DE102016220163A1 - Refrigeration unit with dehydrating function and operating method for it - Google Patents

Abstract

A refrigeration appliance comprises a storage compartment (6), a heat exchanger chamber (5) separated from the storage compartment (6), which contains a heat exchanger (7) which can be operated as an evaporator and a heater, a fan (8) for driving the air exchange between storage compartment (6) and Heat exchanger chamber (5), and a control unit (10) for controlling the operation of the heat exchanger (7), fan (8) and heating. The control unit (10) supports a dehydration mode in which the fan (8) is in simultaneous operation with the heater.

Description

The present invention relates to a refrigerator with a dehydrating function, i. a refrigerator that is capable of quickly and effectively dehulling stored material, particularly food, and a method for dehydrating material in the refrigeration appliance.

To some extent, almost all refrigerators tend to dry out refrigerated goods stored in them, since moisture evaporated by the refrigerated goods tends to precipitate on an evaporator, and thus the refrigerated goods are lost. This effect is especially pronounced in no-frost refrigerators, in which refrigerated goods and evaporators are spatially separated. In particular, unpackaged leafy vegetables tend therefore in a no-frost refrigerator to fast withering, on the other hand, the dehydration is not intense enough to allow a targeted dehydration of food.

In many no-frost refrigerators, a heater is provided in an evaporator chamber to defrost the evaporator. This heater is only in operation when the evaporator is not cooling at the same time, and even if a fan that circulates air between the evaporator chamber and storage compartment in the normal cooling mode is turned off.

A refrigerator in which a heater is arranged in a storage compartment to dry the contents of the storage compartment, is out JP 2008032392 known. However, the efficiency of this drying is limited. The placement of the heater in the storage compartment itself is not known, the drawing suggests the assumption that it is located at the bottom of the storage compartment. If the compartment is well filled, heat will only have to spread through the dry material to its surface to assist in evaporation; at the same time heat is lost downwards. An attachment of the heater above the dry material is also not satisfactory, since then the blown into the compartment cold air heater and dry material separated from each other.

Object of the present invention is to provide a refrigeration device that allows efficient drying of stored material with a simple structure, and to provide an operating method for such a refrigerator.

The object is achieved on the one hand by a refrigeration device with a storage compartment, a storage compartment separated from the heat exchanger chamber containing a heat exchanger operated as an evaporator and a heater, a fan for driving the air exchange between storage compartment and heat exchanger chamber, and a control unit for controlling the operation of heat exchanger, fan and heater, the control unit supports a drying mode in which the fan is in operation simultaneously with the heater. The heater can be used in this way not only to defrost the heat exchanger, but also to increase by heat input into the storage compartment there evaporation.

In dry mode, when heating phases in which the fan is simultaneously in operation with the heater alternate with cooling phases in which both the heat exchanger as evaporator and the fan are in operation, moisture released from the material in the storage compartment during a heating phase can condensed in a subsequent cooling phase on the heat exchanger and thus permanently removed from the material.

Between a cooling phase and a subsequent heating phase, the control unit should insert a defrosting phase in which the heater is operating without the fan so that frost thickened at the heat exchanger can thaw and drain away without an overflowing air stream being able to transport steam back to the storage compartment.

The control unit should then transition from the defrost phase to the heating phase, i. operate the fan if a rise in the temperature of the heat exchanger from a negative to a positive value indicates that the heat exchanger is completely defrosted.

The control unit can be connected to a hygrometer arranged in the storage compartment, in order to decide on the basis of its measurement data when the material in the storage compartment has dried sufficiently for the drying operation mode to be ended.

The duration of the defrosting phase allows a conclusion on the amount of precipitate deposited on the heat exchanger and thus on the degree of dryness of the material in the storage compartment; Therefore, the control unit may be suitably arranged to detect the duration of the defrosting phase and to end the dehydration mode when it falls below a threshold value. So the hygrometer in the storage compartment can be made superfluous.

This limit value can be fixed, ie the same for each drying process. It is more advantageous, however, to set it individually in proportion to the amount of material to be dehydrated and its drying properties for each dehydrating process. This can be done in a simple manner by measuring the duration of the first defrosting phase of a drying process and determining the limit value as a function of this duration, in particular as a predetermined fraction of it. So can be largely independent of the amount of material loaded into the storage compartment ensures that during the dehydration process the water content of the material is reduced according to the fraction.

The tendency of the material to release water is dependent on various factors, collectively referred to as the type of material, such as its biological origin (meat, mushrooms, fruits, leaves), the type of preparation (such as grown, coarse or fine crushed, with or without shell), etc. In order to assess this tendency and to be able to take into account when deciding on an end of the drying process, the control unit may be further connected to a storage compartment temperature sensor and configured to detect the rate of change of the temperature of the storage compartment. The rate of change may be determined as the difference between temperatures measured at a predetermined time interval; conversely, the time required for a given temperature change, in particular the duration of a heating phase and / or a cooling phase, can also be measured. The rate of change provides information about the amount of material; if this is related to the quantity of water discharged from the material in a cooling phase, this allows a conclusion to be drawn about the tendency of the material to release water and can be taken into account when determining a condition for terminating the drying process. In particular, the higher the tendency of the material to release water, the lower the threshold value for the duration of the defrosting phase.

In order to estimate the slope of the material for dispensing water, the control unit may further be connected to a user interface and configured to receive therefrom an input of a user about the nature of the material loaded in the storage compartment.

The control unit may also be connected to a scale which is arranged in the storage compartment in order to weigh the material loaded in the storage compartment. Such a scale can simplify dehydrating in different ways. Firstly, the weight of the material can be monitored continuously and the drying process can be terminated when the weight has decreased to a predetermined fraction of the initial weight of the material. The size of this fraction can, if known, be determined by the nature of the material. Conversely, from the weight and the speed of weight loss, it is possible to appropriately state the kind of the material and to set a target weight at which the dehydrating process is finished.

According to a preferred embodiment, the heat exchanger can be switched between operation as an evaporator and operation as heating.

For this purpose, the heat exchanger may be connected in a refrigerant circuit in series with at least one throttle point, whose passage rate is controlled by the control unit.

This refinement makes energy-efficient drying possible, in particular, when the refrigerating appliance has at least one additional storage compartment from which the heat released as heating during operation of the heat exchanger can be drawn off.

Conveniently, the control unit is further configured to send a message about the termination of the dehydration mode to a networked device, which then alerts its user to the end of the dehydration process by a signal, preferably an acoustic or a tactile signal. After issuing this signal, an explanation indicating the completion of the dehydration operation may be retrievable on a screen of the networked device. By then emptying and reloading the storage compartment, the user can take full advantage of the dehydrating capacity of the device while at the same time being able to move away from the refrigeration device during a dehydration process and do other work. A suitable utility for receiving the message and generating the signal, such as an app for a smartphone, may be included as an accessory to the refrigeration device of the invention or provided for download.

1. a) Einbringen des Materials in ein Lagerfach des Kältegeräts; und
2. b) Umwälzen von Luft zwischen dem Lagerfach und einer Kammer, in der die Luft abwechselnd in einer Heizphase beheizt und in einer Kühlphase durch einen als Verdampfer betrieben Wärmetauscher gekühlt wird.

On the other hand, the object is achieved by a method for drying material in a refrigeration appliance, in particular a refrigeration appliance as described above, with the steps

1. a) introducing the material into a storage compartment of the refrigeration device; and
2. b) circulating air between the storage compartment and a chamber in which the air is heated alternately in a heating phase and cooled in a cooling phase by a heat exchanger operated as an evaporator.

1. a) Einbringen des Materials in ein durch einen Wärmetauscher temperierbares Lagerfach des Kältegeräts;
2. b) Abwechselndes Betreiben des Wärmetauschers als Verdampfer und als Verflüssiger.

Another solution to the problem is a method for dehydrating material in a refrigerator with the steps

1. a) introducing the material into a heatable by a heat exchanger storage compartment of the refrigerator;
2. b) alternating operation of the heat exchanger as an evaporator and as a condenser.

• - Luftfeuchtigkeit im Lagerfach,
• - Dauer des Dörrvorgangs,
• - Gewicht des Materials,
• - Dauer einer Heiz-, Kühl- oder Abtauphase des Wärmetauschers, einen Grenzwert erreicht hat.

Dehydration can be stopped if at least one of the following parameters

• - humidity in the storage compartment,
• - Duration of the drying process,
• - weight of the material,
• - Duration of a heating, cooling or defrosting phase of the heat exchanger, has reached a limit.

This limit value can be determined based on an initial value of at least one of said parameters and / or the type of material.

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

• 1 einen schematischen Schnitt durch ein erfindungsgemäßes Kältegerät;
• 2 einen Kältemittelkreislauf des Kältegeräts; und
• 3 ein Flussdiagramm eines von einer Steuereinheit des Kältegeräts ausgeführten Betriebsverfahrens.

Show it

• 1 a schematic section through an inventive refrigerator;
• 2 a refrigerant circuit of the refrigeration device; and
• 3 a flowchart of a running of a control unit of the refrigerator operating method.

1 shows in a schematic section a part of a housing 1 a refrigeration device. In addition to a fully shown chamber 2 can one or more, in the figure only fragmentary shown chambers 3 to be available. The chamber 2 is through an intermediate wall 4 in a heat exchanger chamber 5 and a storage compartment 6 divided. The heat exchanger chamber 5 contains in a conventional manner as an evaporator for cooling the storage compartment 6 operable heat exchanger 7 and a fan 8th to drive a stream of air 9 passing through the heat exchanger chamber 5 and the storage compartment 6 circulated. The storage compartment 6 is with too dehydrating material 11 feedable

At the heat exchanger 7 can be mounted a known per se, electrically operated defrost heater. Preferably, however, is instead the heat exchanger 7 itself either as an evaporator or as heat to the heat exchanger chamber 5 dispensing liquefier operable, as will be explained later in more detail.

At the bottom of the heat exchanger chamber 5 , under the heat exchanger 7 , extends a gutter 16 for condensate draining from the heat exchanger. A condensation drain 17 leads from the lowest point of the gutter 16 through a the chamber 2 surrounding insulation layer to an evaporation tray 18 , The evaporation tray 18 can be in a machine room of the refrigerator tightly adjacent to a compressor 19 be arranged to be heated by its waste heat.

An electronic control unit 10 is with one on the heat exchanger 7 mounted heat exchanger temperature sensor 12 and with a storage compartment temperature sensor 13 on a wall of the storage compartment 6 connected.

Optionally, the control unit 10 with a hygrometer 14 be connected, on the way of the air flow 9 , preferably at an inlet of the heat exchanger chamber 5 , is arranged.

Furthermore optional can in the storage compartment 6 a balance 15 be provided with the material to be dehydrated 11 can be loaded to give readings of its weight to the control unit 10 to deliver. At the scale 15 it may be a household scale, which is autonomously operable outside the refrigerator and only for drying the material 11 in the storage compartment 6 placed and with the control unit 10 is connected.

2 shows a refrigerant circuit according to a preferred embodiment of the refrigerator. At one of a pressure port of the compressor 19 outgoing refrigerant line 20 is initially an outside on the body 1 exposed liquefier 21 connected. Behind the condenser forks the line 20 in two branches 22 . 23 , On the branch 22 are a first controllable throttle 24 , the heat exchanger 7 and a second controllable throttle 25 connected in series, on the branch 23 a third controllable throttle 26 , a heat exchanger 27 one of the chambers 3 and a fourth controllable throttle 28 , From a junction of the two branches 22 . 23 the line runs 20 via an evaporator 29 another subject 3 to a suction port of the compressor 19 , The throttle points 24 . 25 . 26 . 28 can be expansion valves. Their flow conductance is through the control unit 10 adjustable.

When with the compressor running 19 the Strömungsleitwert the throttle point 24 low, that of the throttle 25 on the other hand, the pressure drop is predominantly at the throttle point 24 instead, and the pressure in the heat exchanger 7 is low enough to reach a vaporization temperature below 0 ° C. If, however, the throttle point 24 wide open and the throttle point 25 is tight, the pressures in the condenser 21 and in the heat exchanger 7 essentially the same. As the heat exchanger 7 cooler than the condenser 21 Essentially, condensation takes place in the heat exchanger 7 instead, and the heat released by this is from the air flow 9 in the storage compartment 6 transfer. This heat becomes the subject 3 of the evaporator 29 withdrawn, because there the refrigerant evaporates again.

3 shows an operating method of the control unit 10 , A drying process begins with a user issuing a corresponding command at a user interface 30 enters (S1). The control unit 10 initiates a cooling phase S2 by the throttle point 24 on low, the throttle point 25 switches to high conductance and the compressor 19 and the fan 8th operates. The heat exchanger 7 Cools down to a temperature below 0 ° C, and cold air from the heat exchanger 7 reaches the storage compartment 6 , Meanwhile, warm air sucked out of the storage compartment loads its moisture as a frost on the heat exchanger 7 from. This condition is maintained until the storage compartment temperature sensor 13 indicates that a lower limit temperature Tmin has fallen below. To freeze the material 11 in the storage compartment 6 To avoid this, the lower limit temperature Tmin should be selected above 0 ° C.

If the switch-off threshold temperature is exceeded, a check can be made in step S3 as to whether conditions for terminating the drying process have been met. These may vary depending on which sensors the refrigerator is equipped with and will be described later.

If these conditions are not met, the throttle will be 24 on high and the throttle point 25 switched to low conductance. The compressor 19 stays in operation so that the refrigerant is in the heat exchanger 7 condenses instead of evaporating. The ventilator 8th can remain in operation while: Preferably, however, it is first turned off to the heat exchanger in a defrost phase S4 7 warm as long as the heat exchanger temperature sensor 12 a positive temperature of the heat exchanger 7 displays. If this is the case, the frost is from the heat exchanger 7 defrosted, and the water is over the condensate drain 17 drained. In the following heating phase, the fan blows 8th warm air from the heat exchanger 7 into the storage compartment 6 , The storage compartment 6 and the material 11 it warms up until an upper limit temperature Tmax is exceeded. This upper limit temperature Tmax may be at the user interface 30 be adjustable or from the control unit 10 based on at the user interface 30 information given on the nature of the material 11 be determined; In order to achieve a fast drying, an upper limit temperature Tmax should be adjustable above the room temperature, preferably above 40 or even 50 ° C.

In the case of 3 If the upper limit temperature Tmax is exceeded, the method returns immediately to step S2. Alternatively, at this point it could be checked whether the conditions for the completion of the drying process are met.

In the simplest case, if the hygrometer 14 is present, the termination condition may be below an air humidity limit. Such a limit may vary depending on the nature of the material to be dehydrated 11 be predetermined differently and stored in a memory, the control unit 10 based on information provided by the user about the material 11 queries.

As a further condition, it may be provided to terminate the drying process when the humidity at the end of the cooling or heating phases does not change over several cycles of the process or when the total duration of the drying process has reached a maximum permissible value.

If the balance 15 is present, the control unit can stop the drying process when the weight of the material 11 on one - preferably depending on the type of material 11 predetermined weight fraction at the beginning of the drying process, or when the weight does not change during one cycle of the process.

According to a further development, during a defrost phase S4, the control unit measures the defrost time required for the heat exchanger to heat up from a predetermined temperature just below 0 ° C. to a temperature just above it. This time is a measure of the amount of tire collected in the previous cooling phase. If it is shorter than a given limit, then the material 11 considered dry and the drying process finished.

When setting this limit, the amount of storage in the storage compartment should be 6 charged material 11 be taken into account; the larger this is, the larger the amount of tire that is still on the heat exchanger 7 precipitates when the material has already dried to the required extent. Therefore, according to a second development, the control unit also measures the duration of the cooling phase. This is linearly dependent on the amount of material 11 , Therefore, in particular from the duration of the first cooling phase, the amount of material can be estimated and the limit value of the defrost time can be determined in proportion to this amount of material.

It is also conceivable, from the shortening of the cooling phases in the course of a dehydration on the weight loss of the material 11 close and stop the drying process when this weight loss has reached a predetermined fraction of the initial weight.

The ratio between the estimated amount of material based on the duration of a cooling phase and the estimated amount of water based on the defrosting time of the subsequent heating phase the control unit 10 to recognize if the material 11 , which is in the storage compartment, is easy or difficult to dry. With easy-to-dry, high-surface-area material, the loss of water in each cycle is high, and accordingly, it can also set the defrost limit as it completes the dehydration process. For a material that is difficult to dry, such as fruit protected from dehydration, a much lower limit of defrost time must be selected for the same amount of material to ensure adequate drying.

The refrigeration device can be a network interface 31 , For example, to a wireless network or wireless network, over which the control unit 10 sends a message to a networked device, such as a user's smartphone, to alert the user when the dehydration process is complete and the material 11 from the storage compartment 6 removed and replaced with fresh.

On the networked device can be installed a special app to the message of the control unit 10 to process. The processing may consist in generating instantaneously - preferably acoustic or haptic - a signal that the user can perceive without having to look at the networked device and provide information read by the user on a screen of the networked device can, if indicated by the signal, activate the screen. But it is also possible to register the refrigerator as a participant in a known text messaging service such as SMS or WhatsApp and use this text messaging service to send the message to the networked device.

LIST OF REFERENCE NUMBERS

1

casing

2

chamber

3

chamber

4

partition

5

heat exchanger chamber

6

warehouse specialist

7

heat exchangers

8th

fan

9

airflow

10

control unit

11

material

12

Heat exchanger temperature sensor

13

Storage compartment temperature sensor

14

hygrometer

15

Libra

16

collecting channel

17

condensate drain

18

evaporation tray

19

compressor

20

Refrigerant line

21

condenser

22

branch

23

branch

24

restriction

25

restriction

26

restriction

27

heat exchangers

28

restriction

29

Evaporator

30

User interface

31

Network Interface

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• JP 2008032392 [0004]

Claims (15)

Refrigerating appliance with a storage compartment (6), a heat exchanger chamber (5) separated from the storage compartment (6), which contains a heat exchanger (7) which can be operated as an evaporator and a heater, a fan (8) for driving the air exchange between storage compartment (6) and heat exchanger chamber (5), and a control unit (10) for controlling the operation of the heat exchanger (7), fan (8) and heater, characterized in that the control unit (10) supports a drying mode of operation in which the fan (8) simultaneously with the Heating is in operation. Refrigeration device after Claim 1 , characterized in that in the drying mode of operation heating phases (S5), in which the fan (8) is simultaneously in operation with the heating, alternate with cooling phases (S2), in which simultaneously the heat exchanger (7) as evaporator and the fan ( 8) are in operation. Refrigeration device after Claim 2 , characterized in that the control unit (10) is adapted to insert between a cooling phase (S2) and a subsequent heating phase (S5) a defrosting phase (S4) in which the heater without the fan (8) is in operation. Refrigeration device after Claim 3 characterized in that the control unit (10) is connected to a heat exchanger temperature sensor (12) and is adapted to transition from the defrosting phase (S4) to the heating phase (S5) when the temperature of the heat exchanger (7) changes from negative to low positive value has risen. Refrigeration device after Claim 3 or 4 , characterized in that the control unit (10) is arranged to detect the duration of the defrosting phase (S4) and to end the dehydration mode (S3) if this duration falls below a threshold value. Refrigerating appliance according to one of the preceding claims, characterized in that the control unit (10) with a storage compartment temperature sensor (13) is connected and adapted to detect the rate of change of the temperature of the storage compartment (6). Refrigerating appliance according to one of the preceding claims, characterized in that the control unit (10) with a user interface (30) is connected and adapted to receive from this an input of a user on the nature of the in the storage compartment (6) loaded material (11) , Refrigerating appliance according to one of the preceding claims, characterized in that the control unit (10) is connected to a balance (15) which is arranged in the storage compartment (6) in order to weigh the material (11) loaded into the storage compartment (6), and the control unit (10) is arranged to decide on the basis of the weight of the material (11) about a termination of the drying operation mode (S3). Refrigerating appliance according to one of the preceding claims, characterized in that the heat exchanger (7) is switchable between operation as an evaporator and operation as heating. Refrigerating appliance according to one of the preceding claims, characterized in that the heat exchanger (7) in a refrigerant circuit with at least one throttle point (24, 25) is connected in series, whose passage rate is controlled by the control unit (10). Refrigerating appliance according to one of the preceding claims, characterized in that the control unit (10) is adapted to send a message about the termination of the operating mode to a networked device. Method for dehydrating material (11) in a refrigeration appliance with the steps a) introducing the material (11) into a storage compartment (6) of the refrigeration device; and b) circulating air (9) between the storage compartment (6) and a heat exchanger chamber (5) in which the air is heated alternately in a heating phase (S5) and cooled in a cooling phase (S2) by a heat exchanger operated as an evaporator (7) becomes. Method for dehydrating material (11) in a refrigeration appliance with the steps a) introducing the material (11) into a heatable by a heat exchanger (7) storage compartment (6) of the refrigerator; b) Alternate operation of the heat exchanger (7) as an evaporator (S2) and as a condenser (S4, S5). Method according to Claim 12 or 13 characterized in that dehydration is terminated (S3) when at least one parameter selected from - humidity in the storage compartment, - duration of the drying process, - weight of the material, - duration of a heating, cooling or defrosting phase of the heat exchanger is selected, has reached a limit. Method according to Claim 14 , characterized in that the limit value is determined based on an initial value of at least one of the parameters and / or the type of material.

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