CH715229A1 - Cooling device with multiple temperature zones. - Google Patents

Abstract

A first evaporator (40) is provided in a cooling air duct in a cooling device. With a fan, air is conveyed through the cooling air duct from top to bottom. It returns at different heights in two temperature zones (2a, 2b) of the useful space (2) of the cooling device. The cooling medium is conveyed from bottom to top through the evaporator (40). The temperature in the two temperature zones (2a, 2b) can be regulated to different target temperatures by suitable control of the delivery rate of the fan as well as the upper limit (68a, 68b) and evaporation temperature of the liquid cooling medium in the evaporator (40).

Description

Description Field of the Invention The invention relates to a cooling device with several temperature zones and a method for its operation according to the preamble of the main claims.

Background US 2009/0 188 262 describes a cooling device whose cooling space is divided into several temperature zones with different target temperatures. A cooling air duct is provided, in which air is drawn in from the uppermost temperature zone. The air is guided along the evaporator and led back into the temperature zones via several connection openings. Air flaps are provided at the connection openings, which are individually controlled. The temperature in the temperature zones is regulated by suitable control of these air flaps.

DESCRIPTION OF THE INVENTION It is the object of a cooling device of this type or » to provide a method for its control with improved temperature control.

This object is solved by the subject matter of the independent claims.

[0005] Accordingly, the cooling device comprises at least the following elements:

- A usable space: This is used to store the refrigerated goods. In particular, this can be food. However, other objects can also be cooled, e.g. Medicines, medical samples, chemicals, etc.

- A heat pump: This comprises, in a manner known per se, at least a first evaporator, a condenser and a compressor. The compressor conveys a cooling medium through the condenser and the first evaporator. The first evaporator can be the only evaporator, or at least one second evaporator can also be provided.

- A cooling air duct: The cooling air duct is connected to the usable space via at least one suction opening and several blow-back openings. The blow-back openings are arranged along the cooling section at different, vertically spaced positions.

- A fan: The fan serves to convey air in the cooling air duct from the intake opening to the blow-back openings. As a result, air is conveyed from the refrigerator to the first evaporator and back again, in order to cool the refrigerator.

- A controller: The controller is designed to maintain different target temperatures in the different temperature zones.

Furthermore, the compressor is designed to convey the cooling medium from bottom to top through the first evaporator. With this flow direction of the cooling medium, there is significantly more liquid cooling medium in a lower region of the first evaporator than in the upper region. Since the liquid cooling medium draws more heat from its surroundings when it evaporates than the medium that has already evaporated, this leads to a relatively strong, vertical temperature gradient in the first evaporator. Accordingly, the air that flows through the various blow-back openings is cooled to different degrees.

The control of the device is designed to control the amount of liquid medium in the first evaporator depending on the target temperatures and the actual temperatures in the temperature zones.

Since the upper limit of the liquid cooling medium in the first evaporator (and thus the area with strong cooling) is dependent on the amount of liquid medium, it is possible in this way to control how strongly the air that flows through the differently arranged blow-back openings , is cooled.

In particular, the controller can be configured to set the upper limit of the liquid cooling medium in the first evaporator depending on the target temperatures and the actual temperatures in the temperature zone above or below at least a first blow-back opening. If this upper limit lies below this first blow-back opening, the air conveyed through this first blow-back opening is cooled less than if the upper limit lies above the first blow-back opening.

Advantageously, at least one second blow-back opening is provided below (i.e. lower than) the first blow-back opening. In this case, depending on the upper limit of the liquid cooling medium, there are strong differences in the cooling capacity between the first and the second blow-back opening, which can be used for individual regulation of the cooling capacity in the region of the two blow-back openings.

A particularly good regulation can be achieved if the control also controls the delivery capacity of the fan depending on the target temperatures and the actual temperatures. By e.g. is selected to be relatively high, the outlet temperature at the blow-back openings can be increased, in particular at the blow-back openings which are lower than the upper limit of the liquid cooling medium.

CH 715 229 A1 [0012] Another good control parameter is the delivery capacity of the compressor. Accordingly, the control can be configured to control the delivery capacity of the compressor depending on the target temperatures and the actual temperatures in the temperature zones.

With the present technique it is possible to control the temperatures at the blowback openings without the closure means controlled at the blowback openings, e.g. Air flaps are arranged. However, the invention can also be used in combination with such controlled closure means in the blow-back openings, in which case the temperatures can be regulated even better and / or with greater efficiency.

Furthermore, at least two throttles can be arranged between the condenser and the first evaporator, and a changeover valve can be provided in order to vary the flow ratio of cooling medium between the two throttles. In other words, the ratio of the flows through the two throttles can be varied with the changeover valve. For example, the changeover valve can either guide the cooling medium through one or the other throttle, or the ratio can also be set variably. In both cases, the control can be configured to control the amount of liquid medium in the first evaporator at least via the changeover valve.

[0015] In one embodiment, in addition to the first evaporator, at least one second evaporator can be provided. The first of the throttles leads cooling medium from the compressor past the second evaporator to the first evaporator. The second of the throttles leads cooling medium from the compressor to the second evaporator. In this case, more or less cooling medium can be passed through the second evaporator via the changeover valve, as a result of which the amount of liquid cooling medium and the evaporation temperature in the first evaporator can be varied. In particular, a higher resulting air temperature can result from overheating of the refrigerant in the first evaporator.

[0016] The invention also relates to a method for operating such a cooling device. The amount of liquid cooling medium in the first evaporator is controlled depending on the target temperatures and the actual temperatures in the temperature zones.

Furthermore, the delivery rate of the compressor and / or the delivery rate of the fan can be controlled depending on the target temperatures and the actual temperatures in the temperature zones.

The cooling device is advantageously a refrigerator and / or a freezer, in particular a household appliance. However, it can also be a refrigerator for other applications, e.g. a cooling device for medication or other refrigerated goods.

BRIEF DESCRIPTION OF THE DRAWINGS Further refinements, advantages and applications of the invention result from the dependent claims and from the description that follows with reference to the figures. It shows:

1 is a view of part of a refrigerator (door not shown),

2 shows a section of the cooling device according to FIG. 1 from the front,

3 is a view of the rear wall element obliquely from the front,

4 shows the rear wall element of FIG. 3 without a cover plate,

5 shows the cover plate of the rear wall element of FIG. 3,

6 the rear wall element of FIG. 3 obliquely from behind,

7 is a sectional view through the rear wall element of FIG. 6,

8 is the sectional view of FIG. 7 from the cut side,

9 is a somewhat simplified detail of FIG. 8,

10 is a somewhat simplified section through the rear wall element and the rear wall of the device,

11 shows a schematic illustration of some of the most relevant components of the cooling device in the present case,

12 is a schematic view of the usable space with the air flows drawn in from the front,

Fig. 13 the usable space of Fig. 12 from the side.

CH 715 229 A1

WAYS OF CARRYING OUT THE INVENTION Definitions:

The terms "rear", "rear", "front", "front" are defined so that the door of the refrigerator is at the front, i.e. is located on the front, while the rear of the device indicates the side of the device opposite the door.

Terms such as "top", "bottom", "horizontal" and "vertical" refer to the intended orientation of the device, in which the door runs vertically.

An «insulation material» is a body with a thermal conductivity of less than 0.1 W / mK, in particular less than 0.05 W / mK. With vacuum insulation panels, the value can even be below 0.01 W / mK, e.g. at 0.003-0.006 W / mK.

Overview:

1 and 2 show a refrigerator as an example of a refrigerator, the door not being shown. The refrigerator has a housing 1, in the interior of which a useful space 2 is arranged for receiving food to be stored. In a section in the vertical direction, the usable space 2 has an approximately rectangular cross section.

On the rear wall 2a of the usable space, a rear wall element 3 is arranged, which is highlighted in FIG. 2 with a bold outline.

The usable space is divided into two temperature zones 2a, 2b in the present embodiment. An intermediate wall 11 is arranged between the two temperature zones 2a, 2b, which e.g. can have the shape of a shelf or drawer lid. The intermediate wall 11 is designed in such a way that it allows an air exchange between the two temperature zones 2a, 2b.

[0026] The intermediate wall can have an insulation material.

Different target temperatures are assigned to the temperature zones 2a, 2b. The target temperatures advantageously increase from bottom to top, i.e. the lowest target temperature is assigned to the lowest temperature zone 2a.

Back panel element:

The rear wall element 3 is shown in Fig. 3-7 from the front and rear and in Fig. 8 in a vertical section.

It has a substantially rectangular outline and has a plate shape. It has a molded body 4 made of an insulating material, e.g. made of expanded polystyrene.

On the front of the molded body 4, a cover plate 5 is attached. It consists of a material of higher strength than the molded body 4. It is preferably made of plastic.

For optimum protection, the cover plate 5 preferably extends on the front over the entire wall element 3 or at least over the entire molded body 4.

The rear wall element 3 preferably has a first section 3a (cf. FIGS. 7, 8) and a second section 3b. The fan 10 is arranged in section 3a. In this section 3a, the rear wall element 3 is thicker in the direction from the front to the rear than in the second section 3b. This takes into account the fact that the two parts 6a, 6b of the cooling air duct overlap in section 3a, while this is not the case in section 3b. With this configuration, the rear wall element 3 takes up less volume.

The exact design of the rear wall element 3 is, however, of secondary importance in the present case. For example, also have a simpler plate shape.

Cooling air duct:

A cooling air duct 6 can be formed in or on the rear wall element 3 (or elsewhere in the device). It is used to guide cooling air past an evaporator. An exemplary structure of the cooling air duct is described in more detail below.

In the illustrated embodiment, a first part 6a of the cooling air duct is configured on the front of the molded body 4, namely between the molded body 4 and the cover plate 5. This first part is best seen in FIGS. 4 and 10.

For example, the cooling air duct has a plurality of intake openings 7a-7i. Of these, e.g. four suction openings 7a-7d on the lateral edges 8a, 8b of the rear wall element 3, in particular in the upper quarter of the lateral edges 8a, 8b, and the rest on the upper edge 8c.

The suction openings 7a-7i form channel sections which are formed between depressions 9a, 9b, 9c ... in the molded body 3 and the cover plate 5 and which lead to a fan 10.

CH 715 229 A1 In the present example, the fan 10 is arranged with an opening 12 extending from the front to the rear through the molded body and is shown in detail in FIG. 9.

The fan 10 shown has a rigid frame 14 in which a fan wheel 15 and its drive are arranged. The frame 14 can be fastened to the molded body 4 via a damping element 16.

The damping element 16 can in turn be attached to the molded body 4 in a suitable manner. For this purpose, as can best be seen in conjunction with FIGS. 6, 7 and 9, a holding frame 18 is provided in the present embodiment. The damping element 16 is clamped between a shoulder 20 of the molded body 4 and the holding frame 18.

The holding frame 18 is inserted in a recess of the molded body 4 and preferably snapped there into undercuts 24, so that it can only be removed with deformation.

Furthermore, the holding frame 18 has protrusions 26 projecting to the rear, which are supported against the front of the rear wall 30, which is located behind the rear wall element 3 and forms a counter bearing 32, when the rear wall element 3 is properly installed.

At the rear of the opening 10, the second part 6b of the cooling air duct connects, cf. 6, 9, 10.

For this purpose, the molded body 4 has on its rear side one or more recesses 34 which form or form the front area of part 6b of the cooling air duct.

As can best be seen from FIG. 6, the recess 34 extends from the area of the fan 10 towards the bottom, to the lower end of the molded body 4.

In one embodiment, the molded body 4 can form at least two lateral boundaries 36 for the recess 34, which touch the rear wall 30 in the assembled state of the wall element 3 and thus laterally limit the cooling air duct.

One or preferably both of these boundaries 36 has or have recessed areas which do not touch the rear wall and which form a plurality of laterally arranged first blow-back openings 38a-38m of the cooling air duct on the side edges 8a, 8b of the rear wall element 3.

The first blow-back openings 38a-38m lead into the first temperature zone 2a.

The rear wall also forms laterally arranged second blow-back openings 38n. These lead to the second temperature zone 2b.

Furthermore, the shaped body 4 shown forms an upper boundary 39a of the recess 34, which contacts the rear wall 30 in the assembled state of the wall element 3. This advantageously closes off the second part 6b of the cooling air duct at the top.

In addition, the shaped body 4 shown forms a lower boundary 39b of the recess 34. In the illustrated embodiment, the lower boundary 39b has one or more recessed areas which do not touch the rear wall 30 and thus one or more lower, second Blow-back openings 43 for the cooling air duct on the lower edge 8d of the rear wall element 3 forms or form.

The lower second blow-back openings 43 also lead into the second temperature zone 2b.

Furthermore, the molded body 4 can form spacers 37 which support the recess 34 against the rear wall. In addition, such spacers 37 can also be used as air guiding elements.

As can best be seen from FIG. 7, the recess 34 is advantageously not the same depth everywhere. In particular, it has an upper, lower region 34a and a lower, less deep region 34b. This configuration allows the air flow in the cooling air duct to be brought into a desired ratio in accordance with the requirements.

As can be seen from FIG. 10, the evaporator 40 of a heat pump is arranged in the rear wall 30 of the cooling device. It is thermally connected to a wall plate 42 which forms the inside of the rear wall 30, i.e. the side facing the usable space 2.

The configuration of the heat pump is described in more detail below. As can be seen from this, the present embodiment of the cooling device has two evaporators, which is why the evaporator 40 is sometimes referred to below as the “first evaporator 40”. The terms "first" and "second" evaporators are only used for enumeration and do not describe the flow sequence of the evaporators. The refrigerant preferably flows first through the second and then through the first evaporator.

Behind the evaporator 40, i.e. to the outside, an insulation element 44, in particular a vacuum insulation panel, is arranged.

The area of the cooling air duct 6a, 6b which is in contact with the evaporator 40 is referred to as the cooling section 13.

The blow-back openings 38a-38n and 43 are arranged along the cooling section 13 at different, vertically spaced apart positions.

CH 715 229 A1 In operation, the fan 10 conveys the air from front to back, i.e. it sucks in the air through the suction openings 7a-7i, conveys it through the first part 6a of the cooling air duct, through the opening 12, through the second part 6b of the cooling air duct and to the blow-back openings 38a-38n and 43.

Examples of corresponding air flows are shown in dashed lines in FIGS. 4 and 6.

The air is cooled by the evaporator 40 as it passes through the second part 6b of the cooling air duct.

In the embodiment shown, the air essentially runs from top to bottom through the cooling air duct and sweeps past the cooling element or evaporator 40 from top to bottom.

In the embodiment shown, the cooling element (i.e. the evaporator 40) is arranged behind the wall plate 42. However, it can also be arranged in the cooling air duct itself and e.g. be surrounded by cooling air on both sides.

The exact design of the evaporator is of secondary importance in the present context. For example, it can be foamed in or arranged freely in the air flow. For example, act as a tube, roll bond or finned heat exchanger.

Since in the present example the air enters and exits at the edges 8a-8d of the rear wall element 3, gaps or distances to the adjacent components of the useful space 2 are to be provided in this area, at least in the area of the intake and blow-back openings.

Cooling mode:

In the following, the cooling operation of the device is described in more detail.

First of all, reference is made to FIG. 11, which shows the most important components of the cooling system of the device.

The cooling device has a heat pump with a compressor 50, a condenser 52, a changeover valve 54, a plurality of throttles 56a, 56b (which in the present case are configured as capillaries), the first evaporator 40 and a second evaporator 58.

[0070] The components of the cooling device are controlled by a controller 60. This can also communicate with sensors that measure the current state of the device, e.g. a first temperature sensor 62a for measuring the temperature in the first temperature zone 2a and a second temperature sensor 62b for measuring the temperature in the second temperature zone 2b.

The compressor 50 has a variable speed, i.e. it can be operated by the controller 60 at several different speeds> 0.

It conveys the cooling medium to the condenser 52, where it condenses out with the emission of heat. The liquid cooling medium then flows to the changeover valve 54.

The switching valve 54 is controlled by the controller 60. In the present embodiment, the flow of the cooling liquid between the throttles or capillaries 56a, 56b can thus be switched.

The first capillary 56a leads from the changeover valve 54 to the input of the first evaporator 40 already described. The second capillary 56b leads from the changeover valve 54 to the input of the second evaporator 58.

In the present embodiment, the second evaporator 58 is assigned to a freezer compartment 64. This is thermally separated from the utility room 2 and it is usually operated at a lower temperature than the utility room 2, e.g. at a target temperature of -25 ° C to -10 ° C.

There is preferably no gas exchange between the freezer compartment 64 and the utility space 2.

With the switch valve 54, the cooling device, depending on the type of switch valve 54, can be operated in at least two operating modes.

In a first operating mode, the changeover valve 54 is set such that the cooling medium flows through the second capillary 56b. It first passes through the second evaporator 58, where it can (depending on the temperature conditions) evaporate at least in part. Then it reaches the first evaporator 40 via a connecting line 66.

In the second operating mode, the changeover valve 54 is set such that the cooling medium flows through the first capillary 56a. It thus bypasses the second evaporator 58 and enters the first evaporator 40 directly.

In both operating modes, the cooling medium enters the second evaporator 40 from below. The liquid phase of the cooling medium will thus accumulate in the lowest area of the evaporator 40. The upper limit of the liquid cooling medium is shown in FIG. 11, for example under reference number 68.

As discussed at the outset, the cooling effect of the first evaporator 40 is stronger below this upper limit 68 than above.

The cooling medium passes from the first evaporator 40 back to the compressor 50 via a return line 70.

CH 715 229 A1. The return line 70 can be coupled to the throttles or capillaries 56a, 56b via a heat exchanger 72. This improves the efficiency of the device.

The basic principle of the functioning of the device is illustrated schematically with reference to FIGS. 12 and 13. These figures show the usable space 2 with the first and second temperature zones 2a, 2b. The rear wall element 3 and the first evaporator 40 are also shown.

The cooling air duct is generally designated by the reference number 6. The fan is not shown.

The cooling air which flows through the suction openings into the cooling air duct 6a, 6b and from there through the blow-back openings 37a-38n, 43 back into the useful space 2 is illustrated by arrows.

As can be seen, the cooling air is drawn in from the first temperature zone 2a (arrows 72a). It flows down through the cooling air duct 6. In particular, it runs from top to bottom through the cooling section 13 along the first evaporator 40.

The cooling air enters the blow-back openings 38a-38n, 43 at various vertical positions.

If it passes through one of the upper blow-back openings (blow-back openings 38a-38m in the example above, arrows 72b), it flows into the first temperature zone 2a. If it passes through one of the lower blowback openings (blowback openings 38n and 43, arrows 72c), it enters the second temperature zone 2b.

The air is conveyed upward from the second temperature zone 2b through one or more gaps or openings 74 in the region of the intermediate wall 11 into the first temperature zone 2a.

The cooling effect of the first evaporator 40 depends on where the upper limit 68 of the liquid cooling medium is.

If this upper limit 68 is relatively high (as shown in FIG. 12 under reference number 68a), at least part of the cooling air is cooled before it flows back through the upper (“first”) blow-back openings 38a-38m into the first temperature zone 2a . A relatively strong cooling of the first temperature zone 2a can thus be achieved.

If the upper limit 68 of the liquid cooling medium is relatively low (as shown in FIG. 12 under reference number 68b), in particular below all of the “first” blow-back openings 38a-38m, only the air that is cooled by the lower (“second ») Blow-back openings 38n, 43 flow.

The controller 60 can affect the position of the upper limit 68 in various ways. Two possible control values are the following:

If the second evaporator 58 and a changeover valve 54 are provided, the upper limit 68 is lower with otherwise the same operating parameters if the cooling medium is first passed through the second evaporator 58 and only then through the first evaporator 40 than if it were directly from the changeover valve 54 is led to the first evaporator 40.

The upper limit 68 can also (even if no changeover valve is provided) be influenced by the delivery capacity of the compressor 50. If a high delivery rate is selected, the upper limit 68 is higher than if a lower delivery rate is selected.

Another important operating parameter of the cooling device is the delivery rate of the fan 10.

If this is very high, there is hardly any heat exchange between the evaporator 40 and the air, and the air which flows from the blow-back openings 38a-38n and 43 into the temperature zones 2a, 2b has essentially the same temperature as that Air that is sucked in, ie the temperature T1 of the first temperature zone 2a. If the temperature T2 of the second temperature zone 2b is lower than T1, the second temperature zone 2b is heated.

If the delivery rate of the fan 10 is lower, the air stays longer in the cooling section 13 and is noticeably cooled by the evaporator 40. Depending on the position of the upper limit 68 of the liquid phase in the evaporator 40, the lower or both temperature zones 2a, 2b can thereby be cooled.

If the delivery capacity of the fan 10 is very low, the air is cooled down considerably, but its cooling capacity is low due to the small volume flow.

The temperature control of the temperatures in the two temperature zones 2a, 2b is illustrated below with the aid of examples. T1 and T2 denote the instantaneous temperatures in the first and second temperature zones 2a, 2b and Tisoll and T2soll their target temperatures. A “high liquid level” in the evaporator 40 is also a state in which the upper limit 68 of the liquid cooling medium in the evaporator 40 lies above at least the lowest first blow-back opening 38m, preferably above at least half of the first blow-back openings 38a-38n, in particular above all of the first blow-back openings 38a-38n. A “low liquid level” in the evaporator 40 refers to a state in which the upper limit 68 of the liquid cooling medium in the evaporator 40 lies below the lowest first blow-back opening 38m, in particular, however, above a part, preferably every second blow-off openings 38n, 43. Possible measures for influencing the upper limit 68 are described above.

If T1 <T1 target and T2 <T2 target: The controller 60 controls the device in such a way that the deepest liquid level in the evaporator 40 is at most, in order to reduce the cooling capacity. The upper limit 68 is advantageously set so low that

CH 715 229 A1 that at least some of the second blow-back openings 38n, 43 are above the upper limit 68. In addition, the controller 60 can at least temporarily increase the delivery capacity of the fan 10. Both measures reduce the cooling of the air in the cooling air duct 6.

If T1 <Ti target and T2> T2 target: The controller 60 controls the device so that the low liquid level is established in the evaporator 40, so that primarily only the air flowing into the second temperature zone 2 b is cooled. At the same time, the delivery rate of the fan can, if necessary, be reduced at least temporarily in order to greatly cool the air that enters the second temperature zone 2b.

If T1> Tisoll and T2 <T2soll: The controller 60 controls the device in such a way that the high liquid level is established in the evaporator 40, so that the air flowing into the first temperature zone 2a is also cooled. At the same time, the delivery rate of the fan is preferably chosen to be at least temporarily so great that the air in the air duct 6a, 6b has no time to cool down significantly, so that its temperature when it passes through the second blow-back openings 38n, 43 has a temperature greater than T2soll. At the same time, however, it advantageously has a temperature of less than Ti, so that it contributes to cooling the first temperature zone 2a.

If T1> T1 target and T2> T2 target: The controller 60 controls the device so that the high liquid level is established in the evaporator 40, so that the air flowing into the first temperature zone 2a is also cooled. At the same time, the delivery rate of the fan is selected at least temporarily so low that the air in the air duct has enough time to cool down so strongly that its temperature when passing through the second blow-back openings 38n, 43 is less than T2soll, and that its temperature is at Passing through at least part of the first blow-back openings 38a-38m has a temperature lower than Tisoll.

This type of control works for T2 setpoint <Ti setpoint in relatively wide ranges.

A further manipulated variable is the speed or delivery capacity of the compressor 50. By increasing the speed, the cooling capacity can be increased and the evaporation temperature reduced at the same time. Conversely, the cooling capacity can be reduced and the evaporation temperature increased by reducing the speed.

Remarks:

Advantageously, the first temperature zone 2a is a cooling compartment with a target temperature T1 target between 0 ° and 10 ° C, in particular between 2 and 7 ° C.

The second temperature zone 2b is a cold storage compartment with a target temperature T2set between -2 ° and 3 ° C, in particular between 0 ° and 3 ° C.

Advantageously, the difference T1 setpoint T2 should be at most 10 ° C, in particular at most 5 ° C, e.g. to keep the condensation in the cold areas low.

The delivery rate of the fan 10 should be controllable in a range sufficient to carry out the above measures. For a refrigerator with a usable space 2 of 200 liters, a delivery rate in the range of 10 to 30 m ³ / h has proven to be expedient, for example. Other funding options are conceivable. They depend, among other things, on the size of usable space 2 and the operating parameters of the heat pump and can be determined experimentally or mathematically.

In the example above, two temperature zones 2a, 2b are provided. However, more than two temperature zones can also be provided.

Advantageously, the temperature zones are arranged one above the other and / or separated from one another by horizontal partition walls 11.

The at least one suction opening 7a-7i is arranged higher than the blow-back openings 38a-38n, 43, or with the fan 10, the air is guided from top to bottom through the cooling section 13, so that the strong temperature gradient in the evaporator 40 is more efficient Way can be used to control the temperatures.

In the embodiment shown, at least one of the suction openings 7a-7i opens into the first temperature zone 2a. All the suction openings 7a-7i advantageously open into the first temperature zone. However, it is conceivable that at least one suction opening also opens into the second temperature zone 2b.

In the area of the temperature zones 2a, 2b, the fan 10 advantageously conveys the air from bottom to top, i.e. the air passes from the lower, second temperature zone 2b into the upper, first temperature zone 2a.

[0115] In the above examples, a refrigerator is shown. However, the refrigerator can e.g. can also be designed as a freezer or wine cooler or for other refrigerated goods, and / or it can be a combination device with several cooling zones for different temperatures.

The cooling air duct can also be arranged at least partially or completely elsewhere in the device, e.g. in a side wall.

As mentioned, the freezer compartment 64 is optional.

CH 715 229 A1 While preferred embodiments of the invention are described in the present application, it should be clearly pointed out that the invention is not limited to these and can also be carried out in other ways within the scope of the following claims.

Claims (13)

Claims 1. Cooling device with a useful space (2) with different temperature zones (2a, 2b), a heat pump (50, 52, 56a, 56b, 40, 58) comprising a compressor (50) for conveying a cooling medium, a condenser (52) and at least one first evaporator (40), a cooling air duct (6a, 6b), which is connected to the usable space (2) via at least one suction opening (7a-7i) and several blow-back openings (38a-38n, 43), the first evaporator ( 40) is arranged along a cooling section (13) of the cooling air duct (6a, 6b) and the blow-back openings (38a-38n, 43) of the cooling section (13) are arranged along different, vertically spaced positions, a fan (10), to convey air in the cooling air duct (6a, 6b) from the suction opening (7a-7i) to the blow-back openings (38a-38n, 43) and a controller (60) which is designed to operate in the different temperature zones (2a, 2b) maintain different target temperatures, characterized in that the compressor (50) is configured to convey the cooling medium from bottom to top along the first evaporator (40) and in that the controller (60) is configured to supply a quantity of liquid medium in the first evaporator (40) depending on the target temperatures and the actual temperatures in the temperature zones (2a, 2b). 2. Cooling device according to one of the preceding claims, wherein the controller (60) is configured to an upper limit (68) of liquid cooling medium in the first evaporator (40) depending on the target temperatures and the actual temperatures in the temperature zones (2a, 2b) above or below at least one first blow-back opening (38a-38m). 3. The cooling device according to claim 2, wherein a second blow-back opening (38n, 43) is arranged lower than the first blow-back opening (38a-38m). 4. Cooling device according to one of claims 2 or 3 with a first temperature zone (2a) and a second temperature zone (2b), wherein the first blow-back opening (38a-38m) opens into the first temperature zone (2a) and the second blow-back opening (38n, 43 ) opens into the second temperature zone (2b). 5. Cooling device according to one of the preceding claims, wherein the controller (60) is configured to control a delivery capacity of the fan (10) depending on the target temperatures and the actual temperatures in the temperature zones (2a, 2b). Cooling device according to claims 4 and 5, wherein the controller (60) is designed, depending on the temperature T1 in the first temperature zone (2a), the target temperature T1 in the first temperature zone (2a), the temperature T2 in the second Temperature zone (2b) and the target temperature T2soll in the second temperature zone (2b) to control the cooling device in such a way that at T1 <Tisoll and T2 <T2soll the evaporator (40) at most has a low liquid level, and in particular that the delivery rate of the fan ( 10) is increased at least temporarily, and / or in the case of T1 <Tisoll and T2> T2, a low liquid level is established in the evaporator (40), and in particular that the delivery capacity of the fan (10) is increased at least temporarily, and / or in T1> T1 should and T2 <T2 should a high liquid level occur in the evaporator (40), and in particular that the delivery rate of the fan (10) is at least temporarily so great that the two The air flowing through the blow-back opening (38n, 43) has a temperature greater than T2soll, and / or at T1> Ti Soll and T2> T2soll the high liquid level is established in the evaporator (40), and in particular that the delivery rate of the fan (10) is at least temporarily is so low that air flowing through the second blow-back opening (38n, 43) should have a temperature lower than T2 and through the first blow-back opening (38a-38m) should have a temperature lower than T1, the "high liquid level" describing a state in which an upper limit (68) of liquid cooling medium in the first evaporator (40) lies above at least a lowermost first blow-back opening (38m), preferably above at least half of the first blow-back openings (38a-38m), in particular above all of the first blow-back openings (38a-38m) , and wherein the “low liquid level” describes a state in which the upper limit (68) of the liquid cooling medium in the first vaporization it (40) lies below the lowermost first blow-back opening (38m), in particular above a part, preferably all of the second blow-back openings (38n, 43), and where T2soll <Tisoll. 7. Cooling device according to one of the preceding claims, wherein the blow-back openings (38a-38n, 43) are not assigned any controlled closure means. CH 715 229 A1 8. Cooling device according to one of the preceding claims, wherein between the condenser (52) and the first evaporator (40) at least two throttles (54a, 54b) are arranged, and wherein a changeover valve (54) is provided to a relative flow between the to vary both throttles (54a, 54b), and wherein the control (60) is designed to control the amount of liquid medium in the first evaporator (40) at least via the changeover valve (54). 9. Cooling device according to claim 8, wherein at least a second evaporator (58) is provided, and wherein a first of the throttles cooling medium from the compressor (50) past the second evaporator (58) to the first evaporator (40) and a second of the throttles cooling medium leads from the compressor (50) to the second evaporator (58), and in particular wherein the cooling device has a freezer compartment (64) in addition to the usable space (2), and wherein the second evaporator (58) is assigned to the freezer compartment (64). 10. Cooling device according to one of the preceding claims, wherein the controller (60) is configured to control a delivery capacity of the compressor (50) depending on the target temperatures and on actual temperatures in the temperature zones (2a, 2b). 11. The cooling device according to one of the preceding claims, wherein the suction opening (7a-7i) is arranged higher than the blow-back openings (38a-38n, 43), and in particular wherein the suction opening (7a-7i) is arranged above the first evaporator (40) . 12. Cooling device according to one of the preceding claims, wherein with the fan (10) air from bottom to top through the temperature zones (2a, 2b) can be conveyed. 13. The method for operating the cooling device according to one of the preceding claims, wherein the amount of liquid cooling medium in the first evaporator (40) is controlled depending on the target temperatures and the actual temperatures in the temperature zones, and in particular wherein a delivery capacity of the compressor (50) and / or a delivery rate of the fan (10) is controlled depending on the target temperatures and the actual temperatures in the temperature zones (2a, 2b). CH 715 229 A1