EP2614324B1 - Refrigeration device with skin condenser - Google Patents

Description

The present invention relates to a refrigerator, in particular a household refrigerator, with a heat-insulating housing surrounding a storage chamber, in which a condenser is integrated into an outer skin of the housing. Such evaporators are also known as skins condenser.

The publication DE 10 2006 061 154 A1 discloses a refrigerator according to the preamble of claim 1.

Conventionally, such a refrigerator comprises an inner container, an outer skin formed at least partly of sheet metal, an insulating material layer enclosed between the inner container and the outer skin, and a refrigerant tube extending on an inner side of the outer skin, between it and the insulating material layer.

Conventionally, refrigerators having such a skin condenser do not have a particularly good efficiency, since the heat released by the condenser in close thermal contact with the insulating material layer is partly not released from the apparatus to the outside, but flows back through the insulating material layer into the storage chamber.

In order to minimize such reflux, the temperature of the condenser must be kept as low as possible. However, in order to achieve a required heat release performance despite low condenser temperature, a large area of the condenser is required. It has therefore already been proposed to arrange a skin condenser distributed over several walls of a refrigerator housing. However, there is the problem that a refrigerant pipe bridging a kink between different outer sides of the refrigerator body parts of the outer skin, as in WO 2008/077699 A1 shown for narrowing tends. While such a constriction at a transition between the condenser and evaporator is quite desirable leads to one or more such constrictions attributable pressure gradient between inlet and outlet of the condenser on the one hand that a high compressor power is required to circulate the refrigerant, on the other causes the adiabatic expansion of the refrigerant at such a bottleneck a cooling that has the consequence that a region of the condenser downstream of such a constriction scarcely contributes to the heat exchange performance.

An alternative is to connect several condenser elements, which are each arranged on an outer side of the refrigerator body, in series with each other. Since these condenser elements must be mounted at substantially the same height to take advantage of the available surface, such a series connection is only practicable if each individual element in the flow direction comprises rising and falling line sections. As a result, liquified refrigerant collects at the lowest local points of the condenser and the still vapor refrigerant has to be pumped through the liquid. Accordingly, at low ambient temperatures, when the proportion of liquid refrigerant in the condenser is relatively high, a large amount of refrigerant is required to force the liquid refrigerant against gravity to the outlet of the condenser. In the liquid ascending bubbles of gaseous refrigerant can lead to disturbing noise. It takes a relatively long time, after the compressor is switched on, that liquid refrigerant is available at the condenser outlet. Energy is lost in each shut-off phase of the compressor, since liquid refrigerant remains in the condenser where it evaporates unused or even displaces liquid refrigerant from the evaporator during evaporation.

Object of the present invention is to provide a refrigeration device with a running on an outer skin of a housing of the device, acting as a condenser refrigerant pipe, which is able to provide liquid refrigerant with little delay and / or to minimize noise during operation.

The object is achieved by providing in a refrigeration appliance, in particular a household refrigeration appliance, with a heat-insulating housing surrounding a storage chamber in which portions of a refrigerant line are arranged in at least two planes on an outer skin of the housing, the sections arranged in the different planes are fluidly connected in parallel , Such a construction allows both unwanted bottlenecks between successive sections the refrigerant line as well as a succession of rising and falling sections to avoid.

Conveniently, the different levels each correspond to different walls of the housing, that is, the arranged in the different levels sections are arranged on different outer surfaces of the housing.

These outer surfaces should comprise at least a rear wall and a side wall of the housing, preferably comprising a rear wall and two side walls.

Each section of the refrigerant line is preferably arranged on a planar board. Two of these boards can be joined together at right angles.

But it can also comprise a single board at least two along a bending line integrally connected parts, on each of which a portion of the refrigerant pipe is arranged.

Each of these portions of the refrigerant piping preferably includes an upstream portion extending from a branch point common to the portions to a vertex extending substantially rectilinearly upward, and a downstream portion extending downwardly in meanders from the vertex.

The sections of the refrigerant line can meet at a dryer or at a throttle.

The parallel arrangement of the sections makes it possible to use for the sections in each case a pipeline with a relatively small cross-section. While in a conventional condenser, a cross section of the pipe of about 10 mm ^{2 is} common, sufficient in the refrigerator according to the invention in each section of the pipe a cross section of less than 5 mm ² .

Fig. 1

eine schematische Darstellung eines Kältemittelkreislaufs eines erfindungsgemäßen Haushaltskältegeräts;

Fig. 2

die räumliche Anordnung der in Fig. 1 gezeigten Komponenten in einem Kältegerät;

Fig. 3

eine Draufsicht auf die Verflüssiger eines Kältegeräts gemäß einer zweiten Ausgestaltung der Erfindung

Fig. 4

einen Schnitt durch die Rückwand eines erfindungsgemäßen Kältegeräts;

Fig. 5

einen zu Fig. 4 analogen Schnitt durch eine Seitenwand des Kältegeräts; und.

Fig. 6

einen zu Fig. 4 analogen Schnitt durch die Rückwand gemäß einer abgewandelten Ausgestaltung.

Further features and advantages of the invention will become apparent from the following description of embodiments with reference to the accompanying figures. Show it:

Fig. 1

a schematic representation of a refrigerant circuit of a household refrigerator according to the invention;

Fig. 2

the spatial arrangement of in Fig. 1 shown components in a refrigerator;

Fig. 3

a plan view of the condenser of a refrigerator according to a second embodiment of the invention

Fig. 4

a section through the rear wall of a refrigerator according to the invention;

Fig. 5

one too Fig. 4 analogous section through a side wall of the refrigerator; and.

Fig. 6

one too Fig. 4 analogous section through the rear wall according to a modified embodiment.

Fig. 1 is a schematic representation of components of the refrigerant circuit of a refrigeration device according to the invention. At a pressure outlet 2 of a compressor 1, a refrigerant pipe 3 connects, which extends over a first branch 4 to a second branch 5. A branch 6 outgoing from the branch 4 runs via a first board 7 to a first confluence 8, a second line 9 extends via a second board 10 from the branch 5 to the confluence 8, and a third line 11 from the branch 5 via a third Board 12 to a second confluence 13. The dimensions of the boards 12 may be different; the lengths of the conduits 6, 9, 11 extending over them are substantially the same, and also their cross-sections are equal and significantly smaller than those of the refrigerant tube 3 or a refrigerant tube 14 extending from the confluence 8 to a drier 15, for a uniform distribution of the refrigerant to the three boards 7, 10, 12 ensure. It is also conceivable to make the line 9 on the smaller board 10 longer than the lines 6, 11 to the larger boards 7, 12 each more than one Supply third of the refrigerant and so make the heat dissipation performance per unit area on all three boards 7, 10, 12 substantially equal.

In the Fig. 1 Separate distributions 4, 5 and confluences 8, 13 can also each lead to a single branch, from which the lines 6, 9, 11 to all three boards 7, 10, 12 emanating, or a single confluence, at which these lines. 6 , 9, 11 merge again, be contracted. Such a branch can be provided directly on the compressor 1, such that each line 6, 9, 11 emanates from its own connection to the housing of the compressor 1. In an analogous manner, the dryer 15 can also act as a confluence by forming separate connections for the lines 6, 9, 11 on its housing.

The lines 6, 9, 11 reach the boards 7, 10, 12 respectively at an inlet port 16 at its lower edge and extend from there on a section 17 substantially vertically up to a peak 18. On the section 17 is found essentially no liquefaction of the refrigerant takes place. This occurs only downstream of the apex 18 on a meandering down section 19, which forms by far the longest part of the lines 6, 9, 11. Refrigerant condensing in this section 19 flows, partly following its own weight, partly flushed with the flow of the not yet liquefied refrigerant, in the direction of an outlet connection 20, likewise at the lower edge of the sinkers 7, 10, 12.

The free diameter of the lines 6, 9, 11 is about 3 mm ^2, only one third of the usual household refrigeration appliances value. Since the refrigerant flow divides substantially uniformly on all three lines 6, 9, 11, the flow rate of the refrigerant in the lines 6, 9, 11 is substantially the same as in a conventional condenser without parallel lines.

The pipes 6, 9, 11 may be soldered to the sinkers 7, 10, 12 or fastened in another manner known per se, so as to form three tube-on-sheet type heat exchanger components 22, 23, 24. In such a heat exchanger, the use of a line with a small cross-section has the advantage that the corresponding tube material is available cheaper than such with a conventional free cross-section of about 10 mm ² . It is also conceivable, however, to realize the heat exchanger components 22, 23, 24 each using Rollbond technology.

The dryer 15 is followed by a capillary 21, which leads to an evaporator 25. Like the heat exchanger components 22-24, this evaporator 25 may be implemented in roll bond or tube on sheet technology. A suction line 26, which leads from the evaporator 25 back to the compressor 1, surrounds the capillary 21 on a part of its length.

Fig. 2 shows in a schematic perspective view of the arrangement of the heat exchanger components 22 - 24 and the evaporator 25 to a housing of a household refrigerator. The housing of the device comprises a body and a door, which, as known per se, are not shown in the figure. The body 1 is assembled in a likewise known manner from a deep-drawn plastic inner container, plate-shaped outer skin elements and insulation material, which fills a gap between the inner container and the outer skin elements. The outer skin elements of side walls of the body may be identical to the boards 7, 12. It is also conceivable to manufacture these outer skin elements in each case from thin sheets, on the inner surfaces of which the blanks 7, 12 are glued or fastened in good heat conduction in other ways which are not recognizable on the outer surfaces of the sheets.

The circuit board 10 of the heat exchanger component 23, which forms an outer skin of the rear wall of the body, and the evaporator 25 bonded to a rear wall of the inner container have a smaller height than the Seitenwandplatinen 7, 12, to make room for a machine room 27 below them, the compressor 1 takes up.

Fig. 3 shows a plan view of three heat exchanger components 22, 23, 24 according to a second embodiment of the invention. The three heat exchanger components 22, 23, 24 are here realized in Rollbond technique on a common planar board 31, on this common board 31 fixed, the lines 6, 9, 11 forming boards 32, 33, 34 are separated from each other by gaps. At bending lines 35 extending through this gap, the blank 31 is bent in order to obtain an arrangement of the heat exchanger components 22, 23, 24 at right angles to one another.

Fig. 4 schematically shows a section through the rear wall of the body, wherein the evaporator 25 carrying the rear wall of the inner container is denoted by 28. Evaporator 25 and component 23 are each of the rollbond type, it being understood that realizations in tube-on-sheet technique are also contemplated for both.

Since, in contrast to the lateral flanks, the rear side of the device housing is generally not visible, the circuit board 10 of the heat exchanger component 23 is exposed at this rear side, in order to allow as unhindered heat emission as possible.

One too Fig. 4 analogous section through a side wall of the body is in Fig. 5 shown. He is different from Fig. 4 on the one hand by the absence of the evaporator between inner container 28 and insulation material 29 and, in the case shown here, an outer skin 30 made of sheet metal, to which the circuit board 7 of the heat exchanger element 22 is adhesively bonded flat.

Unlike the side walls of the body comes on the back wall, an arrangement as in Fig. 6 shown in which the planar board 10 of the heat exchanger component 23 faces the insulating material 29 and the line 9 is exposed at the back of the device. Such an arrangement increases the surface area at which the component 23 can release heat to the environment and reduces the surface area at which it can give off heat to the insulating material 29, thus improving the efficiency of the device.

Claims (10)

1. Refrigeration device, especially household refrigeration device, with a heat-insulating housing (2, 3) surrounding a storage chamber, wherein sections (6, 9, 11) of a coolant line are disposed in at least two planes on an outer skin of the housing, characterised in that the sections (6, 9, 11) disposed in the various planes are connected in parallel in terms of flow technology.
2. Refrigeration device according to claim 1, characterised in that the sections (6, 9, 11) are disposed on different outer surfaces of the housing.
3. Refrigeration device according to claim 2, characterised in that the outer surfaces include at least a rear wall and a side wall of the housing (2, 3).
4. Refrigeration device according to one of the preceding claims, characterised in that the sections (6, 9, 11) are disposed in each case between an external skin (30) and a layer of insulation material (29) of the housing.
5. Refrigeration device according to one of the preceding claims, characterised in that each section (6, 9, 11) is disposed on a flat plate (7, 10, 12).
6. Refrigeration device according to one of claims 1 to 4, characterised in that a plate (31) comprises at least two parts connected as a single part along a bending line (35), and that one section (6, 9, 11) of the coolant line in each case is assigned to each of the parts.
7. Refrigeration device according to one of the preceding claims, characterised in that each section (6, 9, 11) of the coolant line comprises a downstream part (19) running downwards from a crest (18) in serpentine shapes.
8. Refrigeration device according to one of the preceding claims, characterised in that each section (6, 9, 11) of the coolant line comprises an upstream part (17) running continuously upwards from a branching point (4, 5) to a crest (18).
9. Refrigeration device according to one of the preceding claims, characterized in that the sections (6, 9, 11) of the cooling line meet each other at a dryer (15) or a choke point (21).
10. Refrigeration device according to one of the preceding claims, characterized in that the free cross-section of each section (6, 9, 11) of the coolant line amounts to less than 5 mm².

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