REFRIGERATOR APPLIANCE COOLING SYSTEM

Description

FIELD OF THE INVENTION

The present disclosure relates generally to refrigerator appliances and more particularly to a features for generating and distributing chilled air within refrigerator appliances, such as chilled air systems or cooling systems.

BACKGROUND OF THE INVENTION

Refrigerator appliances generally include a cabinet that defines chilled chambers for receipt of food items for storage. One or more insulated, sealing doors are provided for selectively enclosing the chilled food storage chambers.

Refrigerator appliances typically utilize sealed systems for cooling the chilled chambers. A typical sealed system includes an evaporator and a fan, however, such refrigerator appliances usually include a separate evaporator for each chamber to achieve different temperatures in each of the chilled chambers.

Additional evaporators may result in added costs, more complicated assembly, a more complex refrigerant plumbing configuration, and reduced proportion of usable space within the internal volume of the refrigerator appliance.

Accordingly, refrigerator appliances and cooling systems for such appliances including a single evaporator for providing chilled air to multiple chambers therein is desired in the art.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention.

In an exemplary embodiment, a refrigerator appliance is provided. The refrigerator appliance defines a vertical direction, a lateral direction and a transverse direction. The vertical, lateral and transverse directions are mutually perpendicular. The refrigerator appliance includes a cabinet. A fresh food chamber and a freezer chamber are defined in the cabinet. The refrigerator appliance also includes a sealed cooling system configured to provide cooled air to the fresh food chamber and the freezer chamber. The sealed cooling system includes a sealed loop with a working fluid sealed within the sealed loop. The sealed cooling system also includes a compressor, a condenser downstream of the compressor with respect to the flow direction of the working fluid, and an evaporator downstream of the condenser with respect to the flow direction of the working fluid. An expansion device is between the condenser and the evaporator. The sealed cooling system further includes a modulator having a reservoir and a supply conduit. The reservoir of the modulator is positioned around an outlet conduit of the evaporator. A first end portion of the supply conduit is coupled to an inlet conduit of the evaporator. A second end portion of the supply conduit is coupled to the reservoir of the modulator. The working fluid is flowable into and out of the reservoir of the modulator through the supply conduit of the modulator.

In another exemplary embodiment, a sealed cooling system for a refrigerator appliance is provided. The refrigerator appliance includes a cabinet with a fresh food chamber and a freezer chamber defined in the cabinet. The sealed cooling system includes a sealed loop with a working fluid sealed within the sealed loop. The sealed cooling system also includes a compressor, a condenser downstream of the compressor with respect to the flow direction of the working fluid, and an evaporator downstream of the condenser with respect to the flow direction of the working fluid. An expansion device is between the condenser and the evaporator. The sealed cooling system further includes a modulator having a reservoir and a supply conduit. The reservoir of the modulator is positioned around an outlet conduit of the evaporator. A first end portion of the supply conduit is coupled to an inlet conduit of the evaporator. A second end portion of the supply conduit is coupled to the reservoir of the modulator. The working fluid is flowable into and out of the reservoir of the modulator through the supply conduit of the modulator.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

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.

FIG. 1 provides a perspective view of an exemplary refrigerator appliance according to one or more embodiments of the present subject matter.

FIG. 2 provides an additional perspective view of the exemplary refrigerator appliance of FIG. 1 with doors of the refrigerator appliance in an open position.

FIG. 3 provides a schematic side section view of the exemplary refrigerator appliance of FIG. 1 with a damper assembly in a first position.

FIG. 4 provides an enlarged view of a portion of FIG. 3.

FIG. 5 provides a schematic side section view of the exemplary refrigerator appliance of FIG. 1 with the damper assembly in a second position.

FIG. 6 provides an enlarged view of a portion of FIG. 5.

FIG. 7 provides a schematic illustration of an exemplary cooling system which may be incorporated into a refrigerator appliance such as the exemplary refrigerator appliance of FIG. 1.

FIG. 8 provides another schematic illustration of the exemplary cooling system of FIG. 7.

FIG. 9 provides a schematic illustration of an exemplary modulator which may be incorporated into a cooling system such as the exemplary cooling system of FIG. 7 and/or a refrigerator appliance such as the exemplary refrigerator appliance of FIG. 1.

DETAILED DESCRIPTION

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.

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. Terms such as “inner” and “outer” refer to relative directions with respect to the interior and exterior of the refrigerator appliance, and in particular the food storage chamber(s) defined therein. For example, “inner” or “inward” refers to the direction towards the interior of the refrigerator appliance. Terms such as “left,” “right,” “front,” “back,” “top,” or “bottom” are used with reference to the perspective of a user accessing the refrigerator appliance. For example, a user stands in front of the refrigerator to open the doors and reaches into the food storage chamber(s) to access items therein.

As used herein, terms of approximation such as “generally,” “about,” or “approximately” 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, e.g., “generally vertical” includes forming an angle of up to ten degrees in any direction, e.g., clockwise or counterclockwise, with the vertical direction V.

Referring now to the figures, FIGS. 1 and 2 provide perspective views of an exemplary refrigerator appliance 100, according to one or more exemplary embodiments of the present subject matter. The refrigerator appliance may define a vertical direction V, a lateral direction L, and a transverse direction T. The vertical direction V, the lateral direction L, and the transverse direction T may each be mutually perpendicular to one another to generally form an orthogonal coordinate system.

As illustrated in FIGS. 1 and 2, the refrigerator appliance 100 may include a housing or a cabinet 102 that may extend between a top 104 and a bottom 106 approximately along a vertical direction V, between a first side (left side) 108 and a second side (right side) 110 approximately along a lateral direction L, and between a front 112 and a back 114 approximately along a transverse direction T. The cabinet 102 may define one or more chilled chambers for receipt of food items for storage. In some embodiments, the cabinet 102 may define a fresh food chamber 122 positioned at or adjacent the top 104 of the cabinet 102 and a freezer chamber 124 arranged at or adjacent the bottom 106 of the cabinet 102. As such, the refrigerator appliance 100 may generally be 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 such as, for example, a top mount refrigerator appliance, a quad door refrigerator appliance, a side-by-side refrigerator, or other similar 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 household appliance, such as the present subject matter is not limited to any particular refrigerator chamber configuration. Accordingly, it should be recognized that aspects of the present disclosure may be used with a variety of refrigerator appliances.

The refrigerator doors 128 may be rotatably hinged to an edge of the cabinet 102 for selectively accessing the fresh food chamber 122. In addition, a freezer door 130 may be arranged below the refrigerator doors 128 for selectively accessing the freezer chamber 124. The freezer door 130 may be coupled to a freezer drawer 132 (see, e.g., FIGS. 3 and 5) slidably mounted within the freezer chamber 124. The refrigerator doors 128 and the freezer door 130 are shown in the closed configuration in FIG. 1.

In some embodiments, various storage components may be mounted within the fresh food chamber 122 to facilitate storage of food items therein. In particular, the storage components may include storage bins 116, drawers 118, and shelves 121 that may be mounted within the fresh food chamber 122. As such, the storage bins 116, drawers 118, and shelves 121 are configured for receipt of food items, for example, beverages or solid food items, and may assist with organizing such food items. As an example, the drawers 118 can receive fresh food items, for example, vegetables, fruits, or cheeses, and increase the useful life of such fresh food items.

In some embodiments, the refrigerator appliance 100 may also include a dispensing assembly 140 for dispensing liquid water or ice. The dispensing assembly 140 may include a dispenser 142, for example, positioned on or mounted to an exterior portion of the refrigerator appliance 100, such as on one of the refrigerator doors 128. Moreover, as shown in FIG. 1, the dispenser 142 may include a discharging outlet 144 for accessing ice and liquid water. Further, an actuating mechanism 146, shown as a paddle, may be mounted below the discharging outlet 144 for operating the dispenser 142. In alternative embodiments, any suitable actuating mechanism may be used to operate the dispenser 142. A user interface panel 148 may also be provided for controlling the mode of operation. For example, the user interface panel 148 may include a plurality of user inputs (not labeled), 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.

Still referring to FIG. 1, the discharging outlet 144 and actuating mechanism 146 may be an external part of the dispenser 142 and may be mounted in a dispenser recess 150. The dispenser recess 150 may be positioned at a predetermined elevation convenient for a user to access ice or water and enabling the user to access ice without the need to bend over and without the need to open the refrigerator doors 128. In additional embodiments, the dispenser recess 150 may be positioned at a level that approximates the chest level of a user.

In further embodiments, for example, as shown in FIG. 2, the refrigerator appliance 100 may include a sub-compartment 162 defined on the refrigerator door 128. The sub-compartment 162 is often referred to as an “icebox.” Further, the sub-compartment 162 may extend into fresh food chamber 122 when the refrigerator door 128 is in the closed position. Although the sub-compartment 162 is shown in the refrigerator door 128, additional or alternative embodiments may include the sub-compartment 162 fixed within fresh food chamber 122. In an embodiment, an ice maker and/or an ice storage bin (not shown) may be positioned or disposed within the sub-compartment 162. Accordingly, during use, ice can be supplied to the dispenser recess 150, see, for example, FIG. 1, from the ice making assembly or ice storage bin in the sub-compartment 162 on a back side of refrigerator door 128.

In additional or alternative embodiments, chilled air from a sealed system of the refrigerator appliance 100 may be directed into components within the sub-compartment 162. For instance, the sub-compartment 162 may receive cooling air from a chilled air supply duct 165 and a chilled air return duct 167 (see, for example, FIG. 2), disposed on a side portion of cabinet 102 of the refrigerator appliance 100. In this manner, the chilled air supply duct 165 and the chilled air return duct 167 may recirculate chilled air from a suitable sealed cooling system through the sub-compartment 162.

In optional embodiments, for example, as illustrated in FIG. 2, an access door 166 may be hinged to the refrigerator door 128. Thus, the access door 166 may permit selective access to the sub-compartment 162. Any manner of suitable latch 168 may be configured with the sub-compartment 162 to maintain the access door 166 in a closed position. As an example, the latch 168 may be actuated by a user in order to open the access door 166 for providing access into the sub-compartment 162. The access door 166 can also assist with insulating the sub-compartment 162 (e.g., by thermally isolating or insulating the sub-compartment 162 from the fresh food chamber 122). It is noted that although the access door 166 is illustrated in exemplary embodiments, alternative embodiments may be free of any separate access door.

Refrigerator appliance 100 further includes a controller 160. Operation of the refrigerator appliance 100 is regulated by controller 160 that is operatively coupled to user interface panel 148. In some exemplary embodiments, user interface panel 148 may represent a general purpose I/O (“GPIO”) device or functional block. In some exemplary embodiments, user interface panel 148 may include input components, such as one or more of a variety of electrical, mechanical or electro-mechanical input devices including rotary dials, push buttons, touch pads, and touch screens. User interface panel 148 can be communicatively coupled with controller 160 via one or more signal lines or shared communication busses. User interface panel 148 provides selections for user manipulation of the operation of refrigerator appliance 100, e.g., whereby a user may provide one or more set point temperatures for the various chilled chambers 122 and 124. In response to user manipulation of the user interface panel 148, controller 160 operates various components of refrigerator appliance 100. For example, controller 160 is operatively coupled or in communication with various airflow components, e.g., dampers and fans, as discussed below. Controller 160 may also be communicatively coupled with a variety of sensors, such as, for example, chamber temperature sensors or ambient temperature sensors. Such chamber temperature sensors and/or ambient temperature sensors may be or include thermistors, thermocouples, or any other suitable temperature sensor. Controller 160 may receive signals from these temperature sensors that correspond to the temperature of an atmosphere or air within their respective locations.

As used herein, the terms “processing device,” “computing device,” “controller,” or the like may generally refer to any suitable processing device, such as a general or special purpose microprocessor, a microcontroller, an integrated circuit, an application specific integrated circuit (ASIC), a digital signal processor (DSP), a field-programmable gate array (FPGA), a logic device, one or more central processing units (CPUs), a graphics processing units (GPUs), processing units performing other specialized calculations, semiconductor devices, etc. In addition, these “controllers” are not necessarily restricted to a single element but may include any suitable number, type, and configuration of processing devices integrated in any suitable manner to facilitate appliance operation. Alternatively, controller 160 may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND/OR gates, and the like) to perform control functionality instead of relying upon software.

Controller 160 may include, or be associated with, one or more memory elements or non-transitory computer-readable storage mediums, such as RAM, ROM, EEPROM, EPROM, flash memory devices, magnetic disks, or other suitable memory devices (including combinations thereof). These memory devices may be a separate component from the processor or may be included onboard within the processor. In addition, these memory devices can store information and/or data accessible by the one or more processors, including instructions that can be executed by the one or more processors. It should be appreciated that the instructions can be software written in any suitable programming language or can be implemented in hardware. Additionally, or alternatively, the instructions can be executed logically and/or virtually using separate threads on one or more processors.

For example, controller 160 may be operable to execute programming instructions or micro-control code associated with an operating cycle of refrigerator appliance 100. In this regard, the instructions may be software or any set of instructions that when executed by the processing device, cause the processing device to perform operations, such as running one or more software applications, displaying a user interface, receiving user input, processing user input, etc. Moreover, it should be noted that controller 160 as disclosed herein is capable of and may be operable to perform any methods, method steps, or portions of methods as disclosed herein. For example, in some embodiments, methods disclosed herein may be embodied in programming instructions stored in the memory and executed by controller 160.

The memory devices may also store data that can be retrieved, manipulated, created, or stored by the one or more processors or portions of controller 160. The data can include, for instance, data to facilitate performance of methods described herein. The data can be stored locally (e.g., on controller 160) in one or more databases and/or may be split up so that the data is stored in multiple locations. In addition, or alternatively, the one or more database(s) can be connected to controller 160 through any suitable network(s), such as through a high bandwidth local area network (LAN) or wide area network (WAN). In this regard, for example, controller 160 may further include a communication module or interface that may be used to communicate with one or more other component(s) of refrigerator appliance 100, controller 160, an external appliance controller, or any other suitable device, e.g., via any suitable communication lines or network(s) and using any suitable communication protocol. The communication interface can include any suitable components for interfacing with one or more network(s), including for example, transmitters, receivers, ports, controllers, antennas, or other suitable components.

Referring now to FIGS. 3 through 6 generally, the refrigerator appliance 100 may include an insulated mullion 170 between the fresh food chamber 122 and the freezer chamber 124. For example, the freezer chamber 124 may be spaced apart from the fresh food chamber 122 and separated from the fresh food chamber 122 by the insulated mullion 170, such that the insulated mullion 170 partially defines each of the fresh food chamber 122 and the freezer chamber 124, and where the thermal insulation of the insulated mullion 170 promotes operation of the fresh food chamber 122 and the freezer chamber 124 at distinct temperatures, as is understood by those of ordinary skill in the art.

The refrigerator appliance 100 may further include a bridge chamber 200. The bridge chamber 200 may be partially, e.g., on at least one side, defined by the insulated mullion 170. The bridge chamber 200 may further be defined by one or more additional insulated partitions 202, such that the bridge chamber 200 may be operated at a distinct temperature from the operating temperature of one or both of the fresh food chamber 122 and freezer chamber 124. The bridge chamber 200 may include a first inlet 204 in fluid communication with the fresh food chamber 122 and a first outlet 206 in fluid communication with the fresh food chamber 122. The bridge chamber 200 may further include a second inlet 208 in fluid communication with the freezer chamber 124 and a second outlet 210 in fluid communication with the freezer chamber 124. The refrigerator appliance 100 may further include a movable damper assembly, such as a first curved damper 212 and a second curved damper 214. The movable damper assembly may be movable, e.g., rotatable, between a first position, e.g., for a fresh food mode, and a second position, e.g., for a freezer mode.

The refrigerator appliance 100 may further include a sealed cooling system, as is generally understood by those of ordinary skill in the art. For example, the sealed cooling system may include a sealed refrigerant loop with heat exchangers coupled in line with the sealed refrigerant loop (e.g., for series flow through the sealed refrigerant loop and successively through the heat exchangers). The heat exchangers may include a condenser 226 (FIGS. 7 and 8), in which vapor phase refrigerant condenses to liquid phase, thereby releasing heat to the external environment at the condenser, and an evaporator 220, in which liquid phase refrigerant absorbs heat from the external environment (e.g., air around the evaporator 220) and thereby vaporizes, such that a flow of chilled air may be generated at and around the evaporator 220. A fan 222 may be positioned proximate to the evaporator 220, such that the fan 222 is sufficiently close to the evaporator 220 to urge the chilled air generated at the evaporator 220 to or towards one of the chilled chambers (fresh food chamber 122 and freezer chamber 124) of the refrigerator appliance 100.

In particular, the evaporator 220 and the fan 222 may be positioned in the bridge chamber 200, such that the flow of chilled air urged by the fan 222 may be directed from the bridge chamber 200 to one or the other (or both) of the fresh food chamber 122 and the freezer chamber 124. For example, the flow of chilled air from the bridge chamber 200 (urged by fan 222) may be obstructed from one of the chambers and directed to the other of the chambers by the movable damper assembly. As mentioned above, the movable damper assembly may be movable between a first position and a second position, such as the first curved damper 212 may obstruct the second outlet 210 in the first position (FIGS. 3 and 4) and the first curved damper 212 may obstruct the first outlet 206 in the second position (FIGS. 5 and 6), while the second curved damper 214 may obstruct the second inlet 208 in the first position (FIGS. 3 and 4) and may obstruct the first inlet 204 in the second position (FIGS. 5 and 6). Thus, the movable damper assembly may obstruct the flow of chilled air from the bridge chamber 200 to the freezer chamber 124 in the first position, and may direct the flow of chilled air from the bridge chamber 200 into the fresh food chamber 122 in the first position. Similarly, when the damper assembly is in the second position, the movable damper assembly may obstruct the flow of chilled air from the bridge chamber 200 to the fresh food chamber 122 and guide or direct the flow of chilled air from the bridge chamber 200 to the freezer chamber 124.

In at least some embodiments, the evaporator 220 in the bridge chamber 200 may be the only evaporator 220 in the sealed cooling system, such as the evaporator 220 in the bridge chamber 200 may be the only evaporator of the refrigerator appliance 100. Thus, for example, the movable damper assembly may provide selective cooling to one or the other of the fresh food chamber 122 and the freezer chamber 124, such that the single evaporator 220 for the entire refrigerator appliance 100 may provide cooling to both chilled chambers 122 and 124. In at least some embodiments, the movable damper assembly may also be movable to one or more intermediate positions between the first position and the second position, such that chilled air from the bridge chamber 200 may be directed to both chilled chambers 122 and 124 at the same time, such as in a cool down mode. For example, the cool down mode may be implemented when the refrigerator appliance is first commissioned, after a power outage, or in other cases when a temperature in each chamber 122 and 124 (such as may be measured by chamber temperature sensor(s), as described above) is significantly greater than a respective set temperature or target temperature for each chamber 122 and 124.

Still referring to FIGS. 3-6 in general, the refrigerator appliance 100 may further include a plurality of plenums within the bridge chamber 200. For example, the evaporator 220 and the fan 222 may be spaced apart from each other within the bridge chamber 200 and spaced apart from the inlets (204 and 208) and outlets (206 and 210) of the bridge chamber 200, to thereby define the plenums within the bridge chamber 200. For example, the refrigerator appliance 100 may include a first plenum 230 within the bridge chamber 200 upstream of the fresh food chamber 120 and/or freezer chamber 124, such as the first plenum 230 may be downstream of the evaporator 220, e.g., immediately downstream of the evaporator 220 as illustrated. Thus, in some embodiments, e.g., as illustrated in FIGS. 3-6, the first plenum 230 may be defined between the evaporator 220 and the outlets 206 and 210 of the bridge chamber 200. In additional embodiments, the positions of the fan 222 and the evaporator 220 may be reversed, e.g., the fan 222 may be downstream of the evaporator 220, such that the first plenum 230 would be defined between the fan 222 and the outlets 206 and 210 of the bridge chamber 200.

Also by way of example, the refrigerator appliance 100 may include a second plenum 234 within the bridge chamber 200 downstream of the fresh food chamber 120 and/or freezer chamber 124, such as the first plenum 230 may be upstream of the fan 222, e.g., immediately upstream of the fan 222 as illustrated. Thus, in some embodiments, e.g., as illustrated in FIGS. 3-6, the second plenum 234 may be defined between the inlets 204 and 208 of the bridge chamber 200 and the fan 222. In additional embodiments where the positions of the fan 222 and the evaporator 220 are reversed, the second plenum 234 may be defined between the inlets 204 and 208 of the bridge chamber 200 and the evaporator 220.

In some embodiments, the first damper 212 may be positioned in and movable through the first plenum 230, and the second damper 214 may be positioned in and movable through the second plenum 234. In some embodiments, the evaporator 220 and the fan 222 may be spaced apart from each other, such that an intermediate plenum 232 may be defined between the evaporator 220 and the fan 222, such as directly and immediately between the evaporator 220 and the fan 222, e.g., as illustrated.

In some embodiments, the refrigerator appliance 100, e.g., the sealed cooling system thereof, may further include a variable speed compressor 224 (FIGS. 4 and 6) coupled to the evaporator 220. The controller 160 may be in operative communication with the variable speed compressor 224, such as to operate the variable speed compressor 224 at a plurality of speeds within an operating range of the variable speed compressor 224. The operating speed of the variable speed compressor 224 may control a flow rate of liquid phase refrigerant to the evaporator 220, and thus control the rate of cooling provided by the sealed cooling system. In such embodiments, the controller 160 may be configured to operate the variable speed compressor 224 at a first speed when the damper assembly is in the first position and to operate the variable speed compressor 224 at a second speed different from the first speed when the damper assembly is in the second position. For example, the variable speed compressor 224 may be operated at a higher rate to provide increased cooling when in freezer mode (e.g., when the damper assembly is in the second position) and may be operated at a lower rate to provide increased efficiency when in fresh food mode (e.g., when the damper assembly is in the first position).

An exemplary fresh food mode is illustrated in FIGS. 3 and 4, e.g., where the damper assembly (comprising first curved damper 212 and second curved damper 214) is in the first position, such that air flow from the bridge chamber 200 to the freezer chamber 124 is obstructed, and air flow is guided to the fresh food chamber 122. As may be seen in FIG. 3, when in the fresh food mode, a flow of supply air SA is provided to the fresh food chamber 122 from the bridge chamber 200 via the first outlet 206. In some embodiments, an aperture (not labelled) may be defined through the insulated mullion 170 at the first outlet 206, such that the supply air SA is directed to the fresh food chamber 122 via the aperture through the insulated mullion 170 at the first outlet 206 of the bridge chamber 200. In some embodiments, the refrigerator appliance 100 may further include an air tower 172 through which the supply air SA is directed into and distributed in the fresh food chamber 122 through multiple outlets of the air tower, such as the air tower 172 may include an outlet at one or more storage elements in the fresh food chamber, such as at each drawer 118 and shelf 121 within the fresh food chamber 122. In such embodiments, the first outlet 206 of the bridge chamber 200 may be upstream of the air tower 172 in the fresh food chamber 122. After circulating through the fresh food chamber 122, the air may return to the bridge chamber 200, such as a flow of return air RA may enter the bridge chamber 200 at the first inlet 204 while in the fresh food mode, such as the return air RA may flow through another aperture in the insulated mullion to reach the first inlet 204 of the bridge chamber 200.

An exemplary freezer mode is illustrated in FIGS. 5 and 6, e.g., where the damper assembly (comprising first curved damper 212 and second curved damper 214) is in the second position, such that air flow from the bridge chamber 200 to the fresh food chamber 122 is obstructed, and air flow is guided to the freezer chamber 124. As may be seen in FIG. 5, when in the freezer mode, the flow of supply air SA is provided to the freezer chamber 124 from the bridge chamber 200 via the second outlet 210. In some embodiments, the second outlet 210 may open directly into the freezer chamber 124. In some embodiments, air flow within and through the freezer chamber 124 may be guided by (e.g., around) one or more storage elements, such as drawer 132, e.g., as illustrated in FIG. 5. As may be seen in FIG. 5, drawer 132 defines a portion of a flow path for chilled air within the freezer chamber 124, e.g., from the second outlet 210 of the bridge chamber 200 across a floor of the freezer chamber 124 and upwards at the front of the freezer chamber 124. After circulating through the freezer chamber 124, the air may return to the bridge chamber 200, such as the return air RA may enter directly into the bridge chamber 200 at the second inlet 208 while in the freezer mode.

Referring now to FIGS. 7 and 8, a cooling system 225 according to one or more example embodiments of the present disclosure is illustrated. In particular, the cooling system 225 may include an accumulator or modulator 300, which will be described further hereinbelow, and FIG. 7 illustrates the cooling system 225 in a first condition, such as when operating in one of fresh food mode or freezer mode, while FIG. 8 illustrates the cooling system 225 in second condition which is an overcharged condition, such when operating in the other of the fresh food mode or the freezer mode. As may be seen from FIGS. 7 and 8, the modulator 300, e.g., an internal volume 312 (FIG. 9) of a reservoir 310 of the modulator 300 may fill with a first, smaller, amount of liquid phase refrigerant when the system is not overcharged (FIG. 7) and may fill with a second, larger, amount of liquid phase refrigerant when the system is overcharged (FIG. 8). Thus, the modulator may prevent or limit liquid phase refrigerant from flowing to the compressor 224, e.g., whereby compressor 224 receives solely or predominantly gas phase or vapor phase refrigerant, even when the system is overcharged.

As illustrated in FIGS. 7 and 8, the sealed cooling system 225 may be operable for executing a known vapor compression cycle, and the sealed cooling system 225 may include a series of interconnected conduits which generally form a loop through which a working fluid, e.g., refrigerant, flows while the working fluid is sealed and contained within the conduits of the cooling system 225. The cooling system 225 includes the compressor 224, e.g., which may be a variable speed compressor as discussed above, a condenser 226, at least one expansion device 228 (e.g., a capillary tube as illustrated or an electronic expansion valve or other similar expansion device), and the evaporator 220. The sealed cooling system 225 may further include the modulator 300.

Within cooling system 225, refrigerant flows into compressor 224, which operates to increase the pressure of the refrigerant. This compression of the refrigerant raises a temperature of the refrigerant, which is lowered by passing the refrigerant through condenser 226. Within condenser 226, heat exchange with ambient air takes place so as to cool the refrigerant. A fan (not shown) may be used to urge air across condenser 226 so as to provide forced convection for a more rapid and efficient heat exchange between the refrigerant within condenser 226 and the ambient air. Thus, as will be understood by those skilled in the art, increasing air flow across condenser 226 can, e.g., increase the efficiency of condenser 226 by improving cooling of the refrigerant contained therein.

An expansion device (e.g., a valve, capillary tube, or other restriction device) 228 receives refrigerant from condenser 226. From expansion device 228, the refrigerant enters evaporator 220. Upon exiting expansion device 228 and entering evaporator 220, the refrigerant drops in pressure. Due to the pressure drop and/or phase change of the refrigerant, evaporator 220 is cool relative to refrigerator appliance 100, e.g., air within one or both of the chilled chambers (fresh food chamber 122 and freezer chamber 124). Thus, evaporator 220 is a type of heat exchanger which transfers heat from air within refrigerator appliance 100 to refrigerant flowing through evaporator 220.

The cooling system 225 depicted in FIGS. 7 and 8 is provided by way of example only. Thus, it is within the scope of the present subject matter for other configurations of the refrigeration system to be used as well. For example, additional or other expansion devices may be used, such as more than one capillary tube may be provided, among other possible variations.

As mentioned, cooling system 225 also includes modulator 300. Modulator 300 is configured for adjusting the charge of refrigerant flowing within cooling system 225, as discussed in greater detail below. As shown in FIGS. 7 and 8, modulator 300 includes a reservoir 310 and a supply conduit 320. Reservoir 310 is positioned on an outlet conduit 164 of evaporator 220. The outlet conduit 164 of evaporator 220 may extend from evaporator 220, and refrigerant exiting evaporator 220 may flow through outlet conduit 164 towards compressor 224. In contrast, an inlet conduit 262 of evaporator 220 may extend to evaporator 220, and refrigerant flowing from expansion device 228 may flow through inlet conduit 262 into evaporator 220.

Supply conduit 320 extends between and connects reservoir 310 and inlet conduit 262 of evaporator 220. Thus, refrigerant at inlet conduit 262 of evaporator 220 may flow into reservoir 310 via supply conduit 320. In addition, refrigerant within reservoir 310 may flow into inlet conduit 262 of evaporator 220 via supply conduit 320. Thus, refrigerant is flowable into and from reservoir 310 through supply conduit 320. As discussed in greater detail below, modulator 300 may draw refrigerant from inlet conduit 262 into reservoir 310 via supply conduit 320 or may supply refrigerant from reservoir 310 into inlet conduit 262 via supply conduit 320, e.g., based on the temperature of refrigerant within outlet conduit 164 of evaporator 220.

FIG. 9 is a schematic view of modulator 300. As shown in FIG. 9, supply conduit 320 may extend between a first end portion 322 and a second end portion 324. First end portion 322 of supply conduit 320 may be coupled to inlet conduit 262 (FIGS. 7 and 8). Thus, refrigerant from inlet conduit 262 may enter supply conduit 320 at first end portion 322 of supply conduit 320. Similarly, refrigerant from reservoir 310 may exit supply conduit 320 and enter inlet conduit 262 at first end portion 322 of supply conduit 320. Second end portion 324 of supply conduit 320 may be coupled to reservoir 310. Thus, refrigerant from reservoir 310 may enter supply conduit 320 at second end portion 324 of supply conduit 320. Similarly, refrigerant from inlet conduit 262 may exit supply conduit 320 and enter reservoir 310 at second end portion 324 of supply conduit 320. Reservoir 310 may extend between a top portion 314 and a bottom portion 316, and second end portion 324 of supply conduit 320 may be positioned at top portion 314 of reservoir 310, e.g., within the top half or top third of the reservoir 310. Thus, e.g., refrigerant may enter and exit supply conduit 320 at top portion 314 of reservoir 310.

As noted above, reservoir 310 is positioned on outlet conduit 164. In particular, reservoir 310 may be positioned on outlet conduit 164 such that outlet conduit 164 is positioned concentrically with an interior volume 312 of reservoir 310. Thus, e.g., refrigerant within interior volume 312 of reservoir 310 may contact outlet conduit 164. To mount reservoir 310 on outlet conduit 164, reservoir 310 may be soldered to outlet conduit 164. For example, top and bottom portions 314, 316 of reservoir 310 may be soldered to outlet conduit 164. In alternative example embodiments, outlet conduit 164 may be positioned on an exterior surface of reservoir 310, e.g., such that outlet conduit 164 is positioned outside of interior volume 312 of reservoir 310. In particular, outlet conduit 154 may be soldered to the exterior surface of reservoir 310. In such example embodiments, heat transfer between refrigerant within reservoir 310 and refrigerant within outlet conduit 164 may be limited compared to the example arrangement shown in FIG. 9.

Supply conduit 320 provides a flow path for refrigerant in cooling system 225 to flow into and out of reservoir 310. In particular, modulator 300 may form a dead end branch for refrigerant within cooling system 225. Thus, interior volume 312 of reservoir 310 may not be in direct fluid communication with the interior of outlet conduit 164, and, while refrigerant (labeled L in FIG. 9) within interior volume 312 of reservoir 310 can contact an exterior of outlet conduit 164, the refrigerant L within interior volume 312 of reservoir 310 cannot flow directly into outlet conduit 164, e.g., without exiting reservoir 310 via supply conduit 320. While not able to bypass evaporator 220 via modulator 300, the refrigerant L within interior volume 312 may exchange heat with refrigerant within outlet conduit 164, as discussed in greater detail below.

Interior volume 312 of reservoir 310 may be sized to contain a suitable volume of refrigerant. As noted above, modulator 300 may draw refrigerant from inlet conduit 262 into reservoir 310 via supply conduit 320 or may supply refrigerant from reservoir 310 into inlet conduit 262 via supply conduit 320. The sizing of reservoir 310 may advantageously allow a desirable volume of refrigerant to be stored within reservoir 310, e.g., and thus not be cycled through cooling system 225. By sizing interior volume 312 of reservoir 310 to store a suitable volume of refrigerant, the reservoir 310 may advantageously allow modulator 300 to vary the volume of refrigerant flowing through cooling system 225.

Because the temperature of the refrigerant within evaporator 220 can vary dramatically between the fresh food mode and the freezer mode, the optimum charge of refrigerant to fully flood evaporator 220 constantly changes. As the evaporator temperature and pressure drops, so does the amount of refrigerant required to fully flood evaporator 220. Modulator 300 is configured to regulate the charge of refrigerant flowing through cooling system 225, e.g., and provide an optimum charge in evaporator 220 throughout both fresh food mode and freezer mode operations of the cooling system 225.

When evaporator 220 is fully flooded, the temperature of refrigerant within outlet conduit 164, i.e., the evaporator outlet temperature, is less than the temperature of refrigerant within inlet conduit 262, i.e., the evaporator inlet temperature, due to the pressure drop of refrigerant within evaporator 220. Such temperature differential between the evaporator outlet and inlet temperatures causes refrigerant within inlet conduit 262 to migrate towards interior volume 312 of reservoir 310 via supply conduit 320. Within interior volume 312 of reservoir 310, the refrigerant from inlet conduit 262 condenses and is stored, e.g., until evaporator 220 is not fully flooded.

When evaporator 220 is not fully flooded and does not have optimum charge, the refrigerant within outlet conduit 164 may become superheated. Thus, the evaporator outlet temperature increases. The hotter refrigerant within outlet conduit 164 may transfer heat to the refrigerant L within interior volume 312 of reservoir 310 and thereby increase the vapor pressure of the refrigerant L within interior volume 312 of reservoir 310. When the vapor pressure of the refrigerant L is greater than the vapor pressure of refrigerant in inlet conduit 262, refrigerant L within reservoir 310 migrates towards inlet conduit 262 and back into cooling system 225 via supply conduit 320.

As may be seen from the above, modulator 300 moves refrigerant into and out of cooling system 225 based on the evaporator outlet temperature. Modulator 300 may advantageously be a passive system without moving parts. Thus, e.g., modulator 300 may regulate the charge of cooling system 225 based entirely on thermodynamics and vapor pressure, e.g., and without requiring sensors, control valves, etc. When evaporator 220 is low on charge, e.g., as can happen when the temperature and pressure of refrigerant within evaporator is high, the evaporator outlet temperature increases due to refrigerant superheating. Such superheating drives refrigerant stored in modulator 300 back out into cooling system 225, e.g., into evaporator 220. Conversely, when the evaporator outlet temperature is low due to evaporator 220 being fully flooded, the evaporator outlet temperature is less than the evaporator inlet temperature due to the pressure drop through evaporator 220. Such temperature differential drives refrigerant to migrate from inlet conduit 262 into modulator 300.

In an example operation of the refrigerator appliance 100 and/or cooling system 225 thereof, the operation may change from fresh food mode to freezer mode. Such transition may be advantageously made slowly, giving the modulator 300 time to adjust the effective charge without pushing a slug of liquid into the compressor 224. Thus, for example, the compressor speed may increase at a time offset compared with the switching of airflow paths (e.g., moving the damper assembly from the first position to the second position). Accordingly, the speed of compressor 224 may change (e.g., accelerate from the first speed to the second speed, as described above) following a ramp profile or other time/temperature-based profile.

By switching airflow paths (e.g., moving the damper assembly from the first position to the second position) before changing compressor speed, the air from freezer chamber 124 will cool the evaporator outlet, encouraging the modulator 300 to collect some refrigerant. When the evaporator 220 reaches a threshold temperature (such as 2° F. for instance) the speed of compressor 224 may shift (e.g., increase) to its target freezer cooling speed. In this way, the freezer chamber 124 may operate as a heat sink to smooth the transition between cooling modes and operate with a higher effective average charge; thereby gaining efficiency. Thus, the design may be more robust and the charge mass may be selected with less margin as a result.

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.