EP1200785B1 - Heat-insulating wall, such as a refrigerator housing or a refrigerator door - Google Patents

Abstract

The invention relates to a heat-insulating wall, such as a refrigerator housing (10) or a refrigerator door (13), comprising an inner jacket layer (17) and an outer jacket layer (14), these two jacket layers (14, 15) being interconnected and surrounding an intermediate chamber (17) that can be evacuated. Heat-insulating material (18) is introduced into said intermediate chamber. Said heat insulating material (18) consists of vacuum insulated components (18) which are introduced into the evacuable intermediate chamber (17) in such a way that an evacuable residual volume (21) is formed.

Description

The invention relates to a heat-insulating housing according to the preamble of claim 1. Such a housing is known for example from DE-A-196 48 305. For vacuum insulated walls, such as those proposed for refrigeration appliance housings or refrigerator doors, for example, the prior art of molding their inner and outer stainless steel sheaths has been to be 15 years in useful life in the size range for the vacuum insulation technique To reach housing and doors. Although shell layers formed from stainless steel achieve the leakage rate or permeation rate to be used for the required useful life, the shape of the cladding layers and the connection technology to be used for their construction are inherently expensive to manufacture and therefore costly. With regard to the structure of the heat-insulating walls z. B. to ensure that a heat conduction over the inner, a room with lowered temperature level bounding enveloping layer on the outer, the room temperature of the refrigerator or refrigerator door exposed shell layer is at least largely avoided. For this purpose, find membrane-like thin-walled fasteners application, which are particularly shock-sensitive due to their thinness and even with appropriate treatment, a potential source of danger in terms of leakage of the evacuated wall and are covered for this reason with additional protective elements. Moreover, it is necessary, the individual components of the heat-insulating walls, such as the inner and the outer cladding layer and serving to connect the connecting element with a connection technology guaranteeing the long-term vacuum stability of the connection, in the form of laser welding technology. However, this type of connection technology brings relatively high investment costs for the production of heat-insulating walls with it. Due to the use of stainless steel for the production of the inner and outer cladding layer, the weight of a refrigeration device housing or a refrigerator door, although thin-walled stainless steel is used for these cladding layers, also not insignificant.

The invention has for its object to propose measures based on which in a heat-insulating wall according to the preamble of claim 1 in a simple manner, the disadvantages of the prior art are avoided.

This object is achieved according to the invention by the features of claim 1.

Due to the construction according to the invention of a heat-insulating wall for use, for example, in a refrigeration appliance housing or a refrigerator door, the high demands previously placed on the tightness of such walls over their useful life are significantly reduced. This is due to the fact that the actual insulation capacity of the heat-insulating walls is provided by the vacuum-insulated components having a very low thermal conductivity, which are at the same time arranged within a likewise pressure-reduced space, whereby the pressure difference with respect to the vacuum-insulated components is reduced. By reducing the pressure difference dependent on this gas inlet into the vacuum-insulated components is substantially reduced, so that on the other hand by the combined structure and the resulting interaction of the evacuated insulation components, namely the vacuum-insulated components on the one hand and the evacuated residual volume between the outer and the inner shell layer , A production of heat-insulating walls is possible, the heat-insulating capacity corresponds at least substantially to those based on stainless steel cladding layers, heat-insulating walls. In contrast to walls provided with stainless steel cladding layers, the production of the walls according to the invention is significantly simpler and involves reduced production costs. In addition, for the production of the inner and the outer shell layer materials are used, to which lower requirements are to be made with respect to the gas and water vapor permeability and which allow for the connection of the shell layers in the production of heat-insulating walls, the use of cost-effective bonding techniques.

According to the invention, it is provided that the vacuum-insulated components consist of plate-like and / or formed as moldings vacuum insulation panels.

By using such components, a particularly homogeneous backfilling of the gap between the inner and the outer shell layer is possible, in particular by the use of adapted to the contour of the gap moldings a particularly favorable backfilling of the gap is achieved while maintaining the volume serving as a residual volume buffer volume , In particular, by providing molded parts with a material thickness corresponding to the clear distance between the inner and outer cladding layers, a high level of flatness of the heat-insulating walls results after the evacuation process of the intermediate space. The moldings may be e.g. be used as a corner element or as used in a refrigeration appliance housing coming U-shaped component for forming the housing walls application.

In a particularly simple manner, a sufficient positional stability of the inner and outer cladding layer is achieved when it is provided according to a preferred embodiment of the subject invention that the vacuum-insulated components serve as a support body for supporting the inner cladding layer and the outer cladding layer.

Particularly planar, without sinks produced, the heat-insulating walls are for use for refrigerator housings, refrigerator doors, dishwasher housing, washing machine and dryer housing, when provided for a next before ferred embodiment of the invention that the vacuum-insulated components have a material thickness which at least approximately the clear Width between the inner shell layer and the outer shell layer corresponds.

Particularly favorable, long-term stable values for the heat insulation capacity result when it is provided according to a further advantageous embodiment of the subject invention that the vacuum-insulated components are formed as introduced into an aluminum composite foil plates made of open-cell polystyrene foam or open-cell polyurethane foam or in Plate form pressed and surrounded by a gas-permeable plastic film surrounded silica are formed.

According to a further preferred embodiment of the object of the invention it is provided that the inner shell layer and / or the outer shell layer of non-deformable, thermoplastic material and / or non-deformable platinum-like, metallic material are formed.

Through the use of non-deformable, thermoplastic material can be mitanformen in a particularly simple and cost-effective manner during the deformation process, for example, a present in the form of plastic plastic in refrigerators and freezers functional parts such as Stützmaßnehnen for evaporator Etagèren, Kühlgutablagen, condensation water gutters or the like , The use of plastic materials to produce the inner and outer cladding layer significantly mitigates the problem of a thermal bridge possibly caused by the connection of the two layers, as a result of which the energy consumption of a refrigeration device is not insignificantly reduced. Furthermore, the inventive structure of the heat-insulating wall, a combination of a metallic material and a plastic envelope layer is possible, in particular by the use of metallic material for the production of the inner, the cold room of a refrigerator facing coating layer, a particularly hygienic cleaning for achieve this.

According to a preferred embodiment of the object of the invention it is provided that the inner shell layer and / or the outer shell layer is provided with reinforcing elements and / or stiffening elements, which serve to form the evacuable residual volume.

By attaching reinforcement and / or stiffening elements to the visible surfaces of the inner and / or the outer shell layer, these are also at low Wall thickness sufficiently dimensionally stable, so that even after the evacuation of the residual volume by the support of the reinforcing and / or reinforcing elements on the vacuum-insulated components an already sufficient flatness for the two cladding layers is reached. At the same time, the reinforcing and / or stiffening elements acting upon the vacuum-insulated components after the evacuation process of the residual volume cause the vacuum-insulated components to be fixed within the intermediate space.

The stiffening and / or reinforcing elements can be produced in a particularly cost-effective manner if, according to a next advantageous embodiment of the subject invention, the inner enveloping wall and / or the outer enveloping wall are at least partially shaped to serve as reinforcing and / or stiffening elements having the evacuable residual volume. In particular, in the thermoforming process without cutting deformed plastic boards for the production of the inner and / or the outer shell wall can cost-effectively targeted formations in the visible surfaces of these envelope walls bring, the shapes at the same time as functional elements, for example, for holding evaporator etagers or for supporting Kühlgutablagen or the like can be trained.

According to an alternative embodiment of the subject matter of the invention, it is provided that the evacuatable residual volume is formed by an additional volume arranged outside the evacuable intermediate space, which is fluidically coupled to the intermediate space.

This results in the ability to bring the two shell walls without stiffening and / or reinforcing measures of their support directly to the vacuum-insulated components to the plant, whereby the flatness of the shell walls directly on the flatness of the vacuum-insulated components depends, so that the flatness of the shell walls with high Precision is manageable.

Particularly favorable with regard to the maintenance of the evacuated residual volume, an inner and / or outer cladding layer herausgestellit, if it is provided according to a further preferred embodiment of the subject invention that the inner shell layer and / or outer shell layer is provided with means which at least substantially reduce the water vapor and the oxygen permeability.

Agents based on polyolefins or polyvinylidene chloride or perfluoroalkoxy polymers have proven to be particularly effective with regard to the reduction and / or even the avoidance of the water vapor permeability on the outer shell layer and / or the inner shell layer.

Particularly effective in terms of reducing or even avoiding the gas permeability to the outer shell layer and / or inner shell layer have been found by ethylene-vinyl alcohol - copolymer or by polyacrylonitrile or by polyamide formed agent.

In a particularly simple and effective manner, both the gas permeability and the water vapor permeability is avoided in an outer shell layer formed from plastic and / or in an inner shell wall formed from plastic, if it is provided according to a last, preferred embodiment of the object of the invention that the means are formed by a metal layer produced by sputtering on the outer cladding layer and / or the inner cladding layer.

In this context, in particular, a metal layer of aluminum has proven to be favorable.

The layer for reducing the water vapor and the gas permeability is applied both to the surfaces of the enveloping walls facing the gap, both in the case of the metal layer produced by sputtering and in the case of the layers specifically oriented to avoid the water vapor permeability, the gas permeability the single layer for reducing or avoiding the water vapor permeability as well as the single layer for reducing or avoiding the gas permeability by laminating or co-extruding are applied to the inner and / or outer shell layer.

The invention is explained in the following description using the example of two illustrated in the accompanying drawing simplified refrigerator housings.

Fig.1

in vereinfachter schematischer Darstellung eine erste Ausführungsform eines Kältegerätegehäuses bei geschlossener Tür mit durch Hüllschichten umgrenztem, mit vakuumisolierten Bauelementen ausgestatteten, evakuierten Zwischenraum in Schnittdarstellung von der Seite und

Fig. 2

in vereinfachter schematischer Darstellung eine zweite Ausführungsform eines Kältegerätegehäuses bei geschlossener Tür mit einem evakuierten Zwischenraum umgrenzenden, an vakuumisolierten Bauelementen anliegenden Hüllwänden, in Schnittdarstellung von der Seite.

Show it:

Fig.1

in a simplified schematic representation of a first embodiment of a refrigerator housing with the door closed with enveloped by enveloping layers, equipped with vacuum-insulated components, evacuated gap in a sectional view from the side and

Fig. 2

in a simplified schematic representation of a second embodiment of a refrigeration device housing with the door closed with an evacuated gap bounding, applied to vacuum-insulated components Hüllwänden, in section from the side.

Referring to Fig. 1 is simplified, purely schematically a suitable for use in a household refrigerator or freezer, heat-insulating housing 10 is shown, the heat insulation is based on vacuum insulation technology. The heat-insulating housing 10 has a usable space designed as a cold room 11 and is equipped to close its working space 11 with a resiliently over a magnetic seal 12 at its opening edge door 13. The door 13 and the housing 10 are vacuum-insulated based on the same technique and have a wall construction serving to achieve their heat-insulating effect. The wall structure of the door 13 has in the present embodiment, a non-cutting thermoplastic, for example, thermoforming molded, one-piece outer panel 14, which is used for their attachment to the door 13 for fixing a door handle, not shown, and which on the housing 10 to form its outer shell or outer shell layer is provided. Spaced apart from the outer lining 14, the wall construction used for the door 13 and the housing 10 in the present case also has a one-piece inner lining 15 which is formed without cutting, for example by thermoforming of thermoplastic material, which in the present case already has stiffening elements 16 introduced during its production process has stiffening ribs or stiffening beads, which faces with its free end of the outer lining are. Both the outer lining 14 and the inner lining 15 are made for example of schtagzähem polystyrene having a material thickness of 0.8 to 2.0 mm and have a layered structure, which in addition to the thermoplastic material, a layer for reducing or even inhibiting the gas permeability and a Layer for reducing or even inhibiting the water vapor permeability, wherein the water vapor permeability counteracting layer is applied, for example by coextrusion or lamination and formed on the basis of polyols such as high density polyethylene, or polypropylene or other materials such as polyvinylidene chloride or perfluoroalkoxypolymere. The layer following this, the gas permeability counteracting layer is also applied by coextrusion or lamination on the thermoplastic material and consists for example of ethylene-phenyl alcohol copolymer or polyacrylonitrile or polyamide. In combination with the made of polystyrene outer lining 14 and the inner lining 15 has a the gas permeability counteracting or gas permeability inhibiting layer of ethylene-phenyl alcohol copolymer having a layer thickness of about 470 microns and serving as a water vapor barrier layer of perfluoroalkoxy with a layer thickness proven of 30 - 35 μm. The outer cladding 14 or inner cladding 15 provided with the layers are connected to one another vacuum-tight at their free end by welding, gluing or the like and in the present case enclose an evacuatable intermediate space 17. In these vacuum-insulated components 18 are introduced, which serve as vacuum insulation. Panels are formed. The plate-shaped, vacuum-insulated components 18 have an example of open-cell polystyrene foam, or open-cell polyurethane foam or formed from silica support body 19 which is disposed within a vacuum-tight enclosure 20 which rests in the evacuated state on the surface of the support body 19 and which formed in the case of an open-cell polyurethane foam or an open-cell polystyrene foam support body of an aluminum composite film of the trade name "Toyo" and in addition to a layer of polyethylene, aluminum, a metallized layer of polyethylene terephthalate also has a layer of polyamide, whereby both a water vapor and a gas barrier is generated. In the event that silica is used for the supporting body 19, its vacuum-tight covering, for example formed from a plastic film, is to pay attention mainly to a barrier against gas permeability. because the silica itself acts as a getter for water vapor. The introduced into the gap 17, vacuum-insulated components 18 are with their enclosure 20 on the free, projecting into the gap 17 ends of the stiffening elements 16, whereby within the gap 17 an evacuable residual volume 21 is formed, through which after his Evakuiervorgang a significantly reduced Pressure difference between the vacuum-insulated devices 18 and the gap 17 is generated, whereby the dependent of this pressure difference, contributing to the reduction of the heat insulating ability gas passage to the vacuum-insulated devices 18 is significantly reduced.

Fig. 2 shows a simplified schematic representation of a second embodiment of a heat insulating insulating vacuum-based housing 30, which accommodates at least one cold room 31, which is accessible via a resiliently based on a magnetic seal 32 at the opening edge of the housing door 33. Both the door 33 and the housing 30 are based on identical thermal insulation technology and also have an identical wall structure, so that in the following description for the Wandüngsaufbau the door 33 and those used for the housing 30 components are denoted by identical Bezugsziffem , To achieve the thermal insulation for the door 33 and the housing 30 both have a thermoplastic material, for example by deep drawing non-cutting molded one-piece outer panel 34, which serves in the case of the door 33 for fixing a door handle, not shown, while the outer panel 34 for their use on Housing 30 whose outer sheath or outer cladding layer forms. In contrast to the door 33, the outer panel is in the case of its application as an outer jacket for the housing 30 with a, for example, directly to the outer panel with molded, serving as a residual volume 35 additional volume.

At a distance to the outer lining 34, both the door 33 and the housing 30 has a likewise made of thermoplastic material spanlos z. B. formed by thermoforming, one-piece interior trim 36 or inner shell layer, which is provided in the case of the housing 30 for lining the cold room 31 and which faces the cold room 31 for their use on the door 33.

In contrast to the housing 30 used for the inner lining 36, an additional volume serving as a residual volume 37, which projects into the cold room 31 in the present exemplary embodiment, is also formed on the inner lining 36 of the door 33. Both the inner panel 36 and the outer panel 34 is constructed in both cases, namely for the door 33 and the housing 30 with respect to their wall structure identical to the inner panel 15 and outer panel 14 used for the door 13 and the housing 10. The outer panel 34 and the inner panel 36 are vacuum-tight at their free ends such as the outer panel 14 and the inner panel 15 by joining techniques such as welding, gluing or the like and enclose an evacuable gap 38, in which vacuum-insulated components 39 in the form of so-called vacuum Insulation panels are introduced, which like the vacuum-insulated components 18 have a plate-like support body 40 and a vacuum-tight surrounding the support body 40 casing 41, wherein for the support body 40 and its cover 41 materials are used, which are identical to those for the components 18th for use coming support body 19 and the sheath 20 are formed. The vacuum-insulated components 39 are matched in the present embodiment in terms of their strength to the inside width of the gap 38, so that the vacuum-insulated components 39 after the evacuation of the vacuum-tight, enclosed by the inner lining 36 and the outer lining 34 space 38 for supporting the inner lining 36 and the Outer lining serve 34, which are generated for both the door 33 and the housing 30 at least largely flat viewing surfaces. After the evacuation operation of the intermediate space 38, both in the case of the housing 30 and in the case of the door 33, the additional volumes 35 or 37 fluidically coupled to the intermediate space 38, as in the case 10 or the door 13, reduce the pressure difference between the vacuum-insulated ones Components 39 and the gap 38 generated, whereby the heat-insulating effect of the door 33 and the housing 30 narrowing gas passage to the vacuum-insulating components 39 is significantly reduced. Here, the additional volumes serve 35 and 37 as a buffer to maintain a reduced pressure difference between the gap 38 and the vacuum-insulating components 39 for long-term stable maintenance of the heat insulating capacity of the door 33 and the housing 30th

Contrary to the two described embodiments can be brought by suppression of water vapor and gas permeability for both the outer panels 14 and 34 and for the inner lining 15 and 36, a layer of aluminum produced by Aufsputtem for application. Furthermore, it is also possible to produce either the outer linings 14 and 34 and the inner linings 15 and 36 made of stainless steel, or to provide a combination of the two materials for the production of the housing and the door, where it is expedient for reasons of hygiene to design the interior linings of stainless steel.

Claims (12)

1. Thermal insulating housing, such as a refrigerating appliance housing (10, 30) or a refrigerating appliance door (13, 33), a dishwashing machine housing, a washing machine or laundry drier housing or the like, with an inner encasing layer (15, 36) and an outer encasing layer (14, 34), wherein the two encasing layers are connected together and enclose an evacuated intermediate space (17, 38), into which thermal insulation material (18, 39) is introduced, wherein the thermal insulation material is formed from vacuum-insulated components (18, 39) which are introduced to form an evacuatable residual volume (21, 35), into the evacuatable intermediate space (17, 38) characterised in that the vacuum-insulated components (18, 39) consist of vacuum insulation panels which are plate-like and/or constructed as moulded parts.
2. Thermal insulating wall according to claim 1, characterised in that the vacuum-insulated components (18, 39) serve as support bodies for supporting the inner encasing layer (15, 36) and the outer encasing layer (14, 34).
3. Thermal insulating wall according to one of claims 1 and 2, characterised in that the vacuum-insulated components (39) have a material thickness which corresponds at least approximately with the clear width between the inner encasing layer (36) and the outer encasing layer (34).
4. Thermal insulating wall according to one of claims 1 to 3, characterised in that the vacuum-insulated components (18, 39) are formed as plates, which are vacuum-tightly incorporated in an aluminium composite foil, of open-cell polystyrol foam or open-cell polyurethane foam or are constructed as silica plates vacuum-tightly incorporated in a synthetic material foil serving as a gas barrier.
5. Thermal insulating wall according to one of claims 1 to 4, characterised in that the inner encasing layer (15, 36 and/or the outer encasing layer (14, 34) are formed from a thermoplastic synthetic material deformable without cutting and/or from plate-shaped metallic materials deformable without cutting.
6. Thermal insulating wall according to one of claims 1 to 5, characterised in that the inner encasing layer (15) and/or the outer encasing layer (14) is or are provided with reinforcing and/or stiffening elements serving for formation of the residual volume (21).
7. Thermal insulating wall according to one of claims 1 to 6, characterised in that the inner encasing layer (15) and/or the outer encasing layer (14) have at least partial shapes, which serve as stiffening and/or reinforcing elements (16), for formation of the evacuatable residual volume (21).
8. Thermal insulating wall according to one of claims 1 to 7, characterised in that the evacuatable residual volume (37) is formed by an additional volume which is arranged outside the evacuatable intermediate space (38) and which is coupled to the intermediate space (38) in terms of flow.
9. Thermal insulating wall according to one of claims 1 to 8, characterised in that the inner encasing layer (15, 36) and/or the outer encasing layer (14, 34) is or are provided with means which at least substantially reduce permeability to water steam and oxygen.
10. Thermal insulating wall according to claim 9, characterised in that the means for at least substantial reduction in the water steam permeability at the outer encasing layer (14, 34) and/or the inner encasing layer (15, 36) are formed by polyolefines or by polyvinylidene chloride or by perfluoralkoxy polymers.
11. Thermal insulating wall according to claim 9, characterised in that the means for at least substantial reduction in the oxygen permeability of the outer encasing layer (14, 34) and/or the inner encasing layer (15, 36) are formed by ethylenevinylalcohol copolymerisate or by polyacrylnitrile or polyamide.
12. Thermal insulating wall according to claim 9, characterised in that the means for at least substantial reduction in the oxygen permeability are formed by an aluminium coating produced through sputtering on the outer encasing layer (14, 34) and/or the inner encasing layer (15, 36).

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