REFRIGERATOR APPLIANCE DUAL FLOW REFRIGERANT DECOUPLING

Abstract

A method of operating a refrigerator appliance includes directing a flow of liquid refrigerant through a sealed system of the refrigerator appliance from a condenser of the sealed system to a fresh food evaporator of the sealed system. the method also includes warming a freezer evaporator of the sealed system while directing the flow of liquid refrigerant through the sealed system to the fresh food evaporator.

Claims

1. A method of operating a refrigerator appliance, comprising: directing a flow of liquid refrigerant through a sealed system of the refrigerator appliance from a condenser of the sealed system to a fresh food evaporator of the sealed system; and warming a freezer evaporator of the sealed system while directing the flow of liquid refrigerant through the sealed system to the fresh food evaporator.

2. The method of claim 1, further comprising monitoring a temperature of a suction line of the sealed system and comparing the monitored temperature of the suction line to a minimum temperature.

3. The method of claim 1, wherein warming the freezer evaporator comprises operating an ice box fan, whereby air is circulated between the freezer evaporator and an ice box of the refrigerator appliance, while directing the flow of liquid refrigerant through the sealed system to the fresh food evaporator.

4. The method of claim 3, wherein the air circulated between the freezer evaporator and the ice box does not flow through a freezer compartment of the refrigerator appliance.

5. The method of claim 3, wherein the ice box fan is operated at a speed, and wherein the speed is selected such that an ice box target temperature is reached approximately simultaneously with a fresh food target temperature.

6. The method of claim 1, wherein warming the freezer evaporator comprises operating a freezer fan, whereby air is circulated between the freezer evaporator and a freezer compartment of the refrigerator appliance, while directing the flow of liquid refrigerant through the sealed system to the fresh food evaporator.

7. The method of claim 6, further comprising, after operating the freezer fan while directing the flow of liquid refrigerant through the sealed system to the fresh food evaporator, deactivating the freezer fan when a temperature of the freezer evaporator is approximately equal to a temperature of a freezer compartment of the refrigerator appliance.

8. The method of claim 7, wherein warming the freezer evaporator further comprises operating an ice box fan, whereby air is circulated between the freezer evaporator and an ice box of the refrigerator appliance, while directing the flow of liquid refrigerant through the sealed system to the fresh food evaporator.

9. The method of claim 8, wherein the ice box fan is operated to circulate air between the freezer evaporator and the ice box after deactivating the freezer fan.

10. The method of claim 1, wherein warming the freezer evaporator comprises raising a temperature of the freezer evaporator above a temperature of a freezer compartment of the refrigerator appliance.

11. A refrigerator appliance, comprising: a sealed system comprising a condenser, a fresh food evaporator, and a freezer evaporator; and a controller in operative communication with the sealed system, the controller configured for: directing a flow of liquid refrigerant through the sealed system from the condenser to the fresh food evaporator of the sealed system; and warming the freezer evaporator while directing the flow of liquid refrigerant through the sealed system to the fresh food evaporator.

12. The refrigerator appliance of claim 11, wherein the controller is further configured for monitoring a temperature of a suction line of the sealed system and comparing the monitored temperature of the suction line to a minimum temperature.

13. The refrigerator appliance of claim 11, wherein warming the freezer evaporator comprises operating an ice box fan, whereby air is circulated between the freezer evaporator and an ice box of the refrigerator appliance, while directing the flow of liquid refrigerant through the sealed system to the fresh food evaporator.

14. The refrigerator appliance of claim 13, wherein the air circulated between the freezer evaporator and the ice box does not flow through a freezer compartment of the refrigerator appliance.

15. The refrigerator appliance of claim 13, wherein the ice box fan is operated at a speed, and wherein the speed is selected such that an ice box target temperature is reached approximately simultaneously with a fresh food target temperature.

16. The refrigerator appliance of claim 11, wherein warming the freezer evaporator comprises operating a freezer fan, whereby air is circulated between the freezer evaporator and a freezer compartment of the refrigerator appliance, while directing the flow of liquid refrigerant through the sealed system to the fresh food evaporator.

17. The refrigerator appliance of claim 16, wherein the controller is further configured for, after operating the freezer fan while directing the flow of liquid refrigerant through the sealed system to the fresh food evaporator, deactivating the freezer fan when a temperature of the freezer evaporator is approximately equal to a temperature of a freezer compartment of the refrigerator appliance.

18. The refrigerator appliance of claim 17, wherein warming the freezer evaporator further comprises operating an ice box fan, whereby air is circulated between the freezer evaporator and an ice box of the refrigerator appliance, while directing the flow of liquid refrigerant through the sealed system to the fresh food evaporator.

19. The refrigerator appliance of claim 18, wherein the ice box fan is operated to circulate air between the freezer evaporator and the ice box after deactivating the freezer fan.

20. The refrigerator appliance of claim 11, wherein warming the freezer evaporator comprises raising a temperature of the freezer evaporator above a temperature of a freezer compartment of the refrigerator appliance.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.

[0010] FIG. 1 provides a perspective view of a refrigerator appliance according to an exemplary embodiment of the present subject matter.

[0011] FIG. 2 provides a perspective view of the exemplary refrigerator appliance of FIG. 1, with the doors of the fresh food chamber shown in an open position.

[0012] FIG. 3 provides an interior perspective view of a dispenser door of the exemplary refrigerator appliance of FIG. 1.

[0013] FIG. 4 provides a schematic view of an exemplary sealed system according to one or more embodiments of the present disclosure, which may be incorporated into a refrigerator appliance such as the refrigerator appliance of FIG. 1.

[0014] FIG. 5 provides a schematic view of another exemplary sealed system according to one or more embodiments of the present disclosure, which may be incorporated into a refrigerator appliance such as the refrigerator appliance of FIG. 1.

[0015] FIG. 6 provides a flow diagram of an exemplary method of operating a refrigerator appliance according to one or more embodiments of the present disclosure.

[0016] FIG. 7 provides a flow diagram of another exemplary method of operating a refrigerator appliance according to one or more embodiments of the present disclosure.

[0017] The use of the same similar reference numbers in the figures denotes the same or similar features unless the context indicates otherwise.

DETAILED DESCRIPTION

[0018] Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

[0019] As used herein, terms of approximation, such as generally, or about include values within ten percent greater or less than the stated value. When used in the context of an angle or direction, such terms include within ten degrees greater or less than the stated angle or direction. For example, generally vertical includes directions within ten degrees of vertical in any direction, e.g., clockwise or counterclockwise. As used herein, the terms first, second, and third may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components.

[0020] Furthermore, the skilled artisan will recognize the interchangeability of various features from different embodiments. Similarly, the various method steps and features described, as well as other known equivalents for each such methods and features, can be mixed and matched by one of ordinary skill in this art to construct additional systems and techniques in accordance with principles of this disclosure. Of course, it is to be understood that not necessarily all such objects or advantages described above may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that the systems and techniques described herein may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

[0021] FIG. 1 provides a perspective view of a refrigerator appliance 100 according to an exemplary embodiment of the present subject matter. Refrigerator appliance 100 includes a cabinet or housing 102 that extends between a top 104 and a bottom 106 along a vertical direction V, between a first side 108 and a second side 110 along a lateral direction L, and between a front side 112 and a rear side 114 along a transverse direction T. Each of the vertical direction V, lateral direction L, and transverse direction T are mutually perpendicular to one another.

[0022] Housing 102 defines chilled chambers for receipt of food items for storage. In particular, housing 102 defines fresh food chamber 122 positioned at or adjacent top 104 of housing 102 and a freezer chamber 124 arranged at or adjacent bottom 106 of housing 102. As such, refrigerator appliance 100 is generally referred to as a bottom mount refrigerator. It is recognized, however, that the benefits of the present disclosure apply to other types and styles of refrigerator appliances. Consequently, the description set forth herein is for illustrative purposes only and is not intended to be limiting in any aspect to any particular refrigerator configuration.

[0023] Refrigerator doors 128 are rotatably hinged to an edge of housing 102 for selectively accessing fresh food chamber 122. In addition, a freezer door 130 is arranged below refrigerator doors 128 for selectively accessing freezer chamber 124. Freezer door 130 is coupled to a freezer drawer (not shown) slidably mounted within freezer chamber 124. Refrigerator doors 128 and freezer door 130 are shown in the closed configuration in FIG. 1. One skilled in the art will appreciate that other chamber and door configurations are possible and within the scope of the present invention.

[0024] FIG. 2 provides a perspective view of refrigerator appliance 100 shown with refrigerator doors 128 in the open position. As shown in FIG. 2, various storage components are mounted within fresh food chamber 122 to facilitate storage of food items therein as will be understood by those skilled in the art. In particular, the storage components may include bins 134 and shelves 136. Each of these storage components are configured for receipt of food items (e.g., beverages and/or solid food items, etc.) and may assist with organizing such food items. As illustrated, bins 134 may be mounted on refrigerator doors 128 or may slide into a receiving space in fresh food chamber 122. It should be appreciated that the illustrated storage components are used only for the purpose of explanation and that other storage components may be used and may have different sizes, shapes, and configurations.

[0025] Referring now generally to FIG. 1, a dispensing assembly 140 will be described according to exemplary embodiments of the present subject matter. Dispensing assembly 140 is generally configured for dispensing liquid water and/or ice. Although an exemplary dispensing assembly 140 is illustrated and described herein, it should be appreciated that variations and modifications may be made to dispensing assembly 140 while remaining within the present subject matter.

[0026] Dispensing assembly 140 and its various components may be positioned at least in part within a dispenser recess 142 defined on one of refrigerator doors 128. In this regard, dispenser recess 142 is defined on a front side 112 of refrigerator appliance 100 such that a user may operate dispensing assembly 140 without opening refrigerator door 128. In addition, dispenser recess 142 is positioned at a predetermined elevation convenient for a user to access ice and enabling the user to access ice without the need to bend over. In the exemplary embodiment, dispenser recess 142 is positioned at a level that approximates the chest level of a user.

[0027] Dispensing assembly 140 includes an ice dispenser 144 including a discharging outlet 146 for discharging ice from dispensing assembly 140. An actuating mechanism 148, shown as a paddle, is mounted below discharging outlet 146 for operating ice or water dispenser 144. In alternative exemplary embodiments, any suitable actuating mechanism may be used to operate ice dispenser 144. For example, ice dispenser 144 may include a sensor (such as an ultrasonic sensor) or a button rather than the paddle. Discharging outlet 146 and actuating mechanism 148 are an external part of ice dispenser 144 and are mounted in dispenser recess 142.

[0028] By contrast, inside refrigerator appliance 100, refrigerator door 128 may define an ice box 150 (FIGS. 2 and 3) housing an ice making assembly (not shown) configured to supply ice to dispenser recess 142. In this regard, for example, ice box 150 may define an ice making chamber 154 for housing an ice making assembly and a dispensing mechanism.

[0029] A control panel 160 is provided for controlling the mode of operation. For example, control panel 160 includes one or more selector inputs 162, such as knobs, buttons, touchscreen interfaces, etc., such as a water dispensing button and an ice-dispensing button, for selecting a desired mode of operation such as crushed or non-crushed ice. In addition, inputs 162 may be used to specify a fill volume or method of operating dispensing assembly 140. In this regard, inputs 162 may be in communication with a processing device or controller 164. Signals generated in controller 164 operate refrigerator appliance 100 and dispensing assembly 140 in response to selector inputs 162. Additionally, a display 166, such as an indicator light or a screen, may be provided on control panel 160. Display 166 may be in communication with controller 164, and may display information in response to signals from controller 164.

[0030] As used herein, processing device or controller may refer to one or more microprocessors or semiconductor devices and is not restricted necessarily to a single element. The processing device can be programmed to operate refrigerator appliance 100 and dispensing assembly 140. The processing device may include, or be associated with, one or more memory elements (e.g., non-transitory storage media). In some such embodiments, the memory elements include electrically erasable, programmable read only memory (EEPROM). Generally, the memory elements can store information accessible to the processing device, including instructions that can be executed by processing device. Optionally, the instructions can be software or any set of instructions and/or data that when executed by the processing device, cause the processing device to perform operations. For example, the instructions may include a software package configured to operate the system to, e.g., execute the exemplary methods described below. In exemplary embodiments, the various method steps as disclosed herein may be performed, e.g., in whole or part, by controller 164 and/or another, separate, dedicated controller.

[0031] Referring now to FIG. 3, an interior perspective view of one of the refrigerator doors 128 and an ice box 150 thereon is provided. Refrigerator appliance 100 includes a sub-compartment 150 defined on refrigerator door 128. As mentioned above, the sub-compartment 150 may be referred to as an ice box. In the illustrated exemplary embodiment, ice box 150 extends into fresh food chamber 122 when refrigerator door 128 is in the closed position. An ice making assembly (not shown) may be positioned within the ice box 150.

[0032] As mentioned above, an access door 170 may be hinged to the inside of the refrigerator door 128. Access door 170 permits selective access to ice box 150. Any manner of suitable latch 172 may be configured with ice box 150 to maintain access door 170 in a closed position. As an example, latch 172 may be actuated by a consumer in order to open access door 170 for providing access into ice box 150. Access door 170 can also assist with insulating ice box 150, e.g., by thermally isolating or insulating ice box 150 from fresh food chamber 122.

[0033] Variations and modifications may be made while remaining within the scope of the present subject matter. Accordingly, the description herein of the ice box 150 on the door 128 of the fresh food chamber 122 is by way of example only. In other example embodiments, the ice box 150 may be stationarily positioned in the fresh food chamber 122, e.g., mounted within the cabinet 102 rather than on the door.

[0034] Referring now to FIGS. 4 and 5, the refrigerator appliance may include a sealed cooling system 60, which is schematically illustrated in FIGS. 4 and 5. For example, the sealed cooling system 60 may be positioned in a mechanical compartment that at least partially contains components for executing a known vapor compression cycle for cooling air. The components include a compressor 64, a heat exchanger or condenser 66, an expansion device 68 and/or 69, and an evaporator 70 and/or 71 connected so as to form a sealed loop and charged with a refrigerant. Each evaporator 70 and 71 is also a type of heat exchanger which transfers heat from air passing over the evaporator to refrigerant flowing through the evaporator thereby causing the refrigerant to vaporize. As such, cooled air is produced and configured to refrigerate at least one chamber, e.g., chambers 122 and 124, of refrigerator appliance 100. The cooled air may be directed to the food storage chambers 122 and 124 by a fan 74 and/or 75. The expansion device(s) 68 and/or 69 may be capillary tubes, e.g., as illustrated in FIGS. 4 and 5, or may be electronic expansion valves, or any other suitable expansion device.

[0035] In particular, the sealed system may also include a switch or valve, such as a three-way valve, 72, which directs the refrigerant from the condenser 66 selectively to one or the other of a freezer evaporator 70 (which is in fluid communication with the freezer compartment 124, whereby the freezer fan 74 is operable to urge cooled air produced at the freezer evaporator 70 to the freezer compartment 124) and a fresh food evaporator 71 (which is in fluid communication with the fresh food compartment 122, whereby the fresh food fan 75 is operable to urge cooled air produced at the fresh food evaporator 71 to the fresh food compartment 122). Thus, depending on the position of the three-way valve 72, refrigerant from the condenser 66 may be directed to first expansion device 68 and freezer evaporator 70 or to second expansion device 69 and fresh food evaporator 71.

[0036] From the selected evaporator 70 or 71 (which is selected based on the position of the three-way valve 72 as mentioned above), vaporized refrigerant flows to compressor 64, which operates to increase the pressure of the refrigerant. This compression of the refrigerant raises its temperature, which is lowered by passing the gaseous refrigerant through condenser 66 where heat exchange with ambient air takes place so as to cool the refrigerant. A fan may be used to pull air across condenser 66, so as to provide forced convection for a more rapid and efficient heat exchange between the refrigerant and the ambient air.

[0037] The selected expansion device 68 or 69 further reduces the pressure of refrigerant leaving condenser 66 before being fed as a liquid to freezer evaporator 70 or fresh food evaporator 71. Collectively, the vapor compression cycle components in a refrigeration circuit, associated fans, and associated compartments are sometimes referred to as a sealed refrigeration system operable to force cold air through refrigeration chambers 122 and 124. The refrigeration systems 60 depicted in FIGS. 4 and 5 are provided by way of example only. It is within the scope of the present invention for other configurations of the refrigeration system to be used as well.

[0038] Referring now to FIG. 4 in particular, in some embodiments, the sealed system 60 may have a parallel configuration, e.g., where the evaporators 70 and 71 are connected in parallel such that the refrigerant flows to one evaporator 70 or 71 and bypasses the other evaporator 70 or 71.

[0039] As illustrated in FIG. 5, in some embodiments, the sealed system 60 may be a hybrid system, e.g., wherein the freezer evaporator 70 is downstream of the fresh food evaporator 71 when the three-way valve 72 directs the refrigerant to the fresh food evaporator 71, and wherein the refrigerant bypasses the fresh food evaporator 71 and flows directly into the first expansion device 68 and freezer evaporator 70 when the three-way valve 72 directs the refrigerant to the freezer evaporator 70.

[0040] Turning now to FIGS. 6 and 7, embodiments of the present disclosure also include methods of operating a refrigerator appliance, such as the refrigerator appliance described above, and which may also be used with other refrigerator appliances in various additional embodiments. Accordingly, reference numbers used in the context of the exemplary refrigerator appliance described above are provided in the discussion of methods 600 and 700 by way of example only and are not intended to limit the method 600 and/or 700 to any particular refrigerator appliance configuration, unless the context clearly indicates otherwise.

[0041] As illustrated at (610) in FIG. 6, an exemplary method 600 may include directing a flow of liquid refrigerant through a sealed system 60 of the refrigerator appliance 100 from a condenser 66 of the sealed system 60 to a fresh food evaporator 71 of the sealed system 60, such as by moving a valve, e.g., three-way valve 72, to a position and configuration in which the refrigerant is directed to the fresh food evaporator 71. Method 600 may further include (620) warming a freezer evaporator 70 of the sealed system 60 while directing the flow of liquid refrigerant through the sealed system 60 to the fresh food evaporator 71.

[0042] Turning now to FIG. 7, another exemplary method 700 of operating a refrigerator appliance may include (710) cooling one of a freezer compartment 124 or a fresh food compartment 122 of the refrigerator appliance 100. For example, such cooling may include producing a flow of cooled air as described above with regard to FIGS. 4 and 5 (e.g., directing a flow of liquid refrigerant to a selected evaporator), and urging such cooled air to the respective compartment from an evaporator associated therewith.

[0043] Method 700 may also include a decision function (720) of deciding or determining whether the freezer 124 and fresh food 122 are satisfied, e.g., where satisfied is used to mean that the compartment has reached a temperature that is equal to, less than, and/or within a tolerance range of a setpoint temperature (the setpoint temperature may also be referred to as a target temperature).

[0044] When both the freezer and the fresh food are satisfied, method 700 may proceed to (722) shutting off the freezer and fresh food, e.g., deactivating the compressor 64 and thereby stopping the flow of refrigerant through the sealed system 60, e.g., such that refrigerant flows to neither of the evaporators. Method 700 may then proceed to (724) and warm the freezer evaporator, e.g., by running the freezer fan 74, until the temperature of the freezer evaporator 70 approaches (e.g., is less than but within a predetermined margin of) the freezer compartment 124 temperature. When the temperature of the freezer evaporator 70 approaches the freezer compartment 124 temperature, the freezer fan 74 may be stopped and the sealed system 60, e.g., compressor 64, maybe deactivated.

[0045] As shown at (730) in FIG. 7, when only the fresh food compartment 122 is satisfied, method 700 may include (732) shutting off the fresh food evaporator 71 and supplying the freezer evaporator 70 (e.g., moving or actuating the valve 72 such that liquid refrigerant from the condenser 66 is directed to the freezer evaporator 70). In such instances, (732) may also include running the fresh food fan 75 as desired, e.g., to manage humidity in the fresh food compartment 122 or until the temperature of the fresh food evaporator 71 approaches the temperature of the fresh food compartment 122, while supplying the freezer evaporator 70.

[0046] As shown at (740) in FIG. 7, when only the freezer compartment 124 is satisfied, method 700 may include (742) shutting off the freezer evaporator 70 and supplying the fresh food evaporator 71, e.g., directing the flow of liquid refrigerant through the sealed system 60 of the refrigerator appliance 100 from the condenser 66 of the sealed system 60 to the fresh food evaporator 71 of the sealed system 60. For example, by moving the three-way valve 72 to a position in which refrigerant flow to the freezer evaporator 70 (at least direct refrigerant flow, i.e., not via the fresh food evaporator 71 first) is obstructed and the refrigerant flow is directed to the fresh food evaporator 71 (such as at least to the fresh food evaporator 70 first, e.g., in hybrid sealed system embodiments, or only to the fresh food evaporator 71 and bypassing the freezer evaporator 70 in parallel sealed system embodiments).

[0047] While supplying the fresh food evaporator 71, e.g., as indicated at (742), method 700 may include warming the freezer evaporator 70. Warming the freezer evaporator 70 may include operating the freezer fan 74 and/or operating an ice box fan (which is not specifically illustrated but which may be in and/or in fluid communication with the ice box 150 to motivate a flow of air between the freezer evaporator 70 and the ice box 150). In particular, as illustrated in FIG. 7, the freezer fan 74 may be operated first (e.g., at (742)) followed by operating the ice box fan 150 (e.g., as indicated at (744) in FIG. 7). For example, the freezer fan 74 may be operated for a first predetermined time period and/or until the temperature of the freezer evaporator 70 reaches or approaches the freezer compartment 124 temperature. The predetermined time period may be, e.g., between about one minute and about five minutes, such as about two minutes or about three minutes. After operating the freezer fan 74 at (742) (and while continuing to supply liquid refrigerant to the fresh food evaporator 71) method 700 may then operate the ice box fan to further warm the freezer evaporator 70, e.g., as illustrated at (744) in FIG. 7. For example, the ice box fan may be operated simultaneously with the fresh food fan 75 to cool both the fresh food compartment 122 and the ice box 150.

[0048] In some embodiments, method 700 may further include (746) adjusting the ice box fan speed such that the ice box target (e.g., setpoint) temperature is achieved simultaneously or slightly before (e.g., within a predetermined time threshold) the fresh food compartment 122 target temperature is reached. For example, the fresh food capillary tube (or other second expansion device 69), evaporator configuration, and refrigerant charge may be selected such that there is sufficient capacity to cool the ice box 150 in ice storage mode during cooling of the fresh food compartment 122.

[0049] In some embodiments, method 700 may also include (748) monitoring or checking the suction line temperature (e.g., at or proximate to the inlet of the compressor 64). For example, such monitoring may be used to ensure the suction line does not get too cold (where the suction line getting too cold may lead to undesired migration of the refrigerant). The suction line temperature may be monitored using a temperature sensor and/or may be estimated using an algorithm based on the evaporator temperature.

[0050] Referring now generally to FIGS. 6 and 7, the methods 600 and/or 700 may be interrelated and/or may have one or more steps from one of the methods 600 and 700 combined with the other method 600 or 700. Thus, those of ordinary skill in the art will recognize that the various steps of the exemplary methods described herein may be combined in various ways to arrive at additional embodiments within the scope of the present disclosure. FIGS. 6 and 7 depict steps in a particular order for purpose of illustration and discussion. Those of ordinary skill in the art, using the disclosures provided herein, will understand that (except as otherwise indicated) methods 600 and 700 are not mutually exclusive. For example, warming the freezer evaporator while directing the flow of liquid refrigerant through the sealed system to the fresh food evaporator, e.g., as in (620), may include operating the freezer fan 74 (e.g., as in (742)) and/or operating the ice box fan (e.g., as in (744)). Moreover, the steps of the methods 600 and 700 can be modified, adapted, rearranged, omitted, interchanged, or expanded in various ways without deviating from the scope of the present disclosure.

[0051] Methods according to the present disclosure may permit operating the fresh food evaporator at a warmer, more efficient temperature, while also decoupling the evaporators, e.g., mitigating or preventing refrigerant migration from the fresh food evaporator during fresh food cooling operations. By warming the freezer evaporator while directing the refrigerant flow to the fresh food evaporator, the temperature difference between the evaporators may be reduced, and reducing the temperature difference decouples the evaporators. Thus, the fresh food evaporator may be operated at the warmer, more efficient temperature without undesired refrigerant migration and without additional hardware, e.g., a check valve coupled between the evaporators.

[0052] Exemplary methods according to the present disclosure may also include monitoring a temperature of a suction line of the sealed system. In such embodiments, the temperature may be monitored in order to ensure the suction line does not get too cold. For example, such embodiments may include comparing the monitored temperature of the suction line to a minimum temperature.

[0053] In some embodiments, warming the freezer evaporator while directing the flow of liquid refrigerant through the sealed system to the fresh food evaporator (e.g., at (620) in FIG. 6) may include operating an ice box fan. Operating the ice box fan may cause air to be circulated between the freezer evaporator and an ice box of the refrigerator appliance. In such embodiments, the air circulated between the freezer evaporator and the ice box may not flow through a freezer compartment of the refrigerator appliance. For example, a duct may be provided which extends directly between the ice box 150 and the freezer evaporator 70, thereby bypassing the freezer compartment 124 or otherwise not flowing air also through the freezer compartment 124 while circulating between the freezer evaporator 70 and the ice box 150. In embodiments where warming the freezer evaporator 70 includes operating the ice box fan, the ice box fan may be operated at a predetermined or preselected speed, and the speed may be selected such that an ice box target temperature is reached approximately simultaneously with a fresh food target temperature, such as slightly before the fresh food target temperature is reached.

[0054] In some embodiments, warming the freezer evaporator while directing the flow of liquid refrigerant through the sealed system to the fresh food evaporator (e.g., at (620) in FIG. 6) may include operating a freezer fan, which causes air to be circulated between the freezer evaporator 70 and a freezer compartment 124 of the refrigerator appliance 100. Such embodiments may further include, after operating the freezer fan while directing the flow of liquid refrigerant through the sealed system 60 to the fresh food evaporator 71, deactivating the freezer fan 74 when a temperature of the freezer evaporator 70 is approximately equal to a temperature of the freezer compartment 124 of the refrigerator appliance 100, such as when the temperature of the freezer evaporator 70 approaches the temperature of the freezer compartment 124. In such embodiments, warming the freezer evaporator 70 may further include operating an ice box fan, which causes air to be circulated between the freezer evaporator 70 and the ice box 150 of the refrigerator appliance 100, while directing the flow of liquid refrigerant through the sealed system 60 to the fresh food evaporator 71. For example, the ice box fan may be operated to circulate air between the freezer evaporator 70 and the ice box 150 after deactivating the freezer fan 74.

[0055] In some embodiments, warming the freezer evaporator 70 may include raising a temperature of the freezer evaporator 70 above a temperature of the freezer compartment 124 of the refrigerator appliance 100, such as to the temperature of the ice box 150 (or within a predetermined threshold just below the ice box temperature), where the ice box 150 may be positioned in the fresh food compartment 122 (either stationarily or when the door is closed, as noted above), such that the ice box 150, while insulated from and colder than the fresh food compartment 122, is nonetheless warmer than the freezer compartment 124.

[0056] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.