JP3473283B2 - Heat storage material composition - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a heat storage material composition containing erythritol as a main component and utilizing its latent heat of fusion.

[0002]

2. Description of the Related Art Latent heat storage materials have been put into practical use by taking advantage of the fact that the heat extraction temperature is stable because they have a higher heat storage density and a constant phase change temperature than sensible heat storage materials. . Known latent heat storage materials include ice, sodium sulfate decahydrate, calcium chloride hexahydrate, sodium acetate trihydrate, and the like. However, the phase change temperature of these latent heat storage materials is relatively low, and a high phase change temperature of about 90 to 190 ° C. is desired, as a heat storage material for utilizing waste heat of hot water or boiler and utilizing solar energy. Is inappropriate.

Therefore, it has been proposed to use sugar alcohols such as erythritol, mannitol and galactitol as a heat storage material composition having a high phase change temperature (Japanese Patent Laid-Open No. 5-32963, Japanese Patent Publication No. 63-500).
946 publication). It has also been reported that erythritol is blended with pentaerythritol, pentaglycerin and neopentyl glycol having a solid phase transition point to change the phase change temperature of these two-component systems. (16th
Japan Thermophysical Properties Symposium, 1995, P221)

[0004]

Erythritol has a large heat storage amount, excellent thermal stability, and is nontoxic, but the phase change temperature is constant due to the substance. Therefore, in order to use sugar alcohol as a heat storage material, it is required to adjust the phase change temperature so as to be suitable for the heat storage system. At the 16th Symposium on Thermophysical Properties (1995, P221), it was reported that the addition of pentaerythritol, pentaglycerin and neopentyl glycol to erythritol lowered the phase change temperature of erythritol to around 100 ° C. However, there are many problems to be solved, such as the double peak of coexistence of two phases and the reduction of the amount of heat storage to less than half.

[0005]

Means for Solving the Problems As a result of intensive studies in view of the above problems, the present inventors have found that when erythritol is added with one or more selected from ethylene glycol, sodium chloride and potassium chloride as a melting point adjusting agent, the melting point of erythritol is increased. The present invention has been achieved by finding that the temperature decreases to 95 to 110 ° C.

That is, the gist of the present invention resides in a heat storage material composition comprising erythritol as a melting point adjusting agent and at least one selected from ethylene glycol, sodium chloride and potassium chloride.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, one or more selected from ethylene glycol, sodium chloride and potassium chloride as a melting point adjusting agent is added to erythritol as a main component. The content of the melting point adjusting agent is
It is usually 1 to 30% by weight, preferably 3 to 20% by weight. When the content of the melting point adjusting agent is more than 30% by weight, the content of sugar alcohol in the heat storage material composition is reduced and the heat storage amount is small, while when it is less than 1% by weight, the effect of lowering the melting point is obtained. I can't get it.

The heat storage material composition of the present invention may be used in combination with a known heat storage material such as paraffin, polyethylene glycol, polyvinyl alcohol, polyethylene and crosslinked polyethylene. Also, calcium carbonate, calcium phosphate,
Inorganic salts of calcium sulfate, calcium pyrophosphate, aluminum phosphate, silver phosphate, silver sulfate, silver chloride or silver iodide and organic salts of long-chain fatty acids such as calcium stearate, magnesium stearate, barium stearate or calcium palmitate. Supercooling inhibitors such as water-insoluble water-absorbent resins, carboxymethyl cellulose, sodium alginate, potassium alginate, thickeners such as finely divided silica, antioxidants such as phenols, amines, hydroxyamines, chromates, polyphosphorus Additives such as acid corrosion inhibitors and metal corrosion inhibitors such as sodium nitrite may be contained.

The heat storage material composition of the present invention has a melting temperature of usually 95 to 110 ° C. and a latent heat of fusion of usually 45 cal /.
g or more. The method for preparing the heat storage material composition of the present invention is not particularly limited, but erythritol, a melting point adjusting agent, and if necessary, an additive and a known heat storage material may be mixed and uniformly dispersed. In order to disperse more uniformly, a method of heating erythritol to a temperature equal to or higher than its melting point and adding and mixing a melting point adjusting agent and an additive while stirring is mentioned.

Examples of the method of using the heat storage material composition of the present invention include a capsule type in which a heat storage container is filled with the heat storage material composition and a microcapsule type in which the heat storage container is not required. 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. The material of the capsule may be any material that does not deform or melt within the operating temperature range, and examples thereof include metals such as stainless steel and aluminum, glass, and engineering plastics such as polycarbonate. 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 microcapsule type is a particle of fine heat storage material or an aggregate thereof, which is covered with a film such as a resin that does not melt or deteriorate in the operating temperature range, and has a very large surface area compared to the capsule type.
It has the advantage of high heat transfer efficiency.

In the heat storage system, the heat medium flows around the capsules and the microcapsules, and the resin coating the capsules and the microcapsules serves as a heat exchanger to store and radiate heat. Examples of the heat medium include gases such as water, steam and air.

[0012]

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. Erythritol is manufactured by Nikken Chemical Co., Ltd., ethylene glycol, potassium chloride,
Polyethylene glycol used was a reagent manufactured by Wako Pure Chemical Industries, Ltd., sodium chloride used was a reagent manufactured by Manac Co., Ltd., sodium bromide, and sodium acetate were reagents manufactured by Kishida Chemical Co., Ltd.

Example 1 4.875 g of erythritol and 0.12 of sodium chloride
5 g (2.5% by weight with respect to erythritol) were mixed in a mortar at room temperature until homogeneous. Using a sealed cell of aluminum for the melting temperature and the latent heat of fusion of the obtained heat storage material composition, a differential scanning calorimeter (manufactured by Seiko Electronics Co., Ltd.,
It was measured by DSC-220C). The results are shown in Table-1. Examples 2 to 6 The same procedure as in Example 1 was carried out except that the ratios of erythritol and sodium chloride shown in Table 1 were used. The melting temperature and the latent heat of melting are shown in Table-1. Examples 7 to 9 The same procedure as in Example 1 was carried out except that the ratios of erythritol and ethylene glycol shown in Table 1 were used. The melting temperature and the latent heat of melting are shown in Table-1.

Examples 10 to 12 The same procedure as in Example 1 was carried out except that the ratios of erythritol and potassium chloride shown in Table 1 were used. The melting temperature and the latent heat of melting are shown in Table-1. Comparative Examples 1 to 3 The procedure of Example 1 was repeated except that the ratios of erythritol and polyethylene glycol shown in Table 1 were used. The melting temperature and the latent heat of melting are shown in Table-1. Comparative Examples 4 and 5 The same procedure as in Example 1 was carried out except that the ratios of erythritol and sodium bromide shown in Table 1 were used. The melting temperature and the latent heat of melting are shown in Table-1. Comparative Examples 6 and 7 The procedure of Example 1 was repeated, except that the ratios of erythritol and sodium acetate shown in Table 1 were used. The melting temperature and the latent heat of melting are shown in Table-1.

[0015]

[Table 1] *: The melting points appeared at two places, so the latent heat of fusion at each melting point could not be measured.

[0016]

According to the present invention, without phase separation,
Further, the melting point of the heat storage material composition containing erythritol as a main component can be adjusted without lowering the heat storage amount.

Continuation of the front page (56) Reference JP-A-5-32963 (JP, A) JP-A-63-218786 (JP, A) JP-A-61-238882 (JP, A) JP-A-1-223190 (JP , A) Actual Kaihei 5-5115 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09K 5/06

Claims (3)

(57) [Claims] 1. Ethylene glycol as a melting point adjusting agent,
A heat storage material composition containing erythritol as a main component, which comprises at least one selected from sodium chloride and potassium chloride. 2. The heat storage material composition according to claim 1, wherein the blending amount of the melting point adjusting agent is 1 to 30% by weight. 3. The heat storage material composition according to claim 1, which has a melting point of 95 to 110 ° C.