LASTOCALORIC DEVICE AND CORRESPONDING METHOD FOR MANUFACTURING SUCH A DEVICE

Description

[0001] The invention relates to an elastocaloric device for heat exchange, i.e., for the absorption and release of heat energy, by using an elastocaloric material. The invention further relates to a method for manufacturing such an elastocaloric device.

[0002] Traditionally, one or more such elastocaloric devices are installed or integrated into an elastocaloric machine. These devices utilize elastocaloric materials, also known as shape memory alloys (SMAs). With these pseudoelastic alloys, a significant deformation can be induced by the application of heat from a heat source. Upon removal of the heat source, the metal returns to its original shape. This effect is completely reversible. The reverse effect, the so-called elastocaloric effect, is also utilized. Through a deformation of the elastocaloric material, heat of transformation is exchanged with the surroundings, allowing the elastocaloric material to assume a lower energy state after the heat exchange.

[0003] Specifically, the elastocaloric material is subjected to mechanical stress, causing a crystalline phase transformation and resulting in heating. This heat is then dissipated, for example, via a heat sink, allowing the material to cool back to its initial temperature. When the mechanical stress is removed, i.e., the material relaxes, the order decreases and the material cools down to a temperature below its initial value, enabling it to absorb thermal energy from the surroundings. Through cyclical loading and unloading of the elastocaloric material, a corresponding heat input and output can thus be achieved, functioning as an elastocaloric heat pump.

[0004] By appropriately controlling the cyclic loading and unloading or relaxation, combined with appropriate control of a fluid circuit, which may contain a coolant such as water, a heat pump or chiller can be realized.

[0005] The introduction of mechanical forces onto the elastocaloric material is conventionally achieved via a clamping device, through which tensile forces of up to 1000 MPa can be applied.

[0006] In Fig. 1 An example of a clamping device 100 known from the state of the art is shown in perspective view.

[0007] In the depicted case, a roll 120 is wrapped with an element or wire 110 made of elastocaloric material. The roll 120 has clamping sections 121 at its ends, which allow the roll 120 to be clamped and loaded. By applying mechanical forces, the wire 110 can be mechanically loaded and, by removing these mechanical forces, unloaded. Furthermore, the roll 120 has a winding surface 122, which is intended to be wrapped with the wire 110 made of elastocaloric material. For this purpose, the wire 110 made of elastocaloric material is first mechanically locked at one end of the winding surface 122 and then wound several times around the winding surface 122 of the roll 120.

[0008] The wire 110 is then guided from the roller 120 to a counter bearing of the elastocaloric device 100, deflected, returned to the roller 120, and wound again around the winding surface 122 of the roller 120. The counter bearing can, for example, be formed by another roller 120. This process is repeated until the winding surface 122 of the roller 120 is completely wound. The wires 110 are thus, as shown, clamped in two planes E between the roller 120 and the counter bearing.

[0009] However, this type of clamping, known from the prior art, brings with it a number of problems.

[0010] The loading / unloading or tensioning / relaxing of the wire by applying and releasing mechanical forces on the roller leads to a relative movement of the wire with respect to the roller at the points of contact, i.e., at the winding surface. This causes friction between the wire and the roller, resulting in increased wear. Furthermore, the roller clamping design means that the wire is stressed at the bending radius and thus subjected to unfavorable deformation. The friction and the unfavorable mechanical stress therefore reduce the service life of the elastocaloric device.

[0011] Furthermore, the elastocaloric device requires a defined preload for operation. If the wire deforms plastically instead of elastically as intended under load / tension, the preload within the elastocaloric device is reduced and may no longer be sufficient. Plastic deformation therefore has a negative impact on the cooling / heating performance of the elastocaloric device.

[0012] Furthermore, if a wire is excessively plastically deformed and subsequently breaks, this leads to the failure of the entire wire bundle or wires that are stretched in the same plane E.

[0013] Furthermore, the production of the elastocaloric device with a roller-shaped clamping mechanism is complex. The prestress of the wire being applied must be maintained throughout the joining, winding, and assembly processes, right up to the point of use. Moreover, these manufacturing steps cannot be performed in a single clamping device, further complicating the maintenance of the prestress.

[0014] The cooling / heat conduction to be achieved by the elastocaloric device depends in a special way on the surface of the elastocaloric wire, which comes into contact with a coolant intended for heat exchange.

[0015] According to the state of the art, one measure to increase the cooling capacity of a device is therefore to combine several clamping points and / or several bundles in one clamping point.

[0016] In Fig. 2An exemplary combination of clamping devices known from the prior art is shown in a top view. In the elastocaloric device shown, in addition to the previously described roller 120, another roller 130 with a smaller diameter is provided. The corresponding elastocaloric devices 100 can thus be nested within each other. However, this combination has the disadvantage that the maximum elongation is always determined by the roller pair with the smaller diameter. This is because, due to the nesting, this roller pair spans a smaller distance and can therefore experience a smaller elongation path. The maximum elongation is thus not achieved with the outer roller pair with the larger diameter, meaning that the full efficiency of this roller pair cannot be exploited.

[0017] Document US 2012 / 019216 A1 discloses a power supply with an ultracapacitor configured to be charged by a DC power source. The power supply also includes a first switch that allows the ultracapacitor to be charged by the DC power source when it is in a closed position and disables charging when it is in an open position. The power supply further includes a second switch configured to allow the ultracapacitor to be discharged when it is in a closed position and disables discharge when it is in an open position. When the ultracapacitor is discharged, a current is applied to actuate a shape-memory alloy element.The power supply is configured to discharge the ultracapacitor to provide a current to actuate a shape memory alloy (SMA) element.

[0018] Document CN 112 963 985 A discloses a cooling device based on a shape memory alloy. The cooling device comprises two rotating disks arranged opposite each other in an inclined mode and a plurality of shape memory alloy wires connected between the two disks. The shape memory alloy wires are arranged parallel to each other and in the circumferential direction of the disks. Compared to an existing cooling system, the shape memory alloy-based cooling device has low energy consumption, is quiet, does not produce greenhouse gases such as carbon dioxide, and has high cooling efficiency.

[0019] Document US 4,922,718 A discloses a further device according to the preamble of claim 1 comprising a thermoelastic material.

[0020] Against this background, the object of the present invention is to provide an elastocaloric device, a clamping device, and a method for manufacturing an elastocaloric device, by means of which more efficient cooling performance and / or higher failure protection can be achieved. This object is achieved by an elastocaloric device according to claim 1 and a method according to claim 7.

[0021] Advantageous embodiments and further developments of the invention result from the dependent claims.

[0022] The elastocaloric device according to the invention is configured or designed to assume a first state in which an elastocaloric material emits heat energy based on the elastocaloric effect, and a second state in which the elastocaloric material absorbs heat energy based on the elastocaloric effect, and the elastocaloric device comprises: several elements formed from an elastocaloric material, and at least two opposing clamping devices which clamp respective end sections of each element in such a way that only a central section of each element lying between the opposing clamping devices can be moved into the first state and the second state for heat energy absorption and heat energy release.

[0023] Preferably, one or more of the elastocaloric devices according to the invention are installed or incorporated in an elastocaloric machine.

[0024] The respective end sections of each element are thus advantageously clamped firmly between sections / clamping elements of each clamping fixture. Preferably, the clamping of the respective end sections is achieved by means of line or surface pressure applied by the clamping elements.

[0025] The elastocaloric effect describes the property of certain elastocaloric materials to react to changes in mechanical stress applied to the material by cooling or heating.

[0026] Preferably, the clamping devices are arranged to bring about the first and second states of the multiple elements by bringing about the first state by exerting force, e.g. by loading or clamping, on the multiple elements via the clamping devices, and the second state by relaxing the multiple elements while removing the force.

[0027] Preferably, two opposing clamping devices and the multiple elements can form an elastocaloric cell, and several such cells can be provided in the elastocaloric device.

[0028] When a mechanical load is applied to an elastocaloric material, a crystalline phase transformation occurs, causing the material to heat up. In this initial state, the generated heat energy can be dissipated to the surroundings, allowing the material to cool back down to its initial temperature. If the mechanical load is subsequently removed, the crystalline phase transformation occurs in reverse, with the material cooling down. In this second state, the elastocaloric material can absorb heat energy from the surroundings. By cyclically loading and unloading the material, and by correspondingly supplying and removing heat energy, a cycle can be created that can be used for both heating and cooling.Examples of elastocaloric materials are shape memory alloys such as nickel-titanium, which undergoes a crystalline phase transformation from a cubic austenite structure to a metastable martensite structure under mechanical stress.

[0029] The elements made of elastocaloric material are preferably designed as thin strips, tubes or wires so that the largest possible surface area is available for heat dissipation and heat absorption within a given volume of the element.

[0030] A mechanical load can preferably be caused by stretching, compression, bending, shearing or torsion, whereby the deformation of the material by the mechanical load should occur within the elastic range of the material.

[0031] Furthermore, the elastocaloric device according to the invention can be designed such that the central sections of the several elements have a uniform length and / or the respective end sections of the elements are clamped firmly in the clamping devices.

[0032] A key advantage is that the end sections of the elements are clamped in a fixed / immovable manner relative to the clamping fixture. This minimizes friction between the fixture and the elements. Furthermore, under mechanical stress, there is no relative movement between the fixture and the end sections of the elements. This increases the element's service life.

[0033] A further advantage is the individual clamping of the elements in the fixture via their respective end sections. This means that if one element breaks, only that specific element fails, while the elastocaloric device with the remaining elements remains operational due to the individual clamping. Ideally, this also means that only the central sections are subjected to stress and unstress, or tension and relaxation, to release or absorb heat energy. The central sections should preferably not be subjected to any other stresses, such as friction, thus increasing the service life of the elements. The uniform length of the central sections preferably ensures that the mechanical stress is the same for all of them. If the mechanical stress is caused, for example, by elongation, all central sections experience the same elongation due to their uniform length and consequently deliver the same heat output.The variance between the individual elements is thus minimized.

[0034] In the elastocaloric device according to the invention, each clamping fixture has several spheroidal / ellipsoidal shell elements of different sizes, which are joined together in such a way that the end sections of the several elements are clamped between adjacent shell elements.

[0035] A spheroid / ellipsoid of revolution is a three-dimensional representation of a circular or elliptical surface, created by rotating it around one of its axes. Corresponding shell elements are therefore preferably formed by rotating circular or oval / elliptical surfaces. Preferably, hemispherical elements are created in this way, which can be structurally interlocked, for example, by using different dimensions.

[0036] Furthermore, the elastocaloric device according to the invention can be further developed such that a first shell element and an adjacent second shell element clamp end sections from a one-piece first bundle of several elements, and the second shell element and an adjacent third shell element clamp end sections from a one-piece second bundle of several elements that differs from the first bundle.

[0037] Preferably, a bundle comprises several elements arranged geometrically in a predefined manner. For example, the multiple elements are aligned in a circular or elliptical arrangement. With multiple bundles, this results in a concentric arrangement of the bundles radially, for example circularly or elliptically, around a common longitudinal axis of the adjacent shell elements.

[0038] Furthermore, a bundle is preferably clamped between nested or adjacent shell elements. A bundle can also be made in one piece such that it has several interconnected or linked or one-piece elements.

[0039] Alternatively, the elastocaloric device can be further developed such that the first shell element, the adjacent second shell element, and the adjacent third shell element clamp end sections of a single, one-piece bundle. In other words, the single, one-piece bundle with its connected elements can extend over several shell elements.

[0040] Preferably, the bundles differ in the dimensions of the predefined geometric arrangement, for example in diameter.

[0041] The interlocking shell elements in combination with the bundles are advantageous because better use of installation space can be achieved.

[0042] Preferably, the first shell element is designed as a hemispherical shell with a minimum radius or as an ellipsoidal shell with minimum semi-axes, wherein each subsequent shell element, also a hemispherical or ellipsoidal shell with a progressively larger radius or semi-axes, adjoins the next shell element with a smaller radius or semi-axes. Furthermore, the shell elements can be designed as ellipsoidal hemispheres.

[0043] Preferably, the hemispherical or ellipsoidal shells have, in addition to a spheroidal / ellipsoidal section, a cylindrical section. The clamping of the multiple elements within the cylindrical section ensures that the load on the elements can be applied along their longitudinal direction, thus preventing any load at the bending radius.

[0044] Alternatively, adjacent shell elements can be clamped against each other using fasteners.

[0045] Not according to the invention, the respective clamping devices are designed in the form of a plate which has several clamping devices distributed in the circumferential direction for clamping end sections of respective elements.

[0046] It is advantageous if the plate is designed as a circular disk with a flat surface. Furthermore, the clamping devices can be arranged in a star shape on the plate.

[0047] A corresponding clamping device can have a recess and a corresponding clamping element that can be inserted into the recess, wherein the clamping element can be inserted into the recess in such a way that the end sections of the several elements are clamped between the recess and the clamping element clamped therein.

[0048] It is advantageous if the recess and the clamping element can be positively fitted together. The recesses and clamping elements can, for example, be implemented in the form of a tongue-and-groove connection, with the elements being clamped between the groove and the tongue.

[0049] A bundle preferably comprises several elements that are clamped together in the clamping device. Multiple bundles can be distributed along the circumference of the plate. This allows for efficient and scalable use of installation space by accommodating more elements within the available space.

[0050] The recess and the corresponding clamping element that can be inserted into the recess preferably clamp end sections of elements of a bundle.

[0051] The clamping can preferably be secured by crimping, gluing or welding.

[0052] Preferably, the clamping element has a further recess into which a further corresponding clamping element can be inserted, wherein the further clamping element can be inserted into the further recess in such a way that the end sections of the several elements are clamped between the further recess and the further clamping element clamped therein.

[0053] The further recess and the corresponding further clamping element that can be inserted into the further recess preferably clamp end sections of elements of another bundle.

[0054] Preferably, the clamping devices are designed as disks, preferably as circular disks.

[0055] The clamping device according to the invention for clamping several elements made of an elastocaloric material comprises: at least a first clamping part and a second clamping part which are joined together in such a way that end sections of the several elements can be clamped securely between the first clamping part and the second clamping part.

[0056] With regard to the clamping, the properties and advantages explained in connection with the elastocaloric device according to the invention arise in the same or similar way, which is why reference is made to the preceding explanations to avoid repetition.

[0057] The inventive method for producing an elastocaloric device according to the invention, which is configured to assume a first state in which an elastocaloric material absorbs heat energy based on the elastocaloric effect, and a second state in which the elastocaloric material releases heat energy based on the elastocaloric effect, comprises the following steps: Clamping several elements formed from an elastocaloric material in at least two opposing clamping devices, which clamp respective end sections of each element in such a way that only a central section of each element located between the opposing clamping devices can be moved into the first state and the second state for heat energy absorption and heat energy release.

[0058] It is advantageous if the clamping elements are pre-positioned in a fixture. This allows the entire manufacturing process to be carried out sequentially within the fixture. Parts of the clamping elements are added one after the other, and the elements of each bundle are applied in the immediately following sub-process. The elements are applied across the entire bundle under continuous and homogeneous pre-tension through a controlled element placement process (monitoring of the wire tension). This results in an assembly-friendly process that also offers high automation potential.

[0059] Furthermore, with regard to the method, the properties and advantages explained in connection with the elastocaloric device according to the invention arise in the same or similar way, which is why reference is made to the preceding explanations to avoid repetition.

[0060] Preferred embodiments of the invention are explained below with reference to the accompanying drawings. Figure 1 shows a perspective view of an elastocaloric device known from the prior art. Figure 2 shows a top view of a combination of two of the clamping devices known from the prior art. Figure 3 shows a perspective cross-sectional view of an elastocaloric device according to a first embodiment of the invention. Figure 4 shows a longitudinal sectional view of the elastocaloric device according to the invention. Fig. 3 . Figures 5A to 5C show a method according to the invention for manufacturing the elastocaloric device according to the invention in the first embodiment of the invention. Figures 6A to 6C show the device according to the invention in a modification of the first embodiment. Figure 7Figure 1 shows a perspective cross-sectional view of an elastocaloric device with first bundles that is not according to the invention. Figure 8 shows a method for manufacturing the elastocaloric device according to Figure 7 in a perspective exploded view. Figure 9 shows a perspective view of the elastocaloric device according to Figure 7 with initial bundles. Figure 10A and 10B show a perspective view of the elastocaloric device according to Figure 7 with initial bundles in constructively modified forms. Figure 11 shows a perspective cross-sectional view of a opposite Figure 7 modified elastocaloric device with first and second bundles. Figure 12 shows a perspective view of the elastocaloric device of Figure 11 with first bundles and second bundles in a perspective exploded view. Figure 13shows a non-inventive method for manufacturing the elastocaloric device of Figure 11 with first bundles and second bundles based on an exploded view.

[0061] Figure 3 Figure 1 shows a perspective cross-sectional view of an elastocaloric device 200 according to a first embodiment of the invention. One or more of these elastocaloric devices 200 can be installed or incorporated in an elastocaloric machine. The elastocaloric device 200 comprises several elements 210 made of an elastocaloric material. These elements 210 are clamped in two opposing clamps 220, although only one of the two clamps 220 is shown in the cross-sectional view. The opposing clamps 220 and the associated elastocaloric elements 210 are preferably configured as one or more elastocaloric cells.

[0062] In the specific case shown, the elements 210 are designed as thin wires with a circular cross-section. The elements 210 are grouped or combined into bundles, each bundle comprising a plurality of elements 210 that are connected to one another. Each bundle is thus a single, continuous bundle of several interconnected elements 210. Within each bundle, the individual elements 210 are arranged radially around a longitudinal axis LA of the elastocaloric device 200 at the same radius and thus form a grouping. Different bundles therefore have elements 210 arranged at different radii around the longitudinal axis LA of the elastocaloric device 200. Within a bundle, the distance of the elements 210 to the longitudinal axis LA is therefore always uniform. In the first embodiment shown, the elastocaloric device 200 comprises three concentric bundles B1-B3 of elements 210.

[0063] Figure 4 shows a longitudinal sectional view of the elastocaloric device 200 according to the invention. Fig. 3 . How Fig. 4As can be seen, the clamping device 220 comprises four hemispherical shell elements 221-224 of different sizes, which are joined together. The first hemispherical shell element 221 has the smallest radius, and each subsequent shell element 222-224 borders the next shell element with a larger radius, each with a smaller radius. End sections 211 of the elements 210 are fixedly clamped in the clamping device 220 between the adjacent surfaces of the shell elements 221-224. The elements 210 of the first bundle B1 are fixedly clamped between the first shell element 221 and an adjacent second shell element 222. The elements 210 of the second bundle B2 are fixedly clamped between the second shell element 222 and an adjacent third shell element 223.Furthermore, the elements 210 of the third bundle B3 are clamped between the third shell element 223 and an adjacent fourth shell element 224. The shell elements 221-224 form a common surface A on one side of the (first) clamping point 220, which faces the opposite second clamping point (not shown). Thus, the midsections 212 of the elements 210, which lie between the two opposite clamping points 220, have a uniform length. The midsections 212 are free and therefore designed for heat exchange with the environment.

[0064] Furthermore, the shell elements 221-224 have a concentric bore B. The shell elements 221-224 can be clamped together or against each other via this bore using a fastening device (not shown).

[0065] Figures 5A to 5Cshow a method according to the invention for producing the elastocaloric device 200 according to the first embodiment of the invention. Step 1 (Figure 5A)

[0066] The first shell elements 221, which have the smallest radius, are pre-positioned opposite each other in a photograph not shown. Subsequently, the multiple elements 210 of the first bundle B1 are applied to the first shell elements 221, such that the respective end sections 211 of the elements 210 of the first bundle B1 are in contact with the first shell elements 221 and the middle sections 212 between the two opposing first shell elements 221 are exposed. Step 2 (Figure 5B)

[0067] Subsequently, the second shell elements 222 with the next larger radius are joined together with the first shell elements 221 with the smallest radius, so that the end sections 211 of each element 210 of the first bundle are clamped firmly between the adjacent surfaces of the first shell elements 221 and the second shell elements 222, while the middle sections 212 remain exposed. Step 3 (Figure 5C)

[0068] Subsequently, the multiple elements 210 of the second bundle B2 are applied to the second shell elements 222, such that the respective end sections 211 of the elements 210 of the second bundle B2 are in contact with the second shell elements 222 and the middle sections 212 between the two opposing second shell elements 222 are exposed. Following this, further shell elements (e.g., 223 in Fig. 4 ) and bundles (e.g. B3 in Fig. 4) are added or attached until final shell elements (e.g. 224 in Fig. 4 ) are applied.

[0069] Figures 6A to 6C show the device 200 according to the invention in a modification of the first embodiment, wherein the several elements 210 are formed in one piece.

[0070] Figure 6A This shows a first possibility of forming the several elements 210 of the first bundle as a single-piece element, or as a single-piece bundle of several elements 210. For this purpose, the first shell element 221 comprises cylindrical guide elements 2211 in the form of protruding short bolts, which are arranged radially around the longitudinal axis LA on the adjacent surface of the first shell element 221.

[0071] The single-piece first bundle is initially guided from one first shell element 221 to another first shell element 221. The first shell elements 221 are then rotated about the longitudinal axis LA, whereby the single-piece bundle is first guided by a first cylindrical guide element 2211 of the other first shell element 221 and placed in a groove formed in the other first shell element 221. Subsequently, the single-piece bundle is guided around a second guide element 2212 on the other first shell element 221 and then returned to the first shell element 221. This process is repeated until all cylindrical guide elements 2211 are covered with the single-piece bundle.

[0072] Figure 6BFigure 2 shows a second possibility for forming the multiple elements 210 of the first bundle as a single-piece element, or as a single-piece bundle of multiple elements 210. The first shell element 221 also includes the cylindrical guide elements 2211, which are arranged radially around the longitudinal axis LA on the adjacent surface of the first shell element 221.

[0073] The single-piece bundle is first guided from one first shell element 221 to the other first shell element 221. The single-piece bundle is then guided around a first cylindrical guide element 2211. Subsequently, the single-piece bundle is guided back to one of the shell elements 221 and around a second cylindrical guide element 2212. The single-piece bundle is thus applied to the first shell elements 221 in a meandering pattern. An exemplary result of this process is shown in Figure 6C shown.

[0074] Figure 7shows a perspective cross-sectional view of an elastocaloric device 300 according to a non-inventive embodiment with first bundles B11-B14. Figure 8 Figure 1 shows a method for manufacturing the elastocaloric device 300 in a perspective exploded view. One or more of these elastocaloric devices 300 can be installed or incorporated in an elastocaloric machine.

[0075] The elastocaloric device 300 comprises several elements 310 formed from an elastocaloric material. These elements 310 are clamped in two opposing fixtures 320, although only one of the two fixtures 320 is shown in the cross-sectional view. The opposing fixtures 320 and the elastocaloric elements 310 can also be configured as one or more elastocaloric cells.

[0076] In the specific case shown, the elements 310 are designed as thin wires with a circular cross-section. Furthermore, the elements 310 are grouped or combined into the first four bundles B11-B14.

[0077] The clamping device 320 comprises a first clamping element 321, which in the illustrated case is designed as a plate / circular disk. The first clamping element 321 / the plate has four clamping devices distributed circumferentially for clamping end sections 311 of respective elements 310 of the first bundles B11-B14.

[0078] The first clamping element 321 / the plate includes projections on one side that have recesses 3211-3214, with corresponding clamping elements 3221-3224 being provided that can be inserted into the recesses 3211-3214. The insertable clamping elements 3221-3224 are connected to each other via a connecting element to form a second clamping element 322 or are formed in one piece. The end sections 311 of the elements 310 are clamped or fixedly clamped between adjacent surfaces of the recesses 3211-3214 and the corresponding clamping elements 3221-3224.

[0079] The central sections 312 of the elements 310 of all first bundles B11-B14, which lie between the two opposing clamping points 320, have a uniform length. The central sections 312 are exposed and thus designed for heat exchange with the environment.

[0080] Furthermore, the first clamping element 321 / the plate on which the projections with the recesses 3211-3214 are formed, and the second clamping element 322, which has the clamping elements 3221-3224, each have a concentric bore. The corresponding clamping elements 3221-3224 and the respective recesses 3211-3214 can be clamped together or against each other via this bore using a fastening device, in the case shown, a screw S.

[0081] The first clamping part 321 / the plate which has the recesses 3211-3214 is pre-positioned in a photograph not shown.

[0082] Subsequently, the recesses 3211-3214 of the first plate 321 are joined via the clamping elements 3221-3224, on which the several elements 310 of the first bundles B11-B14 are already arranged, so that the respective end sections 311 of the elements 310 of the first bundles B11-14 are clamped firmly in contact between the recesses 3211-3214 and the clamping elements 3221-3224 and the middle sections 312 are exposed.

[0083] Finally, the first clamping part 321 / the plate and the second clamping part 322, which has the clamping elements 3221-3224, are clamped against each other by inserting the screw S into the bore.

[0084] Figure 9 shows a perspective view of elastocaloric device 300 with first bundles B11-B14.

[0085] In the case shown, the clamping of the recesses 3211-3214 and the corresponding clamping elements 3221-3224 is additionally secured by bonding / welding 331 and / or by crimping 332 (connection by plastic deformation) of the respective corresponding pairings.

[0086] Figure 10A and 10B show a perspective view of the elastocaloric device 300 with first bundles in constructively modified forms.

[0087] The in Figure 10A The elastocaloric device 300 shown comprises five clamping devices distributed circumferentially for clamping end sections 311 of respective elements 310 of first bundles B11'-B15'.

[0088] The in Figure 10B The elastocaloric device 300 shown comprises six clamping devices distributed circumferentially for clamping end sections 311 of respective elements 310 of first bundles B11"-B16".

[0089] An increase in the number of clamping elements or the first bundles can be achieved to increase the packing density of the elastocaloric device 310.

[0090] Figure 11Figure 1 shows a perspective cross-sectional view of an elastocaloric device 400 according to a further, non-inventive embodiment with first bundles B11-B14 and second bundles B21-B24. One or more of these elastocaloric devices 400 can be installed or incorporated in an elastocaloric machine. The elastocaloric device 400 comprises several elements 410 formed from an elastocaloric material. These elements 410 are clamped in two opposing clamps 420, whereby, due to the cross-sectional view, only one of the two clamps 420 is shown. The opposing clamps 420 and the elastocaloric elements 410 can also be provided as one or more elastocaloric cells.

[0091] In the specific case shown, the elements 410 are designed as thin wires with a circular cross-section. Furthermore, elements 410 are subdivided into first bundles B11-B14 and second bundles B21-B24.

[0092] Figure 12 shows a perspective view of the elastocaloric device 400 with first bundles B11-B14 and second bundles B21-B24 in a perspective exploded view.

[0093] The clamping device 420 comprises a first clamping element 421, in the case shown a plate which, in the illustrated case, is designed as a circular disk. The plate 421 forms four clamping devices distributed circumferentially for clamping end sections 411 of respective elements 410 of the first bundles B11-B14.

[0094] The first clamping element 421, or plate, comprises projections on one side which have recesses 4211-4214, with corresponding clamping elements 4221-4224 being provided that can be inserted into the recesses 4211-4214. The insertable clamping elements 4221-4224 are connected to each other via a connecting element to form a second clamping element 422. The end sections 411 of the elements 410 of the first bundles B11-B14 are clamped or fixedly clamped between adjacent surfaces of the recesses 4211-4214 and the corresponding clamping elements 4221-4224.

[0095] Furthermore, the clamping elements 4221-4224 incorporate four additional clamping devices for securing the end sections 411 of the respective elements 410 of the second bundles B21-B24. For this purpose, the clamping elements 4221-4224 include further recesses 4221'-4224', with corresponding additional clamping elements 4231-4234 being provided that can be inserted into these further recesses 4221'-4224'. The additional clamping elements 4231-4234 are connected to each other via a further connecting element to form a third clamping element 423. The end sections 411 of the elements 410 of the first bundles B11-B14 are clamped securely between adjacent surfaces of the further recesses 4221'-4224' and the corresponding additional clamping elements 4231-4234.

[0096] The central sections 412 of the elements 410 of all first bundles B11-B14 and all second bundles B21-B24, which lie between the two opposing clamping points 420, have a uniform length. The central sections 412 are exposed and thus designed for heat exchange with the environment.

[0097] Furthermore, the first clamping element 421 / the plate on which the projections with the recesses 4211-4214 are formed, the second clamping element 422, which has the clamping elements 4221-4224, and the third clamping element 423, which has the further clamping elements 4231-4234, each have a concentric bore. The corresponding clamping elements 4221-4224 and the respective recesses 4211-4214, as well as the corresponding further clamping elements 4231-4234 and the respective recesses 4221'-4224', can be clamped together via this bore using a fastening device, in the case shown, a screw S.

[0098] Figure 13 shows a non-inventive method for producing the elastocaloric device 400 of Figure 12 based on an exploded view.

[0099] The following will be discussed Figure 13 in conjunction with Figure 12 referred.

[0100] The plate or the first clamping part 421, which has the projections with the recesses 4211-4214, the second clamping part 422, which includes the clamping elements 4221-4224 and the further recesses 4221'-4224', and the third clamping part 423, which includes the further clamping elements 4231-4234, are pre-positioned in a photograph not shown.

[0101] First, the further clamping elements 4231-4234 of the third clamping part 423 are wrapped with the several elements 410 of the second bundles B21-B24.

[0102] Subsequently, the second clamping part 422 is positioned by applying the further recesses 4221'-4224' to the further wrapped clamping elements 4231-4234, so that the respective end sections 411 of the elements 410 of the second bundles B21-24 are firmly clamped between the recesses 4221'-4224' and the further clamping elements 4231-4234 and the middle sections 412 are exposed.

[0103] Subsequently, the clamping elements 4221-4224 of the second clamping part 422 are wrapped with the several elements 410 of the first bundles B11-B14.

[0104] The first clamping element or plate 421 is then positioned by creating the recesses 4211-4214 on the wrapped clamping elements 4221-4224, so that the respective end sections 411 of the elements 410 of the first bundles B11-14 are firmly clamped between the recesses 4211-4214 and the clamping elements 4221-4224, and the middle sections 412 are exposed. Finally, the plate / first clamping element 421, the second clamping element 422, which includes the clamping elements 4221-4224, and the third clamping element 423, which includes the further clamping elements 4231-4234, are clamped together by inserting the screw S into the bore.

[0105] The features of the invention disclosed in the foregoing description, in the drawings, and in the claims may be essential for the realization of the invention, both individually and in any combination.

Claims

1. Elastocaloric device (200) which is configured to assume a first state, in which an elastocaloric material gives off heat energy on the basis of the elastocaloric effect, and a second state in which the elastocaloric material takes up heat energy on the basis of the elastocaloric effect, wherein the elastocaloric device (200) comprises: a plurality of elements (210) made of an elastocaloric material, and at least two oppositely situated clamping means (220) which clamp respective end portions (211) of each element (210) in such a way that only a centre portion (212) of each element (210) that lies between the oppositely situated clamping means (220) can be offset in the first state and the second state to take up heat energy and give off heat energy, characterized in that each clamping means (220) has multiple spheroidal shell elements (221-224) which have different sizes and are inserted one in another in such a way that the end portions (211) of the plurality of elements (210) are clamped between adjoining shell elements (221-224).

2. Elastocaloric device (200) according to Claim 1, wherein the clamping means (220) are configured to bring about the first and the second state of the plurality of elements (210) by virtue of the first state being brought about by exertion of a force on the plurality of elements (210) via the clamping means (220) and the second state being brought about by relieving the tension in the plurality of elements (210) by stopping the exertion of force.

3. Elastocaloric device (200) according to Claim 1 or 2, wherein the centre portions (212) of the plurality of elements have a uniform length and / or the respective end portions (211) of the plurality of elements (210) are fixedly clamped in the clamping means (220).

4. Elastocaloric device (200) according to one of the preceding claims, wherein a first shell element (221) and an adjoining second shell element (222) clamp end portions (211) of a one-piece first bundle (B1) consisting of a plurality of elements (210), and the second shell element (222) and an adjoining third shell element (223) clamp end portions (211) of a one-piece second bundle (B2) which is different from the first bundle (B1) and consists of a plurality of elements (210).

5. Elastocaloric device (200) according to Claim 4, wherein the first shell element (221) is designed in the form of a hemispherical shell with a smallest radius or in the form of an ellipsoidal shell with smallest half-axes and each further shell element (222-224) in the form of a hemispherical or ellipsoidal shell with a respective larger radius or respective larger half-axes adjoins the respective next shell element with a smaller radius or smaller half-axes.

6. Elastocaloric device (200) according to Claim 4, wherein adjoining shell elements (221-224) can be braced against one another via fastening means (S).

7. Method for producing an elastocaloric device (200) according to one of Claims 1 to 6, which is configured to assume a first state, in which an elastocaloric material takes up heat energy on the basis of the elastocaloric effect, and a second state in which the elastocaloric material gives off heat energy on the basis of the elastocaloric effect, wherein the method comprises the following steps: clamping a plurality of elements (210) made of an elastocaloric material in at least two oppositely situated clamping means (220) which clamp respective end portions (211) of each element (210) in such a way that only a centre portion (212) of each element (210) that lies between the oppositely situated clamping means (220) can be offset in the first state and the second state to take up heat energy and give off heat energy.