JP6486079B2 - Method for maintaining heat insulation performance of vacuum insulation panel and method for maintaining heat insulation performance of refrigerator - Google Patents

Description

The present embodiment relates to a method for maintaining the heat insulation performance of the vacuum heat insulation panel and a method for maintaining the heat insulation performance of the refrigerator .

  Conventionally, refrigerators are composed of a heat insulation box filled with foam insulation between the outer box and the inner box, and a storage room is formed inside the heat insulation box, which further improves the heat insulation performance. In order to reduce power consumption, or to reduce the wall thickness of the heat insulation box and improve the internal volume efficiency, replace it with a part of foam insulation filled between the outer box and the inner box. A vacuum insulation panel is provided.

  This type of vacuum heat insulation panel includes a core material and an outer packaging material as disclosed in Patent Document 1, for example. The core material is made of glass wool or the like, which is a thin glass fiber cotton, and the outer packaging material is made of a laminated film bag having aluminum foil or the like. This vacuum heat insulating panel is configured by accommodating a core material in an outer packaging material, reducing the pressure inside the outer packaging material, closing the opening, and holding the inner packaging material in a reduced pressure state.

  However, in the vacuum heat insulating panel, when the outer packaging material of the bag body is damaged at the time of manufacturing the panel or assembling into the cabinet, the external air enters the outer packaging material, and the heat insulating performance is significantly deteriorated. In particular, when fine holes are generated due to the damage of the outer packaging material, external air and moisture enter the outer packaging material even if the fine holes are smaller than several μm. Depending on the size of the holes in the outer packaging material, a slow leak that gradually deteriorates the thermal insulation performance of the vacuum insulation panel over a long period of time, such as several tens of days to several years, occurs. The inside becomes atmospheric pressure, and the heat insulation performance is significantly deteriorated. Therefore, even if sufficient heat insulation performance is confirmed at the time of manufacturing the vacuum heat insulation panel, the heat insulation performance gradually deteriorates thereafter, and it is difficult to ensure the reliability of the heat insulation performance over a long period of time.

  On the other hand, it is conceivable to mix an adsorbent adsorbing water that has entered the outer packaging material such as calcium oxide (CaO) into the core material, but the cost increases and the amount of adsorbent used is increased. There is a limit.

JP 2005-106094 A

  Then, it aims at providing the refrigerator using the vacuum heat insulation panel which can maintain heat insulation performance over a long period of time.

Method of maintaining the heat insulating performance of the vacuum insulation panel according to this embodiment, the vacuum insulation panel comprising an outer cover material for the internal forms a bag shape is depressurized, and a core material having the contained thermal insulation on the outer material In the method for maintaining the heat insulation performance of the first, a first step of forming an inorganic fiber sheet by forming inorganic fibers into a sheet, a second step of applying a hydroxyl group to the inorganic fiber sheet, and a hydroxyl group A third step of enclosing the core material produced using the provided inorganic fiber sheet in the outer packaging material, wherein the hydroxyl group imparted to the inorganic fiber sheet in the second step is the interior of the outer packaging material. The heat insulation performance of the vacuum heat insulation panel is maintained by adsorbing moisture that has entered.

In addition, the method for maintaining the heat insulation performance of the refrigerator according to another embodiment is a method for maintaining the heat insulation performance of the refrigerator in which a vacuum heat insulation panel is provided between the outer box and the inner box. A first step of forming an inorganic fiber sheet by forming an inorganic fiber into a sheet shape, comprising a bag-shaped outer packaging material whose inside is decompressed, and a core material that is housed in the outer packaging material and has heat insulation properties; A second step of performing a treatment for imparting a hydroxyl group to the inorganic fiber sheet, and a third step of enclosing the core material produced using the inorganic fiber sheet imparted with a hydroxyl group in the outer packaging material, In the second step, the hydroxyl group imparted to the inorganic fiber sheet adsorbs moisture that has entered the outer packaging material, thereby maintaining the heat insulating performance of the refrigerator.

It is sectional drawing of the refrigerator which concerns on 1st Embodiment. It is a principal part expanded sectional view of the vacuum heat insulation panel used for the refrigerator shown in FIG. It is a graph which shows the time change of the heat conductivity of the vacuum heat insulation panel of an Example and a comparative example.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the refrigerator 10 of the present embodiment is a refrigerator 10 in which a heat insulating space is provided between an outer box 12 made of a steel plate and an inner box 14 housed in the outer box 12 and forming a storage space. The cabinet 18 is formed by incorporating a refrigeration cycle (not shown) into the cabinet 18.

  On the heat insulation space side of the outer box 12 and the inner box 14 forming the heat insulation space, the vacuum heat insulation panel 50 is not folded, and hot melt or the like is formed so as to be substantially flat along the outer box 12 or the inner box 14. Affixed with an adhesive. The hot melt here includes not only an adhesive using only a thermoplastic resin but also an adhesive used by mixing a thermoplastic resin with a thermoplastic resin. Further, the cabinet 18 may have a gap in a heat insulating space other than the vacuum heat insulating panel 50. In the gap, a foam heat insulating material 20 made of urethane foam or the like, and a refrigerant pipe such as a heat radiating pipe constituting a part of the refrigeration cycle are disposed in the gap, and the outer box 12 and the inner box 14 are integrated. Is done. In particular, a part of the refrigerant pipe such as a heat radiating pipe is disposed by forming a concave groove on the outer casing 12 side of the vacuum heat insulating panel 50 and housing the refrigerant pipe in the concave groove. Therefore, in the vacuum heat insulation panel 50 arranged on the back surface or side surface of the refrigerator 10, the refrigerant pipe and the vacuum heat insulation panel 50 are in contact with each other.

  A storage space provided inside the cabinet 11 is partitioned by an insulating partition wall 22 into an upper refrigerated space and a lower refrigerated space. The refrigerated space is further partitioned vertically by a partition wall 24, a refrigerated room 26 having a plurality of stages of mounting shelves is provided in the upper space, and a vegetable room 28 in which a drawer-type storage container is disposed in the lower space. ing. In the freezing space, an ice making room 30 and a small freezing room 32 equipped with a relatively small volume automatic ice making machine are provided on the left and right, and a freezing room 34 is provided below the ice making room 30.

  FIG. 2 shows a cross section of the end portion of the vacuum heat insulating panel 50. The vacuum heat insulating panel 50 includes a rectangular plate-shaped core member 52 formed in accordance with the shape of the wall portion to be attached, and an outer package that houses the core member 52. Material 54. The shape of the vacuum heat insulating panel is not limited to a rectangular plate shape, and a panel having a free shape such as a polygonal shape with chamfered rectangular corners or a stepped shape having a different thickness depending on a part can be used.

  The core material 52 is formed by storing a laminated material 52a made of a highly heat-insulating material in an inner bag 52b made of a synthetic resin film such as polyethylene, and then compression-cured into a rectangular plate shape. In this example, the laminated material 52a is formed by laminating a plurality of inorganic fiber sheets 52a1 obtained by forming inorganic fibers such as glass wool and silica alumina into a sheet shape.

  The core material 52 may be configured without using the inner bag 52b. That is, the laminated material 52a is not stored in the inner bag 52b, but directly stored in the outer packaging material 54. The laminated material vacuum heat insulation panel 50 is configured by reducing the pressure inside the outer packaging material 54 while the laminated material 52a is housed in a vacuum state.

  The inorganic fiber sheet 52a1 is subjected to a flame treatment in which a flame sprayed from a burner or the like is sprayed on the surface of the inorganic fiber sheet 52a1 to impart hydroxyl groups. In addition to the flame treatment described above, the treatment for imparting hydroxyl groups to the inorganic fiber sheet 52a1 constituting the laminated material 52a may be, for example, a plasma treatment, a corona treatment, or an impregnation treatment with an aqueous sodium hydroxide solution. .

  In addition, the laminated material 52a may be subjected to a treatment for imparting hydroxyl groups as described above to all the inorganic fiber sheets 52a1 constituting the laminate 52a1, and the inorganic fiber sheet 52a1 subjected to a treatment for imparting hydroxyl groups and You may mix and laminate | stack with the inorganic fiber sheet 52a1 before giving the process which provides a hydroxyl group. A vacuum heat insulating panel that can ensure high heat insulation performance over a long period of time by mixing the inorganic fiber sheet 52a1 subjected to the treatment for imparting hydroxyl groups and the inorganic fiber sheet 52a1 prior to the treatment for imparting hydroxyl groups. Can be manufactured at low cost.

  The outer packaging material 54 includes a laminated film having a three-layer structure in which a surface protective layer 54a, a gas barrier layer 54b, and a heat welding layer 54c are sequentially laminated from the outside toward the inside. The surface protective layer 54a is made of a relatively heat-resistant synthetic resin such as polyethylene terephthalate. The gas barrier layer 54b is formed of a metal deposit (eg, an aluminum deposit obtained by depositing aluminum on a resin film) or a metal foil (eg, aluminum foil). The heat welding layer 54c is made of a synthetic resin having a heat welding property such as high density polyethylene.

  The outer packaging material 54 has an opening by heat-sealing and sealing the two laminated films by superimposing and heat-bonding the peripheral portions of the two laminated films with the heat-bonding layers 54c facing each other. It is formed in a bag shape. In the outer packaging material 54, after the core material 52 is accommodated from the opening, the opening of the outer packaging material 54 is sealed by heat welding in a state where the inside is evacuated and decompressed.

  The peripheral portion of the outer packaging material 54 protrudes from the core material 52 in order to thermally weld the two laminated films, and the protruding portion is bent at the edge of the core material 52 and overlapped with one laminated film. A combined folded portion 62 is formed.

  In the refrigerator 10 according to the present embodiment as described above, a process for imparting a hydroxyl group to the inorganic fiber sheet 52a1 constituting the core material 52 accommodated in the outer packaging material 54 is performed. The inorganic fiber sheet 52a1 adsorbs the external moisture that has entered the interior, and high heat insulation performance can be ensured over a long period of time.

  Moreover, in this embodiment, since the process which provides a hydroxyl group to the surface of the sheet-like inorganic fiber sheet 52a is performed, and the core material 52 is formed by laminating a plurality of these, the inside of the core material 52 is uniform. Hydroxyl groups can be imparted to the water and the ability to adsorb moisture that has entered the outer packaging material 54 can be greatly improved.

  In addition, although it is preferable to perform the process which provides a hydroxyl group over the whole core material 52, you may perform the process which provides a hydroxyl group only to a part of core material 52. FIG. That is, for example, when a hydroxyl group is imparted by flame treatment, the core material 52 may be configured by laminating the inorganic fiber sheet 52a in a state where the flame treatment is performed only on the fibers on the surface of the inorganic laminated sheet 52a.

  As mentioned above, although embodiment of this invention was described, these embodiment was shown as an example and is not intending limiting the range of invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the invention described in the claims and equivalents thereof as well as included in the scope and gist of the invention.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to these Examples.

  The vacuum heat insulation panels of the example and the comparative example have the same configuration except for the core material 52, and the example is an inorganic fiber sheet to which a flame treatment is applied and a hydroxyl group is added as the core material 52 accommodated in the outer packaging material 54. The example produced using the laminated material 52a laminated | stacked 52a1 and the comparative example are the laminated materials 52a which laminated | stacked the inorganic fiber sheet 52a1 which has not performed the process which provides a hydroxyl group as the core material 52 accommodated in the outer packaging material 54. It is the example produced using it. In addition, the heat conductivity (initial value) at the time of preparation of each vacuum heat insulation panel was 2.5 mW / mK in all.

  About each vacuum heat insulation panel of an Example and a comparative example, durability of heat insulation performance was evaluated. As the evaluation method, the two types of vacuum heat insulation panels of Examples and Comparative Examples were left in an atmosphere of room temperature 50 ° C. and humidity 80%, and each vacuum heat insulation panel was left for 7 days, 14 days, 21 days and 28 days. The thermal conductivity was measured.

  As a result, as shown in FIG. 3, in the vacuum heat insulation panel of the comparative example in which the treatment for imparting hydroxyl groups was not performed, the thermal conductivity deteriorated from 2.5 mW / mK to 3.9 mW / mK. In the vacuum heat insulation panel of the Example which performed the process to provide, it became 3.0 mW / mK after 28 days, and was able to maintain the heat insulation performance compared with the comparative example.

DESCRIPTION OF SYMBOLS 10 ... Refrigerator, 12 ... Outer box, 14 ... Inner box, 18 ... Cabinet, 20 ... Foam insulation, 22 ... Heat insulation partition, 50 ... Vacuum insulation panel, 52 ... Core material, 52a ... Laminate, 52a1 ... Inorganic fiber sheet , 52b ... inner bag, 54 ... outer package, 54a ... surface protective layer, 54b ... gas barrier layer, 54c ... weld layer, 62 ... folded portion

Claims (6)

In the method of maintaining the heat insulation performance of a vacuum heat insulation panel comprising a bag-shaped outer packaging material whose inside is decompressed, and a core material that is housed in the outer packaging material and has heat insulation properties ,
A first step of forming an inorganic fiber sheet by forming inorganic fiber into a sheet,
A second step of applying a hydroxyl group treatment to the inorganic fiber sheet;
A third step of enclosing the core material produced using the inorganic fiber sheet provided with a hydroxyl group in the outer packaging material,
The method of maintaining the heat insulation performance of a vacuum heat insulation panel by the hydroxyl group provided to the said inorganic fiber sheet in the said 2nd process adsorb | sucking the water | moisture content which entered the inside of the said outer packaging material. The method for maintaining the heat insulation performance of the vacuum heat insulation panel according to claim 1, wherein the treatment is a flame treatment . The method for maintaining the heat insulation performance of the vacuum heat insulation panel according to claim 1, wherein the treatment is a corona treatment or a plasma treatment . The method for maintaining the heat insulation performance of the vacuum heat insulation panel according to claim 1, wherein the treatment is an impregnation treatment with a sodium hydroxide aqueous solution . The said 3rd process WHEREIN: The said inorganic fiber sheet which performed the said process, and the said inorganic fiber sheet before performing the said process are mixed, The said core material is produced of any one of Claims 1-4. A method of maintaining the insulation performance of vacuum insulation panels . In the method of maintaining the heat insulation performance of the refrigerator provided with a vacuum heat insulation panel between the outer box and the inner box,
  The vacuum heat insulation panel comprises a bag-shaped outer packaging material whose inside is decompressed, and a core material that is housed in the outer packaging material and has heat insulation properties,
  A first step of forming an inorganic fiber sheet by forming inorganic fiber into a sheet,
  A second step of applying a hydroxyl group treatment to the inorganic fiber sheet;
  A third step of enclosing the core material produced using the inorganic fiber sheet provided with a hydroxyl group in the outer packaging material,
  The method of maintaining the heat insulation performance of a refrigerator by adsorb | sucking the water | moisture content which the hydroxyl group provided to the said inorganic fiber sheet in the said 2nd process entered the inside of the said outer packaging material.

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