Heat storage device

Abstract

To provide a heat storage device advantageous for sufficiently melting a latent heat storage material in a short time.SOLUTION: A heat storage device 1a comprises a shell 10, a latent heat storage material 20, a plurality of heat transfer pipes 30, and a melting assistance mechanism 40. The shell 10 comprises an internal space including a first space 11, a second space 12, and a third space 13. The first space 11, the second space 12, and the third space 13 are arranged along a reference plane. The latent heat storage material 20 is housed in the third space 13. The plurality of heat transfer pipes 30 comprise outer surfaces 31 in contact with the third space 13. The plurality of heat transfer pipes 30 cause the first space 11 and the second space 12 to communicate with each other. The melting assistance mechanism 40 assists melting of the latent heat storage material 20 in a central part 25c of a bottom part 25 of the third space 13 when the latent heat storage material 20 is melted by heat dissipation from a heat medium passing through the inside of the plurality of heat transfer pipes 30 from the first space 11 to the second space 12.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a thermal storage device. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a heat storage device using a latent heat storage material is known.

[0003] For example, Patent Document 1 describes a heat storage device in which multiple tubes are arranged horizontally in multiple stages inside a shell. A latent heat storage material is accommodated inside the shell. A heat transfer fluid flows through the inside of the tube, and heat from the outside is provided to the latent heat storage material, or heat stored in the latent heat storage material is taken out to the outside. Fins are provided above and below the outer surface of each tube. As a result, in the heat storage mode, the latent heat storage material on both sides of the fins is heated and liquefied, forming a liquefaction zone that runs vertically through the inside of the shell.

[0004] Patent Document 2 describes a heat storage device including a heat accumulator that stores heat as latent heat and releases the latent heat. A latent heat storage material is accommodated in a predetermined area of ​​the heat accumulator. The heat accumulator may be a shell-and-tube type heat exchanger. In this heat storage device, a latent heat storage material temperature sensor may be provided at a position that combines a location where the temperature distribution of the latent heat storage material is the lowest and a location where the temperature distribution of the latent heat storage material is the highest. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2-52950 [Patent Document 2] JP 2014-136974 A Summary of the Invention [Problem to be solved by the invention]

[0006] The present disclosure provides a heat storage device having separate spaces inside a shell that are connected by a plurality of heat transfer tubes, which is advantageous for sufficiently melting a latent heat storage material in a short period of time. [Means for solving the problem]

[0007] The heat storage device in the present disclosure is a shell having an internal space including a first space, a second space separated from the first space, and a third space formed between the first space and the second space, the first space, the third space, and the second space being disposed along a reference plane; A latent heat storage material accommodated in the third space; A plurality of heat transfer tubes having an outer surface in contact with the third space and communicating the first space with the second space; A melting assistance mechanism that assists in melting the latent heat storage material in the center of the bottom of the third space when the latent heat storage material is melted by heat radiation from a heat medium passing through the inside of the plurality of heat transfer tubes from the first space to the second space. A thermal storage device is provided. Effect of the Invention

[0008] The above-mentioned heat storage device has a first space and a second space separated from each other and connected by a plurality of heat transfer tubes inside the shell, which is advantageous for sufficiently melting the latent heat storage material in a short period of time. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view of the heat storage device according to the first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view conceptually showing the flow of heat in a heat storage device according to a reference example. [Diagram 3] FIG. 3 is a cross-sectional view of a heat storage device according to a modified example. [Figure 4] FIG. 4 is a cross-sectional view of the heat storage device according to the second embodiment. [Diagram 5] FIG. 5 is a cross-sectional view of a heat storage device according to another modified example. [Figure 6] FIG. 6 is a flow chart for controlling the heater of the heat storage device shown in FIG. [Figure 7] FIG. 7 is a cross-sectional view of a heat storage device according to the third embodiment. [Figure 8] FIG. 8 is a cross-sectional view of a heat storage device according to still another modified example. [Figure 9] FIG. 9 is a cross-sectional view of the heat storage device according to the fourth embodiment. [Figure 10] FIG. 10 is a cross-sectional view of a heat storage device according to still another modified example. [Figure 11] FIG. 11 is a cross-sectional view of the heat storage device taken along line II in FIG. [Figure 12] FIG. 12 is a cross-sectional view of a heat storage device according to the fifth embodiment. [Figure 13] FIG. 13 is a plan view of the heat transfer fin shown in FIG. [Figure 14] FIG. 14 is a cross-sectional view of a heat storage device according to still another modified example. [Figure 15] FIG. 15 is a cross-sectional view of a heat storage device according to still another modified example. [Figure 16] FIG. 16 is a cross-sectional view of the heat storage device taken along line VI-VI in FIG. [Figure 17] FIG. 17 is a cross-sectional view of a heat storage device according to the sixth embodiment. [Figure 18] FIG. 18 is a flowchart of a process for determining whether the latent heat storage material has been sufficiently melted in the heat storage device shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (Findings on which this disclosure is based) When storing latent heat in the latent heat storage material housed inside the shell, it is possible to melt the latent heat storage material by passing a heat medium inside a plurality of heat transfer tubes having an outer surface in contact with the space inside the shell in which the latent heat storage material is housed. In this case, it is possible to form inside the shell a space for storing the heat medium to be led into the plurality of heat transfer tubes and a space for storing the heat medium that has passed through the plurality of heat transfer tubes. In other words, it is possible to form two spaces separated from each other and connected by the plurality of heat transfer tubes inside the shell in the heat storage device.

[0011] The present inventors have newly discovered that when storing latent heat in such a heat storage device, the latent heat storage material in a specific location is less likely to melt than the latent heat storage material in other locations. Therefore, the present inventors have conducted extensive research to develop a technology that is advantageous for sufficiently melting the latent heat storage material in a short period of time in a heat storage device having such a configuration. As a result, the present inventors have finally devised the heat storage device disclosed herein.

[0012] From another perspective, the present inventors have conducted intensive research based on the above findings to develop an advantageous technique for accurately determining whether the latent heat storage material has sufficiently melted. As a result, the present inventors have devised another heat storage device according to the present disclosure.

[0013] (Summary of one aspect of the present disclosure) The heat storage device according to the first aspect of the present disclosure includes: a shell having an internal space including a first space, a second space separated from the first space, and a third space formed between the first space and the second space, the first space, the third space, and the second space being disposed along a reference plane; A latent heat storage material accommodated in the third space; A plurality of heat transfer tubes having an outer surface in contact with the third space and communicating the first space with the second space; The heat transfer tube is provided with a melting assistance mechanism that assists in melting the latent heat storage material in the center of the bottom of the third space when the latent heat storage material is melted by heat radiation from a heat medium passing through the inside of the plurality of heat transfer tubes from the first space to the second space.

[0014] In the absence of a melting assistance mechanism, when the latent heat storage material is melted by heat dissipation from the heat medium passing through the insides of the multiple heat transfer tubes from the first space to the second space, the latent heat storage material in the center of the bottom of the third space is less likely to melt than other parts of the third space. This is because the heat of the heat medium is easily transferred to the latent heat storage material by convective heat transfer in the latent heat storage material and thermal conduction on the inner surface of the shell, but this heat is less likely to be transferred to the center of the bottom of the third space. According to the first aspect, the melting assistance mechanism assists in the melting of the latent heat storage material in the center of the bottom of the third space, so that the latent heat storage material can be sufficiently melted in a short period of time.

[0015] In a second aspect of the present disclosure, for example, in the heat storage device according to the first aspect, the melting assistance mechanism may include a heat insulating material overlapping the central portion below the third space in a direction parallel to the reference plane. According to the second aspect, when the latent heat storage material is melted, the heat insulating material acts to suppress heat dissipation from the latent heat storage material in the central portion of the bottom of the third space to the outside of the heat storage device, and the melting of the latent heat storage material in the central portion is assisted. As a result, the latent heat storage material can be sufficiently melted in a short period of time.

[0016] In the third aspect of the present disclosure, for example, in the heat storage device according to the second aspect, the heat insulating material may have an air layer or a vacuum layer. According to the third aspect, the heat insulating material has high heat insulating performance, and when the latent heat storage material is melted, the melting of the latent heat storage material is assisted in the center of the bottom of the third space. As a result, the latent heat storage material can be sufficiently melted in a short period of time.

[0017] In a fourth aspect of the present disclosure, for example, in the heat storage device according to the first aspect, the melting assistance mechanism may heat the bottom when melting the latent heat storage material. According to the fourth aspect, when melting the latent heat storage material, the latent heat storage material is heated in the center of the bottom of the third space, and melting of the latent heat storage material in the center is assisted. As a result, the latent heat storage material can be sufficiently melted in a short period of time.

[0018] In a fifth aspect of the present disclosure, for example, in the heat storage device according to the fourth aspect, the melting assistance mechanism may include a flow path formed below the bottom and passing a heat medium to heat the bottom when melting the latent heat storage material. According to the fifth aspect, when melting the latent heat storage material, the latent heat storage material in the center of the bottom of the third space is heated by the flow of the heat medium in the flow path, and melting of the latent heat storage material in the center is assisted. As a result, the latent heat storage material can be sufficiently melted in a short period of time.

[0019] In a sixth aspect of the present disclosure, for example, in the heat storage device according to the fourth aspect, the melting assistance mechanism may include a heater that selectively heats the central portion of the third space. According to the sixth aspect, when melting the latent heat storage material, the latent heat storage material in the central portion of the bottom of the third space is selectively heated by the heater, and melting of the latent heat storage material in the central portion is assisted. As a result, the latent heat storage material can be sufficiently melted in a short period of time.

[0020] In the seventh aspect of the present disclosure, for example, in the heat storage device according to the sixth aspect, the melting assistance mechanism may cause the heater to generate heat when the temperature of the heat medium in the first space is higher than the melting temperature of the latent heat storage material. According to the seventh aspect, when the latent heat storage material is melted by heat dissipation from the heat medium passing through the insides of the multiple heat transfer tubes from the first space to the second space, the heater generates heat, and the latent heat storage material in the center of the bottom of the third space is heated. This assists in melting the latent heat storage material in the center, allowing the latent heat storage material to be sufficiently melted in a short period of time. In this way, the heater generates heat when it is necessary to melt the latent heat storage material, so that the amount of energy consumed by the heater to generate heat can be reduced.

[0021] In an eighth aspect of the present disclosure, for example, in the heat storage device according to the sixth or seventh aspect, the melting assistance mechanism may stop the heater from generating heat when the temperature of the latent heat storage material in the center is equal to or higher than a predetermined temperature. According to the eighth aspect, for example, the heater stops generating heat in response to the latent heat storage material in the center of the bottom of the third space approaching the melting temperature. This makes it possible to reduce the energy consumption associated with the generation of heat by the heater when it is necessary to melt the latent heat storage material.

[0022] In a ninth aspect of the present disclosure, for example, in the heat storage device according to any one of the sixth to eighth aspects, the melting assistance mechanism may cause the heater to generate heat when the state of charge of the battery supplying power to the heater is equal to or higher than a predetermined level. According to the ninth aspect, the heat generation of the heater can be adjusted according to the state of charge of the battery.

[0023] In a tenth aspect of the present disclosure, for example, in the heat storage device according to any one of the first to ninth aspects, the plurality of heat transfer tubes may have a lowest heat transfer tube located at the lowest position inside the shell. In addition, the melting assistance mechanism may include a first portion of the inner surface of the shell facing the lowest heat transfer tube below the lowest heat transfer tube. Furthermore, the distance between the lowest heat transfer tube and the first portion may be smaller than the distance between the heat transfer tubes other than the lowest heat transfer tube and the inner surface of the shell. According to the tenth aspect, since the distance between the lowest heat transfer tube and the first portion is small, melting of the latent heat storage material in the center of the bottom of the third space is assisted. As a result, the latent heat storage material can be sufficiently melted in a short period of time.

[0024] In an eleventh aspect of the present disclosure, for example, in the heat storage device according to the tenth aspect, the first portion may have a protruding portion protruding toward the central portion. According to the eleventh aspect, the protruding portion can reduce the distance between the lowermost heat transfer tube and the first portion.

[0025] In a twelfth aspect of the present disclosure, for example, in the heat storage device according to any one of the first to eleventh aspects, the melting assistance mechanism may adjust the amount of heat radiation from the plurality of heat transfer tubes to assist in melting the latent heat storage material in the central portion when melting the latent heat storage material. According to the twelfth aspect, the adjustment of the amount of heat radiation from the plurality of heat transfer tubes assists in melting the latent heat storage material in the central portion. As a result, the latent heat storage material can be sufficiently melted in a short period of time.

[0026] In a thirteenth aspect of the present disclosure, for example, in the heat storage device according to the twelfth aspect, the plurality of heat transfer tubes may include a first heat transfer tube disposed near the bottom of the third space and a second heat transfer tube disposed above the first heat transfer tube. In addition, the melting assistance mechanism may make the amount of heat dissipated from the first heat transfer tube higher than the amount of heat dissipated from the second heat transfer tube when melting the latent heat storage material. According to the thirteenth aspect, since the amount of heat dissipated from the first heat transfer tube is higher than the amount of heat dissipated from the second heat transfer tube, melting of the latent heat storage material in the center of the bottom of the third space is assisted. As a result, the latent heat storage material can be sufficiently melted in a short period of time.

[0027] In a fourteenth aspect of the present disclosure, for example, in the heat storage device according to the thirteenth aspect, the melting assistance mechanism may make the flow rate of the heat medium in the first heat transfer tube greater than the flow rate of the heat medium in the second heat transfer tube when melting the latent heat storage material. According to the fourteenth aspect, the flow rate of the heat medium in the first heat transfer tube is greater than the flow rate of the heat medium in the second heat transfer tube, and melting of the latent heat storage material in the center of the bottom of the third space is assisted. As a result, the latent heat storage material can be sufficiently melted in a short period of time.

[0028] In a fifteenth aspect of the present disclosure, for example, in the heat storage device according to the thirteenth or fourteenth aspect, the melting assistance mechanism may include at least one of an inlet for introducing the heat medium into the first space and an outlet for introducing the heat medium from the second space to the outside of the shell. In addition, at least one of the inlet and the outlet may be disposed below the center of the third space in a direction perpendicular to the reference plane. According to the fifteenth aspect, with a relatively simple configuration, it is easy to adjust the amount of heat dissipated from the first heat transfer tube to be higher than the amount of heat dissipated from the second heat transfer tube.

[0029] In a sixteenth aspect of the present disclosure, for example, in the heat storage device according to the twelfth aspect, the plurality of heat transfer tubes may include a first heat transfer tube group and a second heat transfer tube group arranged above the first heat transfer tube group. In addition, the melting assistance mechanism may make the flow rate of the heat medium in the first heat transfer tube group greater than the flow rate of the heat medium in the second heat transfer tube group. According to the sixteenth aspect, the flow rate of the heat medium in the first heat transfer tube group is greater than the flow rate of the heat medium in the second heat transfer tube group, and melting of the latent heat storage material in the center of the bottom of the third space is assisted. As a result, the latent heat storage material can be sufficiently melted in a short period of time.

[0030] In a seventeenth aspect of the present disclosure, for example, in the heat storage device according to any one of the first to eleventh aspects, the plurality of heat transfer tubes may include a first heat transfer tube arranged near the bottom of the third space. In addition, the melting assistance mechanism may include a heat transfer surface that selectively overlaps the central portion of the bottom in the longitudinal direction of the first heat transfer tube and protrudes from the outer surface of the first heat transfer tube toward the inner surface of the shell that is in contact with the central portion. According to the seventeenth aspect, the latent heat storage material in the central portion of the bottom of the third space is heated by heat transfer on the heat transfer surface, and melting of the latent heat storage material in the central portion is assisted. As a result, the latent heat storage material can be sufficiently melted in a short period of time.

[0031] A heat storage device according to an eighteenth aspect of the present disclosure includes: a shell having an internal space including a first space, a second space separated from the first space, and a third space formed between the first space and the second space, the first space, the third space, and the second space being disposed along a reference plane; A latent heat storage material accommodated in the third space; A plurality of heat transfer tubes having an outer surface in contact with the third space and communicating the first space with the second space; A first temperature sensor is provided for detecting the temperature of the latent heat storage material at the center of the bottom of the third space, which is separated from the first space and the second space, when the latent heat storage material is melted by heat radiation from a heat medium passing through the inside of the plurality of heat transfer tubes from the first space to the second space.

[0032] As described above, when the latent heat storage material is melted by heat dissipation from the heat medium passing through the insides of the multiple heat transfer tubes from the first space to the second space, the latent heat storage material in the center of the bottom of the third space is less likely to melt than other parts of the third space. According to the 18th aspect, the temperature of the latent heat storage material in the center of the bottom of the third space, where the latent heat storage material is less likely to melt, can be detected by the first temperature sensor, and it can be accurately determined that the latent heat storage material has been sufficiently melted.

[0033] In a 19th aspect of the present disclosure, for example, the heat storage device according to the 18th aspect may further include an arithmetic circuit that determines whether the latent heat storage material is sufficiently melted in the third space when the latent heat storage material is melted. In addition, the arithmetic circuit may determine that the latent heat storage material is sufficiently melted when the temperature of the latent heat storage material detected by the first temperature sensor is equal to or higher than a predetermined temperature. According to the 19th aspect, whether the latent heat storage material is sufficiently melted can be determined based on the detection result of the first temperature sensor, and it can be accurately determined that the latent heat storage material is sufficiently melted.

[0034] In a twentieth aspect of the present disclosure, for example, the heat storage device according to the nineteenth aspect may further include a second temperature sensor that detects the temperature of the heat medium in the second space, and a calculation circuit that determines whether the latent heat storage material in the third space has been sufficiently melted when the latent heat storage material is melted. In addition, the calculation circuit may determine that the latent heat storage material has been sufficiently melted when the temperature of the latent heat storage material detected by the first temperature sensor is equal to or higher than a first predetermined temperature and the temperature of the heat medium detected by the second temperature sensor is equal to or higher than a second predetermined temperature. According to the twentieth aspect, the sufficient melting of the latent heat storage material can be determined based on the detection results of the first temperature sensor and the second temperature sensor, and it can be accurately determined that the latent heat storage material has been sufficiently melted.

[0035] Hereinafter, the embodiments will be described in detail with reference to the drawings. The following embodiments are merely examples, and the present disclosure is not limited to the following embodiments. In the accompanying drawings, the X-axis, the Y-axis, and the Z-axis are mutually perpendicular, the XY plane is horizontal, and the negative direction of the Z-axis is the direction of gravity.

[0036] (Embodiment 1) FIG. 1 is a cross-sectional view of a heat storage device 1a of the first embodiment. As shown in FIG. 1, the heat storage device 1a includes a shell 10, a latent heat storage material 20, a plurality of heat transfer tubes 30, and a melting assistance mechanism 40. The shell 10 has an internal space including a first space 11, a second space 12, and a third space 13. The second space 12 is separated from the first space 11. The third space 13 is formed between the first space 11 and the second space 12. The first space 11, the third space 13, and the second space 12 are arranged along a reference plane. The reference plane is, for example, horizontal and is a plane parallel to the XY plane. The latent heat storage material 20 is accommodated in the third space 13. The plurality of heat transfer tubes 30 have an outer surface 31 in contact with the third space 13. In addition, the plurality of heat transfer tubes 30 communicate with the first space 11 and the second space 12. The melting assistance mechanism 40 assists in melting the latent heat storage material 20 in the central portion 25c of the bottom 25 of the third space 13 when the latent heat storage material 20 is melted by heat dissipation from the heat medium passing through the insides of the multiple heat transfer tubes 30 from the first space 11 to the second space 12.

[0037] The bottom 25 of the third space 13 means, for example, a space below the lowest heat transfer tube 30 of the multiple heat transfer tubes 30 in the third space 13. The central portion 25c of the bottom 25 means, for example, a portion other than the portions located at both ends of the heat transfer tube 30 in the longitudinal direction when the bottom 25 is divided into four equal parts in the longitudinal direction of the heat transfer tube 30.

[0038] 2 is a cross-sectional view of a heat storage device 3 according to a reference example. The heat storage device 3 is configured similarly to the heat storage device 1a, except that it does not include a melting assistance mechanism 40. The components of the heat storage device 3 corresponding to those of the heat storage device 1a are given the same reference numerals, and detailed explanations are omitted.

[0039] In FIG. 2, the solid arrows indicate the flow of the heat medium when the latent heat storage material 20 is melted. In FIG. 2, the dashed arrows conceptually indicate the flow of heat when the latent heat storage material 20 is melted. When the latent heat storage material 20 is melted by heat radiation from the heat medium passing through the insides of the heat transfer tubes 30 from the first space 11 to the second space 12, the heat is transferred in the positive direction of the Z axis by convection heat transfer in the latent heat storage material 20. For example, when the latent heat storage material 20 is melted by heat radiation from the heat medium passing through the insides of the heat transfer tubes 30 from the first space 11 to the second space 12, the heat medium is stored in each of the first space 11 and the second space 12. The heat of the heat medium stored in the first space 11 and the second space 12 is transferred horizontally by thermal conduction in the inner surface 14 of the shell 10. For this reason, as shown in FIG. 2, the heat of the heat medium is not easily transferred to the central portion 25c. For this reason, the latent heat storage material 20 tends to remain in a solid phase in the central portion 25c, making it difficult to sufficiently melt the latent heat storage material 20 in a short period of time.

[0040] On the other hand, in the heat storage device 1a, when the latent heat storage material 20 is melted, the melting assistance mechanism 40 assists in melting the latent heat storage material 20 in the central portion 25c. This allows the latent heat storage material 20 to be sufficiently melted in a short period of time. For example, the entire latent heat storage material 20 can be completely melted in a short period of time.

[0041] The melting assist mechanism 40 is not limited to a specific mechanism as long as it can assist the melting of the latent heat storage material 20 in the central portion 25c. The melting assist mechanism 40 can melt the entire latent heat storage material 20 in a shorter time under the same conditions, for example, compared to a case in which the melting assist mechanism 40 does not exist. The melting assist mechanism 40 may be a mechanism that promotes the transfer of heat to the central portion 25c, or may be a mechanism that suppresses heat radiation from the central portion 25c.

[0042] 1, in the heat storage device 1a, the melting assistance mechanism 40 includes, for example, a heat insulating material 41. The heat insulating material 41 overlaps the central portion 25c in a direction parallel to the reference plane below the third space 13. When the latent heat storage material 20 is melted, the heat insulating material 41 acts to suppress heat dissipation from the latent heat storage material 20 in the central portion 25c to the outside of the heat storage device 1a, and assists in the melting of the latent heat storage material 20 in the central portion 25c.

[0043] The material constituting the insulating material 41 is not limited to a specific material as long as it can assist the melting of the latent heat storage material 20 in the central portion 25c when the latent heat storage material 20 is melted. The material constituting the insulating material 41 may be resin, metal, glass, or ceramics. The configuration of the insulating material 41 is also not limited to a specific configuration. The insulating material 41 may be a foam or a fiber aggregate. The insulating material 41 may be a vacuum insulating material.

[0044] As shown in FIG. 1, the heat insulating material 41 is disposed, for example, below the third space 13 so as to selectively overlap the central portion 25c of the entire third space 13.

[0045] The center of the heat insulating material 41 in the longitudinal direction of the heat transfer tube 30 is located, for example, closer to the second space 12 than the center of the third space 13 in the longitudinal direction of the heat transfer tube 30. The heat medium dissipates heat when passing through the insides of the heat transfer tubes 30 from the first space 11 to the second space 12. Therefore, the temperature of the heat medium in the second space 12 is likely to be lower than the temperature of the heat medium in the first space 11. Therefore, for example, in the heat storage device 3, the solid-phase latent heat storage material 20 is likely to remain in a portion of the central portion 25c closer to the second space 12. On the other hand, in the heat storage device 1a, the center of the heat insulating material 41 is located closer to the second space 12 than the center of the third space 13, so that the latent heat storage material 20 can be more reliably melted sufficiently in a short period of time.

[0046] As shown in FIG. 1, the heat storage device 1a includes, for example, a first partition 15a and a second partition 15b. Each of the first partition 15a and the second partition 15b is, for example, a plate-shaped member. The first partition 15a divides the internal space of the shell 10 into a first space 11 and a third space 13. For example, the periphery of the first partition 15a is joined to the inner surface 14 of the shell 10 between the first space 11 and the third space 13. The second partition 15b divides the internal space of the shell 10 into a second space 12 and a third space 13. For example, the periphery of the second partition 15b is joined to the inner surface 14 of the shell 10 between the second space 12 and the third space 13. Each of the first partition 15a and the second partition 15b has a plurality of through holes. One end of each of the plurality of heat transfer tubes 30 is joined to the first partition 15a while being disposed in the plurality of through holes of the first partition 15a. The other ends of the heat transfer tubes 30 are respectively arranged in the through holes of the second partition 15b and joined to the second partition 15b. In this way, the heat transfer tubes 30 communicate between the first space 11 and the second space 12.

[0047] 1, the heat storage device 1a has, for example, an inlet 17a and an outlet 17b. The inlet 17a is in contact with the first space 11. The heat medium outside the heat storage device 1a passes through the inlet 17a, is led to the first space 11, and is stored in the first space 11. The heat medium stored in the first space 11 passes through a plurality of heat transfer tubes 30, is led to the second space 12, and is stored in the second space 12. The heat medium stored in the second space 12 passes through the outlet 17b and is led to the outside of the heat storage device 1a.

[0048] The operation of the heat storage device 1a includes, for example, a heat storage operation and a heat dissipation operation. In the heat storage operation, a heat medium having a temperature higher than the melting temperature of the latent heat storage material 20 is supplied to the heat storage device 1a through the inlet 17a, and the latent heat storage material 20 is heated by the heat medium, and the latent heat storage material 20 melts and stores latent heat. On the other hand, in the heat dissipation operation, a heat medium having a temperature lower than the melting temperature of the latent heat storage material 20 is supplied to the heat storage device 1a through the inlet 17a. The temperature of the heat medium increases by receiving the latent heat stored in the latent heat storage material 20. The latent heat storage material 20 changes to, for example, a solid phase. After that, the heat medium is supplied to the outside of the heat storage device 1a, for example, to meet the heat demand.

[0049] The latent heat storage material 20 is not limited to a specific substance. The latent heat storage material 20 contains, for example, a metal salt or a metal salt hydrate as a main component. This makes it easier for the latent heat storage material 20 to have the desired supercooling stability. In this specification, the term "main component" refers to the component that is contained in the largest amount by mass.

[0050] The metal salt may be a sodium salt, a lithium salt, a potassium salt, a calcium salt, a magnesium salt, or a barium salt, and the metal salt may be an iron salt or an aluminum salt.

[0051] The latent heat storage material 20 may contain sodium acetate as a main component, which makes it easier for the latent heat storage material 20 to have the desired supercooling stability with greater certainty.

[0052] The main component of the latent heat storage material 20 may be a predetermined hydrate. For example, it may be a hydrate of the above-mentioned metal salts. Examples of hydrates are sodium sulfate decahydrate, sodium hydrogen sulfate monohydrate, lithium chlorate trihydrate, lithium perchlorate trihydrate, potassium fluoride dihydrate, potassium fluoride tetrahydrate, calcium chloride dihydrate, calcium chloride tetrahydrate, calcium chloride hexahydrate, lithium nitrate trihydrate, sodium sulfate decahydrate, sodium carbonate heptahydrate, sodium carbonate decahydrate, calcium bromide dihydrate, disodium hydrogen phosphate dihydrate, disodium hydrogen phosphate heptahydrate, disodium hydrogen phosphate dodecahydrate, ferric chloride tetrahydrate, ferric chloride hexahydrate, sodium thiosulfate pentahydrate, magnesium sulfate heptahydrate, lithium acetate dihydrate, sodium hydroxide monohydrate, barium hydroxide monohydrate, barium hydroxide octahydrate, sodium pyrophosphate decahydrate, trisodium phosphate hexahydrate, trisodium phosphate octahydrate, and trisodium phosphate dodecahydrate.

[0053] The latent heat storage material 20 may further include other components such as a stabilizer and water.

[0054] The heat medium used in the heat storage device 1a is not limited to a specific substance. The heat medium may be engine coolant such as antifreeze, long life coolant (LLC), or automatic transmission fluid (ATF).

[0055] 3 is a cross-sectional view of a heat storage device 1b according to a modified example of the heat storage device 1a. The heat storage device 1b is configured similarly to the heat storage device 1a, except for parts that will be particularly described. The same reference numerals are used to designate components of the heat storage device 1b that correspond to those of the heat storage device 1a, and detailed descriptions thereof will be omitted. The description of the heat storage device 1a also applies to the heat storage device 1b, unless there is a technical contradiction.

[0056] In the heat storage device 1b, the heat insulating material 41 has an air layer 41a. This allows the heat insulating material 41 to have high heat insulating performance, and when melting the latent heat storage material 20, melting of the latent heat storage material 20 is assisted in the central portion 25c. The heat insulating material 41 may have a vacuum layer instead of the air layer 41a.

[0057] (Embodiment 2) 4 is a cross-sectional view of a heat storage device 1c according to a second embodiment. The heat storage device 1c is configured similarly to the heat storage device 1a, except for the parts that will be particularly described. The components of the heat storage device 1c that correspond to the components of the heat storage device 1a are given the same reference numerals, and detailed description will be omitted. The description of the heat storage device 1a also applies to the heat storage device 1c, unless there is a technical contradiction.

[0058] In the heat storage device 1c, the melting assistance mechanism 40 heats the bottom 25 of the third space 13 when melting the latent heat storage material 20. With this configuration, the latent heat storage material 20 is heated in the central portion 25c when melting the latent heat storage material 20, and the melting of the latent heat storage material 20 in the central portion 25c is assisted. As a result, the latent heat storage material 20 can be sufficiently melted in a short period of time.

[0059] 4, the melting assistance mechanism 40 includes, for example, a flow path 42a. The flow path 42a is formed below the bottom 25. When melting the latent heat storage material 20, the melting assistance mechanism 40 passes a heat medium through the flow path 42a to heat the bottom 25. As a result, when melting the latent heat storage material 20, the latent heat storage material 20 in the central portion 25c is heated by the flow of the heat medium through the flow path 42a, and the melting of the latent heat storage material 20 in the central portion 25c is assisted.

[0060] As shown in FIG. 4, the flow path 42a communicates with the first space 11 and the second space 12. With this configuration, a part of the heat medium stored in the first space 11 can be guided to the flow path 42a. In addition, the heat medium that has passed through the flow path 42a can be discharged to the outside of the heat storage device 1c together with the heat medium that has passed through the heat transfer tubes 30. For example, the shell 10 that contacts the bottom of the first space 11 has a communication hole 42p that communicates the first space 11 and the flow path 42a. The shell 10 that contacts the bottom of the second space 12 has a communication hole 42q that communicates the second space 12 and the flow path 42a. A heat medium different from the heat medium stored in the first space 11 may be supplied to the flow path 42a.

[0061] 5 is a cross-sectional view of a heat storage device 1d according to a modified example of the heat storage device 1c. The heat storage device 1d is configured similarly to the heat storage device 1c, except for parts that will be particularly described. The components of the heat storage device 1d that correspond to the components of the heat storage device 1c are given the same reference numerals, and detailed description will be omitted. The description of the heat storage device 1c also applies to the heat storage device 1d, unless there is a technical contradiction.

[0062] In the heat storage device 1d, the melting assistance mechanism 40 includes, for example, a heater 42b. The heater 42b selectively heats the central portion 25c with respect to the third space 13. According to such a configuration, when the latent heat storage material 20 is melted, the latent heat storage material 20 in the central portion 25c is selectively heated by the heater 42b, and the melting of the latent heat storage material 20 in the central portion 25c is assisted.

[0063] In the heat storage device 1d, the melting assistance mechanism 40 causes the heater 42b to generate heat, for example, when the temperature of the heat medium in the first space 11 is higher than the melting temperature of the latent heat storage material 20. In this case, the heater 42b generates heat when melting the latent heat storage material 20, and the latent heat storage material 20 in the central portion 25c is heated. This assists in the melting of the latent heat storage material 20 in the central portion 25c, and the latent heat storage material 20 can be sufficiently melted in a short period of time. In this way, the heater 42b generates heat when it is necessary to melt the latent heat storage material 20, so that the amount of energy consumed by the heat generated by the heater 42b can be reduced.

[0064] 5, the heat storage device 1d includes, for example, a temperature sensor 43a and a controller 45. The temperature sensor 43a detects the temperature of the heat medium in the first space 11. The controller 45 controls the heater 42b. The controller 45 is, for example, a digital computer in which a program for controlling the heater 42b is stored in an executable manner.

[0065] In the heat storage device 1d, the melting assistance mechanism 40 stops the heater 42b from generating heat when the temperature of the latent heat storage material 20 in the central portion 25c is equal to or higher than a predetermined temperature. In this case, the heater 42b stops generating heat in response to the latent heat storage material 20 in the central portion 25c of the bottom 25 of the third space 13 approaching its melting temperature. This makes it possible to reduce the amount of energy consumed by the heater 42b generating heat when it is necessary to melt the latent heat storage material 20.

[0066] The heater 42b is, for example, an electric heater such as a resistance heater or an induction heater. The heater 42b is connected to, for example, a battery 47. The battery 47 supplies power to the heater 42b. The melting assistance mechanism 40 causes the heater 42b to generate heat when the state of charge of the battery 47 is equal to or higher than a predetermined level. This allows the amount of heat generated by the heater to be adjusted according to the state of charge of the battery 47. The melting assistance mechanism 40 causes the heater 42b to generate heat when, for example, the state of charge (SOC) of the battery 47 is equal to or higher than 90%. The heater 42b may receive power from a power source other than the battery 47.

[0067] FIG. 6 is a flowchart showing an example of the control of the heater 42b. The series of processes shown in FIG. 6 is executed, for example, during heat storage operation. In step S11, the controller 45 acquires information indicating the SOC of the battery 47, and then proceeds to step S12, where the controller 45 judges whether the SOC of the battery 47 is equal to or higher than a predetermined level P1. If the judgment in step S12 is positive, the controller 45 proceeds to step S15. If the judgment in step S12 is negative, the controller 45 proceeds to step S13, where the controller 45 acquires information indicating the temperature T1 of the heat medium in the first space 11 detected by the temperature sensor 43a. Next, the controller 45 proceeds to step S14, where it judges whether the temperature T1 is higher than the melting temperature Tm of the latent heat storage material 20. If the judgment result in step S14 is positive, the controller 45 proceeds to step S15. If the judgment result in step S14 is negative, the controller 45 returns to step S13.

[0068] In step S15, the controller 45 causes the heater 42b to generate heat. This assists in melting the latent heat storage material 20 in the central portion 25c. Next, the process proceeds to step S16, where the controller 45 acquires information indicating the temperature T2 of the latent heat storage material in the central portion 25c detected by the temperature sensor 43b. Next, the process proceeds to step S17, where the controller 45 determines whether the temperature T2 is equal to or higher than a predetermined temperature Tf. The predetermined temperature Tf is, for example, Tm+α1. Tm is the melting temperature of the latent heat storage material 20, and α1 is, for example, 1°C or higher and 5°C or lower. If the determination result in step S17 is positive, it is determined that the latent heat storage material 20 has sufficiently melted, and the controller 45 proceeds to step S18, where the controller 45 stops the heater 42b from generating heat. This stops the series of processes. On the other hand, if the determination result in step S17 is negative, the process returns to step S16.

[0069] For example, when the heater 42b receives power from a power source other than the battery 47, steps S11 and S12 may be omitted.

[0070] (Embodiment 3) 7 is a cross-sectional view of a heat storage device 1e according to a third embodiment. The heat storage device 1e is configured similarly to the heat storage device 1a, except for parts that will be particularly described. The same reference numerals are used to designate components of the heat storage device 1e that correspond to those of the heat storage device 1a, and detailed description thereof will be omitted. The description of the heat storage device 1a also applies to the heat storage device 1e, unless there is a technical contradiction.

[0071] In the heat storage device 1e, the plurality of heat transfer tubes 30 include a bottom heat transfer tube 30b. The bottom heat transfer tube 30b is located at the lowest position inside the shell 10. The melting assistance mechanism 40 includes a first portion 14f of the inner surface 14 of the shell 10. The first portion 14f faces the bottom heat transfer tube 30b below the bottom heat transfer tube 30b. The distance between the bottom heat transfer tube 30b and the first portion 14f is smaller than the distance between the heat transfer tubes 30 other than the bottom heat transfer tube 30b and the inner surface 14 of the shell 10. According to this configuration, the distance between the bottom heat transfer tube 30b and the inner surface 14 of the shell 10 becomes relatively small, so that the melting of the latent heat storage material 20 in the central portion 25c of the bottom 25 of the third space 13 is assisted. As a result, the latent heat storage material 20 can be sufficiently melted in a short period of time.

[0072] 7, the first portion 14f has, for example, a protruding portion 14t. The protruding portion 14t protrudes toward the central portion 25c. The protruding portion 14t can reduce the distance between the lowest heat transfer tube 30b and the first portion 14f, and can assist in melting the latent heat storage material 20 in the central portion 25c.

[0073] FIG. 8 is a cross-sectional view of a heat storage device 1f according to a modified example of the heat storage device 1e. The heat storage device 1f is configured similarly to the heat storage device 1e, except for parts that will be particularly described. The same reference numerals are used to designate components of the heat storage device 1f that correspond to those of the heat storage device 1e, and detailed description thereof will be omitted. The description of the heat storage device 1e also applies to the heat storage device 1f, unless there is a technical contradiction.

[0074] As shown in FIG. 8, according to the heat storage device 1f, the center of the protruding portion 14t in the longitudinal direction of the heat transfer tube 30 is located closer to the second space 12 than the center of the third space 13 in the longitudinal direction of the heat transfer tube 30. As described above, for example, in the heat storage device 3, the latent heat storage material 20 in the solid phase tends to remain at a location closer to the second space 12 in the central portion 25c. On the other hand, according to the heat storage device 1f, in the longitudinal direction of the heat transfer tube 30, since the center of the protruding portion 14t is located closer to the second space 12 than the center of the third space 13, the latent heat storage material 20 can be more reliably and sufficiently melted in a short period of time.

[0075] As shown in FIG. 8, the first partition 15a has, for example, a cylindrical collar 15c that forms a through hole in which one end of the lowermost heat transfer tube 30b is disposed. The cross section of the collar 15c along the longitudinal direction of the lowermost heat transfer tube 30b protrudes from the third space 13 toward the first space 11 while being curved. The distance a between the protruding portion 14t and the lowermost heat transfer tube 30b in the direction perpendicular to the reference plane satisfies, for example, the condition a < b1. b1 is the distance from the outermost part of the collar 15c to the lowermost heat transfer tube 30b in the direction perpendicular to the reference plane. By satisfying the condition a < b1, the protruding portion 14t can be easily formed. a is, for example, 0.3b1 or more.

[0076] As shown in FIG. 8, the second partition 15b has, for example, a cylindrical collar 15d that forms a through hole in which one end of the lowermost heat transfer tube 30b is disposed. The cross section of the collar 15d along the longitudinal direction of the lowermost heat transfer tube 30b protrudes from the third space 13 toward the second space 12 while being curved. The distance a satisfies, for example, the condition a < b2. b2 is the distance from the outermost part of the collar 15d to the lowermost heat transfer tube 30b in the direction perpendicular to the reference plane. By satisfying the condition a < b2, the protruding portion 14t can be easily formed. a is, for example, 0.3b2 or more. Each of the collar 15c and the collar 15d can be formed, for example, by a flanging process.

[0077] (Embodiment 4) 9 is a cross-sectional view of a heat storage device 1g according to a fourth embodiment. The heat storage device 1g is configured similarly to the heat storage device 1a, except for parts that will be particularly described. The components of the heat storage device 1g that correspond to those of the heat storage device 1a are given the same reference numerals, and detailed description thereof will be omitted. The description of the heat storage device 1a also applies to the heat storage device 1g, unless there is a technical contradiction.

[0078] In the heat storage device 1g, when the latent heat storage material 20 is melted, the melting assistance mechanism 40 adjusts the amount of heat dissipated from the plurality of heat transfer tubes 30 to assist in the melting of the latent heat storage material 20 in the central portion 25c.

[0079] In the heat storage device 1g, for example, the multiple heat transfer tubes 30 include a first heat transfer tube 30m and a second heat transfer tube 30n. The first heat transfer tube 30m is disposed near the bottom 25 of the third space 13 in the multiple heat transfer tubes 30. The second heat transfer tube 30n is disposed above the first heat transfer tube 30m. When melting the latent heat storage material 20, the melting assistance mechanism 40 makes the amount of heat dissipated from the first heat transfer tube 30m higher than the amount of heat dissipated from the second heat transfer tube 30n. According to this configuration, the amount of heat dissipated from the first heat transfer tube 30m is relatively high, and the melting of the latent heat storage material 20 in the central portion 25c is assisted. As a result, the latent heat storage material 20 can be sufficiently melted in a short period of time. In this specification, the "amount of heat dissipated" means the amount of heat released per unit time, and has the dimension of watts (W).

[0080] The number of the first heat transfer tubes 30m may be one or may be two or more. The first heat transfer tube 30m is disposed, for example, below the center of the third space 13 in the direction perpendicular to the reference plane. Furthermore, for example, the lowest heat transfer tube 30 among the plurality of heat transfer tubes 30 may correspond to the first heat transfer tube 30m. When the plurality of heat transfer tubes 30 include a plurality of first heat transfer tubes 30m or a plurality of second heat transfer tubes 30n, the amount of heat dissipated from the first heat transfer tube 30m and the amount of heat dissipated from the second heat transfer tube 30n are the amounts of heat dissipated from each heat transfer tube 30.

[0081] In the heat storage device 1g, the melting assistance mechanism 40, for example, when melting the latent heat storage material 20, makes the flow rate of the heat medium in the first heat transfer tube 30m larger than the flow rate of the heat medium in the second heat transfer tube 30n. In this case, since the flow rate of the heat medium in the first heat transfer tube 30m is relatively large, the amount of heat dissipation from the first heat transfer tube 30m becomes relatively high. As a result, the melting of the latent heat storage material 20 in the central portion 25c is assisted. In this specification, the "flow rate" means, for example, a mass flow rate per unit time, and has a dimension of kg / sec.

[0082] As shown in FIG. 9, in the heat storage device 1g, the melting assistance mechanism 40 includes, for example, at least one of the inlet 17a and the outlet 17b. The melting assistance mechanism 40 may include both the inlet 17a and the outlet 17b. At least one of the inlet 17a and the outlet 17b is disposed below the center of the third space 13 in the direction perpendicular to the reference plane. In this case, with a relatively simple configuration, it is easy to adjust the amount of heat dissipated from the first heat transfer tube 30m to be higher than the amount of heat dissipated from the second heat transfer tube 30n. Both the inlet 17a and the outlet 17b may be disposed below the center of the third space 13 in the direction perpendicular to the reference plane.

[0083] (Embodiment 5) Fig. 10 is a cross-sectional view of a heat storage device 1h according to a fifth embodiment. The heat storage device 1h is configured similarly to the heat storage device 1a, except for the parts that will be particularly described. The components of the heat storage device 1h that correspond to the components of the heat storage device 1a are given the same reference numerals, and detailed description will be omitted. The description of the heat storage device 1a also applies to the heat storage device 1h, unless there is a technical contradiction.

[0084] In the heat storage device 1h, when the latent heat storage material 20 is melted, the melting assistance mechanism 40 adjusts the amount of heat dissipated from the plurality of heat transfer tubes 30 to assist in the melting of the latent heat storage material 20 in the central portion 25c.

[0085] In the heat storage device 1h, for example, the multiple heat transfer tubes 30 include a first heat transfer tube group 30p and a second heat transfer tube group 30q. The second heat transfer tube group 30q is disposed above the first heat transfer tube group 30p in the multiple heat transfer tubes 30. The melting assistance mechanism 40 makes the flow rate of the heat medium in the first heat transfer tube group 30p larger than the flow rate of the heat medium in the second heat transfer tube group 30q. According to the heat storage device 1h, the flow rate of the heat medium in the first heat transfer tube group 30p becomes relatively large, and the melting of the latent heat storage material 20 in the central portion 25c is assisted. The flow rate of the heat medium in the first heat transfer tube group 30p is the sum of the flow rates of the heat medium in the heat transfer tubes 30 belonging to the first heat transfer tube group 30p. The flow rate of the heat medium in the second heat transfer tube group 30q is the sum of the flow rates of the heat medium in the heat transfer tubes 30 belonging to the second heat transfer tube group 30q.

[0086] 11, the number of heat transfer tubes 30 included in the first heat transfer tube group 30p is, for example, greater than the number of heat transfer tubes 30 included in the second heat transfer tube group 30q. The distance between the heat transfer tubes 30 included in the first heat transfer tube group 30p is smaller than the distance between the heat transfer tubes 30 included in the second heat transfer tube group 30q. With this configuration, the flow rate of the heat medium in the first heat transfer tube group 30p tends to be relatively large. The first heat transfer tube group 30p is, for example, disposed below the center of the third space 13 in the direction perpendicular to the reference plane, and the second heat transfer tube group 30q is, for example, disposed above the center of the third space 13 in the direction perpendicular to the reference plane.

[0087] (Embodiment 6) 12 is a cross-sectional view of a heat storage device 1i according to a sixth embodiment. The heat storage device 1i is configured similarly to the heat storage device 1a, except for the parts that will be particularly described. The components of the heat storage device 1i that correspond to the components of the heat storage device 1a are given the same reference numerals, and detailed description will be omitted. The description of the heat storage device 1a also applies to the heat storage device 1i, unless there is a technical contradiction.

[0088] In the heat storage device 1i, the multiple heat transfer tubes 30 include a first heat transfer tube 30m. The first heat transfer tube 30m is disposed near the bottom 25 of the third space 13. As shown in FIG. 12, for example, a heat transfer fin 35a is attached to the first heat transfer tube 30m. The melting assistance mechanism 40 includes a heat transfer surface 35t. The heat transfer surface 35t is, for example, at least a part of the surface of the heat transfer fin 35a. The heat transfer surface 35t selectively overlaps the central portion 25c of the bottom portion 25 in the longitudinal direction of the first heat transfer tube 30m. In addition, the heat transfer surface 35t protrudes from the outer surface of the first heat transfer tube 30m toward the inner surface 14 of the shell 10 that is in contact with the central portion 25c. According to this configuration, the latent heat storage material 20 in the central portion 25c is heated by heat transfer on the heat transfer surface 35t, and melting of the latent heat storage material 20 in the central portion 25c is assisted. As a result, the latent heat storage material 20 can be sufficiently melted in a short period of time.

[0089] The heat transfer surface 35t is located, for example, closer to the second space 12 than to the center of the third space 13 in the longitudinal direction of the heat transfer tube 30.

[0090] 12, for example, a gap is formed between the lowest end of the heat transfer fin 35a and the inner surface 14 of the shell 10. In this case, heat can be easily and efficiently transferred to the latent heat storage material 20 in the central portion 25c by the heat transfer fin 35a.

[0091] 13 is a plan view of the heat transfer fin 35a. The heat transfer fin 35a has, for example, slits 35s. The heat transfer fin 35a can be easily attached to the first heat transfer tube 30m by fitting the first heat transfer tube 30m into the slits 35s.

[0092] 14 and 15 are cross-sectional views of heat storage devices 1j and 1k, which are modified examples of the heat storage device 1i. The heat storage devices 1j and 1k are configured similarly to the heat storage device 1i, except for parts that will be particularly described. The components of the heat storage devices 1j and 1k that correspond to the components of the heat storage device 1i are given the same reference numerals, and detailed descriptions are omitted. The explanations regarding the heat storage device 1i also apply to the heat storage devices 1j and 1k, unless there is a technical contradiction.

[0093] As shown in Fig. 14, in the heat storage device 1j, the bottom end of the heat transfer fin 35a is in contact with the inner surface 14 of the shell 10. With such a configuration, the area of ​​the heat transfer surface 35t tends to be large, and heat is easily transferred efficiently to the latent heat storage material 20 in the central portion 25c. In addition, heat that has traveled through the first heat transfer pipe 30m, the heat transfer fin 35a, and the inner surface 14 of the shell 10 is also transferred to the latent heat storage material 20 in the central portion 25c. In this way, the latent heat storage material 20 in the central portion 25c can be heated from multiple directions, and the latent heat storage material 20 can be sufficiently melted in a short period of time.

[0094] As shown in FIG. 15, in the heat storage device 1k, the heat transfer fins 35a are configured to partition the third space 13. FIG. 16 is a cross-sectional view of the heat storage device 1k taken along the line VI-VI in FIG. 15. As shown in FIG. 16, the heat transfer fins 35a have, for example, a plurality of first through holes 36 and a plurality of second through holes 37. A plurality of heat transfer tubes 30 are arranged in each of the plurality of first through holes 36. With this configuration, the heat transfer fins 35a facilitates the transfer of heat from the plurality of heat transfer tubes 30 toward the central portion 25c, and the central portion 25c is easily heated. As a result, the latent heat storage material 20 can be sufficiently melted in a short period of time.

[0095] The two spaces separated by the heat transfer fin 35a communicate with each other via the plurality of second through holes 37. This allows the crystallization of the latent heat storage material 20 to propagate.

[0096] The heat transfer fins 35a are in contact with, for example, the inner surface 14 of the shell 10. The heat transfer fins 35a may be joined to the shell 10. With this configuration, the shell 10 is reinforced by the heat transfer fins 35a, making it easy to reduce the thickness of the shell 10. The thickness of the shell 10 is half the difference between the outer diameter and the inner diameter of the shell 10.

[0097] (Embodiment 7) FIG. 17 is a cross-sectional view of a heat storage device 1l according to a seventh embodiment. The heat storage device 1l is configured similarly to the heat storage device 1a, except for parts that will be particularly described. The components of the heat storage device 1l that correspond to the components of the heat storage device 1a are given the same reference numerals, and detailed description will be omitted. The description of the heat storage device 1a also applies to the heat storage device 1l, unless there is a technical contradiction.

[0098] 17, the heat storage device 1l further includes a first temperature sensor 51. The first temperature sensor 51 detects the temperature of the latent heat storage material 20 in the central portion 25c when the latent heat storage material 20 is melted by heat dissipation from the heat medium passing through the insides of the multiple heat transfer tubes 30 from the first space 11 to the second space 12. According to the heat storage device 1l, the first temperature sensor 51 can detect the temperature of the latent heat storage material 20 in the central portion 25c where the latent heat storage material 20 is less likely to melt, and it can be accurately determined that the latent heat storage material 20 has been sufficiently melted.

[0099] The first temperature sensor 51 detects the temperature of the latent heat storage material 20 located, for example, closer to the second space 12 than to the center of the third space 13 in the longitudinal direction of the heat transfer tube 30. With such a configuration, it is possible to more reliably and accurately determine whether the latent heat storage material 20 has been sufficiently melted.

[0100] The heat storage device 1l may or may not include the melting assistance mechanism 40.

[0101] As shown in FIG. 17, the heat storage device 1l further includes, for example, an arithmetic circuit 60. When melting the latent heat storage material 20, the arithmetic circuit 60 determines that the latent heat storage material 20 has been sufficiently melted in the third space 13. When the temperature of the latent heat storage material 20 detected by the first temperature sensor 51 is equal to or higher than a predetermined temperature, the arithmetic circuit 60 determines that the latent heat storage material 20 has been sufficiently melted. In this way, according to the heat storage device 1l, it is possible to accurately determine that the latent heat storage material 20 has been sufficiently melted based on the detection result of the first temperature sensor 51. The arithmetic circuit 60 may determine that the latent heat storage material 20 has been completely melted when the temperature of the latent heat storage material 20 detected by the first temperature sensor 51 is equal to or higher than a predetermined temperature.

[0102] As shown in FIG. 18, the heat storage device 1l further includes, for example, a second temperature sensor 52. The second temperature sensor 52 detects the temperature of the heat medium. The arithmetic circuit 60 determines that the latent heat storage material 20 is sufficiently melted when, for example, the temperature Ti is equal to or higher than a first predetermined temperature Tx and the temperature Tj is equal to or higher than a second predetermined temperature Ty. The temperature Ti is the temperature of the latent heat storage material 20 detected by the first temperature sensor 51, and the temperature Tj is the temperature of the heat medium detected by the second temperature sensor 52. For example, when there is a situation in which another heat source exists near the central portion 25c, the sufficient melting of the latent heat storage material 20 may be erroneously determined based only on the detection result of the first temperature sensor 51. On the other hand, according to the heat storage device 1l, the sufficient melting of the latent heat storage material can be determined based on the detection results of the first temperature sensor 51 and the second temperature sensor 52, and it can be accurately determined that the latent heat storage material has been sufficiently melted. Note that sufficient melting of the latent heat storage material 20 may be determined based only on the detection result of the first temperature sensor 51. The arithmetic circuit 60 may determine that the latent heat storage material 20 is completely melted when, for example, the temperature Ti is equal to or higher than a first predetermined temperature Tx and the temperature Tj is equal to or higher than a second predetermined temperature Ty.

[0103] The predetermined temperature Tx is, for example, Tm+α2, where Tm is the melting temperature of the latent heat storage material 20, and α2 is, for example, 1° C. or more and 5° C. or less. The predetermined temperature Ty is, for example, Tm+β, where β is, for example, 1° C. or more and 5° C. or less.

[0104] The second temperature sensor 52 detects, for example, the temperature of the heat medium in the second space 12. This makes it possible to more reliably and accurately determine whether the latent heat storage material 20 has been sufficiently melted.

[0105] FIG. 18 is a flow chart showing an example of a process for determining whether the latent heat storage material 20 in the heat storage device 1l has melted sufficiently. First, in step S21, the arithmetic circuit 60 acquires information indicating the detected temperature Ti of the first temperature sensor 51. Next, the process proceeds to step S22, where the arithmetic circuit 60 acquires information indicating the detected temperature Tj of the second temperature sensor 52. Next, the process proceeds to step S23, where the arithmetic circuit 60 determines whether the conditions Ti≧Tx and Tj≧Ty are satisfied. If the determination result in step S23 is positive, the arithmetic circuit 60 determines that the latent heat storage material 20 has melted sufficiently, and proceeds to step S24, where a signal indicating the latent heat storage material 20 has melted sufficiently is output to the outside, and a series of processes is completed. On the other hand, if the determination result in step S24 is negative, the process returns to step S21. This allows the latent heat storage material 20 to be accurately determined to have melted sufficiently. [Explanation of symbols]

[0106] 1a, 1b, 1c, 1d, 1e, 1f Heat storage device 1g, 1h, 1i, 1j, 1k, 1l heat storage device 10 Shell 11 First space 12 Second space 13 Third space 14. Inside 14f First part 14t protrusion 17a Inlet 17b Outlet 20 Latent heat storage material 25 Bottom 25c central part 30 Heat transfer tube 30b Bottom heat transfer tube 30m First heat transfer tube 30n second heat transfer tube 30p First heat exchanger tube group 30q 2nd heat exchanger tube group 31 External surface 35t Heat transfer surface 40 Melting assistance mechanism 41 Insulation 41a Air Layer 42a Flow path 42b Heater 51 First temperature sensor 52 Second temperature sensor 60 Arithmetic circuit

Claims

1. a shell having an internal space including a first space, a second space separated from the first space, and a third space formed between the first space and the second space, the first space, the third space, and the second space being disposed along a reference plane; A latent heat storage material accommodated in the third space; A plurality of heat transfer tubes having an outer surface in contact with the third space and communicating the first space with the second space; a melting assistance mechanism that assists in melting the latent heat storage material in a central portion of a bottom of the third space when the latent heat storage material is melted by heat radiation from a heat medium passing through inside the plurality of heat transfer tubes from the first space to the second space, The latent heat storage material is accommodated in the third space so as to be able to cross the plurality of heat transfer tubes and convect from the bottom in a direction opposite to the direction of gravity. Heat storage device.

2. The heat storage device according to claim 1 , wherein the melting assistance mechanism includes a thermal insulating material overlapping the central portion in a direction parallel to the reference plane below the third space.

3. The heat storage device according to claim 2 , wherein the insulating material has an air layer or a vacuum layer.

4. The heat storage device according to claim 1 , wherein the melting assistance mechanism heats the bottom when melting the latent heat storage material.

5. The heat storage device according to claim 4 , wherein the melting assistance mechanism includes a flow path formed below the bottom portion and passing a heat medium therethrough to heat the bottom portion when the latent heat storage material is melted.

6. The heat storage device according to claim 4 , wherein the melting assistance mechanism includes a heater that selectively heats the central portion of the third space.

7. The heat storage device according to claim 6 , wherein the melting assistance mechanism causes the heater to generate heat when a temperature of the heat medium in the first space is higher than a melting temperature of the latent heat storage material.

8. The heat storage device according to claim 6 or 7, wherein the melting assistance mechanism stops the heater from generating heat when a temperature of the latent heat storage material in the central portion is equal to or higher than a predetermined temperature.

9. The heat storage device according to claim 6 , wherein the melting assistance mechanism causes the heater to generate heat when a state of charge of a battery supplying power to the heater is equal to or higher than a predetermined level.

10. The plurality of heat transfer tubes include a lowermost heat transfer tube located at the lowermost position inside the shell, the melting assist mechanism includes a first portion of an inner surface of the shell facing the bottom heat transfer tube below the bottom heat transfer tube, a distance between the lowest heat transfer tube and the first portion is smaller than a distance between the heat transfer tubes other than the lowest heat transfer tube and the inner surface of the shell; The heat storage device according to any one of claims 1 to 9.

11. The heat storage device according to claim 10 , wherein the first portion has a protruding portion protruding toward the central portion.

12. The heat storage device according to claim 1 , wherein the melting assistance mechanism adjusts the amount of heat dissipated from the plurality of heat transfer tubes when melting the latent heat storage material to assist in melting the latent heat storage material in the central portion.

13. the plurality of heat transfer tubes include a first heat transfer tube disposed near the bottom of the third space and a second heat transfer tube disposed above the first heat transfer tube, The melting assist mechanism makes an amount of heat dissipation from the first heat transfer tube higher than an amount of heat dissipation from the second heat transfer tube when melting the latent heat storage material. The heat storage device according to claim 12.

14. The heat storage device according to claim 13 , wherein the melting assistance mechanism makes a flow rate of the heat medium in the first heat transfer pipe greater than a flow rate of the heat medium in the second heat transfer pipe when melting the latent heat storage material.

15. the melting assistance mechanism includes at least one of an inlet for introducing the heat medium into the first space and an outlet for introducing the heat medium from the second space to the outside of the shell, At least one of the inlet and the outlet is disposed below a center of the third space in a direction perpendicular to the reference plane. The heat storage device according to claim 13 or 14.

16. the plurality of heat transfer tubes include a first heat transfer tube group and a second heat transfer tube group arranged above the first heat transfer tube group, The heat storage device according to claim 12 , wherein the melting assistance mechanism makes a flow rate of the heat medium in the first heat transfer tube group greater than a flow rate of the heat medium in the second heat transfer tube group.

17. the plurality of heat transfer tubes include a first heat transfer tube disposed near the bottom of the third space, the melting assistance mechanism selectively overlaps the central portion of the bottom portion in the longitudinal direction of the first heat transfer tube, and includes a heat transfer surface protruding from an outer surface of the first heat transfer tube toward the inner surface of the shell in contact with the central portion. A heat storage device according to any one of claims 1 to 11.

18. a shell having an internal space including a first space, a second space separated from the first space, and a third space formed between the first space and the second space, the first space, the third space, and the second space being disposed along a reference plane; A latent heat storage material accommodated in the third space; A plurality of heat transfer tubes having an outer surface in contact with the third space and communicating the first space with the second space; a first temperature sensor that detects a temperature of the latent heat storage material at a center of a bottom of the third space that is separated from the first space and the second space when the latent heat storage material is melted by heat dissipation from a heat medium passing through inside the plurality of heat transfer tubes from the first space to the second space, The latent heat storage material is accommodated in the third space so as to be able to cross the plurality of heat transfer tubes and convect from the bottom in a direction opposite to the direction of gravity. Heat storage device.

19. Further, a calculation circuit is provided for determining whether the latent heat storage material in the third space is sufficiently melted when the latent heat storage material is melted, The heat storage device according to claim 18 , wherein the arithmetic circuit determines that the latent heat storage material has been sufficiently melted when the temperature of the latent heat storage material detected by the first temperature sensor is equal to or higher than a predetermined temperature.

20. A second temperature sensor for detecting a temperature of the heat medium; and a calculation circuit that determines whether the latent heat storage material in the third space is sufficiently melted when the latent heat storage material is melted. The heat storage device of claim 19, wherein the arithmetic circuit determines that the latent heat storage material has been sufficiently melted when the temperature of the latent heat storage material detected by the first temperature sensor is equal to or higher than a first predetermined temperature and the temperature of the heat medium detected by the second temperature sensor is equal to or higher than a second predetermined temperature.

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