JP2007106947A - Method for manufacturing heat storage material composition and heat storage material composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide such a method for manufacturing a heat storage material composition as needs only a little consumption of the heat energy when manufacturing the heat storage material composition and as is excellent in the safety when manufacturing thereof owing to no need for a high-temperature operation. <P>SOLUTION: The method for manufacturing a heat storage material composition that contains sodium acetate trihydrate and trisodium phosphate, comprises mixing the trisodium phosphate which contains a trisodium phosphate dehydrate obtained by so dry-dehydrating trisodium phosphate dodecahydrate as for a percentage of weight loss to be 30% by weight or more, with sodium acetate trihydrate in such a way that 100 moles of the above sodium acetate trihydrate have a content of trisodium phosphate of 2.5 moles or more in terms of the anhydride. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a latent heat storage material composition used for heating a building or the like, and a heat storage material composition obtained by the method.

  Many proposals have been made to use a salt hydrate having a solid-liquid phase change property as a heat storage material, which has already been put into practical use in the field of floor heating and the like. Among salt hydrates, sodium acetate trihydrate has attracted attention as a heat storage material candidate because it has a melting point of 58 ° C. and a heat of fusion of about 60 cal / g.

  However, when a salt hydrate is used alone as a heat storage material, the supercooling phenomenon occurs, which has been a big barrier when used as a heat storage material. There have been many proposals for supercooling inhibitors to overcome this barrier.

As a method for preventing supercooling of sodium acetate trihydrate, a method using a specific supported crystal has been proposed. Examples of supported crystals include sodium salts such as disodium hydrogen phosphate and trisodium phosphate (see Patent Document 1 and Patent Document 2).
Japanese Patent Publication No. 61-42957 Japanese Patent Publication No. 2-15598

When trisodium phosphate dodecahydrate is used as the support crystal, it is activated as a supercooling inhibitor by heating and melting together with sodium acetate trihydrate, cooling and adding seed crystals to solidify. Watanabe discloses that the heating temperature is 353 to 363 K (80 to 90 ° C.), thereby changing trisodium phosphate dodecahydrate to hemihydrate (see Non-Patent Document 1). .
Watanabe, Chemical Engineering Papers, Vol. 17, pp. 48-53, 1991

  However, when trisodium phosphate is used as a supercooling preventive agent in a heat storage material composition mainly composed of sodium acetate trihydrate, 80 mg of sodium acetate trihydrate and trisodium phosphate 12 hydrate are used. Since it is necessary to heat and melt at a high temperature of ˜90 ° C., there are problems such as high heat energy consumption during production and unfavorable safety because of high temperature operation.

As a result of intensive studies to solve the above-mentioned problems, the present inventors use a dry dehydrated trisodium phosphate dodecahydrate dehydrated in advance as at least part of the trisodium phosphate dodecahydrate. Thus, the present inventors have found that the heating temperature can be lowered to about 60 to 65 ° C. and completed the present invention.
That is, the present invention relates to a method for producing a heat storage material composition containing sodium acetate trihydrate and trisodium phosphate, and dry dehydration so that the weight loss rate of trisodium phosphate 12 hydrate is 30% by weight or more. Trisodium phosphate containing trisodium phosphate dehydrate and sodium acetate trihydrate obtained in the above manner, the content of trisodium phosphate per 100 mol of sodium acetate trihydrate is 2 in terms of anhydrous. It is the manufacturing method of the heat storage material composition mixed so that it may become 0.5 mol or more. Moreover, this invention is a thermal storage material composition obtained by the said manufacturing method.

According to the method for producing a heat storage material composition of the present invention, the heat storage material composition can be obtained by low-temperature heating of 60 to 65 ° C. Therefore, the amount of heat energy consumed during the production of the heat storage material composition can be reduced, and since no high-temperature operation is required, the production safety is excellent.

In the present invention, trisodium phosphate containing trisodium phosphate dehydrate obtained by dry-dehydrating trisodium phosphate dodecahydrate to a weight loss rate of 30% by weight or more is used. All of the trisodium phosphate to be used may be a trisodium phosphate dehydrate obtained by dry dehydration, a part of the trisodium phosphate dehydrate, and others are trisodium phosphate and trisodium phosphate. It may be a hydrate.
The method of dry-dehydrating trisodium phosphate 12 hydrate is not limited, and using an oven, a thermostatic bath, a heater, etc., trisodium phosphate 12 water so that the weight loss rate is 30% by weight or more. What is necessary is just to heat a Japanese thing. The weight loss rate is determined as the ratio of the weight reduced by dry dehydration to the weight of trisodium phosphate dodecahydrate before dry dehydration. When the weight loss rate is less than 30% by weight, the effect of preventing overcooling is easily lost at high temperatures.
The conditions for dry dehydration are not particularly limited, but a temperature of 55 ° C. or higher is usually required for the dehydration of trisodium phosphate dodecahydrate hydrated water. Preferably,
(A) Method of dry dehydration at 105-130 ° C (B) Method of dry dehydration at 70-85 ° C for 1 hour or more and then dry dehydration at 86-130 ° C (C) At 55-85 ° C Conditions such as a method of dry dehydration for 7 hours or more are used. From the viewpoint of the specifications of the heating device and work efficiency, a suitable one can be selected from these conditions.
The dry dehydration in the present invention is a method of dehydrating trisodium phosphate dodecahydrate by heating it in an open system under a gas such as air. In contrast, trisodium phosphate dodecahydrate is a system that does not evaporate with sodium acetate trihydrate, and is heated at 80 to 90 ° C. and then cooled and seeded to solidify. This method is called wet dehydration.

  The shape of trisodium phosphate dodecahydrate used for dry dehydration is not particularly limited. A powder form is preferable from the viewpoint of drying efficiency, but it may be a crystal form. Although it may be mixed with other materials to form granules or lumps, it is necessary to dry-dehydrate so that the weight loss rate of trisodium phosphate dodecahydrate itself is 30% by weight or more.

  The method of mixing the trisodium phosphate dehydrate obtained by dry dehydration of trisodium phosphate 12 hydrate and sodium acetate trihydrate is not particularly limited. The dehydrated state must be maintained at a weight percentage or more. Trisodium phosphate may be mixed with an aqueous solution of sodium acetate trihydrate or anhydrous sodium acetate, or may be mixed with a powder of sodium acetate trihydrate. A method of adding trisodium phosphate dehydrate to a melt obtained by heating sodium acetate trihydrate to a melting point or higher is particularly preferable from the viewpoint of efficiency. A method in which a predetermined amount of trisodium phosphate dehydrate is put in a container in advance and then a sodium acetate trihydrate melt is added is particularly preferable from the viewpoint of production efficiency.

  When an aqueous solution is used as sodium acetate trihydrate, it is used as an aqueous solution having a sodium acetate concentration of 52 to 60% by weight in terms of sodium acetate anhydride. If the amount is less than 52% by weight, the heat storage amount becomes too low, and if it exceeds 60% by weight, sodium acetate anhydride exists as an insoluble matter.

  In the method for producing a heat storage material composition of the present invention, trisodium phosphate containing trisodium phosphate dehydrate and sodium acetate trihydrate are mixed with trisodium phosphate per 100 moles of sodium acetate trihydrate. It mixes so that content may become 2.5 mol or more in anhydrous conversion. The amount of trisodium phosphate dehydrate in the heat storage material composition is preferably 0.7 to 50 mol per 100 mol of sodium acetate trihydrate.

  In the present invention, a composition obtained by adding trisodium phosphate containing trisodium phosphate dehydrate to sodium acetate trihydrate is solidified, and this is solidified with another sodium acetate trihydrate and triphosphate phosphate. A heat storage material composition may be produced by adding it as a seed crystal to a composition containing sodium. Such a method for producing a heat storage material composition is particularly preferable from the viewpoint of productivity because the amount of trisodium phosphate dodecahydrate for dry dehydration treatment can be reduced.

  In the present invention, a solid-liquid separation inhibitor may be used in combination with acetic acid trihydrate and trisodium phosphate as necessary. When the heat storage material composition is solidified, it may be separated into a trihydrate crystal and the remaining aqueous solution, and the solid-liquid separation inhibitor has an effect of preventing such a phenomenon. Examples of the solid-liquid separation inhibitor include polyacrylamide, partially hydrolyzed polyacrylamide, and carboxymethyl cellulose. The preferable addition amount of the solid-liquid separation inhibitor is usually 1 to 10% by weight with respect to the total amount of the heat storage material composition.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[Example 1]
5 g of trisodium phosphate dodecahydrate powder was placed on a porcelain dish, heated in an oven to 110 ° C. and dry dehydrated for 2 hours to obtain trisodium phosphate dehydrate. The weight loss rate by dry dehydration was 53% by weight. 0.2 g of the trisodium phosphate dehydrate was put in a polyethylene bag.
A 150 ml beaker was charged with 95.5 g of sodium acetate trihydrate and 2.9 g of water, and heated in a 62 ° C. water bath to obtain 98.4 g of an aqueous sodium acetate solution having a sodium acetate anhydride equivalent concentration of 58.5 wt%. While stirring this, 8.26 g of trisodium phosphate 12 hydrate was added and stirred for 20 minutes, and then partially hydrolyzed polyacrylamide (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumifloc FA-) as a solid-liquid separation inhibitor. 30) Add 3.61 g and stir for another 40 minutes. 10 g of the obtained liquid was put into a polyethylene bag containing the aforementioned trisodium phosphate dehydrate. When it was left at room temperature for 10 minutes, it became below the melting temperature of sodium acetate trihydrate, so several grains (0.01 g or less) of sodium acetate trihydrate crystals were used as seed crystals to obtain a heat storage material composition. It was.
When the polyethylene bag was heat-sealed and sealed, it was further sealed in an aluminum laminate bag and allowed to stand at room temperature overnight, and the whole solidified.
When this was put into an oven and heated at 80 ° C. for 7 hours and taken out, the whole was melted. When this was allowed to stand overnight at room temperature, the whole solidified again, and there was an effect of preventing overcooling even after high temperature conditions had elapsed.

[Example 2]
5 g of trisodium phosphate dodecahydrate powder was placed on a porcelain dish and preheated in an oven at 80 ° C. for 2 hours, followed by dry dehydration at 110 ° C. for 2 hours to obtain trisodium phosphate dehydrate. . The weight loss rate by dry dehydration was 53% by weight. 0.2 g of the trisodium phosphate dehydrate was put in a polyethylene bag.
Thereafter, a heat storage material composition was obtained in the same manner as in Example 1.
When the polyethylene bag was heat sealed and the heat storage material composition was sealed, it was further sealed in an aluminum laminate bag and allowed to stand at room temperature overnight, and the whole solidified.
When this was put into an oven and heated at 80 ° C. for 7 hours and taken out, the whole was melted. When this was allowed to stand overnight at room temperature, the whole solidified again, and there was an effect of preventing overcooling even after high temperature conditions had elapsed.

[Example 3]
5 g of trisodium phosphate dodecahydrate powder was placed on a porcelain dish and preheated in an oven at 80 ° C. for 2 hours, followed by dry dehydration at 90 ° C. for 6 hours to obtain trisodium phosphate dehydrate. . The weight loss rate by dry dehydration was 53% by weight. 0.2 g of the trisodium phosphate dehydrate was put in a polyethylene bag.
Thereafter, a heat storage material composition was obtained in the same manner as in Example 1.
When the polyethylene bag was heat sealed and the heat storage material composition was sealed, it was further sealed in an aluminum laminate bag and allowed to stand at room temperature overnight, and the whole solidified.
When this was put into an oven and heated at 80 ° C. for 7 hours and taken out, the whole was melted. When this was allowed to stand overnight at room temperature, the whole solidified again, and there was an effect of preventing overcooling even after high temperature conditions had elapsed.

[Example 4]
5 g of trisodium phosphate dodecahydrate powder was placed on a porcelain dish and dried in an oven at 80 ° C. for 9 hours to obtain trisodium phosphate dehydrate. The weight loss rate by dry dehydration was 34% by weight. 0.2 g of the trisodium phosphate dehydrate was put in a polyethylene bag.
Thereafter, a heat storage material composition was obtained in the same manner as in Example 1.
When the polyethylene bag was heat sealed and the heat storage material composition was sealed, it was further sealed in an aluminum laminate bag and allowed to stand at room temperature overnight, and the whole solidified.
When this was put into an oven and heated at 80 ° C. for 7 hours and taken out, the whole was melted. When this was allowed to stand overnight at room temperature, the whole solidified again, and there was an effect of preventing overcooling even after high temperature conditions had elapsed.

[Example 5]
5 g of trisodium phosphate dodecahydrate powder was placed on a porcelain dish and subjected to dry dehydration in an oven at 60 ° C. for 48 hours to obtain trisodium phosphate dehydrate. The weight loss rate by dry dehydration was 53% by weight. 0.2 g of the trisodium phosphate dehydrate was put in a polyethylene bag.
Thereafter, a heat storage material composition was obtained in the same manner as in Example 1.
When the polyethylene bag was heat sealed and the heat storage material composition was sealed, it was further sealed in an aluminum laminate bag and allowed to stand at room temperature overnight, and the whole solidified.
When this was put into an oven and heated at 80 ° C. for 7 hours and taken out, the whole was melted. When this was allowed to stand overnight at room temperature, the whole solidified again, and there was an effect of preventing overcooling even after high temperature conditions had elapsed.

[Example 6]
5 g of trisodium phosphate dodecahydrate powder was placed on a porcelain dish and subjected to dry dehydration in an oven at 80 ° C. for 15 hours to obtain trisodium phosphate dehydrate. The weight loss rate by dry dehydration was 49% by weight. 0.2 g of this was put into a polyethylene bag.
Thereafter, a heat storage material composition was obtained in the same manner as in Example 1.
When the polyethylene bag was heat sealed and the heat storage material composition was sealed, it was further sealed in an aluminum laminate bag and allowed to stand at room temperature overnight, and the whole solidified.
When this was put into an oven and heated at 80 ° C. for 7 hours and taken out, the whole was melted. When this was allowed to stand overnight at room temperature, the whole solidified again, and there was an effect of preventing overcooling even after high temperature conditions had elapsed.

[Comparative Example 1]
A heat storage material composition was obtained in the same manner as in Example 1 except that the trisodium phosphate dehydrate was not put in the polyethylene bag.
When the polyethylene bag was heat sealed and the heat storage material composition was sealed, it was further sealed in an aluminum laminate bag and allowed to stand at room temperature overnight, and the whole solidified.
When this was put into an oven and heated at 80 ° C. for 7 hours and taken out, the whole was melted. When this was left to stand at room temperature overnight, the whole remained liquid and was in a supercooled state.

[Comparative Example 2]
5 g of trisodium phosphate dodecahydrate powder was placed on a porcelain dish and dry dehydrated in an oven at 80 ° C. for 2 hours to obtain trisodium phosphate dehydrate. The weight loss rate by dry dehydration was 17.5% by weight. 0.2 g of the trisodium phosphate dehydrate was put in a polyethylene bag.
Thereafter, a heat storage material composition was obtained in the same manner as in Example 1.
When the polyethylene bag was heat sealed and the heat storage material composition was sealed, it was further sealed in an aluminum laminate bag and allowed to stand at room temperature overnight, and the whole solidified.
When this was put into an oven and heated at 80 ° C. for 7 hours and taken out, the whole was melted. When this was left to stand at room temperature overnight, the whole remained liquid and was in a supercooled state.

[Comparative Example 3]
5 g of trisodium phosphate dodecahydrate powder was placed on a porcelain dish and subjected to dry dehydration in an oven at 60 ° C. for 6 hours to obtain trisodium phosphate dehydrate. The weight loss rate by dry dehydration was 23.5% by weight. 0.2 g of the trisodium phosphate dehydrate was put in a polyethylene bag.
Thereafter, a heat storage material composition was obtained in the same manner as in Example 1.
When the polyethylene bag was heat sealed and the heat storage material composition was sealed, it was further sealed in an aluminum laminate bag and allowed to stand at room temperature overnight, and the whole solidified.
When this was put into an oven and heated at 80 ° C. for 7 hours and taken out, the whole was melted. When this was left to stand at room temperature overnight, the whole remained liquid and was in a supercooled state.

Claims (5)

  A method for producing a heat storage material composition comprising sodium acetate trihydrate and trisodium phosphate, the phosphorus obtained by dry-dehydrating trisodium phosphate dodecahydrate to a weight loss rate of 30% by weight or more Trisodium phosphate containing trisodium acid dehydrate and sodium acetate trihydrate have a trisodium phosphate content per 100 moles of sodium acetate trihydrate of 2.5 moles or more in terms of anhydrous The manufacturing method of the thermal storage material composition mixed so that it may become.   The manufacturing method of the heat storage material composition of Claim 1 using the trisodium phosphate dehydrate obtained by carrying out dry dehydration of trisodium phosphate dodecahydrate at 105-130 degreeC.   The heat storage according to claim 1, wherein trisodium phosphate dehydrate obtained by dry dehydration of trisodium phosphate dodecahydrate at 70 to 85 ° C for 1 hour or more and further dry dehydration at 86 to 130 ° C is used. Manufacturing method of material composition. The manufacturing method of the heat storage material composition of Claim 1 using the trisodium phosphate dehydrate obtained by carrying out dry dehydration of trisodium phosphate dodecahydrate at 55-85 degreeC for 7 hours or more. The thermal storage material composition obtained by the method in any one of Claims 1-4.