JP2000129251A - Heat storage material composition and heat storage device using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide heat storage material compositions which have a phase transition temperature of 0-20 deg.C and simultaneously do not cause supercooling, and provide heat storage devices using the same. SOLUTION: This heat storage material composition comprises (A) trimethylolethane, (B) where, (C) urea, and (D) a di- or trivalent metal salt of a higher fatty acid and/or a nonionic surface active agent. A heat storage device is to effect heat exchange through a heat conductive wall between the heat storage material composition and a heat transfer medium. As the component (D), a metal salt such as calcium, zinc, iron or the like of lauric acid, palmitic acid or the like, a glycerin fatty acid ester having an HLB of not more than 10, a sorbitan monoester and the like can be illustrated. As the heat exchange system of the heat storage device, a shell type, a molded type and a capsule type can be illustrated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a heat storage material composition and a heat storage device using the same. More specifically, the present invention relates to an improvement in a trimethylolethane-water-urea-based latent heat storage material composition utilizing phase transition latent heat and a heat storage device using the heat storage material. The heat storage material composition of the present invention is useful as a heat storage material for cooling and a passive heat storage material for houses.

[0002]

2. Description of the Related Art Latent heat storage materials have been put to practical use taking advantage of the advantages of a higher heat storage density and a constant phase change temperature than sensible heat storage materials. It is used for various applications depending on the temperature range in order to utilize the transfer of latent heat accompanying the repetition of melting and solidification. As the latent heat storage material, ice, sodium sulfate decahydrate, calcium chloride hexahydrate, sodium acetate trihydrate and the like are known. These are used for cooling equipment, floor heating and the like in order to utilize latent heat at a relatively low temperature.
However, hydrated salt heat storage material once melts above its melting point, and once cooled and solidified, it cannot be completely melted even if the melting operation is performed again. There was a problem that invited. Furthermore, hydrated salt heat storage materials do not solidify even below the melting point,
A so-called supercooling phenomenon occurs. For this reason, measures for adding various additives have been made for the purpose of suppressing supercooling.

On the other hand, as an organic hydrate having a large latent heat of fusion in a relatively low temperature range, trimethylolethane hydrate (melting point: 21 to 35 ° C., latent heat of fusion: 185 kJ / Kg) is disclosed in Japanese Patent No. 2581708, Laugt. M. , Powd
er Diffr. , 6 (4), 190-193 (19
91). However, in the case of passively storing household waste heat, which is generally low grade, 15 to 2
A heat storage material having a phase transition temperature at 0 ° C. is desirable, and no effective heat storage material having a phase transition temperature in such a temperature zone and causing no phase separation phenomenon has been reported. Recently, the present inventors have proposed a ternary system composed of trimethylolethane-water-urea as a heat storage material whose melting point can be controlled at 0 to 20 ° C (Japanese Patent Application No. 9-281514).

[0004]

However, this heat storage material can completely melt-solidify without causing the phase separation phenomenon seen in general inorganic hydrated salts, and it can be used as a heat storage material alone. Although it can be used as a material, it also has a supercooling phenomenon, and it has been found that it is necessary to prevent this in order to function more effectively as a heat storage material. An object of the present invention is to provide a heat storage material composition having a phase transition temperature of 0 to 20 ° C. and not causing supercooling, and a heat storage device using the same.

[0005]

Means for Solving the Problems The present inventors have made intensive studies in view of the above circumstances, and as a result, have found that trimethylolethane-water-
It has been found that supercooling of the heat storage material can be effectively prevented by adding a metal salt of a higher fatty acid and / or a nonionic surfactant to a composition composed of urea, and the present invention has been completed.

That is, the gist of the present invention is as follows. (A) trimethylolethane, (B) water, (C) urea and (D) divalent or trivalent metal salts of higher fatty acids and / or
Or a heat storage material composition comprising a nonionic surfactant. A heat storage device configured to exchange heat between the heat storage material composition and the heat medium through a heat transfer wall according to the item 2.1.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As the divalent or trivalent metal salt of a higher fatty acid used as the component (D) of the heat storage material composition of the present invention, a higher fatty acid having 12 to 30 carbon atoms, preferably 12 to 22 carbon atoms, is used. Preference is given to salts of at least one of the divalent or trivalent metals of groups IIA, IIIB and VIII of the periodic table. As such higher fatty acids, saturated fatty acids are preferable, and specific examples thereof include, for example, lauric acid, myristic acid, palmitic acid, daturic acid, stearic acid, arachiic acid, behenic acid, lignoceric acid, serotinic acid, montanic acid, and melysin. Acid, triacontanic acid and the like. Of these, lauric acid, palmitic acid, stearic acid and behenic acid are preferred, and stearic acid and behenic acid are particularly preferred.

In the periodic table, IIA, IIIB and VIII
Of the Group II and divalent or trivalent metals, calcium, barium, zinc, iron and magnesium are preferred, and calcium is particularly preferred. Accordingly, preferred divalent or trivalent metal salts of higher fatty acids are at least one fatty acid of calcium, barium, zinc, iron and magnesium of at least one of lauric acid, palmitic acid, stearic acid and behenic acid. It is a metal salt. Particularly preferred divalent or trivalent metal salts of higher fatty acids are calcium metal salts of at least one fatty acid among stearic acid and behenic acid. Among them, calcium stearate is preferably used as one which is easily available and has an effect of preventing supercooling. These metal salts may be used alone or in combination.

The nonionic surfactant used as the other component (D) preferably has an HLB value of 10 or less, particularly preferably 5 or less.
Specific examples of such nonionic surfactants include, for example, glycerin fatty acid monoesters such as cetyl alcohol, monolaurin, monopalmitin and monostearin, glycerin fatty acid diesters such as dilaurin, dipalmitin and distearin, trilaurin and trilaurin. Glycerin fatty acid triesters such as palmitin and tristearin, sorbitan lauric acid monoester, sorbitan palmitic acid monoester, sorbitan stearic acid monoester, sorbitan fatty acid monoesters such as sorbitan oleic acid monoester, and sorbitan oleic acid triester Sorbitan fatty acid monoester ethylene oxide such as sorbitan fatty acid triester, sorbitan stearic acid monoester ethylene oxide 4 mol adduct Adducts, polyethylene glycol (200) lauric acid monoester, polyethylene glycol (200) stearic acid monoester, polyethylene glycol (200) oleic acid monoester, etc., polyethylene glycol fatty acid monoester, polyethylene glycol (200) lauric acid diester Polyethylene glycol (400) lauric acid diester, polyethylene glycol (200) stearic acid diester, polyethylene glycol (400) stearic acid diester, polyethylene glycol (20
0) Oleic acid diester, polyethylene glycol (400) Polyethylene glycol fatty acid diester such as oleic acid diester, higher alcohol ethylene oxide adduct such as oleyl alcohol ethylene oxide 2 mol adduct, Macko alcohol ethylene oxide 5 mol adduct, nonylphenol ethylene oxide 4 mol Alkylphenol ethylene oxide adducts such as adducts and the like can be mentioned.

Among them, glycerin monofatty acid ester, glycerin fatty acid diester, glycerin fatty acid triester, sorbitan fatty acid monoester, sorbitan fatty acid monoester ethylene oxide adduct, polyethylene glycol fatty acid monoester, polyethylene glycol fatty acid diester, higher alcohol ethylene ethylene oxide addition Glycerin monofatty acid ester, sorbitan fatty acid monoester, and polyethylene glycol fatty acid diester are particularly preferable. In the above compounds, the numbers in parentheses indicate the molecular weight. These may be used alone or in combination of two or more. Further, by combining a nonionic surfactant having a high HLB value and a nonionic surfactant having a low HLB value, the HLB value can be reduced to 10 or more.
The following adjustments may be used. The HLB value of the nonionic surfactant is generally 10 or less, but it is necessary that the nonionic surfactant does not largely dissolve in water. this is,
When the HLB value is larger than this, the nonionic surfactant itself dissolves in the component (B), and the hydrate formed by the trimethylolethane as the component (A) and the water as the component (B) This is because the amount becomes small and the amount of stored heat is reduced. Furthermore, the dissolution of the nonionic surfactant in component (B) conversely causes an increase in supercooling. The content of these divalent or trivalent higher fatty acid metal salts and / or nonionic surfactants is 100 parts by weight of a composition comprising trimethylolethane-water-urea having a melting point adjusted to a range of 0 to 20 ° C. Is usually 0.01 to 30 parts by weight, preferably 0.3 to 10 parts by weight, more preferably 0.3 to 5 parts by weight. When the content of the divalent or trivalent higher fatty acid metal salt and / or the nonionic surfactant is more than 30 parts by weight, the content of the trimethylolethane-water-urea as the heat storage material composition decreases. To reduce the amount of heat stored,
If the amount is less than 01 parts by weight, the effect of preventing supercooling is small.

The heat storage material composition of the present invention is not particularly limited, but usually 20 to 80% by weight of (A) trimethylolethane and 19 to 50% by weight of component (B) water.
% By weight and 1 to 50% by weight of urea of component (C), preferably 30 to 70% by weight of component (A), 20 to 40% by weight of component (B), and 5-40
% By weight. In the above, when the content of trimethylolethane of the component (A) is less than 20% by weight, the absolute amount of trimethylolethane as a hydrate in the composition decreases, and the heat storage density decreases. If the amount is more than 10% by weight, the precipitation amount of trimethylolethane which has reached the saturation solubility or more increases, and the heat storage amount decreases. Also, component (B)
If the amount of water is less than 19% by weight, the absolute amount of trimethylolethane as a hydrate decreases, and the heat storage density decreases. Conversely, if the amount exceeds 50% by weight, trimethylolethane hydrate formed Part or all of it is dissolved in excess water, and the amount of heat stored due to hydrate formation decreases. Furthermore, when the urea content of the component (C) is less than 1% by weight, the effect of adjusting the phase transition of trimethylolethane hydrate is reduced, and conversely, 50%.
If the content exceeds 5% by weight, the absolute amount of trimethylolethane hydrate formed will decrease, and the heat storage density will decrease. The weight ratio (A / B) between the component (A) and the component (B) is as follows:
Preferably it is in the range of 75/25 to 50/50. 75
If it exceeds / 25, the amount of the component (A) that cannot be a hydrate increases, so that the heat storage density decreases. On the other hand, 50/50
If it is less than 1, part or all of the produced hydrate of (A) will be dissolved in excess water, and the amount of heat storage due to hydrate formation will decrease.

[0012] The heat storage material composition of the present invention further includes a general composition other than a divalent or trivalent higher fatty acid metal salt and / or a nonionic surfactant comprising a composition comprising trimethylolethane-water-urea. As a cooling inhibitor, an inorganic salt or a hydrated inorganic salt such as sodium carbonate, sodium carbonate-water salt, sodium pyrophosphate, sodium pyrophosphate decahydrate, and tribasic calcium phosphate may be added. Further, the heat storage material composition of the present invention, if necessary, sodium polyacrylate, polyacrylamide, polyglycerin, carboxymethylcellulose, hydroxyethylcellulose, polyvinyl alcohol, sodium alginate, potassium alginate, fine silica, synthetic mica, xanthan gum, Thickeners such as carrageenan, gelatin, agar, phenol-based, amine-based, hydroxylamine-based, sulfur-based, and phosphorus-based antioxidants, and metal corrosion inhibitors such as chromate, polyphosphate, and sodium nitrite May be appropriately added. In addition, the compounding quantity of a thickener is (A) of a heat storage material composition-
It is usually 0.1 to 5 parts by weight based on 100 parts by weight of the total amount of the main components of (C).

The method of preparing the heat storage material composition of the present invention is not particularly limited, and various known mixing methods can be employed. The composition comprising trimethylolethane-water-urea can be added to a divalent or trivalent composition. The higher fatty acid metal salt and / or the nonionic surfactant may be uniformly mixed. For example, there is a method in which a composition comprising trimethylolethane-water-urea and a metal salt of a divalent or trivalent higher fatty acid and / or a nonionic surfactant are heated to 40 to 50 ° C. and stirred and mixed. Examples of the method of using the heat storage material composition of the present invention include a capsule type in which the heat storage container is filled with the heat storage material composition, and a shell and tube type in which the heat storage container is not used. 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 includes, for example, a sphere, a plate, a pipe, a constricted cylinder, a twin sphere, a corrugated plate, and the like, and is appropriately selected depending on the application. The shell & tube type is a method in which the heat storage material composition of the present invention is filled in the shell side, and a heat medium such as water or antifreeze is flowed through the tube side to freeze the heat storage material around the tube.

Hereinafter, a heat storage device of the present invention will be described with reference to the drawings. FIG. 1 is a flowchart showing an example of the heat storage device of the present invention. In FIG. 1, a heat storage device 1 has a heat storage tank 2 that stores a heat storage material and performs heat exchange via a heat transfer wall. The type of the heat storage tank 2 is not particularly limited, but a capsule type or a shell and tube type is suitable. As shown in FIG. 2, the capsule-type heat storage tank 2 partitions the inside of a drum 5 having a heat medium outlet 3a and another outlet 3b with perforated plates 6a and 6b, and is defined by perforated plates 6a and 6b. The inside of the heat storage chamber 7 is randomly filled with capsules 8 made of a heat transfer wall material, and the capsule 8 contains a heat storage material.

Therefore, when the heat medium is supplied from the heat medium outlet 3a, the heat medium passes through the perforated plate 6a, enters the heat storage chamber 7, and passes through the gap between the capsules 8,8. During this time, heat exchange is performed between the heat medium and the heat storage material, and the heat storage material absorbs heat energy and stores or radiates heat. The heat medium subjected to the heat exchange is supplied to another mechanism via the perforated plate 6b and the other heat medium inlet / outlet pipe 3b. As shown in FIG. 3, the shell & tube type has a tank body 10,
A main pipe 11 extends from the outlet 3a of the heat medium, and a large number of branch pipes 12, 12 are connected to the main pipe 11, and the other ends of the branch pipes 12, 12 are connected to a main pipe 13 on the other outlet side. The other heat medium outlet 3b is configured to be fed to another mechanism. The main pipes 11 and 13 and the branch pipes 12 and 12 are formed of a heat transfer wall material, and the heat storage material outside the main pipes 11 and 13 and the branch pipes 12 and 12 is filled with a heat storage material. The heat storage tank 2 and the heat source device 15 are provided with valve bodies 16, 17, 1
A loop is formed via the pump 8 and the pump 19. By driving the pump 19, heat energy taken in by the heat source device 15 can be stored in the heat storage tank 2.

The heat storage device 1 has a heat exchanger 20,
It is configured to exchange heat with the heat medium introduced from the heat medium passage 21. The heat exchanger 20 and the heat storage tank 2
7, a loop is formed through the three-way valve 22, the pump 23, and the valve element 18. By driving the pump 23, the heat medium exchanged in the heat storage tank 2 is transferred to the heat exchanger 2.
0 and heat exchange with the heat medium introduced from 21. The three-way valve 22 is connected to the heat medium sent from the heat storage tank 2 and the heat exchanger 20 through the bypass pipe 24.
A valve for adjusting the mixing ratio with the heat medium returning from the heat exchanger, and is used for adjusting the temperature of the heat exchanger 20.

[0017]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited to the following Examples without departing from the scope of the invention. Example 1 Trimethylolethane (reagent manufactured by Tokyo Chemical Industry Co., Ltd.) 200
g, pure water 143 g, urea (Kishida Chemical reagent) 157 g
Was stirred and mixed at 40 ° C., and 50 g of the homogenized solution was poured into a 50 ml sample bottle. Further, 1.5 g of calcium stearate (reagent made by Wako Pure Chemical Industries) was stirred and mixed as Component D. Cover the top of the container, attach a thermocouple about 1 cm from the bottom of the sample bottle, with the tip at the center of the container, hold the minimum temperature of 5 ° C for 10 hours, and maintain the maximum temperature of 20 ° C for 6 hours.
The coagulation and melting operation was performed in a thermostat capable of repeating the time keeping, and at the same time, the thermocouple temperature was monitored.
At this time, the temperature was changed from the melting state to the cooling state, and the temperature at which the supercooling was broken was observed as the crystallization temperature, and the crystallization temperature at the 5th and 20th repetitions was used as a measure of the supercooling prevention effect. The thermocouple used was a T-type thermocouple (JIS 0.7
Class 5 material SUS316, φ1.6 mm) was used.
Table 1 shows the results.

Examples 2 and 3 Instead of calcium stearate of Example 1, iron stearate (Example 2) and glycerin fatty acid ester (manufactured by Kao Corporation, trade names: Exel T, HLB:
3.8) (Example 3) The same operation as in Example 1 was performed except that (Example 3) was used. Comparative Example 1 The same evaluation as in Example 1 was performed except that calcium stearate was not added. Table 2 shows the results
Shown in Comparative Example 2 The same evaluation as in Example 1 was performed except that sodium stearate was used in place of calcium stearate. Table 2 shows the results. Comparative Example 3 The same evaluation as in Example 1 was performed, except that polyethylene glycol (600) stearic acid monoester (HLB: 13.8) was used instead of calcium stearate. Table 2 shows the results.

[0019]

[Table 1]

[0020]

[Table 2]

[0021]

According to the present invention, a composition comprising (A) trimethylolethane- (B) water- (C) urea is added to a metal salt of a divalent or trivalent higher fatty acid and / or a nonionic surfactant. The crystallization of the heat storage material is promoted by adding the agent,
It can be used effectively and efficiently as a heat storage material.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an example of a heat storage device of the present invention.

FIG. 2 is a longitudinal sectional view showing an example of a capsule-type heat storage tank.

FIG. 3 is a longitudinal sectional view showing an example of a shell and tube type heat storage tank.

[Explanation of symbols]

 Reference Signs List 1 heat storage device 2 heat storage tank 8 heat transfer wall 15 heat source device 19, 23 pump 16, 17, 18, 23 valve element 20 heat exchanger 22 three-way valve

Claims (14)

[Claims] (A) Trimethylolethane, (B)
A heat storage material composition comprising water, a divalent or trivalent metal salt of (C) urea and (D) a higher fatty acid, and / or a nonionic surfactant. 2. The heat storage material composition according to claim 1, wherein the higher fatty acid is a fatty acid having 12 to 30 carbon atoms. 3. The heat storage material composition according to claim 1, wherein the higher fatty acid is at least one of lauric acid, palmitic acid, stearic acid, and behenic acid. 4. The method according to claim 1, wherein the metal of the metal salt is a metal of the periodic table
The heat storage material composition according to any one of claims 1 to 3, which is at least one of groups B and VIII. 5. The heat storage material composition according to claim 1, wherein the metal of the metal salt is at least one of calcium, barium, zinc, iron and magnesium. 6. The heat storage material composition according to claim 1, wherein the nonionic surfactant has an HLB of 10 or less. 7. A non-ionic surfactant having an HLB of 10 or less, glycerin monofatty acid ester, glycerin fatty acid diester, glycerin fatty acid triester, sorbitan fatty acid monoester, sorbitan fatty acid monoester ethylene oxide adduct, polyethylene glycol fatty acid monoester, The heat storage material composition according to any one of claims 1 to 6, wherein the heat storage material composition is at least one selected from polyethylene glycol fatty acid diesters, higher alcohol ethylene oxide adducts, and alkylphenol ethylene oxide adducts. 8. The blending amount of the component (D) is:
The heat storage material composition according to any one of claims 1 to 7, wherein the amount is 0.01 to 30 parts by weight based on 100 parts by weight of the total of the component (B) and the component (C). 9. The heat storage material according to claim 1, wherein the component (A) is 20 to 80% by weight, the component (B) is 19 to 50% by weight, and the component (C) is 1 to 50% by weight. Composition. 10. A / B (weight ratio) of 75/25 to 50
The heat storage material composition according to any one of claims 1 to 9, wherein the ratio is / 50. 11. The method according to claim 1, wherein the phase transition point is 0 to 20 ° C.
11. The heat storage material composition according to any one of items 1 to 10. 12. A heat storage device configured to exchange heat between the heat storage material composition according to claim 1 and a heat medium via a heat transfer wall. 13. The heat storage device according to claim 12, wherein the heat exchange system is a shell and tube type, wherein the heat storage material composition is stored in the shell portion, and the heat medium flows through the tube. 14. The heat storage device according to claim 12, wherein the heat exchange method is a capsule type, wherein the heat storage material composition is stored in a synthetic resin capsule, and a heat medium is brought into contact with the capsule.