange formed around its circumference, in particular around the circumference of a spherical shape, in particular a spherical shape flattened at its center, or a flat shape.The tank may also include a fixing flange at its first end and / or its second end, particularly around its perimeter, for fixing it to the first closing element and / or the second closing element.

[0030] The separating element may be in the form of a separating plate, particularly in the shape of a disc, for example a disc with a hole in its center. The element The separation element may thus include an annular plate. In particular, the separation element may be in the form of one or more bearing rings. The separation element may be fixed to the inner wall of the tank.

[0031] Furthermore, the coil-type heat exchanger may comprise a plurality of coils, in particular two coils, or even at least three coils.

[0032] The coils can advantageously be concentric. The coils can thus each have a helical shape extending along the central longitudinal axis of the thermal storage enclosure, the coils being centered with respect to the central longitudinal axis of the thermal storage enclosure.

[0033] Furthermore, the coils can advantageously be connected in series. Advantageously, the series connection of the coils can make it possible to obtain a flow velocity of the first heat transfer fluid circulating in the coils at the beginning of the turbulent regime so as to promote heat exchange.

[0034] In addition, each coil may include a tube, in particular a metallic tube, for example made of stainless steel, for example of type 316L or 304L stainless steel, surrounded by fin(s), in particular in the form of a spiral fin, in particular metallic, for example made of copper.

[0035] The coil-type heat exchanger may in particular include a coil comprising a central tube extending along the longitudinal central axis of the thermal storage enclosure for the inlet and / or outlet, in particular the inlet, of the first heat transfer fluid.

[0036] In addition, the coil-type heat exchanger may include a coil comprising a lateral tube extending along the longitudinal central axis of the thermal storage enclosure for the outlet and / or inlet, in particular the outlet, of the first heat transfer fluid, the lateral tube being in particular axially offset with respect to the central tube.

[0037] The first part may include a first support device for the coil-type heat exchanger configured to ensure spacing between each turn of the coil(s). Advantageously, the first support device may also be able to support long coil lengths.

[0038] In particular, the first support device may comprise at least one first longitudinal upright, in particular of substantially rectangular cross-section, in particular at least two first longitudinal uprights, or even at least three first longitudinal uprights, in particular for each coil of the heat exchanger, extending in particular along the longitudinal axis of the thermal storage enclosure, in particular between the first closing element and the separating element, provided with one or more retaining tabs for the coil(s), in particular retaining tabs arranged regularly along said coil(s). at least one first longitudinal support, notably in the form of hooks surrounding at least partially the coils.

[0039] Advantageously, the first longitudinal upright(s) may have a sufficiently thin thickness, for example between 3.5 mm and 4.5 mm, in particular on the order of 4 mm.

[0040] In addition, at least one first longitudinal member, in particular each first longitudinal member, may have a fixing hole, in particular a hole, for holding the coil-type heat exchanger in position relative to the separation element, in particular for fixing to one or more bearing rings of the separation element.

[0041] Furthermore, the capsules may be in the form of tubes, particularly cylindrical tubes. Alternatively, the capsules may also be in the form of spheres or pellets, or even plates. The capsules may be distributed over several stacked levels along the longitudinal central axis of the thermal storage enclosure. Each level may comprise a plurality of capsules, in particular at least 6, or even at least 8, or even at least 10. The capsules may extend substantially parallel to one another in a direction substantially perpendicular to the longitudinal central axis of the thermal storage enclosure. Advantageously, the capsules may extend horizontally relative to the vertical longitudinal central axis of the thermal storage enclosure so as to prevent any segregation of the phase-change material located inside the capsules.

[0042] In particular, two adjacent floors may have capsules that extend in a crisscross pattern with respect to each other. The capsules of a first floor may, in particular, extend substantially perpendicularly with respect to the capsules of a second floor adjacent to the first floor.

[0043] Furthermore, the volume of the capsules can be partially filled by the phase change material, the capsules being in particular filled to 95% or less of their volume.

[0044] The second part may comprise at least 5, or even at least 7, or even at least 9, levels of capsules.

[0045] Preferably, the phase-change material of the capsules may comprise sodium acetate trihydrate.

[0046] Furthermore, the second part may include a second capsule support device configured to ensure spacing between the capsules and allow circulation of the second heat transfer fluid. Advantageously, the second support device is configured to allow positioning and retention of the capsules.

[0047] Furthermore, the first closing element may include the first means of inlet and / or outlet, in particular in the form of a first distributor, of the second heat transfer fluid.

[0048] In particular, the coil-type heat exchanger may include a coil comprising a central tube extending along the longitudinal central axis of the thermal storage vessel for the inlet and / or outlet, particularly the inlet, of the first heat transfer fluid. The first inlet and / or outlet means may include a first tubular opening into which the central tube opens, having a cross-section smaller than the cross-section of the first tubular opening. The second heat transfer fluid may be able to circulate between the inner wall of the tubular opening and the outer wall of the central tube.

[0049] Furthermore, the first closure element may include a first deflector plate inside the first volume, located at the first inlet and / or outlet means, attached to the inner wall of the first closure element, notably by means of fixing studs, in particular at least two, or even at least three, or even at least four, allowing spacing between the first deflector plate and the inner wall of the first closure element. Advantageously, the presence of the first deflector plate can limit the jet effect and ensure homogenization of the circulation of the second heat transfer fluid in the first volume.

[0050] In addition, the second closing element may include the second inlet and / or outlet means, in particular in the form of a second distributor, of the second heat transfer fluid.

[0051] The second inlet and / or outlet means may include a second tubular opening, in particular in the form of a tube extending from the outer wall of the second closure element, in particular from the center of this outer wall, for the circulation of the second heat transfer fluid.

[0052] Furthermore, the second closure element may include a second deflector plate inside the second volume, aligned with the second inlet and / or outlet means, attached in particular to the inner wall of the second closure element, notably by means of fixing studs, in particular at least two, or even at least three, or even at least four, allowing spacing between the second deflector plate and the inner wall of the second closure element. Advantageously, the presence of the second deflector plate can limit the jet effect and ensure homogenization of the circulation of the second heat transfer fluid in the second volume.

[0053] The first and second deflector plates may or may not be identical. Preferably, they have the same shape, in particular a disc shape. The first The deflector plate is typically in the form of a disc with a central opening allowing the passage of the central tube. The second deflector plate is typically in the form of a solid disc.

[0054] Furthermore, the invention also relates, according to another aspect, to a thermal storage method implemented by means of a thermal storage enclosure as defined above, characterized in that it comprises:

[0055] - the cold storage step by circulating the first heat transfer fluid in The coil-type heat exchanger results in latent energy storage through at least partial liquid / solid phase change of the second heat transfer fluid contained in the first volume, and sensible energy storage of the thermocline type through a temperature decrease of the second heat transfer fluid contained in the internal volume.

[0056] and / or,

[0057] - the heat storage step by circulation of the second heat transfer fluid, particularly between the second closing element and the first closing element, resulting in latent energy storage by solid / liquid phase change of the phase change material contained in the capsules and sensible energy storage of the thermocline type by a temperature increase of the phase change material and of the second heat transfer fluid contained in the internal volume. BRIEF DESCRIPTION OF THE FIGURES

[0058] Other advantages, purposes and special features of the invention will become apparent from the following non-limiting description of at least one embodiment of the present invention, with reference to the accompanying figures, in which: • Figure [1] represents, in a perspective front view with the interior of the tank visible, an example of a thermal storage enclosure according to the invention, • [Fig. 2] is a top view of the thermal storage enclosure of the [Fig. 1], with the interior of the tank made visible, • Figure [Fig. 3] is a view from below the thermal storage enclosure of Figure [Fig. 1], with the interior of the tank visible. • [Fig. 4] is a front view, both in vertical section and in perspective of the thermal storage enclosure of [Fig. 1], allowing visualization of the interior of the tank, • Fig. 5 represents, in a perspective front view, the coil-type heat exchanger of the thermal storage enclosure of Fig. 1. • [Fig.6] is a top view of the heat exchanger of [Fig.5], • [Fig.7] is a view from below of the heat exchanger of [Fig.5], • Figure 8 represents, partially and in perspective, an example of a serpentine with a spiral fin of a coil-type heat exchanger of a thermal storage enclosure according to the invention, • [Fig.9] represents, in perspective view, the capsules contained in the second volume of the second part of the thermal storage enclosure of [Fig.1], • [Fig. 10] is a top view of the capsules in [Fig. 9], • [Fig. 11] is a view from below the capsules of [Fig. 9], • Figure 12 is an enlarged partial cross-sectional view of the lower part of the first part of the thermal storage enclosure of the [Fig.1], • [Fig. 13] is an enlarged partial perspective view of the lower part of the first part of the thermal storage enclosure of [Fig. 1], • [Fig. 14] is an enlarged partial cross-sectional view of the upper part of the second section of the thermal storage enclosure of [Fig. 1], and • [Fig. 15] is an enlarged partial perspective view of the upper part of the second part of the thermal storage enclosure of [Fig. 1].

[0059] Throughout these figures, identical references may designate identical or analogous elements.

[0060] Furthermore, the different parts shown in the figures are not necessarily to a uniform scale, in order to make the figures more legible. DETAILED DESCRIPTION OF THE INVENTION

[0061] Throughout the description, given by way of non-limiting example, it is noted that the terms "vertical" and "horizontal" are defined with respect to the longitudinal central axis of the thermal storage enclosure. They relate in particular to an advantageous use of the thermal storage enclosure along a vertical extent.

[0062] In addition, it should be noted that the characteristics described below for the thermal storage enclosure 100 can be considered separately or according to any technically possible combination.

[0063] With reference to Figures 1 to 15, we will describe an example of a thermal storage enclosure 100 allowing the storage of heat and cold through the use of PCM storage and thermocline storage. In particular, the thermal storage enclosure 100 can allow the alternative storage, as needed, of "hot" energy in capsules 31 and in the second heat transfer fluid 23 present in the tank 80 in the form of a thermocline, and of "cold" energy in solid form, notably as ice, around a heat exchanger of the type Coil 21. Storage can thus be carried out alternately and seasonally, for example for residential applications. Advantageously, the same amount of heating and cooling energy can be stored.

[0064] Thus, as can be seen in particular in Figures 1 and 4, the thermal storage enclosure 100 first comprises a tank 80 which defines an internal volume V. The tank 80 has a first end 80i and a second end 80s, opposite the first end 80i. It extends vertically along a central longitudinal axis X.

[0065] The tank 80 can be in the form of a cylindrical tubular shell open at each end after unbolting, the tank 80 including in particular a first fixing flange 80ib at its first end 80i and a second fixing flange 80sb at its second end 80s, respectively for the fixing of the first 70 and second 60 closing elements, visible in figures 2 and 3. This possibility of access to the inside of the tank 80 makes it possible in particular to facilitate maintenance for the first 20 and second 30 parts defined later.

[0066] The first closing element 70 is located at the first end 80i of the tank 80 and the second closing element 60 is located at the second end 80s of the tank 80. They are in the form of a flattened cap in its center with a fixing flange 60b, 70b formed on their periphery.

[0067] It should be noted that the thermal storage enclosure 100 may include a sealing gasket between the tank 80 and the first closing element 70 and / or a sealing gasket between the tank 80 and the second closing element 60, in particular a sealing gasket made of polytetrafluoroethene (PTFE).

[0068] Furthermore, a separation element 50 is provided inside the tank 80. It divides the internal volume V into a first volume VI and a second volume V2 and delimits the thermal storage enclosure 100 into a first part 20 containing the first volume VI and a second part 30 containing the second volume V2. The separation element 50 is in the form of a separating plate, in particular in the form of a ring fixed to the inner wall of the tank 80.

[0069] The external diameter of the support element 50 can, for example, be between 550 mm and 600 mm, and the internal diameter of the support element 50 can, for example, be between 350 mm and 400 mm.

[0070] Furthermore, the first part 20 comprises a coil-type heat exchanger 21, more clearly visible in Figures 5 to 7, in which a first heat transfer fluid 24 circulates and the second part 30 comprises a plurality of capsules 31, more clearly visible in Figures 9 to 11, containing a phase change material 33.

[0071] As can be seen in [Fig. 4], the first part 20 may, for example, have a height H2o, measured along the longitudinal central axis X, of between 1000 mm and 1100 mm. The second part 30 may, for example, have a height H30, measured along the longitudinal central axis X, of between 500 mm and 600 mm. Furthermore, the width L80 of the tank 80, without the presence of the fixing flange 80sb, may be between 550 mm and 650 mm.

[0072] Furthermore, the first part 20 includes first inlet and / or outlet means 71, more clearly visible in Figures 12 and 13, for a second heat transfer fluid 23 suitable for circulating in the first volume VI around the coil-type heat exchanger 21, and in the second volume V2 around the capsules 31. Advantageously, the separating element 50 allows fluidic communication of the second heat transfer fluid 23 between the first part 20 and the second part 30. In addition, the second part 30 includes second inlet and / or outlet means 61, more clearly visible in Figures 14 and 15, for the second heat transfer fluid 23. It should be noted that the second heat transfer fluid 23 acts as a heat transfer fluid in the context of heat storage, but it also acts as both a heat transfer fluid and a phase change material (PCM) storage fluid in the cold storage framework, as described below.

[0073] Consequently, two fluidic circuits, represented by means of arrows on [Fig.4], are present in the thermal storage enclosure 100 according to the invention.

[0074] A first fluidic circuit is located inside the tank 80 and outside the coil-type heat exchanger 21 and includes the second heat transfer fluid 23 which can change from liquid / solid phase.

[0075] Advantageously, the second heat transfer fluid 23 is water. Ice is then generated around the coil-type heat exchanger 21. The melting point of the second heat transfer fluid 23 is then approximately 0°C.

[0076] A second fluid circuit is located inside the coils of the coil-type heat exchanger 21. It includes the first heat transfer fluid 24, which remains liquid. The first heat transfer fluid 24 is advantageously an aqueous solution of monoethylene glycol (MEG), in particular a 30% MEG solution. Alternatively, it could also be a refrigerant, for example, of the R513A type.

[0077] Advantageously, the coil-type heat exchanger 21 comprises a plurality of coils, for example 2 or 3 coils, which are concentric and connected in series, and have fins. The series arrangement of the coils can make it possible to obtain a flow velocity of the first heat transfer fluid 24 circulating in the coils at the beginning of the turbulent regime so as to promote heat exchange.

[0078] Thus, as can be seen in figures 4 and 8, each coil can comprise a metallic tube 25, for example made of stainless steel of type 316L or 304L, surrounded by spiral metallic fins 26, for example made of copper.

[0079] The metal tube 25 may, for example, have an outside diameter of between 15 mm and 25 mm, for example between 20 mm and 22 mm. It can also have a thickness between 2 mm and 3 mm, for example around 2.5 mm.

[0080] The fins 26 may have a height, measured along the longitudinal central axis X, of between 10 mm and 20 mm, for example, approximately 15 mm. Their thickness may be between 0.3 mm and 1.5 mm, for example, approximately 1 mm. The pitch between the fins may be between 3.5 mm and 6.5 mm, for example, approximately 5 mm.

[0081] As shown in [Fig. 4], the spacing Es between two adjacent turns of a coil, measured along the longitudinal central axis X, can be between 85 mm and 95 mm, for example between 90 mm and 92 mm. Furthermore, the diameter Ds of a coil, measured perpendicular to the longitudinal central axis X, can, for example, be between 250 mm and 500 mm.

[0082] Furthermore, as seen in [Fig.4], the coil-type heat exchanger 21 comprises a coil including a central tube 25c extending along the longitudinal central axis X of the thermal storage enclosure 100 for the inlet and / or outlet of the first heat transfer fluid 24. The construction of the coils allows for the mechanization of a significant number of manufacturing steps, including the assembly of the tubes 25 by welding, the addition of the fins 26 around the tubes 25 and the shaping of the coil with a predefined pitch.

[0083] Furthermore, the coil-type heat exchanger 21 includes a coil comprising a lateral tube 72 extending along the longitudinal central axis X of the thermal storage enclosure 100 for the outlet and / or inlet of the first heat transfer fluid 24. The lateral tube 72 is axially offset with respect to the central tube 25c.

[0084] Furthermore, as can be seen in particular in [Fig.5], the first part 20 includes a first support device 22 for the coil-type heat exchanger 21. This makes it possible to guarantee a spacing between each turn of the coils and to support large lengths of the tubes 25 of the coils.

[0085] This first support device 22 comprises a plurality of first longitudinal uprights 27, of substantially rectangular cross-section, extending along the longitudinal central axis X of the thermal storage enclosure 100, between the first closure element 70 and the separation element 50.

[0086] These first longitudinal uprights 27 are provided with retaining lugs 29 for the coils of the serpentines, which are arranged regularly along each first longitudinal upright 27. These retaining lugs 29 are in the form of hooks partially surrounding the coils.

[0087] As can be seen in [Fig. 4], these longitudinal uprights 27 can, for example, have a thickness e27 of between 3.5 mm and 4.5 mm, in particular on the order of 4 mm.

[0088] In addition, the first longitudinal uprights 27 each have a fixing hole 28 in the form of a hole located at the upper end or top of the first longitudinal upright 27 so as to maintain the coil-type heat exchanger 21 in position relative to the separation element 50 by allowing the first longitudinal uprights 27 to be fixed to the separation element 50.

[0089] As can be seen in figures 9 to 11, the capsules 31 are in the form of cylindrical tubes, although this form is not limiting, distributed over several stages El, E2 superimposed on each other along the longitudinal central axis X of the thermal storage enclosure 100.

[0090] The capsules 31 are, for example, filled to 95% of their volume. The phase-change material 33, located in the capsules 31, can, for example, be sodium acetate trihydrate (or "Sodium Acetate Trihydrate" (SAT) in English).

[0091] The capsules 31 can have different lengths in order to occupy the space of the second volume V2, for example lengths between 220 mm and 550 mm. Their internal diameter can be between 35 mm and 40 mm. Their external diameter can be between 40 mm and 45 mm.

[0092] Advantageously, the capsules 31 extend horizontally with respect to the vertical longitudinal central axis X of the thermal storage enclosure 100 so as to prevent segregation of the phase change material 33 located inside the capsules 31. The preferred use of tubes for the capsules 31 facilitates their manufacture and allows resistance to the expansion of the phase change material 33.

[0093] Each stage El, E2 of capsules 31 comprises a plurality of capsules extending substantially parallel to one another in a direction substantially perpendicular to the longitudinal central axis X of the thermal storage enclosure 100. Moreover, as can be seen in [Fig. 9], two adjacent stages El, E2 comprise capsules 31 that extend in a crisscross pattern with respect to one another. In particular, the capsules of a first stage El extend substantially perpendicularly with respect to the capsules of a second stage E2 adjacent to the first stage El

[0094] The horizontality of the capsules 31 also allows the circulation of the second heat transfer fluid 23 from the first volume VI, around the capsules 31 while generating turbulence due to the crossings between capsules 31 to promote heat exchange.

[0095] Furthermore, the second part 30 comprises a second support device 32 for the capsules 31 configured to ensure spacing between the capsules 31 and to allow the circulation of the second heat transfer fluid 23 and the positioning and the maintaining the position of the capsules 31.

[0096] The second support device 32 comprises a plurality of second longitudinal uprights 36, of circular cross-section, which extend mainly around the perimeter of the second volume V2, along the longitudinal central axis X of the thermal storage enclosure 100, between the second closing element 60 and the separating element 50.

[0097] The second support device 22 therefore allows the positioning of each capsule 31 in parallel on each floor while leaving a space between each of them and allowing the crossing of the capsules 31 from one floor to the other.

[0098] The second longitudinal uprights 36 can be in the form of vertical rods with a diameter between 8 mm and 12 mm, for example of the order of 10 mm.

[0099] Furthermore, as can be seen in Figures 12 and 13, the first closing element 70 includes the first inlet and / or outlet means 71 in the form of a first distributor of the second heat transfer fluid 23.

[0100] Specifically, these first inlet and / or outlet means 71 comprise a first tubular opening 73 into which the central tube 25c opens, having a cross-section smaller than the cross-section of the first tubular opening 73. The second heat transfer fluid 23 is then able to circulate between the inner wall of the tubular opening 73 and the outer wall of the central tube 25c, as schematically shown by means of the arrows representing the second heat transfer fluid 23. Thus, a double concentric tube is formed for the passage of the second heat transfer fluid 23 and the passage of the first heat transfer fluid 24.

[0101] Advantageously, a first deflector plate 75 is located inside the first volume VI, opposite the first inlet and / or outlet means 71, and fixed to the first closure element 70 by means of studs 75p, here four studs 75p, allowing spacing for the circulation of the second heat transfer fluid 23. The presence of the first deflector plate 75 can limit the jet effect and ensure homogenization of the circulation of the second heat transfer fluid 23 in the first volume VL

[0102] Furthermore, as can be seen in Figures 14 and 15, the second closing element 60 includes the second inlet and / or outlet means 61 in the form of a second distributor of the second heat transfer fluid 23. These second inlet and / or outlet means 61 include a second tubular opening 62 for the circulation of the second heat transfer fluid 23.

[0103] A second deflector plate 65 is located inside the second volume V2 opposite the second inlet and / or outlet means 61, and fixed to the second closure element 60 by means of studs 65p, here four studs 65p, allowing an es space for the circulation of the second heat transfer fluid 23. The presence of the second deflector plate 65 can also here limit the jet effect and ensure homogenization of the circulation of the second heat transfer fluid 23 in the second volume V2.

[0104] The first deflector plate 75 and the second deflector plate 65 advantageously contribute to the generation of the thermocline during heat storage, in winter mode.

[0105] It should be noted that the tank 80, the capsules 31, the first support device 22, the second support device 32, the first closing element 70, the second closing element 60, the first deflector plate 75 and / or the second deflector plate 65 can be metallic, in particular being made of stainless steel, for example of type 316L or 204L stainless steel.

[0106] The thermal storage enclosure 100 according to the invention can take advantage of the phase change of two PCM-type materials, namely the second heat transfer fluid 23, preferably water, and the phase change material 33, preferably SAT, which has a melting point around 58°C. It also allows this PCM-type storage to be coupled to a thermocline-type coupling.

[0107] When implementing a thermal storage process using the thermal storage enclosure 100 according to the invention, it is possible to have first of all a cold storage stage, in particular in summer mode, in the form of latent energy by the freezing of the second heat transfer fluid 23 and in the form of sensible energy of the thermocline type by the decrease in the temperature of the total volume of the second heat transfer fluid 23.

[0108] In particular, during the thermal charging of the storage tank, the first heat transfer fluid 24 circulates in the coil-type heat exchanger 21, from the central tube 25c to the lateral tube 72, with a temperature of the first heat transfer fluid 24, for example, between -10°C and 0°C, or even between -10°C and -5°C. A heat exchange then occurs between the first heat transfer fluid 24 and the second heat transfer fluid 23 contained in the first volume V1, which causes the latter to freeze around the tubes of the coil-type heat exchanger 21 and also lowers the temperature of the second heat transfer fluid 23. The freezing is partial, meaning that ice is generated up to a certain distance from the fins 26, for example, up to 2 cm, for mechanical reasons and to facilitate heat discharge.

[0109] During the thermal discharge of the storage tank, a direct circulation of the second heat transfer fluid 23, here water, is forced between the second closing element 60 (water injection, for example at a temperature of around 15°C) and the first closing element 70 (water withdrawal, for example at a temperature of around 0°C to 5°C), the melting of the ice then releasing the latent heat.

[0110] It is also possible to have a heat storage stage, particularly in summer mode, in the form of latent energy by the melting of the encapsulated PCM 33 and predominantly in the form of sensible energy of the thermocline type by the increase in the temperature of the PCM 33 and the total volume of the second heat transfer fluid 23.

[0111] In particular, during the thermal charging of the storage, a direct circulation of the second heat transfer fluid 23 is forced between the second closing element 60 (injection of hot water, for example at a temperature between 70°C and 90°C) and the first closing element 70 (withdrawal of water).

[0112] During the thermal discharge of the storage, a direct circulation of the second heat transfer fluid 23 is forced between the first closing element 70 (injection of water, for example at a temperature of around 35°C) and the second closing element 60 (withdrawal of water, for example at a temperature between 55°C and 60°C).

[0113] Thus, the thermal storage unit 100 according to the invention can easily meet seasonal needs related to heat and cold storage. In winter, for example, heat can be stored at night and released during the day as needed. In summer, for example, cold can be stored at night and released during the day as needed. The thermal storage unit 100 therefore makes it possible to store heat in winter and cold in summer with a single storage tank instead of two, resulting in savings in terms of space and cost.

[0114] The solid / liquid phase change temperature of the second heat transfer fluid 23 can advantageously be between -5°C and 15°C. In particular, it is around 0°C when it is water.

[0115] The solid / liquid phase change temperature of the phase change material 33 can advantageously be between 25°C and 70°C.

[0116] Advantageously, the solid / liquid phase change temperature of the phase change material 33 is at least 10°C, or even at least 20°C, higher than the solid / liquid phase change temperature of the second heat transfer fluid 23.

[0117] Thanks to the invention, the use of the same tank 80 for both heat and cold storage makes it possible to obtain a highly compact, low-cost thermal storage unit suitable for multiple applications. It is thus possible to combine cold storage, notably through ice generation around the coil-type heat exchanger 21, with a thermocline around the tubes for heat storage, which is re-equilibrated with the capsules 31 containing the MCP 33.

[0118] The thermal discharge for cooling can be done directly by cir Water circulation is used to melt the ice without the need for an intermediate heat exchanger, thus increasing compactness. The water circulates between the ice-covered coils.

[0119] The thermal storage enclosure 100 can provide a thermal energy capacity of at least 9 kWh, particularly in summer mode or winter mode.

[0120] Table 1 below gives examples of operating ranges for the summer and winter operating modes envisaged for the thermal storage enclosure 100: Fluid Type [Min. inlet temperature; Max. inlet temperature] Circuit Nominal storage temperature [Min. temperature; Max. temperature] Storage Max. circuit pressure [Nomin. flow rate / Max. flow rate] Summer mode Fluid 24: MEG 30% [-10°C; -5°C] 0°C [-10°C; 15°C] < 10 bar [0.1 kg / s; 0.4 kg / s] Fluid 23: Water [0°C; 15°C] [0.1 kg / s; 0.5 kg / s] Winter mode Fluid 24: MEG 30% / 55°C-60°C [35°C; 90°C] < 10 bar / Fluid 23: Water [35°C; 90°C] [0.1 kg / s; 0.5 kg / s] Table 1

[0121] Of course, the invention is not limited to the embodiments just described. Various modifications can be made to them by a person skilled in the art.

[0122] In particular, the first part 20 could include means for heating the second heat transfer fluid 23, for example an electric resistance, for example with a power of the order of 3 kW.

Claims

Demands

1. Thermal storage enclosure (100), for (heat storage and cold storage, by coupling between thermocline-type storage and phase-change material-type storage, characterized in that it comprises: - a tank (80), defining an internal volume (V), comprising a first end (80i) and a second end (80s), opposite the first end (80i), - a first closing element (70), located at the first end (80i) of the tank (80), - a second closing element (60), located at the second end (80s) of the tank (80), the internal volume (V) being delimited by the tank (80) and the first (70) and second (60) closing elements, - a separating element (50), located inside the tank (80), dividing the internal volume (V) into a first volume (VI) and a second volume (V2), and delimiting the thermal storage enclosure (100) into a first part (20) containing the first volume (VI) and a second part (30) containing the second volume (V2), the first part (20) comprising a coil-type heat exchanger (21) in which a first heat transfer fluid (24) is suitable for circulating for cold storage, the second part (30) comprising a plurality of capsules (31) containing a phase-change material (33), the first part (20) comprising first inlet and / or outlet means (71) for a second heat transfer fluid (23) suitable for circulating in the first volume (VI) around the coil-type heat exchanger (21), and in the second volume (V2) around the capsules (31) for cold storage and for the heat storage,the separating element (50) being configured to allow fluidic communication of the second heat transfer fluid (23) between the first part (20) and the second part (30), the second heat transfer fluid (23) acting as a phase-change fluid for cold storage and as a heat transfer fluid for heat storage, and the second part (30) comprising second inlet and / or outlet means (61) for the second heat transfer fluid (23).

2. Thermal storage chamber according to claim 1, in which The coil-type heat exchanger (21) comprises a plurality of concentric coils and / or coils connected in series.

3. Thermal storage enclosure according to claim 1 or 2, wherein the coil-type heat exchanger (21) comprises a coil including a central tube (25c) extending along the longitudinal central axis (X) of the thermal storage enclosure (100) for the inlet and / or outlet of the first heat transfer fluid (24).

4. Thermal storage enclosure according to any one of the preceding claims, wherein the coil-type heat exchanger (21) comprises a coil including a side tube (72) extending along the longitudinal central axis (X) of the thermal storage enclosure (100) for the outlet and / or inlet of the first heat transfer fluid (24), the side tube (72) being in particular axially offset relative to the central tube (25c).

5. Thermal storage enclosure according to any one of the preceding claims, wherein the first part (20) comprises a first support device (22) for the coil-type heat exchanger (21) configured to ensure spacing between each turn of the coil(s).

6. Thermal storage enclosure according to claim 5, wherein the first support device (21) comprises at least one first longitudinal upright (27) provided with one or more retaining tabs (29) for the coils of the coil(s).

7. Thermal storage enclosure according to claim 6, wherein at least a first longitudinal upright (27) has a fixing hole (28) for holding the coil-type heat exchanger (21) in position relative to the separating element (50).

8. Thermal storage enclosure according to any one of the preceding claims, in which the capsules (31) are in the form of tubes, distributed over several stages (El, E2) superimposed one on the other along the longitudinal central axis (X) of the thermal storage enclosure (100), each stage (El, E2) comprising a plurality of capsules (31) extending substantially parallel to one another along a direction substantially perpendicular to the longitudinal central axis (X) of the thermal storage enclosure (100).

9. Thermal storage chamber according to claim 8, wherein two adjacent stages (E1, E2) comprise capsules (31) that extend in a crisscross pattern relative to each other, the capsules of a first floor (El) extending notably substantially perpendicularly in relation to the capsules of a second floor (E2) adjacent to the first floor (El).

10. Thermal storage chamber according to any one of the preceding claims, wherein the second part (30) comprises a second support device (32) for the capsules (31) configured to ensure spacing between the capsules (31) and to allow circulation of the second heat transfer fluid (23), comprising in particular at least one second longitudinal support (36).

11. Thermal storage enclosure according to any one of the preceding claims, wherein the first closure element (70) comprises the first inlet and / or outlet means (71) of the second heat transfer fluid (23), the coil-type heat exchanger (21) comprising a coil including a central tube (25c) extending along the longitudinal central axis (X) of the thermal storage enclosure (100) for the inlet and / or outlet of the first heat transfer fluid (24), the first inlet and / or outlet means (71) comprising a first tubular opening (73) into which the central tube (25c) opens, having a cross-section smaller than the cross-section of the first tubular opening (73), the second heat transfer fluid (23) being able to circulate between the inner wall of the tubular opening (73) and the outer wall of the central tube (25c).

12. Thermal storage enclosure according to claim 11, wherein the first closure element (70) comprises a first deflecting plate (75) inside the first volume (VI) at the right of the first inlet and / or outlet means (71).

13. Thermal storage enclosure according to any one of the preceding claims, wherein the second closure element (60) comprises the second inlet and / or outlet means (61) of the second heat transfer fluid (23), the second inlet and / or outlet means (61) comprising a second tubular opening (62) for the circulation of the second heat transfer fluid (23).

14. Thermal storage enclosure according to claim 13, wherein the second closing element (60) comprises a second deflector plate (65) inside the second volume (V2) at the level of the second inlet and / or outlet means (61).

15. A thermal storage method implemented by means of a thermal storage enclosure (100) according to any one of the claims previous ones, characterized in that it comprises: - the cold storage stage by circulation of the first heat transfer fluid (24) in the coil-type heat exchanger (21) resulting in latent energy storage by liquid / solid phase change, at least partial, of the second heat transfer fluid (23) contained in the first volume (VI) and sensible energy storage of the thermocline type by a temperature decrease of the second heat transfer fluid (23) contained in the internal volume (V), and / or, - the heat storage step by circulation of the second heat transfer fluid (23), in particular between the second closure element (60) and the first closure element (70), resulting in latent energy storage by solid / liquid phase change of the phase change material (33) contained in the capsules (31) and sensible energy storage of the thermocline type by an increase in temperature of the phase change material (33) and of the second heat transfer fluid (23) contained in the internal volume (V).