EP2956519A1 - Matériau composite pour accumulateur d'énergie thermique et procédé de fabrication d'un matériau composite pour accumulateur d'énergie thermique - Google Patents

Matériau composite pour accumulateur d'énergie thermique et procédé de fabrication d'un matériau composite pour accumulateur d'énergie thermique

Info

Publication number
EP2956519A1
EP2956519A1 EP14709205.0A EP14709205A EP2956519A1 EP 2956519 A1 EP2956519 A1 EP 2956519A1 EP 14709205 A EP14709205 A EP 14709205A EP 2956519 A1 EP2956519 A1 EP 2956519A1
Authority
EP
European Patent Office
Prior art keywords
composite material
phase change
change material
composite
crystallization nuclei
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP14709205.0A
Other languages
German (de)
English (en)
Inventor
Jochen SCHÄFER
Christian Seidel
Christian Triebel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens AG
Original Assignee
Siemens AG
Siemens Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens AG, Siemens Corp filed Critical Siemens AG
Publication of EP2956519A1 publication Critical patent/EP2956519A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
    • C09K5/02—Materials undergoing a change of physical state when used
    • C09K5/06—Materials undergoing a change of physical state when used the change of state being from liquid to solid or vice versa
    • C09K5/063—Materials absorbing or liberating heat during crystallisation; Heat storage materials
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F110/00—Homopolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
    • C08F110/02—Ethene

Definitions

  • the invention relates to a composite material for a thermal energy storage and a method for producing such a composite material for a thermal energy storage.
  • Formed latent heat storage use the properties of phase change materials whose latent heat of fusion, solution heat or heat of absorption is much greater than the heat they can save due to their normal specific heat capacity without the phase transformation effect.
  • Application examples are e.g. Heat pads, cooling batteries or paraffin-filled storage elements in the tanks of solar thermal systems.
  • the undesired phenomenon of subcooling can occur, as a result of which the crystallization of the phase change material and thus the heat emission only begin significantly below the melting point of the phase change material.
  • the heat output is at a relatively low temperature level, which may be unfavorable for use in an energy storage.
  • phase change materials that are in focus here, which despite a phase change from solid to liquid have a relatively dimensionally stable behavior, such as ultra high molecular weight polyethylene, which due to its chain lengths of the molecules has a viscosity which has a certain dimensional stability even after a phase change from solid to liquid brings with it.
  • the composite material according to the invention for a thermal energy store comprises a thermoplastic phase change material in which crystallization nuclei are embedded with a predetermined spatial distribution. Due to the fact that the composite material contains the crystallization nuclei in addition to the thermoplastic phase change material, the unwanted phenomenon of supercooling can be considerably reduced since, starting from the crystallization nuclei, solidification of the phase change material takes place substantially immediately after the melting point of the phase change material has fallen below. Along with the solidification or the crystallization of the phase change material thus also relevant for use in a thermal energy storage heat dissipation sets substantially immediately below the melting point of the phase change material. The heat release can thus take place at a relatively high temperature level, which is advantageous in view of the application of the composite material in a thermal energy storage.
  • the phase change material is an ultra high molecular weight polyethylene. This has the advantage that Because of the chain lengths of the molecules of the phase change material, the phase change material, and thus the composite as a whole, has such a viscosity during a phase change from solid to liquid that a certain shape stability of the composite still exists.
  • the phase change material preferably has a zero viscosity above its melting temperature of at least one kilopascal second, preferably one megapascal second.
  • the crystallization nuclei have a higher softening temperature, in particular an at least 50 ° C higher softening temperature, as the phase change material.
  • the melting temperature of the phase change material is preferably about 130 ° C, but may also in a range of about 100 to 170 ° C, depending on the composition of the phase change material, move.
  • a further advantageous embodiment of the invention provides that the crystallization nuclei have a higher thermal conductivity than the phase change material.
  • the crystallization nuclei are fibrous materials made of carbon, such as carbon fibers, carbon nanotubes and the like, platelet-shaped materials, for example, from talc, graphite or phyllosilicates, and / or both on the micro and nanometer scale spherically formed materials, such as boron nitride, silica or carbon black, are.
  • a further advantageous embodiment of the invention provides that by means of the crystallization nuclei at least one predetermined heat conduction path is formed within the composite material, which has a higher thermal conductivity than the rest of the composite material in at least one direction.
  • an anisotropic thermal conductivity of the composite material may be formed so that, for example, a particularly good heat absorption and heat dissipation can take place in a preferred direction, so that a corresponding adaptation of the composite material to respective boundary conditions when used in a thermal energy store can be made possible
  • the crystallization nuclei are arranged within the composite material such that it has an at least substantially isotropic thermal conductivity. In this case, the nuclei are preferably distributed substantially uniformly within the composite.
  • the number of crystallization nuclei decreases from the outer edge regions of the composite material to the inner regions of the composite material.
  • the outer edge regions over which usually a heat input as well as a heat dissipation of the composite material when used in a thermal energy storage can absorb and release heat energy particularly well.
  • a particularly fast response of the composite material can be achieved when the melting temperature of the phase change material is exceeded or fallen short of.
  • thermoplastic phase change material is mixed with crystallization seeds to form a mixture, from which the composite material is subsequently formed.
  • Advantageous embodiments of the composite material according to the invention are to be regarded as advantageous embodiments of the method.
  • the crystallization nuclei and the thermoplastic phase change material are mixed together in a powdery state. This allows a particularly good and simple mixing of the crystal nuclei with the phase change material.
  • phase change material prior to mixing with the crystallization germs with a solvent, in particular with an organic solvent, mixed and after mixing the phase change material with the nuclei of the solvent is removed from the mixture ,
  • a solvent in particular with an organic solvent
  • Phase change material as well as the possibility of shaping a casting process.
  • a further advantageous embodiment of the method provides that the mixture is extruded or pressed, in particular hot-pressed, into the composite material.
  • the viscosity of the phase change material used one or the other method is more appropriate.
  • the viscosity of the phase change material used should not be too high above its melting temperature, in particular in the range of 1,000 to 10,000 Pascal seconds, the composite material of the desired quality can be produced by means of extrusion.
  • a viscosity of the phase change terials of more than 10,000 Pascal seconds is especially a hot pressing process to produce the composite, since a promotion of the mixture by means of extrusion is difficult or not feasible.
  • this is evacuated during the pressing process, in order to reduce or reduce the molded part porosity.
  • FIG. 1 shows a schematic representation of a composite material for a thermal energy store, which is made of a thermoplastic Phasen Touchmate- rial, in which a plurality of crystallization nuclei is embedded; and
  • FIG. 2 shows a schematic representation of a
  • a composite material designated as a whole by 10 for a thermal energy store (not shown here) is shown in a schematic representation in FIG.
  • the composite material comprises a thermoplastic phase change material 12, into which a multiplicity of crystallization particles 14 are embedded, wherein only a part of the crystallization seeds 14 is provided with a reference numeral.
  • the phase change material 12 is an ultrahigh molecular weight polyethylene having an average molecular weight of up to 6,000 kg / mol and a density of 0.89 to
  • the phase change material 12 has a zero viscosity of at least one kilopascal second, preferably a megapascal second, above its melting temperature.
  • Phase change material is about 130 ° C, and depending on the composition of the phase change material 12 also melting temperatures in the range of about 100 to 170 ° C may be present.
  • the crystallization nuclei 14 may be made, for example, of fibrous materials consisting of carbon (eg carbon fibers, carbon nanotubes, etc.), of platelet-shaped materials such as talc, graphite and phyllosilicates or of spherical materials, both on a micro and a nanometer scale, such as boron nitride , Silicon dioxide and carbon black.
  • the crystallization nuclei 14 preferably have a higher softening temperature than the phase change material 12.
  • the softening temperature of the crystallization nuclei 14 may be, for example, about 50 ° above the melting temperature of the phase change material 12, so that within the usually provided operating temperatures of the composite material 10 in a thermal energy storage, the crystallization nuclei 14 do not melt and thus remain mechanically and geometrically stable and also inert to the phase change material 12 behave.
  • the crystallization nuclei 12 preferably also have a higher thermal conductivity than the phase change material 12. As a result, an increase in the effective thermal conductivity of the entire composite material 10 can be achieved.
  • the crystallization nuclei 14 may, as shown here, be arranged substantially uniformly within the composite material 10 or within the phase change material 12 serving as matrix material. With such a uniform distribution of the crystallization nuclei 14, an isotropic heat conduction behavior of the composite material 10 usually results.
  • the crystallization nuclei 14 may also be disposed unevenly within the composite material 10 contrary to the illustration shown here.
  • the number of crystallization seeds 14 may decrease inwardly from an outer edge region which is schematically separated from an inner region of the composite material 10 by the dashed line 16.
  • the crystallization nuclei 14 it is thus possible for the crystallization nuclei 14 to be arranged in outer regions of the composite material 10 with a higher concentration than within the inner regions of the composite material 10. Thereby, the heat absorption and the heat release behavior of the composite material 10 can be adjusted accordingly.
  • a correspondingly predetermined heat conduction path within the composite material 10 may be formed within the composite material 10 by a corresponding arrangement of the crystallization nuclei 14.
  • preferred directions for the heat conduction within the composite material 10 in the horizontal direction x, in the vertical direction y or orthogonal to the plane defined by the horizontal direction x and the vertical direction y can be set.
  • the composite material 10 has a higher thermal conductivity in at least one direction than the remaining composite material 10 in these cases.
  • the phase change material 12 has a zero viscosity of at least one kilopascal second, preferably one megapascal second, above its melting temperature. has, even after a phase change from solid to liquid can be ensured that the nuclei 14 remain substantially at their predetermined location within the composite material 10. In other words, therefore, a drop or even a flooding of the crystallization nuclei 14 is prevented by the correspondingly high viscosity of the phase change material 12, even above its melting temperature. Due to the cycle-stable spatial arrangement of the crystallization nuclei 14, the phase change material 12 has a reproducible crystallization behavior over a plurality of thermal cycles.
  • FIG. 2 shows, in a schematic side view, an extruder 18 by means of which the composite material 10 is produced.
  • the phase change material 12 which is supplied in powder form to the extruder 18, is shown schematically by means of the circles.
  • the nuclei 14 and the phase change thermoplastic material 12 are supplied to a hopper 20 in a powdery state. In the hopper 20, the nuclei 14 and the phase change material 12 are mixed together to form a mixture 22.
  • the mixing or mixing of the crystallization nuclei 14 and the thermoplastic phase change material 12 takes place in such a way that the crystallization nuclei 14 are distributed as homogeneously as possible within the phase change material 12.
  • the mixture 22 is fed to a screw 24 of the extruder 18, wherein the screw 24 is guided within a cylinder 26 of the extruder 18.
  • the cylinder 26 can be heated over its length on the one hand, but also be cooled to the other in order to operate the extrusion of the mixture 22 as desired.
  • the extrusion process shown here for the production of the composite material 10 is particularly suitable when, on the one hand, a particularly homogeneous arrangement of the crystallization nuclei 14 within the phase change material 12 is desired and, on the other hand, if the viscosity of the phase change material 12 should not be too high, in particular in a range between 1,000 and 10,000 Pascal seconds.
  • phase change material 12 which is used to produce the composite material 10
  • phase change material 12 have a relatively high viscosity, in particular in the range of more than 10,000 pascal seconds
  • a pressing process in particular a hot pressing process, is more suitable instead of the extrusion process.
  • the phase change material 12 and the crystallization nuclei 14 are initially mixed in powder form to form the mixture 22 and then fed to a suitable press for producing the composite material.
  • different mixtures 22 can each be produced and arranged or heaped up, for example, by a corresponding layering within a hot pressing tool.
  • the phase change material 12 before mixing with the crystallization nuclei 14 first with a solvent, in particular with an organic solvent, for example in the form of 1, 2, 4 -Trichlorbenzol at a temperature of 135 ° C, is mixed. Subsequently, the phase change material 12 is mixed with the crystallization seeds 14, wherein after mixing, the solvent is removed again from the mixture 22 produced.
  • the mixture 22 can in turn optionally the one shown
  • Extrusion process or the already mentioned Pressg. Hot pressing process can be supplied.
  • the mixture 22 may be evacuated during the pressing operation until the composite material 10 has a predetermined porosity.
  • a vacuuming can be carried out within a pressing tool in order to remove excess or undesired air from the composite material 10.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Thermal Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Combustion & Propulsion (AREA)
  • Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Extrusion Moulding Of Plastics Or The Like (AREA)

Abstract

L'invention concerne un matériau composite (10) destiné à un accumulateur d'énergie thermique, comprenant un matériau thermoplastique à changement de phase (12) dans lequel des germes de cristallisation (14) sont noyés selon une distribution spatiale prédéfinie. L'invention concerne en outre un procédé de fabrication d'un matériau composite (10) destiné à un accumulateur d'énergie thermique.
EP14709205.0A 2013-03-18 2014-02-19 Matériau composite pour accumulateur d'énergie thermique et procédé de fabrication d'un matériau composite pour accumulateur d'énergie thermique Withdrawn EP2956519A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102013204690.1A DE102013204690A1 (de) 2013-03-18 2013-03-18 Verbundwerkstoff für einen thermischen Energiespeicher und Verfahren zum Herstellen eines Verbundwerkstoffs für einen thermischen Energiespeicher
PCT/EP2014/053178 WO2014146844A1 (fr) 2013-03-18 2014-02-19 Matériau composite pour accumulateur d'énergie thermique et procédé de fabrication d'un matériau composite pour accumulateur d'énergie thermique

Publications (1)

Publication Number Publication Date
EP2956519A1 true EP2956519A1 (fr) 2015-12-23

Family

ID=50241375

Family Applications (1)

Application Number Title Priority Date Filing Date
EP14709205.0A Withdrawn EP2956519A1 (fr) 2013-03-18 2014-02-19 Matériau composite pour accumulateur d'énergie thermique et procédé de fabrication d'un matériau composite pour accumulateur d'énergie thermique

Country Status (5)

Country Link
EP (1) EP2956519A1 (fr)
CN (1) CN105189693A (fr)
DE (1) DE102013204690A1 (fr)
RU (1) RU2620843C2 (fr)
WO (1) WO2014146844A1 (fr)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3139123B1 (fr) * 2015-09-02 2018-01-10 H.M. Heizkörper GmbH & Co. KG Accumulateur de chaleur latente dote d'un dispositif de declenchement de la cristallisation dans un materiau a changement de phase et procede de declenchement de la cristallisation dans un materiau a changement de phase
CN108759536A (zh) * 2018-06-29 2018-11-06 丁玉龙 储能装置
CN108750396B (zh) * 2018-06-29 2020-11-03 丁玉龙 保温运输系统
CN115181551B (zh) * 2022-07-07 2023-12-12 深圳市鸿富诚新材料股份有限公司 一种各向异性导热相变材料及其制备方法

Citations (2)

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US4487856A (en) * 1983-03-14 1984-12-11 E. I. Du Pont De Nemours And Company Ethylene polymer composite heat storage material
US20100301258A1 (en) * 2007-05-07 2010-12-02 Massachusetts Institute of Technolohy Polymer sheets and other bodies having oriented chains and method and apparatus for producing same

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JPS5776078A (en) * 1980-10-29 1982-05-12 Agency Of Ind Science & Technol Heat accumulator utilizing latent heat
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EP0481564B1 (fr) * 1990-10-15 1995-01-25 Matsushita Electric Works, Ltd. Accumulateur de chaleur contenant de la matière huileuse et procédé de sa fabrication
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US20100301258A1 (en) * 2007-05-07 2010-12-02 Massachusetts Institute of Technolohy Polymer sheets and other bodies having oriented chains and method and apparatus for producing same

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See also references of WO2014146844A1 *

Also Published As

Publication number Publication date
RU2015144589A (ru) 2017-04-24
WO2014146844A1 (fr) 2014-09-25
RU2620843C2 (ru) 2017-05-30
DE102013204690A1 (de) 2014-09-18
CN105189693A (zh) 2015-12-23

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