JP2020020497A - Latent heat storage material composition - Google Patents

Abstract

To provide a latent heat storage material composition capable of reliably suppressing revelation of supercooling phenomenon and radiating stored latent heat with respect to a latent heat storage material essentially consisting of alum hydrate.SOLUTION: A latent heat storage material composition 1 is made by compounding an additive 20 for adjusting properties of a first latent heat storage material 11 to a latent heat storage material 10 (first latent heat storage material 11) which performs heat storage or heat radiation thereof as a main component. Therein, the first latent heat storage material 11 is ammonium alum 12 hydrate, the additive 20 is a super-cooling prevention agent 21 which facilitates induction of crystallization for the ammonium alum 12 hydrate in a molten liquid state as a first additive, and the super-cooling prevention agent 21 is calcium sulfate (CaSO).SELECTED DRAWING: Figure 1

Description

  TECHNICAL FIELD The present invention relates to a latent heat storage material composition in which a latent heat storage material that stores or releases heat by utilizing the inflow and outflow of latent heat due to a phase change is blended with an additive that suppresses the supercooling phenomenon of the latent heat storage material.

Latent heat storage material (PCM: Phase Change Material) has the property of storing or radiating heat by utilizing the ingress and egress of latent heat associated with a phase change. It stores waste heat that is originally discarded and needs the stored heat. By taking out according to the above, energy can be effectively used without waste. There are many substances serving as latent heat storage materials, and among them, for example, ammonium alum dodecahydrate (AlNH ₄ (SO ₄ ) ₂ .12H ₂ O) (hereinafter referred to as “ammonium alum”). Alum-based latent heat storage materials are widely used because of their excellent heat storage performance. Ammonium alum has a melting point of 93.5 ° C., is a white solid at room temperature, and becomes a colorless and transparent liquid at temperatures above the melting point.

  On the other hand, in the latent heat storage material, a supercooling phenomenon that does not crystallize even when cooled from a molten state to a temperature below a freezing point may occur. When the supercooling phenomenon occurs, the ammonium alum once melted does not solidify in the molten state, cannot radiate the latent heat, and is stored in the ammonium alum unless a supercooling prevention mechanism such as impacting the melt is provided. This makes it impossible to use the latent heat at different times. In order to prevent such a supercooling phenomenon, a supercooling inhibitor is generally compounded together with a latent heat storage material, as exemplified in Patent Document 1. The supercooling inhibitor is an additive that promotes crystallization of the latent heat storage material in a molten state.

Patent Document 1 discloses a heat storage material obtained by adding a mixture of calcium fluoride (CaF ₂ ) crystals and sulfur (S) crystals as a supercooling inhibitor to ammonium alum (melting point 94 to 95 ° C.) as a main component. is there. Patent Document 1 discloses a method in which a mixture of calcium fluoride crystals and sulfur crystals is housed in a basket and suspended in an ammonium alum solution, or a method in which calcium fluoride crystals and sulfur crystals are directly converted into ammonium alum. Means to be introduced into the solution. In Patent Literature 1, in any means, in canceling the supercooling phenomenon of the solution of ammonium alum, in the solution of ammonium alum, calcium fluoride crystals and sulfur crystals may be in contact with or close to each other, It is necessary for nucleation.

JP-B-57-349

  However, in Patent Document 1, since the supercooling inhibitor is a mixture of calcium fluoride crystals and sulfur crystals, the supercooling phenomenon is canceled if the adjustment for mixing the respective crystals is not performed in an appropriate state. There is a possibility that nuclei necessary for the formation may not be easily generated in the melt of ammonium alum. In addition, the supercooling inhibitor is a mixture of calcium fluoride crystals and sulfur crystals, and it is necessary to keep them in contact with or close to each other in order to perform nucleation. When the material is used, for example, for in-vehicle use in automobiles, for food-keeping, lunch-box, etc., during transportation, calcium fluoride crystals and sulfur crystals are largely separated from each other during transportation, and as a supercooling inhibitor There is a possibility that it will not function. Therefore, the heat storage material of Patent Literature 1 using a mixture of calcium fluoride crystals and sulfur crystals as a supercooling inhibitor is an inconvenient technology.

  The present invention has been made in order to solve the above problems, and the latent heat storage material containing alum hydrate as a main component, the occurrence of the supercooling phenomenon was more reliably suppressed and stored. An object of the present invention is to provide a latent heat storage material composition capable of releasing latent heat.

In order to achieve the above object, a latent heat storage material composition according to the present invention has the following configuration.
(1) A latent heat storage material composition comprising, as a main component, a latent heat storage material that performs heat storage or heat release by utilizing the entrance and exit of latent heat accompanying a phase change, and an additive that adjusts the physical properties of the latent heat storage material. In the above, the latent heat storage material is alum hydrate, and the additive is, as a first additive, a supercooling inhibitor that promotes crystallization of the alum hydrate in a molten state. Wherein the supercooling inhibitor is calcium sulfate (CaSO ₄ ).
(2) In the latent heat storage material composition described in (1), the blending ratio of the calcium sulfate in the total weight of the latent heat storage material composition is greater than 0 wt% and within a range of 10 wt% or less; It is characterized by.
(3) In the latent heat storage material composition according to (1) or (2), a second additive different from the first additive is blended as the additive, and The additive is a melting point adjusting agent that adjusts the melting point of the alum hydrate to an arbitrary temperature as needed.
(4) The latent heat storage material composition described in (3), wherein the melting point adjuster contains at least a substance belonging to sugar alcohols.
(5) In the latent heat storage material composition described in (4), the substance belonging to the sugar alcohols is erythritol (C ₄ H ₁₀ O ₄ ), xylitol (C ₅ H ₁₂ O ₅ ), or mannitol (C ₆ ). H ₁₄ O ₆ ).
(6) (1) through the latent heat storage material composition according to any one of (5), the alum hydrate, ammonium alum twelve dihydrate _{(AlNH 4 (SO 4) 2} · 12H 2 O) or potassium alum dodecahydrate (AlK (SO ₄ ) ₂ .12H ₂ O).

The operation and effect of the latent heat storage material composition of the present invention having the above configuration will be described.
(1) A latent heat storage material composition comprising, as a main component, a latent heat storage material that performs heat storage or heat release by utilizing the entrance and exit of latent heat accompanying a phase change, and an additive that adjusts the physical properties of the latent heat storage material. Wherein the latent heat storage material is an alum hydrate and the additive is a supercooling inhibitor that promotes crystallization of the alum hydrate in a molten state as a first additive The supercooling inhibitor is calcium sulfate (CaSO ₄ ). Due to this feature, even when the latent heat storage material composition of the present invention containing solid calcium sulfate (supercooling inhibitor) is heated from a solid state to a temperature higher than its melting point, the supercooling inhibitor is solid. As it is, since it is present in the melt of the latent heat storage material composition of the present invention, in the process of cooling this melt to a temperature lower than the melting point, on the surface of the solid supercooling inhibitor, the composition of alum hydrate is formed. Components can be adsorbed. As a result, crystal nuclei of alum hydrate (latent heat storage material) are generated as nuclei necessary for canceling the supercooling phenomenon of the alum hydrate. Therefore, the crystallization of the latent heat storage material is induced by the generation of crystal nuclei of alum hydrate based on the supercooling inhibitor, and the latent heat storage material composition of the present invention has a latent heat storage material in a cooling process from a molten state. The stored latent heat can be dissipated while suppressing the difference between the melting point and the freezing point of the material.

  Therefore, according to the latent heat storage material composition of the present invention, the latent heat storage material containing alum hydrate as a main component is more reliably suppressed from exhibiting the supercooling phenomenon, and the stored latent heat is radiated. It has an excellent effect that it can be done.

In the latent heat storage material composition described in (2), the blending ratio of calcium sulfate in the total weight of the latent heat storage material composition is greater than 0 wt% and is in the range of 10 wt% or less. . Due to this feature, in the process of cooling the latent heat storage material composition of the present invention from the molten state, the difference between the melting point and the freezing point of the latent heat storage material can be suppressed, and the stored latent heat can be radiated, and the volume can be radiated. The heat storage amount of the latent heat storage material composition of the present invention does not significantly decrease compared to the heat storage amount of the latent heat storage material alone with respect to the heat storage amount of the latent heat per unit.

In the latent heat storage material composition described in (3), a second additive different from the first additive is blended as an additive, and the second additive has a melting point of alum hydrate. Is a melting point adjuster that adjusts the temperature to an arbitrary temperature as needed. Due to this feature, the variation in the temperature at which latent heat is stored in the latent heat storage material composition of the present invention and the temperature at which the stored latent heat is released can be expanded by the melting point modifier.

In the latent heat storage material compositions described in (4) and (5), the melting point modifier is, for example, erythritol (C ₄ H ₁₀ O ₄ ), xylitol (C ₅ H ₁₂ O ₅ ), or mannitol (C ₆ H). ₁₄ O ₆ ), which contains at least a substance belonging to sugar alcohols, such as a substance containing at least one of them. With this feature, the melting temperature of the latent heat storage material composition according to the present invention can be adjusted, and the viscosity of the latent heat storage material composition according to the present invention increases, resulting from the difference in density between the latent heat storage material and the supercooling inhibitor. Separation of the constituent components of the latent heat storage material composition according to the present invention, such as separation of the latent heat storage material from the supercooling inhibitor and separation of the constituent components of the latent heat storage material itself, can be prevented. Therefore, the latent heat storage material composition of the present invention can be a chemically stable heat storage material because non-uniformity between the components of the latent heat storage material composition according to the present invention does not occur. Moreover, by adding the melting point modifier to the latent heat storage material, the melting point of the latent heat storage material can be significantly adjusted, and the melting point modifier itself has heat storage performance. The latent heat storage material composition of the present invention has physical properties of a large amount of heat storage, for example, about 350 kJ / L.

In the latent heat storage material composition described in (6), the alum hydrate is ammonium alum dodecahydrate (AlNH ₄ (SO ₄ ) ₂ .12H ₂ O) or potassium alum dodecahydrate ( AlK (SO ₄ ) ₂ .12H ₂ O). Due to this feature, ammonium alum decahydrate and potassium alum decahydrate are widely distributed in the market, easily available, and inexpensive.

It is a figure which shows typically the component of the latent-heat-storage material composition which concerns on Example 1 of embodiment. It is a figure which shows typically the component of the latent-heat-storage material composition which concerns on Example 2 of embodiment. It is a figure which shows typically the component of the latent-heat-storage material composition which concerns on Example 3 of embodiment. 4 is a graph showing a heat release test result of the latent heat storage material compositions according to Examples 1 and 2. 9 is a graph showing a heat release test result of the latent heat storage material composition according to Example 3. It is a graph which shows the heat dissipation test result of the latent heat storage material concerning a comparative example.

(Embodiment)
Hereinafter, embodiments (Examples 1 to 3) of the latent heat storage material composition according to the present invention will be described in detail with reference to the drawings. The purpose of the latent heat storage material composition is to temporarily store the heat provided by the heat supply source in the latent heat storage material, and then use the latent heat stored in the latent heat storage material at the heat demand destination with a time difference. Used in Such a latent heat storage material composition is filled in a liquid-tight and air-tight manner into a filling container (not shown) accommodated in a space of a predetermined accommodating means in a leak-free manner. Thus, the stored heat can be taken out as needed by utilizing the incoming and outgoing of the latent heat, and the cycle of the heat storage and the heat radiation is used plural times.

The latent heat storage material composition contains, as a main component, a latent heat storage material that performs heat storage or heat release by utilizing the entrance and exit of latent heat due to a phase change, and one or more additives that adjust the physical properties of the latent heat storage material. Do it. The latent heat storage material is alum hydrate. The additive is, as a first additive, a supercooling inhibitor that promotes the induction of crystallization of the alum hydrate in a molten state. The supercooling inhibitor is calcium sulfate (CaSO ₄ ). is there. Calcium sulfate has a molecular weight of [g / mol] 136.14, a melting point of 1460 ° C., and at a temperature lower than the melting point, it is a colorless solid formed of crystals or powder and has a property of being slightly soluble in water. The blending ratio of calcium sulfate in the total weight of the latent heat storage material composition is greater than 0 wt% and within a range of 10 wt% or less.

  The configuration of the latent heat storage material composition will be specifically described with reference to Examples 1 to 3.

(Example 1)
FIG. 1 is a diagram schematically illustrating components of a latent heat storage material composition according to Example 1 of the embodiment. As shown in FIG. 1, the latent heat storage material composition 1 according to Example 1 is a heat storage material in which one kind of the latent heat storage material 10 and one kind of the additive 20 are blended. In the first embodiment, the latent heat storage material 10 may be referred to as ammonium alum dodecahydrate (ammonium aluminum sulfate · 12 water: AlNH ₄ (SO ₄ ) ₂ · 12H ₂ O) (hereinafter, also referred to as “ammonium alum”). .) (First latent heat storage material 11). Ammonium alum has a hydration number of 12, a molecular weight of [g / mol] 453.34, a melting point of 93.5 ° C, is solid at room temperature, and has water-soluble properties. Therefore, even if ammonium alum alone is heated at a temperature lower than the melting point, it hardly melts and cannot store latent heat. The additive 20 is the supercooling inhibitor 21 which is the above-mentioned calcium sulfate.

(Example 2)
Next, the configuration of the latent heat storage material composition according to Example 2 will be described with reference to FIG. FIG. 2 is a diagram schematically illustrating components of a latent heat storage material composition according to Example 2 of the embodiment. As shown in FIG. 2, the latent heat storage material composition 2 according to Example 2 is a heat storage material in which two types of the latent heat storage material 10 and one type of the additive 20 are blended. The additive 20 is the supercooling inhibitor 21 which is the above-mentioned calcium sulfate.

In the second embodiment, the latent heat storage material 10 is a heat storage material in which a first latent heat storage material 11 and a second latent heat storage material 12 are mixed. The first latent heat storage material 11 is ammonium alum decahydrate (AlNH ₄ (SO ₄ ) ₂ .12H ₂ O), and the second latent heat storage material 12 is potassium alum decahydrate (potassium aluminum sulfate). 12 water: AlK (SO ₄ ) ₂ .12H ₂ O) (hereinafter sometimes referred to as “calilum”). Kali alum has a hydration number of 12, a molecular weight [g / mol] of 474.388, a melting point of 92.5 ° C, is solid at room temperature, and has water-soluble properties. Therefore, even if the alum is heated alone at a temperature lower than the melting point, it is hardly melted and the latent heat cannot be stored.

Incidentally, constituents of the latent heat storage material 10, in addition to ammonium alum and potassium alum, for example, chrome alum _{(CrK (SO 4) 2 ·} 12H 2 O), iron alum _{(FeNH 4 (SO 4) 2} · 12H 2 O), etc., to a monovalent sulfate cations ^M _I 2 (SO _4), a trivalent sulfate cation ^M _III 2 _{(SO 4) 3} and double sulfate "alum", water It may be “alum hydrate” having a hydrate. Further, the trivalent metal ions contained in the “alum” may be, for example, metal ions such as cobalt ions and manganese ions in addition to aluminum ions, chromium ions, and iron ions. Further, the latent heat storage material 10 may be a mixture containing at least two or more of such substances belonging to “alum hydrate”, or a heat storage material mainly containing a mixed crystal.

(Example 3)
FIG. 3 is a diagram schematically illustrating components of a latent heat storage material composition according to Example 3 of the embodiment. As shown in FIG. 3, the latent heat storage material composition 3 according to Example 3 is a heat storage material in which one type of the latent heat storage material 10 and two types of the additives 20 are blended. In the third embodiment, the latent heat storage material 10 is a single type (first latent heat storage material 11) of ammonium alum dodecahydrate (AlNH ₄ (SO ₄ ) ₂ .12H ₂ O).

  The additive 20 will be described. Of the two additives 20, the first additive, the supercooling inhibitor 21, is the above-described calcium sulfate. In addition, the latent heat storage material composition 3 contains a second additive as an additive 20 separately from the supercooling inhibitor 21. The second additive requires the melting point of ammonium alum. Is a melting point adjuster 22 that adjusts to an arbitrary temperature according to the temperature.

In the third embodiment, the melting point modifier 22 contains at least a substance belonging to sugar alcohols mainly used in food additives, and dissolves with alum hydrate (latent heat storage material) to reduce the heat of dissolution. It is a substance having physical properties to be generated. Sugar alcohols are a type of sugar generated by reducing the carbonyl group of aldose or ketose, and dissolve in water. The melting point regulator 22 is at least one of erythritol (C ₄ H ₁₀ O ₄ ), xylitol (C ₅ H ₁₂ O ₅ ), and mannitol (C ₆ H ₁₄ O ₆ ) belonging to such sugar alcohols. Including one. Specifically, in the third embodiment, the melting point modifier 22 is mannitol. Mannitol has a hydration number of 12, a molecular weight of [g / mol] 182.17, a melting point of 166 to 168 ° C, and water-soluble properties.

  Since mannitol can adjust the melting temperature of the latent heat storage material composition 3 and has a viscosity increasing the viscosity of the latent heat storage material composition 3, the latent heat storage material 10 and the supercooling inhibitor 21 Can be prevented from separating from the latent heat storage material 10 and the supercooling preventive agent 21 due to the density difference between the components and the components of the latent heat storage material 10 that is the main component. Therefore, since the nonuniformity between the components of the latent heat storage material composition 3 does not occur, the latent heat storage material composition 3 can be a chemically stable heat storage material. In addition, the melting point modifier 22 is added to the latent heat storage material 10, so that the melting point of the latent heat storage material 10 can be greatly adjusted. In addition, the melting point regulator 22 itself has heat storage performance. Even so, the latent heat storage material composition 3 can store a large amount of latent heat having a heat storage amount of about 350 kJ / L.

  The mixing ratio of mannitol to the total weight of the latent heat storage material composition 3 is within a range of 20 wt% or less. When mannitol is contained in the latent heat storage material composition 3 within such a range, the melting point of the latent heat storage material composition 3 can be adjusted to about 90 ° C. by mannitol without any adverse effect. If the blending amount of mannitol exceeds this range and is added to the latent heat storage material composition 3, the melting point of mannitol mixed with the latent heat storage material composition 3 becomes higher than the melting point of mannitol alone, And the phase change between alum hydrate and mannitol does not occur at the same time, and when the upper limit of the heating operation is set to 90 to 100 ° C., the heat storage amount of the latent heat storage material composition 3 is approximately equal to the heat storage amount. It will drop below 350 kJ / L.

  Here, the definition of the “substance having physical properties that generate negative heat of dissolution” will be described. As described above, the latent heat storage material composition 3 is composed of ammonium alum (latent heat storage material 10) as a main component, and a supercooling inhibitor 21 and a melting point regulator 22. When the melting point adjusting agent 22 is dissolved in the latent heat storage material 10, the melting point adjusting agent 22 that absorbs heat from the outside and causes an endothermic reaction is referred to as “negative” in the latent heat storage material composition 3 according to the present embodiment. Substance having the property of generating heat of dissolution of

Examples of the “substance having physical properties that generate negative heat of solution” include, in addition to erythritol, xylitol, and mannitol exemplified above, for example, sorbitol (C ₆ H ₁₄ O ₆ ), lactitol (C ₁₂ H ₂₄ O ₁₁ ) And the like, “substances belonging to sugar alcohols”. In addition to “substances belonging to sugar alcohols”, calcium chloride hexahydrate (CaCl ₂ .6H ₂ O), magnesium chloride hexahydrate (MgCl ₂ .6H ₂ O), potassium chloride (KCl), There is a "substance belonging to chloride" such as sodium chloride (NaCl). In addition, there are “substances belonging to sulfates” such as ammonium sulfate ((NH ₄ ) ₂ SO ₄ ). In addition, in addition to the case of including at least one or more of the substances corresponding to the above-mentioned “substances belonging to sugar alcohols”, the case of including at least one or more of the substances corresponding to the above-described “substances belonging to chloride”, This also applies to a case in which at least one or more of the above-mentioned “substances belonging to sulfates” are contained.

  In addition, there is a mixture of any of the above-mentioned substances belonging to “sugar alcohols” and any of the above-mentioned substances belonging to “chloride”. There is also a mixture of any of the above-mentioned substances belonging to “sugar alcohols” and any of the above-mentioned substances belonging to “sulfate”. Furthermore, any of the above-mentioned substances belonging to the "sugar alcohols", any one of the above-mentioned "substances belonging to the chloride", and the above-mentioned "substances belonging to the sulfate" (Including a mixed crystal of chloride and sulfate).

  In addition, care must be taken in handling, and in this embodiment, the use as a latent heat storage material composition is not preferred.For example, ammonium nitrate and potassium chlorate also exhibit an endothermic reaction when dissolved in water, The substance falls under "substances having physical properties that generate negative heat of solution".

<Implementation of verification experiment>
Next, experiments 1 to 4 were performed for the purpose of verifying the effect of the supercooling preventive agent 21 in releasing the supercooling phenomenon in the latent heat storage material 10. Experiment 1 is an experiment performed on Sample 1 in which 100 g of the latent heat storage material composition 1 according to Example 1 described above was sealed in an aluminum laminate bag. Experiment 2 is an experiment performed on Sample 2 in which 100 g of the latent heat storage material composition 2 according to Example 2 described above was sealed in an aluminum laminate bag. Experiment 3 is an experiment performed on Sample 3 in which 100 g of the latent heat storage material composition 3 according to Example 3 was sealed in an aluminum laminate bag. Experiment 4 is an experiment performed as a comparative example of Examples 1 to 3, in which 100 g of only the latent heat storage material 10 (first latent heat storage material 11) containing no supercooling inhibitor 21 was sealed in an aluminum laminate bag. This is the experiment performed in

<Experiment method>
In Experiments 1 to 4, in each experiment, the latent heat storage material compositions 1 to 3 (or the latent heat storage material 10) in the sample were first heated in a thermostat to 95 ° C. or higher with a heater in the thermostat. After confirming in advance that the latent heat storage material composition 1 and the like had completely melted, the operation of the heater was turned off. Then, the temperature of the latent heat storage material composition 1 and the like in the molten state is air-cooled while measuring the state temperature of the latent heat storage material composition 1 and the like for 8 hours or more in the bath with the door of the thermostatic bath closed. To complete solid state. In all the experiments, the operation of the heater was turned off, and at the same time, the measurement of the state temperature of the latent heat storage material composition 1 and the like was started, and the temperature was continuously maintained until the temperature of the latent heat storage material composition 1 and the like hardly changed. A measurement was made. At the same time, the ambient temperature in the thermostat was also measured.

<Common conditions of Experiments 1 to 3>
· Supercooling inhibitor 21; calcium sulfate (CaSO ₄₎
<Conditions of Experiment 4>
・ Supercooling inhibitor 21; not blended

<Conditions of Experiment 1>
-Sample 1: using latent heat storage material composition 1 (a heat storage material in which one kind of latent heat storage material 10 and one kind of additive 20 are blended), each of which is prepared in the following first to third levels.-Latent heat storage material 10; ammonium alum dodecahydrate (AlNH ₄ (SO ₄ ) ₂ .12H ₂ O) (first latent heat storage material 11)
-Additive 20; only supercooling preventive agent 21-Compounding ratio (wt%) of first latent heat storage material 11 and supercooling preventive agent 21
99: 1 (first level), 95: 5 (second level), 90:10 (third level)
・ Repeated number of experiments: 1 each for 1st to 3rd level

<Conditions of Experiment 2>
Sample 2: latent heat storage material composition 2 (a heat storage material in which two types of latent heat storage materials 10 and one type of additive 20 are blended), each of which is prepared in the following first to third levels. Latent heat storage material 10 ; ammonium alum twelve dihydrate _{(AlNH 4 (SO 4) 2} · 12H 2 O) ( first phase change material 11) and potassium alum twelve dihydrate (potassium aluminum sulfate, 12 water: AlK _(SO 4) Mixture with ( ₂ · 12H ₂ O) (second latent heat storage material 12) / additive 20; only supercooling inhibitor 21 / first superheat prevention material 11, second latent heat storage material 12, and supercooling prevention agent 21 Mixing ratio (wt%)
49.5: 49.5: 1.0 (first level), 47.5: 47.5: 5.0 (second level), 45:45:10 (third level)
・ Repeated number of experiments: 1 each for 1st to 3rd level

<Conditions of Experiment 3>
Sample 3; latent heat storage material composition 3 (a heat storage material in which one kind of latent heat storage material 10 and two kinds of additives 20 are blended), each of which is prepared in the following first to third levels. Ammonium alum dodecahydrate (AlNH ₄ (SO ₄ ) ₂ .12H ₂ O) (first latent heat storage material 11)
Additive 20: mannitol (C ₆ H ₁₄ O ₆ ) (melting point regulator 22) and calcium sulfate (CaSO ₄ ) (supercooling inhibitor 21)
-Compounding ratio (wt%) of the first latent heat storage material 11, the melting point regulator 22, and the supercooling inhibitor 21
91.08: 7.92: 1.00 (first level), 87.4: 7.6: 5.0 (second level), 82.8: 7.2: 10.0 (third level)
・ Number of repetitions The first level and the second level are each once, and the third level is twice.

<Conditions of Experiment 4>
Sample 4; latent heat storage material 10; first level only; latent heat storage material 10; ammonium alum dodecahydrate (AlNH ₄ (SO ₄ ) ₂ .12H ₂ O) (first latent heat storage material 11)
・ Additive 20; not blended ・ Blending ratio (wt%) of first latent heat storage material 11 and supercooling inhibitor 21
100: 0 (first level)

FIG. 3 is a diagram schematically illustrating components of a latent heat storage material composition according to Example 3. FIG. 4 is a graph showing the results of a heat release test of the latent heat storage material compositions according to Examples 1 and 2. FIG. 5 is a graph showing a heat release test result of the latent heat storage material composition according to Example 3. FIG. 6 is a graph showing a heat release test result of the latent heat storage material according to the comparative example. In the annotation columns described in FIGS. 4 to 6, the notation consisting of English characters and symbols indicates the contents of the components of the latent heat storage material composition and the contents of the components of the latent heat storage material, The details are as follows.
<Fig. 4>
"Al * Alum"; ammonium alum (first latent heat storage material 11)
-"K * Alum"; Kali alum (second latent heat storage material 12)
"Ca": calcium sulfate (supercooling inhibitor 21)
<Fig. 5>
"Al * Alum"; ammonium alum (first latent heat storage material 11)
· "Ma"; mannitol _{(C 6 H 14 O 6)} ( mp modifier 22)
"Ca": calcium sulfate (supercooling inhibitor 21)
<Fig. 6>
"Al * Alum"; ammonium alum (first latent heat storage material 11)

<Experimental results>
In the results of Experiments 1 and 2, as shown in FIG. 4, after the start of the temperature measurement, the ambient temperature in the thermostat continued to decrease with the passage of time. On the other hand, the temperature of the latent heat storage material composition 1 of the sample 1 according to the example 1 and the temperature of the sample according to the example 2 until the time t1a when the ambient temperature in the constant temperature bath became around 76 ° C. (= T1a). The temperature of the latent heat storage material composition 2 of Example 2 continued to decrease over time, regardless of the level of the sample. However, after the time t1a, the temperature of the latent heat storage material composition 1 of the sample 1 and the temperature of the latent heat storage material composition 2 of the sample 2 rise once, regardless of the level of the sample, and then gradually change. And began to fall again at a slow cooling rate. Then, when reaching the time t1b, the temperature of the latent heat storage material composition 1 of the sample 1 and the temperature of the latent heat storage material composition 2 of the sample 2 are around 34 ° C. (= T1b) in the constant temperature bath. I almost came to match. Between the time t1a and the time t1b, the latent heat storage material composition 1 of the sample 1 according to the example 1 and the latent heat storage material composition 2 of the sample 2 according to the example 2 The behavior of the stored latent heat radiation was confirmed.

  In the result of Experiment 3, as shown in FIG. 5, after the start of the temperature measurement, the ambient temperature in the thermostat continued to decrease with the passage of time. On the other hand, the temperature of the latent heat storage material composition 3 of the sample 3 according to the example 3 was not changed until the time t2a when the ambient temperature in the thermostat became around 67 ° C. (= T2a), regardless of the sample level. , Continued to fall over time. However, after time t2a, the temperature of the latent heat storage material composition 3 of the sample 3 once rises regardless of the level of the sample, and then starts to decrease again at a slow temperature decreasing rate while performing a gradual temperature change. Was. When reaching the time t2b, the temperature of the latent heat storage material composition 3 of the sample 3 became almost the same when the ambient temperature in the thermostat was around 26 ° C. (= T2b). From time t2a to time t2b, in the latent heat storage material composition 3 of the sample 3 according to Example 3, the behavior of the latent heat release stored in the latent heat storage material composition 3 was confirmed.

  In the result of Experiment 4, as shown in FIG. 6, after the temperature measurement was started, the ambient temperature in the thermostat continued to decrease with the passage of time, but the latent heat of Sample 4 according to the comparative example was the same as the ambient temperature. The temperature of the heat storage material 10 also continued to decrease over time. That is, as shown in the results of Experiments 1 to 3, in the latent heat storage material compositions 1 to 3 under the cooling process, the temperature of the state once increased, and after a gradual temperature change, at a slow cooling rate. The phenomenon of falling again was not observed in Experiment 4. In the latent heat storage material 10 of the sample 4 according to the comparative example, the behavior of the latent heat release due to the phase change from the melt state to the solid state was confirmed except that the temperature drop became slightly slow after 20,000 seconds. Was not confirmed.

<Discussion>
The latent heat storage material, by heating above its melting point, during the phase change from the solid state to the melt state, stores the latent heat and performs heat storage, and in the process of cooling at a temperature below the melting point, from the melt state to the solid state During the phase change, the stored latent heat is radiated to the outside. In the comparative example, the latent heat storage material 10 of the sample 4 is only a single kind of ammonium alum (the first latent heat storage material 11). Therefore, in Sample 4, if the temperature of the melt of the first latent heat storage material 11 is cooled to a temperature lower than the melting point of 93.5 ° C., the ammonium alum which was originally in a melt state of 95 ° C. or more is theoretically obtained. Originally, the stored latent heat is radiated to the outside by the phase change to the solid state, and the state temperature of the first latent heat storage material 11 should temporarily rise with this heat release.

  However, from the result of Experiment 4, since the behavior of the latent heat radiation from the first latent heat storage material 11 does not exist, even if the temperature of the first latent heat storage material 11 becomes lower than the melting point of 93.5 ° C., the solid state is obtained. It can be seen that a supercooling phenomenon that does not cause a phase change occurs. In sample 4 of the comparative example, the nucleus necessary for canceling such a supercooling phenomenon was not present in the melt of ammonium alum (first latent heat storage material 11), and sample 4 also had a supercooling inhibitor. It is considered that the supercooling phenomenon has occurred in the first latent heat storage material 11 because no is contained.

  On the other hand, in Samples 1 to 3 according to Examples 1 to 3, while cooling the latent heat storage material compositions 1 to 3 by air cooling, the state temperature of the latent heat storage material compositions 1 to 3 is: When the temperature falls below the melting point, but reaches a temperature relatively close to the melting point, the temperature temporarily rises, and the temperature in the largest case is close to 20 ° C. with respect to the ambient temperature which had tended to be almost the same. By the difference, the high temperature state can be maintained. Such behavior is caused by the latent heat storage material 10 avoiding the occurrence of the supercooling phenomenon, and the latent heat storage material compositions 1 to 3 themselves are heated by the latent heat radiation accompanying the phase change from the melt state to the solid state. It is thought that it was done.

  In other words, in the latent heat storage material compositions 1 to 3, in addition to the latent heat storage material 10, a supercooling preventive agent 21 made of calcium sulfate is compounded. The nucleus necessary to cancel the supercooling phenomenon exists in the melt of the latent heat storage material 10 such as ammonium alum. Therefore, it is considered that the latent heat storage material 10 such as ammonium alum eliminates the occurrence of the supercooling phenomenon.

Next, the operation and effect of the latent heat storage material compositions 1 to 3 of the present embodiment will be described. The latent heat storage material compositions 1 to 3 of the present embodiment are mainly composed of the latent heat storage material 10 that performs heat storage or heat release by utilizing the entrance and exit of the latent heat accompanying the phase change, and adjust the physical properties of the latent heat storage material 10. Latent heat storage material in the latent heat storage material composition containing the additive 20 to be added, the additive 20 is an alum hydrate in a molten state as a first additive. On the other hand, the supercooling inhibitor 21 that promotes the induction of crystallization is characterized in that the supercooling inhibitor 21 is calcium sulfate (CaSO ₄ ).

  Due to this feature, even when the latent heat storage material compositions 1 to 3 containing solid calcium sulfate (supercooling inhibitor 21) are heated from the solid state to a temperature higher than the melting point, the supercooling inhibitor 21 is solid. In the process of cooling the melt to a temperature equal to or lower than the melting point, the alum hydration is applied to the surface of the solid supercooling preventive agent 21 because the melt exists in the melt of the latent heat storage material compositions 1 to 3 as it is. The constituents of the product can be adsorbed. As a result, crystal nuclei of alum hydrate (latent heat storage material 10) are generated as nuclei necessary for canceling the supercooling phenomenon of the alum hydrate. Therefore, the crystallization of the latent heat storage material 10 is induced by the generation of the crystal nucleus of the alum hydrate based on the supercooling inhibitor 21, and the latent heat storage material compositions 1 to 3 are cooled in the process of cooling from the melt state. The stored latent heat can be radiated while suppressing the difference between the melting point and the freezing point of the latent heat storage material 10.

  Here, the reason why calcium sulfate (supercooling inhibitor 21) can be adsorbed to the constituents of alum hydrate will be described. Since alum hydrate contains 12 hydration waters per molecule, the melt of alum hydrate melted by heating is an aqueous solution. On the other hand, calcium sulfate is a substance having extremely low solubility in water, and has a melting point of 1460 ° C. In such a latent heat storage material composition in which calcium sulfate is added to alum hydrate, even if the alum hydrate is heated and melted, the calcium sulfate does not melt itself, and the alum hydrate is dissolved. Since it hardly dissolves in hydration water, it remains as a solid in the alum hydrate melt. Therefore, since the supercooling inhibitor 21 is solid and exists in the melt of the latent heat storage material compositions 1 to 3, the components of the alum hydrate are adsorbed on the surface of the solid supercooling inhibitor 21. It is thought that we can do it.

  Therefore, according to the latent heat storage material compositions 1 to 3 of the present embodiment, the latent heat storage material 10 containing alum hydrate as a main component more reliably suppresses the occurrence of a supercooling phenomenon and stores heat. An excellent effect that the latent heat can be dissipated.

  In addition, in the latent heat storage material compositions 1 to 3 of the present embodiment, the mixing ratio of calcium sulfate in the total weight of the latent heat storage material compositions 1 to 3 is greater than 0 wt% and is in the range of 10 wt% or less. It is characterized by the following. Due to this feature, in the process of cooling the latent heat storage material compositions 1 to 3 from the molten state, the difference between the melting point and the freezing point of the latent heat storage material 10 is suppressed, and the amount of latent heat storage per volume is determined by the latent heat storage material. Compared to the amount of heat stored by itself, the amount of latent heat can be sufficiently released for practical use without being significantly reduced. As a reason, calcium sulfate itself does not have a heat storage performance in the temperature band of the latent heat storage material compositions 1 to 3 to be used (for example, a band of about 100 ° C. or less). Therefore, when the supercooling preventing agent 21 is blended beyond such a blending ratio, the amount of latent heat storage material compositions 1 to 3 in terms of the amount of latent heat storage per unit volume of the latent heat storage material 10 alone However, when the blending ratio of calcium sulfate is within the above range, the heat storage amounts of the latent heat storage material compositions 1 to 3 do not significantly decrease.

  Further, in the latent heat storage material compositions 1 to 3 of the present embodiment, a second additive different from the first additive (the supercooling preventing agent 21) is blended as the additive 20. Is characterized in that it is a melting point regulator 22 that adjusts the melting point of alum hydrate (latent heat storage material 10) to an arbitrary temperature as needed. With this feature, the variation in the temperature at which latent heat is stored in the latent heat storage material compositions 1 to 3 and the temperature at which the stored latent heat is released can be expanded by the melting point regulator 22. Therefore, the latent heat radiation of the latent heat storage material compositions 1 to 3 is directed, for example, to a hot water supply facility that requires heat in a temperature range of 80 to 90 ° C., or a heat supply facility such as an air conditioning facility that performs cooling and heating. , Will be able to supply. In addition, the latent heat radiation of the latent heat storage material compositions 1 to 3 is applied to a heat storage system that uses heat energy of exhaust heat generated in a vehicle at a utilization destination in the vehicle as an application to an automobile technology, For transporting biological materials such as cells and cells, and medical articles such as pharmaceuticals at a constant temperature, and for keeping food in the daily diet until meals, lunches, lunch boxes, dishes, and ingredients. It can be used for various applications in various fields.

In the latent heat storage material composition 3 of the present embodiment, the melting point modifier 22 is, for example, erythritol (C ₄ H ₁₀ O ₄ ), xylitol (C ₅ H ₁₂ O ₅ ), or mannitol (C ₆ H ₁₄ O). ₆ ) It is characterized in that it contains at least a substance belonging to sugar alcohols, such as a substance containing at least one of them. With this feature, the melting temperature of the latent heat storage material composition 3 can be adjusted, the viscosity of the latent heat storage material composition 3 increases, and the latent heat storage material caused by the density difference between the latent heat storage material 10 and the supercooling inhibitor 21. It is possible to prevent the components of the latent heat storage material composition 3 from being separated from each other, such as the separation between the supercooling inhibitor 10 and the components of the latent heat storage material 10 itself. Therefore, since the nonuniformity between the components of the latent heat storage material composition 3 does not occur, the latent heat storage material composition 3 can be a chemically stable heat storage material. In addition, the melting point modifier 22 is added to the latent heat storage material 10, so that the melting point of the latent heat storage material 10 can be greatly adjusted. In addition, the melting point regulator 22 itself has heat storage performance. Even so, the latent heat storage material composition 3 has physical properties having a large heat storage amount of, for example, about 350 kJ / L.

In the latent heat storage material compositions 1 to 3 of the present embodiment, the alum hydrate is ammonium alum dodecahydrate (AlNH ₄ (SO ₄ ) ₂ .12H ₂ O) or potassium alum dodecahydrate. Characterized by containing at least one of a hydrate (AlK (SO ₄ ) ₂ .12H ₂ O). Due to this feature, ammonium alum decahydrate and potassium alum decahydrate are widely distributed in the market, easily available, and inexpensive.

  In the above, the present invention has been described with reference to Examples 1 to 3 of the embodiment. However, the present invention is not limited to Examples 1 to 3 of the above embodiment, and does not depart from the gist of the present invention. It can be changed as appropriate and applied.

  For example, in the embodiment, regarding the ratio of the constituent components of the latent heat storage material compositions 1 to 3, in Experiment 1, the mixing ratio (wt%) of the first latent heat storage material 11 and the supercooling inhibitor 21 is 99: 1. (1st level), 95: 5 (2nd level), and 90:10 (3rd level) were exemplified. In Experiment 2, the blending ratio (wt%) of the first latent heat storage material 11, the second latent heat storage material 12, and the supercooling inhibitor 21 was set to 49.5: 49.5: 1.0 (first level). ), 47.5: 47.5: 5.0 (second level), and 45:45:10 (third level). In Experiment 3, the mixing ratio (wt%) of the first latent heat storage material 11, the melting point regulator 22, and the supercooling inhibitor 21 was 91.08: 7.92: 1.00 (first level), The latent heat storage material composition 3 having 87.4: 7.6: 5.0 (second level) and 82.8: 7.2: 10.0 (third level) is exemplified.

  However, in the latent heat storage material composition, the mixing ratio of the latent heat storage material and the additive is merely an example, and is not limited to the embodiment, and there is no problem in using the latent heat storage material composition. For example, the mixing ratio of the latent heat storage material and the additive to the latent heat storage material composition can be appropriately changed.

  In the embodiment, the latent heat storage material 10 is composed of ammonium alum dodecahydrate (first latent heat storage material 11) alone, or ammonium alum dodecahydrate (first latent heat storage material 11) and potassium alum 12 Although the mixture with the hydrate (the second latent heat storage material 12) was used, the latent heat storage material is not limited to this embodiment, and may be any alum hydrate.

1, 2 latent heat storage material composition 10 latent heat storage material 11 1st latent heat storage material (latent heat storage material)
12 Second latent heat storage material (latent heat storage material)
Reference Signs 20 additives 21 supercooling inhibitor (additive, first additive)
22 Melting point modifier (second additive)

Claims (6)

A latent heat storage material composition comprising a latent heat storage material that performs heat storage or heat radiation by utilizing the inflow and outflow of latent heat due to a phase change, and an additive that adjusts the physical properties of the latent heat storage material.
The latent heat storage material is alum hydrate, and the additive is, as a first additive, a supercooling inhibitor that promotes crystallization of the alum hydrate in a molten state. thing,
The supercooling inhibitor is calcium sulfate (CaSO ₄ );
A latent heat storage material composition comprising: The latent heat storage material composition according to claim 1,
A mixing ratio of the calcium sulfate to the total weight of the latent heat storage material composition is greater than 0 wt% and within a range of 10 wt% or less;
A latent heat storage material composition comprising: The latent heat storage material composition according to claim 1 or 2,
As the additive, a second additive different from the first additive is blended, and the second additive may adjust the melting point of the alum hydrate to an arbitrary temperature if necessary. Melting point adjusting agent to be adjusted to
A latent heat storage material composition comprising: The latent heat storage material composition according to claim 3,
The melting point adjuster contains at least a substance belonging to sugar alcohols,
A latent heat storage material composition comprising: The latent heat storage material composition according to claim 4,
The substance belonging to the sugar alcohols includes at least one of erythritol (C ₄ H ₁₀ O ₄ ), xylitol (C ₅ H ₁₂ O ₅ ), and mannitol (C ₆ H ₁₄ O ₆ ). thing,
A latent heat storage material composition comprising: The latent heat storage material composition according to any one of claims 1 to 5,
The alum hydrate is ammonium alum dodecahydrate (AlNH ₄ (SO ₄ ) ₂ .12H ₂ O) or potassium alum dodecahydrate (AlK (SO ₄ ) ₂ .12H ₂ O). Including at least one of them,
A latent heat storage material composition comprising:

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