DE102021212364A1 - Refrigeration device and method for defrosting an evaporator in a refrigeration device - Google Patents

Abstract

A refrigeration appliance, in particular a household refrigeration appliance, comprises a storage compartment which is delimited in relation to a vertical direction by a base and a top wall arranged at a distance from the base and in relation to a depth direction by a rear wall extending between the base and the top wall, one on an outer surface The rear wall arranged evaporator assembly with an evaporator and a fan, which is designed to draw in an air mass flow from the storage compartment through an exhaust air opening located in the area of the floor, to conduct it via the evaporator and through at least one in the vertical direction in the direction of the top wall from the exhaust air opening to eject the objectionable supply air opening into the storage compartment, and a control device signal-connected to the fan for operating the fan, the control device being set up to interrupt a circulation of refrigerant through the evaporator in order to defrost ice on the evaporator and to interrupt the air mass flow conveyed by the fan during defrosting to vary between a first value and a second value which is reduced compared to the first value.

Description

TECHNICAL AREA

The present invention relates to a refrigeration appliance, in particular a household refrigeration appliance such as a refrigerator, a chest freezer or a freezer or a fridge-freezer combination, and a method for defrosting an evaporator in a refrigeration appliance.

STATE OF THE ART

In the field of household refrigeration appliances, so-called no-frost refrigeration appliances are known, in which air is circulated between a storage compartment and an evaporator chamber, in which a refrigerant evaporator is arranged, by means of a blower or fan.

In the JP H09 318231 A discloses a refrigeration appliance having a horizontally oriented evaporator and a fan for circulating air across the evaporator, wherein the circulation of refrigerant through the evaporator is stopped and the fan continues to operate to defrost the evaporator.

Depending on the orientation of the evaporator with respect to the direction of gravity and depending on the direction of flow of the air in or against the direction of gravity over the fan, the air flow helps or hinders the removal of water droplets during the defrosting process.

SUMMARY OF THE INVENTION

It is one of the objects of the present invention to provide improved solutions for defrosting an evaporator of a refrigerator.

According to the invention, this object is achieved by a refrigeration device having the features of claim 1 and by a method having the features of claim 8 .

According to a first aspect of the invention, a refrigeration appliance, in particular a household refrigeration appliance such as a refrigerator, a chest freezer or a freezer or a fridge-freezer combination, comprises a storage compartment which, in relation to a vertical direction, is formed by a floor and a top wall arranged at a distance from the floor and is delimited with respect to a depth direction by a rear wall extending between the floor and the top wall, an evaporator assembly which is arranged on an outer surface of the rear wall and has an evaporator and a fan, which is designed to direct an air mass flow out of the storage compartment through an air mass flow in the area of the exhaust air opening located on the floor, to direct it via the evaporator and to expel it into the storage compartment through at least one supply air opening which is spaced apart from the exhaust air opening in the vertical direction in the direction of the ceiling wall, and a control device signal-connected to the fan for operating the fan, the control device being set up to to interrupt a circulation of refrigerant through the evaporator to defrost ice on the evaporator and to vary the air mass flow conveyed by the fan during defrosting between a first value and a second value that is reduced compared to the first value.

According to a second aspect of the invention, a method for defrosting an evaporator in a refrigeration appliance, in particular in a household refrigeration appliance, includes circulating refrigerant through the evaporator, conveying an air mass flow, with a fan sucking in the air mass flow from a storage compartment of the refrigeration appliance, against the direction of gravity via the evaporator and ejects again into the storage compartment, stopping the circulation of the refrigerant through the evaporator and, in particular after stopping the circulation of the refrigerant through the evaporator, varying the air mass flow circulated by the fan between a first value and a value opposite to the first value decreased second value.

One idea underlying the invention is to defrost an evaporator of a refrigeration appliance, which extends along the direction of gravity or along a vertical direction of the refrigeration appliance and is surrounded by an air mass flow counter to the direction of gravity, to interrupt the circulation of the refrigerant through the evaporator and the air mass flow , which is conveyed by a fan against the direction of gravity over the evaporator to vary, that is, to temporarily reduce compared to a predetermined operating value. When the refrigeration device is in operation, the vertical direction is aligned along the direction of gravity. Due to the interruption of the refrigerant circulation, the evaporator is heated by the air mass flow sucked in from the storage compartment of the refrigeration device, so that ice that has formed on the surface of the evaporator changes to a liquid aggregate state. In the process, liquid droplets are formed. The weight force resulting from the mass of the droplets acts in the direction of gravity on the droplets formed. Furthermore, due to the flow direction of the air mass flow, a force directed counter to the direction of gravity acts on the droplets, which counteracts the droplets flowing off in the direction of gravity.

The inventive partial reduction of the air mass flow from the first to the second value or the variation of the air mass flow between the first and the second value reduces the force acting against the direction of gravity at least temporarily, which facilitates the removal of liquid from the surface of the evaporator. Since the liquid is transported away from the evaporator more quickly, the heat transfer between the ice that is still on the evaporator and the air mass flow is improved. This speeds up the defrosting process overall.

Advantageous refinements and developments result from the dependent claims referring back to the independent claims in connection with the description.

According to some specific embodiments, it can be provided that the control device is set up to vary the speed of the fan in order to vary the air mass flow. The speed of the blower can thus be varied in order to vary the air mass flow. The speed of the fan can advantageously be varied quickly and precisely in a simple manner and is proportional to the air mass flow.

According to some specific embodiments, it can be provided that the control device is set up to vary the air mass flow continuously between the first and the second value. In the method, the air mass flow can be varied continuously between the first and the second value. For example, the air mass flow can be increased and decreased in waves. Accordingly, the varying occurs continuously, so that the air mass flow is not constant as long as the blower is in operation.

According to some specific embodiments, it can be provided that the control device is set up to keep the air mass flow constant at the first value over a first period of time and constant at the second value over a second period of time. In the method, the air mass flow can be kept constant at the first value over a first period of time and constantly at the second value over a second period of time.

According to some specific embodiments, it can be provided that the control device is set up to increase the air mass flow continuously, e.g. linearly, from the first value to the second value and/or to decrease it continuously, e.g. from the second value to the first value. Similarly, in the method, the air mass flow can be continuously increased from the first value to the second value and/or continuously reduced from the second value to the first value. The air mass flow can optionally be kept constant at the first or the second value between the increase and the decrease.

According to some specific embodiments, it can be provided that the control device is set up to temporarily interrupt the operation of the fan during defrosting. The operation of the fan can thus be temporarily interrupted during defrosting. In this case, the second value of the air mass flow can therefore be 0. For example, the air mass flow conveyed by the blower can be varied continuously, e.g. in waves, between “0” and a maximum value, e.g. the first value, with the second value “0” being maintained for a predetermined period of time. Similarly, the second value “0” can also be set for a predetermined (second) period after the air mass flow has steadily decreased to the second value or after the first value has been kept constant over the first period. The temporary switching off or interruption of the operation of the blower offers the advantage that the air mass flow is temporarily interrupted and thus the force acting on the droplets counter to the direction of gravity as a result of the air mass flow is eliminated. This further facilitates the drainage of the droplets.

According to some embodiments, it can be provided that the storage compartment has a warm storage area with an exhaust air opening, a cold storage area with an air inlet opening above it, and a cooling area with an air inlet opening above it. In this arrangement, the refrigerated area can also be cooled during defrosting and the required temperature in the cold storage area can be maintained.

According to some embodiments, it can be provided that the evaporator forms a refrigerant circuit together with a compressor and a condenser, the compressor being set up to circulate refrigerant through the evaporator and the condenser, so that the refrigerant evaporates at the evaporator while absorbing heat and at the condenser under Heat emission to the environment condenses, wherein the control device is connected to the compressor and/or a guide valve in a signal-conducting manner and is set up to interrupt operation of the compressor during defrosting and/or to switch the guide valve in order to circulate refrigerant through the to interrupt the evaporator. In the method, stopping the circulation of the refrigerant can be a shutdown a compressor coupled to the evaporator and/or switching a guide valve.

According to some specific embodiments, it can be provided that the air mass flow is varied after the circulation of the refrigerant has been interrupted without switching on an additional heater. Thus, the energy expenditure for defrosting can be further reduced.

The features and advantages disclosed herein in connection with the refrigeration device are also disclosed in connection with the method and vice versa. In particular, the method according to the second aspect of the invention can be implemented in the refrigeration device according to the first aspect of the invention. For example, the control device can be set up to cause the refrigeration device to carry out the method.

character list

• 1 eine vereinfachte, schematische Schnittansicht eines Kältegeräts gemäß einem Ausführungsbeispiel der Erfindung;
• 2 ein Ablaufdiagramm eines Verfahrens zum Abtauen eines Verdampfers in einem Kältegerät gemäß einem Ausführungsbeispiel der Erfindung;
• 3 ein Diagramm, in welchem eine zeitliche Variation eines Luftmassenstroms dargestellt ist, wie sie in einem Verfahren und/oder einem Kältegerät gemäß einem Ausführungsbeispiel der Erfindung vorgenommen wird;
• 4 ein Diagramm, in welchem eine zeitliche Variation eines Luftmassenstroms dargestellt ist, wie sie in einem Verfahren und/oder einem Kältegerät gemäß einem weiteren Ausführungsbeispiel der Erfindung vorgenommen wird;
• 5 die auf ein Flüssigkeitströpfchen an einem Verdampfer wirkenden Kräfte, wenn der Verdampfer entgegen der Schwerkraftrichtung mit einem ersten Luftmassenstrom umströmt wird; und
• 6 die auf ein Flüssigkeitströpfchen an einem Verdampfer wirkenden Kräfte, wenn der Verdampfer entgegen der Schwerkraftrichtung mit einem zweiten, im Vergleich zum ersten Luftmassenstrom geringeren Luftmassenstrom umströmt wird.

The invention is explained below with reference to the figures of the drawings. From the figures show:

• 1 a simplified, schematic sectional view of a refrigerator according to an embodiment of the invention;
• 2 a flowchart of a method for defrosting an evaporator in a refrigeration device according to an embodiment of the invention;
• 3 a diagram in which a temporal variation of an air mass flow is shown, as is carried out in a method and / or a refrigeration device according to an embodiment of the invention;
• 4 a diagram in which a temporal variation of an air mass flow is shown, as is carried out in a method and/or a refrigeration device according to a further exemplary embodiment of the invention;
• 5 the forces acting on a liquid droplet on an evaporator when a first air mass flow flows around the evaporator counter to the direction of gravity; and
• 6 the forces acting on a liquid droplet on an evaporator when a second air mass flow, which is lower than the first air mass flow, flows around the evaporator counter to the direction of gravity.

In the figures, the same reference symbols designate identical or functionally identical components, unless otherwise stated.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

1 shows an example and in a schematic way a refrigerator 100, for example in the form of a refrigerator. In general, the refrigeration device 100 can be a household refrigeration device. As in 1 shown schematically, the refrigeration device 100 has a storage compartment 1 , a refrigerant circuit 130 with an evaporator assembly 3 and a control device 9 .

The storage compartment 1 is provided for accommodating refrigerated goods, such as food, beverages, medicines or the like. For example, the storage compartment 1 can be formed by an interior space bounded by an essentially rectangular storage compartment container 101 . In general, the storage compartment 1 is delimited with respect to a vertical direction V by a base 10 and a top wall 11 arranged at a distance from the base 10 . The storage compartment 1 is delimited by a rear wall 12 with respect to a depth direction T running transversely to the vertical direction V. The rear wall 12 can extend in particular between the floor 10 and the top wall 11, as is shown in 1 is shown schematically. With respect to a transverse direction C extending transversely to the depth direction T and to the vertical direction V, the storage compartment 1 can also be delimited by side walls 13 extending between the top wall 11 and the bottom 10 . As in 1 As further shown, the storage compartment 1 may be accessible on a side opposite the rear wall 12 through an access opening 1A. For example, the access opening 1A may be defined by the side walls 12, the floor 10 and the top wall 11. The access opening 1A thus preferably extends uninterruptedly between the floor 10 and the top wall 11. The access opening 1A can also be covered by a door 8.

As in 1 shown schematically, a first intermediate floor 16A arranged at a distance from the floor 10 in relation to the vertical direction V can be provided in the storage compartment 1 . The first intermediate floor 16A can extend in particular from the rear wall 12 in the depth direction T into the storage compartment 1 . A warm storage area 15 extends between the floor 10 and the first intermediate floor 16A, or the warm storage area 15 is delimited in relation to the vertical direction by the floor 10 and a first intermediate floor 16A.

As in 1 is also shown, a second intermediate floor 16B arranged at a distance from the first intermediate floor 16A in relation to the vertical direction V can be provided in the storage compartment 1 . The second intermediate floor 16B can extend in particular from the rear wall 12 in the depth direction T into the storage compartment 1 . A cold storage area 16, which is provided for cooling to a temperature which is at least 1.5 Kelvin below the average temperature in the storage compartment, extends between the first and the second intermediate floor 16A, 16B. Thus, the first and the second intermediate floor 16A, 16B delimit the cold storage area 16 in relation to the vertical direction V.

A cold storage area 17 can extend in the storage compartment 1 in the vertical direction V from the second intermediate floor 16B. In particular, the cold storage area 17 can be delimited with respect to the vertical direction V by the second intermediate floor 16B and the top wall 11 . As in 1 is also shown schematically, it can be provided that several shelves 19 are provided in the cold storage area 17, which are arranged spaced apart from one another in the vertical direction V. As in 1 shown by way of example, the shelves 19 can extend in the depth direction T from the rear wall 12 into the storage compartment 1 .

Since the access opening 1A, as explained above, is preferably formed continuously between the floor 10 and the top wall 11, the hot storage area 15, the cold storage area 16 and the cold storage area 17 are each accessible through the access opening 1A, e.g. for putting in or removing chilled goods.

In the 1 The division of storage compartment 1 shown into warm storage compartment 15, cold storage compartment and cold storage area 17 is purely exemplary and the invention is not limited thereto.

As in 1 is also shown schematically, the rear wall 12 can have a first air inlet opening 18A, which is arranged with respect to the vertical direction V between the first and the second intermediate floor 16A, 16B. Furthermore, the rear wall 12 can have a multiplicity of second air inlet openings 18B, which are spaced apart from one another in the vertical direction V and, with respect to the vertical direction V, are arranged between the second intermediate floor 16B and the top wall 11 . For example, it can be provided that at least one second air inlet opening 18B is arranged between each two adjacent shelves 19, as is shown in 1 is shown schematically. In principle, it is also conceivable that only a second supply air opening 18B is provided in the rear wall 12 , which is arranged between the second intermediate floor 16B and the top wall 11 in relation to the vertical direction V. Furthermore, as in 1 shown schematically, an exhaust air opening 18C is formed in the rear wall 12, which is arranged with respect to the vertical direction V between the floor 10 and the first intermediate floor 16A. In general, the rear wall 12 has an exhaust air opening 18C located in the area of the base 10 and at least one air supply opening 18A, 18B spaced apart from the exhaust air opening 18C in the vertical direction V in the direction of the top wall 11 .

As in 1 shown schematically, the air inlet openings 18A, 18B and the air outlet opening 18C each extend between an inner surface 12a of the rear wall 12, which is oriented towards the storage compartment 1, and an outer surface 12b of the rear wall 12, which is opposite to the inner surface 12a. This forms the first air inlet opening 18A a fluidically conductive connection between the cold storage area 16 and an outside or rear side defined by the outer surface 12b of the rear wall 12. FIG. In the same way, the second air inlet openings 18B form a fluidically conductive connection between the cold storage area 17 and the rear side, and the exhaust air opening 18C forms a fluidically conductive connection between the warm storage area 15 and the rear side. In general, the exhaust air opening 18C and the at least one air supply opening 18A, 18B form a fluidically conductive connection between the storage compartment 1 and an outside or rear side defined by the outer surface 12b of the rear wall 12 .

On the back or on the outer surface 12b of the rear wall 12, for example, an air distribution channel 2 can extend. As in 1 is shown schematically, the optional air distribution duct 2 runs along the vertical direction V. In general, the air distribution duct 2 is formed by a cavity on the back of the rear wall 12, which has an extension in the vertical direction 2. As in 1 shown schematically, the air distribution duct 2 can extend with respect to the vertical direction V from a lower end, which is located between the first air inlet opening 18A and the exhaust air opening 18C, to a last second air inlet opening 18B with respect to the vertical direction V. As in 1 shown schematically and purely by way of example, the air distribution channel 2 can be delimited or defined in the area of the cold storage area 16 , for example by the rear wall 12 and the evaporator assembly 3 . As in 1 shown, the first air supply opening 18A extends between the air distribution duct 2 and the cold storage area 16. In the area of the cold storage area 17, the air distribution duct 2 can be installed, for example, through the rear wall 12 and an outer cover 5 or, as in FIG 1 exemplified by an optional les insulating part or an insulating plate 4 and the outer cover 5 can be defined. In general, the air distribution channel 2 is connected to the second air intake openings 18B.

The optional insulating plate 4 is formed from a thermally insulating material and is arranged on the outer surface 12b of the rear wall 12, in particular between the outer surface 12b of the rear wall 12 and an inner surface 5a of the outer cover 5. An outer surface 4b of the insulating plate 4 facing the inner surface 5a of the outer cover 5 can be provided with at least one groove 41 . The groove 41 runs at least in regions along the vertical direction V, as shown in 1 is recognizable. For example, a first groove 41A running in the vertical direction V can be provided. Optionally, one or more second grooves (not shown), which can run in the transverse direction C in particular, can branch off from the first groove 41A. As in the 1 Further, as shown, in each groove 41A, a through hole 43 penetrating the insulating board 4 completely may be formed. For example, a through hole 43 can be formed for every second intake air opening 18B. As in 1 shown schematically, each through hole 43 can be arranged in alignment with a respective second air inlet opening 18B. Thus, the duct 2 can be defined by the groove 41 and the inner surface 5a of the outer cover 5, and the groove 41 is connected through a respective through hole 43 to a respective second intake air opening 18B.

The evaporator assembly 3 has an evaporator 30 and a fan 33 and an optional insulating part 35 . As in 1 shown schematically, the evaporator 30 is part of the refrigerant circuit 130 which, in addition to the evaporator 30 , has a compressor 131 , a throttle (not shown), a condenser 132 and an optional guide valve 133 . The compressor 131 serves to circulate refrigerant in the refrigerant circuit 130 , an inlet of the compressor 131 being connected to the evaporator 30 and an outlet of the compressor 131 being connected to the condenser 132 . The throttle is arranged between the condenser 132 and the evaporator 30 . The guide valve 133 can be arranged in particular between the condenser 132 and the evaporator 30, as in 1 shown as an example. The guide valve 133 can be switched between a first position, in which the guide valve 133 permits an inflow of refrigerant into the evaporator 30 , and a second position, in which the guide valve 133 blocks an inflow of refrigerant into the evaporator 30 . In the evaporator 30, the refrigerant is evaporated while absorbing heat. The compressor 131 sucks the gaseous refrigerant from the evaporator 30 and conveys the compressed refrigerant into the condenser 132, where it condenses, giving off heat to the environment. The pressure of the refrigerant is reduced again at the throttle.

As in 1 shown schematically, the evaporator assembly 3 is arranged on the outer surface 12b of the rear wall 12, for example in the area of the bottom 10. As in FIG 1 shown, the optional insulating part 35 can be arranged in particular between the rear wall 12 and the evaporator 30 . It is optionally provided that the evaporator 30 is arranged in the area of the warm storage area 15 and the insulating part 35 is located at least in the area of the warm storage area 15 between the evaporator 30 and the rear wall 12 .

The evaporator assembly 3 is fluidically connected to the exhaust air opening 18C. For example, the evaporator assembly 3 can have a suction port 31 formed by a recess in the insulating part 35 extending in the depth direction T, as shown in FIG 1 is shown schematically. The suction connection can be located, for example, in an area of the evaporator assembly 3 facing the base 10, as in FIG 1 shown, the suction port 31 can be positioned in alignment with the exhaust air opening 18C of the rear wall 12, for example. Generally, suction port 31 of evaporator assembly 3 is connected to exhaust port 18C.

The evaporator assembly 3 is also connected in a fluidically conductive manner to the at least one air inlet opening 18A, 18B. For this purpose, the evaporator assembly can have a pressure connection 32 . The pressure connection 32 can be arranged at a distance from the suction connection 31 in relation to the vertical direction V and can be positioned in particular in an end region of the evaporator assembly 3 facing the top wall 11 . For example, the pressure connection 32 can be designed as a recess in the insulating part 35 that extends in the depth direction T and opens into the air distribution duct 2, as shown in FIG 1 shown schematically. in the in 1 Refrigeration device 100 shown as an example, the pressure connection 32 is fluidically conductively connected to the air distribution channel 2, which in turn is fluidically conductively connected to the air inlet openings 18A, 18B.

The evaporator 30 can be arranged, for example, in an evaporator chamber of the evaporator assembly 3 , which is connected to the storage compartment 1 , in particular to the warm storage area 15 , through the suction connection 31 , and to the air distribution duct 2 through the pressure connection 32 . The evaporator chamber can be delimited, for example, by the insulating part 35 and the outer cover 5, as in FIG 1 shown schematically. Alternatively, it would also be conceivable for the evaporator chamber to be completely surrounded by an insulating part 35 . Generally, the evaporator 30 is on the rear side of the rear wall 12 arranged. As in 1 It can also be seen that the evaporator 30 is aligned along the vertical direction V or has the air sucked in by the fan 33 flowing around it along the vertical direction V.

The blower 33 can be arranged, for example, between the evaporator 30 and the pressure connection 32, for example in the pressure connection 32, as in FIG 1 shown schematically and purely as an example. In particular, the blower 33 is arranged and configured to draw in an air mass flow from the storage compartment 1 through the exhaust air opening 18C, in particular via the suction connection 31, to conduct it via the evaporator 30 and to eject it through the at least one air inlet opening 18A, 18B into the storage compartment 1. For example, the blower 33 can eject the air through the pressure connection 32 into the air distribution channel 2, from where it is conducted into the storage compartment 1 through the air inlet openings 18A, 18B.

At the in 1 In the purely exemplary division of storage compartment 1 with warm storage area 15, cold storage area 16 and cold storage area 17, warm air in warm storage area 15 is thus sucked out of storage compartment 1 by means of blower 33 through exhaust air opening 18C during normal cooling operation. In 1 this is shown symbolically by the arrows P1 shown in dash-dotted lines. The warm air is passed over the evaporator 30 where heat is extracted from it. The air cooled by the evaporator 30 is conveyed by means of the fan 33 through the pressure connection 32 into the air distribution duct 2 and expelled from there through the first air inlet opening 18A directly into the cold storage area 16 and through the at least one second air inlet opening 18B into the cold storage area 17, such as this in 1 is represented symbolically by the dashed arrows P2. As in 1 is shown, the first air inlet opening 18A along a flow path along which the air flows in the air distribution channel 2 can have a smaller distance from the pressure connection 32 of the evaporator assembly 3 than the at least one second air inlet opening 18B. For example, the first air inlet opening 18A can be arranged in the area of the pressure connection 32, as shown in FIG 1 shown schematically. The air thus covers a longer distance on its way to the second air inlet opening(s) 18B, which means that the air is already warming up. This makes it easier to achieve a temperature difference between the cold storage area and the cold storage area.

The control device 9 is designed as an electronic control device and can have, for example, a processor (not shown) and a data memory (not shown) that can be read by the processor. For example, the processor may include a CPU, an ASIC, an FPGA, or the like. The data store may include a non-volatile data storage medium such as a hard drive, SD memory, flash memory, or the like. Software that can be executed by the processor and causes the processor to output control signals S can be stored in the data memory. The control device 9 is in 1 shown only symbolically as a block and is connected to the blower 32 and the refrigerant circuit 130 in a signal-conducting manner, e.g. to the compressor 131 and/or the guide valve 133. The control device 9 is generally designed to output control signals S for operating the blower 32, e.g To vary the speed of the fan 32 and thus the air mass flow conveyed by the fan 32. Furthermore, the control device 9 can be designed to output control signals S for operating the compressor 131, for example for varying its capacity, and/or for switching the valve 131 between the first and the second position.

As described above, during the normal cooling operation, warm air is drawn from the storage compartment 1 by the fan 32 and passed over the evaporator 30 . Since the air from the storage compartment 1 contains moisture, ice can form on the evaporator 30 . The evaporator 30 therefore has to be defrosted occasionally so that the refrigerant circuit 130 can work in an energy-efficient manner. A method M for defrosting an evaporator 30 in a refrigerator 100 is described below by way of example with reference to FIG 1 shown refrigeration device 100 is described, it being assumed that the vertical direction V is aligned along the direction of gravity G. In particular, the refrigeration device 100 is oriented in such a way that the base 10 is arranged at the bottom with respect to the direction of gravity G and the top wall 11 is arranged at the top.

2 shows a schematic flowchart of method M for defrosting evaporator 30. Method M is based on a state in which refrigerant M1 is circulated through evaporator 30, e.g. by means of compressor 131, and at the same time an air mass flow L through fan 33 is sucked in from a storage compartment 1 of the refrigeration device 100 , directed against the direction of gravity G via the evaporator 30 and ejected back into the storage compartment 1 . This corresponds to the normal operation described above.

In step M3, the circulation of the refrigerant through the evaporator 30 is interrupted. For example, the control device 9 can output a signal S to the compressor 131 in order to interrupt the circulation of the refrigerant turn it off and/or output a signal S to valve 133 to switch it from the first to the second position. Thus, although air is still directed over the evaporator 30 , however, no refrigerant is circulated through the evaporator 30 . As a result, the evaporator 30 is heated by the air coming from the storage compartment 1 and the ice on the evaporator 30 is thawed. As a result, liquid droplets D form on the surface of the evaporator 30.

5 shows a simplified detailed view of the surface of the evaporator 30 in a state in which a liquid droplet D has formed on the surface of the evaporator 30 and the fan 33 is still operated at a first speed or the air mass flow L has a first value w1. The weight F1 resulting from the mass of the droplet D acts on the droplet D in the direction of gravity G. Furthermore, a force F2 directed against the direction of gravity G due to the flow direction of the air mass flow L acts on the droplets, which causes the droplets to flow off in the direction of gravity G counteracts.

In a further step M4 of the method, the air mass flow L circulated by the fan 33 is therefore varied between a first value w1 and a second value w2, which is lower than the first value w1. For this purpose, the control device 9 outputs a signal S to the fan 33 in order to reduce the air mass flow L, for example by reducing the speed of the fan 33 . Due to the constant or temporally unchanged flow cross section in the region of the compressor 30, the flow speed is also reduced by the reduction in the air mass flow L. Consequently, the force F2 exerted by the air flow L on the droplet D and directed counter to the direction of gravity G is also reduced. As in 6 1, a resultant force FR thereby acts in the direction of gravity, which promotes the flow of the droplet D from the evaporator 30.

The control device 9 can operate the blower 33, for example, in such a way that the air mass flow L is varied continuously between the first and the second value w1, w2. 3 shows, purely by way of example, a continuous, wavy variation between the first value w1 and the second value w2, which is shown in 3 is equal to 0 purely by way of example. This means that it can optionally be provided that the operation of the blower 33 is temporarily interrupted during defrosting. The air mass flow L is in 3 plotted on the ordinate in a diagram with time Z plotted on the abscissa.

Alternatively, the control device 9 can also operate the blower 33 in such a way that the air mass flow L is kept constant at the first value w1 over a first time period z1 and at the second value w2 over a second time period z2, as is shown schematically and by way of example in 4 diagram shown. As in 4 shown by way of example, the second value w2 can also be equal to 0 in this case. That is, it is optionally possible for the control device 9 to temporarily interrupt the operation of the blower 33 . In 4 a simple way of operating the blower 33 is thus shown, which is operated constantly at a predetermined speed in the first time period z1 and is switched off in the second time period z2.

Furthermore, it would also be conceivable for the control device 9 to operate the fan 33 in such a way that the air mass flow L is continuously reduced from the first value w1 to the second value w2, e.g. by reducing the speed of the fan 33 linearly and/or continuously from the second Value w2 is increased to the first value w1, e.g. by linearly increasing the speed of fan 33. It is also possible here for the mass flow to be kept constant at the respective value for a certain period of time after it has been reduced to the second value w2 or after it has been increased to the first value w1. In this case, too, the operation of the fan 33 can be temporarily interrupted during defrosting, e.g. in order to set the second value w2 to 0.

The above, in particular with reference to the 3 and 4 Explained options for the temporal variation of the air mass flow L, which is promoted by the fan 33 are purely exemplary and not exhaustive. In particular, other time profiles of the air mass flow L during defrosting are also conceivable. In general, the control device 9 for defrosting ice on the evaporator 30 varies the air mass flow L conveyed by the fan 33 during defrosting between a first value w1 and a second value w2, which is lower than the first value w1.

Optionally, the variation M4 of the air mass flow L can take place after the interruption M3 of the circulation of the refrigerant, in particular without switching on an additional heater.

Although the present invention has been explained above by way of example using exemplary embodiments, it is not limited thereto but can be modified in many different ways. In particular, combinations of the above exemplary embodiments are also conceivable.

Reference List

1

storage compartment

1A

access opening

2

air distribution duct

3

evaporator assembly

4

insulation panel

4b

outer surface of the insulation board

5

outer cover

5a

inner surface of the outer cover

8th

door

9

control device

10

Floor

11

ceiling wall

12

back panel

12a

inner surface of the back wall

12b

outer surface of the back wall

13

sidewalls

15

warm storage area

16

cold storage area

16A

first mezzanine

16B

second intermediate floor

17

cold storage area

18A

first intake air opening

18B

second air intake

18C

exhaust vent

19

shelves

30

Evaporator

31

suction port

32

pressure connection

33

fan

35

insulating part

41

groove

41A

first groove

43

through hole

100

refrigeration device

101

container

130

Refrigerant circulation

131

compressor

132

condenser

133

pilot valve

C

transverse direction

D

droplet

F1

weight force

F2

force directed against the direction of gravity

FR

resulting power

G

direction of gravity

M

Proceedings

M1-M4

process steps

P1

Arrow

p2

Arrow

T

depth direction

V

vertical direction

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• JP H09318231A [0003]

Claims (15)

Refrigeration appliance (100), in particular domestic refrigeration appliance, comprising: a storage compartment (1) which, in relation to a vertical direction (V), is provided by a floor (10) and a top wall (11) arranged at a distance from the floor (10) and in relation to a The depth direction (T) is delimited by a rear wall (12) extending between the base (10) and the top wall (11); an evaporator assembly (3) arranged on an outer surface (12b) of the rear wall (12) with an evaporator (30) and a fan (33), which is designed to blow an air mass flow out of the storage compartment (1) through a 10) located exhaust air opening (18C), to conduct it via the evaporator (30) and through at least one air supply opening (18A, 18B) spaced apart from the exhaust air opening (18C) in the vertical direction (V) in the direction of the top wall (11) into the storage compartment (1) to expel; and a control device (9) signal-connected to the fan (33) for operating the fan (33); characterized in that the control device (9) is set up to defrost ice on the evaporator (30) to interrupt a circulation of refrigerant through the evaporator (30) and the air mass flow (L) conveyed by the fan (33) during defrosting between a first value (w1) and a second value (w2) which is reduced compared to the first value (w1). Refrigeration device (100) after claim 1 , characterized in that the control device (9) is set up to vary the speed of the fan (33) to vary the air mass flow (L). Refrigeration device (100) after claim 1 or 2 , characterized in that the control device (9) is set up to vary the air mass flow (L) continuously between the first and the second value (w1, w2). Refrigeration device (100) after claim 1 or 2 , characterized in that the control device (9) is set up to keep the air mass flow (L) constant at the first value over a first period (z1) and constant at the second value over a second period (z2). Refrigeration appliance (100) according to one of the preceding claims, characterized in that the control device (9) is set up to temporarily interrupt the operation of the fan (33) during defrosting. Refrigerating appliance (100) according to one of the preceding claims, characterized in that the storage compartment (1) has a warm storage area (15) with an exhaust air opening (18C), above it a cold storage area (16) with an inlet air opening (18A), and above that a cooling area (17 ) having an air inlet opening (18B). Refrigeration appliance (100) according to one of the preceding claims, characterized in that the evaporator (30) together with a compressor (131) and a condenser (132) forms a refrigerant circuit (130), the compressor (131) being set up to refrigerant circulate through the evaporator (30) and the condenser (131), so that the refrigerant evaporates at the evaporator (30) while absorbing heat and condenses at the condenser (132) while releasing heat to the environment, the control device (9) communicating signals with the compressor (131) and/or a guide valve (133) and is set up to interrupt operation of the compressor (131) during defrosting and/or to switch the guide valve (133) in order to circulate refrigerant through the evaporator ( 30) to interrupt. Method (M) for defrosting an evaporator (30) in a refrigerator (100), comprising: circulating (M1) refrigerant through the evaporator (30); Conveying (M2) an air mass flow (L), with a blower (33) sucking the air mass flow (L) out of a storage compartment (1) of the refrigeration device (100), directing it against the direction of gravity (G) over the evaporator (30) and returning it to the storage compartment (1) ejects; interrupting (M3) the circulation of the refrigerant through the evaporator (30); and Varying (M4) the air mass flow (L) circulated by the fan (33) between a first value (w1) and a second value (w2) which is reduced compared to the first value (w1). Procedure (M) according to claim 8 , wherein the speed of the fan (33) is varied to vary the air mass flow (L). Procedure (M) according to claim 8 or 9 , wherein the air mass flow (L) is varied continuously between the first and the second value (w1, w2). Procedure (M) according to claim 8 or 9 , wherein the air mass flow (L) is kept constant at the first value (w1) over a first time period (z1) and at the second value (w2) over a second time period (z2). Procedure (M) according to claim 8 or 9 , wherein the air mass flow (L) is steadily reduced from the first value (w1) to the second value (w2) and/or is steadily increased from the second value (w2) to the first value (w1). Process (M) according to any one of Claims 8 until 12 , the operation of the fan (33) is temporarily interrupted during defrosting. Process (M) according to any one of Claims 8 until 13 , wherein the varying (M4) of the air mass flow takes place after the interruption (M3) of the circulation of the refrigerant without switching on an additional heater. Process (M) according to any one of Claims 8 until 14 , wherein the interruption (M3) of the circulation of the refrigerant comprises switching off a compressor (131) coupled to the evaporator (30) and/or switching a guide valve (133).

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