Refrigerant circuit, refrigeration device and method for operating a refrigeration device

Abstract

A refrigerant circuit is provided with a first and a second evaporator connected in parallel. A collector is provided upstream of the throttles connected to the respective evaporator. The collector has several spatially separated connections or outlets, with at least one throttle connected to each connection. While the cooler second evaporator is being supplied with refrigerant, liquid refrigerant can be collected in the collector, which is then available for the subsequent supply to the warmer first evaporator without necessarily requiring a separate pumping process.

Description

TECHNICAL FIELD

[0001] The present invention relates to a refrigerant circuit, a refrigeration appliance, in particular a household refrigeration appliance such as a refrigerator, a freezer or a freezer chest or a fridge-freezer combination, and a method for operating a refrigeration appliance. STATE OF THE ART

[0002] Combination refrigeration appliances, such as refrigerator-freezers, have two or more separate storage compartments that are designed to maintain different temperatures. For example, a refrigerator-freezer may have a freezer compartment that typically operates between approximately -5°C and approximately -25°C, and a refrigerator compartment that typically operates between approximately 0°C and approximately +12°C.

[0003] In order to operate the different storage compartments at different temperatures, refrigerant circuits with multiple evaporators can be used, with each storage compartment assigned an evaporator and the individual evaporators connected in parallel to a condenser. The outlets of the individual evaporators are usually connected to a suction line that is connected to a compressor. A valve arrangement is usually provided to supply the individual evaporators with refrigerant. If only the evaporator for the warmer of the storage compartments is supplied with refrigerant, connecting several evaporators to the common suction line allows refrigerant to flow into the evaporator for the colder of the storage compartments. As a result, the vapor pressure and thus the temperature in the evaporator of the warmer storage compartment drops.

[0004] To counteract this, US Pat. No. 5,465,591 A describes a refrigerant circuit with a freezer compartment evaporator and a refrigerator compartment evaporator, the inlets of which are connected in parallel to a condenser and the outlets of which are connected to a common suction line. A check valve is provided between the outlet of the freezer compartment evaporator and the suction line to prevent an unwanted reduction in pressure in the refrigerator compartment evaporator when the refrigerator compartment evaporator is supplied with refrigerant. After the freezer compartment evaporator has been supplied, a pumping process takes place in which the supply lines to the evaporators are interrupted by a valve arrangement and a compressor is operated simultaneously. This sucks refrigerant out of the evaporators and feeds it to the condenser in order to provide sufficient liquid refrigerant when the refrigerator compartment evaporator is supplied again.

[0005] During the pumping process, the evaporation pressure and temperature in the freezer compartment evaporator become very low. If too little refrigerant is pumped, the refrigerator compartment evaporator may not be sufficiently filled, which not only reduces efficiency but can also lead to uneven frosting on the evaporator. SUMMARY OF THE INVENTION

[0006] It is one of the objects of the present invention to provide improved solutions for a refrigerant circuit of a refrigeration device, in particular solutions that allow an increase in efficiency in refrigerant circuits with evaporators connected in parallel.

[0007] This object is achieved according to the invention by a refrigerant circuit having the features of claim 1, a refrigeration device having the features of claim 9, and a method having the features of claim 11. Advantageous embodiments and further developments emerge from the subclaims referring back to the independent claims in conjunction with the description.

[0008] According to a first aspect of the invention, a refrigerant circuit for a refrigeration appliance, in particular for a household refrigeration appliance, comprises a condenser arrangement, a first evaporator for cooling a first storage compartment at a first temperature, and a second evaporator for cooling a second storage compartment at a second temperature which is lower than the first temperature, wherein the first evaporator and the second evaporator are connected in parallel to an outlet of the condenser. The refrigerant circuit further comprises a first throttle connected upstream of the first evaporator, e.g. in the form of a first capillary, a second throttle connected upstream of the second evaporator, e.g.in the form of a second capillary, a collector connected to the outlet of the condenser arrangement and designed to collect liquid refrigerant coming from the condenser arrangement, a switchable valve arrangement arranged between the collector and the throttles, and a compressor for circulating the refrigerant between the respective evaporator and the condenser arrangement. According to the invention, the collector has a first connection connected to the first throttle and a second connection connected to the second throttle.The valve arrangement is designed to alternately establish and separate a fluidic connection between the first connection and the first throttle in order to supply the first evaporator with liquid refrigerant from the collector or to interrupt the supply of refrigerant, and to establish or separate a fluidic connection between the second connection and the second throttle in order to supply the first evaporator with refrigerant or to interrupt the supply of refrigerant.

[0009] According to a second aspect of the invention, a refrigeration appliance is provided, in particular a household refrigeration appliance. The refrigeration appliance comprises a first storage compartment for operation at a first temperature, a second storage compartment for operation at a second temperature that is lower than the first temperature, and a refrigerant circuit according to the first aspect of the invention, wherein the first evaporator is thermally coupled to the first storage compartment and the second evaporator is thermally coupled to the second storage compartment.

[0010] According to a third aspect, a method for operating the refrigeration device according to the second aspect of the invention is provided. The method comprises operating the compressor to circulate refrigerant in the refrigerant circuit between at least one of the evaporators and the condenser, switching the valve arrangement such that the second evaporator is supplied with refrigerant to extract heat from the freezer compartment and fill the accumulator with liquid refrigerant, and switching the valve arrangement such that the first evaporator is supplied with refrigerant, wherein the first evaporator is filled with refrigerant from the accumulator immediately after switching.

[0011] One idea underlying the invention is to provide a collector in a refrigerant circuit with parallel-connected evaporators, upstream of the throttles connected to the respective evaporator. The collector has several spatially separated connections or outlets, with at least one throttle connected to each connection. For example, the connections can be positioned at different fill levels of the collector. The first connection of the collector, i.e., the connection to which the throttle connected to the warmest evaporator (first evaporator) is connected, is arranged such that liquid refrigerant collects there while the cooler second evaporator is supplied.

[0012] While the cooler second evaporator is being supplied with refrigerant, liquid refrigerant can be collected in the accumulator, which is then available for the subsequent supply to the warmer first evaporator without necessarily requiring a separate pumping process. This saves energy for compressor operation and avoids the other disadvantages of the pumping process, such as an unwanted, significant drop in evaporation pressure in the evaporators during pumping.

[0013] By providing multiple connections on the receiver, which connect the individual throttles leading to the respective evaporator, refrigerant can be easily allocated from the receiver to the respective evaporator as needed. In particular, rapid filling and a higher filling level of the first evaporator are facilitated, which improves the efficiency of the refrigerant circuit when supplying the first evaporator. Because a relatively uniform filling of the first evaporator is achieved quickly, frost also forms more evenly on the evaporator, increasing operational reliability.When filling the first evaporator with the refrigerant coming from the receiver, a two-phase mixture of liquid and gaseous refrigerant is usually formed, whereby the proportion of gaseous refrigerant is usually significantly larger than that of the liquid refrigerant, for example, the proportion of liquid refrigerant in the volume can be 10 percent or less, so that the line volume of the first evaporator is filled quickly.

[0014] A further advantage of the multi-port receiver in combination with the valve arrangement is that filling the first evaporator with refrigerant is achieved more reliably even when ambient temperatures change.

[0015] According to some embodiments, it can be provided that the second connection is located above the first connection with respect to the direction of gravity. For example, the collector can have a container with a base and an inlet region, wherein the inlet region forms an inlet connection connected to the outlet of the evaporator, through which inlet connection refrigerant can be supplied to the collector. The first connection can be arranged, for example, in the region of the base. The second connection can be positioned in the inlet region. The container defines a collecting volume for receiving the liquid refrigerant, and the base is part of the container. The inlet region can be formed, for example, in a cover of the container and / or by a line section that is connected to a container.By arranging the second connection above the first connection, it is easily ensured that the first evaporator is quickly and reliably filled with the refrigerant in the receiver after the valve arrangement has been switched in such a way that the first evaporator is fluidly connected to the first connection. Optionally, the first connection can be arranged at the lowest point of the receiver in relation to the direction of gravity. By arranging the first connection at the bottom and the second connection at the top, the refrigerant is collected immediately in front of the valve arrangement, which is arranged between the receiver and the respective throttle. As a result, the effect of gravity facilitates rapid filling of the first evaporator using the refrigerant in the receiver through the first connection.

[0016] According to some embodiments, it can be provided that an outlet of the first evaporator and an outlet of the second evaporator are each connected to a suction line, wherein a check valve is integrated between the outlet of the second evaporator and the suction line in such a way that it only allows an outflow of refrigerant from the second evaporator into the suction line and blocks an inflow of refrigerant from the suction line into the second evaporator. Accordingly, the outlet of the first evaporator is not connected to the inlet of the second evaporator, but rather the outlets of both the first and the second evaporator are each connected to the suction line, which in turn is connected to a suction connection of the compressor. During operation of the warmer first evaporator, no refrigerant flows back into the colder, second evaporator due to the check valve.This allows the first evaporator to operate at a higher evaporation pressure than the second evaporator, which has a positive impact on energy efficiency. On the other hand, while the second evaporator is being supplied with refrigerant, the first evaporator is essentially completely emptied, which is why it must first be refilled to cool the first storage compartment. In this situation, the receiver with several spatially separated outlets advantageously facilitates rapid filling of the first evaporator, as already described above.

[0017] According to some embodiments, a maximum fill volume of the collector, which is defined by a position of the second outlet of the collector, since this outlet acts as an overflow, can be dimensioned such that the maximum fill volume is smaller than a line volume of the first evaporator. This reliably prevents overflow of the first evaporator and further increases the operational reliability of the refrigerant circuit. For example, the maximum fill volume of the collector can be in a range between 5 percent and 50 percent of the line volume of the first evaporator.

[0018] According to some embodiments, the refrigerant circuit can have a control device that is signal-connected to the compressor and the valve arrangement and is configured to operate the compressor and, during operation of the compressor, to switch the valve arrangement such that optionally the first evaporator is connected to the first connection or the second evaporator is connected to the second connection. The control device can thus generally be configured to switch the valve arrangement and to activate and deactivate the compressor. Preferably, either only the first evaporator or only the second evaporator is supplied with refrigerant. In general, the control device can be configured to operate the refrigerant circuit, when used in a refrigeration device according to the second aspect of the invention, according to the method according to the third aspect of the invention.

[0019] According to some embodiments, it can be provided that the control device is configured to switch the valve arrangement such that, during operation of the compressor, before the first evaporator is connected to the first connection of the collector, the second evaporator is first connected to the second connection for a predetermined period of time in order to fill the collector with liquid refrigerant. This can result in even faster filling of the first evaporator. According to some embodiments of the method, it can accordingly be provided that, after a predetermined time has elapsed, during which the second evaporator is supplied with refrigerant, the valve arrangement is switched such that the first evaporator is supplied with refrigerant and the supply of refrigerant to the second evaporator is interrupted.

[0020] According to some embodiments, the collector may be partially filled with a desiccant to remove water from the refrigerant. This can further simplify the design of the refrigerant circuit by reducing the number of parts and connection points.

[0021] According to some embodiments, the valve arrangement may comprise a first valve arranged between the first port of the collector and the first throttle, and a second valve arranged between the second port of the collector and the second throttle.

[0022] According to some embodiments, it can be provided that the valve arrangement comprises a multi-way valve to which both the first and the second connection of the collector as well as the first and the second throttle are connected.

[0023] According to some embodiments, the condenser arrangement can have a frame heater and a condenser connected in series with the frame heater. The condenser can be, for example, a finned condenser or an external wall condenser. The frame heater is formed by a line section which is connected to a pressure connection of the compressor and, when the refrigerant circuit is used in the refrigeration appliance according to the second aspect of the invention, extends at least in sections along an access opening through which the second storage compartment is accessible. The frame heater helps to prevent condensate formation in the region of the access opening. A condenser arrangement with a frame heater and condenser has a relatively long line length which the refrigerant must travel from the compressor to the outlet of the condenser.The use of the collector according to the invention helps to ensure that even in such configurations of the condenser arrangement, at the beginning of the supply of the first evaporator, liquid refrigerant immediately flows from the collector into the first evaporator and thus the filling of the first evaporator is accelerated despite the long line length.

[0024] According to some embodiments, it may be provided that the first storage compartment is a refrigeration compartment designed to operate at a temperature in a range between 0°C and +12°C, and the second storage compartment is a freezer compartment designed to operate at a temperature in a range between -5°C and -25°C.

[0025] The features and advantages disclosed herein in connection with one aspect of the invention are also disclosed for the other aspect and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The invention is explained below with reference to the figures of the drawings. The figures show: Fig. 1 a simplified, schematic sectional view of a refrigeration device according to an embodiment of the invention; Fig. 2 a simplified, schematic hydraulic circuit diagram of a refrigerant circuit according to an embodiment of the invention; Fig. 3 a flowchart of a method according to an embodiment of the invention.

[0027] In the figures, the same reference symbols denote identical or functionally identical components, unless otherwise stated. DETAILED DESCRIPTION OF EMBODIMENTS

[0028] Fig. Figure 1 shows an example of a household refrigeration appliance 200 in the form of a refrigerator-freezer combination. However, the invention is not limited to this, but can generally be used with refrigeration appliances 200 with multiple storage compartments.

[0029] As in Fig. 1, the refrigeration device 200 has a first storage compartment 221, a second storage compartment 222 and a refrigerant circuit 100.

[0030] The first storage compartment 221 and the second storage compartment 222 can be formed, for example, in a body 210 of the refrigeration device 200. Each of the storage compartments 221, 222 can have its own access opening 221A, 222A, which can be closed by a respective door 211, 212. The doors 211, 212 can, for example, be hinged to the body 210 in order to be pivotable between a closed position, in which they cover the respective access opening 221A, 222A, and an open position, in which they expose the respective access opening 221A, 222A.

[0031] The first storage compartment 221 may, for example, be a refrigerated compartment designed for operation at a temperature in a range between 0°C and +12°C. The second storage compartment 222 may, for example, be a freezer compartment designed for operation at a temperature in a range between -5°C and -25°C. Generally, the first storage compartment 221 is designed for operation at a first temperature, and the second storage compartment 222 is designed for operation at a second temperature that is lower than the first temperature.

[0032] The refrigerant circuit 100 is in Fig. 1 shown purely schematically. Fig. 2 shows a hydraulic circuit diagram of the refrigerant circuit 100.

[0033] As in the Fig. 1 and Fig. 2, the refrigerant circuit 100 comprises a first evaporator 1, a second evaporator 2, a condenser arrangement 3, a collector 4, a first throttle 5A, a second throttle 5B, a compressor 6, and a valve arrangement 7. Optionally, the refrigerant circuit 100 may also comprise a control device 8, as shown in Fig. 1 shown as an example.

[0034] The first evaporator 1 is thermally coupled to the first storage compartment 221. For example, the first evaporator 1 can be arranged in an evaporator chamber (not shown) that is fluidly connected to the first storage compartment 221, wherein air can be circulated between the first storage compartment 221 and the evaporator chamber by means of a fan (not shown) in order to dissipate heat from the first storage compartment 221 to the refrigerant located in the evaporator 1. Alternatively, it is also conceivable for the first evaporator 1 to be in thermally conductive contact with an outer side of one of the walls that define the first storage compartment 221.

[0035] The second evaporator 2 is thermally coupled to the second storage compartment 222. For example, the second evaporator 2 can be arranged in an evaporator chamber (not shown) that is fluidly connected to the second storage compartment 222, wherein air can be circulated between the second storage compartment 222 and the evaporator chamber by means of a fan (not shown) in order to dissipate heat from the second storage compartment 222 to the refrigerant located in the evaporator 2. Alternatively, it is also conceivable for the second evaporator 2 to be in thermally conductive contact with an outer side of one of the walls that border the second storage compartment 222 or is arranged in the second storage compartment 222. The second evaporator 2 is generally designed to evaporate refrigerant at a temperature that is lower than a temperature at which the refrigerant evaporates in the first evaporator 1.

[0036] The condenser assembly 3 is thermally coupled to the environment to dissipate heat to the environment by condensing refrigerant. Fig. 2, the condenser assembly 3 is shown only schematically as a single condenser 32. Optionally, the condenser assembly 3 can comprise a condenser 32 and a frame heater 31, as shown in Fig. 1 is shown schematically.

[0037] The condenser 32 can, for example, be an external wall condenser arranged on an outer wall of the body 210. Alternatively, the condenser 32 can also be a compact condenser arranged together with the compressor 6 in a machine room (not shown), which is actively supplied with an air flow by means of a fan (not shown).

[0038] The optional frame heating 31 can be installed as shown in Fig. 1, shown only schematically, is formed by a conduit section that extends at least partially along the access opening 222A of the second storage compartment 222 or at least partially surrounds it. The condenser 32 and the frame heater 31 are connected in series.

[0039] The first evaporator 1 and the second evaporator 2 are connected in parallel to an outlet of the condenser arrangement 3, e.g. to an outlet of the condenser 32, as in Fig. 1 is shown as an example. This means that each of the evaporators 1, 2 can be supplied with refrigerant coming from the condenser arrangement 3 independently of the other evaporator 2, 1.

[0040] The first throttle 5A is connected upstream of the first evaporator 1. As shown in the Fig. 1 and Fig. 2, the first throttle 5A, which may be designed as a capillary tube, is connected to an inlet of the first evaporator 1.

[0041] The second throttle 5B is connected upstream of the second evaporator 2. As shown in the Fig. 1 and Fig. 2, the second throttle 5B, which may be designed as a capillary tube, is connected to an inlet of the second evaporator 2.

[0042] The first and / or the second throttle 5A, 5B can be in thermal contact with the suction line 65 at least in sections in order to form a so-called suction-throttle heat exchanger.

[0043] The collector 4 is in the Fig. 1 and Fig. 2 is shown only schematically and is connected to the outlet of the condenser arrangement 3 and is designed to collect liquid refrigerant coming from the condenser arrangement 3. For example, the collector 4 can have a container with a base and a lid arranged opposite the base. An inlet region of the collector 4 can be formed in the region of the lid, e.g. as an opening in the container or as a line section connected to the container. The base can be arranged at the bottom with respect to the direction of gravity. The inlet region can accordingly be arranged at the top with respect to the direction of gravity.

[0044] In general, the collector 4 has a first connection 41 and a second connection 42, which are arranged spatially separated from one another. In particular, the second connection 42 can be arranged above the first connection 41 with respect to the direction of gravity. For example, the first connection 41 can be formed in the bottom of the container, while the second connection 42 can be formed in the inlet region of the collector 4, as shown in the Fig. 1 and Fig. 2 is shown as an example. The collector 4 can optionally be partially filled with a desiccant to remove water from the refrigerant collecting in the collector 4.

[0045] The first throttle 5A connects the first port 41 of the collector 4 to the inlet of the first evaporator 1. The second throttle 5B connects the second port 42 to the inlet of the second evaporator 2.

[0046] The valve assembly 7 is arranged between the collector 4 and the throttles 5A, 5B. As shown in the Fig. 1 and Fig. 2 purely by way of example, the valve arrangement 7 can have a first valve 71, which is arranged between the first connection 41 of the collector 4 and the first throttle 5A, and a second valve 72, which is arranged between the second connection 42 of the collector 4 and the second throttle 5B. The first and the second valve 71, 72 can each be switched between an open state and a closed state in order to establish a fluidically conductive connection between the collector 4 and the respective evaporator 1, 2 in the open state and to separate them in the closed state. Alternatively, the valve arrangement 7 can also have a multi-way valve to which both the first and the second connection 41, 42 of the collector 4 and the first and the second throttle 5A, 5B are connected.The multi-way valve can be switchable in such a way as to alternately establish and break a fluidic connection between the first port 41 and the first throttle 5A, and to establish or break a fluidic connection between the second port 42 and the second throttle 5B. In general, the valve arrangement 7 is thus designed as a switchable valve arrangement. When the valve arrangement 7 establishes a fluidic connection between the collector 4 and the respective evaporator 1, 2, a refrigerant flow is enabled between the respective outlet 41, 42 of the collector 4 and the respective evaporator 1, 2.

[0047] As in the Fig. 1 and Fig. 2, an outlet of the first evaporator 1 and an outlet of the second evaporator 2 are each connected to a suction line 65. The suction line 65 is connected to a suction connection 61 of the compressor 6. A pressure connection 62 of the compressor 6 is connected to an inlet of the condenser arrangement 3, e.g., to an inlet of the frame heater 31, as shown in Fig. 1 purely by way of example. By means of the compressor 6, the refrigerant can thus be circulated between the condenser arrangement 3 and the evaporators 1, 2, so that it absorbs heat from the respective storage compartment 221, 222 while evaporating in the respective evaporator 1, 2 and releases it to the environment in the condenser arrangement 3 while condensing. Depending on the switching position of the valve arrangement 7, in particular in a switching position in which the fluidically conductive connection between the first connection 41 of the collector 4 and the first evaporator 1 is separated by the valve arrangement 7, e.g. when the first valve 71 is closed, liquid refrigerant coming from the condenser arrangement 3 can collect in the collector 4.

[0048] As purely exemplary and merely schematically in Fig. 2, a check valve 67 can be arranged between the outlet of the second evaporator 2 and the suction line 65. The check valve 67 is integrated or mounted between the outlet of the second evaporator 2 and the suction line 65 in such a way that it only allows an outflow of refrigerant from the second evaporator 2 into the suction line 65 and blocks an inflow of refrigerant from the suction line 65 into the second evaporator 2. Thus, when the valve arrangement 7 connects the inlet of the first evaporator 1 to the first connection 41 of the collector 4, for example when the first valve 71 is open and the second valve 72 is closed, the evaporator 1 can be supplied with refrigerant at a higher vapor pressure than the second evaporator 2, without refrigerant flowing from the suction line 65 into the second evaporator 2.

[0049] The refrigerant circuit 100 described above allows the first evaporator 1 and the second evaporator 2 to be alternately supplied with refrigerant in order to extract heat from the respective storage compartment 221, 222. If in the example the Fig. 1 and Fig. 2, the first valve 71 is open and the second valve 72 is closed, only the first evaporator 1 is supplied with refrigerant. If the second valve 72 is open and the first valve 71 is closed, only the second evaporator 1 is supplied with refrigerant. In this case, the suction of the refrigerant from the second evaporator 2 by the compressor 6 results in the first evaporator 1 being essentially emptied. In principle, a simultaneous supply of both evaporators 1, 2 with refrigerant is also conceivable. If the valve arrangement 7 is switched in such a way that the fluidically conductive connection between the first connection 41 of the collector 4 and the first evaporator 1 is separated by the valve arrangement 7, e.g. when the first valve 71 is closed, and only the second evaporator 2 is connected to the collector 4, e.g. when the second valve 72 is open, liquid refrigerant coming from the condenser arrangement 3 collects in the collector 4.This retention of refrigerant can be further facilitated if the second connection 42 of the collector 4 is located above the first connection 41 with respect to the direction of gravity, as shown in Figures . Fig. 1 and Fig. 2 as an example. As soon as the fill level of the collector 4 is high enough for refrigerant to flow out of the second connection 42, the second evaporator 2 is supplied. If, after the supply to the second evaporator 2 has ended, the valve arrangement 7 is switched such that the fluidic connection between the first connection 41 of the collector 4 and the first evaporator 1 is opened by the valve arrangement 7, e.g. when the first valve 71 is open, and the second evaporator 2 is separated from the collector 4, e.g. when the second valve 72 is closed, refrigerant flows out of the bottom of the collector 4 through the first throttle 5A into the first evaporator 1. In this way, a quick and efficient filling of the first evaporator 1 can be achieved, which has a beneficial effect on the efficiency of the refrigerant circuit 100.Furthermore, the operational reliability of the refrigerant circuit 100 is increased by the receiver 4, as uneven frosting of the first evaporator 1 is counteracted and the filling of the first evaporator 1 can be largely independent of temperature. Since the receiver 4 is preferably completely emptied, the dosing of the refrigerant at the beginning of the supply to the first evaporator 1 is also improved.

[0050] The volume of the collector 4 can, for example, be dimensioned such that the liquid refrigerant that can be collected therein is sufficient for efficient filling of the first evaporator 1. For example, the collector 4 can have a volume that lies in a range between 5 percent and 50 percent of an internal volume or line volume of the first evaporator 1. In general, a maximum filling volume of the collector 4 can be smaller than the line volume of the first evaporator 1.

[0051] The control device 8 may, in particular, be an electronic control device. For example, the control device 8 may comprise a non-volatile data storage medium (not shown), such as an EEPROM memory, a flash memory, an SD memory, or the like, and a processor (not shown), such as a CPU, an FPGA, an ASIC, or the like. The storage medium is readable by the processor and may store software that is executable by the processor. The control device 8 may, for example, be configured to generate control signals based on input signals and to output the control signals. As shown in Fig. 1, the control device 8 can be connected to the valve arrangement 7 and the compressor 6 in a signal-conducting manner, e.g., via a bus system or a wireless data connection. The control device 8 can be designed to output control signals to the compressor 6 in order to operate it, e.g., to activate and deactivate it. Furthermore, the control device 8 can be designed to output control signals to the valve arrangement 7 in order to switch it, e.g., to switch the first valve 71 and the second valve 72 between the open and closed states.

[0052] The control device 8 can in particular be designed to operate the refrigeration device 200 with the refrigerant circuit 100 according to a method M, the sequence of which is described in Fig. 3 is shown schematically.

[0053] In step M1, the compressor 6 is operated. For example, the control device 8 can output a control signal to the compressor 6 in order to activate it and circulate refrigerant in the refrigerant circuit 100.

[0054] In step M2, the valve arrangement 7 is switched such that the second evaporator 2 is supplied with refrigerant to extract heat from the freezer compartment 222. At the same time, the fluidic connection between the first connection 41 of the collector 4 and the first evaporator 1 is preferably severed, e.g., by closing the first valve 71. The control device 8 can output corresponding control signals to the valve arrangement 7 for switching it. As already explained above, with the described switching of the valve arrangement, the collector 4 is filled with liquid refrigerant.

[0055] In step M3, the valve arrangement 7 is switched in such a way that the first evaporator 1 is supplied with refrigerant, e.g. by opening the first valve 71. As a result, immediately after the valve arrangement 7 is switched, the first evaporator 1 is supplied with liquid refrigerant from the collector 4 and is thus quickly filled. In this case, it can be provided that the collector 4 is completely emptied. When the first evaporator 1 is filled with the refrigerant coming from the collector 4, a two-phase mixture of liquid and gaseous refrigerant is usually formed, wherein the proportion of gaseous refrigerant is generally significantly greater than that of the liquid refrigerant, so that the line volume of the first evaporator 1 is quickly filled. After switching in step M3, the first evaporator 1 is thus supplied with refrigerant in order to extract heat from the first storage compartment 221.

[0056] Steps M2 and M3 can, for example, be coordinated such that the valve arrangement 7 is switched so that the first evaporator 1 is supplied with refrigerant and the supply of refrigerant to the second evaporator 2 is interrupted only after a predetermined time has elapsed, during which the second evaporator 2 is supplied with refrigerant. Before the first evaporator 1 is connected to the first connection 41, the second evaporator 2 can thus first be connected to the second connection 42 for a predetermined period of time in order to fill the collector 4 with liquid refrigerant. The predetermined period of time can be selected to achieve a desired fill level of the collector 4.

[0057] Although the present invention has been explained above using exemplary embodiments, it is not limited thereto, but can be modified in many ways. For example, the refrigerant circuit 100 can also have more than two evaporators 1, 2, whose inlets are connected in parallel to the outlet of the condenser arrangement 3. In this case, more than two connections 41, 42 can also be provided on the collector 4, wherein each connection is connected to at least one evaporator via at least one throttle. The evaporators can each be designed for operation at different temperatures. The evaporator intended for operation at the highest temperature is preferably connected to a connection of the collector that is lowest in relation to the direction of gravity. Combinations of the above exemplary embodiments are also conceivable. REFERENCE SYMBOL 1 first evaporator 2 second evaporator 3 Condenser arrangement 4 collectors 5A first choke 5B second throttle 6 compressors 7 Valve arrangement 8 Control device 31 frame heating 32 condensers 41 first connection of the collector 42 second connection of the collector 61 Compressor suction connection 62 Compressor pressure connection 65 Suction line 67 Check valve 100 Refrigerant circuit 200 refrigeration unit 210 Corpus 211 Door of the first storage compartment 212 Door of the second storage compartment 221 first storage compartment 221A Access opening of the first storage compartment 222 second storage compartment 222A Access opening of the second storage compartment M procedure M1-M3 process steps QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 5 465 591 A

[0004]

Claims

[1] Refrigerant circuit (100) for a refrigeration device (200), in particular for a household refrigeration device, comprising: a condenser arrangement (3); a first evaporator (1) for cooling a first storage compartment (221) at a first temperature; a second evaporator (2) for cooling a second storage compartment (222) at a second temperature which is lower than the first temperature, the first evaporator (1) and the second evaporator (2) being connected in parallel to an outlet of the condenser (3); a first throttle (5A) connected upstream of the first evaporator (1); a second throttle (5B) connected upstream of the second evaporator (2); a collector (4) connected to the outlet of the condenser arrangement (3) and designed to collect liquid refrigerant coming from the condenser arrangement (3); a switchable valve arrangement (7) arranged between the collector (4) and the throttles (5A, 5B); and a compressor (6) for circulating the refrigerant between the respective evaporator (1, 2) and the condenser arrangement (3); characterized by , that the collector (4) has a first connection (41) connected to the first throttle (5A) and a second connection (42) connected to the second throttle (5B), and the valve arrangement (7) is designed to alternately establish and separate a fluidically conductive connection between the first connection (41) and the first throttle (5A), and to establish or separate a fluidically conductive connection between the second connection (42) and the second throttle (5B). [2] Refrigerant circuit (100) according to claim 1, wherein the second connection (42) is located above the first connection (41) with respect to the direction of gravity (G). [3] Refrigerant circuit (100) according to claim 1 or 2, wherein an outlet of the first evaporator (1) and an outlet of the second evaporator (2) are each connected to a suction line (65), and wherein a check valve (67) is integrated between the outlet of the second evaporator (2) and the suction line (65) in such a way that it only allows an outflow of refrigerant from the second evaporator (2) into the suction line (65) and blocks an inflow of refrigerant from the suction line (65) into the second evaporator (2). [4] Refrigerant circuit (100) according to one of the preceding claims, additionally comprising: a control device (9) which is signal-connected to the compressor (6) and the valve arrangement (7) and is designed to operate the compressor (6) and, during operation of the compressor (6), to switch the valve arrangement (7) such that optionally the first evaporator (1) is connected to the first connection (41) or the second evaporator (2) is connected to the second connection (42). [5] Refrigerant circuit (100) according to claim 4, wherein the control device (9) is configured to switch the valve arrangement (7) such that during operation of the compressor (6), before connecting the first evaporator (1) to the first connection (41), the second evaporator (2) is first connected to the second connection (42) for a predetermined period of time in order to fill the collector (4) with liquid refrigerant. [6] Refrigerant circuit (100) according to one of the preceding claims, wherein the collector (4) is partially filled with a desiccant to remove water from the refrigerant. [7] Refrigerant circuit (100) according to one of the preceding claims, wherein the valve arrangement (7) comprises a first valve (71) arranged between the first connection (41) of the collector (4) and the first throttle (5A), and a second valve (72) arranged between the second connection (42) of the collector (4) and the second throttle (5B), or wherein the valve arrangement (7) comprises a multi-way valve to which both the first and the second connection (41, 42) of the collector (4) and the first and the second throttle (5A, 5B) are connected. [8] Refrigerant circuit (100) according to one of the preceding claims, wherein the condenser arrangement (3) has a frame heater (31) and a condenser (32) connected in series therewith. [9] Refrigeration appliance (200), in particular household refrigeration appliance, comprising: a first storage compartment (221) for operation at a first temperature; a second storage compartment (222) for operation at a second temperature which is less than the first temperature; and a refrigerant circuit (100) according to one of the preceding claims, wherein the first evaporator (1) is thermally coupled to the first storage compartment (221), and the second evaporator (2) is thermally coupled to the second storage compartment (222). [10] Refrigeration appliance (200) according to claim 9, wherein the first storage compartment (221) is a refrigeration compartment designed to operate at a temperature in a range between 0°C and +12°C, and the second storage compartment (222) is a freezer compartment designed to operate at a temperature in a range between -5°C and -25°C. [11] Method (M) for operating a refrigeration device (200) according to claim 9 or 10, comprising: Operating (M1) the compressor (6); Switching (M2) the valve arrangement (7) such that the second evaporator (2) is supplied with refrigerant in order to extract heat from the freezer compartment (222) and to fill the collector (4) with liquid refrigerant; Switching (M3) the valve arrangement (7) such that the first evaporator (1) is supplied with refrigerant, wherein the first evaporator (1) is filled with refrigerant from the collector (4) immediately after switching (M3). [12] Method (M) according to claim 11, wherein the valve arrangement (7) is switched after a predetermined time in which the second evaporator (2) is supplied with refrigerant, such that the first evaporator (1) is supplied with refrigerant and the supply of the second evaporator (2) with refrigerant is interrupted.

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