DE102016210135A1 - Refrigerating appliance with rapid cooling function and operating method for it - Google Patents

Abstract

A refrigerator has a hot and a cold storage compartment (8, 9), a chiller, a first heat exchanger (6) for extracting heat from the warm storage compartment (8), a second heat exchanger (7) for removing heat from the cold Storage compartment (9) and an ambient heat exchanger (4) for discharging the extracted heat, and a heat transfer in which between a pressure port (15) and a suction port (16) of a heat transfer medium circulating pump (14) in thermal contact with the hot Storage compartment (8) standing third heat exchanger (12; 21), a shut-off valve (17) and in thermal contact with the cold storage compartment (9) standing fourth heat exchanger (13) are connected in series.

Description

The present invention relates to a refrigerator with a rapid cooling function for cooling of limited quantities of refrigerated goods such as the filling of an icemaker, a beverage container or the like and an operating method for such a refrigerator.

Conventional blast chillers usually use the chiller in a refrigeration appliance for cooling the storage compartment or the storage compartments and a fan which directs cold air from an evaporator of the chiller to an object to be cooled. The cooling capacity of such a blast chiller can therefore never be greater than that of the chiller itself.

Since blast chillers and storage compartments must share the refrigeration capacity of the chiller, there is a conflict when a user uses the rapid cooling function and at the same time requires cooling in a storage compartment, because at least that part of the cooling capacity that actually absorbs from the object to be cooled by the blast chiller is no longer available for cooling the storage compartment. Thus, in case of conflict, either the cooling of the storage compartment or that of the item in the blast chiller is delayed.

The object of the invention is to provide a refrigerator with quick cooling function and a method for rapid cooling, which are not subject to the restrictions described above.

The object is achieved by a second heat exchanger for extracting heat from the cold storage compartment and a surrounding heat exchanger for dispensing of a refrigeration device with a hot and a cold storage compartment and a chiller, the first heat exchanger for extracting heat from the warm storage compartment entzogenen heat, a heat transfer circuit is provided in which are connected between a pressure port and a suction port of a heat transfer pump circulating a third heat exchanger in thermal contact with the warm storage compartment, a shut-off valve and a fourth heat exchanger in thermal contact with the cold storage compartment in series ,

A refrigeration appliance is understood in particular to be a household refrigeration appliance, that is to say a refrigeration appliance which is used for household purposes or possibly also in the gastronomy sector and serves, in particular, to store foods and / or drinks in household quantities at specific temperatures, such as, for example, a refrigerator Freezer, a fridge freezer, a freezer or a wine storage cabinet.

The third heat exchanger is provided to store therein a heat carrier in liquid state and in thermal equilibrium with the warm storage compartment until use. If at the same time the fourth heat exchanger is in thermal equilibrium with the cold storage compartment, the pressure in both heat exchangers is equal to the saturation vapor pressure of the heat carrier at the respective compartment temperature. To cool refrigerated goods quickly, this can be placed in close contact with the third heat exchanger and the shut-off valve can be opened; then the pressure in the third heat exchanger drops quickly, the liquid heat carrier begins to evaporate, and the third heat exchanger cools down quickly. Recondensation of the heat carrier in the fourth heat exchanger keeps the pressure low in both heat exchangers, so that a considerable amount of the liquid heat carrier stored in the third heat exchanger can evaporate.

The refrigerating machine may in turn have a refrigerant circuit to which the first and the second heat exchanger belong, but this refrigerant circuit is separated from the heat transfer medium. Also, the heat carrier circulating in the heat transfer medium can be different from the refrigerant of the refrigerant circuit and adapted to the specifics of the heat transfer medium.

For example, the third heat exchanger should be as thin-walled as possible to achieve a fast cooling effect. Consequently, however, the pressure of the heat carrier in the third heat exchanger should not be too high. Therefore, a heat carrier is preferably selected, the saturation vapor pressure at the temperature of the warm storage compartment is a maximum of 2.0 bar.

On the other hand, the saturation vapor pressure should also not be too low in order to achieve a high mass flow to the fourth heat exchanger in the application. Therefore, the saturation vapor pressure at the temperature of the warm storage compartment should be minimally 1.0 bar.

For the heat transfer circuit to make do with a low-cost, low-compression pump, the difference between the saturation pressures of the heat carrier at the temperature of the cold storage compartment and the warm storage compartment should not be greater than 1.5 bar.

These requirements are met in particular by butane or isobutane as a heat transfer medium.

The amount of liquid heat transfer medium that can be accommodated in the third heat exchanger should be sufficient to produce an adequate amount of ice for one or two portions of drinks or to bring a beverage container from room temperature to drinking temperature with the cold produced during its evaporation, but at the same time not so large that one must expect a freezing of the contents of the container. Therefore, a capacity of the first evaporator corresponding to a latent heat of the refrigerant contained therein of 10-50 kJ is appropriate. Particularly preferred is a capacity corresponding to a latent heat of 15-25 kJ. This amount is sufficient to cool the contents of a beverage can (typically 0.33 L) from 25 ° C to 10 ° C, or to produce 60 g of ice from 5 ° C warm water.

The passage cross-section of the shut-off valve in the open position should be as large and in particular large enough to limit the actual vapor pressure in the third heat exchanger to not more than the average of the vapor pressure in the fourth heat exchanger and the saturation vapor pressure of the third heat exchanger.

The capacity of the heat carrier in the heat transfer circuit should be such that at maximum filling of the third heat exchanger with liquid heat carrier, i. when the heat transfer medium is pumped so completely into the third heat exchanger, that in the rest of the heat carrier circuit possibly still heat transfer steam is present, leading to the shut-off outlet of the third heat exchanger is above the liquid level. This ensures that no liquid heat carrier escapes from the third evaporator when opening the shut-off valve.

If the third heat exchanger at maximum filling with liquid heat carrier has a vapor volume through which the outlet communicates with an inlet of the third heat exchanger, no liquid heat carrier can be displaced to the outlet by the expansion of existing in the third heat exchanger when opening the shut-off valve heat transfer steam.

In order to achieve a rapid recondensation of the heat carrier in the fourth heat exchanger and a correspondingly rapid evaporation in the third heat exchanger, a phase change medium can be arranged on the fourth heat exchanger.

In particular, if the fourth heat exchanger itself contains the phase change medium, preferably in the form of a bed of particles containing the phase change medium, extremely small heat exchange between the heat transfer steam flowing into the fourth heat exchanger and the phase change medium is possible on a small volume.

The melting latent heat of the phase change medium should correspond to the evaporation latent heat of the heat carrier, so that it is sufficient to recondense in a rapid cooling process to unavoidable residual steam, the entire heat transfer in the fourth heat exchanger.

A valve may be disposed in the heat carrier circuit between the pressure port and the third heat exchanger, e.g. to prevent pressure equalization between the third and fourth heat exchanger via the pump when the pump is at standstill.

The valve may also be a metering valve, with which the amount of the liquid heat carrier in the third heat exchanger can be adapted to the heat capacity of a good to be cooled.

Such a metering valve can be preceded by a storage container in thermal contact with the warm storage compartment to retain liquid heat carrier, which is not needed for cooling the goods, while the required amount is introduced into the third heat exchanger.

• a) Sammeln eines Wärmeträgers in einem Wärmetauscher des warmen Lagerfachs in flüssigem Zustand;
• b) Öffnen eines Durchgangs für den Wärmeträger in dampfförmigem Zustand zu einem Wärmetauscher des kalten Lagerfachs;
• c) Kondensieren des dampfförmigen Wärmeträgers im kalten Lagerfach.

The object is further achieved by a method for rapid cooling in a refrigerator with a hot and a cold storage compartment, with the steps

• a) collecting a heat carrier in a heat exchanger of the warm storage compartment in the liquid state;
• b) opening a passage for the heat carrier in the vapor state to a heat exchanger of the cold storage compartment;
• c) condensing the vaporous heat carrier in the cold storage compartment.

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

1 a block diagram of a refrigerator according to a first embodiment of the invention;

2 a block diagram according to a second embodiment;

3 a block diagram according to a third embodiment;

4 a fourth heat exchanger of the refrigerator in longitudinal section;

5 a variant of the fourth heat exchanger in cross section;

6 a third heat exchanger of the refrigerator in perspective view;

7 a modification of the third heat exchanger in section; and

8th a view of the third heat exchanger 7 from underneath.

1 shows a block diagram of a refrigerator according to a first embodiment of the invention. The refrigeration device is a combination device with at least one hot and one cold storage compartment 8th respectively. 9 , typically a normal refrigerated compartment and a freezer, which are cooled by a refrigerator of any type. An example of a compression refrigeration machine is shown in which one of a pressure connection 2 a compressor 1 outgoing refrigerant line 3 in a conventional manner via a designed as a condenser ambient heat exchanger 4 and a throttle point 5 to here as evaporators trained heat exchangers 6 . 7 the storage compartments 8th . 9 and from there back to a suction port 10 of the compressor 1 runs.

To ensure adequate cooling of the storage compartment 9 can ensure one here - as well as in the later described embodiments of 2 and 3 - on the refrigerant line 3 a directional valve 32 be provided, with which the refrigerant, bypassing the throttle point 5 and the heat exchanger 6 via a second throttle point 33 directly to the heat exchanger 7 can be fed.

Instead of a compression refrigeration machine, e.g. Also, a Peltier cooling are used, in which the ambient heat exchanger and the heat exchanger of the storage compartments with mutually complementary semiconductor junctions of Peltier elements are in thermal contact.

Parallel to the refrigerant line 3 extends a heat carrier line 11 through the storage compartments 8th . 9 and connects a heat exchanger 12 in the storage compartment 8th and a heat exchanger 13 in the storage compartment 9 with each other and with a pressure connection 15 and a suction port 16 a pump 14 , Between the two heat exchangers 12 . 13 is in the heat carrier line 11 a shut-off valve 17 arranged.

The of the heat transfer line 11 and the components connected to it 12 . 13 . 14 . 17 The heat carrier circuit formed contains a heat transfer fluid, which may or may not be identical to the refrigerant of the compression refrigeration machine. Preferably, the filling of the heat transfer medium consists of 45 to 55 g of butane or isobutane.

In a standby state of the heat transfer circuit is the shut-off valve 17 closed, and the heat exchanger 13 is through the pump 14 evacuated to a pressure equal to the saturation vapor pressure of the heat carrier at the temperature of the cold storage compartment 9 is equal to or less than that in the heat exchanger 13 no liquid heat carrier is present. Almost all of the heat transfer fluid is in the heat exchanger 12 concentrated and is there mostly in liquid form.

When a user wants to cool down refrigerated goods quickly, he places them in close contact with the heat exchanger 12 and opens the shut-off valve 17 , As the pressure of the heat transfer steam in the heat exchanger 12 higher than in the heat exchanger 13 , steam flows from the heat exchanger 12 to the heat exchanger 13 off, and the pressure in the heat exchanger 12 falls below the saturation vapor pressure. Thereafter, heat transfer medium evaporates in the heat exchanger 12 , this cools, and with him the refrigerated goods. Because at the same time the pressure in the heat exchanger 13 rises above the local saturation vapor pressure, the heat transfer condenses there, so that more steam from the heat exchanger 12 can overflow.

The pressure drop at the open shut-off valve 17 should be as low as possible, since any relaxation of the heat carrier on the way between the heat exchangers 12 . 13 the cooling effect in the heat exchanger 12 impaired. The opening cross-section should therefore be at least large enough, during the evaporation of a pressure in the heat exchanger 12 not greater than the average of the vapor pressure in the heat exchanger 13 and the saturation vapor pressure arising in the heat exchanger 12 with closed shut-off valve 17 would set.

Recondensation causes heat in the cold storage compartment 9 released. To prevent it from being chilled goods in the storage compartment 9 heated, the heat exchanger can 13 in close proximity to the heat exchanger 7 be arranged so that the heat of condensation introduced by the latter immediately back from the storage compartment 9 can be eliminated. It is also conceivable, a temperature sensor for controlling the compressor 1 at the heat exchanger 13 to install or the compressor 1 to the shut-off valve 17 to couple, so that every time you open the shut-off valve 17 the compressor 1 starts to run to the storage compartment 9 to cool.

Instead of such a coupling or in addition to it can on the heat exchanger 13 be mounted a thermal mass with high heat capacity, instead of the goods to be cooled of the storage compartment 9 in the heat exchanger 13 absorbs released condensation heat. According to a preferred development, the thermal mass is a phase change medium whose melting temperature is just above the temperature of the storage compartment 9 , in the case of a temperature of the storage compartment 9 from -18 ° C eg at -16 ° C is located.

Such a phase change medium can be in very close thermal contact with the heat transfer medium in the heat exchanger 13 stand and thereby to a rapid recondensation of the heat carrier in the heat exchanger 13 contribute. Thus, the entire liquid heat transfer heat exchanger 12 evaporate within a few seconds; Accordingly, the cooling capacity in the heat exchanger is high 12 ,

The amount of the phase change medium is such that its heat of fusion of the heat of condensation of the entire contents of the heat exchanger 12 equivalent. Thus, in an ideal case, the entire heat transfer medium from the heat exchanger 12 in the heat exchanger 13 recondensate, without this heated above the melting temperature of the phase change medium, and the heat input into the in thermal contact with the heat exchanger 13 standing storage compartment 9 can be kept to a minimum.

The phase change medium 18 can be like in 4 shown in the heat exchanger 13 itself as a bed of particles, preferably from coated with a shell of a solid plastic beads of the phase change medium, are present, wherein in the cavities of the bed of the heat transfer medium can circulate. It may also be in the form of one or more macroscopic, with the phase change material 18 filled hollow bodies are present, over the surface of which the heat transfer steam can strike, for example as in 5 shown in the form of an inner lining 19 of the heat exchanger 13 whose inside projecting inwards, with the phase change medium 18 filled ribs 20 having.

After the heat transfer medium in the heat exchanger 13 has passed, the shut-off valve 17 closed again, and the pump 14 is set in motion to return the liquid heat carrier to the heat exchanger 12 to relocate. Once completed this process and possibly the phase change medium 18 Frozen again, the heat transfer circuit is ready for use again.

A first modification of the heat transfer medium is in 2 shown. Here are in the warm storage compartment 8th between the pressure connection 15 the pump 14 and the heat exchanger 12 a storage tank 21 and a metering valve 22 intended. In standby mode, both heat exchangers are here 12 . 13 pumped, and the liquid heat carrier is in the storage tank 21 gathered. To prepare a rapid cooling process, the metering valve 22 open as long as necessary to the amount of heat transfer medium in the heat exchanger 12 to be dosed, which is used to cool a desired amount of heat exchanger 12 placed refrigerated goods is needed. For example, considering the size of one on the heat exchanger 12 placed to be placed beverage container, the amount of the heat carrier so that a large container is cooled satisfactorily, while the same amount of heat transfer would bring the contents to a smaller container for freezing. For controlling the metering valve 22 For example, a timer may be provided at which a user can adjust the volume of a container to be cooled, the timer controlling the metering valve 22 Keep open as long as necessary, so that the amount of heat transfer medium in the heat exchanger 12 which is needed to cool the set volume of liquid from room temperature to eg 5 ° C.

Because the storage tank 21 in the storage compartment 8th is arranged, it ultimately forms another heat exchanger, in which the heat transfer medium after passage through the pump 14 the temperature of the storage compartment 8th accepts. Therefore, the design of the 2 again in the in 3 modified here are shown: Here is the storage container 21 the only heat exchanger of the heat transfer circuit, in thermal contact with the warm storage compartment 8th stands; the heat exchanger 12 is outside the storage compartment 8th , For example, arranged in its own heat-insulated compartment, so that refrigerated goods on the heat exchanger 12 can be placed without the storage compartment 8th must be opened.

6 shows a first embodiment of the heat exchanger 12 , The heat exchanger 12 here has the shape of a hollow-walled cup sized to hold a bottle or soda can. At the outer periphery of the heat exchanger 12 be provided with a thermal barrier coating. The heat carrier line 11 flows at an inlet 23 into the cup wall near its upper edge, an outlet 24 , from which the heat carrier line 11 continue to the shut-off valve 17 runs, is also located at the top of the cup. The capacity of the cup wall is greater than the volume of the heat carrier in the liquid state, so that even if the heat carrier completely in the heat exchanger 12 is gathered, inlet and outlet 23 . 24 from the liquid level 25 through a coherent vapor volume 26 are separated and only heat transfer steam the outlet 24 can reach.

The cup shape allows it inside the heat exchanger 12 Fill water to a close thermal contact between the heat exchanger 12 and an object placed inside. When the heat exchanger 12 The capacity of its internal cavity is about 60 g R600a, sufficient to cool the can by 15 ° C. A designed for beverage containers of other volume heat exchanger 12 can each have a volume that deviates proportionally from this volume.

7 shows a section through an icemaker, the heat exchanger 12 according to a second embodiment. The heat exchanger 12 here includes a horizontal plate 27 and from the bottom of the plate 27 protruding ribs 28 , which together define a coherent cavity. Ribs 28 dive into a bowl filled with water 29 one. As in particular at the bottom view of the heat exchanger 12 in 8th to recognize, limit the intersecting ribs 28 indentations 30 , which are each open to the side, when the shell 29 is filled or the ribs 28 Immerse in the water to allow the escape of air. Also for venting can notches 31 at the edges of the plate 27 contribute.

If such an icemaker in a heat transfer of the in 2 or 3 shown type to be used, it may be useful if the amount of heat transfer in the heat transfer medium is greater than for freezing the water in the shell 29 required, and only the part of the heat carrier, which is needed for freezing of the heat carrier, is introduced into the heat exchanger. Then, after freezing the water, the metering valve 22 while opening the shut-off valve 17 remains closed. In this way, liquid heat transfer medium reaches the temperature of the storage compartment 8th in the heat exchanger 12 and thaw the ice up superficially, leaving each other touching surfaces of the shell 29 and the heat exchanger 12 do not stick to each other and the ice from the heat exchanger 12 solves. If the shell 29 is removed from the refrigerator, adhere the ice cubes in a regular arrangement at its bottom and can, as their flanks are exposed, are conveniently removed.

LIST OF REFERENCE NUMBERS

1

 compressor

2

 pressure connection

3

 Refrigerant line

4

 Ambient heat exchanger

5

 restriction

6

 heat exchangers

7

 heat exchangers

8th

 warehouse specialist

9

 warehouse specialist

10

 suction

11

 Heat transfer line

12

 heat exchangers

13

 heat exchangers

14

 pump

15

 pressure connection

16

 suction

17

 shut-off valve

18

 Phase change medium

19

 inner lining

20

 rib

21

 storage container

22

 metering valve

23

 inlet

24

 outlet

25

 liquid level

26

 steam volume

27

 plate

28

 rib

29

 Bowl

30

 indentation

31

 score

32

 way valve

33

 restriction

Claims (13)

Refrigerating appliance with a hot and a cold storage compartment ( 8th . 9 ), a chiller, which has a first heat exchanger ( 6 ) to remove heat from the warm storage compartment ( 8th ), a second heat exchanger ( 7 ) for removing heat from the cold storage compartment ( 9 ) and an ambient heat exchanger ( 4 ) for discharging the extracted heat, characterized by a heat carrier circuit in which between a pressure connection ( 15 ) and a suction connection ( 16 ) a heat transfer medium circulating pump ( 14 ) in thermal contact with the warm storage compartment ( 8th ) third heat exchanger ( 12 ; 21 ), a shut-off valve ( 17 ) and one in thermal contact with the cold storage compartment ( 9 ) fourth heat exchanger ( 13 ) are connected in series. Refrigerating appliance according to claim 1, characterized in that the heat carrier at the temperature of the warm storage compartment ( 8th ) has a saturation vapor pressure of a maximum of 2.0 bar and / or a minimum of 1.0 bar. Refrigerating appliance according to claim 1 or 2, characterized in that the difference between the saturation pressures of the heat carrier at the temperature of the cold storage compartment ( 9 ) and the warm storage compartment ( 8th ) is a maximum of 1.5 bar. Refrigerating appliance according to one of the preceding claims, characterized in that the capacity of the third heat exchanger ( 12 ; 21 ) for liquid heat carrier of a latent heat of 10-50 kJ, preferably 15-25 kJ corresponds. Refrigerating appliance according to one of the preceding claims, characterized in that the shut-off valve ( 17 ) in the open position, the vapor pressure in the third heat exchanger ( 12 ) to not more than the average value of the vapor pressure in the fourth heat exchanger ( 13 ) and the saturation vapor pressure of the third heat exchanger ( 12 ) limited. Refrigerating appliance according to one of the preceding claims, characterized in that the filling amount of the heat carrier is dimensioned such that at maximum filling of the third heat exchanger ( 12 ) with liquid heat transfer to the shut-off valve ( 17 ) leading outlet ( 24 ) of the third heat exchanger above the liquid level ( 25 ) lies. Refrigerating appliance according to claim 6, characterized in that the third heat exchanger ( 12 ) at maximum filling with liquid heat transfer medium, a vapor volume ( 26 ) via which the outlet ( 24 ) with an inlet ( 23 ) of the third heat exchanger ( 12 ) communicates. Refrigerating appliance according to one of the preceding claims, characterized in that on the fourth heat exchanger ( 13 ) a phase change medium ( 18 ) is arranged. Refrigerating appliance according to claim 8, characterized in that the melting latent heat of the phase change medium ( 18 ) corresponds to the evaporation latent heat of the heat carrier. Refrigerating appliance according to one of the preceding claims, characterized by a valve which in the heat transfer medium circuit between the pressure connection ( 15 ) and the third heat exchanger ( 12 ) is arranged. Refrigerating appliance according to claim 10, characterized in that the valve is a metering valve ( 22 ). Refrigerating appliance according to claim 11, characterized in that the metering valve ( 22 ) a storage container ( 21 ) in thermal contact with the warm storage compartment ( 8th ) is connected upstream. Method for rapid cooling in a refrigerating appliance with a hot and a cold storage compartment ( 8th . 9 ), with the steps a) collecting a heat carrier in a heat exchanger ( 12 ; 21 ) of the warm storage compartment ( 8th ) in the liquid state; b) opening a passage for the heat carrier in the vapor state to a heat exchanger ( 13 ) of the cold storage compartment ( 9 ); c) condensing the vaporous heat carrier in the heat exchanger ( 13 ) of the cold storage compartment ( 9 ).

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