JP2018071939A - Latent heat storage body and manufacturing method of latent heat storage body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a latent heat storage body excellent in mechanical strength with a relatively light weight, and capable of facilitating latent heat storage for waste heat in a low temperature range, and a manufacturing method of the latent heat storage body.SOLUTION: A latent heat storage body 1 includes a latent heat storage member 10 composed of an organic compound, and a metal film 20, as a metal seamless capsule, configured to encapsulate the latent heat storage member 10 therein. A manufacturing method of the latent heat storage body 1 comprises: on a surface of the latent heat storage member 10, applying powder of copper oxide; after electroless copper plating with the powder and plating catalyst as deposition origin, performing electrolytic copper plating to form the metal film 20; and encapsulating the latent heat storage member 10 inside the metal film 20.SELECTED DRAWING: Figure 1

Description

  The technology disclosed herein relates to a latent heat storage body that performs heat storage using a solid-liquid phase change of a substance and a method for manufacturing the same.

  As a conventional latent heat storage body, for example, there is a latent heat storage capsule disclosed in Patent Document 1 below. This latent heat storage capsule includes a latent heat storage material and a metal film that covers the surface of the latent heat storage material. The disclosed latent heat storage body has a relatively high mechanical strength because the surface of the latent heat storage material is covered with a metal film.

Japanese Patent Laid-Open No. 11-23172

  However, in the above-described conventional latent heat storage body, the latent heat storage material is a metal such as lead and the temperature at which the solid-liquid phase changes is relatively high. For this reason, there is a problem that it is difficult to store heat as a latent heat of waste heat in a low temperature region that is discarded in large quantities in the industrial world. Moreover, when metals, such as lead, are used for a latent heat storage material, since the specific gravity of a latent heat storage material is comparatively large, there exists a problem that the weight of a latent heat storage body will become very large.

  The technology disclosed herein has been made in view of the above points, and is a latent heat storage body that is relatively lightweight and excellent in mechanical strength and can easily store latent heat of low-temperature waste heat and its manufacture. It aims to provide a method.

In order to achieve the above object, in the disclosed latent heat storage body,
A latent heat storage member (10) composed of an organic compound;
And a metal seamless capsule (20) enclosing the latent heat storage member therein.

  According to this, the latent heat storage member can be composed of an organic compound having a relatively small specific gravity and a relatively low melting point. Moreover, the capsule which encloses a latent-heat storage member inside can be made from a comparatively high intensity | strength seamless metal without a junction part. Therefore, it is comparatively lightweight and excellent in mechanical strength, and the waste heat in the low temperature region can be easily stored as latent heat.

In the disclosed method for manufacturing a latent heat storage body,
A preparation step (110) for preparing a granular latent heat storage member (10) composed of an organic compound;
A powder supporting step (120) of pressing the powder of metal or metal oxide (30) on the surface of the latent heat storage member prepared in the preparation step, and supporting the powder on the latent heat storage member;
An electroless plating step (130) of forming a first plating layer (21) on the surface of the latent heat storage member by an electroless plating method using a plating catalyst as a starting point for deposition by applying a plating catalyst to the surface of the latent heat storage member; ,
An electroplating step (140) for forming a second plating layer (22) on the surface of the first plating layer by an electroplating method after the electroless plating step;
A latent heat storage body is manufactured in which a latent heat storage member is enclosed in a metal seamless capsule (20) having a first plating layer and a second plating layer.

  According to this, the surface of the granular latent heat storage member prepared in the preparation step can be easily covered with the first plating layer and the second plating layer formed in the electroless plating step and the electrolytic plating step. In addition to providing the catalyst for electroless plating, by performing the powder supporting process, the electroless plating process can cover the latent heat storage member relatively uniformly and form a first plating layer in close contact with the latent heat storage member. it can. In the electrolytic plating process, the second plating layer whose film thickness is relatively easy to control can be deposited starting from the first plating layer. Therefore, the capsule which encloses the granular latent heat storage member comprised with an organic compound inside can be made of a relatively high-strength seamless metal having the first plating layer and the second plating layer. In this way, it is possible to produce a latent heat storage body that is relatively lightweight and excellent in mechanical strength and that can easily store latent heat of waste heat in a low temperature region.

  In addition, the code | symbol in the parenthesis described in a claim and this clause shows the correspondence with the specific means as described in embodiment mentioned later as one aspect, Comprising: The range of an indication technique is limited It is not a thing.

It is sectional drawing which shows schematic structure of the latent heat storage body which concerns on 1st Embodiment. It is a partial expanded sectional view of the II section of the latent heat storage body shown in FIG. It is sectional drawing which shows schematic structure of a latent heat storage body when a latent heat storage member is a liquid phase state. It is sectional drawing which shows an example of schematic structure of a latent heat storage body when a latent heat storage member is a solid-phase state. It is a flowchart which shows the manufacturing process flow of a latent heat storage body. It is explanatory drawing of the granule preparation process of a latent heat storage member. It is sectional drawing which shows schematic structure of the granular material produced at the granular material production process. It is explanatory drawing of the powder application | coating process which apply | coats powder on the surface of a latent heat storage member. It is sectional drawing which shows typically the structure of the latent heat storage member with which powder was apply | coated. It is explanatory drawing of an electroless-plating process. It is sectional drawing which shows typically the structure of the latent-heat heat storage member coat | covered with the 1st plating layer by electroless plating.

  Hereinafter, a plurality of modes for carrying out the disclosed technology will be described with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. In the case where only a part of the configuration is described in each embodiment, the other parts of the configuration are the same as those described previously. In addition to the combination of parts specifically described in each embodiment, the embodiments may be partially combined as long as the combination is not particularly troublesome.

(First embodiment)
A first embodiment to which the disclosed technology is applied will be described with reference to FIGS.

  As shown in FIG. 1, the latent heat storage body 1 of this embodiment includes a latent heat storage member 10 made of an organic compound, and a metal film 20 formed so as to accommodate the latent heat storage member 10 therein. Yes. The latent heat storage body 1 is a granular body having, for example, a spherical outer shape and an outer diameter of about 4 mm. The metal film 20 is made of a plating film and does not have a joint or the like. The metal film 20 corresponds to the seamless capsule in the present embodiment.

  The latent heat storage body 1 exchanges heat with, for example, cooling water of an internal combustion engine mounted on a vehicle. For example, a plurality of latent heat storage bodies 1 are aggregated and arranged in the coolant flow path. When the temperature of the cooling water is relatively high, the latent heat storage body 1 receives the waste heat of the cooling water, and the latent heat storage member 10 changes phase from the solid phase state to the liquid phase state to store heat as latent heat. To do. When the temperature of the cooling water is relatively low, the latent heat storage member 10 changes phase from the liquid phase state to the solid phase state and releases latent heat to the cooling water.

  The latent heat storage member 10 can contain, for example, dotria contane, which is a normal paraffin having 32 carbon atoms, as a main component. When the organic compound constituting the latent heat storage member 10 is dotriacontane, the latent heat storage member 10 has a melting point of 69 ° C. The latent heat storage member 10 has a freezing point of 69 ° C. The latent heat storage member 10 has a phase transition temperature of 69 ° C. at which the liquid phase and the solid phase can coexist. The melting point and the freezing point are temperatures defined based on, for example, JISK7121. The material constituting the latent heat storage member 10 of this example is provided by Paraffin Wax-155 manufactured by Nippon Seiwa Co., Ltd., for example.

  When the temperature of the cooling water flowing along the outer surface of the latent heat storage body 1 is higher than the melting point, the latent heat storage member 10 receives and melts the heat of the cooling water via the metal film 20. When the temperature of the cooling water flowing along the outer surface of the latent heat storage body 1 is lower than the melting point, the latent heat storage member 10 is solidified and radiates heat to the cooling water through the metal film 20.

  The organic compound constituting the latent heat storage member 10 is not limited to dotriacontane. The organic compound constituting the latent heat storage member 10 preferably has a melting point of 40 ° C to 90 ° C. The lower limit of a suitable temperature range determined based on the thermal efficiency of the internal combustion engine is, for example, 40 ° C., and the upper limit is, for example, 90 ° C. When the internal combustion engine is mounted on a vehicle, for example, 40 ° C. is set as the cooling water temperature when the warm-up is completed. Further, for example, 90 ° C. is set as the cooling water temperature in the general steady travel mode. Therefore, if the melting point of the organic compound constituting the latent heat storage member 10 is in the range of 40 ° C. to 90 ° C., the waste heat of the cooling water during steady running is stored in the latent heat storage member 10 to restart the internal combustion engine, etc. Can be used for warming up.

  As the organic compound constituting the latent heat storage member 10, normal paraffin having 21 to 46 carbon atoms can be used. Heikosan, which is a normal paraffin having 21 carbon atoms, has a melting point of 40.5 ° C. Further, hexatetracontane, which is a normal paraffin having 46 carbon atoms, has a melting point of 86 ° C to 89 ° C. Therefore, the phase transition temperature of the latent heat storage member 10 can be set in the range of 40 ° C. to 90 ° C. by using normal paraffin having 21 to 46 carbon atoms alone or in combination.

  As an example of the outer diameter of the latent heat storage body 1, that is, the outer diameter of the metal film 20, the outer diameter of the latent heat storage body 1 is preferably 1 mm to 10 mm. When the outer diameter is less than 1 mm, the latent heat storage body 1 becomes a fine powder and is relatively difficult to handle. Moreover, if an outer diameter exceeds 10 mm, the specific surface area of the latent heat storage body 1 will become small, and the heat transfer between cooling water will become inefficient. Therefore, the outer diameter of the latent heat storage body 1 is preferably 1 mm to 10 mm. The outer diameter of the latent heat storage body 1 is more preferably 2 mm to 7 mm, and even more preferably 2.5 mm to 5 mm.

  The metal film 20 is made of, for example, copper. That is, the metal film 20 is composed of a copper plating film. The average thickness t of the metal film 20 is, for example, 50 μm. Therefore, in this example, the average thickness t of the metal film 20 is about 1.25% of the outer diameter of the metal film 20. The average thickness t of the metal film 20 is preferably 0.7% to 10% of the outer diameter of the metal film 20. When the average thickness t is less than 0.7% of the outer diameter of the metal film 20, it is difficult to ensure the mechanical strength of the metal film 20. In addition, when the average thickness t exceeds 10% of the outer diameter of the metal film 20, the volume ratio of the metal film 20 to the latent heat storage member 10 becomes too large. Accordingly, the average thickness t of the metal film 20 is preferably 0.7% to 10% of the outer diameter. Further, the average thickness t of the metal film 20 is more preferably 1% to 4% of the outer diameter.

  As shown in FIG. 2, the thickness of the metal film 20 may vary slightly depending on the position in the surface extending direction. The variation in the thickness of the metal film 20 is preferably within ± 30% with respect to the average thickness t. If the thickness of the metal film 20 varies outside the range of + 30% to -30% with respect to the average thickness t, the metal film 20 is likely to buckle or break when the internal / external pressure difference increases. Become. Therefore, the variation in the thickness of the metal film 20 is preferably within ± 30% with respect to the average thickness t. The variation in the thickness of the metal film 20 is more preferably within ± 25% with respect to the average thickness t.

  In addition, the thickness of the metal film 20 in the above description includes the dimension of the portion where the inner surface of the metal film 20 protrudes and bites into the latent heat storage member 10, as is apparent from the range of the average thickness t shown in FIG. Absent. The protruding portion of the metal film 20 is a protruding portion caused by the powder 30 used when manufacturing the latent heat storage body 1 described later. That is, the preferable average film thickness t and thickness variation of the metal film 20 are based on the thickness dimension that does not include the convex portion.

  As shown in FIG. 1, a cavity 11 in which the solid phase latent heat storage member 10 does not exist is formed inside the metal film 20. That is, when the latent heat storage member 10 is in the solid phase, the latent heat storage member 10 occupies a part of the inner region of the metal film 20, and the remaining portion of the inner region is the cavity 11. The inside of the cavity 11 is preferably a vacuum. The cavity 11 may have some gas. The cavity 11 can accept the volume expansion of the latent heat storage member 10 when the latent heat storage member 10 changes phase and becomes a liquid phase. Therefore, the volume of the cavity 11 is preferably equal to or greater than the difference between the volume when the latent heat storage member 10 is in the liquid phase and the volume when it is in the solid phase.

  In the latent heat storage body 1 shown in FIG. 1, the latent heat storage member 10 is in a solid phase. When the latent heat storage member 10 absorbs heat from cooling water, which is a heat transport medium flowing outside the latent heat storage body 1, and enters a liquid phase state, the cavity 11 disappears, for example, as shown in FIG. If the volume of the cavity 11 in FIG. 1 is larger than the volume increase accompanying the phase change of the latent heat storage member 10, the cavity 11 will only become small and will not disappear. When the latent heat storage member 10 radiates heat to the cooling water flowing outside the latent heat storage body 1 and enters a liquid phase again, a cavity 11 is formed between the latent heat storage member 10 and the metal film 20 as shown in FIG. Is done. The cavity 11 when the latent heat storage member 10 is in the solid phase may be formed so as to be included in the latent heat storage member 10, or may be formed between the latent heat storage member 10 and the metal film 20. .

  Next, a method for manufacturing the latent heat storage body 1 having the above-described configuration will be described. When manufacturing the latent heat storage body 1, as shown in FIG. 5, the granular material production process 110, the powder application process 120, the electroless plating process 130, and the electrolytic plating process 140 are sequentially performed.

  In the granule preparation step 110, as shown in FIG. 6, the droplet 10A, which is a particle of a latent heat storage member that has been melted into a liquid phase, is a cooling liquid that is stored in the cooling tank 92 from the tip of the nozzle 90. It is dropped into the cooling water 91. The cooling liquid is preferably a liquid that is not compatible with the organic compound constituting the latent heat storage member 10. Since the latent heat storage member 10 of this example is a water-insoluble normal paraffin, the cooling liquid is the cooling water 91. The droplet 10 </ b> A dropped on the cooling water 91 is cooled by the cooling water 91 and solidified from the outside, and becomes a granular latent heat storage member 10. Since the droplets 10A are sequentially solidified from the outside, the latent heat storage member 10 in a solid state is provided with a cavity 11 having a volume of a volume decrease of several percent accompanying the phase change as shown in FIG. Formed in the part.

  The step of forming the granular latent heat storage member 10 shown in FIG. 7 by the method shown in FIG. The granular material manufacturing step 110 is not limited to the method of dropping the droplet 10A of the latent heat storage member into the cooling water 91. For example, the nozzle 90 may be disposed so that the tip is located in the cooling liquid, and the droplet 10 </ b> A may be supplied into the cooling water 91. The posture of the nozzle 90 is not limited to the illustrated one, and the droplet 10 </ b> A may be supplied into the cooling water 91 from the side or the lower side with respect to the cooling tank 92.

  In this embodiment, the granule preparation step 110 corresponds to a preparation step of preparing the granular latent heat storage member 10 made of an organic compound. In addition, a preparation process is not limited to the granule preparation process 110, For example, the process of preparing the latent heat storage member 10 as shown in FIG. 7 and supplying it to a post process may be sufficient.

  In the powder application step 120, as shown in FIG. 8, the granular latent heat storage member 10 and the powder 30 created in the granule preparation step 110 are accommodated in the container 93, and the powder 30 is applied to the surface of the latent heat storage member 10. To do. In the powder application step 120, the powder 30 is pressed against the latent heat storage member 10 with an urging force that causes plastic deformation of the vicinity of the surface of the latent heat storage member 10, and the latent heat storage member 10 carries the powder 30 as shown in FIG.

  For example, the container 93 is a glass container, the latent heat storage member 10 and the powder 30 are mixed by a device that rotates the container 93, the powder 30 is pressed against the latent heat storage member 10 along with the rotary mixing, and the powder 30 is applied to the latent heat storage member 10. Can be supported. Further, for example, the container 93 is a polyethylene bag, the powder 30 is pressed against the latent heat storage member 10 by pressing the powder 30 against the latent heat storage member 10 while mixing the latent heat storage member 10 and the powder 30 in the bag and mixing the powder 30 against the latent heat storage member 10. Can be supported.

  The powder 30 may be at least one of copper powder and copper oxide powder. In this example, the powder 30 is a cubic copper oxide powder, and a powder having an average particle diameter of about 10 μm is used. The particle size of the powder 30 is preferably 1 μm to 100 μm. When the powder particle size is in this range, the latent heat storage member 10 is likely to carry the powder 30, and the plating layer is easily formed stably in the electroless plating step 130 which is a subsequent step. In this example, a copper oxide powder having a particle size distribution range of 1 μm to 20 μm and an average particle size of about 10 μm is used.

  The powder 30 is preferably a polyhedral particle having an average particle diameter smaller than the average thickness t of the metal film 20 of the latent heat storage body 1. By reducing the average particle diameter of the powder 30 and reducing the average thickness t of the metal coating 20, an increase in thickness variation of the metal coating 20 can be suppressed when the metal coating 20 is formed. Moreover, by making the shape of the powder 30 into a polyhedral shape, when the powder 30 is pressed against the latent heat storage member 10, stress can be concentrated on the corners and the powder 30 can be reliably supported on the latent heat storage member 10. . Here, the particle diameter of the polyhedral shape including the cubic shape can be, for example, a diagonal dimension having the longest diameter dimension length.

  In the present embodiment, the powder application step 120 corresponds to a powder carrying step in which a metal or metal oxide powder is pressed against the surface of the latent heat storage member 10 to carry the powder on the latent heat storage member.

  As shown in FIG. 5, after the powder coating process 120 is completed, an electroless plating process 130 is performed. The electroless plating process 130 includes a catalyst application process 131, a water washing process 132, a catalyst activation process 133, a water washing process 134, an electroless copper plating process 135, and a water washing / drying process 136. In the electroless plating step 130, the above steps are performed in the order described above.

  In the catalyst application step 131, a catalyst is applied to the surface of the latent heat storage member 10 using a catalyst solution. The catalyst solution is, for example, a mixed solution of stannous chloride and palladium chloride. The latent heat storage member 10 carrying the powder 30 is immersed in a palladium-tin mixed colloidal solution to give a catalyst to the surface. Although the powder 30 is supported on the surface of the latent heat storage member 10 in the powder application step 120, a part of the powder 30 may fall off the surface of the latent heat storage member 10 until the catalyst application step 131. However, since the powder 30 once biting into the latent heat storage member 10 falls off, the latent heat storage member 10 plastically deformed is formed with a recess at the powder desorption site. Even if the powder 30 is detached from the latent heat storage member 10, in the catalyst application step 131, the catalyst is surely applied using this recess.

  After performing the catalyst provision process 131, the catalyst activation process 133 is performed through the water washing process 132. FIG. In the catalyst activation step 133, for example, an acceleration treatment is performed to remove tin from the palladium-tin mixed colloid to expose the metallic palladium. The acceleration treatment is an acid treatment in which the latent heat storage member 10 is immersed in an acidic aqueous solution such as dilute hydrochloric acid or dilute sulfuric acid.

  After performing the catalyst activation process 133, the electroless copper plating process 135 is performed through the water washing process 134. FIG. In the electroless copper plating step 135, for example, a barrel plating apparatus is used as shown in FIG. The barrel plating apparatus includes, for example, a barrel 96 that is porous and rotatable in a plating bath 94 that stores a plating solution 95 therein. A copper plating layer is formed on the surface of the latent heat storage member 10 in the barrel 96.

  At this time, the average density of the latent heat storage member 10 is smaller than the average density of the plating solution 95. That is, the latent heat storage member 10 tends to float toward the liquid level 95 a in the plating solution 95. In the present embodiment, a large number of granular latent heat storage members 10 are accommodated in a mesh bag 97 made of, for example, polyvinylidene chloride and disposed in a barrel 96. This suppresses the floating of the latent heat storage member 10 so that the latent heat storage member 10 does not protrude upward from the liquid surface 95 a of the plating solution 95. That is, the latent heat storage member 10 is pressed from above by the mesh bag 97 so that the entire latent heat storage member 10 is positioned below the liquid surface of the plating solution 95. By accommodating the latent heat storage member 10 in the mesh bag 97 having a finer particle size than the particle size, it is possible to prevent the granular latent heat storage member 10 from flowing out through a relatively large hole formed in the barrel 96.

  In the electroless copper plating step 135, the powder 30 carried on the latent heat storage member 10 and the palladium catalyst applied to the surface of the latent heat storage member 10 are the copper plating layers as shown in FIG. A first plating layer 21 is formed. In the electroless copper plating step 135, the copper oxide constituting the powder 30 is reduced and functions as a starting point for the electroless copper plating. When the electroless copper plating step 135 is executed, a water washing / drying step 136 is executed.

  In the electroless plating step 130, the environmental temperature of the latent heat storage member 10 is managed to be lower than the melting point of the material constituting the latent heat storage member 10 through the catalyst application step 131 to the water washing / drying step 136. As in this example, when the organic compound constituting the latent heat storage member 10 is dotriacontane, the latent heat storage member 10 has a melting point of 69 ° C. In this example, the liquid temperature in the catalyst application step 131 is 30 ° C. Further, the liquid temperature in the catalyst activation step 133 is equivalent to room temperature, which is normal temperature. Further, the temperature of the plating solution 95 in the electroless copper plating step 135 is set to 33 ° C. Accordingly, in the electroless plating step 130, the first plating layer 21 can be formed without breaking the grain shape of the latent heat storage member 10.

  By the electroless plating step 130, the first plating layer 21 having a thickness of, for example, about 1 μm is formed on the entire surface of the latent heat storage member 10. The first plating layer 21 is preferably formed to a thickness of 0.5 μm to 2 μm.

  As shown in FIG. 5, after the electroless plating step 130 is completed, an electrolytic plating step 140 is performed. The electrolytic plating process 140 includes an acid activation process 141, a water washing process 142, an electrolytic copper plating process 143, and a water washing / drying process 144. In the electrolytic plating step 140, the above steps are performed in the order described above.

  In the acid activation step 141, the surface of the first plating layer 21 is activated using an acidic aqueous solution such as dilute sulfuric acid. After performing the acid activation process 141, the electrolytic copper plating process 143 is performed through the water washing process 142. FIG. In the electrolytic copper plating step 143, for example, a barrel plating apparatus is used as in the electroless copper plating step 135. A copper plating layer is further formed on the surface of the first plating layer 21 covering the entire surface of the latent heat storage member 10 in the barrel of the barrel plating apparatus. In the electrolytic copper plating step 143, for example, electrolytic copper plating is performed to deposit copper on the surface of the first plating layer 21 of the latent heat storage member 10 using a copper pyrophosphate plating solution. In the electrolytic copper plating step 143, for example, a current of 4A is applied.

  Also in the electrolytic copper plating step 143, the average density of the latent heat storage member 10 including the first plating layer 21 is smaller than the average density of the plating solution. That is, the latent heat storage member 10 including the first plating layer 21 tends to float toward the liquid surface in the plating solution. In this embodiment, also in the electrolytic copper plating step 143, as in the electroless copper plating step 135, a large number of granular latent heat storage members 10 are accommodated in, for example, a mesh bag made of polyvinylidene chloride and disposed in the barrel. doing. Thereby, the floating of the latent heat storage member 10 is suppressed so that the latent heat storage member 10 does not protrude upward from the surface of the plating solution. That is, the latent heat storage member 10 is pressed from above with a mesh bag so that the entire first plating layer 21 is positioned below the surface of the plating solution. By storing the latent heat storage member 10 in a mesh bag having a finer particle size than the particle size, it is possible to prevent the granular latent heat storage member 10 from flowing out through a relatively large hole formed in the barrel.

  In the electrolytic copper plating step 143, as shown in FIG. 2, the second plating layer 22 which is a copper plating layer is formed using the first plating layer 21 covering the entire surface of the latent heat storage member 10 as a deposition starting point. The thickness of the second plating layer 22 is, for example, 50 μm. By forming the second plating layer 22 so as to overlap the first plating layer 21, the metal film 20 having the first plating layer 21 and the second plating layer 22 is formed. When the electrolytic copper plating step 143 is executed, a water washing / drying step 144 is executed.

  In the electrolytic plating process 140, the environmental temperature of the latent heat storage member 10 is managed to be lower than the melting point of the material constituting the latent heat storage member 10 through the acid activation process 141 to the water washing / drying process 144. As in this example, when the organic compound constituting the latent heat storage member 10 is dotriacontane, the latent heat storage member 10 has a melting point of 69 ° C. In this example, the liquid temperature in the acid activation step 141 is equivalent to room temperature, which is room temperature. Further, the temperature of the plating solution in the electrolytic copper plating step 143 is set to 55 ° C. As a result, in the electrolytic plating step 140, the second plating layer 22 can be formed without breaking the grain shape of the latent heat storage member 10 covered with the first plating layer 21.

  According to the latent heat storage body 1 having the above-described configuration, the following effects can be obtained.

  The latent heat storage body 1 includes a latent heat storage member 10 made of an organic compound and a metal film 20 that is a metal seamless capsule that encloses the latent heat storage member 10 therein. According to this, the latent heat storage member 10 can be composed of an organic compound having a relatively small specific gravity and a relatively low melting point. Moreover, the metal film 20 which is a capsule which encloses the latent heat storage member 10 inside can be made of a relatively high-strength seamless metal having no joints or the like. Therefore, the latent heat storage body 1 is relatively lightweight and excellent in mechanical strength, and can easily store waste heat in a low temperature region as latent heat.

  When the latent heat storage body 1 is mounted on a vehicle as in this embodiment, it is advantageous from the viewpoint of vehicle weight and vehicle mountability that the latent heat storage body 1 is relatively lightweight. In addition, since the latent heat storage body 1 is lightweight and excellent in mechanical strength, it is easy to maintain the structure of the latent heat storage body 1 even in a vehicle-mounted environment where a relatively large vibration may be applied. Furthermore, even when the internal combustion engine mounted on the vehicle repeats operation and stop and the amount of heat released from the internal combustion engine to the cooling water largely fluctuates with time, the cooling water temperature is changed by the phase change of the latent heat storage member 10. Is easily maintained within a predetermined temperature range.

  Even if the phase change of the latent heat storage member 10 is frequently repeated and a repeated stress is applied due to fluctuations in the internal / external pressure difference of the metal film 20, the seamless metal film 20 can withstand this. In the case of a comparative example in which a metal film is formed on a metal particle such as lead, an expansion pressure is applied to the metal film when the metal particle changes to the liquid phase, and the metal film is destroyed when the solid-liquid phase change is repeated. There is a problem that it ends up. According to the latent heat storage body 1 of the present embodiment, such a problem hardly occurs and high durability can be easily ensured.

  The metal film 20 has an outer diameter of 1 mm to 10 mm. According to this, by making the outer diameter 10 mm or less, the specific surface area of the latent heat storage body is made relatively large, and heat transfer between the latent heat storage member 10 inside the metal film 20 and the external heat transport medium is easy. Can be. Moreover, the handling of the latent heat storage body 1 is easy by making an outer diameter 1 mm or more, and it is excellent in manufacturability.

  The organic compound constituting the latent heat storage member 10 has a melting point of 40 ° C to 90 ° C. According to this, waste heat in a relatively low temperature region that is equal to or higher than the phase transition temperature that is the melting / solidification temperature can be easily stored and radiated at a relatively low phase transition temperature.

  The organic compound constituting the latent heat storage member 10 is normal paraffin having 21 to 46 carbon atoms. Heikosan, which is a normal paraffin having 21 carbon atoms, has a melting point of 40.5 ° C, and hexatetracontane, which is a normal paraffin having 46 carbon atoms, has a melting point of 86 ° C to 89 ° C. Therefore, waste heat in a relatively low temperature region that is equal to or higher than the phase transition temperature that is the melting / solidification temperature can be easily stored and radiated at a relatively low phase transition temperature.

  Further, when the latent heat storage member 10 is in a solid phase, the latent heat storage member 10 occupies a part of the inner region of the metal film 20, and the cavity 11 is formed in the remaining portion of the inner region. According to this, even if the latent heat storage member 10 undergoes volume expansion when the phase changes from the solid phase state to the liquid phase state, the expansion can be received in the cavity 11 portion. Therefore, it is easy to suppress an increase in internal pressure when the phase is changed from the solid phase to the liquid phase.

  The volume of the cavity 11 is not less than the volume difference between the volume when the latent heat storage member 10 is in a liquid phase and the volume when it is in a solid phase. According to this, the volume expansion part accompanying the phase change from the solid phase state of the latent heat storage member 10 to a liquid phase state can be reliably received by the cavity 11 part. Therefore, it is possible to reliably suppress an increase in internal pressure when the phase is changed from the solid phase state to the liquid phase state.

  The metal film 20 is made of copper. According to this, it is possible to provide a metal film which is excellent in thermal conductivity and is a relatively inexpensive seamless capsule.

  The average thickness of the metal film 20 is 0.7% to 10% of the outer diameter. According to this, the volume ratio of the metal film 20 to the latent heat storage member 10 can be suppressed while ensuring the mechanical strength. Therefore, heat conduction can be performed relatively efficiently, and the latent heat storage body 1 can be reduced in weight. Moreover, the metal film 20 can be manufactured relatively easily.

  Further, the metal film 20 has a variation in thickness within ± 30% of the average thickness. According to this, even if the difference between the internal and external pressures of the metal film 20 is relatively large, the metal film 20 is unlikely to break or buckle.

  Moreover, according to the manufacturing method of the above-mentioned latent heat storage body 1, the effect described below can be acquired.

  The disclosed manufacturing method of the latent heat storage body 1 includes a granular material production process 110 that is a preparation process, a powder application process 120 that is a powder carrying process, an electroless plating process 130, and an electrolytic plating process 140. In the preparation step, a granular latent heat storage member 10 made of an organic compound is prepared. In the powder carrying step, the powder 30 of metal or metal oxide is pressed against the surface of the latent heat storage member 10 prepared in the preparation step, and the powder 30 is carried on the latent heat storage member 10. In the electroless plating step 130, a plating catalyst is applied to the surface of the latent heat storage member 10, and the first plating layer 21 is formed on the surface of the latent heat storage member by the electroless plating method using the powder 30 and the plating catalyst as a deposition starting point. In the electroplating step 140, after the electroless plating step 130, the second plating layer 22 is formed on the surface of the first plating layer 21 by an electrolytic plating method. Through the above process group, the latent heat storage body 1 in which the latent heat storage member 10 is sealed inside the metal film 20 having the first plating layer 21 and the second plating layer 22 is manufactured.

  According to this, the surface of the granular latent heat storage member 10 prepared in the preparation step can be easily covered with the first plating layer 21 and the second plating layer 22 formed in the electroless plating step 130 and the electrolytic plating step 140. it can. In the electroless plating process 130, the first plating layer 21 that covers the latent heat storage member 10 relatively uniformly and is in close contact with the latent heat storage member 10 is formed by performing not only the electroless plating catalyst application but also the powder supporting process. Can be formed. In the electrolytic plating process 140, the second plating layer 22 whose film thickness is relatively easy to control can be deposited starting from the first plating layer 21. Therefore, the capsule encapsulating the granular latent heat storage member 10 made of an organic compound can be made of a relatively high-strength seamless metal having the first plating layer 21 and the second plating layer 22. In this way, it is possible to manufacture the latent heat storage body 1 that is relatively lightweight and excellent in mechanical strength and can easily store latent heat of waste heat in a low temperature region.

  In the powder supporting step, at least one of the same metal powder and the same metal oxide powder as the metal forming the first plating layer 21 is supported. According to this, in the electroless plating step 130, it is easy to deposit the first plating layer 21 starting from powder as well as the catalyst.

  In the powder supporting step, the powder 30 having a powder particle size of 1 μm to 100 μm is supported. According to this, in the powder carrying process, the latent heat storage member 10 can easily carry the powder, and in the electroless plating process 130, the first plating layer 21 can be formed stably.

  In the electroless plating step 130, the latent heat storage member 10 is pressed from above, and the entire latent heat storage member 10 is positioned below the liquid level 95 a of the plating solution 95. According to this, even if the average density of the granular latent heat storage member 10 is smaller than the density of the plating solution 95 in the electroless plating step 130, the first plating layer 21 extends over the entire surface of the latent heat storage member 10. Can be formed stably.

  Moreover, in the electroplating process 140, the latent heat storage member 10 with the first plating layer 21 formed on the surface is pressed from above, and the entire first plating layer 21 is positioned below the liquid surface of the plating solution. According to this, even when the average density of the latent heat storage member 10 having the first plating layer 21 is smaller than the density of the plating solution in the electroplating step 140, it covers the entire outer surface of the first plating layer 21. The second plating layer 22 can be formed stably.

  Further, in the preparation step, the droplet 10A of the latent heat storage member 10 is supplied into the cooling water 91 that is a cooling liquid and solidified from the outside to form the granular latent heat storage member 10. According to this, when forming the granular latent heat storage member 10, the liquid phase latent heat storage member 10 can be sequentially solidified from the outside. Therefore, the granular latent heat storage member 10 having the cavity 11 inside can be easily formed.

(Other embodiments)
The technology disclosed in this specification is not limited to the embodiment for carrying out the disclosed technology, and can be implemented with various modifications. The disclosed technology is not limited to the combinations shown in the embodiments, and can be implemented in various combinations. Embodiments can have additional parts. The portion of the embodiment may be omitted. The parts of the embodiments can be replaced or combined with the parts of the other embodiments. The structure, operation, and effect of the embodiment are merely examples. The technical scope of the disclosed technology is not limited to the description of the embodiments. Some technical scope of the disclosed technology is indicated by the description of the claims, and should be understood to include all modifications within the meaning and scope equivalent to the description of the claims. .

  In the said embodiment, although the organic compound which comprises the latent heat storage member 10 was normal paraffin, it is not limited to this. For example, it may be isoparaffin or other organic compound. An organic compound having a phase transition temperature corresponding to the waste heat temperature can be employed in response to a relatively low temperature waste heat discarded in the industry, for example, 40 to 200 ° C. waste heat.

  Moreover, although the said embodiment demonstrated the example which employ | adopted comparatively cheap Cu excellent in heat conductivity as a metal which comprises the metal film 20, the metal which comprises the metal film 20 is not limited to Cu. Absent. As a metal constituting the metal film, a metal capable of causing an autocatalytic electroless reaction, for example, any one of Cu, Ni, Co, Au, Ag, Pd, Rh, Pt, In, Sn is adopted. Can do. Of the metals described above, Cu, Au, or Ag is preferable from the viewpoint of thermal conductivity. Of Cu, Au, and Ag, the relatively inexpensive Cu described in the above embodiment is most preferable.

  Regardless of the type of metal, the average thickness t of the metal film preferably satisfies the following formula (1).

2E / (3 (1-v ² )) ^(1/2) (t / R) ² <101.3 kPa (1)
Here, E is the Young's modulus of the metal film, v is the Poisson's ratio of the metal film, and R is the radius of the metal film.

  Moreover, in the said embodiment, although the powder 30 was at least any one of the copper powder and the copper oxide powder, it is not limited to this. The powder 30 only needs to be a deposition starting point of the first plating layer 21. Therefore, it is preferable that the first plating layer 21 is made of at least one of the same metal and the same metal oxide.

  Moreover, in the said embodiment, although the shape of the powder 30 was a polyhedron shape, it is not limited to this. The shape of the powder may be, for example, a spherical shape. Further, the shape of the powder may be an indefinite shape, for example.

  In the above embodiment, the catalyst treatment method before plating in the electroless plating step 130 is the catalyst-accelerator method in which the palladium in the palladium-tin mixed colloid is removed to expose the metallic palladium. It is not limited to this. For example, a sensitizer-activator method may be employed. Further, for example, an alkali ion catalyst method may be adopted.

  Moreover, in the said embodiment, although the catalyst provision process 131 of the electroless-plating process 130 was performed after the powder application | coating process 120, it is not limited to this. For example, the powder may be carried after the catalyst is applied to the latent heat storage member 10. What is necessary is just to use both the powder and the plating catalyst as the deposition starting point of the plating metal when performing electroless plating.

  In the above embodiment, in the electroless copper plating step 135 and the electrolytic copper plating step 143, the entire latent heat storage member 10 is positioned below the liquid surface of the plating solution using a mesh bag. It is not limited. The latent heat storage member may be pressed below the liquid level using a pressing member other than the mesh bag. Further, the pressing member may be used in steps other than the electroless copper plating step 135 and the electrolytic copper plating step 143.

  Moreover, in the said embodiment, although the latent heat storage body 1 gave and received heat between the cooling water of the internal combustion engine mounted in the vehicle, it is not limited to this. For example, heat may be exchanged with other heat transport media used in the industry. When utilizing relatively low-temperature waste heat discarded in the industry, for example, waste heat of 40 ° C. to 200 ° C., the disclosed technology is widely applied and effective.

1 Latent heat storage body 10 Latent heat storage member 20 Metal film (seamless capsule)
21 1st plating layer 22 2nd plating layer 30 Powder 110 Granule preparation process (preparation process)
120 Powder application process (powder carrying process)
130 Electroless plating process 140 Electrolytic plating process

Claims (15)

A latent heat storage member (10) composed of an organic compound;
A metal seamless capsule (20) enclosing the latent heat storage member therein;
A latent heat storage body comprising   The latent heat storage body according to claim 1, wherein the seamless capsule has an outer diameter of 1 mm to 10 mm.   The latent heat storage body according to claim 1 or 2, wherein the organic compound has a melting point of 40C to 90C.   The latent heat storage body according to claim 1, wherein the organic compound is a normal paraffin having 21 to 46 carbon atoms.   The latent heat storage member occupies a part of the inner region of the seamless capsule when the latent heat storage member is in a solid state, and a cavity (11) is formed in the remaining portion of the inner region. The latent heat storage body according to any one of claims 1 to 4.   The latent heat storage body according to claim 5, wherein the volume of the cavity is equal to or larger than a volume difference between a volume when the latent heat storage member is in a liquid phase and a volume when the latent heat storage member is in a solid phase.   The latent heat storage body according to any one of claims 1 to 6, wherein the seamless capsule is made of copper.   The latent heat storage body according to claim 7, wherein the seamless capsule has an average thickness of 0.7% to 10% of an outer diameter.   The latent heat storage body according to claim 8, wherein the seamless capsule has a thickness variation within ± 30% of the average thickness. A preparation step (110) for preparing a granular latent heat storage member (10) composed of an organic compound;
A powder supporting step (120) of pressing the powder of metal or metal oxide (30) on the surface of the latent heat storage member prepared in the preparation step, and supporting the powder on the latent heat storage member;
An electroless plating process in which a plating catalyst is applied to the surface of the latent heat storage member, and the first plating layer (21) is formed on the surface of the latent heat storage member by an electroless plating method using the powder and the plating catalyst as a deposition starting point. (130),
An electroplating step (140) for forming a second plating layer (22) on the surface of the first plating layer by an electroplating method after the electroless plating step;
A method for producing a latent heat storage body in which the latent heat storage member is enclosed in a metal seamless capsule (20) having the first plating layer and the second plating layer.   The method for producing a latent heat storage body according to claim 10, wherein in the powder supporting step, at least one of the powder of the same metal as the metal forming the first plating layer and the powder of an oxide of the same metal is supported.   The method for producing a latent heat storage body according to claim 11, wherein in the powder supporting step, the powder having a powder particle diameter of 1 μm to 100 μm is supported.   The said electroless-plating process WHEREIN: The said latent heat storage member is pressed down from upper direction, and the whole of the said latent heat storage member is located below the liquid level (95a) of a plating solution (95). A method for producing a latent heat storage body according to claim 1.   In the electrolytic plating step, the latent heat storage member having the first plating layer formed on the surface thereof is pressed from above, and the entire first plating layer is positioned below the liquid surface of the plating solution. The manufacturing method of the latent heat storage body of description.   15. In the preparation step, droplets (10A) of the latent heat storage member are supplied into a cooling liquid (91) and solidified from outside to form the granular latent heat storage member. The manufacturing method of the latent-heat storage body as described in any one of Claims.

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