DE102019216582A1 - Refrigeration device with a compartment that can be heated and cooled - Google Patents

Abstract

A refrigeration device, in particular a household refrigeration device, has at least a first, a second and a third storage chamber (2, 3, 4), a refrigerant circuit on which the following are connected in series between a pressure connection and a suction connection of a compressor (14): a condenser ( 15), a first expansion valve (17), a first heat exchanger (5) of the first storage chamber (2), a second expansion valve (18), and a second heat exchanger (6) of the second storage chamber (3), one of the third storage chamber (4) associated third heat exchanger (7) and a control circuit (13) for controlling the operation of the compressor (14) and the expansion valves (17, 18). The third heat exchanger (7) is connected in series to the second heat exchanger (6). The control circuit (13) is set up to maintain a higher storage temperature (T4s) in the third storage chamber (4) than in the second storage chamber (3).

Description

The present invention relates to a refrigeration device, in particular a household refrigeration device, with at least one storage compartment that can be optionally heated or cooled.

Such a refrigeration device is off, for example DE 10 2016 032 986 A known. In this known refrigeration device, heat exchangers of the heatable and coolable compartment and a first cooled compartment, each with an upstream and a downstream expansion valve, are arranged in parallel line strands of the refrigerant circuit, and both strands open onto the evaporator of a second cooled compartment. Since the pressure in the latter evaporator is lower than in each of the heat exchangers, the second refrigerated compartment is inevitably the coldest, ie the first refrigerated compartment comes into consideration as a normal refrigerator compartment, the second as a freezer compartment. In order to implement three different temperature zones in the refrigeration device, four expansion valves are therefore required, which makes the known refrigeration device relatively expensive. In addition, its refrigerant circuit is sensitive to overflowing the heat exchangers, which makes a sensitive and correspondingly complex control necessary.

One object of the present invention is therefore to create a refrigeration device with a storage compartment that can be heated and cooled, which is more simply constructed and can accordingly be implemented cost-effectively. Another object is to create an operating method for such a refrigeration device.

• ein Verflüssiger,
• ein erstes Expansionsventil,
• ein erster Wärmeübertrager der ersten Lagerkammer,
• ein zweites Expansionsventil, und
• ein zweiter Wärmeübertrager der zweiten Lagerkammer;

einem der dritten Lagerkammer zugeordneten dritten Wärmeübertrager und einer Steuerschaltung zum Steuern des Betriebs des Verdichters und der Expansionsventile die Steuerschaltung eingerichtet ist, um in der dritten Lagerkammer eine höhere Lagertemperatur aufrecht zu erhalten als in der zweiten Lagerkammer.The object is achieved, on the one hand, in that in a refrigeration device, in particular a household refrigeration device, with at least a first, a second and a third storage chamber, a refrigerant circuit, on which the following are connected in series between a pressure connection and a suction connection of a compressor:

• a liquefier,
• a first expansion valve,
• a first heat exchanger of the first storage chamber,
• a second expansion valve, and
• a second heat exchanger of the second storage chamber;

a third heat exchanger associated with the third storage chamber and a control circuit for controlling the operation of the compressor and the expansion valves, the control circuit is set up to maintain a higher storage temperature in the third storage chamber than in the second storage chamber.

In this design, two expansion valves are still required to set the mass flow through the first heat exchanger and the pressures in the first and second heat exchangers, but the temperature of the third storage chamber can be controlled without resorting to expansion valves by using only refrigerant vapor or steam and, as required liquid refrigerant can be let through in variable proportions from the second to the third heat exchanger. An overflow of the second heat exchanger does not lead to malfunctions here and does not have to be suppressed by control technology, but is part of normal operation of the refrigeration device in that it enables the third heat exchanger to be supplied with liquid refrigerant.

The connection between the second and third heat exchanger does not require any further expansion valve; on the contrary, this connection should be as free as possible of throttling points which impede the passage of refrigerant to the third heat exchanger or which promote a pressure difference between the second and third heat exchanger. The smallest free cross section of a refrigerant line connecting the heat exchangers is preferably essentially the same size, but in any case at least half as large as a mean free cross section of lines of the heat exchangers.

The speed of the compressor should be adjustable to a large number of values, preferably continuously, so that fluctuations in the temperature in the storage chambers over time and the additional consumption of electrical energy associated with these fluctuations can be minimized by uninterrupted operation of the compressor.

The control circuit is preferably set up to increase the speed of the compressor if the temperature of the second storage chamber is above a setpoint value and / or to reduce the speed of rotation if the temperature of the second storage chamber is below a setpoint value. By increasing the compressor speed, the pressure in a suction line leading to the compressor and via this also the pressure in the second and third heat exchangers can be reduced. Since the cooling effect of the third heat exchanger is largely not based on the evaporation of liquid refrigerant in it, but rather on the vapor flowing through it originating from the second heat exchanger, the change in speed influences the cooling effect of the third heat exchanger at most slightly; On the other hand, the pressure decrease has a direct effect on the evaporation of the refrigerant taking place in the second heat exchanger.

The above mentioned setpoints can be identical; but they can also push the limits of a Define the interval within which the speed of the evaporator remains unchanged.

In order to regulate the temperature in the third storage chamber, the control circuit is preferably set up to increase the degree of opening of the first expansion valve when the temperature of the third storage chamber is above a target value, and / or to decrease the degree of opening of the first expansion valve when the temperature of the third storage chamber is below a target value. Although the first expansion valve and the third heat exchanger in the refrigerant circuit are separated in one direction by two heat exchangers and the second expansion valve and in the other by the compressor, an adjustment of the first expansion valve surprisingly affects the third heat exchanger in particular. Opening the first expansion valve initially causes a reduction in the throttling effect of the entire refrigerant circuit. The pressure in the second and third heat exchanger changes only slightly as a result, because as this pressure increases, the throughput of the compressor also increases while the speed remains the same. As a result, the main consequence of opening the first expansion valve is an increased flow of liquid refrigerant through the second expansion valve and consequently, at the latest after the second heat exchanger is completely filled with liquid refrigerant, an increased supply of liquid refrigerant to the third heat exchanger and thus increased cooling the third storage room.

The control circuit can also be configured to increase the degree of opening of the second expansion valve when the temperature of the third storage chamber is above a setpoint value and / or to reduce the degree of opening of the second expansion valve when the temperature of the third storage chamber is below a setpoint value.

A decision as to which of these two options is to be used is expediently made on the basis of a comparison of the setpoint temperature of the first storage chamber with the ambient temperature.

In order to control the temperature of the first storage chamber, the control circuit can be configured to increase the degree of opening of the second expansion valve when the temperature of the first storage chamber is above a target value, and / or to decrease the degree of opening of the second expansion valve when the temperature of the first Storage chamber is below a target value.

Alternatively, the control circuit can be configured to increase the degree of opening of the first expansion valve when the temperature of the first storage chamber is below a setpoint value and / or to reduce the degree of opening of the first expansion valve when the temperature of the first storage chamber is above a setpoint value.

Here, too, the choice between the alternatives can be made by comparing the setpoint temperature of the first storage chamber with the ambient temperature.

A third expansion valve, a fourth heat exchanger of a fourth storage chamber and a fourth expansion valve can be connected to one another in series and connected in parallel to the first expansion valve, the first heat exchanger and the second expansion valve. In this way, several compartments that can optionally be heated or cooled can be created in the refrigeration device.

The temperatures in these compartments can be set independently of one another by setting the evaporation pressures using the upstream and downstream expansion valves.

In a refrigeration device with a fourth storage chamber as described above, the degree of opening of the third expansion valve can also be increased if the temperature of the third storage chamber is above a setpoint value, and / or the degree of opening of the third expansion valve can be reduced if the temperature of the third storage chamber is below a setpoint value lies.

If desired, further storage chambers can be provided, each with an assigned heat exchanger and the expansion valves connected upstream and downstream of this in a branch of the refrigerant circuit.

A fan for driving the exchange of air between the heat exchanger and the storage chamber can be assigned to at least one of the heat exchangers. Such a fan is advantageous in order to intensify the heat exchange with the storage chamber and thus to achieve a high exchange rate with a compact heat exchanger. They are not absolutely necessary to control the cooling of the various storage chambers. In the simplest case, such a fan can therefore be operated at an unregulated or fixed speed.

In particular if a storage chamber is operated in a cooled manner, it can be useful to regulate the speed of the fan based on a predetermined temperature difference between the evaporator and the storage chamber in order to reduce the extent to which the air in the storage chamber is dried by condensation on the evaporator or the Adjust the moisture content of the air.

• Vergrößern des Öffnungsgrads des zweiten Expansionsventils, wenn die Temperatur der ersten Lagerkammer über einem Sollwert liegt, und/oder Verkleinern des Öffnungsgrads des zweiten Expansionsventils, wenn die Temperatur der ersten Lagerkammer unter einem Sollwert liegt.
  • - Erhöhen der Drehzahl des Verdichters, wenn die Temperatur der zweiten Lagerkammer über einem Sollwert liegt und/oder Senken der Drehzahl, wenn die Temperatur der zweiten Lagerkammer unter einem Sollwert liegt;
  • - Öffnen des ersten Expansionsventils, wenn die Temperatur der dritten Lagerkammer über einem Sollwert liegt, und/oder Verkleinern des Öffnungsgrads des ersten Expansionsventils, wenn die Temperatur der dritten Lagerkammer unter einem Sollwert liegt,

sowie durch ein Computerprogrammprodukt, welches Instruktionen umfasst, die bei Ausführung auf einem Computer diesen befähigen, als Steuerschaltung in einem Kältegerät wie oben beschrieben zu arbeiten oder das oben genannte Verfahren auszuführen.The object is also achieved by a method for operating a refrigeration device as described above with the steps:

• Increasing the degree of opening of the second expansion valve when the temperature of the first storage chamber is above a target value, and / or reducing the degree of opening of the second expansion valve when the temperature of the first storage chamber is below a target value.
  • Increasing the speed of the compressor if the temperature of the second storage chamber is above a setpoint value and / or lowering the speed if the temperature of the second storage chamber is below a setpoint value;
  • Opening the first expansion valve when the temperature of the third storage chamber is above a setpoint value and / or reducing the degree of opening of the first expansion valve when the temperature of the third storage chamber is below a setpoint value,

as well as by a computer program product which comprises instructions which, when executed on a computer, enable it to work as a control circuit in a refrigeration device as described above or to carry out the above-mentioned method.

• 1 ein Blockdiagramm eines erfindungsgemäßen Kältegeräts; und
• 2 ein Flussdiagramm eines Betriebsverfahrens des Kältegeräts.

Further features and advantages of the invention emerge from the description of exemplary embodiments with reference to the accompanying figures. Show it:

• 1 a block diagram of a refrigeration device according to the invention; and
• 2 a flow chart of an operating method of the refrigeration device.

1 shows a block diagram of a refrigeration device according to the invention. In a heat-insulating housing 1 are at least three storage chambers 2 , 3 , 4th left out. Each of these storage chambers 2 , 3 , 4th is a heat exchanger 5 , 6th , 7th assigned. The assignment can consist, for example, in that the heat exchanger is embedded in the manner of a cold wall evaporator between an inner container of the storage chamber and an insulating material layer surrounding the inner container, or that the heat exchanger 5 , 6th , 7th in the inner container 8th the relevant storage room 2 , 3 , 4th is mounted. In the latter case, a partition wall can be used in the inner container 9 be provided that the volume of the inner container in the storage chamber 2 , 3 , 4th and one the heat exchanger 5 , 6th , 7th receiving heat exchanger chamber 10 divided. Regardless of how the heat exchanger 5 , 6th , 7th the storage room 2 , 3 , 4th can be assigned to any heat exchanger 5 , 6th , 7th a fan 11 be assigned to the heat transfer between the storage chamber 2 , 3 , 4th and its heat exchanger 5 , 6th , 7th to intensify. The speed or power of such a fan 11 can be fixed or, as will be explained in more detail below, controllable.

Every storage room 2 , 3 , 4th is with a temperature sensor 12th fitted. Measured values of the temperature sensors 12th are controlled by a control circuit 13th detected.

A refrigerant circuit comprises, starting from a pressure connection of a compressor 14th one condenser in turn 15th , a pressure line 16 , a first expansion valve 17th , the heat exchanger 5 , a second expansion valve 18th , the second heat exchanger 6th , the third heat exchanger 7th and a suction line 19th leading to a suction port of the compressor 14th leads. The expansion valves 17th , 18th are of a design known per se, not described here, and designed to maintain a pressure difference between inlet and outlet that is predetermined by a control signal. The source of the control signals is the control circuit 13th . The pressure line 16 and the suction line 19th run in opposite directions along part of their length in close contact with one another, thus creating an internal heat exchanger 22nd to form in which the compressed refrigerant just before reaching the expansion valve 17th Residual heat to the steam in the suction line 19th gives.

The one on the expansion valve 17th adjustable pressure difference is variable within wide limits. On the one hand, the expansion valve allows 17th , in the heat exchanger 5 set a pressure which, if at all, differs only slightly from the pressure at the pressure connection of the compressor 14th differs so that in the heat exchanger 5 like in the condenser 15th Condensation of refrigerant takes place and the storage chamber 2 can be operated at a setpoint temperature above the ambient temperature, and in condenser 15th and heat exchangers 5 condensed refrigerant through the expansion valve 18th the heat exchangers 6th and 7th is fed. An upper limit on the temperature at which the storage chamber 2 can be operated, should not be below + 18 ° C.

There are less stringent requirements for the expansion valve 18th : to an operation of the storage room 3 as a freezer to enable even if the storage chamber 2 is operated as a normal refrigerator compartment, a non-negligible pressure drop at the expansion valve 18th necessary. The maximum pressure difference across the expansion valve 18th should be enough to freeze the storage room 3 even if the compressor is essentially at full output pressure 14th at the inlet of the expansion valve 18th is applied.

Between the heat exchangers 6th and 7th there is no significant drop in pressure. In particular, both heat exchangers 6th , 7th and a conduit connecting them can be made of the same type of pipe with constant cross-sectional dimensions.

Target temperatures for all three storage chambers 2 , 3 , 4th are at a user interface 20th the control circuit 13th adjustable. If one of the storage chambers 2 , 3 , 4th a fan 11 can at the user interface 20th it is also possible to choose a humidity value for the storage chamber in question.

2 Fig. 13 shows a flowchart of an operation method of the control circuit 13th . In step S1, the sensor is used 12th the temperatures T2, T3. T4 in the storage rooms 2 , 3 , 4th measured. In step S2 the user for the storage chamber 2 adjusted setpoint temperature T2s compared with the ambient temperature T _env . The former is lower, that is, if the storage chamber 2 is cooled, the process goes to step S3.

In step S3, the temperature T2 is compared with the target temperature T2s. If both values T2, T2s agree within a predetermined tolerance interval, the method goes directly to step S4. If the measured temperature T2 is significantly lower than T2s, then the control circuit reduces the degree of opening of the expansion valve 18th (S5) in order to determine the pressure or the boiling temperature of the refrigerant in the heat exchanger in this way 5 to raise. The reduction in the degree of opening can result in an increase in that of the expansion valve 18th pressure difference to be maintained between the heat exchangers 5 and 6th consist. Conversely, in step S6 the degree of opening is increased (or the pressure difference is reduced) if the temperature T2 is significantly higher than T2s.

The extent to which the pressure difference is changed in step S5 or S6 can be a constant, or it can take into account circumstances such as the amount of the difference between T2 and T2s or the period of time that the deviation between T2 and T2s already lasts, in order to minimize the time until correspondence between T2 and T2s is restored or control overshoots.

In step S4, the temperature T3 becomes that of the user for the storage chamber 3 set target temperature T3s compared. The heat exchanger 6th the storage room 3 always works as an evaporator; to do this, it is continuously supplied with liquid refrigerant during operation, either in the condenser 15th condensed and in the heat exchanger 5 only a small part has evaporated, or because in the heat exchanger 5 condensation has taken place in addition to that of the condenser. The heat exchanger 6th is, therefore, as in it as in the heat exchanger 7th essentially the suction pressure of the compressor 14th prevails and it is well supplied with liquid refrigerant, the coldest of the heat exchangers 5 , 6th , 7th , and T3, T3s are normally in a range below -10 ° C, for example around -18 ° C, which is typical for a freezer compartment.

If both values T3, T3s match within a predetermined tolerance interval, the method goes directly to step S7. If the measured temperature T3 is significantly lower than T3s, then the control circuit reduces 13th the speed of the compressor 14th (S8) to determine the pressure or the boiling temperature of the refrigerant in the heat exchanger in this way 6th to raise. Conversely, the speed is increased in step S9 if the temperature T3 is significantly higher than T3s.

The extent to which the speed is changed in step S8 or S9 can be a constant, or it can take into account circumstances such as the amount of the difference between T3 and T3s or the time span that the deviation between T3 and T3s has already lasted, in order to minimize the time until correspondence between T3 and T3s is restored or control overshoots.

In step S7, the temperature T4 becomes that of the user for the storage chamber 4th set target temperature T4s compared. If the two values T4, T4s match within a predetermined tolerance interval, the method goes back to step S1 after a predetermined waiting time (S12). If the measured temperature T4 is significantly lower than T4s, then the control circuit reduces the degree of opening of the expansion valve 17th (S10) in order to reduce the mass flow of the refrigerant in this way and thus to reduce the amount of liquid refrigerant that reaches the heat exchanger 7th got. Conversely, the degree of opening is increased in step S11 if the temperature T4 is significantly higher than T4s, so that more liquid refrigerant enters the heat exchanger 7th got.

If, on the other hand, it is determined in step S2 that for the storage chamber 2 Heating mode is selected, ie if T2s> T _env , then T2 is then also compared with T2s (S3`), but if T2 is significantly below T2s, the expansion valve is opened 17th further open (S5 '), or if T2 is significantly above T2s, further closed (S6').

Steps S4, S8, S9 for temperature control in the storage chamber 3 are with the above for the case of cooling operation in the storage chamber 2 described identical.

The regulation of the temperature T4 in the storage chamber 4th then takes place via the expansion valve 18th : If it is determined in step S7 'that it is lower than the target temperature T4s, then the degree of opening of the expansion valve 18th reduced to the supply of liquid refrigerant in the heat exchanger 7th to decrease (S10 '), in the opposite case (S11') the degree of opening is increased.

If desired, a fan can be used 21 on the condenser 15th be arranged to ambient air through the condenser 15th to blow and so the heat dissipation through the condenser 15th to accelerate. The fan 21 can run at a fixed speed. It is also conceivable that the control circuit 13th its speed in the same direction as that of the compressor 14th or varies with the ambient temperature in order to cope with the increased heat build-up on the condenser with increased compressor output 15th To take into account.

The speeds of the fans 11 are of the temperatures in the storage chambers 2 , 3 , 4th and the environment independent. They can be fixed; especially in the case of the storage chamber that can be used as a normal refrigerator compartment 4th it may be useful to the user at the interface 20th the choice between different performance levels or speeds of the fan there 11 to give. The higher the performance of the fan 11 , the smaller the temperature difference between the storage chamber 4th and evaporator 7th which is sufficient to reach the set temperature T4s of the storage chamber 4th to maintain. And the higher the temperature of the heat exchanger 7th is, the smaller the proportion of humidity from the storage chamber 4th , the one on the heat exchanger 7th condensed and directed to the open air. A high fan output is therefore suitable for storing items that are sensitive to drying out. A lower fan output can be set for items to be cooled that tend to form mold or the like in high humidity.

The same considerations apply to controlling the fan 11 in the storage room 2 if this is used as a normal cooling compartment or in an adjacent temperature range, e.g. as a fresh cooling compartment.

In order to be able to create ideal storage conditions for both items that are sensitive to dehydration and items that are sensitive to moisture, it may be desirable to have more than the three in the 1 to have shown storage chambers in a refrigeration device. For cooling or heating such a further storage chamber, the refrigerant circuit can have a plurality of line strands, each of which extends between connection points 23 the pressure pipe 16 and 24 one the expansion valve 18th with the heat exchanger 6th connecting pipe extend, each of which, analogous to the components 17th , 5 , 18th has in series an upstream expansion valve, a heat exchanger for the further storage chamber and a downstream expansion valve.

List of reference symbols

1

casing

2

Storage room

3

Storage room

4th

Storage room

5

Heat exchanger

6th

Heat exchanger

7th

Heat exchanger

8th

Inner container

9

partition wall

10

Heat exchanger chamber

11

Fan

12th

Temperature sensor

13th

Control circuit

14th

compressor

15th

Condenser

16

Pressure line

17th

Expansion valve

18th

Expansion valve

19th

Suction line

20th

User interface

21

Fan

22nd

internal heat exchanger

23

Connection point

24

Connection point

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed 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

• DE 102016032986 A [0002]

Claims (13)

Refrigeration device, in particular household refrigeration device, with at least a first, a second and a third storage chamber (2, 3, 4), a refrigerant circuit on which the following are connected in series between a pressure connection and a suction connection of a compressor (14): a condenser (15 ), a first expansion valve (17), a first heat exchanger (5) of the first storage chamber (2), a second expansion valve (18), and a second heat exchanger (6) of the second storage chamber (3), one of the third storage chamber (4) associated third heat exchanger (7) and a control circuit (13) for controlling the operation of the compressor (14) and the expansion valves (17, 18), characterized in that the third heat exchanger (7) is connected in series to the second heat exchanger (6) and that the control circuit (13) is set up to maintain a higher storage temperature (T4s) in the third storage chamber (4) than in the second storage chamber (3). Appliance after Claim 1 , characterized in that the second and the third heat exchanger (6, 7) are connected to one another without an interposed throttle point. Appliance after Claim 1 or 2 , characterized in that the speed of the compressor (14) can be set to a large number of values, preferably continuously, and the control circuit (13) is set up to increase the speed when the temperature (T3) of the second storage chamber is above a setpoint value ( T3s) and / or to reduce the speed when the temperature (T3) of the second bearing chamber is below a setpoint (T3s). Refrigerating device according to one of the preceding claims, characterized in that the control circuit (13) is set up to increase the degree of opening of the first expansion valve (17) when the temperature (T4) of the third storage chamber (4) is above a setpoint value (T4s), and / or to reduce the degree of opening of the first expansion valve (17) when the temperature (T4) of the third storage chamber (4) is below a setpoint value (T4s). Refrigerating device according to one of the preceding claims, characterized in that the control circuit (13) is set up to increase the degree of opening of the second expansion valve (18) when the temperature (T4) of the third storage chamber (4) is above a setpoint value (T4s), and / or to reduce the degree of opening of the second expansion valve (18) when the temperature (T4) of the third storage chamber (4) is below a setpoint value (T4s). Refrigerating device according to one of the preceding claims, characterized in that the control circuit (13) is set up to increase the degree of opening of the second expansion valve (18) when the temperature of the first storage chamber (2) is above a setpoint value (T2s), and / or to reduce the degree of opening of the second expansion valve (18) when the temperature (T2) of the first storage chamber (2) is below a target value (T2s). Refrigerating device according to one of the preceding claims, characterized in that the control circuit (13) is set up to increase the degree of opening of the first expansion valve (17) when the temperature of the first storage chamber (2) is below a setpoint value (T2s), and / or to reduce the degree of opening of the first expansion valve (17) when the temperature (T2) of the first storage chamber (2) is above a target value (T2s). Refrigerating device according to one of the preceding claims, characterized in that the control circuit (13) is set up to select an expansion valve to be adjusted depending on whether the temperature (T4) of the third storage chamber (4) deviates from a target value (T4s) depending on whether a target temperature (T2s) of the first storage chamber (2) is above or below an ambient temperature (T _env ). Refrigeration device according to one of the preceding claims, characterized in that a third expansion valve, a fourth heat exchanger of a fourth storage chamber, and a fourth expansion valve are connected to one another in series and to the first expansion valve (17), the first heat exchanger (5) and the second expansion valve (18 ) are connected in parallel. Refrigerating device according to one of the preceding claims, characterized in that at least one of the heat exchangers (5, 6, 7) has a fan (11) for driving the exchange of air between the heat exchanger (5, 6, 7) and the storage chamber (2, 3, 4 ) assigned. Appliance after Claim 10 , characterized in that the control circuit (13) is set up to regulate the speed of at least one fan (11) based on a predetermined temperature difference between the evaporator (5, 6, 7) and the associated storage chamber (2, 3, 4). Method for operating a refrigeration device according to Claim 1 with the steps: increasing (S6) the degree of opening of the second expansion valve (18), if (S3) the temperature (T2) of the first storage chamber (2) is above a target value (T2s), and / or reducing (S5) the degree of opening of the second expansion valve (18) when the Temperature of the first storage chamber (2) is below a target value (T2s). - Increase (S9) the speed of the compressor (14) when (S4) the temperature (T3) of the second storage chamber (3) is above a setpoint value (T3s) and / or decrease (S8) the speed when the temperature (T3 ) the second storage chamber (3) is below a target value (T3s); - Increase (S11) the degree of opening of the first expansion valve (17) when the temperature (T4) of the third storage chamber (4) is above a target value (T4s), and / or decrease (S10) the degree of opening of the first expansion valve (17), when the temperature (T4) of the third storage chamber (4) is below a target value (T4s). Computer program product which comprises instructions which, when executed on a computer, enable it to act as a control circuit in a refrigeration device according to one of the Claims 1 to 11 to work or follow the procedure Claim 12 to execute.

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