JPH0617044A - Cold accumulating material and preparation thereof - Google Patents

Abstract

PURPOSE:To obtain a cold accumulating material which does not become massive even after coagulation of the substance that causes phase change and is excellent in heat transfer performance and fluidity. CONSTITUTION:A cold accumulating material comprising a substance 5 that causes phase change, a substance 6 which has no compatibility with and a freezing point lower than the substance 5, and a surfactant 7 which improves the mixing condition of both the substances 5 and 6. The cold accumulating material is prepared by scraping its raw materials, i.e., the substances 5 and 6 and the surfactant 7, with a blade 10 in a closed vessel 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold storage material and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, there are many systems that use a cold storage material in the form of a slurry (sherbet). For example, Japanese Patent Laid-Open No. 1-
In No. 155135, an aqueous solution obtained by adding glycerin or the like as a solute to water (solvent) which is a phase change substance is used as a cold storage material.

[0003]

However, since the above-mentioned cold accumulating material is compatible, the solution is concentrated during the phase change and a stable solidification temperature cannot be obtained. The tendency is more remarkable as the temperature is lower. Therefore, the food transport storage box (CR
It cannot be applied to a system that requires strict temperature control such as B).

By the way, examples of the phase change substance which can obtain a stable solidification temperature include an aqueous solution of an inorganic salt and paraffin. However, these alone, of course, are mixed with a liquid that is incompatible with the phase change substance, and this liquid is interposed between the solidified particles of the solidified phase change substance to form a slurry having excellent heat transfer performance and fluidity. There is a problem that the solidified particles of the phase change substance become lumps even if an attempt is made to obtain a cold storage material.

The present invention has been made in view of the above circumstances, and improves the mixing degree of both substances by adding a surfactant to a mixture of a phase change substance and a substance incompatible with the substance. Another object of the present invention is to provide a cold storage material which does not become lumpy due to the action of the surfactant even after the solidification of the phase change material and has excellent heat transfer performance and fluidity, and a method for producing the same.

[0006]

A first aspect of the present invention provides a phase change substance, a substance which is incompatible with the phase change substance and has a lower freezing point than the phase change substance, and a mixed state of the two substances. A regenerator material characterized by comprising a surfactant for improving. A second invention of the present application comprises an airtight container, a cooling means for cooling the airtight container, a rotatable scraping blade provided in the airtight container, and a drive source for rotating the scraping blade. In a method for manufacturing a cold storage material using a manufacturing apparatus, a phase change substance, a substance that is incompatible with the phase change substance and has a lower freezing point than the phase change substance, and an interface that improves the mixed state of the two substances. Manufacture of a cold storage material in which a cold storage material containing an activator is placed in the closed container, and the phase change substance that undergoes solid phase growth on the inner wall surface of the closed container is scraped off by a scraping blade to obtain a slurry cold storage material. Is the way.

By the way, in the above surfactant, W /
In the case of an O-type emulsion (water in which oil is dispersed), there is a problem of insufficient latent heat because the supercooling is large. The present inventor has conducted various studies there, and found that such a problem of insufficient latent heat is caused by the fact that the particle size of the W / O type emulsion is small.

The particle sizes of the W / O type emulsion and the O / W type emulsion (oil dispersed in water) were measured, and as shown in FIG. Was about 3 μm. On the other hand, in the O / W type emulsion, oil forms a continuous layer because oil is scattered in the water. From this, it was confirmed that the W / O type emulsion supercooled, but the O / W type emulsion did not supercool (see FIG. 9). HLB (hydrophile-lipophile balan) with the best emulsification rate of W / O emulsion type
The value of ce: hydrophilic / lipophilic balance) varies depending on the type of oil, but is preferably within the range of the best HLB ± 1, that is, 9 to 11.
For example, when mineral oil is used, HLB = 10.

In the present invention, examples of the surfactant include polyoxyethylene alkylphenyl ether and polyoxyethylene alkyl ether among nonionic surfactants.

In the present invention, when the W / O type emulsion is cooled to make ice, it becomes a solid when it is simply cooled. Therefore, by cooling with stirring, a particulate and fluid regenerator material is manufactured. . However, there is a problem that solid-phase growth occurs on the heat transfer surface. For example, when the flat plate is pressed against the heat transfer surface by the force of the spring, it cannot be scraped off when the solid phase growth becomes large. Therefore, as the scraping blade, for example, as shown in FIGS. 7 (A) and 7 (B), a blade 22 having irregularities 42a is provided and rotated via a stay 41 fixed to the lower end of the shaft 13. Therefore, it is preferable to manufacture a cold storage material having fluidity.

In the present invention, the phase change substance A is
For example, potassium nitrate 9.7% by weight (Tf (freezing point: ° C)
= -2.8), potassium chloride 19.5% by weight (Tf =-
10.7), 22.4% by weight of sodium chloride (Tf =-
21.2), calcium nitrate 42.9% by weight (Tf =-
An aqueous solution containing an inorganic salt such as 28.7) (however, all the concentrations are eutectic concentrations) can be mentioned.

In the present invention, the substance B which is incompatible with the phase change substance and has a lower freezing point than the phase change substance is, for example, mineral oil type oil (refrigerating machine oil, torque converter oil, hydraulic oil), synthetic oil. (Silicon oil, fluorine oil).

In the present invention, the blending ratio of the phase change substance A and the substance B is preferably changed according to the required heat quantity. Since the surfactant has a low interfacial tension or the ability is almost the same even if added at a micelle limit concentration or more,
It is sufficient to add about 0.1% by weight to the total amount of the phase change substance A and the substance B.

[0014]

In the present invention, the action of the regenerator material comprising a phase change substance, a substance which is incompatible with the phase change substance and has a lower freezing point than the phase change substance, and a surfactant is as follows. is there. A description will be given by using the attached numbers in FIG. 1 described later.

(Before cold storage) The cold storage raw material 8 is in the closed container 2 in a liquid state in which the phase change material 5 and the material 6 are well mixed by the effect of improving the dispersibility of the surfactant 7. Here, the mixing ratio of the phase change substance 5, the substance 6, and the surfactant 7 is determined by the required amount of cold heat of the moving body 23 and the sub plant 25. Since the system uses mainly latent heat, the required heat quantity of the moving body 23 and the sub-plant 25 is mostly covered by the phase change material 5. b (during cold storage) When the cold storage material 8 is cooled to the freezing point of the phase change substance 5 by the cooling means 9, the phase change substance 5 solidifies and becomes solid unless a supercooling phenomenon occurs. At this time, the substance 6 has a lower freezing point than that of the phase change substance 5, and thus remains liquid. After the solidification is started, the phase change material 5 that gradually grows on the wall surface of the closed container 2 is scraped off by the scraping blade 42 and becomes fine particles, and the amount thereof is gradually increased. In this state, it becomes a slurry-like regenerator material for the first time. The fine-grained phase-change substance 5 is dispersed in the substance 6 without the particles sticking to each other due to the dispersion effect due to the presence of the surfactant 7, and is superior in the transmission performance to the lump-shaped substance and has a fluidity. It becomes a cold storage material in the form of a slurry. If the fluidity is improved, the supply to the heat exchangers in the moving body 23 and the sub plant 25 becomes easy.

(After the cold storage) All the phase change substances 5 present are completely solidified, and when the temperature becomes lower than the freezing point, the cold storage is completed, and thereafter, the cooling means cools down to the cooling temperature. At this time, the cooling temperature should be higher than the freezing point of the substance 6.

After the completion of the cold storage, the cold storage material in the form of slurry is carried and supplied by the carrying means to a moving body having no refrigerator or a sub-plant. The cold storage material that has been cooled and melted in the moving body and the sub-plant is returned to the cold storage base 21 in the case of the moving body and returned to the closed container 2 by the pipeline in the case of the sub-plant.

According to the present invention, the addition of the surfactant 7 improves the mixing degree of the phase change substance 5 and the substance 6,
Even after the phase change substance 5 is solidified, it does not become lumpy due to the action of the surfactant 7, and a cold storage material in the form of a slurry having excellent heat transfer performance and fluidity can be obtained.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

First, a manufacturing apparatus for manufacturing the regenerator material according to the present invention will be described. In FIG. 1, 1 indicates a manufacturing unit. The manufacturing unit 1 is provided with a cylindrical closed container 2 serving as a cool storage material manufacturing unit that manufactures a cool storage material. The closed container 2 is made of stainless steel, aluminum, copper, or the like. The closed container 2 is provided with a take-out port 3 and a return port 4 for the slurry regenerator material. In the closed container 2, a phase change substance 5, a substance 6 which is incompatible with the phase change substance 5 and has a freezing point lower than that of the phase change substance, and a surfactant for improving a mixed state of the both substances The regenerator material 8 composed of 7 and 7 is charged. On the outside of the closed container 2, a cooling means 9 is arranged in contact with the outer wall of the closed container 2. Inside the closed container 2, a rotatable blade (scraping blade) 42 for scraping off the solidified phase change substance 5 by exchanging heat with the cooling means 9 on the inner wall surface of the container of the closed container 2 is arranged. There is.

As shown in FIGS. 7A and 7B, the blades 42 are fixedly provided on the stay 41 fixed to the lower end of the shaft 13 connected to the motor 12. Here, the blades 42 are angled in order to improve fluidity and reduce required power. Further, the blade 42 is provided with irregularities 42a, but the left and right sides are made asymmetric so that the remaining portion is reduced when it makes one round. Further, the shaft 13 has blades 42
In order to improve the fluidity of the inside of the container, it is arranged so as not to be deeply interposed in the closed container 2. The material of the blades 42 is softer than that of the closed container 2 in consideration of wear. Specifically, if the closed container 2 is made of stainless steel, aluminum,
Resin such as polyacetal is used, and if the closed container 2 is made of aluminum or copper, resin such as polyacetal is used.

In such a manufacturing apparatus, first, heat is exchanged between the cold storage material 8 in the closed container 2 and the wall surface of the closed container 2. Here, the cold storage material raw material 8 exchanges heat with the cooling means 9 until it reaches a temperature lower than the freezing point of the phase change substance 5 and higher than the freezing point of the substance 6. In this process, since the solid phase of the phase change material 5 grows on the inner wall surface of the closed container 2 serving as the heat transfer surface, the asymmetrical unevenness 42a of the blade 42 crushes the solid phase growth of the phase change material 5, Stir and scrape at the anchor wing. Then, after the phase change substance 5 in the cold storage material 8 is completely phase-changed (solidified), the cold storage is completed to obtain a slurry-like cold storage material having fluidity.

By the way, after the cold storage is completed, the slurry-like cold storage material is taken out of the closed container 2 by the system as shown in FIG. 2 or 3. Here, FIG. 2 is a cold storage base (main implant) 21 and a joint 22 are used to receive a cold storage material provided in a moving body (for example, a CRB) 23 (which is not equipped with a refrigerator that requires cold heat). A system for connecting with the space 24 is shown. FIG. 3 shows a demand-supply integrated system in which the cold storage base 21 (supply side) and the sub-plant 25 (demand side) are connected by a pipeline.

As the constitution of the cold storage base 21, those shown in FIGS. 4 to 6 are known. FIG. 4 includes a cold storage material production / storage section 26, a refrigerator 27, and a conveying means (for example, a slurry pump) 28.
Thus, it is taken out of the closed container 2 through the take-out port 3.

FIG. 5 shows a refrigerator 27 and the manufacturing unit 1
And a storage section 30 having a cold storage means 29, and transportation means 28, 31. In this case, by stocking once in the storage unit 30, even if the cold is stored in the manufacturing unit 1, it can be supplied from the storage unit 30 to the moving body 23 or the sub-plant 25 by the conveying means 31 as needed. Is.

FIG. 6 shows a structure in which a filter 32 is provided in the storage unit 30 of FIG. The cold storage material in the form of a slurry made of the closed container 2 is sent to the storage section 30 by the transfer means 28.
At this time, if the unsolidified phase change substance 5 is present, it is necessary to return it to the closed container 2 in the manufacturing unit 1 in order to solidify it again. Therefore, in FIG. 6, the filter 32 in the reservoir 30 is
The solid-liquid is screened by, and the unsolidified phase change substance 5 and the carrier liquid substance 6 are returned. By repeating this, if the storage unit 30 can store the slurry-like cold storage material for the required amount of cold heat, it can be supplied to the moving body 23 or the sub-plant 25 by the carrying means 31.

Next, a case of manufacturing a cold storage material in the form of a slurry using the above manufacturing apparatus will be described. Here, a KCl aqueous solution (eutectic concentration: 19.5% by weight, Tf: -11.0 ° C) was used as the phase change substance 5, and a silicone oil (viscosity 10 cst, 25 ° C) was used as the substance 6 in a weight ratio. Change substance 5: substance 6 = mixed so as to be 2: 8, and sorbitan sesquioleate type surfactant (HLB = 3.
7) and polyoxyethylene sorbitan monolaurate type (HLB = 16.7) were mixed at a weight ratio of 1: 1 and a weight average was obtained, so HLB = 10.2 was obtained. 0.1 wt% was added.

That is, first, the substance 5,
6 and the surface-active agent 7 were placed in the cold storage material 8, and heat exchange was performed in the closed container 2 between the cold storage material 8 and the wall surface of the closed container 2. Here, the cold storage material raw material 8 exchanges heat with the cooling means 9 until it reaches a temperature lower than the freezing point of the phase change substance 5 and higher than the freezing point of the substance 6. In this process, since the solid phase of the phase change material 5 grows on the inner wall surface of the closed container 2 serving as the heat transfer surface, the uneven surface 42a of the blade 42 crushes the phase change material 5 and the anchor blade portion It was stirred and scraped off. Then, the phase change substance 5 in the cold storage raw material 8
After the phase change (solidification) was completed, the cold storage was completed to obtain a slurry-like cold storage material having fluidity. Next, the slurry-like regenerator material is taken out of the closed container 2 by using the conveying means 28 and 31 in the system as shown in FIG. 2 or 3.

The thus obtained slurry-like cold storage material comprises the phase change substance 5, the substance 6 which is incompatible with the phase change substance 5 and has a lower freezing point than the phase change substance, Surfactant 7 for improving the mixed state of both substances
Since it is composed of and, for example, -10 ℃, -20 ℃
When cold storage such as at a negative temperature is performed, it has fluidity in that temperature range, the solidification temperature is stable, and the heat transfer performance is excellent. On the other hand, the conventional regenerator materials have a freezing temperature of minus temperature as described above, and have no fluidity and a stable freezing temperature. The cold storage material of Japanese Patent Laid-Open No. 1-155135 has fluidity and is capable of cold storage at a negative temperature, but it is difficult to apply it to those whose temperature control is strict due to temperature change due to concentration during solidification. Further, in the prior art, a system for putting the regenerator material in and out of the moving body 23 is one which is used by solidifying-melting in a packed state.
Since it cannot be conveyed by a conveying means such as a slurry pump, it requires much labor to carry, and the heat transfer area is smaller than that of fine particles, and the heat transfer performance is inferior.

In the above embodiment, the phase change substance 5 is KCl aqueous solution, the substance 6 is silicone oil, and the surfactant is xylene nonylphenyl ether type. For example, the surfactant is polyoxyethylene nonylphenyl ether. The same applies when a mold (HLB = 10) is used. I mentioned the case of using a surfactant,
The present invention is not limited to this, and other materials described in "Means for Solving the Invention" may be used. Also, it goes without saying that the blending ratios of these are not limited to those in the above-mentioned examples. For example, phase change material (5): material (6) = 4: 6
Alternatively, also for 6: 4, good results were obtained as in the above-mentioned examples.

In the above embodiment, the materials of the closed container and the blade have been described, but the materials are not limited to those described, and other materials can be used as long as the material of the blade is softer than that of the closed container. Material may be used.

[0032]

As described above in detail, according to the present invention, the mixing degree of the phase change substance and the substance which is not compatible with this substance is improved by the addition of the surface active agent, and the surface activity is maintained even after the solidification of the phase change substance. It is possible to provide a regenerator material which does not become lumpy due to the action of the agent and has excellent heat transfer performance and fluidity, and a manufacturing method thereof.

[Brief description of drawings]

FIG. 1 is an explanatory view of an apparatus for producing a slurry regenerator material according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of how to take out the slurry-like cool storage material after the cool storage is completed to the outside of the closed container.

FIG. 3 is an explanatory view of another way of taking out the slurry-like cool storage material after the cool storage is completed from the closed container.

FIG. 4 is an explanatory view of a cold storage base according to the apparatus of FIG. 1, which is composed of a cold storage material production / cumulative storage, a refrigerator, and a transport means.

5 is an explanatory diagram of another cold storage base according to the apparatus of FIG. 1, which is composed of a refrigerator, a manufacturing unit, a storage unit provided with cold storage means, and a transport means.

6 is an explanatory diagram of still another cold storage base according to the apparatus of FIG. 1, which has a configuration in which a filter is provided in the storage unit of FIG.

FIG. 7 is an explanatory view of a blade of an apparatus for manufacturing a slurry regenerator material according to an embodiment of the present invention, FIG. 7 (A) is a plan view of the blade, and FIG. 7 (B) is a front view.

FIG. 8 is a characteristic diagram showing the relationship between the average particle size of water and HLB in a W / O type emulsion and an O / W type emulsion.

FIG. 9 is a characteristic diagram showing the relationship between the freezing point and HLB in W / O type emulsions and O / W type emulsions.

[Explanation of symbols]

1 ... Manufacturing unit, 2 ... Airtight container,
3 ... take-out port, 4 ... return port, 5 ... phase change substance, 6 ... substance, 7 ... surfactant, 8
... Cooling material material, 9 ... Cooling means, 11 ... Spring, 12 ... Motor, 13 ... Shaft, 21 ... Cold storage base (main implant),
22 ... Joint, 23 ... moving body, 24 ... cooling material receiving space, 25 ... subplant, 26 ... cooling material manufacturing and storage section, 27 ... refrigerator, 28,31 ... conveying means, 29 ... cooling means,
30 ... Storage, 32 ... Filter, 41 ... Stay,
42 ... blade (scraping blade),
42a ... unevenness.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Koyoshi Terao, 1-1, Showa-cho, Kariya city, Aichi prefecture, Nihon Denso Co., Ltd. (72) Inventor, Akihiro Koyama, 1-1, Showa-cho, Kariya city, Aichi prefecture Incorporated (72) Inventor Ryumi Gamo 1-1, Showa-cho, Kariya city, Aichi Prefecture Nihondenso Co., Ltd.

Claims (3)

[Claims] 1. A phase change material, and a material which is incompatible with the phase change material and has a lower freezing point than the phase change material,
A regenerator material comprising a surfactant that improves the mixed state of the two substances. 2. The hydrophilic-lipophilic balance of the interfacial lubricant is 9
The regenerator material according to claim 1, which is -11. 3. A manufacturing apparatus comprising a closed container, a cooling means for cooling the closed container, a rotatable scraping blade provided in the closed container, and a drive source for rotating the scraping blade. In the method for producing a regenerator material using, a phase change substance, a substance that is incompatible with the phase change substance and has a lower freezing point than the phase change substance, and a surfactant that improves the mixed state of the two substances. A method for producing a cold storage material, comprising: putting a cold storage material raw material containing: into a closed container, scraping off the phase change material that undergoes solid phase growth on an inner wall surface of the closed container with a scraping blade to obtain a slurry cold storage material.