JP2006096898A - Heat storage material composition containing polyalkylene glycol - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an economical and safe heat storage material composition easily controllable of temperature by improving decrease of latent heat amount of the heat storage material comprising water-polyalkylene glycol. <P>SOLUTION: The heat storage material composition comprises an aqueous solution of at least one polyalkylene glycol-insoluble and water-soluble salt and a polyalkylene glycol such as polyethylene glycol, and a heat storing device using the material is provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat storage material composition containing at least one aqueous solution of water-soluble salts insoluble in polyalkylene glycol, and polyalkylene glycol, and a heat storage device using the same.

Thermal energy is extremely important energy for industry and life, and most of it is derived from combustion of fuel materials and electrical energy. In recent years, the use of solar heat and waste heat has attracted attention because of the effective use of earth resources. However, since the generation time and amount of heat energy are unstable, the heat energy is used effectively. Things were limited. If such heat energy can be temporarily stored, the heat energy can be effectively used. For this reason, various heat storage materials have been developed as temporary storage means for thermal energy. The heat storage material is roughly classified into a sensible heat storage material using a sensible heat material and a latent heat storage material using a latent heat material.
Conventionally, heat storage in the negative temperature range has been achieved simply by mixing water and a substance that is soluble in water, so it could be performed relatively easily using water. With respect to the heat storage material in the area, problems such as safety and cost have occurred and it has been relatively difficult.

A sensible heat storage material uses the heat capacity of a substance (in the case of a hot water tampo, water) like a hot water tampo, and even though it has been used by humans for a long time, it is difficult to control the temperature. There are drawbacks that it is difficult to control the temperature in the region and that a large device is required to secure a large heat capacity.
In addition, latent heat-type heat storage materials use phase transitions such as melting of substances, and a large amount of thermal energy can be stored in a narrow temperature range near the phase transition temperature compared to sensible heat-type heat storage materials, so temperature control Can be relatively easy, and a small-capacity and compact device can be obtained. For this reason, attention has been paid to the development of latent heat storage materials. For example, heat storage materials using sodium sulfate decahydrate (melting point 32 ° C), sodium acetate trihydrate (melting point 58 ° C), quaternary ammonium salt hydrate heat storage materials, organic compound paraffin heat storage materials, etc. have been developed. It is coming. Furthermore, those using aliphatic hydrocarbons or esters have been developed, and some have been put into practical use for floor heating or human body contact heating. Hydrated salt heat storage materials have higher heat storage density and nonflammability compared to other organic heat storage materials, but they tend to cause phase separation and supercooling due to repeated melting and solidification. Therefore, there is a disadvantage that it is not practical unless a phase separation inhibitor or a supercooling inhibitor is added. Furthermore, since the corrosiveness with respect to a metal is large, there also exists a fault that sufficient consideration is required for the container material.

  On the other hand, polyalkylene glycols such as polyethylene glycol, unlike other organic materials such as paraffin, have a variety of molecular weight distributions, have unique freezing points depending on the molecular weight, are easy to control temperature, and are chemically stable. It has the characteristic that there is almost no toxicity and irritation. For this purpose, polyethylene glycol is used for heat treatment (see Patent Documents 1 and 2), used as a heat storage material for a heat insulating mat for pets (see Patent Document 3), and used as an animal heat retaining agent. A method (see Patent Document 4) has been reported. However, polyethylene glycol having an average molecular weight of less than 1000 is advantageous in that it can provide a heat storage material having a freezing and melting point of about 0 ° C. to 20 ° C. However, it has a low flash point and is a dangerous material in the Fire Service Act. It is not only dangerous for use as a material, but also it is fluidized at high temperatures and has poor shape retention, so it can be coated with a reversible crosslinkable polymer (see Patent Document 5), or a monomer component is polymerized (patented) Reference 6) has been reported. On the other hand, a method of encapsulating a heat storage material such as polyethylene glycol in a capsule has been proposed in order to improve fluidity when solidified into a solid state (see Patent Document 7). Furthermore, when polyethylene glycol is repeatedly used as a heat storage material, deterioration such as a decrease in the amount of heat storage occurs within a short period of time, and as a method to prevent this, a method of adding phenols or amines to polyethylene glycol Has been proposed (see Patent Document 8). In addition, since polyethylene glycol is hygroscopic, it contains water during use and not only lowers the freezing point and latent heat but also causes overcooling. In order to prevent this, a method of adding anhydrous carbonate or zeolite to polyethylene glycol has been reported (see Patent Document 9).

  Thus, polyalkylene glycol such as polyethylene glycol has excellent properties as a heat storage material, but has many problems as a practical heat storage material. However, polyalkylene glycols such as polyethylene glycol can be mixed with water at an arbitrary ratio, the solidification and melting point can be changed according to the mixing ratio, and the specific gravity is close to water and hardly causes phase separation with water. It is known. For this reason, a water-polyalkylene glycol heat storage material in which water is mixed has also been proposed. For example, a method of changing the mixing ratio with water and using a water-polyethylene glycol-based heat storage material as both heat storage materials for cooling and heating has been proposed (see Patent Document 10). Furthermore, it has also been reported that the heat storage amount of polyethylene glycol increases by adding water, an inorganic compound, or an organic compound (see Patent Document 11). However, if the added amount is 20% or more, it is said that toxicity and supercooling phenomenon occur. Similarly, it has been reported that the apparent heat of fusion is increased by adding an equilibrium moisture absorption amount of water to polyethylene glycol. However, the degree of supercooling increases as the amount of water added increases. (See Patent Document 12).

  Since water is cheap and safe, water-polyalkylene glycol-based heat storage materials such as water-polyethylene glycol are preferable not only in terms of price but also in terms of safety. It has been found that adding water to polyethylene glycol reduces the latent heat amount of the polyethylene glycol heat storage material. This decrease in latent heat applies not only to water but also to other heat storage materials. In order to put the water-polyalkylene glycol-based heat storage material into practical use, it is indispensable to overcome this drawback. However, there is no technology for overcoming this disadvantage.

JP-A-8-280730 JP-A-7-328054 JP 2004-215560 A JP 2004-16091 A Japanese Patent Application Laid-Open No. 2002-114973 JP-A-11-80723 JP-A-7-289579 JP 61-64782 A JP-A 62-199680 JP-A-63-161333 JP 59-140283 A JP 59-174683 A

  As described above, polyalkylene glycols such as polyethylene glycol are excellent heat storage materials. However, when providing heat storage materials having various latent heat utilization temperature zones, it is preferable to add inexpensive and safe water. However, adding water not only increases the degree of supercooling, but also changes the amount of latent heat. Although it is reported that the heat of fusion increases due to the addition of water (see Patent Documents 11 and 12), this is performed by mixing different heat storage materials, resulting in an increase in the amount of latent heat in the entire temperature range, The amount of latent heat in a specific temperature range is reduced. That is, there is a drawback that the amount of latent heat of polyethylene glycol itself used as a heat storage material decreases. Specifically, polyethylene glycol having a molecular weight of 2700-3400 has a melting point of 53-57 ° C. and a heat of fusion of 180 J / g, but when 20% by weight of water is added thereto, the melting point is 40.5. It becomes 6 degreeC and 61.8 J / g of fusion heat. At this time, the melting and solidification temperature of water is not 0 ° C., but the freezing point is lowered. That is, the heat storage material deviates from the normal use area. The present inventors have found that the amount of latent heat decreases when water is added to polyethylene glycol and the like, and it is difficult to put it to practical use unless this problem is solved. It aims at improving the fall of the amount of latent heat in a thermal storage material.

  In order to solve the above-mentioned problems, the present inventors have intensively studied, and as a result, such a decrease in latent heat occurs because polyalkylene glycol is very soluble in water. Because most of the polyalkylene glycol dissolved in water does not solidify, the knowledge that the latent heat amount with respect to the proportion of polyalkylene glycol dissolved in water is low, Based on this finding, by adding a salt that is insoluble in polyalkylene glycol and easily soluble in water to water and mixing and dissolving it, the solubility of polyalkylene glycol in water can be increased. It has been found that, as a result, the melting and freezing point can be sufficiently changed, and at the same time, a decrease in latent heat can be prevented.

That is, the present invention relates to a heat storage material composition containing at least one aqueous solution of a water-soluble salt that is insoluble in polyalkylene glycol and polyalkylene glycol.
The present invention also relates to a heat storage device using the above-described heat storage material composition of the present invention as a heat storage material.
Furthermore, the present invention provides a heat storage method using the above-described heat storage material composition of the present invention as a heat storage material.

Patent Document 11 (Japanese Patent Laid-Open No. 59-140283) discloses that the heat of fusion is increased by adding water, an inorganic compound or an organic compound to polyethylene glycol, and dissolving and mixing in polyethylene glycol. . However, according to experiments by the present inventors, it was found that the heat of fusion decreases when a substance that dissolves in polyethylene glycol is added. For example, the heat of fusion of polyethylene glycol 1540 (Daiichi Kogyo Seiyaku Co., Ltd.) (average molecular weight 1300-1600) is 155 J / g (about 37 cal / g) according to the product catalog of Daiichi Kogyo Seiyaku. It was found that the addition of 17% by weight of water not only gave 70.93 J / g (about 17 cal / g), but also caused a supercooling phenomenon. Similarly, the heat of fusion of polyethylene glycol 4000 (Daiichi Kogyo Seiyaku Co., Ltd.) (average molecular weight 2700-3400) is 180 J / g (about 43 cal / g) according to the product catalog of Daiichi Kogyo Seiyaku, It was found that when 20% by weight of water was added to this, not only it became 76.44 J / g (about 18 cal / g) but also a supercooling phenomenon occurred.
When the present inventors examined the cause of such a result, at the melting point of polyalkylene glycol (for example, about 4 to 8 ° C. for 100% polyethylene glycol 400 and 56 to 61 ° C. for polyethylene glycol 10000), Water is a temperature that normally exists as liquid water, and it is considered that the heat of fusion of water does not contribute significantly to the heat of fusion at the melting point of the water-polyalkylene glycol system. It was thought that the heat of fusion of the polyalkylene glycol was decreased by the amount of. If so, reducing the solubility of the polyalkylene glycol in water should reduce the amount of polyalkylene glycol dissolved in the water and restore the heat of fusion accordingly.

  Accordingly, the present inventors prepared various aqueous salts of polyethylene glycol 4000 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as polyalkylene glycol, prepared a mixture with the polyethylene glycol 4000, and melted them. The spot and heat of fusion were measured. The results are shown in Table 1 below.

When 20% by mass of water is added to polyethylene glycol 4000 (second in Table 1), the melting point decreases by about 16 ° C. and the heat of fusion decreases by about 100 J / g. When 30% by weight of saturated saline was added instead of water (third in Table 1), the melting point further decreased, but surprisingly the amount of heat of fusion should be about 70 J / g. It became clear that it was possible. Since the solubility of sodium chloride is about 26 g at 40 ° C., the amount of sodium chloride in the composition of polyethylene glycol to which 30% by mass of saturated saline is added is about 7.8% by mass, and water is about 22.2%. The amount of water was not changed so much, but it was found that the heat of fusion recovered by about 40% (106.48 / 76.44 × 100) due to the presence of salt.
This result proves that the above-mentioned assumption of the present inventors is correct. That is, in a water-polyethylene glycol-based heat storage material composition, at least one salt that is insoluble in polyethylene glycol and easily soluble in water is added and dissolved in water. It has been found that the reduction in heat of fusion of polyethylene glycol that was reduced by the addition of can be recovered.
In Table 1 described above, the results when other salts are used are also described. From these results, there is a slight difference in the degree of recovery, which is considered to be due to the difference in the heat of fusion of the added salts and the degree of compatibility with polyethylene glycol.
In the case of magnesium chloride (sixth in Table 1), the value is lower than that in the case of 20% by mass of water, but this is because the amount of the aqueous solution is increased to 45% by mass, The heat of fusion is so small that it cannot be measured in the system of polyethylene glycol 55% -water 45%. When polyethylene glycol 4000 is 70% by mass and water is 30% by mass, the heat of fusion is 18.96 J / g. The melting point is 16.7 ° C., and it has been clarified that the heat of fusion is 68.9 J / g, which is much higher than that of simply mixing with water.
Similarly, the results for polyethylene glycol 10000 (Daiichi Kogyo Seiyaku Co., Ltd.) (see Table 2 below) and polyethylene glycol 1540 (Daiichi Kogyo Seiyaku Co., Ltd.) (see Table 3 below) are shown in Table 2 below. And Table 3 respectively.

As is clear from the above results, by adding salts to the water-polyalkylene glycol system, it is possible to prevent a decrease in heat of fusion of the polyalkylene glycols due to mixing of water.
The polyalkylene glycol in the present invention is not particularly limited as long as it can be mixed with water, but the alkylene group in the polyalkylene glycol is preferably a straight chain having 2 to 6, preferably 2 to 3 carbon atoms. And those consisting of a linear or branched alkylene group. Preferred polyalkylene glycols of the present invention include polyethylene glycol, polypropylene glycol, poly (methyl-ethylene) glycol, polybutylene glycol and the like, but polyethylene glycol or polypropylene glycol is more preferred.

In the heat storage material composition of the present invention, at least one aqueous solution of a water-soluble salt that is insoluble in polyalkylene glycol, preferably polyethylene glycol, is an aqueous solution obtained by mixing the salt with water and dissolving it. It is preferable that polyalkylene glycol and water are mixed and dissolved, and the salts are added and mixed to dissolve them. That is, the heat storage material composition of the present invention can be referred to as a heat storage material composition that is insoluble in polyalkylene glycol and contains at least one water-soluble salt, water, and polyalkylene glycol. .
The salt of the present invention is not particularly limited as long as it is substantially insoluble in polyalkylene glycol, preferably polyethylene glycol, dissolves in water, and at least a part of the salt is substantially ionized in an aqueous solution. Although there is no particular limitation, salts having a solubility of preferably 5 g or more, preferably 10 g or more, more preferably 15 g or more per 100 g of water at 20 ° C. can be mentioned.
The salts of the present invention may be organic salts or inorganic salts as long as they have solubility in water as described above. Preferred salts of the present invention include alkali metal salts such as sodium salt, potassium salt and lithium salt, and alkaline earth metal salts such as magnesium salt and calcium salt, with alkali metal salts being more preferred. These alkali metal salts or alkaline earth metal salts may be organic acid salts such as carboxylic acid and sulfonic acid, and may be inorganic acid salts such as halogenated acid, carbonic acid, sulfuric acid and nitric acid. . Preferred salts include at least one selected from the group of alkali metal halides, alkaline earth metal halides, ammonium halides, alkali metal carbonates, alkaline earth metal carbonates, and alkali metal carboxylates, for example Sodium chloride, potassium chloride, lithium chloride, magnesium chloride, sodium carbonate, potassium carbonate, lithium carbonate, magnesium carbonate, potassium acetate, sodium acetate and the like. Sodium chloride is preferable from the viewpoint of safety and price.

There is no restriction | limiting in particular in the usage-amount of these salts, Generally it is so preferable that there are many, and it can use to the quantity used as saturated aqueous solution. Although it can be used even in an amount that makes it a dilute aqueous solution, a larger amount is usually preferred because it reduces the solubility of polyalkylene glycol in water.
According to the knowledge of the present inventors, the molar concentration of the aqueous solution of the present invention considering the ionic strength greatly contributes to the latent heat amount and the melting point, depending on how many moles of molecules are present in the aqueous solution. The melting heat and melting point are almost determined. For example, Table 4 shows the measurement results of heat of fusion (J / g) and melting point (° C.) of an aqueous solution of 80% by mass polyethylene glycol 4000 using various salts.

  As shown in Table 4, it can be seen that both the heat of fusion and the melting point of the sodium chloride and the potassium chloride have almost the same value if the concentration is the same as 3.42 mol / kg. . In addition, in the case of potassium carbonate, three ions of two potassium ions and one carbonate ion are generated from one molecule, and therefore 2.28 mol / kg is able to absorb two ions such as sodium chloride. This is considered to correspond to 3.42 mol / kg (2.28 × 1.5 = 3.42) of the salt produced. Table 4 clearly shows that the heat of fusion and the melting point of potassium carbonate 2.28 mol / kg are almost the same as those of sodium chloride. Such a relationship between the molar mass and the heat of fusion can be particularly observed for alkali metal salts. For example, when more detailed data is examined for sodium chloride, the following Table 5 is obtained.

This data is obtained when the concentration of NaCl in the NaCl aqueous solution is changed to each value shown in Table 5 with a constant blending ratio of 70% by mass of polyethylene glycol 4000 (Daiichi Kogyo Seiyaku Co., Ltd.) and 30% by mass of the NaCl aqueous solution. This shows the results.
A graph of these results is shown in FIG. FIG. 1 shows the relationship between NaCl concentration (mol / kg) and heat of fusion (J / g) in Table 5. These graphs also clarify that the heat of fusion depends on the molar concentration of NaCl.
This indicates that the heat storage material composition of the present invention greatly depends on its molar concentration rather than the molecular species of the salt used, and it is possible to use a cheaper salt. .
The preferred molar molar concentration of the salt in the aqueous solution of the present invention is the concentration of the salt that generates two ions, 1 mol / kg or more, preferably 2 mol / kg or more, 3 mol / kg or more to saturation of each salt. The range can be up to the concentration.

In addition, with regard to various concentrations and temperatures of saturated aqueous solutions, it is usually important that the salt crystals do not precipitate even at the melting point and freezing point of the heat storage material composition of the present invention, and the freezing point of the composition is taken into consideration. In such a manner, an amount of a saturated aqueous solution can be added.
Although there is no restriction | limiting in particular as said compounding quantity of the aqueous solution in the thermal storage material composition of this invention, Preferably the aqueous solution of salt is 5 to 60 weight% with respect to the whole quantity of a thermal storage material composition, More preferably, it is 10 to 10 weight percent. It is about 60% by mass and 10 to 45% by mass. As preferable water content, 3-50 mass%, for example, More preferably, about 10-50 mass%, 20-40 mass% is mentioned.

The molecular weight of the polyalkylene glycol in the heat storage composition of the present invention is not particularly limited as long as it is 200 or more, but preferably has a molecular weight of about 200 to 20,000, 200 to 10,000, and 1,000 to 10,000. For example, the molecular weight of polyethylene glycol is not particularly limited as long as the molecular weight is 200 or more, but preferably 900 to 20000, 900 to 10,000, more preferably about 1300 to 10,000.
The heat storage material composition of the present invention can further contain other additives as the heat storage material. Examples of such additives include corrosion inhibitors, antioxidants, antistatic agents, colorants, and antifungal agents. Moreover, in order to improve shape retention and fluidity, it may be granulated and the surface thereof may be coated with a crosslinkable polymer or the like, or it may be encapsulated.

The heat storage material composition of the present invention can be used as a heat storage material in various heat storage devices such as various types of heat retaining devices, air conditioning equipment, and heat recovery systems. The heat storage material composition of the present invention can be applied to various devices in the same manner as the device using conventional polyethylene glycol as the heat storage material. In application, since the heat storage material composition of the present invention contains water, it is necessary to pay attention to prevention of corrosion of metal parts of the apparatus.
A synthetic resin such as polyethylene or nylon is preferably used as the container for the heat storage material composition of the present invention, but is not limited thereto.

  Since the present invention can be used as a mixture with a large amount of water, it has a specific melting point in the temperature range of 0 ° C. or more and 60 ° C. or less, has a high latent heat amount, and further is prevented from being overcooled. A safe heat storage material composition is provided. In the patent documents mentioned above, it is said that supercooling increases as water is added in a large amount. However, since the heat storage material composition of the present invention contains salts, it prevents supercooling due to the mixing of water. It has the unexpected effect of being able to. Moreover, the heat of fusion and melting point in the heat storage material composition of the present invention largely depend on the content thereof, not the type of salts to be used, and it is possible to use cheaper salts. Furthermore, the heat storage material composition of the present invention can contain a large amount of water, has low flammability, can greatly reduce the risk of fire, and can be made of highly safe materials such as water and salt. It can be used and can be used extremely safely even in daily life.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited to these Examples.

A 4.54 mol / kg aqueous solution of sodium chloride was prepared, and 30 g of this aqueous solution and 70 g of polyethylene glycol 4000 (Daiichi Kogyo Seiyaku Co., Ltd.) were mixed, stirred and dissolved to prepare a heat storage material composition.
The amount of latent heat of this heat storage material composition was measured using DSC SEIKO 6200 (manufactured by Seiko Instruments Inc.). The results are shown in Table 1.

A 7.24 mol / kg aqueous solution of potassium carbonate was prepared, and 25 g of this aqueous solution and 75 g of polyethylene glycol 4000 (Daiichi Kogyo Seiyaku Co., Ltd.) were mixed, stirred and dissolved to prepare a heat storage material composition.
The amount of latent heat of this heat storage material composition was measured in the same manner as in Example 1. The results are shown in Table 1.

A 8.28 mol / kg aqueous solution of potassium acetate was prepared, and 40 g of this aqueous solution and 60 g of polyethylene glycol 4000 (Daiichi Kogyo Seiyaku Co., Ltd.) were mixed, stirred and dissolved to prepare a heat storage material composition.
The amount of latent heat of this heat storage material composition was measured in the same manner as in Example 1. The results are shown in Table 1.

A 3.70 mol / kg aqueous solution of magnesium chloride was prepared, and 45 g of this aqueous solution and 55 g of polyethylene glycol 4000 (Daiichi Kogyo Seiyaku Co., Ltd.) were mixed, stirred and dissolved to prepare a heat storage material composition.
The amount of latent heat of this heat storage material composition was measured in the same manner as in Example 1. The results are shown in Table 1.

A 4.54 mol / kg aqueous solution of sodium chloride was prepared, and 30 g of this aqueous solution and 70 g of polyethylene glycol 10000 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: average molecular weight 9300-12500) were mixed, stirred and dissolved to obtain a heat storage material composition. Was prepared.
The amount of latent heat of this heat storage material composition was measured in the same manner as in Example 1. The results are shown in Table 2.

A 3.7 mol / kg aqueous solution of magnesium chloride was prepared, and 30 g of this aqueous solution and 70 g of polyethylene glycol 10000 (Daiichi Kogyo Seiyaku Co., Ltd.) were mixed, stirred and dissolved to prepare a heat storage material composition.
The amount of latent heat of this heat storage material composition was measured in the same manner as in Example 1. The results are shown in Table 2.

A 4.54 mol / kg aqueous solution of sodium chloride was prepared, and 25 g of this aqueous solution and 75 g of polyethylene glycol 1540 (Daiichi Kogyo Seiyaku Co., Ltd.) were mixed, stirred and dissolved to prepare a heat storage material composition.
The amount of latent heat of this heat storage material composition was measured in the same manner as in Example 1. The results are shown in Table 3.

A 8.23 mol / kg aqueous solution of potassium acetate was prepared, and 35 g of this aqueous solution and 65 g of polyethylene glycol 1540 (Daiichi Kogyo Seiyaku Co., Ltd.) were mixed, stirred and dissolved to prepare a heat storage material composition.
The amount of latent heat of this heat storage material composition was measured in the same manner as in Example 1. The results are shown in Table 3.

A 3.42 mol / kg aqueous solution of sodium chloride was prepared, and 20 g of this aqueous solution and 80 g of polyethylene glycol 4000 (Daiichi Kogyo Seiyaku Co., Ltd.) were mixed, stirred and dissolved to prepare a heat storage material composition.
The amount of latent heat of this heat storage material composition was measured in the same manner as in Example 1. The results are shown in Table 4.

A 3.42 mol / kg aqueous solution of potassium chloride was prepared, and 20 g of this aqueous solution and 80 g of polyethylene glycol 4000 (Daiichi Kogyo Seiyaku Co., Ltd.) were mixed, stirred and dissolved to prepare a heat storage material composition.
The amount of latent heat of this heat storage material composition was measured in the same manner as in Example 1. The results are shown in Table 4.

A 2.28 mol / kg aqueous solution of potassium carbonate was prepared, and 20 g of this aqueous solution and 80 g of polyethylene glycol 4000 (produced by Daiichi Kogyo Seiyaku Co., Ltd.) were mixed, stirred and dissolved to prepare a heat storage material composition.
The amount of latent heat of this heat storage material composition was measured in the same manner as in Example 1. The results are shown in Table 4.

Polyethylene glycol 4000 (Daiichi Kogyo Seiyaku Co., Ltd.) 70% by mass and NaCl aqueous solution 30% by mass, the NaCl concentration in the NaCl aqueous solution was 0 mol / kg, 1.02 mol / kg, 1.71 mol / kg, respectively. A heat storage material composition was prepared in the same manner as in Example 1 with kg, 2.38 mol / kg, 3.42 mol / kg, or 4.54 mol / kg. The amount of latent heat of this heat storage material composition was measured in the same manner as in Example 1. The results are shown in Table 5. Moreover, these results are graphed and shown in FIGS.

  As effective utilization of thermal energy is extremely important for preventing global warming, the heat storage material composition of the present invention has a large amount of latent heat, is inexpensive, and has extremely high safety. Is also extremely useful.

FIG. 1 shows the relationship between the molar concentration of NaCl aqueous solution and the heat of fusion (J / g) of the heat storage material composition of the present invention when NaCl is used as the water-soluble salt of the heat storage material composition of the present invention. It is a graph which shows.

Claims (11)

  A heat storage material composition comprising at least one aqueous solution of a water-soluble salt that is insoluble in polyalkylene glycol and polyalkylene glycol.   The heat storage material composition according to claim 1, wherein the aqueous salt solution is an aqueous solution containing 1 mol or more of salt per kg of water.   The heat storage material composition according to claim 1 or 2, wherein the aqueous salt solution is a saturated aqueous solution of the salt.   The heat storage material composition according to any one of claims 1 to 3, wherein the salt is an alkali metal salt or an alkaline earth metal salt.   The heat storage material composition according to any one of claims 1 to 4, wherein the salt is a salt of an inorganic compound.   The heat storage material composition according to any one of claims 1 to 4, wherein the salt is an organic carboxylate.   The salt is at least one selected from the group consisting of an alkali metal halide, an alkali earth metal halide, an alkali metal carbonate, an alkaline earth metal carbonate, and an alkali metal carboxylate. The heat storage material composition as described.   The heat storage material composition according to any one of claims 1 to 7, wherein the aqueous salt solution is 5 to 60% by weight based on the total amount of the heat storage material composition.   The heat storage material composition according to any one of claims 1 to 8, wherein the polyalkylene glycol is polyethylene glycol or polypropylene glycol.   The molecular weight of polyalkylene glycol is 1000 or more, The heat storage material composition in any one of Claims 1-9. The thermal storage apparatus which used the thermal storage material composition in any one of Claims 1-10 as a thermal storage material.

Images