EP3869129A1 - Refrigeration device with fin evaporator - Google Patents

Abstract

A first evaporator module (7a) of a fin evaporator comprises several blocks (11a-d) of fins (1) parallel to one another. Each lamella (1) has a first hole (2) through which a first pipe section (10) of a refrigerant line (8) extends, and a second hole (2) through which a second pipe section (10) of the refrigerant line extends (8) extends. The blocks (11a-d) adjoin one another in a first direction parallel to the surfaces of the lamellas (1). An inlet connection (13, 14) and an outlet connection (14, 13) of the refrigerant line (8) are assigned to a first of the blocks (11d); each block (11a-d) is connected to a preceding or a subsequent block via two bends (12 ) of the refrigerant line (8), and in the case of a last of the blocks (11a), the first and second pipe sections (10) are connected to one another via an elbow (9). At least one second evaporator module (7b) is arranged adjacent to the first evaporator module (7a) in a second direction parallel to the fins (1) so that air flows through it in series with the first evaporator module (7a) in the second direction (16) and a refrigerant line (8) of the second evaporator module (7b) is connected in series with the refrigerant line (8) of the first evaporator module (7a).

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 both cases, liquid refrigerant can collect at the lowest point of a refrigerant line running through the evaporator, so that circulated air, regardless of where its cross-section passes the evaporator, comes close enough to a line section filled with liquid refrigerant to be effectively cooled to become.

In recent years, many refrigeration device models have come onto the market which, in addition to the usual storage chambers, normal refrigerator and freezer, also have storage chambers for other temperature ranges. 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 has its own evaporator. While the evaporator of the upper chamber, as described above, is arranged on a rear wall of the body and flowed through vertically, the lower storage chamber is assigned a vertically elongated, horizontally flowed-through evaporator. The internal structure of the evaporator is not described. It can therefore be assumed that if the evaporator is not completely filled with liquid refrigerant, an upper area of the evaporator will only contain vapor. In contact with air flowing through, this part can heat up to above the evaporation temperature and then only insufficiently cools the air.

A well-known design of a lamellar evaporator, which is used, for example, in an installation situation such as that of the upper chamber of KR 19980018857 U can be used, comprises several blocks of mutually parallel fins, each lamella each having a first hole through which a first pipe section of a refrigerant line extends, and a second hole through which a second pipe section of the refrigerant line extends, wherein the blocks adjoin one another in the vertical direction, an inlet connection and an outlet connection of the refrigerant line is assigned to an uppermost one of the blocks, each block is connected to a preceding or following block via two bends of the refrigerant line and, in the case of a lowermost of the blocks, the first and second pipe sections are connected to one another via an bend. Since the liquid refrigerant collects in the pipe sections of the lowest block, its fins are practically kept at the evaporation temperature even when only partially filled, and air flowing vertically through the evaporator is at a temperature close to the evaporation temperature at least in this lower block chilled. However, if such an evaporator were to flow through in a horizontal direction parallel to the fins, no effective cooling of the air would be possible in a block that does not contain any liquid refrigerant.

There is therefore a need for a lamellar evaporator which, if it is arranged on edge and is flowed through horizontally, is able to cool evenly over its entire cross section, even if it is not completely filled.

The object is achieved by a lamellar evaporator with at least a first and a second evaporator module of the type described above, the blocks of which adjoin one another in a first direction parallel to the surfaces of the lamellae, the evaporator modules adjoining one another in a second direction parallel to the surfaces of the lamellae and the Refrigerant lines of the first and second evaporator modules are connected in series. If such a lamellar evaporator is installed in a refrigeration device in an orientation in which the first direction essentially corresponds to the vertical, so that the first block is the top and the last block is the bottom, then an amount of liquid refrigerant that corresponds to the capacity is sufficient of a single evaporator module to cool the air over the entire cross-section of the lamellar evaporator through which it flows.

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 second direction is preferably orthogonal to the first direction; in this way, when installed, the first direction can coincide with the vertical and the second with the width direction of the body.

In particular, the evaporator modules can form a cuboid with edges running in the first and second spatial directions. Such a lamellar evaporator can easily be manufactured in different dimensions adapted to different heights and widths of the storage chamber by varying the number of blocks in each evaporator module or the number of evaporator modules.

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

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 cuboid.

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 a lamella that is cooled by liquid refrigerant, so that if the modules connected in series are supplied with refrigerant to different degrees, the lamellae of the evaporator module located foremost in the refrigerant flow will achieve the highest growth rate of the frost layer can.

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

The invention also relates to a refrigeration device with at least one storage chamber, an evaporator chamber and a lamellar evaporator as described above, which is accommodated in the evaporator chamber.

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.

The novel structure of the lamellar evaporator described above allows the lamellar evaporator to be attached to a rear wall in a space-saving manner, even with a storage chamber of low height, instead of further reducing the usable height of the storage chamber by mounting the evaporator on the ceiling in a conventional manner.

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 a storage chamber of small height. In particular, the evaporator according to the invention also allows economical cooling of storage chambers 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 - e.g. with a maximum height half the height or width. Regardless of the edge lengths, a storage chamber 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 the smallest, otherwise quick access to it the contents of the box is not possible.

In order to keep the space requirement of the evaporator chamber communicating with the storage chamber via an inlet and an outlet small, or in order to be able to fill the space occupied by the evaporator chamber as large as possible with the lamellar evaporator, a radial fan is preferably located at the outlet is arranged, the axis of which is oriented in a direction parallel to the surfaces of the lamellae, in particular the second direction.

The outlet and the inlet can each be slots elongated in the first direction on edges of a partition between the storage compartment and the evaporation chamber which are spaced apart in the second direction.

1. a) Bereitstellen mehrerer haarnadelförmig gebogener Rohrleitungen und mehrerer jeweils zwei Löcher aufweisender Lamellen;
2. b) Aufschieben der Lamellen auf die Rohrleitungen, indem jeweils zwei Schenkel einer Rohrleitung in die zwei Löcher einer Lamelle eingeführt werden;
3. c) Gruppieren der Lamellen entlang der Schenkel zu mehreren, jeweils durch einen freien Abschnitt der Schenkel voneinander beabstandeten Blöcken;
4. d) Biegen der freien Abschnitte, um die Blöcke in einer ersten zu den Lamellen parallelen Raumrichtung aneinandergrenzend zu platzieren; und
5. e) in Reihe Verbinden der Rohrleitungen.

The invention also relates to a method for manufacturing a lamellar evaporator with the following steps:

1. a) providing a plurality of pipelines bent in the shape of a hairpin and a plurality of lamellae each having two holes;
2. b) sliding the lamellas onto the pipelines by inserting two legs of a pipeline into the two holes of a lamella;
3. c) grouping the lamellas along the legs to form a plurality of blocks which are each spaced apart from one another by a free section of the legs;
4. d) bending the free sections in order to place the blocks adjacent to one another in a first spatial direction parallel to the lamellae; and
5. e) connecting the pipelines in series.

Fig. 1

zwei Varianten von Lamellen des erfindungsgemäßen 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; und

Fig. 6

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

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 the evaporator according to the invention;

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; and

Fig. 6

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

Fig. 1 shows two variants of lamellae 1, 1 'which are used to produce the lamellar evaporator according to the invention. 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. Depending on how often and how much liquid refrigerant in the in relation to the refrigerant flow If the blocks are further downstream, the frost formation can be distributed differently over the 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 7 is therefore reduced in the evaporator 15b, so that space remains to the right and left of the evaporator 15b to provide an inlet opening 23b and an outlet opening 22b - here covered by a radial fan 25 - and the number of blocks 11 is also shown in Adjustment to the height of the evaporator chamber 18b reduced.

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 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, a fan wheel which, within a housing 31, extends around a suction opening 30 concentric axis 34 parallel to the lamellae 1 rotates. The diameter of the suction opening 30 corresponds approximately to the edge length of a block 11 in the direction perpendicular to the lamellas, that of the housing 31 corresponds approximately to the thickness of the evaporator 15b including the arches 9, 12.

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 32 or a pull-out box. In addition, a rail guide or the shape of the basket 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 projecting into the storage chamber 26b, and the depth of the basket 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 basket 32, as shown in the figure, rests next to the web 33 on the partition wall 24b. In an analogous manner, the outlet opening 22b can be shaped as a nozzle protruding over the partition wall 24b, so that the basket 32, if it blocks the outlet opening 22b, also prevents the door from closing. The free cross-sections of inlet and outlet openings 23b, 22b are each elongated vertically in the shape of a slot in order to restrict as little as possible the width of the storage chamber 26b that can be used to accommodate items to be cooled or the basket 32. <b> REFERENCE MARK </b> 1 1 ' Lamella 26b, c Storage room 2 hole 27 Back wall 3 long edge 28 Side wall 4th short edge 29 Bypass blockers 5 score 30th Suction opening 6th tongue 31 Housing + 7 ad Evaporator module 32 basket 8th Refrigerant line 33 web 9 arc 34 axis 10 Pipe section 11 ad block 12th arc 13th connection 14th connection 15 ac Evaporator 16 arrow 17th Body 18 ac Evaporation chamber 19th Intermediate floor 20th Engine room 21 Axial fan 22 ac Outlet opening 23 ac Inlet opening 24 ac partition wall 25th Radial fan

Claims (15)

Lamellar evaporator with a first evaporator module (7a) which comprises several blocks (11a-d) of mutually parallel fins (1), each fin (1) having a first hole (2) through which a first pipe section (10a) of a Refrigerant line (8) extends, and a second hole (2) through which a second pipe section (10b) of the refrigerant line (8) extends, wherein the blocks (11a-d) in a first to the surfaces of the fins (1 ) adjoin one another in parallel direction, and wherein an inlet connection (13, 14) and an outlet connection (14, 13) of the refrigerant line (8) are assigned to a first of the blocks (11d), each block (11a-d) with a preceding or a subsequent one Block is connected to the refrigerant line (8) via two bends (12) and, in the case of a last of the blocks (11a), the first and second pipe sections (10a, b) are connected to one another via a bend (9), characterized in that at least one second evaporator module (7b) is arranged adjacent to the first evaporator module (7a) in a second direction parallel to the fins (1) so that air can flow through it in series with the first evaporator module (7a) in the second direction (16), and a refrigerant line (8 ) the second evaporator module (7b) is connected in series with the refrigerant line (8) of the first evaporator module (7a). Lamellar evaporator according to Claim 1, characterized in that each tube section (10a, b) is connected in a thermally conductive manner to each lamella (1) over at least two thirds of its circumference, preferably over its entire circumference. Lamellar evaporator according to Claim 1 or 2, characterized in that the second direction (16) is orthogonal to the first direction. Lamellar evaporator according to Claim 3, characterized in that the evaporator modules (7a-d) form a cuboid with edges running in the first and second spatial directions (16). Lamellar evaporator according to one of the preceding claims, characterized in that the lamellas (1) of each evaporator module (7a-d) are rectangular and along at least one long edge (3) to an adjacent block (11a-d) of the same evaporator module (7a-d) and adjoin a block (11a-d) of another evaporator module (7a-d) along a short edge (4). Lamellar evaporator according to one of the preceding claims, characterized in that the refrigerant lines (8) of different evaporator modules (7a-d) are soldered and / or plug-connected to one another. Lamellar evaporator according to Claim 6, as far as dependent on Claim 4, characterized in that the connections between the refrigerant lines (8) are arranged along a single edge of the cuboid. Lamellar evaporator according to one of the preceding claims, 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). Lamellar evaporator according to one of the preceding claims, characterized in that the distance between the lamellas (1) within an evaporator module (7a-d) is uniform. Refrigeration device with at least one storage chamber (26b, c), an evaporator chamber (18a-c) and a lamellar evaporator (15a-c) according to one of Claims 1 to 9, which is accommodated in the evaporator chamber (18a-c). Refrigeration device according to claim 10, characterized in that the evaporator chamber (18a-c) communicates with the storage chamber (26b, c) via an inlet (23b, c) and an outlet (22b, c) and that at the outlet (22b, c) a radial fan (25) is arranged, the axis (34) of which is oriented in a direction parallel to the surfaces of the lamellas (1). Refrigeration device according to claim 11, characterized in that the outlet (22b) and / or the inlet is a slot elongated in the first direction on edges of a partition (24b) between the storage compartment (26b) and the evaporator chamber spaced apart in the second direction (16) (18b) are. Refrigerating appliance according to claim 11, characterized in that the lamellar evaporator is a lamellar evaporator according to claim 3 and that the second direction (16) is the width direction of the refrigerating appliance. Refrigerating device according to one of the preceding claims, characterized in that the first direction is the vertical. Method for manufacturing a lamellar evaporator with the steps: a) providing a plurality of pipelines (8) bent in the shape of a hairpin and a plurality of slats (1) each having two holes (2); b) sliding the lamellas (1) onto the pipelines by inserting two pipe sections (10) of a pipeline (8) into the two holes (2) of a lamella (1); c) grouping the lamellas (1) along the pipe sections (10) to form a plurality of blocks (11) which are each spaced apart from one another by a free section of the pipe sections (10); d) bending the free sections in order to place the blocks (11) adjacent to one another in a first spatial direction parallel to the lamellas (1); and e) connecting the pipes (8) in series.

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