ES2895482T3 - thermoregulated container - Google Patents

Abstract

Thermoregulated container in the form of a cabinet or chest, with an internal space (100) that is cooled or heated, and a thermoelectric element (20), in particular with a Peltier element that is arranged in such a way that the internal space (100) is cooled or heated. heated by the thermoelectric element (20), where several thermoelectric elements (20) are present for the thermoregulation of the internal space (100), which are arranged spatially spaced apart from each other, the container has main surfaces that, in the case of a cabinet-shaped container, they comprise the two side walls, the top wall, the base and the rear wall, and in the case of a chest-shaped container they comprise the two side walls, the front wall, the rear wall and the back wall. base, two of the thermoelectric elements (20) are arranged on different main surfaces, and the outer shell (A) and the inner wall (I) of the container, which delimit to the internal space (100), they are completely composed of a metal plate, characterized in that the internal wall (I) that delimits the internal space (100) has a smaller wall thickness than the external cover (A) of the container .

Description

DESCRIPTION

thermoregulated container

Different concepts for cooling in refrigerating or deep-freezing appliances are known from the state of the art. In all cases, for the highest possible degree of effectiveness and thus for good energy efficiency, an effective heat exchanger is necessary, both on the cooling space side and on the waste heat side, in order to maintain as low as possible the temperature rise to be overcome. In this context, the coupling to the refrigeration area and the cooling space, as well as to the external air, into which the dissipated heat is released, is important.

An essential parameter in the case of a required cooling capacity of a refrigerating or freezing appliance consists of the thermal insulation surrounding the internal refrigerated space. If the thermal insulation is improved, the demand for cooling power is reduced. In the case of a low cooling demand, simpler means can be provided than in compression cooling machines, indeed, in particular by means of a thermoelectric element. For example, the use of a Peltier element is known. Thus, for example, a refrigerator insulated by vacuum insulation needs only a cooling power of 3-4 W, which can be applied, for example, by a thermoelectric element.

In the case of the use of Peltier elements, a particularity resides in the fact that the generated cooling power and waste heat are produced in direct spatial proximity - no coolant is present as heat carrier. In this case, heat transfer to the internal refrigerated space, as well as to the external air, towards which the heat is dissipated, is particularly important. It is known from the state of the art to improve this heat transfer in Peltier cooling devices, such as portable refrigerators, by means of finned heat exchangers and by means of air circulation produced by means of fans. Its power demand is in an order of magnitude similar to that of the Peltier element.

These considerations, however, are by no means limited to refrigeration and/or freezing appliances, but rather apply to thermally insulated containers in general, where the thermally insulated containers covered by these considerations have at least one thermoregulated internal space , which can be cooled or heated, so that the internal space results in a temperature below or above the ambient temperature, for example 21°C.

Documents US5715684, EP0592044, US5653111, DE111322, GB2331838, CN1307215, US6412286 and JPH08110154 describe refrigeration and/or freezing appliances with at least one thermoelectric element. The object of the present invention is to perfect a thermoregulated container of the kind mentioned in the introduction, in the sense that the best possible dissipation of the heat generated towards the internal thermoregulated space is achieved, with the aim of heating or maintaining it. temperature, or towards the outside, with the aim of cooling the internal space.

Said object is solved by means of a thermoregulated container with the characteristics of claim 1. The present invention is described in independent claim 1. Other exemplary embodiments are described in the dependent claims.

Accordingly, provision is made for several thermoelectric elements to be present for temperature regulation of the internal space of the container, which are arranged spatially spaced apart from one another.

The present invention is based on the idea of not only using a single thermoelectric element for the thermoregulation of the cooled internal space, but at least two thermoelectric elements. Thanks to this, an improved thermoregulation (heating or cooling) of the internal space can be effected, since in the case of cooling of the internal space the residual heat can be well distributed on the outer shell of the appliance, and in the case of heating it can be well distributed on the wall that delimits the internal space.

Furthermore, the use of several thermoelectric elements that are arranged at a spatial distance provides the possibility of specific temperature regulation of different areas of the internal space, so that different cooling/heating powers can be made available there at different points.

According to the invention it is provided that the container has main surfaces and that at least two of the thermoelectric elements are arranged on different main surfaces. "Major surfaces", in the case of a cabinet-shaped container, means the two side walls, the top wall, the base and the bottom wall. back, and in the case of a chest-shaped container the two side walls, the front wall, the back wall and the base.

It is possible that at least one thermoelectric element is arranged on each of the main surfaces or on a part of the main surfaces respectively. For example, in the case of a cabinet-shaped container it is possible that at least one thermoelectric element is arranged on the side walls, on the base and on the top wall in each case.

Alternatively or additionally, it can be provided that one or more elements are arranged on the closing element (door, cover, lid, drawer front, etc.), by means of which the temperature-regulated internal space can be closed. thermoelectrics.

In another embodiment of the invention, it is provided that each of the thermoelectric elements, both on the cold side and on the hot side, is in each case connected with thermal conduction to a passively working primary heat exchanger. By a passively working heat exchanger is meant an element that conducts or otherwise transfers heat to or from the thermoelectric element, without requiring a power supply to do so.

It is possible for the primary heat exchanger to be made up of a metallic body, preferably aluminum or containing metal, in particular aluminium. The metallic bodies are thus connected to the cold side and the hot side of the thermoelectric element, and conduct heat to the thermoelectric element and dissipate heat from the thermoelectric element.

For residual heat coupling, i.e. for heat transfer without high temperature gradients, it is considered advantageous that the primary heat exchanger(s) have a cross-sectional area that increases with increasing distance from the thermoelectric element, so that the heat or waste heat is distributed over a larger surface

It is considered especially advantageous that the thermoelectric element or elements are arranged in such a way that they are connected with thermal transfer or with thermal conduction of another kind, to the external cover and to the internal wall of the container, which delimits the internal space, in such a way that the outer shell and the inner wall are used as secondary heat exchangers.

The outer shell of the container and the inner wall of the container, which delimits the internal space, together are made of metal, where the metal is preferably aluminum.

If primary and secondary heat exchangers are provided, these are connected to one another with direct or indirect heat transfer, in particular with heat conduction. According to the invention it is envisaged that the external shell and the internal wall of the container, which delimits the internal space, consist entirely of a metal plate.

In this case, it is preferably provided that the plate has a thickness of <3 mm, preferably a thickness of 1 to 2 mm.

If the thermoregulated container is a refrigeration or freezing appliance, for the distribution of residual heat in the complete external cover of the appliance, it is enough that it is structured on the basis of an aluminum plate with a thickness of 1 to 2 mm. . That outer covering can be found on each side of the body or only on part of the sides of the body.

Since the amount of cold that is produced is less than the residual heat, inside the apparatus, ie in the internal space, such high demands are not placed on the heat exchanger. However, it is also planned to manufacture the internal container, that is to say the wall that delimits the internal space, from a metal plate, and preferably from an aluminum plate, where a smaller thickness of the plate is used for this than for the external coating.

The container can be made like a cabinet and can have a back wall, two side walls, a lid and a base, or in the case of a chest it can have two side walls, a back wall, a base and a front wall. . At least one thermoelectric element is arranged in each or at least two of the mentioned walls.

As explained above, the container can have a closing element, such as a door, a lid or the like, and at least one thermoelectric element can be arranged in the closing element.

In another embodiment of the invention, provision is made for different temperature zones to exist in the internal space. In this way, for example, different temperatures can be provided, where in one zone the usual temperature of a conventional cooling compartment may be present and in another zone the usual temperature of a cooling drawer may be present.

For example, this can be achieved by separate activation of the individual thermoelectric elements.

Such separate activation can not only be used to provide different temperature areas within the cooled or heated internal space, but also in the event of a particularly high heat input in one area of the internal space, for example due to the placement of products that must be be cooled or frozen, in order to generate a particularly high cooling capacity there. This applies correspondingly for the reverse case of a heated container.

In this way, at least one control or regulation unit can be provided that activates the plurality of thermoelectric elements all in the same way or in a different way, so that they generate identical or different power from each other.

Particular preference is given to an embodiment in which a thermal insulation consisting of a completely vacuum system is arranged between the inner wall delimiting the inner space and the inner wall. By this can be understood a thermal insulation that exclusively or mainly consists of a hollow area, which is filled with a core material. The delimitation of this area, for example, can be formed by a vacuum-tight sheet and preferably by a high-barrier sheet. In this way, between the inner wall of the device and the outer wall, as thermal insulation, exclusively such a foil body can be present, which has an area surrounded by a vacuum-tight foil, in which the vacuum predominates and in which a core material is disposed. Preferably, between the inner side and the outer side of the container, except for the completely vacuum system, a foamed material and/or vacuum insulation panels are not provided as thermal insulation or other thermal insulation.

This preferred form of thermal insulation in the form of a completely vacuum system can extend between the wall that delimits the internal space and the external lining of the body and/or between the internal and external sides of the closing element, such as a door, cover, lid or the like.

The completely vacuum system can be achieved in that an envelope, based on a gas-tight foil, is filled with a core material and then sealed in a vacuum-tight manner. In one embodiment, both the filling and the gas-tight sealing of the casing take place at normal pressure or ambient pressure. Evacuation then takes place by connecting an interface, incorporated in the casing, for example an evacuation sleeve, which may have a valve, to a vacuum pump. Preferably, during evacuation, outside the casing, normal pressure or ambient pressure prevails. In this embodiment, at no time during manufacture is it necessary to place the casing in a vacuum chamber. In this sense, in one embodiment, a vacuum chamber can be dispensed with during the production of the vacuum insulation.

By a vacuum-tight or diffusion-tight casing, as well as a vacuum-tight or diffusion-tight connection, as well as the term high-barrier foil, it is preferably meant a casing, a connection or a foil by means of which the gas ingress into the vacuum insulating body is so small that the increase in thermal conductivity of the vacuum insulating body caused by gas ingress is sufficiently small over its service life. As a service life, for example, a period of 15 years, preferably 20 years and especially preferably 30 years. Preferably, the increase in conductivity of the vacuum insulating body during its service life, caused by gas ingress, is <100%, and particularly preferably <50%.

Preferably, the gas flow rate of the casing, as well as of the connection, as well as of the high-barrier foil, is < 10-5 mbar * I / s *m2 and is particularly preferably < 10-6 mbar * I / s *m2 (measured according to ASTM D-3985). This rate of gas passage applies to nitrogen and oxygen. For other types of gases (particularly water vapour), there are also low gas flow rates, preferably in the range of < 10-2 mbar * l / s * m2 and particularly preferably < 10-3 mbar * I / s * m2 (measured according to ASTM F-1249 90). Preferably, due to these low gas flow rates, the aforementioned low increases in thermal conductivity are achieved.

A well-known wrapping system from the vacuum panel area is so-called high-barrier foils. In the context of the present invention, these are preferably understood as single-layer or multi-layer (preferably sealable) films with one or more barrier layers (usually metal layers or oxide layers, where metal or oxide is preferably uses aluminum, or an aluminum oxide), which they meet the aforementioned requirements (increased thermal conductivity and/or specific gas passage index of the surface), as a barrier against gas ingress.

The aforementioned values, as well as the structure of the high-barrier film, are preferred data, by way of example, which do not limit the invention.

Preferably, the container according to the invention is a refrigerating and/or freezing apparatus, the internal space of which is cooled by thermoelectric elements. However, the invention also covers the case of a container whose internal space is heated by thermoelectric elements. The thermoregulated internal space is cooled or heated, depending on the type of appliance (refrigeration appliance, heating cabinet).

The refrigeration and/or freezing device can be, for example, a domestic appliance or an industrial refrigeration appliance. For example, those devices that are designed for a fixed arrangement in the home, in a hotel room, in an industrial kitchen or in a bar are considered. For example, it can also be a wine cooler. The invention also encompasses refrigeration and/or freezer cabinets. The devices according to the invention can have an interface for connection to a power supply, in particular to a domestic electrical network (for example a connector), and/or an auxiliary support or installation element, such as legs. retractable, or an interface for fixing within a cavity of a piece of furniture. For example, the device can be a built-in device or also a floor-mounted device.

In one embodiment, the container or the appliance is designed in such a way that it can be operated with an alternating voltage, such as a household mains voltage of for example 120 V and 60 Hz, or 230 V and 50 Hz. Hz. In an alternative embodiment, the container, as well as the apparatus, are designed in such a way that it can operate with a direct current of a voltage of, for example, 5 V, 12 V or 24 V. In this configuration, provision can be made for inside or outside the apparatus a mains adapter unit is provided, by means of which the apparatus functions. An advantage of using thermoelectric heat pumps in this embodiment lies in the fact that the problem of electromagnetic compatibility (EMC) occurs only in the supply unit.

In particular, provision can be made for the cooling and/or freezing appliance to have a cabinet-like shape and a usable space that can be accessed by a user, on its front side (in the case of a chest, on the top side). The useful space can be divided into several compartments that all work at the same temperature or at different temperatures. Alternatively only one compartment may be provided. Within the useful space, as well as within a compartment, auxiliary elements for support can also be provided, such as support shelves, drawers or bottle holders (in the case of a chest also dividers), to ensure optimal storage of products to be refrigerated or frozen and optimal use of space.

The useful space can be closed by at least one door that can pivot around a vertical axis. In the case of a chest, a lid that can pivot about a horizontal axis, or a sliding lid, is possible as a closing element. The door or other closing element, in the closed state, can be connected to the body essentially air-tight by means of a continuous magnetic seal. Preferably, also the doors or other closing element are thermally insulated, where the thermal insulation can be achieved by means of a foam material and optionally by means of vacuum insulation panels, or also, preferably, by means of a vacuum system, and especially preferably, by means of a completely vacuum system. Door shelves can optionally be provided on the inner side of the doors, so that products to be refrigerated can also be stored there.

In one embodiment, it may be a small device. In apparatus of this kind, the useful space, which is defined by the internal wall of the container, has, for example, a volume of less than 0.5 m3, less than 0.4 m3 or less than 0.3 m3

The external dimensions of the container or apparatus are preferably in the range of up to 1 m, with respect to height, width and depth.

However, the invention is not limited to refrigerating and/or freezing appliances, but relates generally to appliances with a thermoregulated internal space, for example also to heating cabinets or heating chests.

Other features and advantages of the invention are explained in detail by means of an exemplary embodiment shown in the drawing. The single figure shows a longitudinal sectional view through a refrigerating and/or freezing apparatus according to the invention.

In Figure 1, the reference symbol 10 identifies the body of a refrigerating and/or freezing appliance in the form of a cabinet.

The body 10 has two side walls 12, a cover 14 and a base 16. Together with the rear wall and a door, these define the internal refrigerated space 100 .

As can be seen in the figure, a thermoelectric element 20 is provided on the two side walls 12, on the cover wall 14 and on the base 16 respectively.

In principle, just such a thermoelectric element can be provided per wall. However, the invention also covers the case where two or more than two thermoelectric elements are present in one or more walls.

Arrangement of one or more thermoelectric elements on the rear of the device is also possible and is covered by the invention.

Each of the thermoelectric elements 20, both on the cold side, facing the internal space 100, and also on the hot side, facing the outside, is in each case connected with heat transfer to a primary heat exchanger 30, 40 , in particular with thermal conduction. These primary heat exchangers 30, 40 are made of metallic bodies, for example aluminum.

During the operation of the thermoelectric elements 20, through their cold side and through the heat exchanger 30 and the inner wall I, heat is extracted from the cooled internal space. The heat, through the hot side of the thermoelectric element 20, the heat exchanger 40 and the external wall A, is dissipated towards the environment.

As can be seen further in Figure 1, the cross section of the primary heat exchangers 30, 40 enlarges starting from the thermoelectric element 20 towards the external wall A, as well as towards the internal wall I, which together with the internal side of the door delimits the refrigerated internal space 100. In this way, the residual heat that is extracted from the internal space 100 by the thermoelectric elements 20 can be distributed over a larger surface without a higher temperature gradient.

The external side of the apparatus is formed by the external wall A, which as a whole consists of a metal plate, preferably an aluminum plate.

In the exemplary embodiment shown here, this plate forms the outer side A of the side walls 12 of the lid 14, as well as of the base 16. The outer side and/or the door can also be made correspondingly, on the external side.

The outer wall-forming plate A forms the secondary heat exchanger which is connected with heat transfer to the primary heat exchangers 40, in particular with heat conduction.

The internal wall I is also formed by a metal plate, in particular by an aluminum plate. The inner wall I is connected with thermal transfer to the primary heat exchangers 30, in particular with thermal conduction.

The term "heat exchanger", according to the present invention, covers any element that is suitable for the transfer of heat. According to the invention, the heat exchangers are made up of metallic bodies.

Reference symbol 50 identifies the thermal insulation that extends between the internal wall I and the external wall A of the body. This thermal insulation is made up of a volume delimited by one or more vacuum-tight sheets, in which there is a core material, in particular perlite. Preferably, no other insulation materials, such as foam and/or vacuum insulation boards, are provided between the inner wall I and the outer wall A.

Furthermore, a corresponding completely vacuum thermal insulation can be provided for the door or for another closing element.

The Peltier elements 20 or the other thermoelectric elements are distributed in such a way over the geometry of the device that their residual heat is distributed as best as possible on the external cover A of the device. For the distribution of residual heat over the entire external cover A, it can be structured on the basis of an aluminum plate with a thickness of 1 to 2 mm.

Since the amount of cold produced is less than the residual heat, within the apparatus 100 such high demands are not placed on the heat exchanger. According to the invention, however, a plate (for example an aluminum plate) is also used for the internal wall of the appliance, which has a smaller thickness than the plate forming the external cover A.

As explained above, by separate activation of the thermoelectric elements 20, a cooling and/or freezing device can be realized, as well as a heated container, in which different temperature zones predominate. In principle, however, the invention also covers the case where exactly one temperature prevails in the cooled or heated internal space 100 .

Depending on the interconnection of the thermoelectric elements, these can heat or cool the internal space, so that the container according to the invention can be used for both purposes. In this way, the container can perform a heat maintenance function. The exemplary embodiment thus also applies to a heated container with reverse activated thermoelectric elements 20, in which the hot side is inside and the cold side is outside.

If the container is not required for heating, the same container can be used for cooling by appropriate activation of the thermoelectric elements.

Preferably, exclusively thermoelectric elements are used for the thermoregulation of the cooled internal space.

Claims (10)

1. Thermoregulated container in the form of a cabinet or chest, with an internal space (100) cooled or heated, and a thermoelectric element (20), in particular with a Peltier element that is arranged in such a way that the internal space (100) is cools or heats by means of the thermoelectric element (20), where for the thermoregulation of the internal space (100) several thermoelectric elements (20) are present that are spatially spaced apart from each other, the container has main surfaces that, in the In the case of a cabinet-shaped container, they comprise the two side walls, the top wall, the base and the rear wall, and in the case of a chest-shaped container they comprise the two side walls, the front wall, the rear wall. and the base, two of the thermoelectric elements (20) are arranged on different main surfaces, and the outer shell (A) and the inner wall (I) of the container, which deli limit the internal space (100), they are completely composed of a metal plate, characterized in that the internal wall (I) that delimits the internal space (100) has a smaller wall thickness than the external cover (A) of the container . Container according to claim 1, characterized in that each of the thermoelectric elements (20), both on the cold side and on the hot side, is in each case connected with thermal conduction to a primary heat exchanger (30, 40) that works passively. Container according to claim 2, characterized in that each of the two primary heat exchangers (30, 40) is made up of a metallic body or has the same, where the metal is preferably aluminium. Container according to claim 2 or 3, characterized in that the primary heat exchangers (30, 40) have a cross-sectional area that increases with increasing distance from the thermoelectric element (20). Container according to one of the preceding claims, characterized in that the thermoelectric elements (20) are arranged in such a way that they are connected with heat transfer, in particular with heat conduction, to the outer shell (A) and to the inner wall ( I) of the container, which delimits the internal space (100), so that the external cover (A) and the internal wall (I) are used as secondary heat exchangers. Container according to one of the preceding claims, characterized in that the container has a closing element, such as a door, a lid or the like, and at least one thermoelectric element (20) is arranged on the closing element. Container according to one of the preceding claims, characterized in that different temperature zones exist in the internal space (100). Container according to one of the preceding claims, characterized in that a control or regulation unit is provided which activates the entire plurality of thermoelectric elements (20) in the same way or differently. Container according to one of the preceding claims, characterized in that between the internal wall (I) delimiting the internal space (100) and the external wall (A) there is a thermal insulation that in its entirety or in some sections consists of a completely vacuum system (50). Container according to one of the preceding claims, characterized in that the container is a refrigerating and/or freezing device.