THERMOELASTIC POWER CONVERTER SYSTEM WITH THERMOELASTIC POWER CONVERTER AND THERMOELASTIC POWER CONVERTER

Abstract

The invention relates to a thermoelastic energy converter system (10) comprising a thermoelastic energy converter (11) with a thermoelastic element (12) as a first component and a chamber wall (15) at least partially enclosing the at least one thermoelastic element (12), wherein the chamber wall (15) defines a chamber (14) as a second component in which the thermoelastic element (12) is arranged.The invention provides that the at least one thermoelastic element (12) is designed as a fluidically tight hollow structure (13) relative to the chamber (14), and that the hollow structure (13) is arranged to penetrate the chamber wall (15) at at least one point, wherein the hollow structure (13) is fluidically tightly enclosed by the chamber wall (15) at this respective point, and one of the two components has two fluidically permeable openings (16) and is thus fluidically permeable, and the other component has at least one opening (17) through which it is coupled to a pressurization device by means of which it can be pressurized with a fluid pressure to deform the thermoelastic element (12). Furthermore, the invention relates to a thermoelastic energy converter (12) for a thermoelastic energy converter system (10).

Description

Technical field

[0001] The invention relates to a thermoelastic energy converter system comprising at least one thermoelastic energy converter with at least one thermoelastic element as a first component and a chamber wall at least partially enclosing the at least one thermoelastic element, wherein the chamber wall defines or forms a chamber as a second component in which the at least one thermoelastic element is at least partially arranged. The invention further relates to a thermoelastic energy converter for such an energy converter system. Technical background and task

[0002] Thermoelastic materials, also called mechanoelastic, elastocaloric, or shape memory materials, can heat up under mechanical stress, thereby releasing heat energy to their surroundings, or cool down and absorb heat from the environment. In shape memory alloys, i.e., metallic shape memory materials, latent heat or phase change enthalpy is released under mechanical stress as a result of a change in their crystal lattice structure. The crystal lattice structure of shape memory alloys can reversibly transform from an austenitic crystal lattice structure to a martensitic crystal lattice structure and back again, depending on their temperature and / or mechanical stress and / or deformation and / or strain. Temperature and mechanical stress are equally important in this process.Under load, particularly compressive or tensile stress, a thermoelastic or elastocaloric element, for example, consisting of a shape-memory alloy, can transform from a martensitic crystal lattice or a martensitic phase into an austenitic phase, releasing the phase change enthalpy. During this process, the thermoelastic element heats up. Upon unloading, it transforms back into the martensitic phase, absorbing the phase change enthalpy and thus cooling down. An energy converter comprising such a thermoelastic element can be used to induce a temperature change in the element through mechanical loading and unloading, or to reversibly convert mechanical energy or deformation energy into heat energy.By cyclically or periodically loading and unloading a thermoelastic element, a thermodynamic cycle can be realized for heating and / or cooling devices, analogous to compression refrigeration machines. Under mechanical stress, or during mechanical stress (e.g., tensile, compressive, bending, torsional, or shear stress), the latent heat can be transferred to a heat sink, such as a refrigerant or working fluid in a refrigerant circuit, and / or to the surroundings. The heat sink must have a lower temperature than the heated thermoelastic element. Upon subsequent unloading, the thermoelastic element cools down and can itself absorb heat from the surroundings and / or the refrigerant.

[0003] DE 10 2016 118 776 A1 discloses a thermoelastic energy converter for use in an energy converter system in which thermoelastic elements are guided in a cylindrical arrangement, such that a change in length of the thermoelastic elements is caused by synchronous rotation of the thermoelastic elements, resulting in cyclic elastic deformation and relaxation of at least one thermoelastic element, whereby heat is released or absorbed.

[0004] DE 10 2019 113 696 A1 discloses a thermoelastic energy converter comprising an arrangement with several converter devices, wherein each converter device has thermoelastic elements arranged in a stretching direction, an actuation device to subject the thermoelastic elements of each of the converter devices to a force profile that varies over time, and a coupling by means of which the converter devices are controlled in a phase-shifted manner with respect to their cyclic loading and unloading.

[0005] US Patent 2025 / 0102200A1 discloses a barocaloric refrigeration machine for ambient temperatures, comprising a high-precision, high-pressure electric injection pump, a barocaloric element, a heat exchange fluid, a cold-side heat exchanger, and a hot-side heat exchanger. A phase change in a barocaloric medium, driven by the high-pressure injection pump, results in heat release during pressure increase and heat absorption during pressure decrease. The heat exchange fluid circulates between the barocaloric refrigeration units, enabling the exchange of heat and cold. The high-precision, high-pressure electric injection pump generates the pressure required for the barocaloric refrigeration cycle. The pressurized oil simultaneously acts as the heat exchange fluid and is in direct contact with a sample. The heat and cold generated by the pressure are transferred directly to the hot-side and cold-side heat exchangers, respectively.Cold-side heat exchangers were installed, thus completing the cycle and reducing heat losses.

[0006] The publication "High-performance cooling and heat pumping based on fatigue-resistant elastocaloric effect in compression" by Z. Ahcin et al. describes an elastocaloric or thermoelastic energy converter system for an elastocaloric cooling / heating circuit with multiple elastocaloric or thermoelastic elements designed as rods. These elements are cyclically compressed along their longitudinal direction using a type of vise or press, and subsequently released. During compression, the rods heat up, and shape memory materials or shape memory alloys can react thermally to tensile and compressive stress in varying degrees, either individually or in combination.

[0007] A problematic or disadvantageous aspect of using thermoelastic elements designed as rods is that they can fail under longitudinal loading, particularly buckling under compressive stress, even though the thermoelastic or elastocaloric effect is maintained over a large number of loading cycles. Such thermoelastic elements can therefore become unusable even before the end of their potential service life.

[0008] The invention is based on the objective of providing a particularly durable and / or robust thermoelastic energy converter system and a thermoelastic energy converter for such an energy converter system. Disclosure of the invention

[0009] The problem is solved by the subject matter of the independent patent claims. Advantageous embodiments of the invention are described by the dependent patent claims, the following description, and the figures.

[0010] Shortening thermoelastic elements designed as rods to reduce the risk of buckling or to increase buckling stress is limited by the fact that, for each mass of shape memory material, there must be sufficient surface area of ​​the thermoelastic element to exchange heat with it as quickly as possible in order to provide a sufficiently high overall performance of a thermoelastic energy converter system.

[0011] A first aspect of the invention relates to a thermoelastic energy converter system comprising at least one thermoelastic energy converter with at least one thermoelastic element as a first component and a chamber wall at least partially enclosing the at least one thermoelastic element, wherein the chamber wall defines a chamber as a second component in which the at least one thermoelastic element is at least partially arranged.The energy converter system is characterized in that the at least one thermoelastic element is designed as a fluidically tight hollow structure relative to the chamber, and the hollow structure is arranged to penetrate the chamber wall at at least one point, wherein the hollow structure is fluidically tightly enclosed by the chamber wall at this respective point, and at least one of the two components has at least two fluidically permeable openings and is thus fluidically permeable, and the other component has at least one opening through which it is coupled to a pressure-applying device by means of which it can be pressurized with a time-varying fluid pressure by means of which the at least one thermoelastic element can be deformed.In other words, the thermoelastic element, designed as a hollow structure, should be at least partially arranged within the chamber and be deformable or load-bearing fluidically or hydrostatically by means of the pressurization device. Depending on which component—the chamber or the chamber wall, or the hollow structure—is at least fluidically accessible and thus compressible via the at least one opening, and which component, for example, for heat exchange with the thermoelastic element, has at least two openings, the hollow structure or its wall can withstand tension when compressed from the inside or compression when compressed from the outside. "Inside" here refers to the cavity of the thermoelastic element designed as a hollow body, and "outside" refers to the chamber.The hollow structure can, for example, be at least partially designed as a hollow sphere, with a portion of the hollow structure serving as a supply line or fluidic connection to the pressurization device and penetrating the chamber wall. In this case, if the hollow structure, as the other component, has at least one opening, this opening can be arranged at one end of the supply line outside the chamber wall and be fluidically connectable to the pressurization device or connected within an operating mechanism of the energy conversion system. The pressurization device can be a pump or compressor known from the prior art. The pressurization fluid can be a liquid fluid, in particular water or oil, or a gaseous and / or vaporous fluid.The other component can have at least one or more openings through which it can be subjected to fluid pressure, such that the hollow structure can be subjected to pressure, at least indirectly, by applying pressure to this component. Additionally or alternatively, the other component, like the at least one component, can have multiple openings through which fluid can flow. Additionally or alternatively, the other component, or the at least one component to be subjected to pressure, can be subjected to fluid flow when subjected to pressure, i.e., flow can occur during operation of the energy conversion system when pressure is applied. In particular, in the case of the hollow structure as the other component, or the component to be subjected to pressure, it can extend through the chamber, for example, with two openings, and thus be only partially located within the chamber.At each point of penetration, the chamber wall should be fluidically sealed against the wall of the hollow structure, preventing any fluid from escaping the chamber into the environment, for example, through a gap between the chamber wall and the wall of the hollow structure. The thermoelastic energy converter system can comprise one or more thermoelastic energy converters; therefore, only one thermoelastic energy converter is described below. Each thermoelastic energy converter can comprise one or more thermoelastic elements or hollow structures, but only one thermoelastic element in a thermoelastic energy converter is described below as an example.

[0012] The first aspect of the invention also includes embodiments or further developments that result in additional advantages.

[0013] A further development of the thermoelastic energy converter system provides that at least one of the two components is coupled to a refrigerant circuit via at least two fluid-flowable openings in order to absorb heat from and / or transfer heat to the at least one thermoelastic element. In other words, at least one of the two components should be connectable to the refrigerant circuit via at least two openings and be permeable to its refrigerant, or be permeated during operation of the energy converter system, while at least the other of the two components is connectable to the pressure application device via its at least one opening for loading the thermoelastic element. The refrigerant circuit can be enclosed within the thermoelastic energy converter system.To maintain the cycle, the refrigerant circuit has at least one heat source and / or one heat sink, to which the refrigerant can be supplied, for example, depending on the current load state of the thermoelastic element. The heat source can be a heat exchanger of the refrigerant circuit, through which heat released to the refrigerant, for example, when the thermoelastic element is unloaded, can be transferred back to it. The heat sink can be the same or another heat exchanger of the refrigerant circuit, through which the refrigerant can release heat absorbed, for example, when the thermoelastic element is loaded. The refrigerant circuit can, for example, have a valve, located particularly downstream of the component coupled to it, to cyclically direct refrigerant to the heat source or heat sink of the refrigerant circuit.Additionally or alternatively, it is provided that the refrigerant can or does flow through the refrigerant circuit in the opposite direction, at least in one area for heat exchange with the thermoelastic element, under different load conditions of the thermoelastic element. Coupling at least one component with the refrigerant circuit offers the advantage that a cyclic process or a thermodynamic cycle for heating and / or cooling can be provided particularly efficiently. Solutions known from the prior art can be used for the refrigerant in the refrigerant circuit.For example, water, distilled water, and / or oil can be used as the refrigerant, wherein the refrigerant can be in liquid form or phase throughout the entire refrigerant circuit and / or during each load cycle, i.e., during the periodically successive loading and unloading of the thermoelastic element. In particular, it is provided that the refrigerant does not change its phase or state of matter as a result of heat transfer between it and the thermoelastic element. Additionally or alternatively, both components, i.e., the chamber and the hollow structure, can have at least two openings and be coupled to a refrigerant circuit, either one around the same circuit or to separate circuits, with at least one refrigerant circuit potentially including the pressurization device.Depending on the current load state of the thermoelastic element, both components can be used for heat exchange with the element. However, particularly under load, only one component can compress or load the thermoelastic element. This compressing component can, for example, have additional openings that are fluidically sealed, except for one opening, which can be closed to compress or load the thermoelastic element. Thus, under load, it can be designed so that no fluid or refrigerant can flow through this component, while the other component is supplied with refrigerant. If a refrigerant circuit is coupled to the pressurization device, the fluid used to compress or load the thermoelastic element can be the refrigerant of that circuit.Additionally or alternatively, both components are each coupled to a refrigeration circuit with a pressure device, in particular to one of two separately designed refrigerant circuits, whereby not only a loading state and a relieving state can be provided for the thermoelastic element, but two opposing loading states. For example, in a first loading state, the hollow structure can be compressed from the chamber, i.e., subjected to pressure; after a reduction of the chamber pressure, it can assume a relieved loading state, which can then immediately transition into a second loading state by compressing the hollow structure from the inside, in which the hollow structure is subjected to tensile stress.In the first loading state, an initial temperature extreme can occur, for example, a temperature minimum or maximum of the hollow structure, and in the second loading state, a more extreme, opposite temperature extreme can occur than in the unloaded state. This design is particularly efficient for linear thermoelastic elements or shape memory materials, which, starting from an unloaded initial state with a certain temperature, heat up under tension or compression and cool down under the opposite loading, i.e., compression or tension. A particularly large temperature difference between the two temperature extremes allows the energy conversion system to operate very effectively, since the heat transfer between a coolant and the thermoelastic element—especially in the case of convective or mass flow-related heat transport or heat transfer—increases with a temperature difference between the coolant and the thermoelastic element.Additionally or alternatively, it is provided that a refrigerant circuit with a pressurization device is designed to allow the fluidically connected component, which is directly pressurized by the thermoelastic element, to continue to flow through it, either indirectly (via the chamber) or directly (directly in the hollow structure). In other words, it should be able to provide a variable static pressure in its refrigerant flow so that the refrigerant can continue to flow through the component during a pressurization. This offers the advantage, particularly when both components are connected, preferably via a separately designed refrigerant circuit, that heat exchange with the hollow structure can occur convectively on both sides of its wall, and thus be particularly efficient or rapid.

[0014] Additionally or alternatively, if one of the two components has only one opening for connection to the pressurization device, the side of the hollow structure's wall facing the cavity accessible through that single opening is thermally insulated. Thus, if the hollow structure has only one opening, the insulation is located on the inside of the wall; if the chamber has only one opening, the insulation is located on the outside of the hollow structure facing the chamber. This offers the advantage of significantly reducing the heat transferred from the hollow structure to the pressurizing fluid, which, due to the single opening, does not flow through either component, and / or is absorbed by the fluid during a limited period of pressure on the hollow structure.This significantly reduces the energy loss of the cycle and significantly increases its useful output. The thermal insulation can be made of materials such as rubber or plastic.

[0015] A further development of the thermoelastic energy converter system provides that the chamber is designed as a first hollow cylinder, wherein the chamber wall comprises a lateral surface or shell wall of the first hollow cylinder, a top plate, and a bottom plate arranged opposite the top plate along a central axis of the first hollow cylinder. In particular, it is provided that the lateral surface comprises the largest part of the outer surface of the chamber wall facing the environment. Due to the circular shape of the outer surface of the lateral surface around the central axis, the outer surface, i.e., the side of the lateral surface facing away from the chamber, can be particularly well thermally insulated from the environment (at least up to the so-called "critical radius"), thereby enabling the energy converter system to operate with particularly low losses.The design of the chamber wall as a hollow cylinder makes it particularly stable against compressive and / or tensile stresses, for example, resulting from overpressure or underpressure within the chamber. This allows the chamber wall to be designed to be especially robust and / or lightweight. At least one penetration of the chamber wall through the hollow structure is provided, particularly in the area of ​​the top plate and / or the bottom plate.

[0016] A further development of the thermoelastic energy converter system provides that the hollow structure is designed as a second hollow cylinder. In other words, the hollow structure is designed as a hollow cylinder with a wall that defines or encloses a cavity extending around and along the central axis of the hollow structure. If the cavity has at least one opening for compression, this opening is located at one end of the central axis, thus making the cavity at least fluidically accessible. If the cavity has two openings, these are each located at one of the two ends of the cavity, opposite each other along the central axis, thus allowing fluid to flow through it, for example, refrigerant. Even if the hollow cylinder is designed as a rod, i.e., with a dimension or length that is a multiple of its other dimensions, there is no risk of buckling for the thermoelastic element under load.The second hollow cylinder is not subjected to tensile or compressive stresses longitudinally or along its central axis, but rather radially. This makes the thermoelastic energy converter system particularly robust and / or durable. Furthermore, radial loading of the second hollow cylinder results in a particularly uniform stress and / or deformation distribution, thus ensuring exceptionally consistent thermal behavior of the hollow structure. Additionally, the second hollow cylinder advantageously provides a particularly high surface area ratio (of the outer and / or inner surface of the second hollow cylinder) to its mass or volume, thereby ensuring highly efficient heat exchange with the hollow structure.

[0017] A further development of the thermoelastic energy converter system provides that the two hollow cylinders are arranged around the same central axis, with the hollow structure penetrating the top plate and / or the bottom plate. In other words, the hollow structure or the second hollow cylinder is arranged in the chamber, i.e., the cavity of the first hollow cylinder, such that the two central axes of the two hollow cylinders coincide. The second hollow cylinder or the hollow structure can extend through the bottom plate or the top plate at least into the chamber, or be connected to a plate opposite the penetration along the central axis, or be arranged penetrating both plates within the chamber.Due to the rotationally symmetrical arrangement of the two hollow cylinders around their common central axis, a particularly uniform stress distribution is advantageously achieved under any respective tensile and / or compressive load, for example by compressing at least one of the two components, while simultaneously resulting in a particularly compact or space-saving design of the thermal energy converter or energy converter system.

[0018] A further development of the thermoelastic energy converter system stipulates that the wall thickness of the chamber wall, particularly the top plate and / or bottom plate (when the chamber is designed as a hollow cylinder), is greater in a specified area around each penetration of the hollow structure than in the area affected by the respective penetration. In other words, the chamber wall should be particularly thick in the area around a penetration. Especially when the hollow structure is subjected to pressure from the chamber, gaps between the chamber wall and the hollow structure in the area of ​​each penetration must be avoided to ensure the chamber remains fluidly sealed to the environment. Under pressure, the hollow structure can deform towards a smaller cross-section, particularly a smaller radius in the case of a hollow cylinder design.The thicker the chamber wall in the area of ​​a puncture, the longer the region in which the hollow structure enclosed by the chamber wall is not compressed, and in which a cross-section or radius of the hollow structure expands from its compressed dimensions to its uncompressed dimensions. The wall thickness must be sufficient so that the wall of the hollow structure rests completely against the chamber wall without any gaps before exiting into the surrounding environment. Increasing the wall thickness of the chamber wall only in the specified area around each puncture can result in particularly advantageous weight savings.

[0019] A further development of the thermoelastic energy converter system provides that the pressurization device is configured to subject at least one thermoelastic element to fluid pressure at its natural frequency. In other words, the hollow structure is to be subjected to periodic or time-repeated stress at one of its natural frequencies, one of its resonance frequencies, or a natural fraction thereof, by the fluid pressure in order to excite it to oscillation in one of its natural modes or natural frequencies. The natural frequency is the characteristic frequency of an oscillating system, in this case the hollow structure, at which, once set in motion, it continues to oscillate without further external excitation. The hollow structure can oscillate between a radially or chamber-extended state and a compressed state away from it.The natural frequency here depends on the wall thickness of the hollow structure, its mass, and, via the so-called modulus of elasticity, on its material. By applying pressure at the natural frequency of the hollow structure, its amplitude can be increased with very little energy expenditure, corresponding to its deformation in its maximally expanded and maximally compressed states. This allows for the creation of maximum deformation and thus particularly high temperature extremes with very little loading or excitation energy, depending on the shape-memory material used. Through oscillation of the hollow structure or thermoelastic element, it can deform periodically from a loaded state or first loading state, through the relaxed loading state or unloading state (e.g., an initial position), to a second loading state.This allows at least one temperature extreme to be increased in the manner described, enabling the energy conversion system to be operated particularly efficiently. The intensity of the excitation or the supplied excitation energy, i.e., for example, the duration and magnitude of the fluid pressure, should only be chosen to such an extent that the hollow structure is not destroyed as a result of a so-called "resonance catastrophe".

[0020] A further development of the thermoelastic energy converter system stipulates that the refrigerant circuit includes at least one refrigerant designed to undergo a phase change when absorbing heat from and / or releasing heat to the at least one thermoelastic element. In other words, the refrigerant circuit, or a refrigerant circuit connected or connectable to the energy converter system during its operation, should include at least one refrigerant that evaporates when absorbing heat from the thermoelastic element, thus absorbing heat as enthalpy of vaporization, and / or condenses when releasing heat to the thermoelastic element, thus releasing heat as enthalpy of condensation.This allows for a particularly high heat transfer rate and / or a particularly rapid heat exchange between the refrigerant and the hollow structure, which in turn enables the cycle to operate at a particularly high frequency, ultimately resulting in a particularly high efficiency of the energy conversion system. Until the respective enthalpy or heat is completely absorbed during evaporation or released during condensation, the temperature of a refrigerant that has reached its boiling point remains constant. The convective heat transfer present here depends linearly on the temperature difference between the refrigerant and the thermoelastic element.This temperature difference can therefore be maintained at a particularly high level for a particularly long time, especially longer than with a continuous temperature change (towards the element temperature) of the refrigerant during flow around and / or through the thermoelastic element without a phase change. Specifically, the energy conversion system can comprise two separate refrigerant circuits, each with a different refrigerant, or one refrigerant circuit with two different refrigerants, each of which can be used for heat exchange under different load conditions and / or extreme temperatures of the thermoelastic element. In other words, the system should use a refrigerant optimized for the respective extreme temperature of the thermoelastic element, depending on its load condition.

[0021] A further development of the thermoelastic energy converter system envisages that the hollow structure be made of a shape memory alloy, in particular nickel-titanium, nickel-titanium-copper, iron-manganese-silicon, copper-zinc, copper-zinc-aluminum, copper-aluminum-nickel, and / or iron-nickel-aluminum. In other words, the thermoelastic element or the hollow structure should be made of a shape memory alloy, i.e., a metallic shape memory material, which, as described above, is particularly robust and / or durable, especially in which the thermoelastic or elastocaloric effect is maintained for up to several hundred thousand load cycles.

[0022] In particular, the energy converter system is designed to include several thermoelastic energy converters which can be connected or are connected in parallel with respect to the or a common refrigerant circuit, i.e., are supplied with at least one refrigerant in parallel.

[0023] A second aspect of the invention relates to a thermoelastic energy converter for a thermoelastic energy converter system, particularly according to the first aspect of the invention. Advantages and advantageous developments of the first aspect of the invention are to be regarded as advantages and advantageous developments of the second aspect of the invention, and vice versa.

[0024] The thermoelastic energy converter is characterized by having at least one thermoelastic element as a first component and a chamber wall that at least partially encloses the at least one thermoelastic element, wherein the chamber wall defines a chamber as a second component in which the at least one thermoelastic element is at least partially arranged and the at least one thermoelastic element is designed as a fluidically tight hollow structure relative to the chamber and the hollow structure is arranged to penetrate the chamber wall at at least one point, wherein the hollow structure is fluidically tightly enclosed by the chamber wall at this respective point, and at least one of the two components has at least two fluidically permeable openings and is thus fluidically permeable, and the other component has at least one opening.via which it can be coupled to a pressurization device, by means of which it can be pressurized with a time-varying fluid pressure, by means of which the at least one thermoelastic element can be deformed.

[0025] The invention also includes combinations of the features of the described embodiments. Summary of the characters

[0026] The invention is explained in more detail below using exemplary embodiments and the accompanying figures. The figures show: Fig. 1 A schematic sectional view through a thermoelastic energy converter for a thermoelastic energy converter system, with a fluidically permeable hollow cylinder as the thermoelastic element surrounded by a cylindrical chamber; and Fig. 2 a schematic sectional view through a thermoelastic energy converter for the thermoelastic energy converter system, with a hollow cylinder as a thermoelastic element surrounded by a fluidically permeable and cylindrical chamber. Detailed description of the figures

[0027] The embodiment described below is a preferred embodiment of the invention. In this embodiment, the described components each represent individual features of the invention that can be considered independently of one another. Each of these features further develops the invention independently and can therefore be considered part of the invention individually or in a combination other than that shown. Furthermore, the described embodiment can also be supplemented by other features of the invention already described.

[0028] In the figures, functionally identical elements are each provided with the same reference symbols.

[0029] Fig. Figure 1 shows a schematic sectional view through a thermoelastic energy converter 11 for a thermoelastic energy converter system 10, with a fluid-permeable hollow cylinder as the thermoelastic element 12, surrounded by a cylindrical chamber 14. In the cylindrical chamber 14, which is designed as a first hollow cylinder, the thermoelastic element 12, designed as a second hollow cylinder, can be arranged such that the two cylinders have a common central axis 22. Fig. As shown in Figure 1, the thermoelastic element 12, designed as a hollow structure 13, can penetrate the chamber wall 15 twice, in particular in the area of ​​the cover plate 18 and the base plate 19 that delimit the chamber 14. The hollow structure 13 can have an opening 16 at each of its two ends along the central axis 22, through which the hollow structure 13 can be connected to a refrigerant circuit for heat exchange, so that refrigerant 22 of the refrigerant circuit can flow through it. The chamber wall 15 can have at least one opening 16, in Fig. The chamber 14 has one opening (not shown) in the outer surface 20, the cover plate 18, and / or the base plate 19, through which the chamber 14 can be connected to the pressurization device. Through this at least one opening, the chamber 14 can be pressurized by fluid from the pressurization device, allowing the hollow structure 13 to be pressurized and deformable. If the hollow structure 13 is opened as shown in Fig. As shown in Figure 1, when subjected to pressure, the hollow structure 13 can be compressed in a loading state or initial loading state towards the central axis 22, particularly radially if the hollow structure 13 is designed as a hollow cylinder. Starting from an initial temperature and moving to a depressurized initial state, the hollow structure 13 can heat up by 5–50 °C, for example, from 20 °C to 35 °C. The pressure load can then be maintained until coolant, particularly coolant flowing through the hollow structure 13, has cooled the hollow structure 13 to a predetermined temperature, for example, 20 °C, or until a predetermined mass of coolant has flowed through the thermoelastic energy converter and / or the thermoelastic energy converter system. The pressure in the chamber 14 can then be reduced until it reaches a level equal to the pressure in the hollow structure 13, at which point the hollow structure 13 enters a depressurized state.In this process, the hollow structure 13 can expand radially and cool down to, for example, 5 °C. The unloaded state can be maintained until the hollow structure reaches a predetermined temperature, for example, the initial temperature of 20 °C, or until a predetermined mass flow of coolant has passed through the energy converter 11, in particular the hollow structure 13, and thus supplied heat to the hollow structure 13. With the subsequent reloading, a cycle can begin again.

[0030] Across various examples, refrigerant flows of heated and cooled refrigerant 22 can be directed, for example via a valve of a refrigerant circuit, to different heat exchangers in order to exchange the absorbed or released heat with a consumer and / or the environment. Depending on the load state of the thermoelastic element 12, the refrigerant 22 can also flow in the opposite direction through the refrigerant circuit, in particular through a component, i.e., through the hollow structure 13 and / or the chamber 14. Furthermore, different refrigerants 22 can be used for heat exchange, especially those that can undergo a phase change during the respective heat exchange.In particular, it can be provided that, after the loading state by means of a pressure increase, the two pressures in the chamber 14 and the hollow structure 13 not only equalize to a relief state, but that the overpressure transitions into a relative underpressure, whereby the hollow structure 13 is loaded in a second loading state in the opposite direction to the loading state or first loading state, for example by being in the in . Fig. In the example shown, the hollow structure 13 can expand radially beyond the unloaded state, for example, a temperature extreme of the hollow structure 13 can increase, for example, in this example the low temperature to 0 °C instead of 5 °C only under unloading.

[0031] Fig. 2 shows how Fig. 1 a thermoelastic energy converter for a thermoelastic energy converter system 10 with a hollow structure 13 as a thermoelastic element 12, arranged at least partially in a chamber 14 at least partially bounded by a chamber wall 15. In this example, at least the chamber 14, or the chamber wall 15, can have at least two fluidically flowable openings 16 through which it can be connected to a refrigerant circuit. As in Fig.1. The chamber wall 15 and the hollow structure 13 can be designed as concentric hollow cylinders, wherein at least the hollow structure has at least one opening through which it can be compressed by means of a pressurizing device. By compressing the hollow structure 13, which is designed in particular as a second hollow cylinder, radially from the inside out, its wall can be subjected to tensile stress. Depending on the shape memory material selected for the hollow structure 13, the hollow structure 13 can increase or decrease in size compared to an initial temperature in an unloaded initial state. For heat exchange with the hollow structure 13, the chamber 14 can be supplied with refrigerant 22.Additionally, the hollow structure 13 can have a further opening, and thus at least two openings 16, through which it can be permeated by refrigerant 22 of a separately designed refrigerant circuit, wherein this refrigerant circuit can include a pressurization device. This refrigerant circuit can therefore be different from the one whose refrigerant 22 flows through the chamber 14. The refrigerant circuit connected to the hollow structure 13 can be configured such that the hollow structure 13 is simultaneously pressurized or pressurized by refrigerant 22. Thus, a wall of the hollow structure 13 can be continuously, or in particular during pressurization of the hollow structure 13, surrounded on both sides by refrigerant 22 and thus transfer heat.This allows for a particularly rapid heat exchange with the hollow structure 13, resulting in a particularly high power output or usable power of the thermoelastic energy converter or thermoelastic energy converter system. Overall, the examples shown demonstrate the implementation of a thermoelastic energy converter and a thermoelastic energy converter system with a particularly low required load force for loading the thermoelastic element 12, a particularly low overall weight, and / or a particularly low susceptibility to buckling of the thermoelastic element 12.

[0032] Overall, this example demonstrates how fluidic or hydrostatic loading of shape memory alloys can be provided in elastocaloric applications. Reference symbol list 10 thermoelastic energy converter system 11 thermoelastic energy converter 12 thermoelastic element 13 Hollow structure 14th Chamber 15 chamber wall 16 one of at least two openings 17 that have at least one opening 18 Cover plate 19 Base plate 20 lateral surface area 21 Refrigerants 22 Central axis

Claims

[1] Thermoelastic energy converter system (10) comprising at least one thermoelastic energy converter (11) with at least one thermoelastic element (12) as a first component and a chamber wall (15) at least partially enclosing the at least one thermoelastic element (12), wherein the chamber wall (15) defines a chamber (14) as a second component in which the at least one thermoelastic element (12) is at least partially arranged, characterized by, that the at least one thermoelastic element (12) is designed as a hollow structure (13) fluidically sealed with respect to the chamber (14) and the hollow structure (13) is arranged to penetrate the chamber wall (15) at at least one point, wherein the hollow structure (13) is fluidically tightly enclosed by the chamber wall (15) at this respective point, and at least one of the two components has at least two openings (16) through which fluids can flow and is thus fluidically permeable, and the other component has at least one opening (17) through which it is coupled to a pressure-applying device by means of which it can be pressurized with a time-varying fluid pressure by means of which the at least one thermoelastic element (12) is deformable. [2] Thermoelastic energy converter system (10) according to claim 1, characterized by, that at least one of the two components is coupled to a refrigerant circuit via the at least two fluidically flowable openings (16) in order to absorb heat from and / or transfer heat to the at least one thermoelastic element (12). [3] Thermoelastic energy converter system (10) according to any one of the preceding claims, characterized by , that the chamber (14) is designed as a first hollow cylinder, wherein the chamber wall (15) has a lateral surface of the first hollow cylinder, a cover plate (18) and a bottom plate (19) arranged opposite the cover plate (18) along a central axis (22) of the first hollow cylinder. [4] Thermoelastic energy converter system (10) according to any one of the preceding claims, characterized by , that the hollow structure (13) is designed as a second hollow cylinder. [5] Thermoelastic energy converter system (10) according to claims 3 and 4, characterized by, that the two hollow cylinders are arranged around the same central axis (22), wherein the hollow structure (13) is arranged to pierce the top plate (18) and / or the bottom plate (19). [6] Thermoelastic energy converter system (10) according to any one of the preceding claims, characterized by , that the wall thickness of the chamber wall (15) in a given area around a respective penetration of the hollow structure (13) is higher than in a respective area spaced away from the respective penetration. [7] Thermoelastic energy converter system (10) according to any one of the preceding claims, characterized by , that the pressurization device is configured to apply the time-varying fluid pressure to the at least one thermoelastic element (12) at its natural frequency. [8] Thermoelastic energy converter system (10) according to one of the preceding claims in conjunction with claim 2, characterized by, that the refrigerant circuit includes at least one refrigerant (21) which is designed to undergo a phase change when it absorbs heat from and / or releases heat to the at least one thermoelastic element (12). [9] Thermoelastic energy converter system (10) according to any one of the preceding claims, characterized by , that the hollow structure (13) is made of a shape memory alloy, in particular nickel-titanium, nickel-titanium-copper, iron-manganese-silicon, copper-zinc, copper-zinc-aluminium, copper-aluminium-nickel and / or iron-nickel-aluminium. [10] Thermoelastic energy converter (11) for a thermoelastic energy converter system (10) according to one of the preceding claims, characterized by, that the thermoelastic energy converter (11) comprises at least one thermoelastic element (12) as a first component and a chamber wall (15) at least partially enclosing the at least one thermoelastic element (12), wherein the chamber wall (15) delimits a chamber (14) as a second component in which the at least one thermoelastic element (12) is at least partially arranged and the at least one thermoelastic element (12) is designed as a fluidically tight hollow structure (13) relative to the chamber (14) and the hollow structure (13) is arranged to penetrate the chamber wall (15) at at least one point, wherein the hollow structure (13) is fluidically tightly enclosed by the chamber wall (15) at this respective point, and at least one of the two components has at least two fluidically permeable openings (16) and is thus fluidically permeable and the other component has at least one opening (17),via which it can be coupled to a pressurization device, by means of which it can be pressurized with a time-varying fluid pressure, by means of which the at least one thermoelastic element (12) can be deformed.

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