EP2126486B1 - Refrigerator - Google Patents

Description

The invention relates to a refrigerator according to the preamble of claim 1.

It is known to arrange ice makers in the cold room of refrigerators. Here, on the one hand ice makers are used, which are filled with water and cooled from the outside, the water freezes from the outside to the inside and finally results in an ice cube. Further, there are so-called Klareisbereiter, in which a plurality of cold fingers immersed in a container filled with water. An ice layer grows on the cold fingers that dip into the water, which, once it has reached a ready-to-use size, is released from the cold fingers. Such a Klareisbereiter is in the DE 103 36 834 A1 described. This type of icemaker finally exists in a variety of embodiments. Such ice makers are generally installed in the refrigerated compartment of a refrigerator-freezer.

The refrigerator of the refrigerator usually consists of a cooling circuit for a refrigerant with a compressor, a condenser and an evaporator, which extracts the heat from the interior to be cooled and transfers to the refrigerant. In general, the evaporator is designed as a wire tube evaporator and arranged in the freezer. The evaporator acts as a heat exchanger between the air in the interior and the refrigerant. In wire-tube evaporators, the refrigerant-carrying evaporator tube is bent into parallel loops. The pipe loops are firmly connected with wire rods - usually by spot welding - and thus stabilized. The wire rods run at parallel intervals at right angles to the straight pipe sections of the pipe loops at their top and bottom. The purpose of connecting the pipe loops carrying the refrigerant to the wire rods is to prevent sagging of the pipe loops on the one hand and to achieve a higher cooling capacity by increasing the surface area, on the other hand.

If an icemaker is provided in the refrigeration device, this can be connected, for example, to the Be connected cooling circuit of the refrigerator. Another possibility is to equip the ice maker with its own refrigerant circuit and to couple this thermally to the evaporator of the refrigerator.

In the case of clear coaters, it has been found that clear, transparent ice can only be produced if the cold fingers have a temperature that is a few degrees below zero. It is essential that the temperature is kept very evenly. However, this is not possible without additional regulation, since the cooling capacity of the refrigeration device is determined by other conditions, such. B. the amount of stored refrigerated and frozen goods, directed.

The publication EP 0 453 809 A2 shows an apparatus for producing Klareisstücken, according to the preamble of claim 1.

The publication FR 2 880 676 A1 shows an apparatus for producing ice, wherein two independently operable coolant circuits are provided.

The publication US 2005/109056 A1 shows a refrigerator comprising two cooling chambers, each with an arranged in the refrigerator evaporator. The two evaporators are part of a refrigerant circuit comprising a compressor and a condenser.

The invention has the object of providing a refrigeration device in such a way that the temperature required on the cooling fingers of a Klareisbereiters, without being affected by the temperature control of the refrigerator, can be maintained very constant. The necessary components must be inexpensive and must not greatly increase the manufacturing cost of the refrigerator.

The object is achieved according to the invention by a refrigerator with the features of claim 1. By the presence of a bypass line, via the refrigerant the refrigerant can be passed over, the possibility exists, refrigerant from the cold fingers of Klareisbereiters, which has already absorbed heat, so to mix with the coming of the refrigerant refrigerant that sets the prescribed temperature constant in the cooling fingers of Klareisbereiters.

In the simplest case, a refrigerant is used whose viscosity changes with the temperature in the relevant temperature range. In the return line to the chiller between bypass line and chiller a correspondingly sized throttle, in the bypass line itself a pressure relief valve installed. Now, if the refrigerant flowing back from the cooling fingers of low temperature and therefore viscous, only a small part flows through the throttle to the chiller. Of the larger part of the refrigerant is forced into the bypass line, as the pressure applied opens the pressure relief valve. At the end of the bypass line, the volume flow originating directly from the cooling fingers is mixed by the bypass line with the small volume flow from the cold generator and returned to the cooling fingers. On the other hand, if the temperature of the refrigerant flowing back from the cooling fingers is relatively high, a larger amount of this low-viscosity refrigerant is forced through the throttle to the cold generator, while only a small volume flow flows via the bypass line. If the temperature were to increase even further for an undetermined reason, so much refrigerant is forced through the throttle that the pressure is insufficient to open the pressure relief valve. In this case, the entire refrigerant is supplied to the cold generator, so that sets very quickly at the cold fingers again a low temperature.

In a preferred embodiment, however, a controllable device is provided with which the flow rates of refrigerant are controlled by the refrigerator and the bypass line. Furthermore, a temperature sensor is provided, which supplies the control condition for the control device.

In one embodiment of the invention, the controllable device is designed as a 3-way valve. Such 3-way valves are also known as "mixers" or "mixing valve". The 3-way valve may, for example, be provided where the bypass line is guided together with a line coming from the cold generator. The two refrigerant streams can then be mixed together so that sets exactly the desired temperature on the temperature sensor.

In another embodiment, a 2-way valve is provided. This simple valve can be provided in the line to, or the line from the cold generator, but also directly in the bypass line. Advantageously, however, it is in the line that comes from the chiller at one point before this line is merged with the bypass line. In this way, only the volume flow of the Refrigerant regulated coming cold refrigerant. The volume flow through the bypass line adjusts accordingly.

In a further embodiment, a second 2-way valve is provided in the bypass line. As a result, a direct control of both flow rates, ie the refrigerant flowing at a higher temperature through the bypass line and the refrigerant, which comes with a lower temperature from the chiller, possible.

The 2-way valves can be designed in their simplest form so that only an open or closed position is possible. In order to be able to regulate the volume flow as accurately as possible, the valves can be clocked, for example, with a variable frequency. This means that either different fixed times are assigned to a fixed closed time, or different closed times to a fixed open time.

Particularly preferably, the cold generator is formed in the cooling circuit of Klareisbereiters as a heat exchanger. This heat exchanger is thermally coupled to the evaporator of the refrigerator. Therefore, neither a refrigerant circuit with its own compressor, evaporator and condenser has to be provided for the overhead freezer, nor must the clearing machine be connected directly to the refrigerant circuit of the refrigeration device. In order to move the refrigerant through the heat exchanger and the cold fingers of the clarifier, a circulation pump is integrated into the cooling circuit.

As a refrigerant, a mixture of glycol and water has been found to be advantageous. This mixture can be adjusted so that it remains liquid in the required temperature range and is still inexpensive to produce.

Advantageously, a heating device is provided in the cooling circuit of the clear ice maker. By activating this heater, the refrigerant can be heated so far that the generated clear ice dissolves from the cooling fingers and in a Collecting tray can be collected. As a result, a separate heating device can be saved on each individual cold finger.

Further details and advantages of the invention will become apparent from the dependent claims in connection with the description of exemplary embodiments, which are explained in detail with reference to the drawing.

Fig. 1

ein erfindungsgemäßes Kältegerät mit Gefrierfach und Eisbereiter,

Fig. 2

eine Detaildarstellung eines Drahtrohrverdampfers mit angekoppeltem Wärmetauscher,

Fig. 3

ein erstes Ausführungsbeispiel des Kältekreislaufs eines Klareisbereiters,

Fig. 4

ein zweites Ausführungsbeispiel und

Fig. 5

ein weiteres Ausführungsbeispiel.

It shows:

Fig. 1

an inventive refrigerator with freezer and icemaker,

Fig. 2

a detailed representation of a wire tube evaporator with coupled heat exchanger,

Fig. 3

A first embodiment of the refrigeration cycle of a Klareisbereiters,

Fig. 4

a second embodiment and

Fig. 5

another embodiment.

FIG. 1 shows a refrigerator 1 with the door open and an interior 11. The interior 11 is divided into a refrigerator 2 and a freezer compartment 3. For reasons of clarity, no closure flap is shown on the freezer compartment 3. In the refrigerator 2 is a Klareisbereiter 4. In this Klareisbereiter 4 is in a process not further explained here by means of several cold fingers Klareis produced, which is stored in a drip tray 10. The drip tray 10 is located below the clear ice maker 4. The cold needed to produce the clear ice is mixed with a heat exchanger 5 (see also Fig. 2 ), which is firmly connected to the cold fingers.

The horizontally arranged wire tube evaporator 6 located in the freezer compartment 3 consists of an evaporator tube 7 bent into parallel loops. The evaporator tube 7 of the wire tube evaporator 6 is firmly connected on the top and bottom with wire rods 8, which run parallel to the end side and to one another have the same distance. The attachment of the wire rods 8 causes on the one hand a surface enlargement, through which the heat from the freezer compartment 3 can be better absorbed, and on the other hand prevents sagging of the evaporator tube 7 of the wire tube evaporator 6. The sake of clarity are in FIG. 2 only the wire rods 8 of the wire tube evaporator 6 are shown, which are located on the front side and on the opposite side.

The heat exchanger 5 consists of a heat exchanger tube 9. The heat exchanger tube 9 of the heat exchanger 5 is also performed in the region of the wire tube evaporator 6 parallel to the evaporator tube 7 in loops in the same plane. Here, the heat exchanger tube 9 of the heat exchanger 5 is just between the wire rods 8 as the evaporator tube 7 of the wire tube evaporator. 6

In order to couple enough heat from the heat exchanger 5 in the wire tube evaporator 6, a good thermal contact between these two components is necessary. For this purpose, the heat exchanger tube 9 of the heat exchanger 5 is fixedly connected to the evaporator tube 7 and the lower and upper wire rods 8 of the wire tube evaporator 6. The heat exchanger tube 9 of the heat exchanger 5 has the same outer diameter and consists of the same material as the evaporator tube 7 of the wire tube evaporator. 6

As well thermally conductive compounds spot welding, soldering or gluing are possible. Also, a coating, in particular a powder coating, which is applied to the finished assembled construct of heat exchanger 5 and wire tube evaporator 6, sufficiently thermally conductive.

Fig. 3 shows a first embodiment of the cooling circuit of the Klareisbereiters 4. The cooling circuit is filled in particular with a water-glycol mixture, which is inexpensive to produce and is liquid in the relevant temperature range. The refrigerant is in the heat exchanger 5 is cooled by the wire tube evaporator 6. With the help of the circulation pump 17, the refrigerant is circulated. In the circuit in front of the Klareisbereiter 4 is the temperature sensor 13, is controlled by means of which, whether the refrigerant has the temperature required for the production of clear ice. The heater 14 is needed to dislodge the finished clear ice from the cold fingers of the clear ice maker so that it can be collected in the drip tray 10. The bypass line 18 is turned on in the cooling circuit, that refrigerant can be passed to the heat exchanger 5. About the return line 19 is refrigerant, which has already passed through the Klareisbereiter 4, fed back to the heat exchanger 5. The cold valve 12 is switched between the heat exchanger 5 and the bypass line 18 in the cooling circuit. In a very simple version, the cold valve 12 is designed as a shut-off valve, which can be controlled only in a closed or an open position.

As soon as the circulation pump 17 is put into operation, a partial flow of the refrigerant is conducted via the reflux line 19 and another partial flow via the bypass line 18. As a result, a cold partial flow from the heat exchanger 5 and a warmer partial flow from the bypass line 18 mix in front of the circulation pump 17. The flow cross section of the bypass line 18 is set so that under normal conditions by the mixture of the cold and the warmer partial flow at the temperature sensor 13, a temperature of the refrigerant results, which is below the ideal for the Klareisbereiter 4 temperature. The cold valve 12 is provided to affect the temperature of the refrigerant in the Klareisbereiter 4 can. If a temperature is detected at the temperature sensor 13 which is too low to be able to produce really clear ice, the partial flow via the reflux line 19 and the heat exchanger 5 must be reduced and the partial flow through the bypass line 18 increased. For this purpose, the cold-valve 12 is clocked, that is closed at a certain frequency and opened again. The longer the closing times of the cold valve 12, the larger the partial flow through the bypass line 18. When the measured temperature of the refrigerant is too low, consequently, the closing times of the Cold valve 12 extended and at a high measured temperature of the refrigerant, the closing times of the cold valve 12 can be reduced.

However, the cold valve 12 may also be designed as a controllable valve. Such a valve need not be clocked because the opening cross-section of the valve is adjustable. With each position of the valve, therefore, a certain mixing ratio of the partial flows from the bypass line 18 and the heat exchanger 5 can be achieved.

If a corresponding ice thickness is reached on the cooling fingers of the clear ice maker 4, the heating device 14 is switched on. At the same time, the cold valve 12 is completely closed. The refrigerant is heated to a temperature just above 0 ° C and passed completely through the bypass line 18. As soon as the temperature in the clear ice maker 4 is above the 0 ° C limit, the ice, which is in direct contact with the cold fingers, melts and the finished clear ice falls into the drip tray 10.

In the in Fig. 4 shown embodiment, the bypass valve 15 is additionally turned on in the bypass line 18. Regardless of whether the valves 12 and 15 are clocked or provided with a continuously variable flow cross-section, in this embodiment, the temperature of the refrigerant can be controlled faster and more direct, so that the desired temperature of the refrigerant can be maintained in the Klareisbereiter 4 with lower fluctuations.

An even more direct temperature control is possible with the embodiment, which in Fig. 5 is shown. Here, a mixing valve 16 is used instead of the two valves 12 and 15. This mixing valve 16 is located where the partial flow from the heat exchanger 5 is combined with the partial flow from the bypass line 18. With the mixing valve 16, these partial flows can be controlled directly. In this way, the temperature of the refrigerant in the Klareisbereiter 4 is very accurate and adjustable without fluctuation.

LIST OF REFERENCE NUMBERS

1

The refrigerator

2

refrigerator

3

freezer

4

Klareisbereiter

5

heat exchangers

6

Wire tube evaporator

7

evaporator tube

8th

wire rod

9

heat exchanger tube

10

drip tray

11

inner space

12

Cold valve

13

temperature sensor

14

heater

15

bypass valve

16

mixing valve

17

circulating pump

18

bypass line

19

Return line

Claims (10)

1. Refrigerator (1) with an interior (11) for storing chilled and/or frozen items and, disposed in the interior (11), an ice maker (4) which is cooled via a refrigerant circuit, said refrigerant circuit having a cold generator (5) for cooling the refrigerant, characterised in that the refrigerant circuit has a bypass line (18) via which refrigerant can bypass the cold generator (5).
2. Refrigerator according to claim 1, characterised in that there is provided both a controllable device (12, 15, 16) with which the ratio of the amount of refrigerant flowing through the cold generator (5) and the bypass line (18) can be controlled, and a temperature sensor (13).
3. Refrigerator according to claim 2, characterised in that the controllable device is designed as a three-way valve (16).
4. Refrigerator according to claim 2, characterised in that the controllable device is provided as a two-way valve (12, 15).
5. Refrigerator according to claim 4, characterised in that the two-way valve (12) is provided in the direction of flow between the cold generator (5) and the bypass line (18).
6. Refrigerator according to claim 5, characterised in that another two-way valve (15) is provided in the bypass line (18).
7. Refrigerator according to claim 4, characterised in that the two-way valve (12, 15) is designed as a shutoff valve.
8. Refrigerator according to claim 1, characterised in that the cold generator (5) is designed as a heat exchanger which is thermally coupled to an evaporator (6) of the refrigerator (1) and that a circulating pump (17) is provided in the refrigerant circuit.
9. Refrigerator according to claim 8, characterised in that the refrigerant is a mixture of glycol and water.
10. Refrigerator according to claim 1, characterised in that a heating facility (14) is provided in the refrigerant circuit.

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