EP3371528B1 - Refrigeration device having a flexible compartment - Google Patents

Description

The present invention relates to a refrigeration appliance, in particular a household refrigeration appliance, with a compartment which can be used at greatly differing setpoint temperatures, typically as required by a user as a refrigerated compartment or as a freezer compartment, also referred to as a flexible compartment or flex compartment.

When a user wants to switch such a flex compartment from freeze to normal refrigeration mode, it takes a long time for the new setpoint temperature to be reached solely by heat input from the environment. As long as the new target temperature is not reached, it is risky to use the flex compartment, because the loaded refrigerated goods could be damaged if the temperature is too low.

In WO 2009/061076 A2 Therefore, it has been proposed to use a defrost heater to heat the flex tray faster after raising the set temperature.

The energy efficiency of this method is especially questionable if a single evaporator other than the flex compartment must cool other subjects, since if one of the other subjects refrigeration needs, the heating of the Flexfachs interrupted and cooled down the evaporator chamber at least to the desired temperature of the other compartment and then has to be heated again. It is therefore desirable to be able to completely carry out the heating of the flex compartment between two cooling operating phases.

The object of the present invention is to further accelerate the heating of the flex compartment and to make it more energy efficient.

The object is achieved on the one hand by a refrigerator, in particular domestic refrigerator, with a flexible compartment operable at different temperatures, one housed in a separate evaporator chamber evaporator, a steamer associated with the evaporator and a fan for driving an air flow between the evaporator chamber and the Compartment in which a control unit is arranged to operate simultaneously in a heating operation phase after raising a set temperature of the flexible compartment for heating the flexible compartment fan and defrost heater. Thus, the temperature gradient between the evaporator chamber and flexible compartment can be kept small, and heat flows from the evaporator chamber into other compartments of the refrigerator, in which heating is undesirable, can be kept low.

The controller is preferably further configured to control a defrost operation prior to simultaneous operation of the fan and defrost heater. Thus, transport of water vapor from the evaporator into the flexible compartment and condensation of the steam in the flexible compartment can be largely prevented.

When defrosting is complete and the control unit does so e.g. detected by a measured value of a temperature sensor arranged on the evaporator, the fan can be switched on without switching off the defrost heater.

In order to avoid overshooting the temperature in the flexible compartment above the increased setpoint, in a heating-up phase, switch-on phases in which the fan and the defrosting heater are in operation can alternate with switch-off phases in which the fan and defrosting heater are out of operation.

Nevertheless, in order to achieve the new target temperature quickly, it is expedient that a switch-on phase at the beginning of the heating-up phase is longer than a switch-on phase towards the end of the heating-up phase.

The change of the setpoint temperature can be made manually on a controller of the control unit; however, the control unit may also be arranged to increase the set temperature at a predetermined time to bring the contents of the flexible compartment to a consumption or processing temperature at a given time.

• a) Heraufsetzen einer Solltemperatur des Fachs, und
• d) gleichzeitiges Betreiben des Lüfters und der Abtauheizung, um das Fach auf die Solltemperatur zu erwärmen.

The object is further achieved by a method of operating a refrigeration device with a flexible compartment which can be operated at different temperatures, an evaporator accommodated in an evaporator chamber separate from the compartment, one of the evaporators Evaporator associated defrost heater and a fan for driving an air flow between the evaporator chamber and the tray, with the steps:

• a) increase a target temperature of the compartment, and
• d) operating the fan and defrost heater simultaneously to heat the shelf to the set temperature.

Between steps a) and b), in a step c), the defrost heater can be operated without the fan in order to defrost the evaporator.

Before step d), and preferably also before step c), precooling of other compartments of the refrigeration device may take place in order to maximize the time until the occurrence of cooling demand in these compartments.

Fig. 1

einen schematischen Teilschnitt durch ein erfindungsgemäßes Kältegerät; und

Fig. 2

ein Flussdiagramm eines Betriebsverfahrens des Kältegeräts.

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 partial section through an inventive refrigerator; and

Fig. 2

a flowchart of an operating method of the refrigerator.

Fig. 1 shows a schematic section through the lower part of a household refrigerator. A body 1 and doors 2, 3, 4 limit several storage compartments, here a freezer compartment 5 and a flexible compartment 6, and an evaporator chamber 7. The evaporator chamber 7 is here edgewise arranged between the storage compartments 5, 6 and a rear wall 8 of the body 1; an arrangement on a horizontal partition between two storage compartments would also be considered.

A horizontal partition wall 9 between the flexible compartment 6 and a normal refrigeration compartment 10 only partially shown may extend from the doors 3, 4 continuously to the rear wall 8; in which case a separate evaporator can be provided for the normal cooling compartment 10. Alternatively, however, the evaporator chamber 7 and an evaporator 11 housed therein may also be provided to cool all three compartments 5, 6, 10, in which case a vertical dividing wall 12 enclosing the evaporator chamber 7 of the subjects 5, 6 separates, can extend up to the level of the normal refrigeration compartment 10 and the horizontal partition wall 9 expands to the rear only to the vertical partition wall 12.

Flaps 13, 14 in the vertical partition wall 12 between the evaporator chamber 7 and the adjacent to the partition wall 12 storage compartments 5, 6 and possibly 10 control the distribution of cold air from the evaporator chamber 7 on the storage compartments.

The evaporator chamber 7 is subdivided by a wall 15 into an area in which the evaporator 11 and a defrost heater 16 are accommodated, and a distributor area 17, to which the flaps 13, 14 are connected. A fan 18 is mounted on a passage of the wall 15 to suck air through channels, not shown, in the walls of the body 1 from the storage compartments into the evaporator chamber 7 and through the evaporator 11 and over the manifold portion 17 and the flaps 13, 14 in FIG to pump back the storage compartments.

An electronic control unit 19 is connected to temperature sensors 20, 21, 22, 23 in the storage compartments 5, 6, 10 and the evaporator 7 and to a compressor 24, the fan 18 and the defrost heater 16, to the latter on the basis of the temperatures measured by the sensors be controlled so that the temperatures of the storage compartments 5, 6, 10 each remain within a tolerance interval by a predetermined user by the desired temperature. One in the Fig. 1 not shown user interface of the control unit 19, at which a user can set the target temperatures of the fan is provided at a readily accessible location on the front of the device, this user interface may in particular comprise a display element indicating an excessive deviation between the current temperature and target temperature of a compartment and as a result, is turned on by the control unit 19 in response to a sufficiently large change in the target temperature and is turned off again when the shelf temperature is equalized to the target temperature.

The flexible compartment 6 is characterized by the fact that its target temperature T _{soll is} adjustable to a particularly great extent, between the temperature Tf of the freezer compartment 5 and the normal refrigeration compartment 10 or even beyond the latter.

If wants to use as a freezer compartment 6, the user otherwise the shed 6 by operation of the flexible compartment and for T _set up sets, the control unit 19 the following with reference to the flow chart of Fig. 2 perform the described method.

If an increase of T _soll was detected by a user or made by the control unit 19 on the basis of a time programming itself in step S1, it is first checked in step S2 whether the difference ΔT between the old and the new target temperature T _{soll is} large enough, to justify active heating of the flexible compartment 6, or if it is only a minor correction. Only in the former case, the method goes to step S3 or, in a simplified variant of the method, to step S6, and the display element of the user interface is turned on.

In step S3, it is checked whether the compressor 24 is in operation because of existing refrigeration needs in one of the storage compartments, the same evaporator 11 as the flexible compartment 6, ie at least the freezer compartment 5, possibly also the normal refrigeration compartment 10. If so, then the process remains at this step until the off-threshold temperature of that compartment is reached.

In step S4, the current temperature Tf of the freezing compartment 5 is compared with the switch-off threshold temperature Tf _off , in which the control unit 19 terminates the cooling of the freezer compartment 5 during normal operation. If the current temperature is higher by a predetermined minimum difference .DELTA., Then it makes sense first to turn on the compressor 24 (S5) and to cool the freezer compartment 5 by the period of time thereafter for a heating of the flexible compartment 6 which is undisturbed by the refrigeration requirement of other compartments is available to make as long as possible. Of course, such preventive cooling also take place for the normal cooling compartment 10, if the evaporator 11 is used to cool it.

If in step S4, no need for preventive cooling has been determined or the relevant storage compartment 5 or 10 has been cooled down to reaching its switch-off temperature limit, in step S5 the compressor 24 is turned off and in step S6 the defrost heater 16 is turned on Defrost evaporator 11 in a conventional manner. For this purpose, the defrost heater 16, for example, operated as long until the temperature sensor 24 at the evaporator 11 indicates a temperature above 0 ° C., which indicates that the evaporator 11 is completely free from ice. The flaps 13, 14 are meanwhile closed.

If it is determined in step S7 that the defrost termination condition is met, the defrost heater 16 will still operate, and the fan 18 will operate and the door 14 will be opened to vent air to the defrost heater 16 and heated by her evaporator 11 heated to blow in the flexible compartment 6.

The amount of time the defrost heater 16 is expected to run to bring the flexible shelf 6 to the new setpoint temperature T _soll can be estimated in advance from the performance of the defrost heater 16, the heat capacity of the flexible shelf 6, and the difference between the old and new setpoint temperatures , and a predetermined fraction of this time period is set as the duration t1 of a first switch-on phase of defrost heater 16 and fan 18.

If it is determined in step S9 that this first switch-on phase has elapsed, defrost heater 16 and fan 18 are switched off in step S10 in order to allow temperature compensation between different regions of flexible compartment 6 in the subsequent switch-off phase of duration t '.

If it turns out in the turn-off phase (S12) that the new target temperature has been reached, the process ends and the display element of the user interface is switched off. If this does not happen, then, when the end of the switch-off phase is reached in step S11, a new switch-on phase is initiated (S13), whose duration t2, however, is shorter than t1. If the end of this switch-on phase is detected in step S14, the fan and the defrost heater are turned off again, and the process returns to step S11. Thus switch-off and short switch-on phases alternate with each other until the new setpoint temperature T setpoint _is reached.

Ideally, this should be done without any need for cooling in a storage compartment in the meantime, as the method of cooling the compartment is used Fig. 2 interrupted, the evaporator must be cooled down and then reheated to the Heating the flexible compartment 6 to continue. If such an interruption is necessary, the method can then be resumed in step S2, so that if the difference .DELTA.T between the current temperature and target temperature is less than .DELTA.T _min at the resumption time, a renewed heating of the evaporator chamber is omitted and the still heating the compartment 6 is left to the influx of ambient heat through the walls of the compartment.

REFERENCE NUMBERS

1

corpus

2

door

3

door

4

door

5

freezer

6

flexible compartment

7

evaporator chamber

8th

rear wall

9

horizontal partition

10

Normal refrigeration compartment

11

Evaporator

12

vertical partition

13

flap

14

flap

15

wall

16

defrost heater

17

distribution area

18

Fan

19

control unit

20

temperature sensor

21

temperature sensor

22

temperature sensor

23

temperature sensor

24

compressor

Claims (9)

1. Refrigeration appliance, in particular household refrigeration appliance, having a flexible compartment (6) which can be operated at different temperatures selectively as a refrigerator compartment or as a freezer compartment, an evaporator (11) accommodated in an evaporator chamber (7) separated from the compartment (6), a defrost heater (16) assigned to the evaporator (11) and a fan (18) for driving an air flow between the evaporator chamber (7) and the compartment (6), wherein a control unit (19) is designed to simultaneously operate the fan (18) and defrost heater (16) in a heat-up mode phase (S8-S12) after increasing (S1) a target temperature (T_soll ) of the flexible compartment (6) in order to heat up the flexible compartment (6), characterised in that in a heat-up mode phase (S8-S12) switch-on phases (S8-S10, S13-S15), in which the fan (18) and defrost heater (16) are in operation, alternate with switch-off phases (S15-S13), in which the fan (18) and defrost heater (16) are not in operation.
2. Refrigeration appliance according to claim 1, characterised in that the control unit is designed to control a defrost process (S6, S7) prior to simultaneously operating the fan (18) and the defrost heater (16).
3. Refrigeration appliance according to claim 1 or 2, characterised in that a switch-on phase (S8-S10) is longer at the start of the heat-up mode phase (S8-S12) than a switch-on phase (S13-15) toward the end of the heat-up mode phase.
4. Refrigeration appliance according to one of the preceding claims, characterised in that the control unit (19) is designed to increase the target temperature at a previously fixed point in time.
5. Refrigeration appliance according to one of the preceding claims, characterised by a display element for displaying the end of the heat-up mode phase.
6. Refrigeration appliance according to one of the preceding claims, characterised in that it has at least one further compartment (5), which can be cooled by the evaporator (11).
7. Method for operating a refrigeration appliance with a flexible compartment (6) which can be operated at different temperatures selectively as a refrigerator compartment or as a freezer compartment, an evaporator (11) accommodated in an evaporator chamber (7) separated from the compartment (6), a defrost heater (16) assigned to the evaporator (11) and a fan (18) for driving an air flow between the evaporator chamber (7) and the compartment (6), having the steps:

   a) increasing (S1) a target temperature (T_soll ) of the compartment (6) and in a heat-up mode phase alternately

   d) switch-on phases in which the fan (18) and defrost heater (16) are in operation and switch-off phases in which the fan (18) and defrost heater (16) are not in operation, in order to heat the compartment (6) to the target temperature (T_soll ).
8. Method according to claim 7, in which after step a) and before step d) a step (S6, S7) c) of defrosting the evaporator (11) is carried out without the fan (18) by operating the defrost heater (16).
9. Method according to claim 7 or 8, in which after step a) and before step d) a step b) of precooling (S5) a further compartment (5) takes place.

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