EP3155332B1 - Refrigeration and/or freezer device - Google Patents

Description

The present invention relates to a refrigerator and / or freezer with at least one cooled interior and at least one thermoelectric element, in particular with at least one Peltier element, which is arranged such that the interior is cooled by the thermoelectric element.

When opening refrigerators or freezers warm air enters the cooled interior. As the air cools, the saturation vapor pressure decreases, causing moisture to condense from the air to the cold surfaces of the cooled interior.

In known from the prior art refrigerators or freezers, the condensation is collected by the design of the refrigeration system and passed through a gutter or the like to the outside. There it is collected in a thawing tray, which can be located above the compressor. Due to the compressor waste heat evaporates the water in the condensate.

The revelations of US 2009/145138 A1 and the EP 0 368 382 A1 each show a refrigerator or freezer, which has all the features of the preamble of claim 1.

In the case of a thermoelectric refrigerator or freezer, it is expedient for reasons of efficiency to keep the temperature difference at the heat pump markedly smaller than in the case of a compression refrigeration machine. This has the consequence that in the cooled interior no significantly colder area exists, at which the condensation takes place, and that on the outside of the device there is no location with a locally elevated temperature, which could be used to evaporate the condensation water.

The present invention has the object, a cooling and / or freezer of the type mentioned in such a way that a reliable evaporation of the led out of the cooled interior condensation occurs.

The present invention is disclosed in independent claim 1. Further embodiments are disclosed in the dependent claims. In one conceivable case, a device for collecting and discharging condensed water exists on a surface in the cooled interior of the device at which the lowest temperature is present due to the positioning of the thermoelectric cooling. This is led out of the device and enters a collecting tray, which is arranged, for example, around a region of the outer skin at which an elevated temperature is present.

This procedure may be sufficient for moderate climatic conditions. For conditions or regions with a particularly high humidity, the amount of moisture entering may be so great that, on the one hand, due to the low temperature spread, i. H. the low temperature gradient in the interior, the condensation no longer takes place locally at the coldest point. Another problem is that the temperature at the evaporation zone is not high enough to evaporate all condensed water.

To counteract this, it is provided in a further embodiment of the invention that a control or regulation unit is present for carrying out one or more condensation cycles. This unit is designed such that it increases the temperature spread for the purpose of condensation and / or evaporation during a condensation cycle.

This means that during the condensation cycle, the power, for example, of a thermoelectric element is increased such that its temperature in the cooled interior compared to the normal operation in which no Condensation cycle is present, is lowered, and / or that its temperature of the thermoelectric element on the outside of the device over the normal operation in which no condensation cycle is present increases.

The condensation cycle can be carried out at specific intervals, if appropriate at regular intervals, or can depend on one or more parameters. Such a parameter is, for example, the humidity and / or the amount of condensation formed. These parameters may be supplied to the control or regulation unit, which then initiates a condensation cycle in response thereto or continues to operate the device in normal operation. It is conceivable that means may be provided by which it is possible to determine whether condensation water is present and that the control or regulating unit connected to these means may be designed such that the capacity of the means for evaporating condensation water is increased and / or Temperature is lowered at least at one point in the cooled interior, if the presence of condensation is detected.

In order to concentrate the condensate in one place or in several places, it is provided that at least one condensate surface is present in the cooled interior, the temperature of which lies below that of other surfaces in the cooled interior, so that condensate forms on the condensate surface.

The condensate surface is formed by a second thermoelectric element. It may be a thermoelectric element, which is used anyway for cooling the cooled interior or a specially used for the formation of condensate thermoelectric element.

As a result of this additional thermoelectric element, refrigeration and condensate formation are effectively decoupled, so that the boundary conditions of the refrigeration need not be taken into account when designing the condensation geometry.

It is conceivable that a detection means for detecting the opening of the closure element of the device is present and that the control or control unit for cyclical cooling is designed such that it is operated in dependence of the detected opening of the closure element. Thus, one embodiment of the invention may be to initiate the condensation cycle always after a door opening, i. when the door or other closure element is closed again, pass the newly infiltrated warm air over the condensation point.

In order to promote the deposition of moisture on the condensation surface, it may be useful to have a fan arranged to circulate the air in the cooled interior.

Alternatively or additionally, at least one fan may be provided in the evaporation zone to promote the rate of evaporation.

At least one drainage element can be provided, through which condensate water is transported to the means for evaporation.

In the simplest case, the drainage element is arranged so that the condensed water simply flows out of the cooled interior through gravity.

In the refrigerator and / or freezer according to the invention is located between the outer skin, i. the outside of the body and the inner wall defining the cooled interior, and / or between the inside and outside of the door or other closure element preferably a full vacuum insulation. The vacuum insulation body may be located between the outside of the body in the inner container and / or between the outside and the inside of the door or other closure element.

In a preferred embodiment of the refrigerator and / or freezer according to the invention this is thus partially or completely insulated by means of a full vacuum system. This is an arrangement whose thermal insulation between the outside and the interior of the body and / or on the closure element exclusively or predominantly from an evacuated element, in particular in the form of the envelope of vacuum-tight film or high barrier film with a core material. Preferably, the full vacuum insulation is formed by one or more Vakuumdämmkörper, the said film, the region surrounded by the film and the core material located therein. Further thermal insulation by an insulating foam and / or vacuum insulation panel or by another means for thermal insulation between the inside and outside of the device is preferably not provided.

This preferred type of thermal insulation in the form of a full vacuum system may be between the wall bounding the interior space and the outer skin of the body and / or between the inside and outside of the closure element, e.g. a door, flap, cover or the like extend.

The full vacuum system can be obtained by filling a casing of a gas-tight film with a core material and then sealing it in a vacuum-tight manner. In one embodiment, both the filling and the vacuum-tight sealing of the envelope takes place at normal or ambient pressure. The evacuation is then carried out by connecting a suitable incorporated in the envelope interface, such as an evacuation nozzle, which may have a valve to a vacuum pump. Preferably, normal or ambient pressure prevails outside the enclosure during the evacuation. In this embodiment, it is preferably not necessary at any time during manufacture to introduce the envelope into a vacuum chamber. In this respect, it is possible in one embodiment to dispense with a vacuum chamber during the production of the vacuum insulation.

Preferably, the wrapper comprises a high barrier film or is a high barrier film which closes the vacuum region formed by the wrapper in a vacuum tight manner.

Under a vacuum-tight or diffusion-tight envelope or under a vacuum-tight or diffusion-tight connection or the term high barrier film is preferably understood a sheath or a compound or a film, by means of which the gas input is reduced so much in the vacuum insulation that the gas by conditional increase in the thermal conductivity of the vacuum insulation body is sufficiently low over its lifetime. The life span is, for example, a period of 15 years, preferably 20 years and more preferably 30 years. Preferably, the increase in the thermal conductivity of the vacuum insulation body due to the introduction of gas is <100% and particularly preferably <50% over its service life.

Preferably, the area-specific gas transmission rate of the coating or the high barrier film is <10-5 mbar * l / s * m ² and particularly preferably <10-6 mbar * l / s * m ² (measured according to ASTM D-3985 ). This gas passage rate applies to nitrogen and oxygen. For other types of gas (in particular water vapor), low gas flow rates are preferably in the range of <10-2 mbar * l / s * m ² and particularly preferably in the range of <10-3 mbar * l / s * m ² (measured according to ASTM F -1249-90). Preferably, the above-mentioned small increases in the thermal conductivity are achieved by these low gas passage rates.

A known from the field of vacuum panels envelope system are so-called high barrier films. For the purposes of the present invention, preference is given to single-layer or multilayer films (which are preferably sealable) having one or more barrier layers (typically metallic layers or oxide layers, preferably aluminum or an aluminum oxide being used as the metal or oxide), which comprises the mentioned above Requirements (increase in thermal conductivity and / or area-specific gas passage rate) as a barrier against the gas entry suffice.

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

In one embodiment, it is provided that the refrigerator and / or freezer according to the invention is a household appliance or a commercial refrigeration appliance. For example, such devices are included, which are designed for a stationary arrangement in the home, in a hotel room, in a commercial kitchen or in a bar. For example, it may also be a wine refrigerator. Furthermore, refrigerated and / or freezers are also included in the invention. The devices according to the invention may have an interface for connection to a power supply, in particular to a household power grid (eg a plug) and / or a standing or installation aid such as feet or interface for fixing within a furniture niche. For example, the device may be a built-in device or a stand-alone device.

In one embodiment, the container or device is designed to be connected to an AC voltage, such as a home voltage of e.g. 120 V and 60 Hz or 230 V and 50 Hz can be operated. In an alternative embodiment, the container or the device is designed such that it can be operated with direct current of 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. An advantage of the use of thermoelectric heat pumps in this embodiment is that the complete EMC problem only occurs on the power supply.

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

The useful space can be closed by at least one door pivotable about a vertical axis. In the case of a chest, a flap pivotable about a horizontal axis or a sliding lid is conceivable as a closure element. The door or other closure element can be in the closed state by means of a peripheral magnetic seal with the body substantially airtight in combination. Preferably, the door or another Heat-insulated closure element, wherein the heat insulation can be achieved by means of a foaming and optionally by means of vacuum insulation panels, or preferably by means of a vacuum system and particularly preferably by means of a full vacuum system. If necessary, door racks can be provided on the inside of the door in order to be able to store refrigerated goods there as well.

In one embodiment, it may be a small appliance. In such devices, the work space defined by the inner wall of the container has, 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 outer dimensions of the container or device are preferably in the range up to 1 m in terms of height, width and depth.

Figur 1:

eine Längsschnittansicht durch ein Kühl- und/oder Gefriergerät gemäß der Erfindung; und

Figur 2:

eine Detailansicht des Bereichs eines thermoelektrischen Elements, dessen warme Seite die Verdunstung von Kondenswasser begünstigt.

Further details and advantages of the invention will be explained in more detail with reference to the embodiment shown in the figures and described below. In the figures show:

FIG. 1:

a longitudinal sectional view through a refrigerator and / or freezer according to the invention; and

FIG. 2:

a detailed view of the area of a thermoelectric element whose warm side favors the evaporation of condensed water.

In FIG. 1 is denoted by the reference numeral 10, the body of a cabinet-like refrigerator and / or freezer.

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

Like this FIG. 1 shows, in the two side walls 12, in the top wall 14 and in the bottom 16 each have a thermoelectric element 20, 20 'is provided.

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

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

Each of the thermoelectric elements 20 is both on the facing to the interior 100 cold side and on the outward warm side, each with a heat exchanger 30, 40 heat-transmitting, in particular thermally conductive in connection. These primary heat exchangers 30, 40 are metallic bodies, e.g. made of aluminium.

During operation of the thermoelectric elements 20, heat is removed from the cooled interior via its 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.

Like this further FIG. 1 As can be seen, the cross-section of the primary heat exchanger 30, 40 increases from the thermoelectric element 20 to the outer wall A and also to the inner wall I, which limits the cooled interior 100 together with the inside of the door. In this way, the waste heat by means of the thermoelectric elements 20 from the Interior 100 is withdrawn without distributing a larger temperature gradient over a larger area.

The outside of the device is formed by the outer wall A, which consists of a metal sheet, preferably aluminum sheet, in whole or in part.

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

The sheet forming the outer wall A forms the secondary heat exchanger, which communicates with the primary heat exchangers 40 in a heat-transmitting, in particular heat-conducting, connection.

The inner wall I is likewise formed by a metal sheet, in particular by an aluminum sheet. The inner wall I is heat-transmitting, in particular thermally conductive with the primary heat exchangers 30 in connection.

The term "heat exchanger" according to the present invention includes any element suitable for transferring heat. In the preferred embodiment, 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 limited by one or more vacuum-tight films volume in which a core material, in particular perlite is located. Preferably, further insulating materials, such as a foaming and / or Vacuum insulation panels between the inner wall I and the outer wall A is not provided.

A corresponding full vacuum thermal insulation can also be provided for the door or another closure element.

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

Since the resulting amount of cold is less than the waste heat, there are no such high demands on the heat exchanger inside the device 100. Preferably, however, a sheet (e.g., an aluminum sheet) which may have a lower thickness than the sheet forming the outer skin A or may be identically formed is also used for the inner wall of the apparatus.

The thermoelectric element 20 'arranged at the bottom communicates with its cold side with the heat exchanger 30, which forms a condensation surface on its upper side O, i. an area which is lower in temperature than adjacent areas or which is the lowest temperature in the cooled interior.

A detailed view of the region of the thermoelectric element 20 'arranged below is shown in FIG FIG. 2 shown. Around and at the condensation surface of the heat exchanger 30, a condensation region 1 is formed. Starting from this condensation region 1 on the inside of the heat-insulating Device wall leads a drain 2 for the condensate to the evaporation area 200.

The evaporation zone 200 is formed by an evaporation tray 4, which collects the condensation and which is in good thermal coupling to the Peltier element 20 '. In particular, the evaporation tray 4 is in direct or at least heat-conducting contact with the heat exchanger 40.

Like this further out FIG. 2 can be seen, the Peltier element 20 'as well as the other Peltier elements of the device according to the invention comprise connecting elements 33 which mechanically clamp the Peltier element 20' with the heat exchangers 30 and 40.

The thermoelectric element or Peltier element 20 'arranged in the bottom surface can be controlled separately by a control or regulating unit, not shown, in such a way that its power is increased within the scope of a condensation cycle or as required. This has the consequence that the upper cold side O assumes an even lower temperature and the lower warm side W assumes an even higher temperature. In this way, the condensation and evaporation is improved.

In normal operation, the thermoelectric element 20 'as well as the other thermoelectric elements depending on the measured indoor temperature, i. used for temperature control.

It is also conceivable to use an additional thermoelectric element, which rests, for example, on the bottom surface of the device and there forms the coldest Stellte. This thermoelectric element thus does not extend between Outside and inside of the device, but is located entirely in the cooled interior and emits in this his waste heat, which is not part of the present invention.

Claims (8)

1. A refrigerator unit and/or a freezer unit (10) having a refrigerated inner space (100), having a first thermoelectric element (20), in particular having a Peltier element, that is arranged such that the inner space (100) is refrigerated by means of the thermoelectric element (20), and having means (4, 40) for evaporating condensed water that have a heat exchanger (40) located outside the refrigerated inner space (100) and an evaporation tray (4), wherein a condensate surface (1) is present in the refrigerated inner space (100) whose temperature is below the temperature of other surfaces in the refrigerated inner space (100) so that condensate is formed at the condensate surface (1), characterized in that the condensate surface (1) is formed by a second thermoelectric element (20') that is arranged such that it emits its waste heat to the heat exchanger (40) outside the refrigerated inner space (100).
2. A refrigerator unit and/or a freezer unit (10) in accordance with claim 1, characterized in that the heat exchanger (40) is formed by the hot side of the second thermoelectric element (20') or is connected to the hot side of the second thermoelectric element (20').
3. A refrigerator unit and/or a freezer unit (10) in accordance with claim 2, characterized in that the first thermoelectric element (20) is arranged such that it cools the inner space (100) of the unit by its cold side or by a heat exchanger (30) connected to the cold side.
4. A refrigerator unit and/or a freezer unit (10) in accordance with one of the preceding claims, characterized in that means are provided by which it can be determined whether condensed water is present; and in that a control or regulation unit connected to these means is provided that increases the performance of the means (4, 40) for evaporating condensed water when the presence of condensed water is determined.
5. A refrigerator unit and/or a freezer unit (10) in accordance with one of the preceding claims, characterized in that a control or regulation unit is provided by which the condensate surface (1) is cyclically cooled.
6. A refrigerator unit and/or a freezer unit (10) in accordance with claim 5, characterized in that a detection means for detecting the opening of the closing element of the unit (10) is present; and in that the control or regulation unit is configured such that it carries out the cyclic cooling in dependence on the detected opening.
7. A refrigerator unit and/or a freezer unit (10) in accordance with one of the preceding claims, characterized in that a fan is present that is arranged such that it circulates the air located in the refrigerated inner space (100).
8. A refrigerator unit and/or a freezer unit (10) in accordance with one of the preceding claims, characterized in that an outflow element (2) is provided through which the condensed water is transported to the means (4, 40) for evaporation.

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