Thermal energy storage system and thermal energy storage method

Abstract

To provide technology that shortens the time required to store thermal energy. [Solution] The heat storage system of the present invention comprises a chamber having a containment space extending in a predetermined direction, a phase change material filled in the containment space, a magnetic field generating unit that generates a magnetic field directed from one end to the other of the containment space, and a heat exchange unit that heats the chamber from the other end of the containment space to perform heat exchange with the phase change material, thereby melting the phase change material which is in a solid phase within the containment space, wherein the phase change material is composed of a thermosensitive magnetic fluid that can change between a liquid phase and a solid phase depending on the temperature.

Description

Technical Field

[0001] The present invention relates to a heat storage system used for storing thermal energy.

Background Art

[0002] Conventionally, a heat storage system used for storing thermal energy has been known. For example, it has a configuration in which a phase change material is filled and sealed in a storage container (see Patent Document 1). The phase change material stores thermal energy by absorbing heat accompanying the change from the solid phase to the liquid phase, and releases thermal energy by radiating heat accompanying the change from the liquid phase to the solid phase. Therefore, with this configuration, thermal energy can be stored by the phase change material filled in the storage container.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above configuration, there is a problem that a corresponding time is required for the change from the solid phase to the liquid phase, that is, to melt the phase change material and store thermal energy. This problem becomes more prominent as the volume of the storage container increases, and thus a solution is sought. The present invention has been made to solve such problems, and its object is to provide a technique for shortening the time for storing thermal energy.

Means for Solving the Problems

[0005] To solve the above problems, a heat storage system according to a first aspect includes a chamber having a storage space extending in a predetermined direction, a phase change material filled in the storage space, a magnetic field generating unit that generates a magnetic field from one end to the other end of the storage space, and a heat exchange unit that heats the chamber from the other end side of the storage space to perform heat exchange with the phase change material, thereby melting the phase change material that is in a solid phase in the storage space. The phase change material is a thermosensitive magnetic fluid that can change between a liquid phase and a solid phase according to temperature, and it is a heat storage system.

[0006] In the heat storage system of this aspect, when the phase change material is in a solid phase in the storage space, by heating the storage space from the other end side of the chamber, the phase change material in this storage space melts from the other end side and changes into a liquid phase. The thus melted liquid-phase phase change material is caused to convection in the storage space under the influence of a magnetic field that travels from one end to the other end of the storage space. This is because the higher the temperature of the phase change material at the other end side of the storage space, the smaller the magnetic body force F1 acting here, and the magnetic body force F2 acting on the phase change material far from the other end of the storage space is more dominant (F1 < F2). As a result, this phase change material tries to move from the one end side to the other end side.

[0007] Thus, by causing the phase change material to convection in the storage space, the melting of the phase change material is promoted from the other end side to the one end side. As a result, the time required to store thermal energy can be shortened. The larger the volume of the storage space, the more effectively the melting due to the convection of the phase change material is promoted, and the effect of shortening the time required for the melting of the entire phase change material is higher compared to the case without convection.

[0008] To solve the above problems, the heat storage system according to the second aspect includes a chamber having an accommodation space extending in a predetermined direction, a phase change material filled in the accommodation space, a magnetic field generation unit that generates a magnetic field from one end to the other end of the accommodation space, and a heat exchange unit that cools the chamber from one end side of the accommodation space to perform heat exchange with the phase change material, thereby solidifying the phase change material that is in a liquid phase in the accommodation space. The phase change material is a heat-sensitive magnetic fluid that can change between a liquid phase and a solid phase according to temperature, and it is a heat storage system.

[0009] In the heat storage system according to the second aspect, when the phase change material is in a liquid phase in the accommodation space, by cooling the accommodation space from one end side of the chamber, the phase change material in this accommodation space solidifies from one end side and changes to a solid phase. At this time, the liquid-phase phase change material on the other end side is affected by the magnetic field from one end to the other end of the accommodation space and starts to convection in the accommodation space. This is because the higher the temperature of the phase change material on the other end side of the accommodation space, the smaller the magnetic body force F1 acting here, and the magnetic body force F2 acting on the phase change material far from the other end of the accommodation space is more dominant (F1 < F2), so this phase change material tries to move from one end side to the other end side.

[0010] In this way, by causing the phase change material to convection in the accommodation space, the solidification of the phase change material from one end side to the other end side is promoted, and as a result, the time required to store thermal energy can be shortened. The larger the volume of the accommodation space, the more effectively the solidification due to the convection of the phase change material is promoted, and the effect of shortening the time required for the solidification of the entire phase change material is higher compared to the case without convection.

[0011] Each of the above aspects may be as follows in the third aspect. In the third aspect, the magnetic field generation unit is an electromagnet disposed on the other end side of the accommodation space.

[0012] For the heat storage system of this aspect, by controlling the operation of the electromagnet, which is the magnetic field generation unit, a magnetic field can be generated at a desired timing.

[0013] Furthermore, this phase may be as shown in the fourth phase below. In the fourth phase, the system includes a control unit that initiates heat exchange by the heat exchange unit and initiates the generation of a magnetic field by the magnetic field generating unit.

[0014] In this type of heat storage system, by controlling the operation of the heat exchange section and the magnetic field generation section, the phase change material can be convected within the containment space at a desired timing.

[0015] Each of the above phases may be as shown in the fifth phase below. In the fifth phase, the phase change material is composed of a water-based magnetic fluid.

[0016] Furthermore, in order to solve the above problems, the sixth heat storage method is a heat storage system comprising a chamber having a containment space extending in a predetermined direction, a phase change material filled in the containment space, and a magnetic field generating unit that generates a magnetic field directed from one end to the other of the containment space, wherein the phase change material is a thermosensitive magnetic fluid that can change between a liquid phase and a solid phase depending on the temperature, and the heat storage method is a method in which the phase change material, which is in a solid phase in the containment space, is melted by heating the chamber from the other end of the containment space.

[0017] Furthermore, in order to solve the above problems, the seventh heat storage method comprises a chamber having a containment space extending in a predetermined direction, a phase change material filled in the containment space, and a magnetic field generating unit that generates a magnetic field directed from one end to the other of the containment space, wherein the phase change material is a thermosensitive magnetic fluid that can change between a liquid phase and a solid phase depending on the temperature, and the heat storage method involves cooling the chamber from one end of the containment space to solidify the phase change material which is in the liquid phase within the containment space. [Brief explanation of the drawing]

[0018] [Figure 1] A diagram showing the structure of a thermal storage system, which is an embodiment of the disclosure. [Figure 2]Diagram showing the process of phase change of the phase change material in the heat storage system according to an embodiment of the present disclosure

Mode for Carrying Out the Invention

[0019] Embodiments of the present invention will be described below with reference to the drawings. (1) Overall Configuration

[0020] As shown in FIG. 1, the heat storage system 1 includes a chamber 10 having a housing space 11 extending in a predetermined direction (in this embodiment, from bottom to top), a phase change material 20 filled in the housing space 11, a magnetic field generation unit 30 that generates a magnetic field in the housing space 11, a heat exchange unit 40 that performs heat exchange with the chamber 10, and a control unit 50 that controls the operation of the entire heat storage system 1.

[0021] The chamber 10 is a cylindrical member extending in a predetermined direction, and its partition wall surrounds the housing space 11.

[0022] The phase change material 20 is composed of a temperature-sensitive magnetic fluid that can change between a liquid phase and a solid phase according to temperature. In this embodiment, a water-based magnetic fluid is adopted as the phase change material 20.

[0023] The magnetic field generation unit 30 generates a magnetic field that travels from one end to the other end of the housing space 11 (in this embodiment, from the lower end to the upper end) (see arrow a in FIG. 2). In this embodiment, an electromagnet arranged on the other end face of the chamber 10 is adopted as the magnetic field generation unit 30. This electromagnet operates in response to a command from the control unit 50.

[0024] The heat exchange unit 40 includes a first heat exchange unit 41 that heats the chamber 10 from the other end side of the housing space 11, and a second heat exchange unit 43 that cools the chamber 10 from the one end side of the housing space 11.

[0025] The first heat exchange unit 41 melts the phase change material 20, which is in a solid state within the containment space 11, by heating the chamber 10 from the other end of the containment space 11. In this embodiment, a sheet-shaped heater arranged along the other end surface of the chamber 10 is used as the first heat exchange unit 41. This first heat exchange unit 41 is positioned between the other end surface of the chamber 10 and the magnetic field generating unit 30. This first heat exchange unit 41 operates in response to commands from the control unit 50.

[0026] The second heat exchange unit 43 solidifies the phase-change material 20, which is in the liquid phase within the containment space 11, by cooling the chamber 10 from one end of the containment space 11. In this embodiment, a chiller arranged along the other end face of the chamber 10 is used as the second heat exchange unit 43. The heat exchanger component of this second heat exchange unit 43 is arranged along one end face of the chamber 10. This second heat exchange unit 43 operates in response to commands from the control unit 50.

[0027] The control unit 50 receives a command from the user via a user interface (not shown) and starts heat exchange by the heat exchange unit 40, as well as starting magnetic field generation by the magnetic field generation unit 30.

[0028] (2) Variant Although embodiments of the present invention have been described above, it goes without saying that the present invention is not limited in any way to the above embodiments and can take various forms as long as they fall within the technical scope of the present invention.

[0029] For example, in the above embodiment, a configuration was shown in which the magnetic field generating unit 30 and the first heat exchange unit 41 are arranged on the upper end side of the chamber 10. However, the magnetic field generating unit 30 and the first heat exchange unit 41 may be arranged on the lower end side, as long as they can heat the other end and generate a magnetic field that flows from one end to the other.

[0030] In addition, in the above embodiment, a configuration in which an electromagnet is adopted as the magnetic field generation unit 30 is illustrated. However, as long as the magnetic field generation unit 30 can generate a magnetic field from one end to the other end of the accommodation space 11, a configuration adopting a permanent magnet or the like may be used.

[0031] In addition, in the above embodiment, a configuration in which the first heat exchange unit 41 is a heater arranged along the other end face of the chamber 10 is illustrated. However, the first heat exchange unit 41 may be configured to be arranged so as to surround the side surface on the other end side of the chamber 10.

[0032] In addition, in the above embodiment, a configuration in which the phase change material 20 adopts a water-based magnetic fluid is illustrated. However, as the phase change material 20, a configuration adopting an oil-based or solvent-based magnetic fluid may be used.

[0033] In addition, in the above embodiment, a configuration in which the magnetic field generation unit 30 is arranged on the other end face of the chamber 10 is illustrated. However, this magnetic field generation unit 30 only needs to be arranged on the other end side of the accommodation space 11 in the chamber 10, and a configuration in which a part or all of it is arranged inside the accommodation space 11 may be used.

[0034] (3) Operation, Effect In the heat storage system 1 of the above embodiment, when the phase change material 20 is in a solid phase in the accommodation space 11, by heating the accommodation space 11 from the other end side of the chamber 10, the phase change material 20 in this accommodation space 11 melts from the other end side and changes to a liquid phase. The thus melted liquid-phase phase change material 20 is affected by the magnetic field from one end to the other end of the accommodation space 11 and starts to convection in the accommodation space 11.

[0035] This is because the higher the temperature of the phase change material 20 at the other end side of the accommodation space 11, the smaller the magnetic body force F1 acting here, and the magnetic body force F2 acting on the phase change material 20 far from the other end of the accommodation space 11 is more dominant (F1 < F2). As a result, this phase change material 20 tends to move from the one end side to the other end side.

[0036] Thus, by causing the phase change material 20 to flow in the accommodation space 11, the melting of the phase change material 20 is promoted from the other end side toward the one end side, and the phase change material 20 (21) that was in the solid phase is gradually melted, and the liquid-phase phase change material 20 (23) increases on the other end side of the accommodation space 11 (Figs. 2(a) to 2(d)). As a result, the time for storing thermal energy can be shortened. The larger the volume of the accommodation space 11 is, the more effectively the melting of the phase change material 20 due to convection is promoted, and the higher the effect of shortening the time required for melting the entire phase change material 20 is as compared with the case where there is no convection.

[0037] Further, in the heat storage system 1 of the above embodiment, when the phase change material 20 is in the liquid phase in the accommodation space 11, by cooling the accommodation space 11 from one end side of the chamber 10, the phase change material 20 in this accommodation space 11 solidifies from the one end side and changes to the solid phase. At this time, the liquid-phase phase change material 20 on the other end side is affected by the magnetic field that travels from one end of the accommodation space 11 to the other end and starts to flow in the accommodation space 11.

[0038] Further, in the heat storage system 1 of the above embodiment, when the phase change material 20 is in the liquid phase in the accommodation space 11, by cooling the accommodation space 11 from one end side of the chamber 10, the phase change material 20 in this accommodation space 11 solidifies from the one end side and changes to the solid phase. At this time, the liquid-phase phase change material 20 on the other end side is affected by the magnetic field that travels from one end of the accommodation space 11 to the other end and starts to flow in the accommodation space 11.

[0039] This is because the higher the temperature of the phase change material 20 is at the other end side of the accommodation space 11, the smaller the magnetic body force F1 acting here becomes, and the magnetic body force F2 acting on the phase change material farther from the other end of the accommodation space 11 is more dominant (F1 < F2), and as a result, this phase change material tries to move from the one end side to the other end side.

[0040] In this way, by causing convection of the phase-change material 20 within the containment space 11, the solidification of the phase-change material 20 is promoted from one end to the other. The liquid phase of the phase-change material 20 gradually solidifies at one end, and the solid phase of the phase-change material 20 spreads to the other end of the containment space 11. As a result, the time required to store thermal energy can be shortened. The larger the volume of the containment space 11, the more effectively the solidification of the phase-change material 20 by convection is promoted, and the greater the effect of shortening the time required for the solidification of the entire phase-change material 20 compared to when there is no convection.

[0041] Furthermore, with the heat storage system 1 of the above embodiment, a magnetic field can be generated at a desired timing by controlling the operation of the electromagnet, which is the magnetic field generating unit 30.

[0042] Furthermore, with the heat storage system 1 of the above embodiment, the phase change material 20 can be convection within the containment space 11 at a desired timing by controlling the operation of the heat exchange unit 40 and the magnetic field generating unit 30. [Explanation of Symbols]

[0043] 1…Heat storage system, 10…Chamber, 11…Accommodation space, 20…Phase change material, 21…Solid phase change material, 23…Liquid phase change material, 30…Magnetic field generation unit, 40…Heating unit, 41…First heat exchange unit, 43…Second heat exchange unit, 50…Control unit

Claims

1. A chamber having a containment space extending in a predetermined direction, The phase change material that fills the aforementioned containment space, A magnetic field generating unit that generates a magnetic field extending from one end to the other of the aforementioned containment space, The system includes a heat exchange section that heats the chamber from the other end of the containment space to perform heat exchange with the phase change material, thereby melting the phase change material which is in a solid state within the containment space. The phase-change material is composed of a temperature-sensitive magnetic fluid that can change between a liquid phase and a solid phase depending on the temperature. Thermal energy storage system.

2. A chamber having a containment space extending in a predetermined direction, The phase change material that fills the aforementioned containment space, A magnetic field generating unit that generates a magnetic field extending from one end to the other of the aforementioned containment space, The system includes a heat exchange section that cools the chamber from one end of the containment space and performs heat exchange with the phase change material, thereby solidifying the phase change material which is in the liquid phase within the containment space. The phase-change material is composed of a temperature-sensitive magnetic fluid that can change between a liquid phase and a solid phase depending on the temperature. Thermal energy storage system.

3. The magnetic field generating unit is an electromagnet located on the other end side of the housing space. A heat storage system according to claim 1 or claim 2.

4. The system includes a control unit that initiates heat exchange by the heat exchange unit and initiates the generation of a magnetic field by the magnetic field generating unit. The heat storage system according to claim 3.

5. The aforementioned phase change material is composed of a water-based magnetic fluid. The heat storage system according to claim 1.

6. A chamber having a containment space extending in a predetermined direction, The phase change material that fills the aforementioned containment space, A magnetic field generating unit that generates a magnetic field extending from one end to the other of the aforementioned containment space, Equipped with, In a heat storage system in which the phase change material is a temperature-sensitive magnetic fluid that can change between a liquid phase and a solid phase depending on the temperature, A heat storage method comprising heating the chamber from the other end of the containment space to melt the phase change material which is in a solid phase within the containment space.

7. A chamber having a containment space extending in a predetermined direction, The phase change material that fills the aforementioned containment space, A magnetic field generating unit that generates a magnetic field extending from one end to the other of the aforementioned containment space, Equipped with, In a heat storage system in which the phase change material is a temperature-sensitive magnetic fluid that can change between a liquid phase and a solid phase depending on the temperature, A heat storage method comprising solidifying the phase-change material, which is in the liquid phase within the containment space, by cooling the chamber from one end of the containment space.

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