WO2017140494A1

WO2017140494A1 - Refrigeration device comprising multiple storage chambers

Info

Publication number: WO2017140494A1
Application number: PCT/EP2017/052044
Authority: WO
Inventors: Andreas BABUCKE; Niels Liengaard
Original assignee: BSH Hausgeräte GmbH
Priority date: 2016-02-19
Filing date: 2017-01-31
Publication date: 2017-08-24
Also published as: DE102016202564A1; US20190032985A1; EP3417212A1; PL3417212T3; CN108700346A; EP3417212B1

Abstract

The invention relates to a refrigeration device comprising at least one first and one second storage chamber (26, 27) and a refrigerant circuit in which a first throttle point (9), a first heat exchanger (10) for regulating the temperature of the first storage chamber (26), a second throttle point (13), and a second heat exchanger (14) for cooling the second storage chamber (27) are connected in series. A high pressure pipe section (18) upstream of the first throttle point (9) and a low pressure pipe section (16) downstream of the second heat exchanger (14) form a first inner heat exchanger (8). A bypass pipe (11) extends parallel to the high pressure pipe section (18) to the first heat exchanger (10), and a control valve (7, 32) is provided in order to control the distribution of the refrigerant to the high pressure pipe section (18) and the bypass pipe (11).

Description

Refrigerating appliance with several storage chambers

The present invention relates to a refrigeration appliance, in particular a domestic refrigeration appliance, with a plurality of storage chambers, which are operable at different temperatures. From DE 10 2013 226 341 A1, a refrigeration device with a plurality of storage chambers is known, in which a first throttle point, a first heat exchanger for controlling the temperature of the first storage chamber, a second throttle point and a second heat exchanger for cooling the second storage chamber are connected in series in a refrigerant circuit. The pressure drop at the second throttle point causes a pressure difference between the two heat exchangers, so that the evaporation temperature of the refrigerant in the second heat exchanger is lower than in the first and thus in the second storage chamber, a lower operating temperature can be set than in the first. Depending on the setting of the first throttle point, the first heat exchanger can work as an evaporator or as a condenser. When operating as a condenser, the operating temperature of the first storage chamber may be at room temperature or even slightly higher.

It is known per se to provide an internal heat exchanger in a refrigerator for improving the efficiency, in which a high-pressure line section in which refrigerant heated by compression circulates and a low-pressure line section in which refrigerant flows from an evaporator to a compressor in thermal Standing in contact. However, such an internal heat exchanger is useless if in a refrigerator with a plurality of storage chambers as described above, a first storage chamber to be operated at high temperature and for a lying in the refrigerant circuit downstream of the high-pressure line section of the inner heat exchanger evaporator of the storage chamber is operated as a condenser. A cooling of the second storage chamber is then possible only with limited energy efficiency.

Object of the present invention is to provide a refrigeration device with a plurality of storage chambers, which allows energy-efficient operation even if a high and a second storage chamber a low operating temperature is selected for a first storage chamber. The object is achieved by, in a refrigerator with at least a first and a second storage chamber and a refrigerant circuit, in which a first throttle, a first heat exchanger for controlling the temperature of the first storage chamber, a second throttle and a second heat exchanger for cooling the second storage chamber in series and a low pressure line section located downstream of the second heat exchanger forming a first inner heat exchanger, a bypass line extending parallel to the high pressure line section to the first heat exchanger, and a control valve for controlling the distribution of the refrigerant is provided to the high-pressure line section and the bypass line. If the first storage chamber is to be operated at high temperature, then the refrigerant can be directed via the shunt line directly to the first heat exchanger; In order to achieve energy-efficient operation at low temperature of the first storage chamber, the refrigerant is passed through the inner heat exchanger.

The bypass line is expediently also arranged parallel to the first throttle point. Thus, when the refrigerant circulates on the shunt line, not only cooling by the inner heat exchanger but also adiabatic cooling at the restriction can be avoided.

The control valve may be a directional control valve.

The directional control valve may form an upstream or a downstream end of the shunt line; preferably it forms the upstream end because there is a small line cross-section sufficient and a more compact and less expensive valve can be used, while a valve at the downstream end must be spacious enough to conduct even in the first throttle relaxed refrigerant without excessive pressure drop.

Alternatively, the control valve may be a shut-off valve arranged in the shunt line. When closed, such a check valve forces the entire refrigerant flow through the inner heat exchanger; are in the open state Although both ways, on the inner heat exchanger and the shunt line passable, but the effect of the inner heat exchanger is low, especially if the first throttle in series with the inner heat exchanger is parallel to the shunt line and directs the refrigerant into the shunt line. According to a further development, a third heat exchanger is arranged in a branch of the refrigerant circuit, which extends to the second heat exchanger, bypassing the first and second throttle point and the first heat exchanger. So still a third storage chamber can be tempered. In order to keep the third storage chamber at a different operating temperature than the first and the second storage chamber, the third heat exchanger in the branch is preferably preceded by a third throttle point and a fourth throttle point downstream. A medium pressure line section extending between the first heat exchanger and the second orifice and a second low pressure line section may form a second internal heat exchanger. The second inner heat exchanger contributes to an energy-efficient operation, in particular, when the refrigerant, in order to keep the first storage chamber at a high operating temperature, is directed past the first inner heat exchanger.

Alternatively, a third heat exchanger in the refrigerant circuit downstream of the first heat exchanger and upstream of the second heat exchanger. In this case, a second inner heat exchanger may be formed by a medium-pressure line section extending between the first heat exchanger and a third throttle point upstream of the third heat exchanger, and a second low-pressure line section. The control valve is coupled to a temperature sensor of the first storage chamber to control the distribution of the refrigerant to the high pressure line section and the bypass line depending on the temperature detected by the temperature sensor. Thus, if necessary, the temperature of the refrigerant, which in the Heat exchanger of the first storage chamber passes, varies and - if the bypass line bypasses the first throttle point - if necessary, also be switched between condenser and evaporator operation of the first heat exchanger. In this way, operating temperatures close to the ambient temperature can be maintained in the first storage chamber, which can not be reliably realized at a fixed predetermined position of the directional control valve.

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

Fig. 1 is a schematic representation of the refrigerant circuit according to a first

Embodiment of the refrigeration device according to the invention;

Fig. 3 is a modification of a detail of Fig.1; and

Fig. 3 is an illustration of the refrigerant circuit according to a second embodiment.

The refrigerant circuit shown in Fig. 1 comprises a speed-controlled compressor 1 with a pressure port 2 and a suction port 3. A flowing from the pressure port 2 high-pressure refrigerant line 4 runs in the direction of circulation of the refrigerant first via a condenser 5 and a branch 6 to a directional control valve. A section of the high-pressure refrigerant line 4 leads from a first output of the directional control valve 7 via an inner heat exchanger 8 and a first throttle point 9 to a heat exchanger 10 which is assigned to a first storage chamber 26 of the refrigeration device. A bypass line 1 1 connects a second output of the directional control valve 7 directly, bypassing the inner heat exchanger 8 and the throttle point 9, with the heat exchanger 10th

An output of the heat exchanger 10 is connected via a second inner heat exchanger 12 and a second throttle point 13 with a heat exchanger 14 which is associated with a second storage chamber 27. A low-pressure refrigerant line 15 extends from an exit of the heat exchanger 14 via the second inner heat exchanger 12 and the first inner heat exchanger 8 back to the suction port 3.

The inner heat exchangers 8, 12 each comprise a section 16 or 17 of the low-pressure line 15 and a section 18 of the high-pressure refrigerant line 4 or a line section 19 under a medium pressure which is in close heat-conducting contact at the low-pressure line section 16 or 17 attached, eg soldered, is or is guided within the relatively spacious low-pressure line section 16 and 17 respectively. The high-pressure or medium-pressure sections 18 and 19 may themselves be part of the adjacent throttle point 9 or 13, for example, in that they are designed as capillaries.

On a branch 20, which separates at the junction 6 of the high-pressure refrigerant line 4, there are a third throttle 21, a third bearing chamber 28 associated heat exchanger 22 and a fourth orifice 23. A section 24 of the line branch 16 extends here in the first inner heat exchanger 8 in thermal contact with the same low pressure line section 16 as the high pressure line section 18; alternatively, it could form a third internal heat exchanger together with another portion of the low pressure line 15. The branch 16 terminates at a confluence 25, downstream of the second orifice 13 and upstream of the second heat exchanger 14.

The throttling points 9, 13, 21, 23 can all be designed as capillaries with a fixed, unchangeable flow conductance. In order nevertheless to be able to control the intensity of the heat exchange between the bearing chambers 26, 27, 28 and the refrigerant at the heat exchangers 10, 14, 22 according to need, fans 29 are provided in the bearing chambers 26, 27, 28 which, if required, are assigned to the bearing chamber Blow heat exchanger 10, 14 or 22 respectively. Alternatively, expansion valves, with controllable Strömungsleitwert, as throttling points 9, 13, 21, 23 find use. Although the fans 29 are then not necessarily necessary to regulate the temperatures of the storage chambers 26, 27, 28; can but still be advantageously provided to control in addition to the temperature and the humidity in the storage chambers 26, 27, 28.

Another fan 30 may be provided on the condenser to intensify the heat exchange there, if necessary.

When the compressor 1 is in operation, compressed refrigerant after a first cooling in the condenser 5 to branch 6. The refrigerant is at least to a large extent liquid, its temperature is depending on the dimensions of the condenser by some degrees higher than the ambient temperature. A portion of the refrigerant flows via the throttle point 21, the heat exchanger 22 and the throttle point 23 to the heat exchanger 14 and from there back to the suction port third

When the directional control valve 7 is in the position shown in FIG. 1, the remainder of the refrigerant flows via the inner heat exchanger 8 and the throttle point 9, the heat exchanger 10 and the throttle point 13 to the heat exchanger 14.

The pressure in the evaporator 14 is low enough to allow operation of the storage chamber 27 as a freezer compartment, the pressure in the heat exchangers 10, 22 is between that of the condenser 5 and that of the heat exchanger 14 and allows operation of the storage chambers 26, 28, for example Fresh refrigerated compartment or as a normal refrigerated compartment. In order to realize higher temperatures, for example for operation as a basement compartment, in one of the storage chambers 26, 28, the ambient temperature would have to be reliably far enough above the desired compartment temperature. In contrast, when the directional control valve 7 is open to the bypass line 1 1, the pressure difference between the condenser 5 and the heat exchanger 10 is negligible, and the temperature that sets in the heat exchanger 10 is the common pressure of condenser 5 and heat exchanger 10 corresponding evaporation temperature of the refrigerant. The heat exchanger 10 then operates as a second condenser, which delivers heat to the storage chamber 15. The storage chamber 26 reaches in this way temperatures above ambient temperature and can therefore be used for rapid thawing or heating of food or for fermentation, such as to let go of dough or yogurt preparation. In this operating state, the temperature of the refrigerant at the outlet of the heat exchanger 10 is generally still above the ambient temperature. In this case, the second inner heat exchanger 12 ensures a cooling of the refrigerant before reaching the throttle point 13 and thus enables efficient cooling of the storage chamber 27th

The storage chambers 26, 27, 28 can each be equipped with a temperature sensor in a manner known per se, in order to determine the speed of the compressor 1 and the flow control values of the throttle points based on a comparison of the actual temperatures in the storage chambers 26, 27, 28 with set values set by the user 9, 13, 21, 23 and / or to control the speeds of the fans 29. According to a development of the invention, a temperature sensor 31 of the storage chamber 26 additionally serves to control the directional control valve 7: deviates significantly from the setpoint value downwards, while the directional control valve 7 is in the position shown in FIG. 1 and none of the other storage chambers 27 , 28 has cooling demand, then the directional control valve 7 is switched to direct hot refrigerant via the shunt line 1 1 in the heat exchanger 10. Conversely, the directional control valve 7 is returned to the position of FIG. 1, when the inflow of the hot refrigerant, the temperature of the storage chamber 26 can differ significantly from the target value upwards. In this way, set temperatures which are close to the ambient temperature and which, when the ambient temperature fluctuates, can sometimes be higher and lower than those in the storage chamber 26 can be maintained.

FIG. 2 shows a detail of the refrigerant circuit of a refrigerator according to a modified embodiment. The directional control valve 7 of FIG. 1 is here replaced by a shut-off valve 32 in the bypass line 1 1. The parallel to the bypass line 1 1 way to the heat exchanger 10 via the high-pressure line section 18 and the throttle point 9 is constantly open. The operation of this refrigerant circuit is not significantly different from that shown in Fig. 1. If the shut-off valve 32 is closed, the refrigerant can also reach in this embodiment, the heat exchanger 10 only via the throttle point 9. When the shut-off valve 32 is open, the path across the restriction 9 does not significantly contribute to the refrigerant flow. 3 shows a simplified refrigerant circuit according to a second embodiment of the invention. Components of the refrigerant circuit denoted by the same reference numerals as in FIG. 1 each have the same function as described with reference to FIG. Again, the refrigerator has three storage chambers 26, 27, 28, however, the heat exchanger 22 of the storage chamber 28 and the heat exchanger 22 upstream throttle body 21 between the line section 19 of the second inner heat exchanger 12 and the throttle body 13 is inserted, so that a series circuit of Heat exchanger 10, 22, 14 of all three storage chambers 26, 27, 28 results. The structure of the refrigerant circuit is simplified compared to FIG. 1, since the branch 6, the throttle point 23 and the confluence 25 are omitted. The only limitation that must be accepted for this is that the setpoint temperature of the storage chamber 26 here can not be lower than that of the storage chamber 28. The ability to operate the storage chamber 26 at temperatures near or above ambient temperature is the same here Of course, here too, the directional control valve 7 can be replaced by a shut-off valve in the bypass line 1 1, and a temperature sensor of the storage chamber 27 can serve to control the position of the directional control valve 7 or the shut-off valve.

REFERENCE NUMBERS

1 compressor

2 pressure connection

3 suction connection

4 high pressure refrigerant line

5 liquefier

6 branching

7 way valve

8 inner heat exchanger

9 throttle point

10 heat exchangers

1 1 shunt line

12 inner heat exchanger

13 throttle point

14 heat exchangers

15 low-pressure refrigerant line

16 low-pressure line section

17 low-pressure line section

18 high-pressure line section

19 medium-pressure line section

20 line branch

21 throttle point

22 heat exchangers

23 throttle point

24 line section

25 confluence

26 storage chamber

27 storage chamber

28 storage chamber

29 fan

30 fans

31 temperature sensor 32 stop valve

Claims

Refrigerating appliance having at least a first and a second storage chamber (26, 27) and a refrigerant circuit, in which a first throttle point (9), a first heat exchanger (10) for controlling the first storage chamber (26), a second throttle point (13) and a second heat exchanger (14) for cooling the second storage chamber (27) are connected in series, characterized in that a high-pressure line section (18) located upstream of the first throttle point (9) and a low-pressure section located downstream of the second heat exchanger (14). A passage portion (16) forming a first inner heat exchanger (8), a bypass line (1 1) extending parallel to the high-pressure line section (18) to the first heat exchanger (10), and a control valve (7, 32) for controlling the distribution of Refrigerant on the high-pressure line section (18) and the bypass line (1 1) is provided.

Refrigerating appliance according to claim 1, characterized in that the bypass line (1 1) is further arranged parallel to the first throttle point (9).

Refrigerating appliance according to claim 1 or 2, characterized in that the control valve is a directional control valve (7).

Refrigerating appliance according to claim 3, characterized in that the directional control valve (7) forms an upstream end of the bypass line (1 1).

Refrigerating appliance according to claim 1 or 2, characterized in that the control valve in the bypass line (1 1) arranged shut-off valve (32).

Refrigerating appliance according to one of claims 1 to 5, characterized in that a third heat exchanger (22) in a branch (20) of the refrigerant circuit is arranged, bypassing the first and second throttle point (9, 13) and the first heat exchanger (10 ) extends to the second heat exchanger (14).

7. Refrigerating appliance according to claim 6, characterized in that the third heat exchanger (22) in the branch (20) upstream of a third throttle point (21) and a fourth throttle point (23) is connected downstream.

8. Refrigerating appliance according to claim 6 or 7, characterized in that a medium-pressure line section (19) which extends between the first heat exchanger (10) and the second throttle point (13), and a second low-pressure line section (17) has a second form inner heat exchanger (12).

9. Refrigerating appliance according to one of claims 1 to 5, characterized in that a third heat exchanger (22) downstream of the first heat exchanger (10) in the refrigerant circuit and the second heat exchanger (14) is connected upstream.

10. Refrigerating appliance according to claim 9, characterized in that a medium-pressure line section (19) extending between the first heat exchanger (10) and a third heat exchanger (22) upstream third throttle body (21), and a second low-pressure line section (17) form a second internal heat exchanger (12).

1 1. Refrigerating appliance according to one of the preceding claims, characterized in that the permeability of at least one of the throttle points (9, 13, 21, 23) is controllable.

12. Refrigerating appliance according to one of the preceding claims, characterized in that at least one of the heat exchangers (10, 14, 22) is associated with a fan (29).

13. Refrigerating appliance according to one of the preceding claims, characterized in that the control valve (7, 32) to a temperature sensor (31) of the first storage chamber (26) is coupled to the distribution of the refrigerant to the

High-pressure line section (18) and the bypass line (1 1) depending on the temperature sensor (31) detected temperature to control.