WO2002099344A1

WO2002099344A1 - Refrigerating device and refrigeratory therefor

Info

Publication number: WO2002099344A1
Application number: PCT/EP2002/005804
Authority: WO
Inventors: Roland Maier
Original assignee: BSH Bosch und Siemens Hausgeräte GmbH
Priority date: 2001-06-01
Filing date: 2002-05-27
Publication date: 2002-12-12
Also published as: PL367236A1; PL199573B1; EP1397624A1; DE10126818A1; CN1513102A; CN1289883C

Abstract

A refrigeratory for a refrigerating device comprising a refrigerating agent channel (4) which is guided between two side walls (2, 3). At least one of the side walls (3) is made of a non-rigid bending material which can be adapted internally to a wall (10) on which the refrigeratory (1) is mounted.

Description

Refrigeration device and evaporator therefor

The present invention relates to a refrigeration device and an evaporator for a refrigeration device, in particular a so-called cold-wall evaporator.

Such evaporators are usually represented by free-hanging or foamed roll bond or tube-plate systems.

The expenditure for the production of such evaporators is not insignificant. Especially with foamed-in evaporators that are arranged in contact with a wall of the inner refrigerated goods container of the refrigeration device, an extremely high evenness of the evaporator wall is required in order to achieve intimate contact with the wall of the refrigerated goods container and thus good heat transfer over the entire evaporator surface. Even an unevenness of a few tenths of a millimeter prevents such intimate contact. Corresponding flatness requirements naturally also apply to the refrigerated goods container wall on which the evaporator is arranged.

An object of the present invention is to provide a refrigeration device or an evaporator for a refrigeration device, which can be manufactured inexpensively and without high demands on the dimensional accuracy, in particular the evenness, of the evaporator, and which nevertheless have an intimate contact and a highly effective heat exchange with the Allow wall of a refrigerated goods container.

The object is achieved according to the invention by an evaporator with a coolant channel guided between two side walls, in which at least one of the side walls, which is provided for contact with the wall of the refrigerated goods container, is formed from a flexible material or a refrigeration device equipped with such an evaporator , Such an evaporator wall is able to adapt to the shape of the refrigerated goods container wall and to follow its course in intimate contact, even if the refrigerated goods container wall is not exactly flat.

Such a flexible wall can be made from a plastic film, preferably from a weldable plastic material. Such a plastic material has a lower specific thermal conductivity than metals conventionally used for such an evaporator wall; however, since the film has no mechanical support function, it can be thinner than conventional metal walls and thus have a comparable or even higher heat transfer coefficient.

The refrigerant channel inside the evaporator is expediently formed by a pipeline, and the evaporator contains a heat-transferring fluid in thermal contact with the pipeline. Such a fluid can perform convection movements during operation of the evaporator, as a result of which highly efficient heat transfer between the side wall and the coolant channel is possible even over greater distances.

The two side walls of the evaporator can be in one piece and tightly connected at their common edge; this allows the use of different materials for the two walls, e.g. a thin-walled film without inherent rigidity for that side wall of the evaporator which is intended for contact with the wall of the refrigerated goods container, and a rigid, thick-walled film or a plate for the opposite wall.

The production is simplified if the side walls are formed in one piece by a bag or hose. In this case, the evaporator is easy to manufacture by using a tube to first form it into a bag by closing an opening and then inserting the pipeline through the remaining opening of the bag and filling the fluid and then also sealing this opening.

In order to prevent such an evaporator with at least one limp wall from deforming in an uncontrolled manner under the weight of the fluid contained therein and for example the fluid to collect in the lower region of the evaporator and the upper region to dry out, the side walls are expediently at a distance from them Edge connected locally so that they can not move far enough apart to hold all of the filled fluid in the lower area of the evaporator. In order to fix the pipeline within the evaporator, local connections between the side walls are expediently in each case at one Inside formed by bends in the pipeline. A complementary local connection on the outside of the bend prevents the pipeline from slipping in the opposite direction.

Preferably, at least one elongated local connection extends across the side walls crossing the pipeline. Such an elongated connection is preferably oriented horizontally and forms a tight separation between two chambers for the fluid. In this way, the evaporator is divided into a plurality of sections lying vertically one above the other, between which no fluid exchange is possible. In this way it is excluded that the fluid can collect in a lower area of the evaporator and an upper area falls dry.

An aqueous medium, in particular a brine solution, is preferably used as the heat-transfer fluid. To protect the pipeline, the brine can contain corrosion-preventing additives.

A refrigeration device according to the invention has an evaporator of the type described above in intimate contact with the wall of its refrigerated goods container. Contact can be ensured by gluing the evaporator to the wall.

In general, a freezing point below the operating temperature of the evaporator will be chosen for the fluid, so that convection of the fluid and thus an effective heat exchange is always possible.

However, it can be advantageous to select the freezing point of the fluid below a target temperature of the refrigerated goods container, but above a lowest possible temperature of the refrigerant, which generally depends on the nature of the refrigerant and the design of the refrigeration device of the refrigeration device. Such a selection of the freezing point leads to a throttling of the cooling capacity due to freezing and loss of the convection movement of the fluid when the target temperature of the refrigerated goods container is undershot, and can thus prevent unwanted hypothermia. A particularly practical application for this is a combination device with at least two refrigerated goods containers provided for different storage temperatures. If in such a device an evaporator of the type described above to that for the higher Storage temperature provided refrigerated goods container is arranged and the freezing point of the fluid lies between the storage temperatures provided for the two refrigerated goods containers, the evaporators of both refrigerated goods containers can be supplied in series with the same coolant flow, and as soon as the target temperature of the warmer refrigerated goods container is undershot and the fluid in its evaporator freezes, its heat transfer efficiency decreases, so that the available cooling capacity essentially benefits the refrigerated goods container with the lower storage temperature.

Further features and advantages of the invention emerge from the following description of exemplary embodiments with reference to the attached FIGS.

1 shows a front view of an evaporator according to the invention in a first embodiment;

FIG. 2 shows a section through the evaporator from FIG. 1 along the line II-II from FIG. 1;

3 shows a second embodiment of the evaporator in a front view analogous to FIG. 1;

FIG. 4 shows a section through the evaporator from FIG. 3 along the line IV-IV from FIG. 3;

FIG. 5 shows a detail of an evaporator according to a modification of FIG. 3;

6 is a front view of a third embodiment of the evaporator;

7 shows a horizontal section through a refrigeration device equipped with an evaporator according to the invention; and

Fig. 8 is a partial vertical section through a refrigerator with two refrigerated goods containers, which are equipped with evaporators according to the invention.

Fig. 1 shows a front view of an evaporator according to a first embodiment of the invention. Fig. 2 shows the same evaporator mounted on a wall of the refrigerated goods container of a refrigerator. The evaporator 1 is essentially constructed from two flexible foils 2, 3 made of a weldable plastic material, between which a rigid pipeline 4, preferably made of highly heat-conducting metal, is arranged for a refrigerant. The pipeline has a meandering or zigzag-like course, with straight vertical sections connected by 180 ° bends.

The foils are tightly connected to one another by a circumferential weld at their edge 5. Supply and discharge connections 6, 7 for the refrigerant are led out in an upper section of the edge 5 between the two foils 2, 3.

Three elongated local connections 8 in the form of weld seams extend from one side to the other over the entire width of the evaporator and cross the pipeline 4 several times. They divide the surface of the evaporator into four closely delimited sections 9 of essentially the same size contain approximately equal amounts of a brine serving as heat exchange fluid. In the area of the elongated connections, the foils 2, 3 adhere firmly to the pipeline 4, so that slipping of the foils 2, 3 in relation to the pipeline 4, which could lead to obstructions when installing the evaporator, is largely ruled out.

Depending on the size of the evaporator 1, more or less elongated local connections can also be provided.

As can be seen in the section of FIG. 2, one of the two foils, foil 3, lies essentially over the entire surface of a rear wall 10 of the refrigerated goods container of a refrigeration device. The film 3 is expediently glued to the rear wall 10. This can be accomplished in a simple manner by setting up the refrigerated goods container with a horizontally oriented rear wall 10, coating the rear wall and / or the film 3 with adhesive, and placing the brine-filled evaporator 1 on the rear wall 10. Since the film 3 is thin-walled and flexible, the weight of the evaporator 1 alone is sufficient to ensure that the film 3 at least in the area of the sections 9 clings tightly to the rear wall 10 and thus forms an intimate contact with the latter, even if the Back wall 10 is not exactly flat. In order to bring the film 3 into contact with the rear wall 10 also in the area of the connections 8, it is sufficient to press it slightly against the wall 10. The pipe 4 lies so close to the rear wall 10 that it is practically separated from it only by the thickness of the film 3. Therefore, in the areas where the pipe 4 touches the rear wall 10 via the film 3, an efficient heat exchange between the pipe 4 and the refrigerated goods container is possible. The remaining surface of the pipeline 4 cools the brine enclosed in the sections 9 and thus causes a convection movement which leads to the cooled brine flowing downward and thereby moving away from the pipeline 4 and being distributed over the surface of the sections 9. In this way, a highly effective cooling of the sections 9 is achieved over their entire surface, although the thermal conductivity of the brine itself is worse than that of a metal.

FIG. 3 shows a modification of the evaporator from FIG. 1, in which the connections 8 are not designed as a continuous weld seam, but rather as a multiplicity of spot welds which allow an exchange of brine between the sections 9 'delimited by the connections 8' , In order to ensure that the brine cannot collect in the lowermost section 9 'and therefore the uppermost section 9' contains practically no brine, the height h of the sections is not constant, as in the embodiment in FIG. 1, but takes it from below towards the top and is selected such that essentially the same thickness d of the sections results in the weight of the brine in all sections 9 ', as shown in FIG. 4.

FIG. 5 shows a detail of a modified version of the evaporator from FIG. 3. Here, in the upper region of the rim 5, a filler neck 11 for the brine is formed from two extensions of the foils 2, 3 that are partially welded together. This variant allows the foils 2, 3 to be welded to one another in the region of the edge 5 and the connections 8 ′, and only then, preferably after the evaporator has been installed on the rear wall 10, to be filled in with the brine. This has the advantage that the evaporator, as long as it has not yet been installed, has only a low weight, which is for the most part the weight of the pipeline 4. There is therefore no danger that improper handling will lead to deformation of the pipeline 4 before installation. The attachment of the evaporator to the rear wall 10 is also facilitated, since the brine, if it has not yet been filled in, cannot cause the foils 2, 3 to slide undesirably with respect to the pipeline 4 due to their weight. Such a filler neck can of course also be provided on the evaporator of FIG. 1, but here each individual section 9 must be provided with such a neck.

6 shows a third embodiment of the evaporator. It differs from the ones described above on the one hand in the orientation of the pipeline 4, which here is predominantly composed of horizontal straight sections 13 connected by 180 ° bends 12. Elongated connections 9 "between the foils 2, 3 extend in the vertical direction and each consist of a plurality of individual welding spots which are arranged above and below each horizontal section in order to prevent the foils 2, 3 from slipping in the vertical direction. Further local Connections 14 are each provided on the inside of the bends 12 to prevent the foils from slipping sideways to the outside, complementary connections 15 are located opposite them on the outside of the bends 12. These connections 14, 15 are also designed as welding points or seams These connections 8, 14, 15 offer a high degree of security against slipping of the foils 2, 3 against the pipeline 4 even when the evaporator is filled with brine.

Such local connections on the inside and outside of the pipe bends can of course also on an evaporator with horizontally oriented pipe sections as in Figs. 1 and 3 can be provided.

Fig. 7 shows a horizontal section through a refrigerator according to the invention. Its box-shaped housing essentially consists of an outer housing wall 15 made of sheet metal, and a refrigerated goods container 16 arranged therein, which is, for example, drawn in one piece from plastic, the housing wall 15 and the refrigerated goods container 16 delimiting a space 17 between them. In the intermediate space 17, the evaporator 1 is arranged in intimate contact with the rear wall 10 of the refrigerated goods container 16. After mounting the evaporator 1 on the rear wall 10 and joining together the outer housing wall 15 and the refrigerated goods container 16, the intermediate space 17 has been filled with a heat-insulating foam material 18 which also extends over the entire rear side of the evaporator 1. 8 shows a partial section through the upper region of the rear wall of a refrigerator with freezer compartment 20 and refrigerator compartment 21. Both compartments 20, 21 are provided on their rear walls with evaporators 1, 1 'as shown in FIGS. 1 and 2, 3 to 5 or 6, equipped. The pipes of both evaporators 1, 1 'are connected in series so that the same coolant flow flows through them. The composition of the brine is different in the evaporators 1, 1 ', specifically for the evaporator 1' of the cooling compartment 21 so that its freezing point is at most slightly below the freezing point of pure water, the freezing point of the brine in the evaporator 1 is in contrast considerably deeper. If a flow of coolant flows through the two evaporators, the temperature of which lies below the freezing point of the brine in the evaporator 1 ', this brine only remains liquid if a strong heat input from the cooling compartment 21 prevents it from freezing. If this is not the case, an ice layer forms around the pipeline of the evaporator 1 ', which isolates the pipeline from a possible portion of the brine which has remained liquid and thus reduces the convection of the brine in the evaporator 1'. The lower the heat input into the cooling compartment 21, the thicker this layer of ice. In this way, the cooling capacity of the evaporator V automatically adapts to the cooling capacity requirement of the compartment 21, without the need for sensors, control circuits or switching valves. The cooling capacity thus not queried when the refrigerant passes through the evaporator 1 'is then available to the evaporator 1 of the freezer compartment 20.

If regulation of the cooling capacity of the evaporator via partial or complete freezing of the brine contained in it is provided, it is important that the film 2 facing away from the wall of the refrigerated goods container on which the evaporator is mounted is not taut, but rather as in Figs. 2, 4, deviating from the cross-section in the form of a segment of a circle, hangs somewhat limply, so that the brine can expand in the evaporator when freezing, without this leading to deflection and partial detachment of the film 3 from the refrigerated goods container wall.

Claims

claims

1. Evaporator (1) for a refrigerator with a between two side walls (2, 3) guided refrigerant channel (4), characterized in that at least one of the side walls (3) is formed from a pliable material.

2. Evaporator according to claim 1, characterized in that the one side wall (3) is made of a plastic film.

3. Evaporator according to claim 1 or 2, characterized in that the refrigerant channel is formed by a pipe (4), and that the evaporator (1) contains a heat-transferring fluid in thermal contact with the pipe.

4. Evaporator according to claim 1, 2 or 3, characterized in that the side walls (2, 3) in two parts and at their edge (5) are tightly connected.

5. Evaporator according to one of the preceding claims, characterized in that the side walls are formed in one piece by a bag or hose.

6. Evaporator according to one of the preceding claims, characterized in that the side walls (2, 3) have local connections (8, 14, 15) at a distance from their edge.

7. Evaporator according to claim 6, characterized in that the pipeline (4) has bends (12) and that a local connection (14) between the side walls (2, 3) is formed in each case on an inside of the bends (12).

8. Evaporator according to claim 7, characterized in that a local connection (15) is formed on the outside of a bend (12).

9. Evaporator according to one of claims 6 to 8, characterized in that at least one elongated local connection (8, 8 ', 8 ") crosses the pipeline (4) over the side walls (2, 3).

10. Evaporator according to claim 9, characterized in that the at least one elongated connection (8) is oriented essentially horizontally and two

Separates chambers (9) for the fluid tightly.

11. Evaporator according to one of claims 3 to 10, characterized in that the fluid is an aqueous medium, in particular a brine solution.

12. Evaporator according to claim 11, characterized in that the fluid contains at least one corrosion-inhibiting additive.

13. Refrigerator with an evaporator (1, 1 ') according to any one of the preceding claims, characterized in that the evaporator between a wall

(10) a refrigerated goods container (16) and an outer housing wall (15) of the refrigerator are arranged in intimate contact with the wall (10) of the refrigerated goods container (16).

14. Refrigerating appliance according to claim 13, characterized in that the evaporator (1, 1 ') with the wall (10) of the refrigerated goods container (16) is glued.

15. Refrigerating appliance according to claim 13 or 14, characterized in that an intermediate space (17) between the evaporator (1) and the outer housing wall (15) is foamed.

16. Refrigerating appliance according to one of claims 13 to 15, characterized in that the fluid has a freezing point below the operating temperature of the evaporator (1).

17. Refrigerating appliance according to one of claims 13 to 16, characterized in that the fluid has a freezing point below a target temperature of the refrigerated goods container but above a lowest possible temperature of the refrigerant.

8. Refrigerating appliance according to one of claims 13 to 17, characterized in that it is a combination device with at least two refrigerated goods containers (20, 21) provided for different storage temperatures, that the evaporator (1) according to one of claims 1 to 12 on the for higher storage temperature provided refrigerated goods container (21) is arranged and the

Freezing point of the fluid lies between the storage temperatures provided for the two refrigerated goods containers (20, 21).