Patent Application
20230020444
The present invention relates to a heat storage material composition.
Latent heat storage material compositions that utilize the latent heat generated or absorbed during the phase change from liquid to solid or from solid to liquid have been known. Latent heat storage material compositions are used, for example, in heat storage systems for heating and cooling a structure. Hereinafter, the latent heat storage material composition is simply referred to as a “heat storage material composition”.
It is desired that heat storage material compositions have a stable and sufficient heat storage effect stably in an intended temperature range. Thus, for example, when a heat storage material composition is used in a heat storage system for heating and cooling a structure, it is desired that the heat storage material composition has a large amount of heat storage and the melting point and solidification point of the heat storage material composition match or approximate conditions of use in the heating and cooling of a structure. Here, the melting point means a temperature at which the heat storage material composition melts in a temperature increasing process, and the solidification point means a temperature at which the heat storage material composition solidifies in a cooling process.
It is desirable that the melting point of the heat storage material composition used in the heat storage system for heating and cooling a structure be 27° C. or lower.
It is preferable that the heat storage material composition used in the heat storage system for heating and cooling a structure have a narrow melting temperature range and a high latent heat of melting in this melting temperature range. Here, the melting temperature range means a temperature range from the start to the end of melting, specifically, a difference ΔT(=T2−T1) between “a temperature T1 at which melting of the heat storage material composition begins and a liquid phase begins to occur” and “a temperature T2 at which melting of the heat storage material composition is completed and all of the heat storage material composition becomes liquid phase” in the temperature increasing process. In other words, it is desirable that the heat storage material composition used in a heat storage system for heating and cooling a structure have a high latent heat of melting in a narrow melting temperature range.
As a conventional heat storage material composition, Patent Literature 1 (Japanese Unexamined Patent Application Publication No. S59-109578) discloses a heat storage material composition made from calcium chloride hexahydrate with ammonium salt such as ammonium chloride, ammonium bromide, or ammonium nitrate.
However, the heat storage material composition of Patent Literature 1 is not suitable for use in a heat storage system for heating and cooling a structure because its melting point exceeds 27° C. The heat storage material composition of Patent Literature 1 has a wide melting temperature range.
The present invention has been made in consideration of issues such as that described above. An object of the present invention is to provide a heat storage material composition that has a melting point of 27° C. or lower and a high latent heat of melting in a narrow melting temperature range.
A heat storage material composition according to an aspect of the present invention includes a main agent mixture composed of calcium chloride hexahydrate. ammonium chloride, and water, wherein when the content of calcium chloride hexahydrate is defined as CA mass %, the content of ammonium chloride is defined as NH mass %, and the content of water is defined as W mass % in 100 mass % of the main agent mixture, parameters X and Y defined by equations (P1) and (P2) below satisfy equations (1) to (5) below.
[Equation 1]
X=100×CA/(CA+W) (P1)
[Equation 2]
Y=100×NH/(CA+NH+W) (P2)
[Equation 3]
X−51.75>0 (1)
[Equation 4]
52.75−X>0 (2)
[Equation 5]
4.25−Y> (3)
[Equation 6]
1.2245X+Y−66.367>0 (4)
[Equation 7]
−2.1569X+Y+110.27>0 (5)
A detailed description is given below of a heat storage material composition according to the present embodiment.
[Heat Storage Material Composition]
A heat storage material composition according to the present embodiment contains a main agent mixture composed of calcium chloride hexahydrate, ammonium chloride, and water.
(Main Agent Mixture)
The main agent mixture is composed of calcium chloride hexahydrate, ammonium chloride, and water. Calcium chloride hexahydrate is a heat storage substance. Calcium chloride hexahydrate generally causes a large supercooling phenomenon. Ammonium chloride is a melting point depressant.
<Calcium Chloride Hexahydrate>
As the calcium chloride hexahydrate (CaCl2.6H2O), a known compound can be used.
In the heat storage material composition according to the present embodiment, 100 mass % of the main agent mixture contains usually 45.0 to 55.0 mass %, preferably 50.0 to 54.0 mass %, more preferably 51.0 to 53.0 mass %, of calcium chloride hexahydrate. Here, 100 mass % of the main agent mixture means that the total amount of calcium chloride hexahydrate, ammonium chloride, and water is 100 mass %. When the content of calcium chloride hexahydrate is within the above-described ranges, the heat storage material composition easily has a melting point of 27° C. or lower and a high latent heat of melting at 25 to 28° C. inclusive.
<Ammonium Chloride>
As the ammonium chloride (NH4Cl), a known compound can be used.
In the heat storage material composition according to the present embodiment, 100 mass % of the main agent mixture contains usually 1.0 to 5.0 mass %, preferably 2.0 to 4.0 mass %, more preferably 2.5 to 3.5 mass %, of ammonium chloride. When the content of ammonium chloride is within the above-described ranges, the heat storage material composition easily has a melting point of 27° C. or lower and a high latent heat of melting at 25 to 28° C. inclusive.
<Water>
As the water, pure water can be used, for example.
In the heat storage material composition according to the present embodiment. 100 mass % of the main agent mixture contains usually 43.0 to 50.0 mass %, preferably 45.5 to 48.5 mass %. more preferably 46.0 to 48.0 mass %, of water. When the content of water is within the above-described ranges, the heat storage material composition easily has a melting point of 27° C. or lower and a high latent heat of melting at 25 to 28° C. inclusive.
<Composition of Heat Storage Material Composition>
A composition of the heat storage material composition is expressed using parameters X and Y defined by the following equations (P1) and (P2) with each content of calcium chloride hexahydrate, ammonium chloride, and water in 100 mass % of the main agent mixture. Specifically, when the content of calcium chloride hexahydrate is defined as CA mass %, the content of ammonium chloride is defined as NH mass %, and the content of water is defined as W mass % in 100 mass % of the main agent, CA, NH, and W are expressed using the parameters X and Y defined by the following equations (P1) and (P2).
[Equation 8]
X=100×CA/(CA+W) (P1)
[Equation 9]
Y=100×NH/(CA+NH+W) (P2)
Preferably, the parameters X and Y satisfy the following equations (1) to (5) because the heat storage material composition easily has a melting point of 27° C. or lower and a high latent heat of melting at 25 to 28° C. inclusive.
[Equation 10]
X−51.75>0 (1)
[Equation 11]
52.75−X>0 (2)
[Equation 12]
4.25−Y>0 (3)
[Equation 13]
1.2245X+Y−66.367>0 (4)
[Equation 14]
−2.1569X+Y+110.27>0 (5)
[Specific-Parameter Expressed Diagram]
(Supercooling Inhibitor)
Preferably, the heat storage material composition according to the present embodiment further includes a supercooling inhibitor because supercooling is further inhibited. The degree of supercooling is expressed in terms of supercooling degree, for example. Here. the supercooling degree means the difference between a solidification point TF and a supercooling temperature TS (TF≥TS). The supercooling temperature TS can be measured by means of the surface temperature change of a sample in a thermostatic chamber provided with a temperature measuring resistor.
Examples of the supercooling inhibitor used include at least one selected from the group consisting of strontium chloride hexahydrate, strontium hydroxide octahydrate, barium hydroxide octahydrate, strontium chloride, strontium hydroxide, barium hydroxide, calcium hydroxide, aluminum hydroxide, graphite, aluminum, titanium dioxide, hectorite, smectite clay, bentonite. laponite, propylene glycol, ethylene glycol, glycerin, ethylenediamine tetraacetic acid, sodium alkylsulfate, sodium alkylphosphate, potassium alkylsulfate, and potassium alkylphosphate. Preferably, the supercooling inhibitor is strontium hydroxide octahydrate or strontium hydroxide because supercooling is further inhibited.
Preferably, the heat storage material composition according to the present embodiment contains 100 parts by mass of the main agent mixture and 0.3 to 1.1 parts by mass of strontium hydroxide octahydrate or strontium hydroxide because supercooling is further inhibited. More preferably, the heat storage material composition according to the present embodiment contains 100 parts by mass of the main agent mixture and 0.5 to 1.0 parts by mass of strontium hydroxide octahydrate or strontium hydroxide because the supercooling degree easily falls within the range of 1 to 2.5° C.
(Supercooling Inhibitory Additive)
Preferably, the heat storage material composition according to the present embodiment further contains a supercooling inhibitory additive in addition to the supercooling inhibitor because the supercooling is further inhibited.
Examples of the supercooling inhibitory additive used include one or more substances selected from the group consisting of decanoic acid, diatomaceous earth, rayon, octadecane, sodium monododecyl phosphate, 1-propanol, polyester nonwoven fabric, polyester fiber, alumina, bromooctadecane, 2-propanol, and glycerin. Preferably, the supercooling inhibitory additive is made from one or more of the above-described substances because the supercooling degree easily falls within the range of 0.9 to 3.9° C.
As the polyester nonwoven fabric, Dilla (registered trademark) is used, for example. As the polyester fiber, disintegrated fiber of Dilla is used, for example.
There are certain preferred combinations of the supercooling inhibitor and the supercooling inhibitor additive. For example, when the supercooling inhibitor is strontium hydroxide octahydrate, it is preferable that the supercooling inhibitory additive be one or more substances selected from the group consisting of decanoic acid, diatomaceous earth, rayon, octadecane, sodium monododecyl phosphate. 1-propanol, polyester nonwoven fabric, polyester fiber, and alumina because the supercooling is further inhibited.
Preferably, the heat storage material composition according to the present embodiment contains 100 parts by mass of the main agent mixture, 0.3 to 1.1 parts by mass of strontium hydroxide octahydrate, and 0.4 to 1.1 parts by mass of the supercooling inhibitory additive because the supercooling degree easily falls within the range of 0.9 to 3.9° C. More preferably, the heat storage material composition according to the present embodiment contains 100 parts by mass of the main agent mixture, 0.5 to 1.0 parts by mass of strontium hydroxide octahydrate, and 0.4 to 1.1 parts by mass of the supercooling inhibitory additive because the supercooling degree more easily falls within the range of 0.9 to 3.9° C. Even more preferably, the heat storage material composition according to the present embodiment contains 100 parts by mass of the main agent mixture, 0.5 to 1.0 parts by mass of strontium hydroxide octahydrate, and 0.5 to 1.0 parts by mass of the supercooling inhibitory additive because the supercooling degree even more easily falls within the range of 0.9 to 3.9° C.
When the supercooling inhibitor is strontium hydroxide, it is preferable that the supercooling inhibitory additive be one or more substances selected from the group consisting of octadecane, rayon, bromooctadecane, 1-propanol, alumina, polyester nonwoven fabric, 2-propanol, glycerin, and sodium monododecyl phosphate because supercooling is further inhibited.
Preferably. the heat storage material composition according to the present embodiment contains 100 parts by mass of the main agent mixture, 0.3 to 1.1 parts by mass of strontium hydroxide, and 0.05 to 3.1 parts by mass of the supercooling inhibitory additive because the supercooling degree easily falls within the range of 0.9 to 3.9° C. More preferably. the heat storage material composition according to the present embodiment contains 100 parts by mass of the main agent mixture. 0.3 to 1.1 parts by mass of strontium hydroxide, and 0.4 to 3.1 parts by mass of the supercooling inhibitory additive because the supercooling degree more easily falls within the range of 0.9 to 3.9° C. Even more preferably, the heat storage material composition according to the present embodiment contains 100 parts by mass of the main agent mixture, 0.5 to 1.0 parts by mass of strontium hydroxide, and 0.5 to 3.0 parts by mass of the supercooling inhibitory additive because the supercooling degree even more easily falls within the range of 0.9 to 3.9° C.
(Thickener)
Preferably, the heat storage material composition according to the present embodiment further contains a thickener because the phase separation is inhibited and thus stability of the heat storage performance over a long period of time is improved. Examples of the thickener used include at least one selected from the group consisting of sodium silicate, water glass, polyacrylic acid, sodium polyacrylate, polycarboxylate polyether polymer, acrylic acid-maleic acid copolymer sodium salt, acrylic acid-sulfonic acid based monomer copolymer sodium salt, acrylamide-dimethylaminoethyl methacrylate dimethyl sulfate copolymer, acrylamide-sodium acrylate copolymer, polyethylene glycol, polypropylene glycol, superabsorbent polymer (SAP), carboxymethyl cellulose (CMC), a derivative of CMC, carrageenan, a derivative of carrageenan, xanthan gum, a derivative of xanthan gum, pectin, a derivative of pectin, starch, a derivative of starch, konjac, agar, layered silicate, and a compound substance of one or more of these substances.
(Melting Point Depressant)
The heat storage material composition according to the present embodiment can further lower the melting point of the heat storage material composition by further containing a melting point depressant. Preferably, the heat storage material composition further contains the melting point depressant because it becomes easy to adjust the melting point of the heat storage material composition to match or approximate the optimum melting point of the heat storage system. Examples of the melting point depressant used include at least one selected from the group consisting of sodium chloride, potassium chloride, sodium nitrate, sodium bromide, ammonium chloride, ammonium bromide. ammonium sulfate, ammonium nitrate, ammonium phosphate, and urea.
(Property)
The heat storage material composition according to the present embodiment has a melting point of 27° C. or lower and a latent heat of melting of 165 J/g or more at 25 to 28° C. inclusive.
In this embodiment, the melting point was measured by a differential scanning calorimeter (DSC). Specifically. for an endothermic peak at the time of melting measured by the DSC. an intersection point of a baseline on the melting start side with a tangent at a point of inflection on the melting start side of the peak was determined, and the temperature at this intersection point was taken as the melting point.
In the present embodiment, the latent heat of melting at 25 to 28° C. inclusive was measured by the DSC. Specifically, for the endothermic peak at the time of melting measured by the DSC, the latent heat of melting calculated by means of integration at 25 to 28° C. inclusive was defined as the latent heat of melting at 25 to 28° C. inclusive.
The present embodiment is described in more detail with reference to examples and comparative examples, but the present embodiment is not limited to these examples.
(Preparation of Heat Storage Material Composition)
Calcium chloride hexahydrate (CaCl2.6H2O, manufactured by KISHIDA CHEMICAL Co., Ltd., guaranteed reagent), ammonium chloride (NH4Cl, manufactured by KISHIDA CHEMICAL Co., Ltd., guaranteed reagent), and pure water were mixed in predetermined amounts to make a total of about 5 g. The amounts of calcium chloride hexahydrate, ammonium chloride, and pure water were combined in such a way that the heat storage material composition to be obtained would have a composition in Table 1. When the obtained mixture was warmed in hot water at 50° C. or higher, a heat storage material composition was obtained (Sample No. A13).
The heat storage material composition consists of calcium chloride hexahydrate, ammonium chloride, and pure water and thus consists only of what is also referred to as the main agent mixture.
The content of calcium chloride hexahydrate is defined as CA mass %, the content of ammonium chloride is defined as NH mass %, and the content of water is defined as W mass % in 100 mass % of the main agent mixture, and parameters X and Y are calculated using the following equations (P1) and (P2). The results are shown in Table 1.
[Equation 15]
X=100×CA/(CA+W) (P1)
[Equation 16]
Y=100×NH/(CA+NH+W) (P2)
The obtained parameters X and Y satisfy the following equations (1) to (5).
[Equation 17]
X−51.75>0 (1)
[Equation 18]
52.75−X>0 (2)
[Equation 19]
4.25−Y>0 (3)
[Equation 20]
1.2245X+Y−66.367>0 (4)
[Equation 21]
−2.1569X+Y+110.27>0 (5)
(Specific-Parameter Expressed Diagram)
Moreover, the obtained parameters X and Y are shown in
The composition of the heat storage material composition of Sample No. A13 was plotted in
(Measurement of melting point) An amount of 20 mg of the heat storage material composition was collected, and thermal analysis by the differential scanning calorimeter (DSC) was performed. For the obtained endothermic peak at the time of melting, an intersection point of a baseline on the melting start side with a tangent at a point of inflection on the melting start side of the peak was determined, and the temperature at this intersection point was taken as the melting point.
(Measurement of Latent Heat of Melting at 25 to 28° C. Inclusive)
For the endothermic peak at the time of melting obtained by the DSC, the latent heat of melting calculated by means of integration at 25 to 28° C. inclusive was defined as the latent heat of melting at 25 to 28° C. inclusive.
These results are shown in Table 1.
The amount of each component added was adjusted in such a way that the heat storage material composition to be obtained would have a composition in Table 1, and the heat storage material composition was prepared by the same procedure as in Example 1 (Sample Nos. A1 to A12 and A14 to A29).
(Specific-Parameter Expressed Diagram)
Compositions of the heat storage material composition of Sample Nos. A1 to A12 and A14 to A29 were plotted in
The melting point, and latent heat of melting at 25 to 28° C. inclusive of Sample Nos. A1 to A112 and A14 to A29 were measured in the same manner as in Example 1. The results are shown in Table 1.
From Table 1 and
(Preparation of Heat Storage Material Composition)
First, the main agent mixture of Example 2 (Sample No. A14) was prepared. Strontium hydroxide octahydrate Sr(OH)2.8H2O (manufactured by FUJIFILM Wako Pure Chemical Corporation) was prepared as a supercooling inhibitor.
Next, 100 parts by mass of the main agent mixture of A14, Sr(OH)2.8H2O, and as necessary a supercooling inhibitory additive were mixed in the amounts shown in Table 2, and the heat storage material composition was prepared (Sample Nos. B1 to B13).
The supercooling inhibitory additives shown in Table 2 are as follows.
Decanoic acid: manufactured by KISHIDA CHEMICAL Co., Ltd.
Diatomaceous earth: manufactured by FUJIFILM Wako Pure Chemical Corporation, average particle size 50 μm
Rayon: manufactured by UNITIKA LTD., fiber diameter 1 mm, fiber length 10 mm
Octadecane: manufactured by FUJIFILM Wako Pure Chemical Corporation
Sodium monododecyl phosphate: manufactured by Tokyo Chemical Industry Co., Ltd.
1-Propanol: manufactured by KISHIDA CHEMICAL Co., Ltd.
Dilla (nonwoven fabric): manufactured by UNITIKA LTD., polyester nonwoven fabric Dilla (registered trademark)
Dilla disintegrated fiber: manufactured by UNITIKA LTD., disintegrated fiber of polyester nonwoven fabric Dilla (registered trademark)
Alumina: alumina powder manufactured by KISHIDA CHEMICAL Co., Ltd.
The melting points of Sample Nos. B1 to B13 were measured in the same manner as in Example 1.
The supercooling degree was measured as follows.
(Measurement of Supercooling Degree)
The supercooling temperature was measured by means of the surface temperature change of a sample in a thermostatic chamber provided with a temperature measuring resistor. The supercooling degree was calculated by subtracting the supercooling temperature from the melting point.
The results are shown in Table 2 and
(Preparation of Heat Storage Material Composition)
First, the main agent mixture of Example 2 (Sample No. A14) was prepared. Strontium hydroxide Sr(OH)2 (manufactured by FUJIFILM Wako Pure Chemical Corporation) was prepared as the supercooling inhibitor. Next, 100 parts by mass of the main agent mixture of A14, Sr(OH)2, and as necessary a supercooling inhibitory additive were mixed in the amounts shown in Table 3, and the heat storage material composition was prepared (Sample No. C1 to C23).
The supercooling inhibitory additives shown in Table 3 are as follows.
Octadecane: manufactured by FUJIFILM Wako Pure Chemical Corporation Rayon: manufactured by UNITIKA LTD., fiber diameter I mm, fiber length 10 mm
Diatomaceous earth: manufactured by FUJIFILM Wako Pure Chemical Corporation, average particle size 50 μm
Bromooctadecane: manufactured by KISHIDA CHEMICAL Co., Ltd.
1-Propanol: manufactured by KISHIDA CHEMICAL Co., Ltd.
Alumina: alumina powder manufactured by KISHIDA CHEMICAL Co., Ltd.
Dilla (nonwoven fabric): manufactured by UNITIKA LTD., polyester nonwoven fabric Dilla (registered trademark) 2-Propanol: manufactured by KISHIDA CHEMICAL Co., Ltd.
Glycerin: manufactured by KISHIDA CHEMICAL Co., Ltd.
Sodium monododecyl phosphate: manufactured by Tokyo Chemical Industry Co., Ltd.
MgCl2: magnesium chloride manufactured by KISHIDA CHEMICAL Co., Ltd.
The melting point and supercooling degree of Sample Nos. C1 to C23 were measured in the same manner as in Example 24. The results arc shown in Table 3 and
From Table 2, when I% of strontium hydroxide octahydrate Sr(OH)2.8H2O was added to the heat storage material composition, the supercooling degree was found to be 2.1° C. When each of the additives and strontium hydroxide octahydrate were combined and added to the heat storage material composition, the supercooling degree was found to be 0.9 to 1.9° C. In particular. when 0.5% of octadecane and 1.0 parts by mass of strontium hydroxide octahydrate were added to the heat storage material composition in combination, the supercooling degree was found to be 0.9 to 1.9° C.
From Table 3, when 1% of strontium hydroxide Sr(OH)2 was added to the heat storage material composition, the supercooling degree was found to be 2.5° C. When each of the additives and strontium hydroxide were combined and added to the heat storage material composition, the supercooling degree was found to be 1 to 3.9° C. The entire contents of Japanese Patent Application No. 2020-045192 (tiled on Mar. 16. 2020) are incorporated herein by reference.
Although the present embodiment has been described above, the present embodiment is not limited thereto, and various modifications are possible within the scope of the gist of the present embodiment.
The present invention is capable of providing a heat storage material composition having a melting point of 27° C. or less and a high latent heat of melting in a narrow melting temperature range. Note that the above-described latent heat of melting in the narrow melting temperature range was specifically defined as the latent heat of melting at 25 to 28° C. inclusive.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-045192 | Mar 2020 | JP | national |
The present application is a continuation of International Application No. PCT/JP2021/009160, filed on Mar. 9, 2021, and based upon and claims the benefit of priority from Japanese Patent Application No. 2020-045192, filed on Mar. 16, 2020, the entire contents of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2021/009160 | Mar 2021 | US |
| Child | 17945535 | US |
