EP2638337B1 - Evaporator - Google Patents

Description

The invention relates to an evaporator for a refrigeration appliance, in particular a domestic refrigeration appliance, with a pipe through which a refrigerant can flow with an inlet and an outlet opening, wherein the tube has U-shaped deflections with legs of pipe sections running parallel to each other and straight and wherein the pipe is in Passage openings of fins is stored.

Depending on the cooling principle, refrigerators and freezers often include an evaporator for expanding the cooling medium and for cooling a cold room. This evaporator tends to icing. In no-frost devices, localized supply of energy to the icing-prone areas of the evaporator causes defrosting of the ice without bringing the entire refrigerator to defrost temperature. A corresponding defrosting device is off DE 11 2004 002 258 T5 in which a defrosting heater is inserted into a through hole of the fins of the evaporator. DE 31 45 445 shows another defrost heater in contact with the heat exchange fins.

The layout DE 10 00836 shows an evaporator comprising a cooling coil around which a heating cable is wound and is considered as the closest prior art over the subject of claim 1.

The publication WO 2008/001526 A1 shows an evaporator with a fin element. The fin element has slots for a heater.

The patent US 3,285,334 shows a heat exchanger comprising lamellar elements. The lamellar elements have notches in which a tube is clamped.

The publication WO 2007/045677 A1 shows an evaporator with a tube and fins. Furthermore, a resistance element is provided, which runs parallel to the tube.

A disadvantage of the known solutions is first the attachment of the heater to the evaporator, since there is a certain distance in known solutions. Also, the evaporator in the manufacturing process should be easy and inexpensive to produce and the heater should be easily removed in case of service.

This object is achieved with an evaporator for a refrigeration device of the type mentioned above in that a defrost heater along at least a portion of the straight pipe sections is provided and the defrost heater is guided and stored in the passage openings of the slats.

Inventively, an evaporator is provided for a refrigerator having a refrigerant-flowable tube with an inlet and an outlet opening according to independent claim 1.

This results in an immediate vicinity of the heater to the tube and both components are held with a guide, namely the passage opening, which significantly reduces the mechanical complexity of storage. Compared to versions with a spatially separate heating can be omitted by this structure, a separate heat conduction.

In addition, the defrost heater can be removed and / or mounted on one of the sides of the deflections of the evaporator. It can be easily assembled in the production process and is easy to remove even for service purposes.

Preferably, the defrost heating has at least one U-shaped deflection, which is associated with a U-shaped deflection of the tube and the defrost heater extends along a leg of the tube in a first radial direction of the tube and along the other leg of the tube in a second radial Direction of the pipe. In this case, the second radial direction differs by at least 90 ° from the first radial direction. By this construction (as will be explained in detail later) a contour of the passage opening is made possible, which keeps the tube in its defined desired position even if the defrost heating is not introduced, as may occur, for example, during the manufacturing process.

More preferably, the second radial direction differs from the first radial direction by 180 °. Since the portions of the pipe heater are on respective opposite sides of the cooling tube, the guidance of the tube is improved in the passage openings. In addition, in the event that the defrost heater is above and below the pipe, condensate drain better than if it were adjacent to (horizontally) the pipe.

In particular, the defrost heater has meandering a plurality of U-shaped baffles associated with U-shaped baffles of the tube, and the defrost heater extends along the straight legs in different radial directions of the tube and the radial directions are at respective adjacent legs of the tube differently. This will be the leadership of Tube in the passage openings in total, so over several periods of the deflections out, improved.

In addition, the defrost heater is an electrical resistance heater, as this can be produced and installed at low cost and space-saving.

Preferably, the defrost heater meandering on a plurality of U-shaped turns, which are all in one plane. This does not exclude that further turns may not lie in this plane. In this way, the defrost heater is a flat assembly that can be stacked well in the manufacturing process. Since the defrost heater does not have a very high flexural rigidity, it is advantageous that it does not have an excessively complex shape.

Since it was recognized that especially the input-side pipe sections are particularly affected by icing, it is sufficient to attach a corresponding heater to these.

An appropriate refrigerator and / or freezer includes an evaporator and a controller or controller for activating the defrost heater and thus for defrosting the evaporator. So a no-frost cooling unit is provided and for de-icing, the entire unit does not have to be heated to temperatures above zero degrees.

The object of the invention and its developments are described below with reference to drawings.

Fig. 1

eine sphärische Ansicht des Verdampfer mit der Abtauheizung,

Fig. 2

die Abtauheizung vor der Einführung in den Verdampferkörper,

Fig. 3

eine Zwischenstellung der Einführungsbewegung bei der Montage,

Fig. 4

eine Lamelle in der Draufsicht und

Fig. 5

bis Fig. 7 alternative Ausführungen der Lage der Abtauheizung relativ zum Verdampferrohr.

Show it:

Fig. 1

a spherical view of the evaporator with the defrost heater,

Fig. 2

the defrost heating before the introduction into the evaporator body,

Fig. 3

an intermediate position of the insertion movement during assembly,

Fig. 4

a slat in the plan view and

Fig. 5

to Fig. 7 alternative embodiments of the position of the defrost heater relative to the evaporator tube.

Fig. 1 shows an evaporator, as used, for example, in a compressor refrigerator. In this cooling principle, a refrigerant is compressed by a compressor, whereby it is heated. This heat is released via a capacitor to the environment. Subsequently, the (liquid) coolant is passed to reduce the pressure via a throttle and relaxed in this way. In this case, the refrigerant evaporates and there is evaporation cold, which is discharged via an evaporator to a surrounding medium. This ambient medium is usually the air in the space to be cooled, which is passed either by the convection principle or fan assisted by the evaporator. Subsequently, the refrigerant is supplied to the compressor again, whereby the refrigerant circuit is closed. According to Fig. 1 the current of the ambient medium is shown with the arrows K.

The evaporator is in the present case designed as a tube evaporator. In this case, a tube with an inlet opening 5 and an outlet opening 7 is used. This tube 2 has a plurality of turns or U-shaped deflections. In this case, each U-shaped deflection comprises two legs 10 and 10 ', which are designed as straight and parallel pipe sections and at the base there is a deflecting element 12. This deflecting element can be formed in the simplest case by bending the tube. Alternatively, a separate semicircular curved element with the legs 10 and 10 'connected and in particular soldered be. Since both ends of the legs are deflected in a U-shape, the result is a kind of position of adjacent parallel legs. The legs are not in a plane, but every other leg is an amount of almost twice the pipe diameter corresponds to the top - ie according to Fig. 2 in z-direction - offset. Two of these layers are superimposed so that the outlet opening 7 of the inlet opening 5 is adjacent.

In the region of the deflections 12 lamellae 20 are provided with passage openings 25 and 30. During assembly of the evaporator 1, the already correspondingly bent tube 2 is moved by a movement in the y-direction against the slats. The lamellae have the task in use of the evaporator to keep the bent tube 2 in its desired position and thus to give the evaporator mechanical stability against shock or vibration. Furthermore, the lamellae are directly in contact with the tube, so that a good heat exchange is possible and so serve the cooled surfaces of the lamellae cooling the air to be cooled. In principle, for reasons of strength, one blade at a time is sufficient for both areas of the deflections. For reasons of improved heat transfer are at the front end (see Fig. 3 ) but five parallel spaced slats 20 in use. The fins 20 of the two ends are identical. Further, on the left side, ie in the region of the incoming air flow, a plurality of further fins 15, which are cooled by two U-shaped deflections and on the one hand improve the heat transfer from the air to be cooled to the evaporator body and also to reduce the flow rate be used.

In the slats 20 according to Fig. 4 Upper passage opening 25 are used, whose size is dimensioned so that a U-shaped deflection of the pipe can be inserted through it. The lower passage openings 30 also include areas for the passage of U-shaped deflections, but are extended in different directions, so that through these passage openings 30 in addition, the defrost heater can be introduced. So that's how it turns out Fig. 3 gives the region 54 of the defrost heater 50 above (in the z-direction) of the associated pipe section 10 and the portion 54 'of the defrost heater 50 below the pipe section 10'. The passage openings 25 and 30 are each circumferentially closed.

By introducing the defrost heater 50 through the same passage openings 30 of the fins 20 as the corresponding pipe sections 10 and 10 ', it follows that the defrost heating is applied directly to the corresponding pipe sections, which causes the best defrosting effect.

FIGS. 5 to 7 show different variants in which the defrost heater can abut a corresponding U-shaped deflection of the pipe. The figures are shown from a viewing angle in the y-direction in the evaporator body, wherein the two larger circles represent sections through the tube and the smaller interconnected circles is a section through the defrost heater. Fig. 6 stands for the installation situation according to the main embodiment and is rotated by about 30 ° and in this case the defrost heater is in different directions to the rectilinear pipe sections 10 and 10 'at. Alternatively, a variant of a passage opening could be rectangular, so that, according to Fig. 5 , the pipe heater is in each case on the same side of the tube.

The execution of Fig. 6 is advantageous in a production process, in which first the tube is plugged together with the lamellae and then, for example, in an immersion bath, is soldered together. It can be seen from the geometry of the passage opening 30 of the lamella 20 that, due to its shape, the U-shaped deflection of the tube into the x and z directions is well guided. In the execution of the Fig. 5 Although the defrost heater is also ideally located on the pipe, the defrost heater can only be installed after soldering. That is, the pipe has in the execution of Fig. 5 at the time of soldering in z'-direction a certain play, so that can not be made in the manufacturing process without further ado that it remains at its desired position. Even if no connection, such as soldering, is made from the fins to the pipe, so is the concept of 6 and 7 advantageous since vibrations in the x or z direction of the tube are absorbed by the lamellae and not by the defrost heater, which optionally has a vulnerable plastic sheath.

According to Fig. 7 an alternative embodiment of the defrost heater is shown. In this case, the lamella would have an elongate passage opening adapted to the outer dimensions of the pipe deflection, with an enlargement on the right side for a part the pipe heating. Even so, the bent pipe is well guided in its position in the x and z directions during the manufacturing process and before the pipe heater is inserted.

Reference numerals:

1

Evaporator

2

pipe

5

inlet port

7

outlet

10, 10 '

Straight pipe sections of the inlet side

12

deflections

16, 16 '

outlet-side straight pipe sections

20

lamella

25

upper passage opening

30

(lower) passage opening

50

defrost heater

54.54 '

straight sections

56

deflections

Claims (8)

1. Evaporator (1) for a refrigeration appliance, in particular a domestic refrigeration appliance, having a pipe through which a refrigerant can flow, said pipe having an inlet (5) and an outlet opening (7), wherein the pipe has U-shaped baffles with arms made of pipe sections (10, 10', 16, 16') running parallel to each other and in straight lines and wherein the pipe is supported in through-flow openings (30) of plates (20), wherein a defrost heater (50) is provided along at least one part of the straight-line pipe sections (10, 10') and the defrost heater (50) is conducted and supported in the through-flow openings (30) of the plates (20), characterised in that the straight-line pipe sections (10, 10') which are adjacent to the inlet opening (5) according to the refrigerant flow are provided with the defrost heater (50) and the straight-line pipe sections (16, 16') which are adjacent to the outlet opening (7) according to the refrigerant flow are not provided with a defrost heater.
2. Evaporator (1) according to claim 1, characterised in that the defrost heater (50) can be removed from and/or mounted on the evaporator (1) on one of the sides of the baffles (12).
3. Evaporator (1) according to one of the preceding claims, characterised in that the defrost heater (50) has at least one U-shaped baffle (52), which is associated with a U-shaped baffle of the pipe and the defrost heater (50) extends along an arm (10) of the pipe in a first radial direction of the pipe and extends along the other arm (10') of the pipe in a second radial direction of the pipe, and the second radial direction differs from the first radial direction by at least 90°.
4. Evaporator according to claim 3, characterised in that the second radial direction differs from the first radial direction by 180°.
5. Evaporator (1) according to one of the preceding claims, characterised in that the defrost heater has a plurality of U-shaped baffles (52) in a meandering manner which are associated with U-shaped baffles of the pipe and the defrost heater extends along the straight-line arms in differing radial directions of the pipe and the radial directions are different in each case with adjacent arms of the pipe.
6. Evaporator according to one of the preceding claims, characterised in that the defrost heater (50) is an electrical resistance heater.
7. Evaporator according to one of the preceding claims, characterised in that the defrost heater has a plurality of U-shaped coils which all lie in one plane.
8. Refrigerator and/or freezer having an evaporator (1) according to one of claims 1 to 7 and an open- or closed-loop control for activating the defrost heater and thus for deicing the evaporator.

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