JP2012098001A - Heat storage device and air conditioner with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat storage device that stably holds a heat storage solution in a heat storage container and has superior handling performance, and to provide an air conditioner with the same.SOLUTION: The heat storage container of the heat storage device 20C includes a heat storage solution layer 11, an evaporation prevention layer 13 and an air layer, which are formed in this order. The evaporation prevention layer 13 is composed at least of an organic compound, which is insoluble in the heat storage solution, which has a smaller specific gravity than the heat storage solution, and which has a melting point not less than a normal temperature. Accordingly, a solid evaporation preventing layer is formed in a range of the normal temperature, so that an excessive evaporation of the heat storage solution can effectively be prevented and also the heat storage solution is prevented from leaking outside or being exposed to the air layer during transportation of the heat storage device.

Description

  The present invention relates to a heat storage device using an aqueous solution as a heat storage solution, and an air conditioner including the heat storage device.

  Water is widely used as a heat storage solution (heat storage material, heat storage medium) for heat storage devices because its specific heat capacity is relatively large compared to other substances, is liquid at room temperature, and is low in price. Yes. When water is used as a heat storage solution, it is generally used as a dihydric alcohol aqueous solution to which a dihydric alcohol such as ethylene glycol is added as an “antifreeze”. If the heat storage device using such a heat storage solution is an open air type, a part of the heat storage solution evaporates as the heat storage operation is repeated. Therefore, it is necessary to periodically replenish the heat storage device with the heat storage solution.

  Thus, various techniques for suppressing evaporation of the heat storage solution have been proposed. Specifically, for example, in Patent Document 1, in an open air type heat storage device that is incorporated in a refrigeration cycle of an air conditioner and has a heat storage material mainly composed of water, the heat storage container stores heat. The structure which provided the evaporation suppression means of material is disclosed. Specifically, the heat storage material is exemplified by brine in which water is the main component and 30% ethylene glycol is mixed, and a configuration is disclosed in which an oil film of 1 mm or more is formed on the surface of the heat storage material to serve as an evaporation suppression means. ing.

  Patent Document 2 discloses a configuration in which a moisture evaporation prevention film is provided on the surface of a latent heat storage material in a heat storage device in which a latent heat storage material mainly composed of a hydrated salt is filled in a heat storage tank. . Specifically, what mixed 1 to 2% of xanthan gum as a thickener with sodium acetate trihydrate as a latent heat storage material is illustrated, and paraffin is used as a moisture evaporation prevention film on the surface of the latent heat storage material. Or a polymer film etc. are illustrated. The moisture evaporation prevention film may be basically any material that does not allow moisture to permeate, and may be liquid or solid. However, if there is a gap between the surface of the heat storage material, the moisture will evaporate to some extent. Therefore, it is disclosed that a flexible material is preferable.

  Patent Document 3 discloses a composition containing a moisture evaporation inhibitor, which is a heat storage material composition used for household heating and hot water supply equipment and for cooling electronic components. Specifically, as a heat storage material composition, a supercooling inhibitor, water, a thickener, and a heat transfer promoter are mixed in a predetermined range of composition with a hydrated salt type heat storage material such as sodium acetate trihydrate. What melt | dissolved and stirred is illustrated, Furthermore, what added the liquid paraffin as a water | moisture-content evaporation inhibitor to the said thermal storage material composition is illustrated. The moisture evaporation inhibitor is not limited to liquid paraffin as long as it is insoluble in the heat storage material and has a low specific gravity and a high boiling point. For example, synthetic oils such as animal and vegetable oils and silicone oils, organic solvents and the like are also exemplified. .

  Thus, conventionally, in order to suppress evaporation of the heat storage solution (heat storage material), a heat storage device having a configuration in which an evaporation preventing layer is formed on the upper surface of the heat storage solution is known. A more specific example of such a heat storage device, including a configuration applied to an air conditioner, will be described with reference to FIGS.

FIG. 5A shows a cross section of a conventional heat storage device 910 disclosed in Patent Document 1. FIG. In the heat storage device 910, a heat storage container is configured by a metal heat storage tank 901 and a metal lid 902, and a heat storage material 903 is accommodated in the internal space of the heat storage tank 901. As the heat storage material 903, brine in which water is the main component and 30% ethylene glycol is mixed is used in order to prevent freezing at low temperatures. A plurality of heat-dissipating heat exchangers 4 and a plurality of heat-absorbing heat exchangers 5 are provided in the internal space of the heat-storage tank 901 and in positions immersed in the heat-storage material 903.

  The heat storage material 903 stores the heat released from the heat storage heater 906 and the heat dissipation heat exchanger 904 provided outside the heat storage container, and collects the heat by the heat absorption heat exchanger 905. Since a refrigerant (not shown) flows in the heat exchanger for heat absorption 905, heat is recovered from the heat storage material 903, so that the heat is transferred to the refrigerant and becomes a high temperature. The conventional heat storage device 910 improves the heating start-up characteristics in the refrigeration cycle (not shown) disclosed in Patent Document 1 using such heat storage and heat recovery.

  An oil film 907 having a thickness of, for example, 3 mm is provided on the surface of the heat storage material 903, and the oil film 907 is configured to suppress a decrease due to evaporation of the heat storage material 903. Further, since the opening 908 is provided in the lid 902, the internal pressure of the heat storage container is not excessively increased by evaporation or thermal expansion of the heat storage material 903. The opening 908 is provided with a steam suppression means (not shown) so as not to release steam excessively to the atmosphere. Further, an air layer 909 is formed between the oil film 907 and the lid 902. Thereby, it is comprised so that the one part may not overflow outside a thermal storage container via the opening 908 (and vapor | steam suppression means) by the thermal expansion accompanying the temperature rise of the thermal storage material 903. FIG.

  FIG.5 (b) has shown the structure which incorporated the heat storage apparatus 910 of the said structure in the refrigerating cycle of the air conditioner. The air conditioner includes an indoor unit 911, an expansion valve (not shown), an outdoor unit 912, a compressor 913, and a pipe 916 connecting them. The indoor unit 911 includes an indoor heat exchanger (not shown), the outdoor unit 912 includes an outdoor heat exchanger (not shown), and a refrigerant flows inside the pipe. The indoor unit 911, the expansion valve, the outdoor unit 912, and the compressor 913 constitute a heating heat pump.

  Further, a bypass pipe 914 is provided so as to connect the downstream side in the direction in which the refrigerant flows in the pipe 916 connected to the indoor unit 911 and the upstream side in the direction in which the refrigerant flows out of the pipe 916 connected to the compressor 913. ing. The bypass pipe 914 includes an endothermic heat exchanger 905 and is configured such that the refrigerant flows by opening the two-way valve 915.

  According to the said structure, a refrigerant | coolant becomes high temperature / high pressure by the compressor 913, flows through the inside of the piping 916 along arrow m1 (block arrow filled in black) in the figure, and reaches the thermal storage device 910. Then, heat is dissipated from the high-temperature refrigerant by the heat-dissipating heat exchanger 904 and is stored in the heat storage material 903 in the heat storage device 910. At the same time, the heat storage material 903 is further heated by the heat storage heater 906 provided in the heat storage device 910 and is heated to, for example, 93 to 97 ° C. Therefore, the heat from the heat storage heater 906 is also stored in the heat storage material 903.

  The heat storage material 903, which has become high temperature due to the heat storage, opens the two-way valve 915 so that the refrigerant flowing in the bypass pipe 914 along the direction indicated by the arrow m3 (white block arrow) in the figure is exchanged for heat absorption. Heat through vessel 905. The refrigerant warmed by the heat storage material 903 (recovered heat from the heat storage material 903) reaches the compressor 913, and finally flows to the indoor unit 911 including the indoor heat exchanger, and performs heat exchange in the indoor unit 911. Thus, warm air for heating is generated. Note that the refrigerant having a low temperature after the heat exchange flows through the pipe 916 along the direction indicated by the arrow m2 in the drawing, and returns to the compressor 913 through the outdoor unit 912.

Japanese Patent Laid-Open No. 10-288359 Japanese Patent Laid-Open No. 64-10098 JP 2000-119643 A

  However, in the conventional configuration, it may be insufficient to stably hold the heat storage solution in the heat storage container regardless of whether the evaporation prevention layer is liquid or solid.

  First, if the evaporation prevention layer is composed of a liquid (if it is a liquid layer), the heat storage device is open to the atmosphere, and thus, for example, when the heat storage device is transported, the heat storage solution may leak from the vent hole. There is. Therefore, in order to avoid leakage of the heat storage solution, it is necessary to handle the heat storage device so that it does not shake excessively. That is, from the viewpoint of improving the handleability of the heat storage device, in addition to the function of preventing or suppressing evaporation of the heat storage solution (hereinafter referred to as the evaporation prevention function), the heat storage solution is added to the evaporation prevention layer. The function of preventing or suppressing the leakage (hereinafter referred to as a leakage prevention function) is required.

  On the other hand, if the evaporation prevention layer is made of a solid (if it is a solid layer), the solid layer can improve the airtightness on the upper surface of the heat storage solution. It can be realized well.

  However, for the evaporation prevention layer, when the pressure of the heat storage solution increases, the function of reducing the increase in the pressure and stably holding the heat storage solution in the heat storage container (hereinafter referred to as a pressure relaxation function). .) Is also required. If the evaporation prevention layer is a solid layer and the airtightness on the upper surface of the heat storage solution is high, it will be difficult to effectively realize the pressure relaxation function, resulting in damage to the heat storage container as a result of long-term intermittent use. It can happen. In this case, since the heat storage solution may leak from the damaged portion, the heat storage solution cannot be stably held. Further, if the air tightness on the upper surface of the heat storage solution is lowered in order to improve the pressure relaxation function in the solid layer, the evaporation prevention function and the leakage prevention function are lowered.

  Here, even if the evaporation prevention layer is a solid layer, the material design of the solid layer used as the evaporation prevention layer should be performed so that the evaporation prevention function, the leakage prevention function, and the pressure relaxation function can be satisfied at the same time. Is possible. For example, the gas (vapor or dissolved oxygen) is improved while improving the flexibility of the solid layer and ensuring the barrier property of the liquid (heat storage solution) by selecting the material to be the solid layer, designing the composition, devising the molding method, etc. Etc.) is expected to be ensured. However, since such material design realizes contradictory functions, the manufacturing conditions of the solid layer, such as material selection, composition design, and ingenuity of the molding processing method, become complicated, and as a result, the evaporation prevention layer Incurs high costs.

  The present invention has been made to solve such problems, and provides a heat storage device that can stably hold a heat storage solution in a heat storage container and has excellent handling properties, and an air conditioner including the heat storage device. For the purpose.

In order to solve the above-described problems, a heat storage device according to the present invention includes a heat storage container having a vent hole communicating with outside air, and a heat storage solution layer and an evaporation prevention layer are arranged in this order from the bottom in the heat storage container. And the upper part of the evaporation preventing layer communicates with the outside air, and the heat storage solution layer is composed of a sensible heat storage solution consisting of at least water, and the air layer flows from the vent hole. The evaporation-preventing layer has at least an organic compound having a specific gravity smaller than that of the heat storage solution and a melting point equal to or higher than room temperature.

  Here, the melting point is synonymous with the pour point in the case of fats and oils whose melting point is unclear or a multi-component system, and hereinafter, the melting point or the pour point is collectively referred to as the melting point.

  According to the above configuration, since the melting point of the at least one evaporation prevention layer formed in the open-type heat storage container is equal to or higher than room temperature, a solid evaporation prevention layer is formed within the room temperature range, and the heat storage solution is excessive. Evaporation can be effectively prevented, and the heat storage solution can be prevented from leaking outside or being exposed to the air layer during transportation of the heat storage device. Further, even if the temperature of the heat storage solution rises during the heat storage operation, the evaporation prevention layer becomes a highly viscous liquid layer, so that not only can the excessive evaporation of the heat storage solution be effectively prevented, but also the pressure increase of the heat storage solution. It can respond enough. Therefore, any of the evaporation prevention function, the leakage prevention function, and the pressure relaxation function can be satisfied at the same time.

  In the heat storage device, the organic compound is preferably insoluble in the heat storage material. The melting point of the organic compound is preferably lower than the boiling point of the heat storage solution.

  According to the said structure, since the said organic compound is insoluble with respect to a thermal storage material, it can prevent effectively that an evaporation component permeate | transmits the said evaporation prevention layer compared with what melt | dissolves. Furthermore, since melting | fusing point is lower than the boiling point of a thermal storage solution, it can melt | dissolve reliably within the temperature range in which thermal storage operation | movement is performed. Therefore, the evaporation prevention function, the leakage prevention function, and the pressure relaxation function can be more reliably realized.

  In the heat storage device, at least one sub-evaporation prevention layer is further mixed with the evaporation prevention layer or formed as an independent layer below the evaporation prevention layer in the heat storage container, The sub-evaporation preventing layer is composed of a solvent composition comprising at least one water-insoluble solvent, and the melting point of the solvent composition is preferably less than room temperature.

  According to the above configuration, at least one sub-evaporation preventing layer is mixed with the evaporation preventing layer in the heat storage container, or is formed as an independent layer below the evaporation preventing layer. Therefore, the heat storage solution is protected by a plurality of “evaporation prevention layers”. In addition, during the heat storage operation, the evaporation prevention layer becomes a high viscosity liquid layer, and the sub-evaporation prevention layer is maintained as a relatively low viscosity liquid layer regardless of whether it is used or not used. The degree of adhesion increases. As a result, the vapor passage holes in each of these layers become narrower and the evaporation prevention function is improved compared to the case of using each of them alone, but the vapor of excess heat storage solution is released from each of these layers. Is possible. Further, after the heat storage operation, a crack generated after the evaporation prevention layer is cured can be filled with the sub-evaporation prevention layer. Therefore, the evaporation prevention function, the leakage prevention function, and the pressure relaxation function can be realized even more reliably.

  In the heat storage device, the specific gravity of the organic compound is more preferably smaller than the specific gravity of the solvent composition.

  According to the above configuration, since the specific gravity of the solvent composition constituting the sub-evaporation preventing layer is large, the upper layer of the sub-evaporation preventing layer is always used regardless of whether the organic compound as the main component of the evaporation preventing layer is solid or liquid. Will “float”. Therefore, even when the evaporation preventing layer becomes a liquid phase at a high temperature, it is possible to further prevent evaporation of the heat storage solution. In addition to this, the amount of the sub-evaporation preventing layer that is a liquid increases as it is located below the evaporation preventing layer. Therefore, after the heat storage operation, cracks generated after the evaporation prevention layer is cured can be filled with the sub-evaporation prevention layer even more reliably. As a result, it is possible to effectively suppress the heat storage solution from leaking to the air layer side during transportation of the heat storage device.

  In the heat storage device, the melting point of the solvent composition is more preferably lower than the freezing point of the heat storage solution.

  According to the said structure, even if temperature falls until a thermal storage solution solidifies, the said solvent composition can maintain fluidity | liquidity, Therefore Prevention of evaporation of a thermal storage solution can be implement | achieved effectively also in a low temperature state. In addition, since the solvent composition is not solidified even when the heat storage solution is solidified, it is possible to relieve the volume expansion associated with the solidification of the heat storage solution, thereby further reducing the pressure increase in the heat storage solution. It can be certain.

  In the heat storage device, it is more preferable that the solvent composition contains at least one of hydrocarbons having a carbon number in the range of 24 to 44 as the water-insoluble solvent.

  According to the said structure, since the said solvent composition contains the hydrocarbon which has the molecular weight of a specific range, the fluidity | liquidity maintenance at low temperature can be made more reliable. More desirably, the solvent composition further ensures fluidity retention at a low temperature if the main component thereof contains a hydrocarbon having a carbon number in the range of 24 to 44. Can do.

  In the said heat storage apparatus, although the specific structure of the said heat storage solution is not specifically limited, The example whose heat storage solution is the aqueous solution containing a bihydric alcohol can be mentioned preferably.

  According to the above configuration, since the heat storage solution is an aqueous solution containing not only water but also a dihydric alcohol, freezing can be avoided even when the heat storage solution is below the freezing point.

  The heat storage device may further include a heat source that heats the heat storage solution and a heat storage heat exchanger that recovers heat stored in the heat storage solution. Moreover, it is preferable that the heating source is provided outside the heat storage solution layer, and the heat storage heat exchanger is provided at a position immersed in the heat storage solution inside the heat storage container.

  According to the said structure, while providing a heat source, more suitable heat storage is attained, and by providing the heat exchanger for heat storage, the heat which stored heat can be collect | recovered suitably, and as a heat source, for example, heat storage If equipment having a function other than the heating function, such as a compressor located outside the solution layer, is used, the waste heat can be effectively stored and recovered.

  In the heat storage device, it is preferable that the heat storage container is provided so as to surround the heating source.

  According to the said structure, since the thermal storage container is located around a heating source, the heat from a heating source can be stored efficiently.

  In the heat storage device, it is preferable that the heat storage container is in contact with the heating source via a heat conductive member.

  According to the said structure, since the thermal storage container and the heating source are contacting via the heat conductive member, the heat from a heating source can be efficiently conducted to a thermal storage container.

  The heat storage device according to the present invention can be suitably used in any field for storing heat, but a typical example is an air conditioner. That is, the present invention includes an air conditioner including the heat storage device having the above-described configuration.

  As described above, according to the present invention, it is possible to provide a heat storage device that can stably hold a heat storage solution in a heat storage container and is excellent in handleability, and an air conditioner including the heat storage device.

(A) Schematic sectional view showing an example of the configuration of the heat storage device according to Embodiment 1 of the present invention, (b) In the heat storage solution layer and the evaporation prevention layer formed inside the heat storage device shown in (a), Schematic diagram showing changes in phase state with temperature change (A) Schematic sectional view showing an example of the configuration of the heat storage device according to the second embodiment of the present invention, (b) In the heat storage solution layer and the evaporation prevention layer formed inside the heat storage device shown in (a), Schematic diagram showing changes in phase state with temperature change (A) Cross-sectional view showing an example of the configuration of the heat storage device according to Embodiment 3 of the present invention, (b) Vertical cross-sectional view of the heat storage device shown in (a) The block diagram which shows an example of a structure of the air conditioning apparatus which concerns on Embodiment 4 of this invention. (A) Sectional drawing which shows an example of a structure of the conventional heat storage apparatus, Block diagram which shows an example of a structure of an air conditioning apparatus provided with the heat storage apparatus shown to (b) (a)

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference symbols throughout the drawings, and redundant description thereof is omitted. Details of the evaporation prevention function, leakage prevention function, and pressure relaxation function used in the text will be described later in (Details of Function).

(Embodiment 1)
[Configuration of heat storage device]
First, a specific configuration of the heat storage device according to the present embodiment will be specifically described with reference to FIG.

  As shown to Fig.1 (a), the thermal storage apparatus 20A which concerns on this Embodiment is provided with the thermal storage container 21 and the heat exchanger 22 for thermal storage, and the thermal storage solution is stored in the thermal storage container 21 by storing a thermal storage solution. A layer 11 is formed, and an evaporation preventing layer 13 and an air layer 12 are formed above the heat storage solution layer 11.

  The heat storage container 21 includes a box part 211 and a lid part 212. The box part 211 is a main body of the heat storage container 21, has a substantially rectangular parallelepiped shape, and has an upper opening 213 on its upper surface. The internal space of the box part 211 is configured to be able to store the heat storage solution layer 11, and the internal space is connected to the external space via the upper opening 213. The lid portion 212 is provided so as to cover the upper opening 213 of the box portion 211, and a ventilation hole 214 connected to the internal space of the box portion 211 is provided in a part thereof. Therefore, the internal space of the heat storage container 21 communicates with the outside air through the vent hole 214 even when the upper opening 213 of the box portion 211 is closed by the lid portion 212.

  The box part 211 and the cover part 212 only need to be made of a material and a shape that can stably hold the heat storage solution layer 11 in the internal space. Generally, the material is stainless steel (SUS) or fiber reinforced plastic. (FRP) is used, and the shape generally includes a rectangular parallelepiped shape or a cubic shape. Moreover, it does not specifically limit about the internal volume of the box part 211, What is necessary is just to design so that it may become an appropriate volume according to the use conditions etc. of 20 A of heat storage apparatuses.

The vent hole 214 provided in the lid portion 212 causes the internal air forming the air layer 12 to flow out of the heat storage container 21 or the steam generated from the heat storage solution in order to alleviate the pressure increase inside the heat storage container 21. It is configured to release dissolved air or the like to the outside. In addition, it is possible to prevent the air constituting the air layer 12 from flowing inside or outside the heat storage container 21 more than necessary, or the steam generated from the heat storage container 21 being released more than necessary to reduce the heat storage solution or the like. The opening area only needs to be optimized. The specific configuration such as the position, shape, and number of the vent holes 214 is not particularly limited as long as the configuration can realize relaxation of the pressure increase and suppression of decrease in the heat storage solution and the like. The vent hole 214 may be provided not on the lid portion 212 but on the upper portion of the box portion 211 or on both sides.

  As shown in FIG. 1, the heat storage heat exchanger 22 has a pipe-like configuration provided so as to spread over the entire interior of the heat storage container 21, and a heat medium for heat exchange (referred to as a heat exchange medium for convenience) inside. .) Is configured to be flowable. Further, the position where the heat storage heat exchanger 22 is provided is a position where the heat storage solution 21 is immersed in the heat storage container 21.

  The inlet part 221 and the outlet part 222 which are both ends of the heat storage heat exchanger 22 pass through the lid part 212 and are exposed to the outside from above the heat storage container 21, and these inlet part 221 and outlet part An external pipe for flowing the heat exchange medium is connected to 222. Moreover, the main body piping part 223 which constitutes most of the heat storage heat exchanger 22 is configured to be folded in a large part, and the main body piping part 223 extends from the inlet part 221 to the outlet part 222. The shape is unicursal. Most of the main body piping part 223 is immersed in the heat storage solution layer 11. Then, the heat exchange medium flows through the inside of the main body piping part 223 from the inlet part 221 toward the outlet part 222, whereby heat exchange is performed between the heat storage solution layer 11 and the heat exchange medium. The specific configuration of the heat storage heat exchanger 22 is not particularly limited, and a known configuration can be suitably used.

  The method of heat storage and heat recovery by the heat storage heat exchanger 22 is not particularly limited. For example, the following two methods can be used.

  First, the first method is a method of using the heat storage heat exchanger 22 as a heat radiation source. Specifically, the heat stored in the heat exchange medium is radiated to the heat storage solution layer 11 while a high-temperature heat exchange medium (for example, hot water or a high-temperature refrigerant) is circulated in the main body piping part 223. Thus, heat is stored in the heat storage solution layer 11. Although not shown in FIG. 1, a heat exchanger is provided separately from the heat storage heat exchanger 22, and a low-temperature heat exchange medium (for example, cold water or a low-temperature refrigerant) is circulated in the heat exchanger. Thus, heat is recovered from the heat storage solution layer 11.

  Next, in the second method, a heat supply device (a heat exchanger other than the heat storage heat exchanger 22 or a heat source) not shown in FIG. It is. Specifically, heat is stored in the heat storage solution layer 11 from the heat supply device, and a low-temperature heat exchange medium is circulated in the heat storage heat exchanger 22, thereby recovering heat from the heat storage solution layer 11 and storing heat. This is transmitted to a heat utilization device (not shown) connected to the outlet part 222 of the heat exchanger 22.

[Layer structure in heat storage container]
Next, the configuration of each layer formed in the heat storage container 21 will be specifically described with reference to FIG. As described above, the heat storage solution 11 is formed inside the heat storage container 21 by storing the heat storage solution. The heat storage solution layer 11 is stacked above the heat storage solution layer 11. Thus, the evaporation preventing layer 13 is formed. Further, the air layer 12 is formed above the evaporation preventing layer 13 by the outside air flowing from the vent holes 214. Therefore, the heat storage solution layer 11, the evaporation prevention layer 13, and the air layer 12 are formed in this order from the lower side inside the heat storage container 21.

The layer thicknesses of the heat storage solution layer 11 and the air layer 12 are not particularly limited, and are appropriate depending on various conditions such as the shape of the heat storage container 21, the volume of the internal space, and the volume increase of the heat storage solution due to thermal expansion. May be set. In other words, what is the value of the layer thickness of the heat storage solution layer 11 and the air layer 12 as long as a spatial margin (air layer 12) is formed so that the heat storage solution does not leak from the vent hole 214 due to thermal expansion? Also good.

  The heat storage solution constituting the heat storage solution layer 11 may be a heat storage medium (thermal-storage medium) composed of at least water. The heat storage solution may be composed only of water, but may contain various additives that can be dissolved or dispersed in water. In particular, in the present embodiment, it is preferable that a dihydric alcohol is contained as an antifreezing agent (antifreeze). If the heat storage solution is an aqueous solution containing a dihydric alcohol, freezing of the heat storage solution can be avoided even if it is below the freezing point (0 ° C. at normal temperature and normal pressure).

  The dihydric alcohol is not particularly limited, and examples thereof include ethylene glycol, propylene glycol, diethylene glycol, butanediol, neopentyl glycol, 3-methylpentadiol, 1,4-hexanediol, 1,6-hexanediol, and the like. Can be mentioned. Among these, ethylene glycol or propylene glycol is preferably used from the viewpoints of cost and actual use as an antifreezing agent. These dihydric alcohols may be used alone or in combination of two or more. Furthermore, the antifreezing agent is not limited to the dihydric alcohol, and may be a compound or composition other than the dihydric alcohol.

  Further, the specific type of additive added to the heat storage solution is not particularly limited, and besides the antifreezing agent, a supercooling inhibitor, a thickener, a heat transfer accelerator, a moisture evaporation inhibitor, and a corrosion inhibitor. Various additives known in the field of the heat storage material composition such as a rust preventive (when the heat storage container 21 is made of metal) can be used. The addition amount and addition method of these additives are not particularly limited, and a known range or method can be suitably used.

  The evaporation prevention layer 13 is laminated on the heat storage solution layer 11 and prevents or suppresses evaporation of the heat storage solution. The evaporation preventing composition constituting the evaporation preventing layer 13 is at least composed of an organic compound that is insoluble in the heat storage solution, has a specific gravity smaller than that of the heat storage solution, and has a melting point of room temperature or higher. The specific structure of the organic compound will be described later.

  Here, in the case of fats and oils whose melting point is unknown or a multicomponent system, it is synonymous with the pour point. The pour point is measured in accordance with Japanese Industrial Standard (JIS) K2269.

  Further, the evaporation preventing layer 13 imparts preferable physical properties for realizing an evaporation preventing function, a leakage preventing function, and a pressure relaxation function, which will be described later, or the evaporation preventing layer 13 is stably held in the heat storage container 21. In order to impart the above physical properties, other known components may be included in addition to the main component organic compound. Specifically, for example, antioxidants, corrosion inhibitors, rust inhibitors, pour point depressants, antifoaming agents, viscosity modifiers and the like can be exemplified. The addition amount and addition method of these additives are not particularly limited, and a known range or method can be suitably used.

  Therefore, both the heat storage solution layer 11 and the evaporation prevention layer 13 may be a composition prepared by preparing a plurality of components with a specific composition. In this case, the heat storage solution layer 11 is made of a heat storage solution composition containing water, and the evaporation prevention layer 13 is made of an evaporation prevention composition containing an organic compound as a main component. .

  Needless to say, even when the above-mentioned additives are included in the main organic compound as the evaporation preventing layer 13, the same effect can be obtained as long as the specific gravity and melting point conditions are satisfied.

[Composition of organic compound]
Next, the organic compound contained as the main component of the evaporation preventing layer 13 will be specifically described with an example.

  In the present embodiment, representative examples of the organic compound used as the evaporation preventing layer 13 include low-melting-point paraffins such as n-tricosane, n-docosane, and n-heneicosan, and alkene polymers such as polyethylene wax and polyolefin.

  The former low melting point paraffin n-tricosane has 23 carbons, melting point 46 ° C., specific gravity 0.7969, n-docosan has 22 carbons, melting point 46 ° C., specific gravity 0.7778, n-hencosan has 21 carbons, melting point 42 ° C. , A linear hydrocarbon having a specific gravity of 0.792. In addition, both are insoluble in the heat storage solution and have a small specific gravity, and the melting point is not more than the boiling point of the heat storage solution. The latter alkene polymer is obtained by polymerizing at least one alkene compound (an organic compound containing a double bond between carbon and carbon), and the melting point and the like are the structure, degree of polymerization, and molecular weight of the monomer. It depends on such things. Specifically, the alkene polymer has a structure represented by at least one of the following general formulas (1), (2), (3) and (4).

Here, each of R ¹ , R ² and R ^{3 in the} general formula is an organic group having 1 or more carbon atoms.

The specific type of the organic groups R ^{1 to} R ³ is not particularly limited as long as the alkene polymer is insoluble in the heat storage solution, has a specific gravity smaller than that of the heat storage solution, and has a melting point of room temperature or higher. Any known organic group may be used, but in general, the organic groups R ^{1 to} R ³ which are side chains are higher in linearity, and as desired in the present embodiment, evaporation is prevented. In order to further enhance the function, it is desirable that the alkene polymer has higher crystallinity. Therefore, the organic groups R ^{1 to} R ³ are more preferably linear organic groups.

Examples of linear organic groups include octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, icosyl, etc. A linear alkyl group of: phenylethyl group, phenylpropyl group, phenylbutyl group, phenylpentyl group, phenylhexyl group, phenylhebutyl group, 4-propyltolyl group, (1-ethyl-4-phenyl) propyl group, etc. Aromatic alkyl groups (including heterocyclic ring systems); linear alkylphenyl groups or linear alkylaromatic groups such as ethylphenyl group, propylphenyl group, butylphenyl group, pentylphenyl group, hexylphenyl group; octyloxy group, Nonyloxy, decyloxy, undecyloxy, dode Linear alkoxyl group such as ruoxy group, tridecyloxy group, octadecyloxy group, nonadecyloxy group; octenyl group, nonenyl group, decynyl group, undecynyl group, dodecynyl group, tridecynyl group, tetradecynyl group, pentadecynyl group, hexadecynyl group, heptadecynyl group Alkenyl groups such as octadecynyl group, nonadecynyl group, icosinyl group (position of double bond is not limited); alkanyl group (position of triple bond is not particularly limited); carboxyl group such as octanoyl group, noninoyl group, decinoyl group; Alkylamino groups such as N-octylamino group, N-nonylamino group and N-decylamino group; alkylamide groups such as dibutylamide group, butylpentylamide group and phenylethylamide group; dibutylphosphide group, butylpentyl Sufido group, alkyl phosphide groups such as phenylethyl phosphide group octyl sulfide group, Nonirusurufido group, an alkyl sulfide groups such as Deshirusurufido group; can be mentioned such as, but are not particularly limited. In the organic group, an arbitrary hydrogen atom may be substituted with a halogen atom, an arbitrary methyl group may be substituted with a silyl group, and when an oxygen atom or a sulfur atom is contained, The group 16 element may be substituted, or when a phosphorus atom is included, it may be substituted with another group 15 element. Furthermore, various side chain structures or cyclic structures may be included as long as there is little risk of hindering crystallinity or improvement in crystallinity is expected.

  The polymerization method (synthesis method) of the alkene polymer in the present embodiment is not particularly limited, and various known methods can be used. Here, the monomer used for the polymerization of the alkene polymer may include at least an alkene compound having a structure represented by the general formula (1), (2), (3) or (4), Of the structures represented by the general formulas (1), (2), (3), and (4), two types of alkene compounds may be included, and are represented by the general formulas (1) to (4). All alkene compounds having the structure described above may be included.

Moreover, only one type of monomer may be used, or two or more types may be used. For example, when the alkene compound used as a monomer is only a compound having a structure represented by the general formula (2) (vinyl compound), the organic group R ^{1 as} a substituent may be only one type, or a plurality of types A compound containing an organic group may be used in combination. That is, the alkene compound used in the general formula (2) may be only one specific type of vinyl compound or a plurality of types of vinyl compounds.

  Moreover, as a monomer, you may include monomer compounds other than the alkene compound represented by the said General Formula (1)-(4). In this case, the resulting polymer is a copolymer with alkene and other monomer compounds. The other monomer compound is not particularly limited as long as it is copolymerizable with an alkene compound such as (meth) acrylic acid ester, acrylonitrile, vinyl halide, and vinyl alcohol.

  In the polymerization of monomers, various catalysts, polymerization solvents, various additives, and the like may be used. For example, by preparing a monomer composition in which the catalyst, solvent, additive, etc. are prepared in any composition in the alkene compound, and polymerizing the monomer composition in any polymerization reactor under any conditions. The alkene compound in this embodiment can be produced.

  In addition, as an example of the polymerization method which can be used in the present embodiment, for example, a specific patent disclosed in Reference Patent Document: International Publication No. WO2002 / 014384 (corresponding Japanese Patent Publication: Special Table 2004-506758) And specific methods disclosed in the patent documents cited in the document (all of which are incorporated herein by reference), but are not particularly limited.

The resulting alkene polymer has a structure represented by the following general formula (5) or (6). In the general formula, R ¹ is an organic group as described above, X ¹ is a hydrogen atom or a substituent of R ² , and X ² is a hydrogen atom or a substituent of R ³ . Y in the general formula (6) is a divalent atom such as an oxygen atom or a sulfur atom, or a monomer structure other than an alkene compound. In addition, n, which is the number of repeating monomer structural units, may be an integer that can be appropriately selected within a preferable range of molecular weight.

Furthermore, since the monomer structural unit in a single polymer molecule only needs to correspond to the following general formula (5) or (6), the alkene polymer may be composed of only one type of structural unit, Multiple types of structural units may be included. That is, R ¹ , X ¹ , and X ² may be the same organic group or substituent in all monomer structural units in the same molecule, or different types of organic groups in each monomer structural unit in the same molecule. It may be a group or a substituent.

The molecular weight of the obtained alkene polymer is not particularly limited, but in the present embodiment, the number average molecular weight is preferably 1,000,000 or less. If the number average molecular weight is 1,000,000 or less, the melting point of the alkene polymer exceeds the normal temperature, and the solid is maintained at the normal temperature. Moreover, the temperature conditions (such as the allowable range of the melting point) of the alkene polymer obtained will be described later.

[Function of evaporation prevention layer]
Next, a specific function of the evaporation preventing layer 13 containing the organic compound will be specifically described with reference to FIG.

In the present embodiment, the evaporation prevention layer 13 is insoluble in the heat storage solution, has a specific gravity lighter than water, and contains at least the organic compound having a melting point equal to or higher than room temperature. It is solid.
Here, the semi-solid means a state corresponding to an intermediate between a solid and a liquid such as a heat-deformed state or a glass transition state.

  Regarding the heat storage solution layer 11 and the evaporation prevention layer 13, the change in the phase state from the solid phase to the liquid phase accompanying the temperature change is compared. As shown in FIG. 1B, if the temperature is low, any layer is solid or semi-solid (shaded area in the figure), but if the temperature is gradually increased, the heat storage solution layer 11 is The phase changes from a solid to a liquid at the freezing point Pf and is maintained in the liquid until the boiling point Pb is reached. On the other hand, the evaporation preventing layer 13 is solid or semi-solid at the freezing point Pf of the heat storage solution, and further remains solid or semi-solid even in the room temperature range (a region sandwiched by a one-dot chain line in the figure).

  The organic compound constituting the evaporation preventing layer 13 reaches the melting point Pm and is liquefied as a highly viscous liquid. In the present embodiment, the room temperature range is defined as a range of 20 ° C. ± 15 ° C. (5 ° C. or more and 35 ° C. or less) in accordance with Japanese Industrial Standard JIS Z 8703. Therefore, the melting point Pm of the organic compound only needs to exceed 35 ° C.

  If the temperature of the heat storage solution layer 11 further increases, when the boiling point Pb is reached, the heat storage solution boils and vaporization starts, but the evaporation prevention layer 13 is maintained as a highly viscous liquid. In addition, when the organic compound which comprises the evaporation prevention layer 13 is an alkene polymer etc., since it thermally decomposes, without vaporizing, when temperature becomes high enough, in FIG.1 (b), thermal decomposition temperature Pt is also illustrated. .

Thus, since the evaporation prevention layer 13 is solid or semi-solid within the range of normal temperature, excessive evaporation of the heat storage solution can be effectively prevented (realization of the evaporation prevention function), and heat storage is performed during transportation of the heat storage device 20A. It can suppress that the thermal storage solution which comprises the solution layer 11 leaks out of the thermal storage container 21, or is exposed to the air layer 12 (realization of a leakage prevention function). Even if the temperature of the heat storage solution rises during the heat storage operation, the evaporation preventing layer 13 becomes a high-viscosity liquid layer, so that excessive evaporation of the heat storage solution can be effectively prevented.

  Furthermore, even if the vapor pressure rises due to evaporation of the heat storage solution or a gas such as dissolved oxygen contained in the heat storage solution is liberated, the evaporation prevention layer 13 is a highly viscous liquid. Even if the swells, the upper surface thereof is satisfactorily covered with the evaporation preventing layer 13. Moreover, even if the pressure rises greatly, a part of the vapor or free gas escapes from the liquid evaporation preventing layer 13 to the air layer 12, so that the pressure does not rise excessively and is sufficient for increasing the pressure of the heat storage solution. It can respond (realization of pressure relief function). Therefore, any of the evaporation prevention function, the leakage prevention function, and the pressure relaxation function can be realized satisfactorily. As a result, the heat storage solution can be stably held in the heat storage container 21, and the heat storage device 20 </ b> A excellent in handleability can be obtained.

  In the present embodiment, the melting point Pm of the organic compound used as the evaporation preventing layer 13 is preferably lower than the boiling point Pb of the heat storage solution. In the present embodiment, since the aqueous solution is used as the heat storage solution, the boiling point Pb is substantially 100 ° C. Accordingly, the melting point Pm of the organic compound is preferably 35 ° C. or more and less than 100 ° C. Thereby, in an organic compound, since melting | fusing point is lower than the boiling point of a thermal storage solution, it can melt | dissolve reliably within the temperature range in which thermal storage operation | movement is performed. Therefore, any of the evaporation prevention function, the leakage prevention function, and the pressure relaxation function can be realized satisfactorily.

  As an example of a particularly preferred alkene polymer in the present embodiment, a polymer having 18 carbon atoms using an alkene compound as a monomer can be exemplified. If this polymer is used as the evaporation preventing layer 13, the physical properties of the evaporation preventing layer 13 are further stabilized since the alkene polymer contains polyalphaolefin having a specific range of 18 carbon atoms. Therefore, any of the evaporation prevention function, the leakage prevention function, and the pressure relaxation function can be realized satisfactorily.

  Further, if the evaporation prevention layer 13 is composed of the above-described organic compound as a main component, the evaporation prevention layer 13 can be formed only by being laminated on the heat storage solution layer 11, and a large amount of organic acid is present. It is possible to suppress the possibility that the quality of the heat storage solution is deteriorated. Therefore, it is possible to avoid an increase in manufacturing cost or maintenance cost of the heat storage device 20A.

(Embodiment 2)
The heat storage device 20A in the first embodiment has a configuration in which three layers of the heat storage solution layer 11, the evaporation prevention layer 13, and the air layer 12 are formed in order from the bottom in the heat storage container 21. In the present embodiment, one or more sub-evaporation preventing layers are further provided between the heat storage solution layer 11 and the evaporation preventing layer 13. The configuration will be specifically described with reference to FIGS. 2 (a) and 2 (b).

[Layer structure in heat storage container]
As shown in FIG. 2A, the heat storage device 20B according to the present embodiment has the same configuration as the heat storage device 20A according to the first embodiment. The four layers of the heat storage solution layer 11, the sub-evaporation prevention layer 14, the evaporation prevention layer 13, and the air layer 12 are formed in order.

The sub-evaporation prevention layer 14 is a layer that prevents or suppresses evaporation of the heat storage solution that constitutes the heat storage solution layer 11 together with the evaporation prevention layer 13 (implements an evaporation prevention function). In this embodiment, the evaporation prevention layer 13 is used. Is formed as an independent layer below. Although not shown in FIG. 2A, the sub-evaporation preventing layer 14 may be mixed with the evaporation preventing layer 13 to be substantially one layer. The sub-evaporation preventing layer 14 is composed of a solvent composition composed of at least one water-insoluble solvent. As the solvent composition, as will be described later, for example, 85 to 95% by weight is a water-insoluble solvent, and the remaining part is preferably composed of a mixture of additives such as antioxidants. .

  When two or more sub-evaporation prevention layers 14 are formed, each of the sub-evaporation prevention layers 14 may be composed of a solvent composition having a different composition and may be formed independently without being mixed with each other. Alternatively, the sub-evaporation preventing layers 14 may be mixed with each other or may be mixed with the evaporation preventing layer 13.

  The water-insoluble solvent used in the solvent composition is a nonpolar solvent having substantially no polarity, low polarity that is low in polarity so that it becomes a single layer released from the aqueous layer without being substantially mixed with water at room temperature. What is necessary is just to show a liquid at least within the range of normal temperature, such as a solvent.

  Specific examples of the water-insoluble solvent include saturated alkanes such as pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, and cyclohexane; toluene, xylene, Aromatic alkanes such as benzene; haloalkanes such as 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, carbon tetrachloride, methylene chloride (dichloromethane); methyl acetate, ethyl acetate, acetic acid Esters such as isopropyl; Ethers such as diethyl ether, isopropyl ether, ethyl tert-butyl ether and furan; Mineral oils such as polyalphaolefin wax, paraffin wax and silicone oil Corn oil, soybean oil, sesame oil, rapeseed oil, rice oil, coconut oil, safflower oil, palm kernel oil, coconut oil, cottonseed oil, sunflower oil, sesame oil, olive oil, peanut oil, almond oil, grape seed oil, mustard oil, fish oil Edible oils and fats; industrial fats and oils such as castor oil and oilseed oil; but not limited thereto. These water-insoluble solvents may be used alone or in combination of two or more. Moreover, when a solvent composition contains multiple types of water-insoluble solvent, if the effective evaporation prevention function is realizable, the composition of each solvent will not be specifically limited, either.

  In the present embodiment, as an example of a particularly preferable water-insoluble solvent, the silicone oil, the saturated alkanes, the aromatic alkanes, etc. (or a chain or alicyclic chain that is close to the saturated alkanes without limitation) Among hydrocarbons of hydrocarbons (hereinafter referred to as saturated alkanes), at least any one of hydrocarbons having a carbon number in the range of 24 to 44 can be mentioned, and more specifically, Examples thereof include polyalphaolefin wax or paraffin wax containing a component having a carbon number within the range.

  The fact that the solvent composition contains such a water-insoluble solvent means that the solvent composition contains a hydrocarbon having a specific range of molecular weight. Therefore, as will be described later, the fluidity retention of the sub-evaporation preventing layer 14 at a low temperature can be made more reliable. More desirably, the solvent composition further ensures fluidity retention at a low temperature if the main component thereof contains a hydrocarbon having a carbon number in the range of 24 to 44. Can do.

The carbon structure of the water-insoluble solvent will be described. Generally speaking, saturated alkanes (also called saturated hydrocarbons) are gases at room temperature when the carbon number is 4 or less, liquid at room temperature with 5 to about 18 carbon atoms, and room temperature when the carbon number exceeds about 18 It is solid. The regularity of this general theory is a story that consists of saturated alkanes of straight-chain structure in which the carbon is arranged in a straight line and has no branches. When saturated alkanes with branches are used, the carbon number exceeds about 18. Also becomes liquid at room temperature. Therefore, for example, when an α-olefin having 8 to 10 carbon atoms (unsaturated alkene having a double bond at the terminal and others having a single bond structure) is subjected to a polymerization reaction and then hydrotreated, the carbon number is within the range of 24 to 44. Saturated alkanes containing at least one of the hydrocarbons in (1) are produced. In addition, since these saturated alkanes are saturated alkanes having many branches by devising the polymerization reaction, they are liquid at room temperature. Mineral oils, synthetic oils, and semi-synthetic oils used in the present embodiment are mixed with a water-insoluble solvent obtained by using this production method in an amount of 85 to 100% by weight (% by weight).

  Such hydrocarbons with a carbon number in the numerical range are often left to the control because it is difficult to control the carbon number with current technology. Therefore, when it becomes a hydrocarbon having less than 24 carbon atoms, it is likely to be a saturated alkane having a linear structure, so that a highly volatile liquid is generated, which is immediately volatilized and has a short life. On the other hand, when the hydrocarbon has 45 or more carbon atoms, it is difficult to handle because it tends to become solid at room temperature. Thus, the water-insoluble solvent contains at least one of hydrocarbons having a carbon number in the range of 24 to 44 because it is difficult to volatilize, has a long life, is liquid at room temperature, and is easy to handle. It was set as the composition which was supposed to be. In addition to this, this water-insoluble solvent has an advantage that it is difficult to produce an organic acid and is highly airtight, so that evaporation of the heat storage solution is prevented or suppressed, and oxygen in the air is difficult to enter the heat storage solution. .

  Furthermore, the solvent composition may contain other known components in addition to the water-insoluble solvent. Specifically, an antioxidant, a corrosion inhibitor, a rust inhibitor, an antifoaming agent, etc. can be illustrated, for example. The addition amount and addition method of these additives are not particularly limited, and a known range or method can be suitably used.

  Although the specific composition of the solvent composition is not particularly limited, in the present embodiment, as described above, at least one water-insoluble solvent is in the range of 85 to 95% by weight, and the additive is added. The structure which the mixture to contain is the remainder (within the range of 5 to 15 weight%) can be mentioned preferably. Of course, it goes without saying that the composition can be appropriately designed according to various conditions such as the performance required for the sub-evaporation prevention layer 14 and the usage environment of the heat storage device 20A.

  The temperature condition of the solvent composition is not particularly limited, but it is preferable that the solvent composition is liquid within the range of normal temperature, and therefore the melting point is preferably less than normal temperature. Moreover, as described later, the melting point of the solvent composition is preferably lower than the freezing point of the heat storage solution.

[Function of sub-evaporation prevention layer]
Next, a specific function of the sub-evaporation preventing layer 14 containing the water-insoluble solvent will be specifically described with reference to FIG.

  Regarding the heat storage solution layer 11, the evaporation preventing layer 13, and the sub-evaporation preventing layer 14, the change in the phase state from the solid phase to the liquid phase accompanying the temperature change is compared. As shown in FIG. 2 (b), the phase change of the heat storage solution layer 11 and the evaporation preventing layer 13 is as described in the first embodiment, but the sub-evaporation preventing layer 14 is shown in FIG. 2 (b). In the example shown, even if it is within the range of normal temperature or exceeds normal temperature, it remains substantially liquid.

Thus, within the range of normal temperature, the sub-evaporation prevention layer 14 is a liquid, but the evaporation prevention layer 13 is a solid. Therefore, the evaporation prevention layer 13 can realize an evaporation prevention function for the heat storage solution, and the heat storage solution and A leakage prevention function can be realized for the sub-evaporation prevention layer 14. Further, when the temperature of the heat storage solution rises during the heat storage operation, the evaporation prevention layer 13 becomes a high viscosity liquid layer, and the sub-evaporation prevention layer 14 is maintained as a relatively low viscosity liquid layer regardless of use or non-use. Therefore, the heat storage solution is protected by the two liquid layers, and the adhesion between the liquid layers increases.

  As a result, in these layers, the vapor passage holes are narrowed and the function of preventing evaporation is improved, but the excess heat storage solution vapor or dissolved oxygen is released in these layers as compared with the case where each is used alone. (Improvement of pressure relaxation function). In addition, after the heat storage operation, a crack generated after the evaporation prevention layer 13 is cured can be filled with the sub-evaporation prevention layer 14 (improvement of the evaporation prevention function and the leakage prevention function).

  Moreover, as shown in FIG.2 (b), melting | fusing point Pp of a solvent composition is lower than the freezing point Pf of a thermal storage solution. Thereby, even if the temperature of the heat storage device 20B is decreased until the heat storage solution is solidified, the solvent composition can maintain fluidity, so that the evaporation preventing function can be effectively realized even in a low temperature state. Further, since the solvent composition is not solidified even when the heat storage solution is solidified, it is possible to relieve the volume expansion associated with the solidification of the heat storage solution, and the pressure relaxation function can be further ensured. In particular, if the solvent composition contains a hydrocarbon having a carbon number in the range of 24 to 44, the fluidity at a low temperature of the sub-evaporation preventing layer 14 can be better maintained.

  As described above, the sub-evaporation prevention layer 14 is formed in the heat storage container 21 in addition to the evaporation prevention layer 13, so that any of the evaporation prevention function, the leakage prevention function, and the pressure relaxation function by the evaporation prevention layer 13 is good. In addition, the functions can be further improved. Therefore, the heat storage solution can be stably held in the heat storage container 21, and the heat storage device 20B excellent in handleability can be obtained.

  In addition, it is preferable that the specific gravity of the organic compound (or the evaporation preventing composition containing the same) constituting the evaporation preventing layer 13 is smaller than the specific gravity of the solvent composition constituting the sub-evaporation preventing layer 14. As a result, the evaporation preventing layer 13 is lighter than the sub-evaporation preventing layer 14 even if the organic compound as the main component is solid, so that the evaporation preventing layer 13 must always “float” above the sub-evaporation preventing layer 14. become. Therefore, even if the evaporation preventing layer 13 becomes a liquid phase at a high temperature, the evaporation preventing function can be further ensured.

  In addition to this, the amount of the sub-evaporation prevention layer 14 that is a liquid increases as it is located below the evaporation prevention layer 13. Therefore, after the heat storage operation, cracks that occur after the evaporation preventing layer 13 is cured can be more reliably filled with the sub-evaporation preventing layer 14. As a result, the evaporation prevention function and the leakage prevention function can be further improved. At this time, for example, when both the evaporation prevention layer 13 and the sub-evaporation prevention layer 14 are very easy to mix and are integrated at a high temperature, it becomes a solid when returning to room temperature after the heat storage operation. The sub-evaporation preventing layer 14 is partially taken into the evaporation preventing layer 13, but the sub-evaporation preventing layer 14 has higher specific gravity. It becomes solid, gel, and liquid. In this case, even if the lowermost layer is a gel, the effect of filling the cracks against the cracks can be seen, but in order to exert the effect more effectively, if the ratio of the sub-evaporation prevention layer 14 to the evaporation prevention layer 13 is increased, Since the amount of liquid in the lowermost layer is increased, the ratio of the evaporation preventing layer 13 and the sub-evaporation preventing layer 14 is preferably designed in consideration of the amount of liquid in the lowermost layer remaining at normal temperature.

  Furthermore, the evaporation prevention layer 13 and the sub-evaporation prevention layer 14 can be easily formed by simply laminating on the heat storage solution layer 11, and the evaporation prevention layer 13 is mainly composed of an alkene polymer as described above. Therefore, it is possible to suppress the possibility that a large amount of organic acid is generated and the quality of the heat storage solution is deteriorated. Therefore, an increase in manufacturing cost or maintenance cost of the heat storage device 20B can be avoided.

(Embodiment 3)
The heat storage device 20A according to the first embodiment or the heat storage device 20B according to the second embodiment each includes the heat storage container 21 and the heat exchanger 22 for heat storage, but the heat storage according to the present embodiment. The apparatus further includes a heating source, and is configured to be able to store the waste heat of the heating source. This configuration will be specifically described with reference to FIGS. 3 (a) and 3 (b).

  As shown to Fig.3 (a) and (b), in addition to the thermal storage container 23 and the heat exchanger 24 for thermal storage, the thermal storage apparatus 20C which concerns on this Embodiment is compression as a heat conductive member 25 and a heating source. A machine 26 is provided. In addition, the V1-V1 arrow cross section in Fig.3 (a) is equivalent to the longitudinal cross-sectional view of 20 C of heat storage apparatuses shown in FIG.3 (b), and the V2-V2 arrow cross section in FIG.3 (b) is FIG.3 (a). This corresponds to a cross-sectional view of the heat storage device 20C shown in FIG.

  Like the heat storage container 21 in the first embodiment, the heat storage container 23 includes a box portion 231 and a lid portion 232, and a lid portion 232 is attached so as to close the upper opening 233 of the box portion 231. The shape of the box portion 231 is substantially a rectangular parallelepiped shape, similar to the box portion 211 in the first or second embodiment, but the shape of the internal space for storing the heat storage solution is the same as that of the box portion 211. In contrast, as shown in FIG. 2A, it has a substantially U-shaped cross section so as to surround the side surface of the compressor 26. As shown in FIG. 2B, a heat storage heat exchanger 24 is provided inside the box portion 231, and the heat storage solution layer 11 is formed so as to immerse most of the heat exchanger 24. Further, the sub-evaporation prevention layer 14 and the evaporation prevention layer 13 are laminated in this order above the heat storage solution layer 11, and further, above the evaporation prevention layer 13, through a vent hole 234 provided in the lid 232. An air layer 12 is formed by the outside air flowing in.

  The compressor 26 compresses the refrigerant used in the air conditioner, and a compressor having a known configuration is used. 3A and 3B, for convenience of explanation, the compressor 26 schematically shows only the outer shape. In the present embodiment, the compressor 26 has an approximately rectangular parallelepiped shape as shown in FIGS. 3A and 3B, and surrounds three of the four side surfaces of the rectangular parallelepiped shape. The heat storage container 23 is located in the area. Since the internal space of the heat storage container 23 (box portion 211) has a substantially U-shaped cross section as described above, the compressor 26 is positioned in a region where the recessed portion is located in the U-shaped cross section. As a result, at least a part of the periphery of the compressor 26 is surrounded by the heat storage container 23.

  Thus, if the heat storage container 23 is located around the compressor 26, the compressor 26 is substantially integrated with the heat storage container 23, so that the waste heat generated in the compressor 26 is stored in the heat storage container 23. Almost no escape to the outside is transmitted to the heat storage solution layer 11 in the heat storage container 23. Therefore, the compressor 26 which is an external device can be used as a heating source, and waste heat from the compressor 26 can be efficiently stored.

  Here, it is particularly preferable that a layered heat conductive member 25 is provided between the side surface of the compressor 26 and the heat storage container 23. The compressor 26 may be in direct contact with the heat storage solution layer 11 in the heat storage container 23, but in this case, it is necessary to waterproof the side surface of the compressor 26. On the other hand, the shape of the heat storage container 23 may be configured to match the compressor 26 and have a substantially U-shaped cross section, but in addition to the processing of the heat storage container 23 becoming complicated and the cost rising, It becomes difficult to improve the adhesion between the outer surface of the heat storage container 23 and the side surface of the compressor 26. Therefore, it is preferable to provide the heat conductive member 25 as in the present embodiment.

  The specific configuration of the heat conductive member 25 is not particularly limited as long as it can cover the periphery of the compressor 26 and can transfer the heat from the compressor 26 to the heat storage solution layer 11 in a good manner. . Specifically, for example, a metal sheet formed of copper, silver, aluminum, or an alloy thereof; a heat conductive sheet in which graphite or metal particles are dispersed in a resin composition; a graphite or metal particle in a gel composition Heat conductive grease dispersed in the material.

  Thus, the heat storage container 23 is in contact with the compressor 26 via the heat conductive member 25, so that the heat from the compressor 26 can be recovered well by the heat storage device 20C. In particular, if the heat conductive member 25 is a heat conductive sheet, if a flexible material, for example, an elastomer material such as EPDM (ethylene-propylene-diene rubber) or silicone rubber is selected as the resin composition, the compressor 26 Even if unevenness is present on the side surface, the contact between the compressor 26 and the heat storage container 23 can be improved, so that the heat conduction from the compressor 26 to the heat storage container 23 is made even smoother. Can do.

  Also in the present embodiment, the evaporation preventing layer 13 and the sub-evaporation preventing layer 14 described in the first and second embodiments are formed in the heat storage container 23. Therefore, the evaporation prevention function, the leakage prevention function, and the pressure relaxation function are all realized satisfactorily by these layers, so that the heat storage solution can be stably held in the heat storage container 23, thereby improving handling. An excellent heat storage device 20C can be obtained.

  In addition, in this Embodiment, although the compressor 26 was illustrated as a heating source, it is not limited to this, It is not limited to this, It is another heating source with which the apparatus with which heat storage apparatus 20C which concerns on this invention is applied, such as an air conditioning apparatus. There may be. Moreover, the heat source should just be provided in the exterior of the thermal storage solution layer 11, and does not necessarily need to be the exterior of the thermal storage container 23. FIG. Further, the heat source may not be surrounded by the heat storage container 23. For example, as long as the compressor 26 has a wide flat side surface, the thermal storage solution layer 11 may be configured only to contact the flat surfaces. Moreover, in this Embodiment, although the thermal storage container 23 has enclosed the circumference | surroundings of the compressor 26, you may surround the bottom face or upper surface of the compressor 26, for example. The same applies if the heating source is other than the compressor 26.

(Embodiment 4)
The first to third embodiments exemplify the configuration of the heat storage device, but in the present embodiment, an example of an air conditioner that is a typical application example of the heat storage device having the above configuration. This will be specifically described with reference to FIG.

[Configuration of air conditioner]
As shown in FIG. 4, the air conditioner 30 according to the present embodiment includes an indoor unit 31 and an outdoor unit 32 that are connected to each other by a refrigerant pipe, and the outdoor unit 32 is the same as that of the third embodiment. This heat storage device 20C is provided. The indoor unit 31, the outdoor unit 32, and the external pipe 310 are connected to the indoor unit internal pipe 311 and the first pipe 301 and the second pipe 302 that are the outdoor unit internal pipes through the pipe joint 40.

  Inside the indoor unit 31, an indoor unit internal pipe 311 and an indoor heat exchanger 33 are provided. Inside the outdoor unit 32, the heat storage device 20C, the compressor 26, the outdoor unit internal pipe, and the outdoor heat exchanger 34 are provided. Various valve members and the like are provided. And since the indoor unit 31 and the outdoor unit 32 are mutually connected by the external piping 310 as above-mentioned, the refrigerating cycle of the air conditioning apparatus 30 is comprised by the said structure. In the following description, in the refrigerant pipe (the indoor unit internal pipe 311, the external pipe 310, and the outdoor unit internal pipe), the upstream side or the downstream side in the direction in which the refrigerant flows is simply abbreviated as the upstream side or the downstream side.

  The configuration of the indoor unit 31 will be specifically described. The indoor unit internal pipe 311 connected to the external pipe 310 is connected to the indoor heat exchanger 33. In addition to the indoor heat exchanger 33, an air blower fan (not shown), upper and lower blades (not shown), left and right blades (not shown), and the like are provided inside the indoor unit 31.

  The indoor heat exchanger 33 exchanges heat between the indoor air sucked into the indoor unit 31 by the blower fan and the refrigerant flowing inside the indoor heat exchanger 33, and was heated by heat exchange during heating. While air is blown into the room (block arrow in the figure), air cooled by heat exchange is blown into the room during cooling. The upper and lower blades change the direction of air blown from the indoor unit 31 up and down as necessary, and the left and right blades change the direction of air blown from the indoor unit 31 to right and left as needed. In FIG. 4, for the convenience of explanation, the detailed configuration of the indoor unit 31 (the blower fan, the upper and lower blades, the left and right blades, etc.) is omitted.

  The configuration of the outdoor unit 32 will be specifically described. In addition to the compressor 26, the heat storage device 20C, and the outdoor heat exchanger 34, the outdoor unit 32 includes a strainer 35, an expansion valve 42, a four-way valve 41, a first An electromagnetic valve 43, a second electromagnetic valve 44, an accumulator 36, and the like are provided. Of the first pipe 301 and the second pipe 302 connected to the external pipe 310, the first pipe 301 is connected to a discharge port (not shown) of the compressor 26. Therefore, the compressor 26 is connected to the indoor heat exchanger 33 in the indoor unit 31.

  As described in the third embodiment, the compressor 26 is provided so as to be substantially integrated with the heat storage container 23 of the heat storage device 20C, and the periphery of the compressor 26 includes the heat conductive member 25. The heat storage solution layer 11 is located through. A sub-evaporation preventing layer 14 and an evaporation preventing layer 13 are formed in this order on the upper surface of the heat storage solution layer 11. In FIG. 4, for convenience of explanation, the description of the lid 232 and the air layer 12 constituting the heat storage container 23 is omitted. Inside the heat storage container 23, a heat storage heat exchanger 24 is provided so as to be immersed in the heat storage solution layer 11, and an inlet (not shown) is connected to the sixth pipe 306. The sixth solenoid valve 44 is provided in the sixth pipe 306.

  Of the first pipe 301 and the second pipe 302 connected to the external pipe 310, the second pipe 302 is branched into a third pipe 303 and a sixth pipe 306 that are outdoor unit internal pipes. The second pipe 302 includes the strainer 35, and as described above, one is connected to the external pipe 310 and the other is connected to the third pipe 303 through the expansion valve 42. The sixth pipe 306 is branched from the second pipe 302 on the upstream side of the strainer 35.

  The third pipe 303 connects the expansion valve 42 and the outdoor heat exchanger 34, and the outdoor heat exchanger 34 is connected to the suction port (not shown) of the compressor 26 via the fourth pipe 304. Further, an accumulator 36 for separating the liquid-phase refrigerant and the gas-phase refrigerant is provided on the fourth pipe 304 on the compressor 26 side. The discharge port of the compressor 26 is connected to the first pipe 301, and the fifth pipe 305 branches from between the discharge port of the compressor 26 and the four-way valve 41 in the first pipe 301. ing. A first electromagnetic valve 43 is provided in the fifth pipe 305. The first pipe 301 is connected between the expansion valve 42 of the third pipe 303 and the outdoor heat exchanger 34 via the fifth pipe 305.

  The sixth pipe 306 branched from the second pipe 302 is connected to the inlet part (not shown) of the heat storage heat exchanger 24 as described above, but the outlet part ( (Not shown) is connected to the fourth pipe 304 via the seventh pipe 307. The seventh pipe 307 branches from the fourth pipe 304 at a position upstream from the accumulator 36.

  Further, an intermediate portion between the first pipe 301 and the fourth pipe 304 is connected by a four-way valve 41. Specifically, in the first pipe 301, the four-way valve 41 is provided on the upstream side from the position where the fifth pipe 305 branches, and in the fourth pipe 304, on the upstream side from the position where the seventh pipe 307 branches. A four-way valve 41 is provided at a position downstream from the position connected to the outdoor heat exchanger 34.

  Here, among the outdoor unit internal pipes, the fourth pipe 304 constitutes a heat pump circulation path, and the fifth pipe 305 and the sixth pipe 306 constitute a refrigerant bypass path. That is, the air conditioning apparatus 30 according to the present embodiment has a heat pump type configuration. With this configuration, the heating operation can be performed non-stop in parallel with the defrosting operation, as will be described later. This point will be described later.

  Each device or member (refrigerant pipe, pipe joint 40, indoor heat exchanger 33, blower fan, upper and lower blades, left and right blades, outdoor heat exchanger 34, strainer 35, expansion valve 42, excluding the compressor 26 and the heat storage device 20C. The specific configuration of the four-way valve 41, the first electromagnetic valve 43, the second electromagnetic valve 44, the accumulator 36, etc.) is not particularly limited, and a known configuration can be suitably used. Further, the number of devices and members including the compressor 26 and the heat storage device 20C, the arrangement, and the like are not limited to the configuration illustrated in FIG. 4, and other arrangements capable of realizing a heat pump configuration may be used.

  The compressor 26, the blower fan, the upper and lower blades, the left and right blades, the four-way valve 41, the expansion valve 42, the first electromagnetic valve 43, the second electromagnetic valve 44, and the like are electrically connected to a control device (not shown, for example, a microcomputer). Connected to each other and controlled by the control device.

[Operation of air conditioner]
Next, the operation of the air-conditioning apparatus 30 having the above-described configuration will be specifically described with reference to FIG. 4 by taking normal heating operation and defrosting / heating operation as examples.

  First, the normal heating operation will be described. In this case, the first electromagnetic valve 43 and the second electromagnetic valve 44 are controlled to be closed, and the refrigerant discharged from the discharge port of the compressor 26 flows through the first pipe 301 and flows from the four-way valve 41 to the external pipe 310 and the indoors. It reaches the indoor heat exchanger 33 via the machine internal pipe 311. In the indoor heat exchanger 33, the refrigerant condenses by heat exchange with room air. The refrigerant flows from the indoor heat exchanger 33 through the second pipe 302 to the expansion valve 42 and is decompressed by the expansion valve 42. The decompressed refrigerant reaches the outdoor heat exchanger 34 through the third pipe 303. In the outdoor heat exchanger 34, the refrigerant evaporates due to heat exchange with outdoor air, and this refrigerant flows through the fourth pipe 304 and returns from the four-way valve 41 to the suction port of the compressor 26. The heat (waste heat) generated in the compressor 26 is accumulated in the heat storage solution layer 11 in the heat storage container 23 from the outer wall of the compressor 26 via the heat conductive member 25.

  Next, defrosting / heating operation will be described. When the frost is generated in the outdoor heat exchanger 34 during the normal heating operation and further the frost is grown, the ventilation resistance of the outdoor heat exchanger 34 is increased and the air volume is decreased, so that the inside of the outdoor heat exchanger 34 is reduced. The evaporation temperature of the liquid drops. Therefore, when a temperature sensor (not shown) for detecting the piping temperature of the outdoor heat exchanger 34 detects that the evaporation temperature has decreased as compared with the time of non-frosting, the controller performs the defrosting / heating from the normal heating operation. An instruction to drive is output.

  When the normal heating operation is shifted to the defrosting / heating operation, the first electromagnetic valve 43 and the second electromagnetic valve 44 are controlled to open, and in addition to the refrigerant flow during the normal heating operation described above, the first electromagnetic valve 43 and the second electromagnetic valve 44 are discharged from the discharge port of the compressor 26. Part of the vapor-phase refrigerant flows through the fifth pipe 305 and the first electromagnetic valve 43, joins the refrigerant flowing through the third pipe 303, heats the outdoor heat exchanger 34, and condenses into a liquid phase. Thereafter, it flows through the fourth pipe 304 and returns to the suction port of the compressor 26 via the four-way valve 41 and the accumulator 36.

Further, a part of the liquid-phase refrigerant that is divided between the indoor heat exchanger 33 and the strainer 35 in the second pipe 302 is stored in the heat storage heat exchanger 24 via the sixth pipe 306 and the second electromagnetic valve 44. By absorbing heat from the solution layer 11, it is evaporated and vaporized. The gas phase refrigerant flows through the seventh pipe 307, joins the refrigerant flowing through the fourth pipe 304, and returns from the accumulator 36 to the suction port of the compressor 26.

  The refrigerant that returns to the accumulator 36 includes liquid phase refrigerant that returns from the outdoor heat exchanger 34, and this liquid phase refrigerant is mixed with high-temperature gas-phase refrigerant that returns from the heat storage heat exchanger 24. The evaporation of the liquid phase refrigerant is promoted, the liquid phase refrigerant is prevented from returning to the compressor 26 through the accumulator 36, and the reliability of the compressor 26 can be improved.

  The temperature of the outdoor heat exchanger 34 that has become below freezing due to the attachment of frost at the start of defrosting and heating is heated by the gas-phase refrigerant discharged from the discharge port of the compressor 26, and the frost is melted at around zero degrees. When the frost has finished melting, the temperature of the outdoor heat exchanger 34 begins to rise again. If the temperature sensor detects the temperature increase of the outdoor heat exchanger 34, the control device determines that the defrosting is completed, and the control device outputs an instruction from the defrosting / heating operation to the normal heating operation. .

  Thus, in this Embodiment, since the air conditioning apparatus 30 is a heat pump type, even if frost formation has arisen in the outdoor heat exchanger 34 at the time of heating operation or in winter, it is a refrigerant | coolant bypass path. Refrigerant can be collected and defrosted by flowing a refrigerant through certain fifth pipe 305 and sixth pipe 306. Therefore, since the heating operation can be performed in parallel with the defrosting operation, for example, even in a cold morning in winter, the heating can be performed in a short time. In addition, since waste heat from the compressor 26 can be effectively recovered, an energy saving operation is possible.

  Further, as described in the third embodiment, the heat storage device 20C effectively prevents excessive evaporation of the heat storage solution because the evaporation prevention layer 13 and the sub-evaporation prevention layer 14 are formed in the heat storage container 23. In addition to being able to achieve (realization of the evaporation prevention function), it is possible to suppress the heat storage solution from leaking out of the heat storage container 21 or being exposed to the air layer 12 (realization of the leakage prevention function), and further, the pressure of the heat storage solution layer 11 Even if the temperature rises greatly, a part of the vapor or free gas escapes from the liquid evaporation preventing layer 13 to the air layer 12, so that the pressure does not rise excessively and can sufficiently cope with the pressure rise of the heat storage solution. (Pressure relaxation function can be realized).

  In addition, in this Embodiment, although the air conditioning apparatus 30 becomes a heat pump type structure, it is not limited to this, and it cannot be overemphasized that structures other than a heat pump type may be sufficient. Further, in place of the heat storage device 20C, the heat storage device 20A or 20B described in the first or second embodiment may be provided, or a heat storage device having another configuration within the scope of the present invention may be provided. Furthermore, in this Embodiment, although the compressor 26 is used as a heat source, you may use other apparatuses, such as an electric heater, as a heat source.

  Furthermore, in this Embodiment, although the air conditioning apparatus was illustrated as an example which applies heat storage apparatus 20A-20C which concerns on this invention, of course, this invention is not limited to this, A heat storage apparatus is provided other than an air conditioning apparatus. It can be suitably used for various devices. Specifically, a refrigerator, a water heater, a heat pump type washing machine can be mentioned, for example.

  The present invention is not limited to the representative examples described in the first to fourth embodiments. Those skilled in the art can make various changes, modifications, and alterations without departing from the scope of the present invention.

(Details of function)
Details of each function described in the text will be described below. In these functions, the first to fourth embodiments satisfy all three functions and have a comprehensively high function as compared with the conventional example that cannot satisfy all functions simultaneously.

[Evaporation prevention function]
The evaporation prevention function is determined by the evaporation rate of the heat storage solution under a predetermined condition assuming the heat storage operation when an evaporation prevention layer or at least one sub-evaporation prevention layer is installed on the heat storage solution. . Specifically, an ethylene glycol 31% aqueous solution is filled as a heat storage solution in a heat storage container, and an evaporation preventing layer is laminated thereon by 20 mm and left in a 100 ° C. drier for 5 days to measure weight loss.

Weight loss with (X mg), and dividing by the cross-sectional area of the evaporation preventing layer (Scm ²⁾ and the test period (Y date), the evaporation rate [X / (S * Y) mg / (cm 2 · day)] As the calculated value is smaller, it means that the material has an excellent evaporation preventing effect. The evaporation rate is evaluated only by the evaporation preventing layer without filling the heat storage solution, and the evaporation rate value is calculated in consideration of the weight reduction rate of the material itself constituting the evaporation preventing layer.

[Leakage prevention function]
The leakage prevention function is determined based on the amount of the heat storage solution or the evaporation preventing layer leaking out of the container when the heat storage container is assumed to fall over during transportation. Specifically, the heat storage container is inclined 45 degrees at room temperature, and the amount of heat storage solution (ethylene glycol 31% aqueous solution) or the evaporation prevention layer leaks out of the container. The smaller the liquid amount, the higher the leakage prevention function. It means that.

[Pressure relaxation function]
The pressure relaxation function determines whether the upper evaporation prevention layer can release the internal pressure from the lower layer when the heat storage solution expands in the heat storage container due to the temperature rise during the heat storage operation and the liquid level rises To do. Specifically, when the temperature of the heat storage container is raised from room temperature to 100 ° C., it is measured how much the position of the evaporation preventing layer has moved upward from the initial stage, and only the heat storage solution is raised to 100 ° C. This means that the closer to the liquid level rising distance that is seen, the higher the function, and the lower the function or the lowering of the function when the evaporation prevention layer or the heat storage container is broken.

  The present invention can be used not only suitably for a heat storage device and an air conditioner, but also effectively used for a refrigerator, a water heater, a heat pump type washing machine, and the like.

DESCRIPTION OF SYMBOLS 11 Thermal storage solution layer 12 Air layer 13 Evaporation prevention layer 14 Subevaporation prevention layer 20A, 20B, 20C Thermal storage device 21,23 Thermal storage container 22,24 Thermal storage heat exchanger 25 Thermal conductive member 26 Compressor (heating source, heater )
214,234 Vent

Claims (13)

  A heat storage container having a vent hole communicating with the outside air is provided, and in the heat storage container, a heat storage solution layer and an evaporation prevention layer are formed in this order from the lower side, and the upper part of the evaporation prevention layer communicates with the outside air. The heat storage solution layer is composed of a sensible heat storage solution made of at least water, the air layer is formed by outside air flowing in from the vent holes, and the evaporation prevention layer is formed of the heat storage solution. A heat storage device comprising at least an organic compound having a specific gravity smaller than that of the heat storage solution and a melting point of not less than room temperature.   The heat storage device according to claim 1, wherein the organic compound is insoluble in the heat storage solution.   The heat storage device according to claim 1, wherein a melting point of the organic compound is lower than a boiling point of the heat storage solution.   In the heat storage container, at least one sub-evaporation prevention layer is further mixed with the evaporation prevention layer or formed as an independent layer below the evaporation prevention layer. The heat storage device according to claim 1, wherein the heat storage device is composed of a solvent composition comprising at least one water-insoluble solvent, and the melting point of the solvent composition is less than room temperature.   The heat storage device according to claim 4, wherein the specific gravity of the organic compound is smaller than the specific gravity of the solvent composition.   The heat storage device according to claim 4 or 5, wherein a melting point of the solvent composition is lower than a freezing point of the heat storage solution.   7. The solvent composition according to claim 4, wherein the solvent composition contains at least one of hydrocarbons having a carbon number in the range of 24 to 44 as the water-insoluble solvent. The heat storage device described in 1.   The heat storage device according to claim 1, wherein the heat storage solution is an aqueous solution containing a dihydric alcohol.   The heat source for heating the heat storage solution and the heat exchanger for heat storage for recovering the heat stored in the heat storage solution are further provided. The heat storage device described.   The heater is provided outside the heat storage solution layer, and the heat exchanger for heat storage is provided at a position immersed in the heat storage solution inside the heat storage container. The heat storage device according to 9.   The heat storage device according to claim 9 or 10, wherein the heat storage container is provided so as to surround the heating source.   The heat storage device according to any one of claims 9 to 11, wherein the heat storage container is in contact with the heating source via a heat conductive member.   An air conditioner comprising the heat storage device according to any one of claims 1 to 12.