DE102015216078A1 - Domestic refrigerating appliance with a pressure compensation element of a secondary refrigeration circuit, which is not surrounded by insulation foam - Google Patents

Abstract

The invention relates to a domestic refrigeration appliance (1), with a housing (7) in which an interior (3, 4) is designed for receiving food, with a primary refrigeration circuit (8) thermally coupled to a cold storage (11) is, and with a first heat exchanger (13) having secondary refrigeration circuit (10) which is thermally coupled to the cold storage (11) and for cooling the interior (3, 4) formed and to the interior (3, 4) thermally coupled, and the secondary refrigeration cycle (10) undeformable and by a thermal insulation foam (21) surrounded lines (18, 19) of the secondary refrigeration cycle (10), wherein the secondary refrigeration cycle (10) one of the thermally insulating Insulation foam (21) not surrounded and deformable and by the refrigerant in the secondary refrigeration cycle (10) through-flow pressure compensation element (20), which is dependent on a in the operation of the secondary Kältkreislau fs (10) occurring negative pressure in the lines (18, 19) deformed.

Description

The invention relates to a household refrigerator, which has a housing in which an interior is designed for receiving food. The domestic refrigerator comprises a primary refrigeration cycle which is thermally coupled to a cold storage of the household refrigerator. In addition, the household refrigerator comprises a secondary refrigeration circuit which is separate from the primary refrigeration cycle and has a first heat exchanger. The secondary refrigeration cycle is thermally coupled to the cold storage and is designed to cool the interior and to thermally coupled to the interior. The secondary refrigeration cycle has undeformable and surrounded by a thermal insulation foam lines.

Such a configuration is known in household refrigerators.

Also, so-called no-frost household refrigerators are known, for example from the DE 10 2010 041 952 A1 ,

In a no-frost domestic refrigeration appliance, in which an objective cold storage is present in particular as a separate container in which a storage medium is contained, this cold storage is cooled by means of the primary refrigeration cycle. The already mentioned secondary refrigeration cycle, which is a brine circuit (refrigeration oil circuit), usually has a pump, through which the "cold" is conveyed to the no-frost unit and thus in particular in the first heat exchanger.

From the GB 2 057 109 A is a refrigerator with a primary refrigeration cycle, a secondary refrigeration cycle and a cold storage, with which the two refrigeration circuits are thermally coupled, shown.

Furthermore, from the DE 10 2011 079 208 A1 a no-frost household refrigeration appliance is known. From this document, a method for defrosting an evaporator and thus also a heat exchanger is known.

In a domestic refrigerator with such a cold storage thus the cooling compartments or the interiors in which food can be introduced, cooled. The refrigerant or coolant present in this refrigerant circuit or secondary refrigeration cycle is pumped by the heat exchanger in the cold storage tank by means of a feed pump of the secondary refrigeration cycle. There, the refrigerant is cooled and then passed through another heat exchanger, namely the first heat exchanger, which cools the cold rooms of the household refrigerator or the no-frost unit.

It is common for the secondary refrigeration cycle to be filled with the refrigerant at room temperature during production and thus production of the household refrigerating appliance and then closed. If the household refrigerator is then put into operation, the secondary refrigeration cycle cools down and there is a negative pressure due to the volume contraction of the fluid or the refrigerant. Since the secondary refrigeration cycle is largely installed in a thermally insulating foam of the household refrigerator, the lines of the secondary refrigeration cycle must be made of a mechanically resistant material, which withstands the mechanical pressure of the insulating foam during production and thus during foaming. Due to this rigid design of the pipes or lines of the secondary refrigeration cycle, this secondary refrigeration circuit can not compensate for the negative pressure by deformation and it can lead to the intake of false air or cavitation effects in the feed pump. This can result in a reduced service life of the feed pump. Even stalls of the refrigerant in the secondary refrigeration cycle can occur. In addition, an additional noise during operation of the household refrigerator may occur.

It is an object of the present invention to provide a household refrigerator, in which a due to the above conditions associated negative pressure in the secondary refrigeration cycle can be compensated.

This object is achieved by a household refrigerator according to claim 1.

An inventive household refrigerator comprises a housing in which an interior space for storing food is formed. The domestic refrigerator comprises a primary refrigeration cycle which is thermally coupled to a cold storage of the household refrigerator. The primary refrigeration cycle is a self-contained circuit in which refrigerant circulates. The domestic refrigerator also includes a secondary refrigeration cycle separate from the primary refrigeration cycle. The secondary refrigeration cycle has a first heat exchanger. The secondary refrigeration cycle is also thermally coupled to the cold storage. The secondary refrigeration cycle is designed to cool the interior and to thermally coupled to the interior. The secondary refrigeration cycle has undeformable and surrounded by a thermal insulation foam lines connecting components of the secondary refrigeration cycle, on. With the thermal insulation foam is the Interior thermally insulated to the outside. In particular, the thermal insulation foam between an inner container, which limits the interior with its walls, and a housing which accommodates the inner container, is arranged. These non-deformable lines are thus laid in the thermal insulation foam.

The thermal insulation foam is introduced in the production of household refrigeration appliance after these lines of the secondary refrigeration cycle are already laid. The secondary refrigeration cycle can already be filled and closed with the refrigerant at this time of production. In particular, the filling is made only when the insulation foam is introduced.

An essential idea of the invention is to be seen in that the secondary refrigeration cycle has a pressure compensation element which is not surrounded and deformable by the thermally insulating insulation foam and also flows through the refrigerant or refrigerant in the secondary refrigeration cycle. The pressure compensation element deforms depending on a negative pressure occurring in the lines during operation of the secondary refrigeration cycle. It is thus formed in accordance with the invention, the secondary refrigeration cycle with respect to its local arrangement and physical design in its lines so that a portion or a portion outside the thermally insulating insulation foam is laid and then this section is also elastically deformable and forms a pressure compensation element.

By such a configuration, the negative pressure which is generated in normal operation by cooling the secondary refrigeration cycle can be compensated. This can also be avoided in a simple manner, the intake of false air or the occurrence of cavitation effects in a feed pump of the secondary refrigeration cycle. As a result, the premature wear of the pump is avoided. In addition, stalls of the refrigerant can be avoided in the secondary refrigeration cycle and an undesirable noise, as is the case in the prior art, can be prevented.

In particular, the household refrigerator is a no-frost domestic refrigeration appliance. A no-frost household refrigerator is equipped with a no-frost technology. As a no-frost technique, a technical process is referred to, in which the humidity is reduced in a designed as a freezer compartment interior. As a result, the food does not frost or significantly reduced and a defrosting of the freezer compartment can be omitted or only needs to be carried out in significantly reduced time cycles. In such a no-frost technique, for example, cooling elements designed as cooling fins and thus a heat exchanger of the secondary circuit lie in a separate area in the interior space. During the cooling phase, the cold air is then introduced from this separated area in the interior and thus the freezer compartment by a fan. These devices are designed so that air circulates through all compartments of the interior and enters the cycle again in the separated area. Since cold air holds less moisture, it precipitates as frost primarily only at the heat exchanger of the secondary refrigeration cycle which is in the separated area and is the coldest point in the no-frost home appliance having contact with air. It may then be provided that a defrost mode is performed at specific time intervals, in which this first heat exchanger is defrosted in the separated area. For this purpose, in particular a heating device is provided in the no-frost domestic refrigeration appliance, by which a heating of this heat exchanger is performed. The resulting then from the thawing ice layer water can run out of the interior and thus also from the device via a gutter and can be collected in a collecting bowl, which can also serve as an evaporation tank. In particular, the fan is deactivated in the defrost mode, so that the freezer compartment remains cooled. Thanks to the no-frost technology, the freezing of cooling fins is significantly reduced and the humidity in the entire domestic refrigeration unit drops, which also significantly reduces the formation of ice layers.

It is preferably provided that the pressure compensation element is a hose. This is a very simple and cost-effective component, which allows the above-mentioned functionality to a particular extent and permanently provides without restrictions. In addition, it is insensitive to different environmental influences, as may be the case on the one hand by the refrigerant, on the other hand by the ambient temperatures.

It is preferably provided that the pressure compensation element is a hollow body which is radially deformable. The compensation of occurring negative pressure can be done particularly advantageous. A very rapid reaction of the required deformation of the pressure compensation element is thereby given, so that it is also reacted immediately to the occurrence of a negative pressure in the secondary refrigeration cycle.

It can be provided that the pressure compensation element is made of elastomer. This material specification allows a special longevity of the pressure compensation element and a special robust design against different environmental influences. A special In addition, quick ductility is given. It can be provided that an embodiment of an elastomer is, for example, silicone or a thermoplastic elastomer or rubber.

It can be provided that the pressure compensation element has a length between 30 mm and 40 mm, in particular between 34 mm and 36 mm. As a result, a relatively small pressure compensation element is provided which thus requires little space outside of the thermal insulation foam. In addition, therefore, only a very small piece of the secondary refrigeration cycle with respect to the wiring is not surrounded by a thermally insulating material, so that only extremely low thermal losses occur. In addition, this design of the pressure compensation element also allows a simple shoring and, with respect to this relatively short and small dimensioning of the pressure compensation element, nevertheless permits a sufficient vacuum equalization.

It is provided in particular that the pressure compensation element has an inner diameter between 25 mm and 35 mm, in particular between 28 mm and 30 mm. As a result, it is advantageously adapted to dimensions of the laid in the thermal insulation foam and surrounded by the thermal insulation foam lines of the secondary refrigeration circuit, so that no undesirable flow disadvantages occur at the transition between the insulating foam embedded lines and the pressure compensation element. Preferably, in the deformed state of the pressure compensation element, the inner diameter is still at least as large as the inner diameter of the line connected to the pressure compensation element.

It is preferably provided that the secondary refrigeration cycle has a pump, not surrounded by the insulating foam, with which the refrigerant is circulated. It may be provided in an advantageous embodiment, that the pressure compensation element is then installed directly to the pump. For a simple connection is possible and on the other hand, those components that should be located outside the thermally insulating insulation foam from a technical point of view, directly next to each other, so that even here no complex attachment of the insulating thermal insulation foam is required. The production is simplified.

It can also be provided that the secondary refrigeration cycle has a pump, not surrounded by the insulating foam, with which the refrigerant is circulated, and the first heat exchanger is arranged between the pressure compensation element and the pump in the secondary refrigeration cycle. In the flow direction of the refrigerant in the secondary refrigeration cycle, the pressure compensation element and the pump is then arranged on opposite delivery sides of the first heat exchanger and connected in a secondary refrigeration cycle.

It can be provided that the secondary refrigeration cycle has a second heat exchanger, which is thermally coupled to the cold storage. In particular, the second heat exchanger is arranged in the cold storage. The pump is then viewed in particular in a conduction path in the flow direction of the refrigerant therein, disposed between the first heat exchanger and the second heat exchanger. The pressure compensation element and the pump are thus not connected to each other in such a configuration directly via a line, but both downstream and upstream, a heat exchanger is connected in between.

It may be provided that the secondary refrigeration cycle has a second heat exchanger, which is thermally coupled to the cold storage, in particular arranged therein, and the pressure compensation element is arranged in a conduction path in the flow direction of the refrigerant therein between the second heat exchanger and the first heat exchanger ,

The terms "top", "bottom", "front", "rear", "horizontal", "vertical", "depth direction", "width direction", "height direction" are the intended use and intended arrangement of the device and a then given in front of the device and given in the direction of the device observer given positions and orientations.

Further features of the invention will become apparent from the claims, the figures and the description of the figures. The features and feature combinations mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respectively specified combination but also in other combinations or in isolation, without the frame to leave the invention. Thus, embodiments of the invention are to be regarded as encompassed and disclosed, which are not explicitly shown and explained in the figures, however, emerge and can be produced by separated combinations of features from the embodiments explained. There are also versions and feature combinations to be regarded as disclosed, which thus does not have all the features of originally formulated independent claim.

Embodiments of the invention are explained in more detail below with reference to schematic drawings. Show it:

1 a schematic perspective view of an embodiment of a household refrigerator according to the invention;

2 a simplified representation of a secondary refrigeration cycle of the no-frost household refrigeration appliance according to 1 ; and

3 a schematic sectional view in the upper picture by an embodiment of a pressure compensation element in the normal state and in the lower image in 3 a schematic sectional view of the pressure compensation element in a deformed state generated due to a negative pressure in the secondary refrigeration cycle.

In the figures, identical or functionally identical elements are provided with the same reference numerals.

In 1 is a schematic representation of a household refrigerator 1 shown which is a no-frost household refrigerator. The household refrigerator 1 includes an inner container 2 passing through walls a first interior 3 which is a freezer compartment and a second interior 4 which is a refrigerator, limited. The interior 3 is from the interior 4 separated. The interior 3 is through a door 5 can be closed at the front. Independent of this is a door 6 designed to close the interior 4 is trained.

The interior 3 For example, it is used for freezing foods. Also in the interior 4 Food can be introduced, however, compared to the interior 3 at higher temperatures, especially at temperatures greater than 0 ° C.

The inner container 2 is in a housing 7 of the household refrigerator 1 arranged.

The household refrigerator 1 has a refrigeration cycle. This includes in the exemplary embodiment a primary refrigeration cycle 8th ( 2 ), which is a self-contained refrigeration cycle and in 2 only partially shown. The primary refrigeration cycle 8th is a compressor refrigeration cycle.

The primary refrigeration cycle 8th includes, as in 2 is shown, a first heat exchanger 9 , which is designed as an evaporator. The primary refrigeration cycle 8th moreover comprises a compressor, not shown, and a condenser, not shown. The primary refrigeration cycle 8th is not directly with the interior 3 and not directly with the interior 4 thermally coupled. This includes the household refrigerator 1 a self-contained secondary refrigeration cycle 10 that is to the primary refrigeration cycle 8th is separate circuit and with the primary refrigeration cycle 8th thermally coupled. This is a cold storage 11 provided in which a storage medium 12 , For example, a salt solution or a phase change material are included. The primary cycle 8th is with the cold storage 11 thermally coupled. Also the secondary refrigeration cycle 10 is with this cold storage 11 thermally coupled. In the exemplary embodiment, it is provided that the first heat exchanger 9 of the primary refrigeration cycle 8th in the cold storage 11 is arranged and from the storage medium 12 is surrounded. The secondary refrigeration cycle 10 includes a first heat exchanger 13 that with the interior 3 and in the embodiment also with the interior 4 thermally coupled. This is an area 14 formed by a partition 15 from the rest of the interior 3 and in the embodiment of the interior 4 is separated. The first heat exchanger 13 is in the area 14 arranged. The partition 15 has openings, so that of the first heat exchanger 13 cooled air in the area 14 , in particular by a fan, not shown, circulating from the area 14 over the opening of the partition 15 in the remaining interior 3 and in the embodiment also in the interior 4 can get over and then more openings from the interior 3 and in the embodiment also of the interior 4 back to the area 14 flows.

The secondary refrigeration cycle 10 also includes a second heat exchanger 16 , which in the cold storage 11 is arranged and from the storage medium 12 is surrounded.

The secondary refrigeration cycle 10 also includes a feed pump 17 that in a line 18 is switched, and in by the predetermined in the embodiment of the conveying direction of the refrigerant downstream of the second heat exchanger 16 and upstream of the first heat exchanger 13 is arranged.

In addition, in another line 19 , which, in view of the flow direction of the refrigerant between the first heat exchanger shown in the embodiment 13 and the second heat exchanger 16 extends, a pressure compensation element 20 arranged. The pressure compensation element 20 is in the embodiment preferably a hose and thus a radially deformable hollow body. This pressure compensation element 20 has a length between preferably 30 mm and 40 mm, in particular between 34 mm and 36 mm. In addition, it has in particular an inner diameter between 25 mm and 35 mm, in particular between 28 mm and 30 mm.

The wires 18 and 19 are of a thermally insulating insulating foam 21 surround. The pump 17 and the pressure compensation element 20 are of this thermally insulating insulating foam 21 not surrounded. The wires 18 and 19 are formed of a rigid, non-deformable material.

In 3 is in a simplified sectional view in the upper picture, the pressure compensation element 20 shown in the undeformed state. It has two connections 22 and 23 on, with which the pressure compensation element 20 into the pipe 19 is installed. As can be seen, this inner diameter d is significantly larger than the inner diameter at the connecting piece 22 and 23 ,

Due to the above, occurs in the operation of the no-frost household refrigeration appliance 1 in this secondary refrigeration cycle 10 a negative pressure, which is compensated by the fact that the pressure compensation element 20 , which of the thermally insulating insulating foam 21 is not specifically surrounded, deformed, in particular radially deformed and contracts. This is in the picture below 3 shown. The pressure compensation element 20 is then shown compressed, but only in such a way that the refrigerant can still flow through. At the in 2 embodiment shown is the pressure compensation element 20 thus spaced and far from the feed pump 17 in the conduction path of the secondary refrigeration cycle 10 arranged. Viewed in the conveying direction of the refrigerant is upstream of the feed pump 17 considered between the feed pump 17 and the pressure compensation element 20 the second heat exchanger 16 switched or arranged, and downstream of the feed pump 17 considers the first heat exchanger 13 between the feed pump 17 and the pressure compensation element 20 arranged.

In a further embodiment it can be provided that the pressure compensation element 20 directly to the feed pump 17 connected. Also by these embodiments, the volume contraction of the refrigerant is easily and extensively balanced.

The volume of the pressure compensation element 20 is generally chosen so that the volume contraction of the whole in the secondary refrigeration cycle 10 located refrigerant can be compensated.

In particular, it is provided that the connecting pieces 22 and 23 are made of a rigid material, in particular plastic, and are preferably produced as injection-molded parts. This allows a mechanically stable connection with the line 19 or the line 18 respectively. Due to the specific design and geometry of the pressure compensation element 20 even small and negligible pressure losses are given. Depending on the inner diameter d and the geometric design of the connecting piece 22 and 23 can be done an individual fluidic adaptation, so that there are also further benefits then. Especially in the case of the abovementioned specific geometries and values of the length and / or the inner diameter, the pressure compensation element becomes 20 only contracted so far that almost no influence on the flow of the refrigerant occurs.

In particular, it is possible that at least temporarily simultaneously the heat exchanger 13 can be defrosted, for example by a heater, and the cold storage 11 , in particular the storage medium 12 , can be cooled and thus can be charged.

LIST OF REFERENCE NUMBERS

1

 Household refrigerator

2

 inner container

3

 inner space

4

 inner space

5

 door

6

 door

7

 casing

8th

 Primary refrigerant circuit

9

 first heat exchanger

10

 Secondary refrigerant circuit

11

 cold storage

12

 storage medium

13

 first heat exchanger

14

 Area

15

 partition wall

16

 second heat exchanger

17

 feed pump

18

 management

19

 management

20

 Pressure compensation element

21

 thermally insulating insulating foam

22

 spigot

23

 spigot

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102010041952 A1 [0003]
• GB 2057109 A [0005]
• DE 102011079208 A1 [0006]

Claims (11)

Household refrigeration appliance ( 1 ) with a housing ( 7 ), in which an interior ( 3 . 4 ) is designed to receive food, with a primary refrigeration cycle ( 8th ), which with a cold storage ( 11 ) is thermally coupled, and with a first heat exchanger ( 13 ) having secondary refrigeration circuit ( 10 ), which with the cold storage ( 11 ) is thermally coupled and for cooling the interior ( 3 . 4 ) and with the interior ( 3 . 4 ) is thermally coupled, and the secondary refrigeration cycle ( 10 ) undeformable and by a thermal insulation foam ( 21 ) surrounded lines ( 18 . 19 ) of the secondary refrigeration cycle ( 10 ), Characterized in that the secondary refrigerant circuit ( 10 ) one of the thermally insulating insulating foam ( 21 ) not surrounded and deformable and of refrigerant in the secondary refrigeration cycle ( 10 ) through-flow pressure compensation element ( 20 ), which depends on a during operation of the secondary refrigeration cycle ( 10 ) occurring negative pressure in the lines ( 18 . 19 ) is deformable. Household refrigeration appliance ( 1 ) according to claim 1, characterized in that the pressure compensation element ( 20 ) is a hose. Household refrigeration appliance ( 1 ) according to claim 1 or 2, characterized in that the pressure compensation element ( 20 ) is a hollow body which is radially deformable. Household refrigeration appliance ( 1 ) according to one of the preceding claims, characterized in that the pressure compensation element ( 20 ) is made of elastomer. Household refrigeration appliance ( 1 ) according to one of the preceding claims, characterized in that the pressure compensation element ( 20 ) has a length between 30 mm and 40 mm, in particular between 34 mm and 36 mm. Household refrigeration appliance ( 1 ) according to one of the preceding claims, characterized in that the pressure compensation element ( 20 ) has an inner diameter (d) between 25 mm and 35 mm, in particular between 28 mm and 30 mm. Household refrigeration appliance ( 1 ) according to one of the preceding claims, characterized in that the secondary refrigeration cycle ( 10 ) one of the insulation foam ( 21 ) not surrounded pump ( 17 ), with which the refrigerant is circulated, and the pressure compensation element ( 20 ) directly to the pump ( 17 ) is then installed. Household refrigeration appliance ( 1 ) according to one of the preceding claims, characterized in that the secondary refrigeration cycle ( 10 ) one of the insulation foam ( 21 ) not surrounded pump ( 17 ), with which the refrigerant is circulated, and the first heat exchanger ( 13 ) between the pressure compensation element ( 20 ) and the pump ( 17 ) in the secondary refrigeration cycle ( 10 ) is arranged. Household refrigeration appliance ( 1 ) according to claim 8, characterized in that the secondary refrigeration cycle ( 10 ) a second heat exchanger ( 16 ), which with the cold storage ( 11 ) is thermally coupled, in particular arranged therein, and the pump ( 17 ) in a line ( 18 ) between the first heat exchanger ( 13 ) and the second heat exchanger ( 16 ) is arranged. Household refrigeration appliance ( 1 ) according to one of the preceding claims, characterized in that the secondary refrigeration cycle ( 10 ) a second heat exchanger ( 16 ), which with the cold storage ( 11 ) is thermally coupled, in particular arranged therein, and the pressure compensation element ( 20 ) in a line ( 19 ) between the second heat exchanger ( 16 ) and the first heat exchanger ( 13 ) is arranged. Household refrigeration appliance ( 1 ) according to one of the preceding claims, characterized in that it is a no-frost domestic refrigeration appliance ( 1 ).

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