EP3172507B1 - Refrigeration appliance comprising a fluid reservoir - Google Patents

Description

The present invention relates to a refrigeration appliance, in particular a domestic refrigeration appliance, with a heat-insulating wall delimiting a cooled storage chamber and a tank embedded in the wall. Such tanks are widely used to supply a cold water dispenser in household refrigerators.

If such a tank is filled with water, its temperature must not fall below 0 ° C, first, because the expansion of the water accompanying expansion damage the tank and / or compress an adjacent to the tank layer of insulating material and thus affect their thermal insulation capacity and second, because when the contents of the tank are frozen, cold water can no longer be tapped off. If the storage chamber with the tank in the wall is designed for operation below 0 ° C, appropriate measures must be taken to ensure that the tank does not freeze.

Out DE 10 2006 052 554 A1 is a refrigeration device with integrated into the rear wall of a dispenser water tank known, in which on one side of the tank air-conveying lines are recessed, which communicate via a passage in the insulating material layer of the wall with the storage chamber. These conduits act as a tank cooling heat exchanger which uses the air of the storage chamber as the heat transfer fluid. The low heat capacity of the air requires a fan to provide sufficient air circulation to cool the tank under normal operating conditions. On the other hand, in order for this air to circulate quietly at low speed, the cross-section of the lines must be large and, due to the tight installation space, the length of the lines is small. The combination of small length and large cross-section means that the air circulates through the heat exchanger even when the fan is not in operation.

The US 4,866,949 discloses a refrigerator having an output on a front door for a refrigerated carbonated liquid such as water or drinks. In the front door, a carbonator is provided, which is cooled by an evaporation unit. The Evaporation unit communicates with a liquefaction unit which is arranged in the freezer compartment.

The US 2009/0260371 A1 discloses a refrigeration device with a first and a second refrigeration cycle equip, the second refrigeration cycle 52 is supplied by a coupler 72 of the first refrigeration cycle 30 with thermal energy.

The US 3,908,394 B discloses a refrigerator with a valve and a piping system for beverage dispensing. The pipe system contains frozen ice. When the valve is opened, the pipe system expands due to the water pressure and the water flowing past the frozen ice 44 is cooled.

The WO 2010/034330 A1 discloses a beverage cooler having a cooling vessel having an inlet and an outlet for conveying drinks to and from the cooling vessel. Through the cooling tank, a cooling pipe is guided to cool the drink in the cooling tank.

The DE 10 2005 014 742 A1 discloses a device for cooling drinks with a phase change material containing cold storage equip. The cold storage can be arranged in a wall or within the interior of the shock cooling device. Through the cold storage a pipe is passed for a liquid to be cooled.
The US 2,709,343 discloses a refrigerator with an attached to the ice tank evaporator, wherein the evaporator cools the refrigerator and the ice tank. A condenser is arranged in the engine room of the refrigerator.

To ensure that this does not lead to freezing of the tank contents at a low target temperature of the storage compartment and low outside temperature, an electric heater is additionally arranged on the tank. Their operation, however, requires additional energy, and since the heat released by the heater ultimately heats the storage chamber, their operation also leads to longer compressor run times. The heater thus significantly affects the energy efficiency of the refrigerator.

Object of the present invention is to provide a refrigeration device with a recessed in a heat-insulating wall tank, in which a supercooling of the tank can be avoided without the use of heating.

The object is achieved by providing in a refrigeration appliance, in particular a household refrigeration appliance, with a heat-insulating wall defining a cooled storage chamber, a tank embedded in the wall and a conduit for a heat transfer fluid, part of which is arranged in thermal contact with the tank first heat exchanger forms, a shut-off is provided which is switchable between a circulation of the heat transfer fluid in the line permitting position and a circulation blocking position.

According to the invention, a second heat exchanger is arranged on an inner side of the heat-insulating wall. In particular, it may, like a coldwall evaporator, be arranged between an inner skin and an insulation material layer of the heat-insulating wall.

Preferably, the heat transfer fluid is a liquid, since it is able to transfer more heat energy than a gas with a small line cross-section and low flow velocity. The heat exchanger therefore occupies significantly less space in a refrigerator than a conventional, working with air as a heat transfer heat exchanger, so that the usable volume of the refrigerator can be increased.

The first heat exchanger is preferably arranged on one of the bearing chamber side facing the tank. Thus, it is shielded from ambient heat by the tank itself by incoming ambient heat, and unnecessary heat input into the heat transfer fluid is avoided.

If the heat transfer fluid is a liquid, it can not be sucked directly from the storage chamber and released into it. Preferably, therefore, the conduit is a closed circuit, of which a second part forms a second heat exchanger arranged in thermal contact with the storage chamber.

An adhesion of the second heat exchanger to the inner skin favors the heat exchange with the storage chamber.

If the second heat exchanger is arranged above the first heat exchanger, convection, which is excited by cooling of the heat transfer fluid in the second heat exchanger, promote the heat transport in the circuit, without this additional energy must be expended.

In order to control the circulation of the heat transfer fluid, a pump may be arranged in the closed circuit.

Such a pump may suitably also serve as a shut-off member for preventing the circulation. Particularly suitable for this purpose are pumps in which the driven elements completely fill the free cross-section of the circle, such as gear or rotary vane pumps, which blocked in the case of the stoppage of the movable elements of the cross-section of the circle and thereby the circulation is blocked.

Alternatively, a controllable valve can serve as a shut-off.

A control signal for such a valve and / or for the pump can be provided in particular by a thermostat control.

If the storage compartment can be cooled to a setpoint temperature below the freezing point of the heat carrier fluid, the shut-off member can also be formed by at least a portion of the second heat exchanger, which can be closed by freezing heat transfer fluid. By blocking the heat transfer fluid at too low a temperature, this closable section can also prevent excessive cooling of the tank, which could lead to the freezing of its contents.

Yet another alternative to consequence, the expansion of the water during freezing can be used by the shut-off member comprises a water-filled expandable chamber whose volume expansion during freezing at least narrows the cross-section of the conduit.

Fig. 1

einen schematischen Schnitt durch ein erfindungsgemäßes Kältegerät;

Fig. 2

den Verlauf einer Wärmeträgerleitung an der Innenseite der Tür des Kältegeräts gemäß einer ersten Ausgestaltung der Erfindung;

Fig. 3

den Verlauf der Wärmeträgerleitung gemäß einer zweiten Ausgestaltung in einer zu Fig. 2 analogen Darstellung;

Fig. 4

ein vergrößertes Detail der wärmedämmenden Wand des Kältegeräts im Schnitt gemäß einer dritten Ausgestaltung; und

Fig. 5

einen zu Fig. 4 analogen Schnitt gemäß einer vierten Ausgestaltung.

Further features and advantages of the invention will become apparent from the following description of embodiments with reference to the accompanying figures. Show it:

Fig. 1

a schematic section through an inventive refrigerator;

Fig. 2

the course of a heat carrier line on the inside of the door of the refrigerator according to a first embodiment of the invention;

Fig. 3

the course of the heat carrier line according to a second embodiment in a too Fig. 2 analog representation;

Fig. 4

an enlarged detail of the heat-insulating wall of the refrigerator in section according to a third embodiment; and

Fig. 5

one too Fig. 4 analog section according to a fourth embodiment.

This in Fig. 1 shown in a schematic section refrigeration device has a heat-insulating body 1 and a door 2, which define an interior. The interior is divided into a storage chamber 3, here a freezer compartment, and an evaporator chamber 4, in which an evaporator and a fan for circulating air between the evaporator chamber 4 and the storage chamber 3 are housed.

An icemaker 5 is arranged immediately below the evaporator chamber 4 in the storage chamber 3 in order to be able to be charged directly with cold air from the evaporator chamber 4. Under the icemaker 5 a collecting container 6 is mounted, which catches ice pieces 5 produced by the icemaker. A screw conveyor 7 at the bottom of the collecting container 6 serves to convey ice pieces to an outlet 8 at a door near the end of the collecting container. 6

In a central area of the door 2, there is formed a niche 12 in which a user can place a container to discharge ice from the sump 6 without opening the door 2. An upper wall of the niche 12 lies below the outlet 8 of the collecting container 6. Through this wall extends a tubular or funnel-shaped passage, also referred to as an ice chute 9. At the lower end of the ice chute 9, a movable flap 10 is arranged, which blocks the ice slide 9 airtight in the closed position, so that no hot air from the niche 12 can pass through the ice chute 9 in the storage chamber 3.

On an outer side of the flap 10, a water outlet 11 is arranged, via which a container placed in the niche 12 can also be filled with cold water from a tank 13. The tank 13 is in a wall of the niche 12, here a rear wall, taken in and separated from both the niche 12 and the storage chamber 3 by a thermal barrier coating 14 so that the tank 13 in stationary operation, a temperature is set between the Temperature of the storage chamber 3 and the environment is located.

The tank 13 is connected via a through the door 2 and walls of the body 1 extending line 15 to a domestic water, not shown. When water is tapped from the tank 13 into a container of the niche 12, a solenoid valve 16 is opened in the line, so that cold water is displaced from the tank 13 by flowing from the domestic water line forth, relatively warm water. If this water could only transfer its heat to the storage chamber 3 via the thermal barrier coating 14, it would take a very long time before cold water can be tapped again. In order to avoid this, it is necessary to be able to intensify the heat exchange between the tank 13 and the storage chamber 3. If necessary, it must also be possible to stop this heat flow again to prevent freezing of the water in the tank 13.

For this purpose, in the door 2, two heat exchangers 17, 18 in a heat transfer circuit 22 connected to each other, in which a heat transfer fluid circulated. One of them, also referred to here as a cold heat exchanger 17, is arranged on an inner side of the door 2 in close thermal contact with the storage chamber 3. Preferably, it is hidden behind a deep-drawn in a customary manner of plastic inner skin of the door 2. In order to enable a rapid heat exchange, the cold heat exchanger 17 may have a line with a flattened, lying surface on the inner skin cross-section; Alternatively or additionally, an adhesive layer in a limited by the outer skin and a rounding of the pipeline gusset the area on which an intense heat exchange is possible to increase. The freezing point of the heat transfer fluid is below the lowest setpoint temperature which can be set for the storage chamber 3, so that freezing of the heat transfer fluid in the cold heat exchanger 17 is precluded. The heat transfer fluid may be, for example, a common antifreeze solution for use in automobile radiators.

The other, warm heat exchanger 18 is in contact with the tank 13. The warm heat exchanger 18 is located here on a side facing the storage chamber 3 of the tank 13 to be isolated from the environment by the tank 13 itself and thus to avoid unnecessary heat absorption from the environment.

Fig. 2 shows an interior view of the door 2 according to a first embodiment of the invention. The heat exchangers 17, 18 and connecting lines 19, 20 are in Fig. 2 shown in dashed lines, since they are not visible in reality. Rather, the cold heat exchanger 17 is enclosed above the niche 12 between the door inner skin covering the entire inner door surface and the thermal barrier coating 14, and between the warm heat exchanger 18 and the inner skin is in addition a part of the thermal barrier coating 14th

The heat exchangers 17, 18 and lines 19, 20 may be integrally formed of a pipe or hose made of metal or plastic, which in the case of Fig. 2 extends in vertically oriented meanders. The two ends of the tube or hose are connected to the inlet and outlet of a pump 21 to form a closed circuit. The pump 21 is shown here in the line 19, but could be placed anywhere in the heat transfer circuit 22, also within one of the heat exchanger 17, 18.

The pump 21 is connected to a temperature sensor 23, which is arranged on an upper side of the tank 13. The temperature sensor 23 sets the pump 21 in motion when a high detected temperature or a rise in temperature suggests that fresh water has flowed from the house water line, and switches off the pump 21 as soon as a limit temperature of some degrees above 0 ° C is exceeded ,

The design of the pump 21 is chosen so that it blocks the circulation of heat transfer fluid through the heat exchangers 17, 18 in the off state. Thus, for example, a gear pump as a pump 21 into consideration.

If e.g. a centrifugal pump or a pump is generally used, which does not block the heat transfer circuit 22 at standstill, a valve should be provided in the heat transfer circuit 22, which serves as a shut-off when the pump is switched off. Even so, a cooling of the tank 13 via the heat transfer medium 22 can be reliably prevented if the temperature of the water in the tank 13 is close to 0 ° C.

In the embodiment of Fig. 3 the meanders of the heat exchangers 17, 18 are oriented horizontally, the conduit 19 connects directly to the upper ends of the heat exchangers 17, 18, and the conduit 20 connects directly to the lower ends thereof. This asymmetry favors a purely convection-driven circulation of the heat transfer fluid in the circuit 22. A via a temperature sensor on the tank 13 controlled valve 24 acts as a shut-off, which prevents the circulation of the heat transfer fluid at low temperature of the tank 13. Again, the valve 24 is shown in the conduit 19, but could be positioned at any other location in the circuit 22.

Fig. 4 shows a section of the door 2, which separates the tank 13 from the storage chamber 3, according to a third embodiment of the invention. The freezing point of the heat transfer fluid is in this embodiment below 0 ° C, but above the temperature of the storage chamber 3, and accordingly the cold heat exchanger 17 is here separated from the storage chamber 3 by a thin layer of thermal insulation material, which prevents freezing of the heat transfer fluid in the heat exchanger 17 , In the thermal barrier coating 14, here at the top of the niche 12, a heat-conducting body 25 is embedded, with one end to the inner skin 26 of the door, with the other end to the top of the tank 13 rests and has a passage through which the heat transfer circuit 22, here again the line 19, runs. The cross section of the heat conducting body 25 is small in relation to the surface of the tank 13; accordingly, its influence on the temperature of the tank 13 is negligible. The passage forms a bottleneck 27 of the circuit 22. The surfaces of the heat-conducting body 25 delimiting the bottleneck 27 assume a temperature between that of the storage chamber 3 and that of the tank 13. The freezing point of the circulating in the heat transfer medium 22 heat transfer fluid is chosen so that the adjacent to the bottleneck 27 surface of the heat conducting body 25 falls below this temperature when the temperature of the tank 13 is just above 0 ° C. The layer 28 of solidified heat transfer fluid, which forms in this case in the bottleneck 27, constricts the bottleneck 27 in addition. This reduces the flow rate of the heat transfer fluid, which further promotes the growth of the layer 28. As soon as it closes off the bottleneck 27, here too the heat transfer between the heat exchangers 17, 18 stops, without the need for a temperature sensor. When water is tapped and hot water flows from the domestic water pipe, this collects primarily in the upper part of the tank 13 and heats the heat-conducting body 25, so that the layer 28 melts and the heat transport gets going again. A switchover between an open and a locked state of the bottleneck 27 takes place here directly controlled by the temperatures of the storage chamber 3 and the tank 13, without a detour via electronic control circuits.

Fig. 5 shows you one Fig. 4 analog section according to another embodiment of the invention. Again, a heat-conducting body 25 is arranged between the inner skin 26 and the tank 13. The heat conducting body 25 contains here on its side facing the bearing chamber 3 side a water-filled and closed with a movable piston 30 chamber 29. Before the tank 13 cools to 0 ° C, the contents of the chamber 29 freezes and drives the piston 30 into the bottleneck 27 inside , so that the circulation of the heat transfer fluid preferably comes to a complete stop, but at least severely limited, to prevent freezing of the tank 13.

REFERENCE NUMBERS

1

corpus

2

door

3

storage chamber

4

evaporator chamber

5

Ice makers

6

Clippings

7

Auger

8th

outlet

9

ice chute

10

flap

11

water outlet

12

niche

13

tank

14

thermal barrier

15

management

16

magnetic valve

17

heat exchangers

18

heat exchangers

19

management

20

management

21

pump

22

Heat transfer circuit

23

temperature sensor

24

Valve

25

thermal conductors

26

inner skin

27

bottleneck

28

layer

29

chamber

30

piston

Claims (9)

1. Refrigeration appliance, in particular a household refrigeration appliance, with a heat-insulating wall which delimits a cooled storage chamber (3), a reservoir (13) let into the wall and a conduit for a heat transfer medium fluid, part of which forms a first heat exchanger (18) arranged in thermal contact with the reservoir (13), and a shut-off element (21, 24, 27), which can be switched between a position that allows circulation of the heat transfer medium fluid in the conduit and a position that blocks circulation, and the conduit is a closed heat transfer medium circuit (22), a second part of which forms a second heat exchanger (17) arranged in thermal contact with the storage chamber (3), and the second heat exchanger (17) is arranged on an inner face of the heat-insulating wall, characterised in that the second heat exchanger (17) is arranged between an inner skin (26) and an insulating material layer (14) of the heat-insulating wall.
2. Refrigeration appliance according to claim 1, characterised in that the heat transfer medium fluid is a liquid.
3. Refrigeration appliance according to claim 1 or 2, characterised in that the first heat exchanger (18) is arranged on a face of the reservoir (13) facing the storage chamber (3).
4. Refrigeration appliance according to claim 1, characterised in that the second heat exchanger (17) is arranged above the first heat exchanger (18).
5. Refrigeration appliance according to one of claims 1 or 4, characterised in that a pump (21) is arranged in the closed heat transfer medium circuit (22).
6. Refrigeration appliance according to claim 5, characterised in that the pump (21) forms the shut-off unit.
7. Refrigeration appliance according to one of claims 1 to 6, characterised in that a controllable valve (24) forms the shut-off unit.
8. Refrigeration appliance according to one of claims 1, 4, 5 or 6, characterised in that the storage compartment (3) can be cooled to a setpoint temperature below the freezing point of the heat transfer medium fluid and the shut-off unit is formed by at least one segment (27) of the heat transfer medium circuit (22), which can be closed off by freezing heat transfer medium fluid.
9. Refrigeration appliance according to one of claims 1, 4 or 5, characterised in that the shut-off unit (27) comprises a water-filled expandable chamber (29).

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