JP2000063811A - Heat accumulator composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compsn. contg. trimethylol ethane (A), water (B), and a compd. having a sulfonyl group in a moleclule (C), and having a phase transition point near room temp., a large heat accumulation density, and an excellent repetition stability without phase separation. SOLUTION: For component C, saccharin sodium, sulfosalicylic acid, and sulfolane are suitable. The contents of each component are component A: 20-80 wt.%, component B: 19-50 wt.%, and component C: 1-50 wt.%, and weight ratio of component A to component B (A/B) is pref. 75/25-50/50. Phase transition point which indicates the greatest latent heat is pref. 5-15 deg.C. The phase transition point of trimethylol ethane/water system heat accumulator is controlled to a desired temp. by adding a water soluble org. compd. having at least one non-covalent electron pair in a molecule to the mixture of trimethylol ethane and water. This accumulator compsn. has a phase transition point of 5-25 deg.C and is used favorably as a passive type heat accumulator or a cold accumulator in the field of construction material.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a heat storage material composition. More specifically, it relates to a heat storage material composition containing trimethylolethane and water, which utilizes latent heat of phase transition.

[0002]

2. Description of the Related Art Latent heat type heat storage materials have various advantages such as high heat storage density, constant phase change temperature and stable heat extraction temperature as compared with sensible heat type heat storage materials. Has been put to practical use. As the main components of this latent heat storage material, ice, sodium sulfate decahydrate, calcium chloride hexahydrate, sodium acetate trihydrate, etc. are known. A typical example of practical application of these latent heat storage materials is an ice heat storage system that uses late-night power.

Further, a heat storage material having a phase change temperature of 20 to 30 ° C., which is close to the living environment temperature, has been earnestly studied for the purpose of greenhouse and floor heating. As its main component, sodium sulfate decahydrate or calcium chloride hexahydrate is often used, and both can be said to be inexpensive and excellent heat storage material raw materials because of their large heat storage densities. However, when sodium sulfate decahydrate melts above the melting point, it separates into two phases, anhydrous sodium sulfate and a saturated aqueous solution of sodium sulfate, and when it solidifies, it only forms on the surface of the precipitated anhydrous sodium sulfate decahydrate. However, there is a problem that the heat storage amount is significantly reduced. This is a phenomenon called phase separation, and is caused by the fact that sodium sulfate decahydrate does not completely become an aqueous solution when it is melted, and so-called harmonic melting does not occur.

Further, although calcium chloride hexahydrate melts in harmony, when it is repeatedly used, a low-order hydrated salt having a higher melting point is produced, and an insoluble matter precipitates like sodium sulfate decahydrate. However, there is still a problem that the amount of heat storage decreases. As the above hydrate heat storage material, when it is melted, it becomes a state of complete melting to become an aqueous solution, and,
It is desirable that there be no hydrates with different melting points. However, an ideal hydrate heat storage material having such performance is not known.

Further, as a heat storage material having a phase transition point of 20 ° C. or lower which can be used for cooling, it is composed of sodium sulfate decahydrate / ammonium chloride / sodium chloride / ammonium sulfate and has a melting temperature of 8 to 12 ° C. A composition is known (JP-A-7-48564). Although the composition has an excellent heat storage density and safety, it inherently has the above-mentioned problem of phase separation, and in order to secure long-term repetitive stability, a water-absorbing resin or the like as a phase separation inhibitor is used. Must be added, and it is difficult to completely prevent phase separation.

On the other hand, trimethylolethane (also known as pentaglycerin) has a melting point of about 200 ° C. and a solid phase transition point of 8
It is a substance that has a sublimability of 9 ° C and has a solid phase transition heat of 3
It is expected to be a relatively high heat storage material for high temperature of 3.2 cal / g, and several reports have been made regarding its physical properties. For example, Japanese Patent No. 2581708 discloses that trimethylolethane hydrate has a melting point in the range of 21 to 35 ° C. In addition, Laugt, M et al. Reported that trimethylolethane tetrahydrate had a melting point of 29.8 ° C. and a latent heat of fusion of 185 kJ / kg (Powder Diffr. (1991), 6 (4) ), 190-193).

[0007]

As described above, trimethylolethane can be expected as a heat storage material for high temperature, but according to the study by the present inventors, a heat storage material of trimethylolethane and water. However, there is a problem that the supercooling phenomenon is large, and there is no report that it is actually put to practical use.

Therefore, an object of the present invention is to provide a heat storage material composition having a phase transition point at 5 to 25 ° C., which is usable for passive heat storage in the field of building materials, etc., is stable without phase separation, and has a high heat storage density. To provide.

[0009]

Means for Solving the Problems As a result of intensive studies in view of the above problems, the present inventors added a water-soluble organic compound having at least one unshared electron pair in the molecule to a mixture of trimethylolethane and water. As a result, they have found that the phase transition point of the trimethylolethane / water-based heat storage material can be adjusted to a desired temperature, and have reached the present invention.

That is, the gist of the present invention is to provide a heat storage material composition containing three components: (A) trimethylolethane, (B) water and (C) a compound having a sulfonyl group in the molecule. Regarding

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
The feature of the present invention resides in that the trimethylolethane / water-based heat storage material composition contains a compound having a sulfonyl group in the molecule to obtain a heat storage material composition having a lower melting point. Incidentally, such a compound is preferably water-soluble,
The solubility is not particularly limited, but a compound capable of dissolving 1 g or more in 100 g of pure water at 25 ° C. is more preferable.

Examples of the compound having a sulfonyl group in the above molecule include sodium saccharin, potassium saccharin, sulfolane, dimethyl sulfoxide and the like. Further, saccharin sodium, sulfosalicylic acid, or sulfolane is particularly exemplified from the viewpoint of safety, economy, crystallinity, or melting point lowering effect. The compounds corresponding to the above may be used in combination of two or more kinds.

Next, the composition of the heat storage material composition of the present invention is not particularly limited, but usually 20 to 80% by weight of the component (A) trimethylolethane and the component (B).
Water of 19 to 50% by weight, and the compound having a sulfonyl group in the molecule of component (C) is 1 to 50% by weight, preferably 30 to 70% by weight of component (A) and component (B).
Is 20 to 40% by weight, and the component (C) is 5 to 40% by weight.

In the above, if the content of trimethylolethane of the component (A) is less than 20%, the absolute amount of trimethylolethane present as a hydrate in the composition is small, and the heat storage density is lowered. When it exceeds 80%, the amount of trimethylolethane that has not completely melted is increased and the heat storage amount is decreased. If the water content of the component (B) is less than 19%, the absolute amount of trimethylolethane present as a hydrate will be small, and the heat storage density will decrease.
If it exceeds, a part or all of the trimethylolethane hydrate produced will be dissolved in excess water, and the heat storage amount due to hydrate formation will decrease. Further, if the content of the water-soluble organic compound having at least one unshared electron pair of the component (C) in the molecule is less than 1%, the effect of adjusting the phase transition point of the hydrate of trimethylolethane decreases, and conversely 50 If it exceeds%, the absolute amount of trimethylolethane hydrate produced becomes small, and the heat storage density decreases.

The weight ratio (A / B) of the component (A) and the component (B) is preferably 75/25 to 50/5.
The range is 0. If it exceeds 75/25, the amount of the component (A) that cannot become a hydrate increases, so that the heat storage density decreases. On the other hand, when it is less than 50/50, a part or all of the produced (A) hydrate is dissolved in excess water, and the heat storage amount due to the hydrate production is reduced.

In the heat storage material composition of the present invention described above, the phase transition point showing the maximum latent heat amount is usually in the range of 5 to 25 ° C., more preferably in the range of 10 to 23 ° C., and most preferably in the range of 15 to 20 ° C.
However, the range is not limited to this. If the phase transition point showing the maximum latent heat amount is less than 5 ° C., the range of exhaust heat of heat that is usually possible is exceeded. Further, when the phase transition point showing the maximum latent heat amount exceeds 25 ° C., the heat cannot be stored in a short time at a normal environmental heat temperature.

In some cases, a problem of so-called supercooling may occur in which crystallization does not occur even when cooled below the phase transition point. To prevent this, a supercooling inhibitor is added if necessary. You may keep it. Preferred examples of the supercooling inhibitor include inorganic salts or hydrated inorganic salts such as sodium carbonate, sodium carbonate monohydrate, sodium pyrophosphate, sodium pyrophosphate decahydrate, and tricalcium phosphate.

Further, the heat storage material composition of the present invention may contain a thickener, if necessary. Examples of the thickener include water-insoluble water-absorbing polymer, sodium polyacrylate, polyacrylamide, polyglycerin, carboxymethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, alginate, xanthan gum, galarginan, gelatin and agar, but are not limited thereto. It will not be done. The blending amount of these thickeners is usually 0.1 to 5 parts by weight with respect to 100 parts by weight of the total amount of the three components (A) to (C) of the heat storage material composition. Furthermore, the heat storage material composition of the present invention includes antioxidants such as phenols, amines, hydroxyamines, chromate salts, polyphosphate salts, metal corrosion inhibitors such as sodium nitrite, sodium benzoate and the like. Preservatives such as 2,6-di-t-butylhydroxytoluene may be included.

The method of preparing the heat storage material composition of the present invention is not particularly limited, and various known mixing methods can be adopted, and the components (A), (B), (C) and, if necessary, other components can be used. It suffices to mix the additives described in 1 above and mix them uniformly. As an example, a method of heating the heat storage material composition to 40 to 50 ° C. and stirring and mixing the same can be mentioned.

Examples of the method of using the heat storage material composition of the present invention include a capsule type for filling the heat storage material composition with the heat storage material and a shell-and-tube type which does not require the heat storage material. The capsule type is obtained by injecting the heat storage material composition into a heat storage container such as a capsule and sealing the heat storage container. Examples of the material of the capsule include metals such as iron and aluminum, and plastics such as high-density polyethylene, polypropylene and polycarbonate, and high-density polyethylene is preferable. The shape of the capsule is not particularly limited, and examples thereof include a spherical shape, a plate shape, a pipe shape, a constricted cylinder shape, a twin spherical shape, and a corrugated plate shape, and are appropriately selected depending on the application. The shell-and-tube type is a method in which the shell side is filled with the heat storage material composition of the present invention, and a heat medium such as water or an antifreeze solution is flowed through the tube side to freeze the heat storage material around the tube.

[0021]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. Example 1 Trimethylolethane (reagent manufactured by Tokyo Chemical Industry Co., Ltd.) 44
g, pure water 36 g, and sulfosalicylic acid dihydrate (reagent manufactured by Wako Pure Chemical Industries, Ltd.) 20 g were mixed with stirring at 40 ° C. The obtained colorless transparent uniform solution heat storage material composition was cooled with a differential scanning calorimeter (DSC210 manufactured by Seiko Denshi Kogyo Co., Ltd.) at 10 ° C./min to −50 ° C., and at 2 ° C./min 40.
The latent heat of fusion and the melting peak temperature when the temperature was raised to ℃ were measured. As a result, the melting point was 19.9 ° C and the latent heat of fusion was 1
It was 00 J / g.

Example 2 Trimethylolethane (reagent manufactured by Tokyo Chemical Industry Co., Ltd.) 38.
5 g, pure water 31.5 g and sulfolane (reagent manufactured by Wako Pure Chemical Industries, Ltd.) 30 g were mixed with stirring at 40 ° C. The obtained colorless transparent uniform solution heat storage material composition was analyzed by a differential scanning calorimeter (DSC210 manufactured by Seiko Instruments Inc.) at 10 ° C /
The temperature was lowered to −50 ° C. in minutes, and the latent heat of fusion and melting peak temperature were measured when the temperature was raised to 40 ° C. at 2 ° C./min. As a result, melting point 20.0 ° C, latent heat of fusion 120 J / g
Met.

Example 3 Trimethylolethane (reagent manufactured by Tokyo Chemical Industry Co., Ltd.) 44
g, pure water 36 g, and sodium saccharin (reagent manufactured by Wako Pure Chemical Industries, Ltd.) 20 g were mixed with stirring at 40 ° C. The obtained colorless transparent uniform solution heat storage material composition was subjected to a differential scanning calorimeter (DSC210 manufactured by Seiko Denshi Kogyo KK) at 10 ° C.
The temperature was lowered to −50 ° C./min, and the latent heat of fusion and melting peak temperature were measured when the temperature was raised to 40 ° C. at 2 ° C./min. As a result, melting point 22.6 ° C, latent heat of fusion 140 J / g
Met.

Example 4 A colorless transparent uniform solution heat storage material composition obtained in Example 1 was filled in a polyethylene spherical capsule having an inner diameter of 64 mm, and solidification and melting at 10 ° C. to 30 ° C. were repeated in a constant temperature water bath. When it was carried out 50 times, no change was observed in the heat storage and heat release characteristics at the 1st and 50th times, and the solution after the test was a uniform transparent solution. This result shows that the heat storage material composition of the present invention is a stable heat storage material having no problem of phase separation. The melting start temperature was constant at 19 ° C. Comparative Example 1 The procedure of Example 1 was repeated except that sulfosalicylic acid dihydrate was omitted. As a result, the melting point was 29.7 ° C. and the latent heat of fusion was 180 J / g.

[0025]

EFFECTS OF THE INVENTION The heat storage material composition of the present invention has a temperature
Since it has a phase transition point at -25 ° C, has a large heat storage density, and is excellent in repeated stability without phase separation, it can be suitably used as a passive heat storage material or a cold storage material in the field of building materials and the like.

Claims (5)

[Claims] 1. A heat storage material composition comprising three components: (A) trimethylolethane, (B) water, and (C) a compound having a sulfonyl group in the molecule. 2. The component (C) is sodium saccharin,
The heat storage material composition according to claim 1, which is sulfosalicylic acid or sulfolane. 3. Component (A) 20 to 80% by weight, component (B) 19 to 50% by weight, and component (C) 1 to 50.
The heat storage material composition according to claim 1 or 2, wherein the heat storage material composition is wt%. 4. A weight ratio of the component (A) and the component (B) (A
/ B) is 75 / 25-50 / 50, The heat storage material composition in any one of Claims 1-3 characterized by the above-mentioned. 5. The phase transition point showing the maximum latent heat amount is 5 to 25 ° C.
The heat storage material composition according to any one of claims 1 to 4, wherein