EP3869130A1 - Refrigeration device with finned evaporator - Google Patents

Abstract

A refrigeration device has at least one, preferably several temperature zones, each with a storage chamber (26b, c) and an evaporator chamber (18a, b, c) assigned to the storage chamber (26b, c). The evaporator chamber (18a, b, c) extends in a first spatial direction along the storage chamber (26b, c) and communicates via inlet and outlet openings (23a, b, c; 22a, b, c) spaced apart in the first spatial direction with the Storage chamber (26b, c). A fan (25) is arranged at an outlet opening (22a, b, c) in order to suck air out of the evaporator chamber (18a, b, c) and to expel it into the storage chamber (26b, c). The fan (25) is at least one radial fan, the axis of rotation (34) of which is oriented in the first spatial direction.

Description

The present invention relates to a refrigeration device, in particular a household refrigeration device, with an evaporator chamber and a first evaporator module arranged in the evaporator chamber. In such a refrigeration device, also referred to as a no-frost device, a storage chamber is cooled in that air is exchanged between the evaporator chamber and the storage chamber.

The evaporator chamber generally extends either between a rear wall of a body of the refrigeration device and a vertical partition wall to the storage chamber, and the lamellar evaporator therein is oriented on edge, or it extends between a ceiling of the body and a partition sloping in the depth direction of the body, and the lamellar evaporator is inclined parallel to the partition wall.

In recent years, many refrigeration device models have come onto the market which, in addition to the usual storage chambers, normal refrigeration compartment and freezer compartment, also have storage chambers for other temperature ranges or for storage under high or low humidity. Some devices even allow a storage chamber to be operated at a temperature higher than the ambient temperature by condensing refrigerant in the evaporator of the storage chamber in question instead of evaporating it. In order to be able to control the temperature of these chambers in an energy-efficient way and to prevent the spread of odors from one chamber to the other, each chamber should have its own evaporator, if possible. Most of these chambers are arranged one above the other, ie the more storage chambers have to be accommodated in a body of given external dimensions, the lower the storage chambers have to be. If the height is low, however, the conventional designs of the evaporator chamber become uneconomical; if a fan for circulating the air has to be accommodated above the evaporator with an evaporator chamber arranged on the rear wall, there is not enough installation height left for the evaporator itself; In the case of an evaporator chamber on the ceiling, too much overall height is lost if a separate evaporator is to be accommodated for each storage chamber.

For the cooling of a storage chamber with a low overall height, novel concepts for air routing are therefore required.

the end KR 19980018857 U a refrigeration device with two storage chambers arranged one above the other is known, each of which is assigned its own evaporator. While the upper evaporator chamber extends vertically along a rear wall of the storage chamber as described above and communicates with the storage chamber via vertically spaced inlet and outlet openings, and an axial fan at the outlet opening drives the exchange of air, the lower, much higher storage chamber is a vertically elongated, horizontal one assigned through flow evaporator. In order to flow through this over its entire height, a likewise vertically elongated fan rotating about a vertical axis is proposed. Since this fan must suck in from the radial direction as well as discharge in the radial direction, and no precautions can be seen that could prevent air from being conveyed back from the outlet to the inlet inside the fan, the efficiency of the fan is low.

There is therefore a need for a refrigeration device that enables efficient cooling and air guidance even with a low overall height of a storage chamber.

According to the invention, this need is satisfied in that, in a refrigeration device with at least one temperature zone comprising a storage chamber and an evaporator chamber assigned to the storage chamber, the evaporator chamber extending in a first spatial direction along the storage chamber and via inlet and outlet openings spaced in the first spatial direction with the storage chamber communicates and a fan is arranged at an outlet opening to suck air out of the evaporator chamber and expel it into the storage chamber, the fan is at least one radial fan whose axis of rotation is oriented in the first spatial direction. As a result, the space requirement of the fan in the first spatial direction can be reduced considerably, and the dimensions of the evaporator in the first spatial direction can be selected to be correspondingly larger.

In terms of the utilization of space, it is particularly advantageous if a partition between the storage compartment and the evaporator chamber is in the first spatial direction and one in addition extends orthogonal second spatial direction, and the dimension of the partition wall in the first spatial direction is greater than in the second.

In order to be able to use the space available behind the partition to the greatest possible extent for the evaporator, the inlet opening and the outlet opening are preferably as slots elongated in a second direction at ends of the partition extending between the storage compartment and the evaporator chamber which are spaced apart in the first direction educated.

In order to be able to suck in air from the evaporator with the lowest possible pressure drop, the axis of rotation of the radial fan is preferably oriented so that it crosses the evaporator; in this way the air can reach the radial fan in a straight line from the evaporator via an inlet extending around the axis.

If the evaporator is arranged between bypass blockers in a manner known per se, the diameter of the radial fan can be greater than the distance between the inside of the bypass blocker facing the evaporator.

In order to keep an assembly of evaporator, bypass blockers and radial fan compact, the diameter of the radial fan is preferably not greater than the distance between the outer sides of the bypass blockers facing away from one another.

Of the spatial directions mentioned above, the first preferably corresponds to the width of a body of the refrigeration device in which the storage compartment and the evaporator chamber are accommodated. The second spatial direction can in particular be the height.

The arrangement defined above is particularly suitable for a storage chamber of low height. Any storage chamber in which the height is the smallest dimension under height, width and depth, but in particular those where the height is not more than two thirds of the width or depth, can generally be regarded as such. In particular, the invention allows economical cooling of storage compartments with edge length ratios that were previously not common in refrigeration equipment because they could not be economically cooled with conventional evaporators - especially from the point of view of space utilization and energy efficiency - for example with a height that corresponds to a maximum of half the height or width. Regardless of the edge lengths, a storage compartment that is low in the sense of the present invention can also be recognized, for example, by the fact that it is filled by a single pull-out box, because even with a pull-out box, the height of all three dimensions is generally the smallest, otherwise one is faster Access to the contents of the box is not possible.

In the case of an evaporator through which air flows horizontally, but in which, unlike the conventional ceiling-mounted evaporator described above, the height is not the smallest dimension, the problem can arise that air flowing through is not evenly cooled over the entire cross-section of the evaporator, when liquid refrigerant collects in a lower area of the evaporator. In order to counteract this, the evaporator preferably comprises a plurality of evaporator modules which are successive in width and which each have identically shaped refrigerant lines connected in series and fins attached to the refrigerant lines. A small amount of liquid refrigerant is sufficient to completely fill one of the evaporator modules, and the fact that other evaporator modules further downstream in the refrigerant circuit may only contain steam does not affect the even distribution of the cooling effect over the cross section of the evaporator.

Each of these modules should extend the full height of the evaporator.

The refrigerant lines of various evaporator modules are preferably soldered to one another and / or plug-connected. In this way, the modules can be manufactured inexpensively in large numbers; lamellar evaporators with different widths can be provided at low cost by connecting different numbers of modules as required.

In order to enable the modules to be assembled quickly and easily, the connections between the refrigerant lines are preferably arranged along a single edge of the substantially cuboidal evaporator.

In order to be able to manufacture the evaporator easily and to achieve an efficient heat exchange, each lamella preferably has exactly two holes that form the refrigerant line each crosses once. This allows the refrigerant line to be bent into a hairpin shape, the lamellae to be pushed one after the other onto the pipe sections of the refrigerant line obtained thereby, and a heat-conducting contact to the lamellae to be established along the entire or substantially the entire circumference of the legs.

In order to cool the lamellae effectively, each tube section is connected to each lamella in a thermally conductive manner over at least two thirds of its circumference, preferably over its entire circumference.

The fins of each evaporator module are preferably rectangular and adjoin an adjacent block of the same evaporator module along at least one long edge and a block of another evaporator module along a short edge. In this way, one of the two pipe sections of a block can be placed in the flow shadow of the other.

To enable efficient defrosting of the evaporator, the fins should not be oriented horizontally. In order to be able to orientate the fins extending in width and height and still create an evaporator whose height is greater than the dimension in the depth direction of the body, the fins of each evaporator module should be arranged in several blocks arranged one above the other.

The distance between the fins of an evaporator module located upstream with respect to the air flow or the refrigerant flow can be selected to be greater than the distance between the fins of an evaporator module located downstream with respect to this flow. As the air gradually loses moisture on its way through the lamellar evaporator, a layer of frost grows fastest under several evaporator lamellas that are equally well supplied with liquid refrigerant on those that the air meets first on its way through the evaporator. If the distance between them is made large, the layer of frost on them can reach a great thickness before it obstructs the circulation of air to such an extent that defrosting is necessary. On the other hand, the heat absorption capacity of a lamella that is only cooled by refrigerant vapor is significantly smaller than that of one cooled by liquid refrigerant, so that if the modules connected in series have different levels of refrigerant are supplied, the fins of the evaporator module located foremost in the refrigerant flow can achieve the highest growth rate of the frost layer.

In order not to unnecessarily complicate production, the distance between the fins should be uniform within an evaporator module.

The refrigeration device preferably has a plurality of storage chambers, each of which communicates with an evaporator chamber in order to be temperature-controlled by its evaporator. Thus, each storage chamber can be regulated to its own temperature, preferably by means of its own temperature sensor, which, with a suitable design of the refrigerant circuit for individual storage chambers, can also be above the ambient temperature. In addition, a specific humidity level for each storage chamber can be achieved by regulating a temperature difference between the evaporator and the storage chamber. Mixing of differently tempered or differently humid amounts of air from different storage chambers does not take place.

Fig. 1

zwei Varianten von Lamellen eines Verdampfers;

Fig. 2

eine Draufsicht auf blockweise auf Schenkel von Rohrleitungen aufgesteckte Lamellen;

Fig. 3

ein einzelnes Verdampfermodul;

Fig. 4

einen Lamellenverdampfer mit vier in Reihe verbundenen Verdampfermodulen;

Fig. 5

einen Schnitt durch ein Kältegerät mit mehreren Lamellenverdampfern gemäß der Erfindung;

Fig. 6

einen horizontalen Schnitt durch eine Verdampferkammer des Kältegeräts aus Fig. 5; und

Fig. 7

einen zu Fig. 6 analogen Schnitt gemäß einer Abwandlung.

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

Fig. 1

two variants of fins of an evaporator;

Fig. 2

a plan view of slats slipped onto legs of pipelines in blocks;

Fig. 3

a single evaporator module;

Fig. 4

a fin evaporator with four evaporator modules connected in series;

Fig. 5

a section through a refrigeration device with several lamellar evaporators according to the invention;

Fig. 6

a horizontal section through an evaporator chamber of the refrigerator Fig. 5 ; and

Fig. 7

one to Fig. 6 analog cut according to a modification.

Fig. 1 shows two variants of lamellas 1, 1 'which are used to produce a lamellar evaporator. The lamellas 1, 1 'are thin metal sheets, typically made of aluminum, of a substantially rectangular shape. Two holes 2 are spaced from each other in a direction parallel to a long edge 3 of the rectangles; the distance d between the holes 2 is typically between a third and half the length of the edge 3. The length of a short edge 4 can be between d and 2 d.

The holes 2 of the lamella 1 are circular with a diameter which, with minimal play, corresponds to the diameter of a pipe section of a refrigerant line to be inserted in order to enable a thermally conductive contact between the pipe section and the lamella along essentially the entire circumference of the holes 2.

In the holes 2 of the lamella 1 ', the circular circumference is interrupted by notches 5, which allow the tongues 6 delimited by the notches 5 to evade when the pipe section is inserted; Thus, although a heat-conducting contact is not possible over the entire circumference of the pipe section, the pressure of the tongues 6 deflected during insertion ensures an efficient heat transfer between the pipe section and the lamella.

Fig. 2 shows a top view of partially finished evaporator modules 7a-d. Each evaporator module comprises a hairpin-shaped bent refrigerant line 8 with a first bend 9 and two straight pipe sections 10a and 10b that are integrally connected via the bend 9. A plurality of parallel lamellae 1 are each pushed onto the pipe sections 10a-b and grouped into blocks 11a-d. The extent of all blocks 11a-d in the longitudinal direction of the pipe sections 9 is the same; the number of lamellas 1 in a block 11a-d and their distance from one another can vary.

Fig. 3 shows a finished evaporator module 7. Areas of the pipe sections 10a-b, which are in the stage of Fig. 2 have remained free of lamellas are formed into semicircular second arcs 12, so that the blocks 11a-d form a stack in which long edges 3 of the lamellas of one block each face long edges of the lamellas of an adjacent block.

The block 11a adjacent to the first sheet 9 forms the bottom block of the stack. The pipe sections 10a-b meander through the blocks 11b, 11c stacked on them up to inlet and outlet connections 13, 14. One of these connections, here connection 13, is widened in order to enable the connection 14 of a structurally identical second evaporator module to be plugged in .

Fig. 4 shows four evaporator modules, denoted by 7a-d, the refrigerant lines 8 of which are connected in series by plugging into one another and soldering the connections 13, 14. The connectors 13, 14 plugged into one another lie on a straight line which runs parallel to a long edge of the approximately cuboidal evaporator 15 formed by the evaporator modules 7a-d.

The evaporator modules 7a-d can be exactly identical; in the case of Fig. 4 The evaporator module 7a differs from the other modules 7b-d in that the distance between the lamellae 1 is greater. If air flows through the evaporator 15 horizontally, in the direction of the arrows 16, during operation, the evaporator module 7a is the most upstream module in relation to the airflow, and moisture carried along in the airflow is preferably deposited on the fins of the module 7a especially when the connection 13 is used as an inlet connection and therefore the evaporator module 7a is better supplied with liquid refrigerant than the others. The increased spacing of the lamellas makes it possible to select a long time interval between two defrosting processes.

Alternatively, rapid tire build-up of the evaporator module 7a can be counteracted if the connection 14 of the module 7d is used as an inlet connection for refrigerant; then the module 7d is best supplied with liquid refrigerant. The formation of frost can vary depending on how often and how much liquid refrigerant reaches the blocks further downstream in relation to the refrigerant flow distribute to modules 7a-d. If only steam gets into the modules 7b-d, the formation of frost is so concentrated on the module 7d that it can make sense to provide an enlarged lamellar spacing in this. If the other modules also receive liquid refrigerant from time to time, frost formation takes place in these too, so that the frost is distributed over all modules and the fin spacing can be the same in all of them.

Since the connected connections 13, 14 represent the highest points of the refrigerant line in the evaporator 15, it is possible to completely fill the refrigerant line 8 of the module 7a or 7d which is furthest upstream in relation to the refrigerant flow with liquid refrigerant, even if the refrigerant lines 8 the following modules only contain steam. In this way, uniform cooling of the air flowing through is ensured over the entire cross section of the evaporator 15, even if the evaporator 15 is not completely filled.

Fig. 5 shows a section through the body 17 of a household refrigeration appliance with several storage chambers at different temperatures. The sectional plane runs near a rear wall of the body 17 through evaporator chambers 18a-c extending on this rear wall, each of the evaporator chambers 18a-c each contains an evaporator 15a-c of the type described above and forms a closed air circuit with the associated storage chamber. In the Fig. 5 Storage chambers (not shown) each have the same height as the associated evaporator chambers 18a-c and are separated from one another by intermediate floors 19 of the body 17 which are heat-insulating and which prevent air exchange between the various air circuits.

The lowest storage chamber here is a freezer compartment, the height of which roughly corresponds to its width. The height of the evaporator chamber 18a is somewhat smaller than that of the storage chamber, since part of the rear wall is occupied by a machine room 20 in the usual manner. The evaporator chamber 18a communicates with the storage chamber via an outlet opening 22a provided with an axial fan 21 in an upper region of a partition wall 24a and an inlet opening 23a in the form of a gap at a lower edge of the partition wall 24a. The evaporator 15a comprises several, here five, in the width direction of the body 17 arranged side by side evaporator modules 7 with here five blocks 11, which are flown through from bottom to top during operation.

The next higher storage chamber and its evaporation chamber 18b are much flatter; if one wanted to provide a horizontal gap and an opening as in the evaporator chamber 18a, then there would be no space to accommodate evaporator modules 7 in sufficient number and size. The number of evaporator modules 7a-d is therefore reduced in evaporator 15b, so that space remains to the right and left of evaporator 15b to provide an inlet opening 23b and an outlet opening 22b - here covered by a radial fan 25 - as well as the number of blocks 11 is reduced to match the height of the evaporation chamber 18b.

The blocks 11 themselves can be identical to those of the evaporator 15a; However, it is also conceivable to vary the number of lamellae 1 per block 11 from one evaporator 15a-c to the other in order to adapt to the capacities required in each case for the individual storage chambers. However, the smaller the number of fins, the less favorable the ratio of power to space requirement of the evaporator due to the protruding arches 9, 12. It can therefore be expedient to further reduce the number of modules 7 when the power requirement is low, as shown in the example of the evaporator 15c, so that the evaporator chamber 18c only occupies part of the width of the rear wall and the remaining width of the storage chamber 26c extends up to can extend to the rear wall. The inlet opening 23c can then be designed as a vertically elongated gap between the rear wall and an end of the partition wall 24c facing away from the radial fan 25.

Fig. 6 shows a section through a rear part of the body 17 at the level of the line VI-VI Fig. 5 . The already mentioned rear wall of the body 17 is denoted by 27, side walls by 28. The arches 9, 12 of the evaporator 15b protruding in the depth direction of the body are received in bypass blockers 29, typically molded parts made of expanded polystyrene, in order to be removed from the storage chamber via the inlet opening 23b 26b to force air sucked in between the fins of the evaporator 15b.

A suction opening 30 of the radial fan 25 lies opposite a downstream end of the evaporator 15b. The radial fan 25 comprises in a manner known per se Fan wheel 35, which rotates within a housing 31 - shown here cut open in half - about an axis 34 which is concentric to the suction opening 30 and parallel to the lamellae 1. The diameter of the suction opening 30 corresponds approximately to the edge length of a block 11 in the direction perpendicular to the lamellas or the distance between facing inner sides of the bypass blockers 29, the diameter of the housing 31 corresponds approximately to the thickness of the evaporator 15b including the bends 9, 12 or is slightly smaller than the distance between the respective outer sides of the bypass blockers 29 resting against the partition wall 24b and the rear wall 27 of the body. The fan wheel 35 carries a ring of blades 36, the inner diameter of which corresponds approximately to that of the suction opening 30; The rotation of the fan wheel 35 accelerates the air between the blades 36 radially outwards and escapes from the housing 31 via a nozzle 37 branching off in a tangential direction. The nozzle 37 crosses the partition wall 24b, its end protruding into the bearing chamber 26b forms the outlet opening 22b.

As in Fig. 5 As can be seen, the diameter of the fan 25 and in particular its suction opening is significantly smaller than the height of the evaporator 15b, which can lead to an uneven distribution of the air flow velocity over the height, especially in the evaporator module 7d which is closest to the fan 25b. This can in particular be tolerated to a certain extent if the evaporator module 7d is the module located furthest downstream in the refrigerant circuit and the other modules, which are better supplied with liquid refrigerant, contribute more to the cooling capacity. Alternatively, instead of the one fan 25b, two radial fans could also be arranged one above the other in order to achieve a more uniform distribution of the air flow at the downstream end of the evaporator 15b.

In order to be able to easily access the contents of the storage chamber 26b despite its small height, it is useful to provide a pull-out basket or pull-out box 32. In addition, a rail guide or the shape of the pull-out box 32 can ensure that it does not block the openings 22b, 23b. In the case shown here, the inlet opening 23b is flanked by a web 33 of the partition wall 24b protruding into the storage chamber 26b, and the depth of the pull-out box 32 is adapted to that of the storage chamber 26b so that a door of the storage chamber 26b can only be closed when the pull-out drawer 32 as in shown next to the web 33 on the partition 24b, but leaves the space in front of the inlet opening 23b free. In an analogous manner, the nozzle 37 protruding over the partition wall 24b prevents the door from closing when the pull-out box 32 blocks the outlet opening 22b restrict the width of the storage chamber 26b that can be used by refrigerated goods or the pull-out box 32 as little as possible.

Fig. 7 shows a modification of the body of Fig. 6 , in which the height of the freezer compartment is reduced, so that the space on the rear wall of the body is no longer sufficient to accommodate the evaporator 15a and the axial fan 21 there. The axial fan is therefore replaced by radial fan 25 with a vertical axis. So that the evaporator 15a is sufficiently flowed through over its entire width, several, here two, fans 25 are distributed over the evaporator.

REFERENCE MARK

1 1 '

Lamella

2

hole

3

long edge

4th

short edge

5

score

6th

tongue

7 a-d

Evaporator module

8th

Refrigerant line

9

arc

10

Pipe section

11 a-d

block

12th

arc

13th

connection

14th

connection

15 a-c

Evaporator

16

arrow

17th

Body

18 a-c

Evaporation chamber

19th

Intermediate floor

20th

Engine room

21

Axial fan

22 a-c

Outlet opening

23 a-c

Inlet opening

24 a-c

partition wall

25th

Radial fan

26 b, c

Storage room

27

Back wall

28

Side wall

29

Bypass blockers

30th

Suction opening

31

casing

32

basket

33

web

34

axis

35

Fan wheel

36

Shovel blade

37

jet

Claims (15)

Refrigeration device with at least one temperature zone comprising a storage chamber (26b, c) and an evaporator chamber (18a, b, c) assigned to the storage chamber (26b, c), the evaporator chamber (18a, b, c) extending in a first spatial direction along the storage chamber (26b, c) and communicates with the storage chamber (26b, c) via inlet and outlet openings (23a, b, c; 22a, b, c) spaced apart in the first spatial direction and at an outlet opening (22a, b, c) a fan (25) is arranged to suck air out of the evaporator chamber (18a, b, c) and expel it into the storage chamber (26b, c), characterized in that the fan (25) is at least one radial fan whose axis of rotation (34 ) is oriented in the first spatial direction. Refrigerating device according to claim 1, characterized in that a partition (24b) between the storage chamber (26b) and the evaporator chamber (18b) extends in the first spatial direction and a second spatial direction orthogonal thereto, and the dimension of the partition (24b) in the first Spatial direction is greater than in the second. Refrigerating device according to claim 1 or 2, characterized in that the inlet opening (22a, b, c) and the outlet opening (23a, b, c) elongated slots in a second direction at ends spaced apart in the first direction of a between the storage chamber (26b , c) and the evaporator chamber (18a, b, c) extending partition wall (24b). Refrigeration device according to Claim 1, 2 or 3, characterized in that the axis of rotation (34) of the radial fan (25) crosses the evaporator (15a, 15b). Refrigerator according to claim 4, characterized in that the evaporator (15b) is arranged between bypass blockers (29) and the diameter of the radial fan (25) is greater than the distance between the inside of the bypass blocker (29) facing the evaporator (15b). Refrigerating device according to Claim 5, characterized in that the diameter of the radial fan (25) is not greater than the distance between the outer sides of the bypass blockers (29) facing away from one another. Refrigerating device according to one of the preceding claims, characterized in that the temperature zone is accommodated in a body (17) with a height, a width and a depth and the first spatial direction is the width. Refrigerating appliance according to Claim 7, characterized in that the dimensions of the storage chamber (26b) are smaller in height than in width and / or depth. Refrigerator according to Claim 7 or 8, characterized in that the storage chamber (26b) contains a pull-out box (32). Refrigeration device according to one of claims 7 to 9, characterized in that the evaporator (15b, c) comprises several evaporator modules (7a-d) successive in the first direction, each identically shaped and serially connected refrigerant lines (8) and on the refrigerant lines (8) have attached slats (1, 1 '). Refrigeration device according to Claim 10, characterized in that each evaporator module (7a-d) extends over the entire height of the evaporator (15b, c). Refrigeration device according to claim 10 or 11, characterized in that the refrigerant lines (8) of different evaporator modules (7a-d) are soldered to one another and / or plug-connected. Refrigeration device according to one of Claims 10 to 12, characterized in that each lamella (1, 1 ') has exactly two holes (2, 2') which the refrigerant line (8) each crosses once. Refrigerating appliance according to claim 13, characterized in that the lamellae (1) of each evaporator module (7a-d) are in several blocks arranged one above the other (11a-d) are arranged and the slats (1) extend in width and height. Refrigeration device according to one of claims 10 to 14, characterized in that the distance between the fins (1) of an upstream evaporator module (7a) is greater than between the fins of a downstream evaporator module (7b-c).

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