EP3155329B1 - Tempered container - Google Patents

Description

Different concepts for generating cold in refrigerators and freezers are known from the prior art. In all cases, an effective heat exchanger is necessary both on the cold room side and on the waste heat side in order to achieve the greatest possible degree of efficiency and thus good energy efficiency in order to keep the temperature lift to be overcome as low as possible. In this context, the coupling to the area of Cold generation and to the cold room as well as to the outside air, to which the dissipated heat is given off.

An essential parameter for the required cooling capacity of a refrigerator or freezer is the thermal insulation that surrounds the cooled interior. If the thermal insulation is improved, the need for cooling capacity is reduced. In the case of a low cooling requirement, the provision can be made by simpler means than by compression refrigeration machines, namely in particular by means of a thermoelectric element. The use of a Peltier element is known, for example. For example, a small refrigerator insulated by vacuum insulation only needs a cooling capacity of 3 - 4 W, which can be applied, for example, by a thermoelectric element.

A special feature of the use of Peltier elements is that the generated cooling capacity and the waste heat occur in the immediate vicinity - there is no refrigerant as a heat transfer medium. In this case, the heat transfer to the cooled interior and to the outside air to which the heat is given off is of particular importance. It is known from the prior art to improve this heat transfer in Peltier cooling devices, such as, for example, portable cool boxes, by means of fin heat exchangers and by means of an air flow generated by fans. Their power requirement is of a similar order of magnitude as that of the Peltier element.

However, these considerations are by no means limited to refrigerators and / or freezers but apply to heat-insulated containers in general, with heat-insulated containers covered by these considerations having at least one temperature-controlled interior space, which can be cooled or heated, so that the temperature in the interior space is below or above the ambient temperature of 21 ° C, for example.

Documents US5715684 , EP0592044 , US5653111 , DE111322 , GB2331838 , CN1307215 , US6412286 and JPH08110154 disclose refrigerators and / or freezers with at least one thermoelectric element.

The present invention is based on the object of developing a temperature-controlled container of the type mentioned in such a way that the best possible dissipation of the generated heat into the temperature-controlled interior for the purpose of heating or keeping it warm or to the outside for the purpose of cooling the interior is achieved.

This object is achieved by a temperature-controlled container with the features of claim 1.

The present invention is disclosed in independent claim 1. Further embodiments are disclosed in the dependent claims.

According to this, it is provided that several thermoelectric elements are present for temperature control of the interior of the container, which are arranged at a spatial distance from one another.

The present invention is thus based on the idea of using not just a single thermoelectric element, but at least two thermoelectric elements, to control the temperature of the cooled interior. This allows improved temperature control (heating or cooling) of the interior, since the waste heat in the case of cooling the interior can be distributed well to the outer skin of the device and, in the case of heating, can be well distributed over the wall delimiting the interior.

In addition, the use of several thermoelectric elements, which are arranged spatially distributed, offers the possibility of targeted temperature control of different areas of the interior, so that different cooling / heating capacities 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. In the case of a cabinet-shaped container, “main surfaces” are understood to mean the two side walls, the top wall, the base and the rear wall and, in the case of a chest-shaped container, the two side walls, the front wall, the rear wall and the base.

It is conceivable that at least one thermoelectric element is arranged in each of the main surfaces or in some of the main surfaces. In the case of a cabinet-shaped container, for example, it is conceivable for at least one thermoelectric element each to be arranged in the side walls, in the base and in the top wall.

As an alternative or in addition to this, it can be provided that one or more thermoelectric elements are arranged in the closure element (door, lid, flap, front of a drawer, etc.) by means of which the temperature-controlled interior can be closed.

In a further embodiment of the invention it is provided that each of the thermoelectric elements are in a thermally conductive connection both on the cold side and on the warm side with one passively operating primary heat exchanger. A passively operating heat exchanger is to be understood as an element that conducts or otherwise transfers heat from or to the thermoelectric element without the need for an energy supply.

It is conceivable that the primary heat exchanger consists of a metallic body, preferably aluminum, or metal, in particular aluminum having. The metal bodies are thus in connection with the cold and with the warm side of the thermoelectric element and conduct heat to the thermoelectric element and heat away from the thermoelectric element.

For coupling the waste heat, ie for transferring the heat without a large temperature gradient, it is advantageous if the primary heat exchanger or heat exchangers have a cross-sectional area that increases with increasing distance from the thermoelectric element, so that the heat or waste heat over a larger area is distributed.

It is particularly advantageous if the thermoelectric element or elements are arranged in such a way that they are thermally conductive or otherwise heat-transferring with the outer skin and with the inner wall of the container delimiting the interior space, so that the outer skin and the inner wall serve as secondary heat exchangers.

The outer skin of the container and the inner wall of the container delimiting the interior space consist entirely of metal, the metal preferably being aluminum.

If primary and secondary heat exchangers are provided, they are directly or indirectly connected to one another to transfer heat, in particular to conduct heat. According to the invention it is provided that the outer skin and the inner wall of the container delimiting the interior are made entirely from one Consist of sheet metal.

It is preferably provided that the sheet metal has a thickness of <3 mm, preferably a thickness of 1 to 2 mm.

If the temperature-controlled container is a refrigerator or freezer, it is sufficient to distribute the waste heat over the entire outer skin of the device if it is made of an aluminum sheet with a thickness of 1 to 2 mm. This outer skin can be on each side of the body or only on a part of the body sides.

Since the amount of cold that accumulates is less than the waste heat, there are no such high demands on the heat exchanger inside the device, i.e. in the interior. Nevertheless, it is provided that the inner container, i.e. the wall delimiting the interior space, is also manufactured from a metal sheet and preferably from an aluminum sheet, with a smaller sheet thickness being used for this than for the outer shell.

The container can be designed like a cabinet and have a rear wall, two side walls, a ceiling and a floor or, in the case of a chest, two side walls, a rear wall, a floor and a front wall. At least one thermoelectric element is arranged in each or in at least two of the walls mentioned.

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

In a further embodiment of the invention it is provided that different temperature zones exist in the interior. For example Cooling zones of different temperatures can be provided, the usual temperature of a conventional cooling compartment in one zone and the usual temperature of a cold storage compartment in another zone.

This can be achieved, for example, by separately controlling the individual thermoelectric elements.

This separate control can not only be used to provide areas of different temperatures within the cooled or heated interior, but also in the case of a particularly large heat input in an area of the interior, e.g. through the insertion of chilled or frozen goods, a particularly high cooling capacity there to create. The same applies to the reverse case of a heated container.

Thus, at least one control or regulation unit can be provided which controls the plurality of thermoelectric elements all identically or differently, so that they provide identical or different services.

Particularly preferred is an embodiment in which a thermal insulation is arranged between the inner wall delimiting the interior space and the outer wall, which insulation consists of a full vacuum system. This is understood to mean thermal insulation that consists exclusively or predominantly of an evacuated area that is filled with a core material. The delimitation of this area can be formed, for example, by a vacuum-tight film and preferably by a high-barrier film. Thus, between the inner wall of the device and the outer wall, only such a film body can be present as thermal insulation, which has an area surrounded by a vacuum-tight film, in which there is a vacuum and in which a core material is arranged. One Foam and / or vacuum insulation panels as thermal insulation or any other thermal insulation apart from the full vacuum system between the inside and the outside of the container are preferably not provided.

This preferred type of thermal insulation in the form of a full vacuum system can extend between the wall delimiting the interior space and the outer shell of the body and / or between the inside and the outside of the closure element, such as a door, flap, lid or the like.

The full vacuum system can be obtained in such a way that an envelope made of a gas-tight film is filled with a core material and then sealed in a vacuum-tight manner. In one embodiment, both the filling and the vacuum-tight sealing of the envelope take place at normal or ambient pressure. The evacuation then takes place by connecting a suitable interface incorporated into the envelope, for example an evacuation connection, which can have a valve, to a vacuum pump. During the evacuation there is preferably normal or ambient pressure outside the envelope. In this embodiment, it is preferably not necessary at any point in time during manufacture to introduce the casing into a vacuum chamber. In this respect, in one embodiment, a vacuum chamber can be dispensed with during the production of the vacuum insulation.

A vacuum-tight or diffusion-tight cover or a vacuum-tight or diffusion-tight connection or the term high-barrier film is preferably understood to mean a cover or a connection or a film by means of which the gas entry into the vacuum insulation body is reduced so much that the gas entry caused by gas entry Conditional increase in the thermal conductivity of the vacuum insulation body over its service life is sufficiently low. For example, a period of 15 years, preferably 20 years and particularly preferably 30 years is to be set as the service life. The increase in the thermal conductivity of the vacuum insulation body caused by gas entry over its service life is preferably <100% and particularly preferably <50%.

The area-specific gas transmission rate of the envelope or the connection or the high barrier film is preferably <10-5 mbar * I / s * m ² and particularly preferably <10-6 mbar * I / s * m ² (measured according to ASTM D-3985) . This gas transmission rate applies to nitrogen and oxygen. For other types of gas (especially water vapor) there are also low gas transmission rates, preferably in the range of <10-2 mbar * l / s * m ² and particularly preferably in the range of <10-3 mbar * I / s * m ² (measured according to ASTM F. -1249-90). The aforementioned slight increases in thermal conductivity are preferably achieved through these low gas transmission rates.

An envelope system known from the field of vacuum panels are so-called high-barrier films. In the context of the present invention, these are preferably single or multilayer films (which are preferably sealable) with one or more barrier layers (typically metallic layers or oxide layers, with aluminum or an aluminum oxide preferably being used as the metal or oxide) that have the The above-mentioned requirements (increase in thermal conductivity and / or area-specific gas transmission rate) are sufficient as a barrier against gas entry.

The above-mentioned values or the structure of the high-barrier film are exemplary, preferred details that do not restrict the invention.

The container according to the invention is preferably a refrigerator and / or freezer, the interior of which is cooled by the thermoelectric elements. However, the invention also includes the case that it is a container whose interior is heated by the thermoelectric elements.

The temperature-controlled interior is either cooled or heated depending on the type of device (refrigerator, heating cabinet, etc.).

The refrigerator and / or freezer can be a household appliance or a commercial refrigerator, for example. For example, such devices are included that are designed for a stationary arrangement in the household, in a hotel room, in a commercial kitchen or in a bar. For example, it can also be a wine refrigerator. The invention also includes chest refrigerators and / or freezers. The devices according to the invention can have an interface for connection to a power supply, in particular to a household power supply (e.g. a plug) and / or a standing or installation aid such as adjustable feet or an interface for fixing within a furniture niche. For example, the device can be a built-in device or a floor-standing device.

In one embodiment, the container or the device is designed in such a way that it can be operated with an alternating voltage, for example with a house mains voltage of, for example, 120 V and 60 Hz or 230 V and 50 Hz. In an alternative embodiment, the container or the device is designed in such a way that it can be operated with direct current with a voltage of, for example, 5 V, 12 V or 24 V. In this embodiment it can be provided that a plug-in power supply is provided inside or outside the device, via which the device is operated. One benefit of using Thermoelectric heat pumps in this embodiment is that the entire EMC problem only occurs on the power supply unit.

In particular, it can be provided that the refrigerator and / or freezer has a cabinet-like shape and has a usable space that is accessible to a user on its front side (in the case of a chest, on the top). The usable space can be divided into several compartments, all of which are operated at the same or at different temperatures. Alternatively, only one compartment can be provided. Storage aids such as storage compartments, drawers or bottle holders (also room dividers in the case of a chest) can be provided within the usable space or a compartment in order to ensure optimal storage of refrigerated or frozen goods and optimal use of space.

The usable space can be closed by at least one door that can be pivoted about a vertical axis. In the case of a chest, a flap that can be pivoted about a horizontal axis or a sliding cover is conceivable as a closure element. In the closed state, the door or some other closure element can be connected to the body in an essentially airtight manner by means of a circumferential magnetic seal. The door or some other closure element is preferably also thermally insulated, with the thermal insulation being able to be achieved by means of foaming and, if necessary, by means of vacuum insulation panels, or also preferably by means of a vacuum system and particularly preferably by means of a full vacuum system. Door racks can optionally be provided on the inside of the door in order to be able to store refrigerated goods there as well.

In one embodiment, it can be a small device. In such devices, the usable space, which is defined by the inner wall of the container, for example a volume of less than 0.5 m ³ , less than 0.4 m ³ or less than 0.3 m ³ .

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

However, the invention is not limited to refrigerators and / or freezers, but relates generally to devices with a temperature-controlled interior, for example also warming cabinets or warming chests.

Further details and advantages of the invention are explained in more detail with reference to an embodiment shown in the drawing. The single figure shows a longitudinal sectional view through a refrigerator and / or freezer according to the invention.

In the Figure 1 the body of a cabinet-like refrigerator and / or freezer device is identified by the reference numeral 10.

The body 10 has two side walls 12, a ceiling 14 and a floor 16. Together with the rear wall and a door, these delimit the cooled interior 100.

As can be seen from the figure, a thermoelectric element 20 is provided in each of the two side walls 12, in the top wall 14 and in the bottom 16.

Basically, exactly one such thermoelectric element can be provided per wall. However, the invention also includes the case that in a or more walls two or more than two thermoelectric elements are present.

The arrangement of one or more thermoelectric elements on the rear of the device is also conceivable and encompassed by the invention.

Each of the thermoelectric elements 20 is connected both on the cold side facing the interior space 100 and on the outwardly directed warm side to a respective heat exchanger 30, 40 in a heat-transferring, in particular heat-conducting manner. These primary heat exchangers 30, 40 are metallic bodies, for example made of aluminum.

When the thermoelectric elements 20 are in operation, heat is withdrawn from the cooled interior via their cold side and by means of the heat exchanger 30 and the inner wall I. This heat is dissipated via the warm side of the thermoelectric element 20, the heat exchanger 40 and the outer wall A to the environment.

How this continues from the Figure 1 As can be seen, the cross section of the primary heat exchangers 30, 40 increases starting from the thermoelectric element 20 to the outer wall A and also to the inner wall I, which together with the inside of the door delimits the cooled interior 100. In this way, the waste heat that is drawn off from the interior 100 by means of the thermoelectric elements 20 can be distributed over a larger area without a larger temperature gradient.

The outside of the device is formed by the outer wall A, which consists entirely of a metal sheet, preferably an aluminum sheet.

In the exemplary embodiment shown here, this sheet metal forms the outside A of the side walls 12, the ceiling 14 and also the floor 16. The rear side and / or the door can also be designed accordingly on the outside.

The sheet metal forming the outer wall A forms the secondary heat exchanger, which is connected to the primary heat exchangers 40 in a heat-transferring, in particular heat-conducting manner.

The inner wall I is also formed by a metal sheet, in particular by an aluminum sheet. The inner wall I is in connection with the primary heat exchangers 30 in a heat-transferring, in particular heat-conducting manner.

According to the present invention, the term “heat exchanger” includes any element that is suitable for the transfer of heat. According to the invention, the heat exchangers are formed by metallic bodies.

The reference numeral 50 denotes the thermal insulation which extends between the inner wall I and the outer wall A of the body. This thermal insulation consists of a volume delimited by one or more vacuum-tight foils, in which a core material, in particular perlite, is located. Further insulating materials, such as foaming and / or vacuum insulation panels between the inner wall I and the outer wall A, are preferably not provided.

Corresponding full vacuum thermal insulation can also be provided for the door or some other closure element.

The Peltier elements 20 or the other thermoelectric elements are distributed over the device geometry in such a way that their waste heat is distributed as well as possible over the outer skin A of the device. To distribute the waste heat over the entire outer skin A, it can be constructed from an aluminum sheet with a thickness of 1 to 2 mm.

Since the amount of cold produced is less than the waste heat, there are no such high demands on the heat exchanger inside the device 100. According to the invention, a sheet metal (e.g. an aluminum sheet) that is less thick than the sheet metal forming the outer skin A is also used for the inner wall of the device.

As stated above, a cooling and / or freezing device or a heated container in which different temperature zones prevail can be implemented by separately controlling the thermoelectric elements 20. In principle, however, the invention also includes the case that precisely one temperature prevails in the cooled or heated interior 100.

Depending on the interconnection of the thermoelectric elements, they can heat or cool the interior, so that the container according to the invention can be used for both purposes. The container can thus have a warming function. The exemplary embodiment thus also applies to a heated container with reversely activated thermoelectric elements 20, in which the warm side is on the inside and the cold side is on the outside.

If the container is not required for heating, the same container can be used for cooling by appropriately controlling the thermoelectric elements.

Preferably, only thermoelectric elements are used to control the temperature of the cooled interior.

Claims (10)

1. A temperature-controlled container in cabinet form or chest form having
   a cooled or heated inner space (100); and
   a thermoelectric element (20), in particular having a Peltier element, that is arranged such that the inner space (100) is cooled or heated by means of the thermoelectric element (20), wherein
   a plurality of thermoelectric elements (20) that are arranged at a spatial distance from one another are present for the temperature control of the inner space (100),
   the container has main surfaces that in the case of a container in cabinet form comprise the two side walls, the top wall, the bottom and the rear wall and in the case of a container in chest form comprise the two side walls, the front wall, the rear wall, and the bottom;
   two of the thermoelectric elements (20) are arranged at different main surfaces; and
   the outer skin (A) and the inner wall (I) bounding the inner wall (100) consist completely of sheet metal,
   characterized in that
   the inner wall (I) bounding the inner space (100) has a smaller wall thickness than the outer skin (A) of the container.
2. A container in accordance with claim 1, characterized in that each of the thermoelectric elements (20) are connected in a thermoconductive manner to a respective primary heat exchanger (30, 40) which operates passively both on the cold side and on the hot side.
3. A container in accordance with claim 2, characterized in that each of the two primary heat exchangers (30, 40) consists of a metal body or comprises it, with the metal preferably being aluminum.
4. A container in accordance with claim 2 or claim 3, characterized in that the primary heat exchangers (30, 40) have a cross-sectional area which increases as the spacing from the thermoelectric element increases.
5. A container in accordance with one of the preceding claims, characterized in that the thermoelectric elements (20) are arranged such that they are connected in a heat-transferring manner, in particular in a thermoconductive manner, to the outer skin (A) and to the inner wall (I) of the container bounding the inner space (100) such that the outer skin (A) and the inner wall (I) serve as secondary heat exchangers.
6. A container in accordance with one of the preceding claims, characterized in that the container has a closing element such as a door, a lid or the like; and in that the at least one thermoelectric element (20) is arranged in the closing element.
7. A container in accordance with one of the preceding claims, characterized in that different temperature zones exist in the inner space (100).
8. A container in accordance with one of the preceding claims, characterized in that a control or regulation unit is provided which controls the all of the plurality of thermoelectric elements (20) the same or differently.
9. A container in accordance with one of the preceding claims, characterized in that a thermal insulation is arranged between the inner wall (I) bounding the inner space (100) and the outer wall (A) and comprises a full vacuum system in full or regionally.
10. A container in accordance with one of the preceding claims, characterized in that the container is a refrigerator unit and/or a freezer unit.

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