DE1601053A1 - Cooling device - Google Patents

Description

Dr.-ing. Diploma Phys. OSKAR KÖNIG Patent Attorney 1 R Π Ϊ fl R Ί

Deutsche Bank AG Stuttgart ■

Telephone: (0711) 6285 61 account number 89/00300

Telegram: Koenigpat 7000 STUTTGART-I, Klüpfelstraße 6 Postscheck Stgt. 84919

P.O. Box 51

1765

C-H

Gottlob Bauknecht electric motor construction

Stuttgart

Cooling device.

Additional patent. ...... (patent application ......)

to

Main patent ........ (patent application B 95 406 Ia / 17a)

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The main patent (patent application B 95 406 Ia / 17a)

relates to a method for cooling cold rooms of cooling devices, in particular refrigerators or the like, and a cooling device for carrying out the method.

The cooling device of the main patent (the main patent application) has at least one evaporator which is arranged in a separate cold chamber in which there is a flowable fluid, preferably air, that cannot generate frozen precipitate in the cold chamber. The evaporator draws off during the cooling phase the cooling space heat via at least one expediently large cooling wall, which is a partition between the interior of the cold chamber and the cold room. the Cooling wall is designed and the evaporator in relation on the cooling wall so arranged and designed that during the cooling phases the to the interior of the cooling space adjacent cooling surface of the cooling wall has approximately the same temperatures and a considerable temperature difference between the evaporator and the cooling surface. The present invention aims at one in particular to create advantageous design of the cold chamber and in particular the cooling wall, through which during the cooling phases an approximately uniform temperature of the cooling surface with simultaneous generation of a considerable temperature difference is brought about between the evaporator and the cooling surface. A particular aim of the present invention The idea here is to design the cold chamber and in particular the cooling wall in such a way that the cooling chamber is cooled and .the defrosting of any frost on the cooling surface takes place with little inertia, i.e. that the cooling

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system overall has a low inertia, so that after the end of a shutdown phase of the refrigeration machine (downtime), cooling starts quickly and effectively and after the end of each such cooling phase, the temperature of the cooling surface even without the supply of external energy increases in order to thaw any frozen precipitation on it accordingly quickly, so that complete defrosting during each shutdown phase of the refrigeration machine that occurs between two cooling phases Any frozen food on the cooling surface. Precipitation succeeds in a simple way.

To solve this problem - with a cooling device, preferably a refrigerator or the like, with at least one cold room, preferably a normal cold room, which is assigned a separate cold chamber in which there is at least one evaporator of a refrigeration machine and a fluid pluid is located in the The cold chamber cannot produce frozen precipitation, the cold chamber and the cooling chamber being a common, have a cooling wall designed as an intermediate wall, the cooling surface of which faces the cooling space from the evaporator over a considerable temperature gradient during the cooling phases is cooled, according to the main patent. .

(Patent application B 95 406 Ia / 17a), proposed according to the invention, that at least a portion of the cooling wall of the cold chamber having the evaporator at least a thin thermal conductive layer of a material with good thermal conductivity, preferably an aluminum layer, and that at least one further layer of the cooling wall made of a substance of low thermal conductivity and less Heat capacity exists, the layer thickness of which

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preferably significantly greater than the thickness of the heat-conducting layer is. Due to the thin thermal conductive layer, the Temperature uniformity of the cooling wall improved without that their heat capacity is disruptively increased. On the advantages of the even temperature of the cooling surface is in the main patent (main patent application) indicated: reading.

Due to the aforementioned new design of the cooling wall a particularly rapid, even cooling of the cooling surface is achieved after the start of each cooling phase. After the start of each shutdown phase, the cold chamber and the evaporator heat up rapidly, because, due to the low heat capacity of the cooling wall, a rapid heat balance even without additional heating takes place between the cold room and the cold chamber and there is no frost in the cold chamber. Through this also the liquid refrigerant in the evaporator at the beginning of a shutdown phase of the refrigeration machine evaporates quickly and so the evaporator is emptied of liquid refrigerant within a short time. The emptying can, as described in the main patent, be accelerated by adding heat to the evaporator " from in a capillary tube designed as a compressor machine Cooling machine located warm heat medium is supplied. The supply of this heat ceases some time when the liquid refrigerant in the capillary tube is due to its heat release has cooled down to the temperature of the cold room. The interior of the cold chamber is expediently one in one Outer wall of the cooling chamber provided cavity, so that the cold chamber at the same time a heat trap for through the thermal insulation of the cold room is heat penetrating from the outside, which is already trapped in the cold chamber

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and is discharged by means of the evaporator without it being able to penetrate into the cooling space. This shows how described in the main patent, the cooling and defrosting conditions still, further improved.

The heat-conducting layer is preferably one on the interior the cooling wall layer adjacent to the cold chamber. The amount withdrawn from the cold room during the cooling phases Heat is partly in this layer in the vicinity of the evaporator or if the evaporator is in contact with this layer is, 'partly fed directly to the evaporator, while the rest of the heat through the Pluidum located in the cold chamber by means of heat conduction and convection of this iluidum is transferred to the evaporator.

Further features of the invention are described or illustrated in the following description, the claims and the drawing, it being understood that the invention can be implemented in numerous other embodiments. Exemplary embodiments of the invention are shown in the drawing.
Show it:

3? Ig. 1 shows a section of a cold chamber and an adjoining cold room of a refrigeration device in FIG longitudinal section,

Pig.2 a variant of the Pig. 1.

In Pig. 1 is a longitudinally cut section of a Refrigerator shown. Except for the novel cold chamber, this refrigerator can be any one known per se Have type of construction. For example, the refrigerator can advantageously have a cooling room and a Lorma! Cooling room

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have whose evaporators are connected in series, the evaporator of the normal cold room in a cold chamber and the evaporator of the freezer compartment is arranged in this freezer compartment in a manner known per se.

In the variant shown in Fig. 1, a normal cold room of a refrigerator (not shown in detail) is denoted by 100, in the rear wall of which a narrow, closed cavity 1Ο3 ^{11 is} provided which is essentially over the entire width and height of the rear side of the cooling chamber and serves as the interior of a cold chamber 103 and in which the evaporator formed as a coil 101 is arranged at a small distance from the cooling wall designated as a whole as 102 and at a somewhat greater distance from the rear wall designated as 104 and having thermal insulation. This evaporator extends essentially over the entire surface of the cooling wall. The cooling wall here consists of two layers 105 and 106, of which the layer 105 consists of plastic of low thermal conductivity and the thin heat-conductive layer 106 of a metal of high thermal conductivity - here aluminum. The layer 105 is considerably thicker than the layer 106 in order to bring about a large temperature gradient with a low heat capacity of the cooling wall during the cooling phases. The thickness of the heat conducting layer 106 can, for example, advantageously be approximately 0.2-0.4 mm, preferably approximately 0.3 mm. The heat-conducting layer 106 has, among other things, the task of equalizing the temperature of the rear side 120 of the layer 105 and thus improving the temperature uniformity of the cooling surface 121. It also accelerates heat conduction. Furthermore, it forms an airtight protective layer which, if the layer 105 is damaged, for example a crack, prevents the penetration of moist cold room air into the cold chamber 103. The thermal conductive layer 106 is like this

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thin that it does not disadvantageously increase the heat capacity of the Eühlwand. Overall, the cooling wall has a very low heat capacity and thus the cooling system has a very low inertia, through which, in particular, a rapid, automatic defrosting of the clay on the cooling surface frozen precipitate is brought about during each shutdown phase. During the cooling phases, a significant temperature difference between the cooling surface 121 and the evaporator 101, which are here to the rope in the plastic layer 105 and partly in the interior of the Cold chamber 103 forms. The thickness of the layer 105 and the distance of the evaporator tubes from the cooling wall are like this met that the desired temperature difference that for example, depending on the desired "ratios, can be 10 ° to 35 ° O. For example the thickness of the layer 105 about 1.5 mm and the distance of the evaporator tube must be 1 mm from the cooling wall.

In Pig. The variant shown in 2 has the cooling wall 102 * a first plastic layer 107, a second made of flexible material, also airtight Plastic layer 109 and also on all areas that are not opposite to any evaporator tubes of the evaporator 101 ', a thin thermal layer 110 made of sheet aluminum on. The layers 107, 109 and 110 are expediently glued to one another, for example by the fact that the layer 109 is designed as a double-sided adhesive film which can optionally have a fabric insert. the both layers 107 and 109 are formed so that due to their poor thermal conductivity and their thickness the desired temperature difference during the cooling phases between the evaporator tubes lying against the layer 109 of the evaporator 101 'and the cooling surface 130'. The synthetic layer 107 can, for example, expediently be a Thickness of about 1.5-2 mm, the layer 109 a substantial one

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smaller thickness and the layer 110 a thickness of approximately 0.2-0.4 mm. Layer 109 has the particular task of preventing the evaporator from being exposed to moist cold room air if the layer 107 becomes hot. The heat conducting layer 110 has, inter alia, the task of imparting an approximately uniform temperature to the layer 109 adjoining it and of conveying heat directly to the evaporator. For this purpose, this layer is in this embodiment not only with the I ^{1 Iu id located in the cold room 103 1} , but also with the evaporation pipes in direct heat-conducting connection. The evaporator tubes have the tubular body 131 partially encompassing profiled sheets 111 made of thermally conductive material, which are firmly connected to the adjacent layers 110. In this exemplary embodiment, the profiled sheets 111 are integral with the heat-conducting layers 110, so that the parts 110 and 111 form a single profiled sheet-metal plate of approximately the same thickness. In terms of puncture, the profiled sheets 111 form part of the evaporator, while the sheet metal pieces 110 form parts of the cooling wall 102 '. In this preferred exemplary embodiment, the heat removed from the cooling space during the cooling phases is supplied to the evaporator tubes partly by conduction in the layer 110 and partly by convection and conduction in the fluid filling the cold chamber 103 '. This combination results in a particularly low inertia of the cooling system and thus, inter alia, particularly rapid defrosting of any frost that may be on the cooling surface of the cooling wall during the shutdown phases.

In both exemplary embodiments, the cold chambers are with a fluiduro capable of flowing - here air - filled, that cannot generate frozen precipitation in the cold chamber. This means that the cold chambers always remain free of ripening, which means among other things, the defrosting process is improved.

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Claims (8)

c-14 -V- claims 1. Cooling device, preferably a refrigerator or the like with at least one cold room, preferably a normal cold room, the at least one separate cold chamber is assigned, in which there is at least one evaporator a refrigerating machine and a free-flowing fluid that is not frozen in the cold chamber Can generate precipitation, whereby the cold chamber and the cold room have a common, as a partition from- ' have formed cooling wall, whose cooling surface facing the cooling space during the cooling phases of the evaporator is cooled over a significant temperature gradient, according to Main patent. . (Patent application B 95 406 Ia / 17a), characterized in that at least a partial area of the cooling wall (102j102 ^! ) of the cold chamber having the evaporator has at least one thin heat-conducting layer (iÖ6; 110) of a material with good thermal conductivity, preferably an aluminum layer, and that at least one further layer (1O5; 1O7,1O9 ) the cooling wall consists of a substance of low thermal conductivity and low thermal capacity, the layer thickness of which is preferably substantially greater than the thickness of the heat-conducting layer. 2. Cooling device according to claim 1, characterized in that the heat-conducting layer to the interior of the cold chamber (1Ο3; 1Ο3 ·) is adjacent. 3. Cooling device according to claim 2, characterized in that the heat-conducting layer with the evaporator (101 ') in thermally conductive contact. 4. Cooling device according to claim 3, characterized in that - 9 009834/0353 1765 D -Sf- - " 0-14 ', that the thermally conductive layer consists of sub-areas (110) of a profiled sheet (111), the other sub-areas (110) which form the outer wall parts of the evaporator (101 *). 5. Cooling device according to one of the preceding claims, characterized in that the thermally conductive 'layer is extends over the entire Kühlwanä. 6. coolness inr loht ung according to any one of claims 1-4, characterized characterized in that the, thermally conductive layer with With the exception of the evaporation tubes opposite areas of the cooling wall over the rest of the surface of the cooling wall extends. 7. Cooling device according to one of the preceding claims, characterized in that the evaporator tubes of the evaporator (101 ') rest against the cooling wall .. 8. Cooling device according to one of the preceding claims, characterized in that the thickness of the thermally conductive layer is approximately 0.2-0.4, preferably approximately 0.3 mm, amounts to. 009834/03 5 3