Patent Publication Number: US-2021172664-A1

Title: Adjustable cooling system

Description:
BACKGROUND OF THE DISCLOSURE 
     The present disclosure generally relates to an adjustable cooling system, and more specifically, to an adjustable cooling system for an appliance. 
     SUMMARY OF THE DISCLOSURE 
     According to one aspect of the present disclosure, an appliance includes a variable speed compressor. A first evaporator is operably coupled to the variable speed compressor. A second evaporator is operably coupled in series to the first evaporator. An electronic expansion valve is in fluid communication to the second evaporator and is configured to regulate a flow of thermal exchange media from the first evaporator to the second evaporator. 
     According to another aspect of the present disclosure, a refrigeration system for an appliance includes a compressor and a first evaporator. A second evaporator is operably coupled to the first evaporator. An electronic expansion valve is configured to regulate a thermal exchange media from the first evaporator into the second evaporator. A pressure regulator is operably coupled to the electronic expansion valve and the first evaporator. A controller is configured to control the electronic expansion valve. 
     According to yet another aspect of the present disclosure, a refrigeration system includes a variable speed compressor and a first evaporator. A second evaporator is operably coupled in series with the first evaporator. A first valve is coupled to the variable speed compressor and the first evaporator. A second valve is fluidly coupled to the second evaporator, and a pressure regulator is coupled to the second valve. 
     These and other features, advantages, and objects of the present disclosure will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG. 1  is a front perspective view of an appliance of the present disclosure; 
         FIG. 2  is a rear perspective view of the appliance of  FIG. 1  showing a machine compartment; 
         FIG. 3  is an expanded view of the machine compartment of  FIG. 2  taken at area III; 
         FIG. 4  is a schematic diagram of a refrigerating cycle of an adjustable cooling system of the present disclosure; and 
         FIG. 5  is a schematic diagram of a freezing cycle of an adjustable cooling system of the present disclosure. 
     
    
    
     The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles described herein. 
     DETAILED DESCRIPTION 
     The present illustrated embodiments reside primarily in combinations of method steps and apparatus components related to an adjustable cooling system. Accordingly, the apparatus components and method steps have been represented, where appropriate, by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Further, like numerals in the description and drawings represent like elements. 
     For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the disclosure as oriented in  FIG. 1 . Unless stated otherwise, the term “front” shall refer to the surface of the element closer to an intended viewer, and the term “rear” shall refer to the surface of the element further from the intended viewer. However, it is to be understood that the disclosure may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. 
     The terms “including,” “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “comprises a . . . ” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element. 
     Referring to  FIGS. 1-5 , reference numeral  10  generally designates an appliance. The appliance  10  includes a variable speed compressor  14  and a first evaporator  18  operably coupled to the variable speed compressor  14 . A second evaporator  22  is operably coupled in series to the first evaporator  18 . An electronic expansion valve  26  is in fluid communication with the second evaporator  22  and is configured to regulate a flow  30  of thermal exchange media  34  from the first evaporator  18  to the second evaporator  22 . A pressure regulator  38  is operably coupled to the electronic expansion valve  26 , and a controller  42  is configured to regulate the electronic expansion valve  26 . 
     An adjustable cooling system  50  includes a refrigerating cycle  54  and a freezing cycle  58 . Each of the refrigerating and freezing cycles  54 ,  58  utilize, under varying conditions, the variable speed compressor  14 , the first and second evaporators  18 ,  22 , the electronic expansion valve  26 , and the pressure regulator  38 . Typically, the electronic expansion valve  26  is used to alter the adjustable cooling system  50 . In one non-limiting example, the variable speed compressor  14  may be used to partially alter the adjustable cooling system  50 . In a further non-limiting example, both the variable speed compressor  14  and the electronic expansion valve  26  may be used together to alter the adjustable cooling system  50 . 
     Referring to  FIGS. 1-4 , the appliance  10  is illustrated as a French-door style refrigerator with a bottom-mounted drawer. It is also contemplated that the adjustable cooling system  50  can be used in other refrigeration constructions. The appliance  10  defines a refrigeration compartment  62  and a freezer compartment  66 . Additionally, the refrigerating cycle  54  and the freezing cycle  58  control an internal environment  70  of each of the refrigeration and freezer compartments  62 ,  66 , respectively. More specifically, the first evaporator  18  is primarily used for the cooling of the refrigeration compartment  62  during the refrigerating cycle  54 . Additionally or alternatively, while the first evaporator  18  may also used in cooling the freezer compartment  66 , the second evaporator  22 , in combination with the electronic expansion valve  26 , is the primary regulator of the freezer compartment  66 . The electronic expansion valve  26  may adjustably open and close to regulate the entry of the thermal exchange media  34  into the second evaporator  22 , which helps control the cooling of the freezer compartment  66 . 
     A machine compartment  74  generally defined by a rear portion  78  of the appliance  10  typically houses machine components  82  of the adjustable cooling system  50 , including, but not limited to, the variable speed compressor  14  and a condenser  86 . The first and second evaporators  18 ,  22 , and the pressure regulator  38  are connected in series with the variable speed compressor  14  and the condenser  86 . As the electronic expansion valve  26  is positioned in series with the first and second evaporators  18 ,  22 , the electronic expansion valve  26  is typically positioned near the second evaporator  22 . It is also contemplated that the adjustable cooling system  50  includes a first valve  90  as well as the electronic expansion valve  26 , which, in such configurations, may be referred to as the second valve  26 . The first valve  90  is typically positioned between the condenser  86  and the first evaporator  18 . In addition, the first valve  90  can be constructed as a capillary tube such that the first valve  90  is open to the thermal exchange media  34  passing through the first valve  90 . As the thermal exchange media  34  passes through the first valve  90 , a portion of the thermal exchange media  34  is expanded into a lower pressure liquid state  98 . 
     As illustrated in  FIGS. 4 and 5 , the portion of the thermal exchange media  34  in the gaseous state  94  is illustrated using a stipple pattern. The portion of the thermal exchange media  34  in the liquid state  98  is shown in a hatched pattern. As the thermal exchange media  34  moves through the adjustable cooling system  50 , these states of the thermal exchange media  34  are utilized to provide cooling to the first and second evaporators  18 ,  22  and, in turn, the refrigeration compartment  62  and the freezer compartment  66 . To achieve this, the state of the thermal exchange media  34 , as it moves through the system  50  can be entirely in the gaseous state  94 , entirely in the liquid state  98 , or both. When either the gaseous state  94  or the liquid state  98  is not present at a point in the system  50 , the respective state is illustrated by a broken line. 
     Referring to  FIGS. 3-5 , the first valve  90  receives the thermal exchange media  34  from the condenser  86 , which is coupled to the variable speed compressor  14 . The condenser  86  is configured to condense the gaseous state  94  of the thermal exchange media  34  and into the liquid state  98  of the thermal exchange media  34 . Stated differently, the thermal exchange media  34  in the gaseous state  94  travels from the variable speed compressor  14  to the condenser  86  where the thermal exchange media  34  is condensed from the gaseous state  94  into the liquid state  98 . The thermal exchange media  34  in the liquid state  98  is then transferred through the first valve  90  where it is expanded. When a capillary tube is used for the first valve  90 , the first valve  90  defines an initial pressure drop  92  that is fixed compared to a potential variable pressure drop across the electronic expansion valve  26 . It is also contemplated that the first valve  90  may also be an electronic expansion valve similar to the electronic expansion valve  26  described herein. In either construction, the first valve  90  provides the initial pressure drop  92  within the adjustable cooling system  50 . 
     As the thermal exchange media  34  leaves the first valve  90 , the thermal exchange media  34  in the liquid state  98  enters the first evaporator  18 . In the refrigerating cycle  54 , depicted in  FIG. 4 , the thermal exchange media  34  is almost entirely evaporated by the first evaporator  18  into the gaseous state  94 . After evaporation in the first evaporator  18 , the thermal exchange media  34  in the gaseous state  94  moves through the pressure regulator  38 , the electronic expansion valve  26 , and the second evaporator  22  while substantially remaining in the gaseous state  94 . For example, during the refrigerating cycle  54 , the thermal exchange media  34  in the gaseous state  94  typically entirely passes through the pressure regulator  38 . In addition, the electronic expansion valve  26  is set to be fully open during the refrigerating cycle  54 , such that the thermal exchange media  34  can pass through with minimal regulation by the electronic expansion valve  26 . The fan for the second evaporator  22  is typically off during the refrigerating cycle  54 , such that as the thermal exchange media  34  passes through the second evaporator  22  there is minimal additional cooling. 
     In conventional cooling systems, a capillary tube is used to define at least the first pressure drop. Conventional refrigerating systems may also use a second capillary tube to define subsequent pressure drops. The pressure drops in a conventional cooling system are unregulated by the first and second capillary tubes because capillary tubes operate in a binary fashion. For example, capillary tubes used in conventional cooling systems typically operate as open or closed without partial adjustments between open and closed. 
     Referring still to  FIGS. 3-5 , during the freezing cycle  58  and after expansion by the first valve  90 , the thermal exchange media  34  in the liquid state  98  is transferred to the first evaporator  18 . In the first evaporator  18 , the expanded thermal exchange media  34  will be at least partially evaporated, such that some of the thermal exchange media  34  is in the gaseous state  94  as it leaves the first evaporator  18 . In addition, some of the thermal exchange media  34  remains in the liquid state  98  after moving out of the first evaporator  18 . Accordingly, during the freezing cycle  58 , the thermal exchange media  34  will exit the first evaporator  18  while in an intermediate state  100 . The intermediate state  100  is defined as some of the thermal exchange media  34  being in the gaseous state  94  and the remainder of the thermal exchange media  34  being in the liquid state  98 . 
     It is contemplated that in the intermediate state  100 , after exiting the first evaporator  18 , the thermal exchange media  34  will be primarily in the gaseous state  94  with only a small amount of the thermal exchange media  34  existing in the liquid state  98 . Additionally or alternatively, the thermal exchange media  34  may be only partially in the gaseous state  94  when exiting the first evaporator  18 . Thus, it is also contemplated that the intermediate state  100  may be defined as the thermal exchange media  34  primarily in the liquid state  98 . The distribution of the thermal exchange media  34  in the gaseous and liquid states  94 ,  98  while in the intermediate state  100  may depend on the cooling specifications of the adjustable cooling system  50  in relation to the cooling specifications and temperature preferences and settings of each of the refrigeration and freezer compartments  62 ,  66 . 
     The thermal exchange media  34 , in either the intermediate state  100  or the gaseous state  94 , is then transferred from the first evaporator  18  into the pressure regulator  38 . Accordingly, the pressure regulator  38  is operably coupled to and in fluid communication with the first evaporator  18 . The pressure regulator  38  is typically a flash chamber that is configured to separate the thermal exchange media  34  in the gaseous state  94  from the thermal exchange media  34  in the liquid state  98 . As the thermal exchange media  34  continues to move through the adjustable cooling system  50 , the separation of the gaseous state  94  and the liquid state  98  is dependent upon whether the refrigerating cycle  54  or the freezing cycle  58  is in operation. 
     When the refrigerating cycle  54  is being operated, the thermal exchange media  34  typically passes through the pressure regulator  38  in either the gaseous state  94  or the intermediate state  100  and into the electronic expansion valve  26 . It is generally contemplated that during the refrigerating cycle  54  the thermal exchange media  34  is in the gaseous state  94  once the thermal exchange media  34  exits the first evaporator  18  and enters the pressure regulator  38 . Alternatively, if the freezing cycle  58  is operated, then the pressure regulator  38  will separate the thermal exchange media  34  into the gaseous state  94  and the liquid state  98 . The pressure regulator  38  will then hold the thermal exchange media  34  in the gaseous state  94  until the subsequent refrigerating cycle  54  is activated. Accordingly, the pressure regulator  38  separates the vapor and the liquid of the thermal exchange media  34  to regulate the pressure of the adjustable cooling system  50  depending on the cycle. 
     Referring again to  FIGS. 3-5 , during the refrigerating cycle  54 , all of the thermal exchange media  34 , regardless of whether in the gaseous state  94  or the liquid state  98 , is transferred through the electronic expansion valve  26 . Additionally or alternatively, during the freezing cycle  58 , the thermal exchange media  34  in the gaseous state  94  is retained within the pressure regulator  38 . In addition, the thermal exchange media  34  in the liquid state  98  is transferred from the pressure regulator  38  through the electronic expansion valve  26 . Accordingly, the thermal exchange media  34  in the gaseous state  94  is retained in the pressure regulator  38  until the next refrigerating cycle  54  is activated, as will be described more fully below. 
     While the pressure regulator  38  may at least partially separate the thermal exchange media  34 , it is contemplated that the flow of the thermal exchange media  34  between the first evaporator  18  and the second evaporator  22  is ultimately regulated by the electronic expansion valve  26 . Accordingly, the electronic expansion valve  26  is in fluid communication with both the first and second evaporators  18 ,  22 . Depending on the cycle run in the adjustable cooling system  50 , the thermal exchange media  34  can enter the electronic expansion valve  26  in either the liquid state  98  or the gaseous state  94 . As mentioned above, the thermal exchange media  34  enters the electronic expansion valve  26  in the gaseous state  94  during the refrigerating cycle  54 , such that the thermal exchange media  34  is evaporated by the first evaporator  18 . The resultant thermal exchange media  34  in the gaseous state  94  runs through the remainder of the adjustable cooling system  50  until it reaches the compressor  14 , discussed in further detail below. 
     During the freezing cycle  58 , the thermal exchange media  34  in the gaseous state  94  is temporarily stored in the pressure regulator  38  and the thermal exchange media  34  in the liquid state  98  is transferred to the electronic expansion valve  26 . The electronic expansion valve  26  selectively expands the thermal exchange media  34  that is still in the liquid state  98  before transferring the expanded thermal exchange media  34  to the second evaporator  22 . In selectively expanding, the controller  42  typically automatically adjusts the opening of the electronic expansion valve  26 . This adjustment is generally based on the percentage of thermal exchange media  34  in the liquid state  98  that is entering the electronic expansion valve  26  from the pressure regulator  38 . While the first valve  90  provides the initial pressure drop  92 , the electronic expansion valve  26  selectively controls and defines the second pressure drop  102 . 
     The second pressure drop  102  is regulated by the electronic expansion valve  26  and corresponds with the percentage of thermal exchange media  34  in the liquid state  98  that enters the electronic expansion valve  26 . Such regulation provides advantageous energy efficiency within the adjustable cooling system  50 . For example, the electronic expansion valve  26  can partially open in response to the percentage of thermal exchange media  34  that is entering the electronic expansion valve  26 . Accordingly, when there is a lower percentage of thermal exchange media  34  in the liquid state  98  entering the electronic expansion valve  26 , it is advantageous for the electronic expansion valve  26  to only partially open. Additionally or alternatively, when there is a high percentage of thermal exchange media  34  entering the electronic expansion valve  26 , then the electronic expansion valve  26  can be operated to fully open to accommodate a larger pressure drop. This selective control of the electronic expansion valve  26  controls the superheating of the thermal exchange media  34  within the adjustable cooling system  50  in an efficient manner. 
     Typically, the thermal exchange media  34  enters the electronic expansion valve  26  at a higher pressure and in the liquid state  98 . The remaining thermal exchange media  34  in the gaseous state  94  is retained in the pressure regulator  38 , discussed in further detail below. After passing through the electronic expansion valve  26 , the thermal exchange media  34  is in the intermediate state  100  at a lowered pressure. This change in pressure of the thermal exchange media  34  defines the second pressure drop  102 . Once through the electronic expansion valve  26 , the thermal exchange media  34  enters the second evaporator  22 , typically at the lowered pressure. This change in pressure is communicated to the controller  42 , which helps determine the rate at which thermal exchange media  34  is introduced into the second evaporator  22  from the electronic expansion valve  26 . 
     Accordingly, it is also contemplated that a sensor  110  can be coupled to the electronic expansion valve  26 . The sensor  110  can be a temperature sensor configured to sense the temperature of the thermal exchange media  34  as it passes through the second evaporator  22  from the electronic expansion valve  26 . In such an embodiment, based on the sensed temperature, the sensor  110  sends a signal to the controller  42  generally indicating the temperature of the thermal exchange media  34  in the adjustable cooling system  50 . The sensor  110  may also include an inlet sensor  114  and an outlet sensor  118  positioned upstream and downstream of the second evaporator  22  in the adjustable cooling system  50 . 
     As the thermal exchange media  34  leaves the electronic expansion valve  26  in the intermediate state  100 , the thermal exchange media  34  has a generally lowered pressure and lowered temperature. Once the thermal exchange media  34  passes through the coils of the second evaporator  22 , the thermal exchange media  34  is evaporated and more completely enters the gaseous state  94 . Accordingly, the inlet sensor  114  senses the temperature of the thermal exchange media  34  as it enters the second evaporator  22 , and the outlet sensor  118  senses the temperature of the thermal exchange media  34  as it exits the second evaporator  22 . Each of the inlet and outlet sensors  114 ,  118  are communicatively coupled to the controller  42 , such that the inlet and outlet temperatures of the thermal exchange media  34  are sent to the controller  42  for comparison. 
     The controller  42  is also communicatively coupled to the electronic expansion valve  26 . Accordingly, if the controller  42  detects that the difference in the inlet and outlet temperatures of the thermal exchange media  34  satisfy a set temperature for the adjustable cooling system  50 , then the controller  42  will send a corresponding signal to the electronic expansion valve  26 . The signal sent from the controller  42  to the electronic expansion valve  26  can result in an adjustment of the electronic expansion valve  26  where an adjusted difference in the inlet and outlet temperatures is desired. 
     In a non-limiting example, in condition A, if the temperature difference between the inlet and the outlet of the second evaporator  22  matches the set temperature of the refrigeration or freezer compartments, then the controller  42  typically sends a signal to the electronic expansion valve  26  to close. This is because the temperature in either the refrigeration or freezer compartment  62 ,  66  is sufficiently cooled as a result of the respective cycle. Additionally or alternatively, in condition B, the controller  42  typically sends a signal to the electronic expansion valve  26  to partially close, thereby reducing the amount of thermal exchange media  34  entering the second evaporator  22 . This occurs when the thermal exchange media  34  is approaching a temperature that correlates with the set temperature of the freezer compartment  34 , so the electronic expansion valve  26  can slow the entry of thermal exchange media  34  into the second evaporator  22  to regulate additional cooling of the freezer compartment  66 . 
     In condition C, the controller  42  typically sends a signal to the electronic expansion valve  26  to open further to allow more thermal exchange media  34  to enter the second evaporator  22 . This typically occurs during the refrigerating cycle  54  or during a pump-out cycle between the freezing and refrigerating cycles  58 ,  54 . 
     During the freezing cycle  58 , thermal exchange media  34  in the gaseous state  94  is retained in the pressure regulator  38 . To release the thermal exchange media  34  in the gaseous state  94  from the pressure regulator  38 , the refrigerating cycle  54  may be run, which will consequently push through any additional thermal exchange media  34  in the gaseous state  94 . It is also contemplated that there may be a separate cycle known as the pump-out cycle that flushes the adjustable cooling system  50 , and ultimately flushes the pressure regulator  38 , of remaining thermal exchange media  34  in the gaseous state  94  prior to starting a new refrigerating cycle  54 . 
     Once the thermal exchange media  34  is within the second evaporator  22 , it is typically evaporated entirely, or almost entirely, into the gaseous state  94  as the thermal exchange media  34  exits the second evaporator  22 . In the gaseous state  94  exiting the second evaporator  22 , the thermal exchange media  34  has a lowered pressure. The thermal exchange media  34  is then transferred to the compressor  14  that is fluidly coupled to the second evaporator  22  and the cycle begins again. 
     The compressor  14  may be an on/off compressor as is typically used in cooling systems, such as the adjustable cooling system  50 . In such configurations, the compressor  14  controls the temperature of the adjustable cooling system  50  to the extent that the compressor  14  restricts the flow of the thermal exchange media  34 . While the compressor  14  controls the temperature and pressure of the adjustable cooling system  50  to the extent that the compressor  14  is on or off, in such configurations the electronic expansion valve  26  is the primary regulator of the temperature and pressure within the adjustable cooling system  50 . Accordingly, the electronic expansion valve  26 , in combination with the signals received by the controller  42 , will adjust to being partially or fully open or closed depending on the cooling specifications of the adjustable cooling system  50 . 
     As mentioned above, it is also contemplated that the compressor  14  may be a variable speed compressor  14 . In such configuration, both the variable speed compressor  14  and the electronic expansion valve  26  will control the temperature of the adjustable cooling system  50 . For example, if the controller  42  receives a signal from the sensor  110  that the temperature of the adjustable cooling system  50  is higher than specified, then the controller  42  sends a signal to the variable speed compressor  14 , the electronic expansion valve  26 , or both. Either or both of the electronic expansion valve  26  and the variable speed compressor  14  operates to adjust the flow rate of the thermal exchange media  34 . By way of example, and not limitation, during the refrigerating cycle  54 , the variable speed compressor  14  can be used to adjust the rate at which the thermal exchange media  34  exits the variable speed compressor  14 . This adjustment of the rate can accommodate a specified temperature of the adjustable cooling system  50 . In combination with the variable speed compressor  14 , the electronic expansion valve  26  will also adjust the rate at which the thermal exchange media  34  flows through the adjustable cooling system  50 . Further, the electronic expansion valve  26  is communicatively coupled to the variable speed compressor  14  via the controller  42  to execute the adjustment. Ultimately, the controller  42 , based on signals received from the sensor  110 , communicates with the variable speed compressor  14  and the electronic expansion valve  26  to control the flow rate of the thermal exchange media  34 . 
     The combination of the variable speed compressor  14  and the electronic expansion valve  26  is advantageous for efficient performance over the adjustable cooling system  50 . The controller  42  sets the variable speed compressor  14  to a speed that will provide the most efficient cooling within the adjustable cooling system  50 . Additionally, the controller  42  may also adjust the electronic expansion valve  26  to operate so as to provide efficient cooling within the adjustable cooling system  50 . The sensors  114 ,  118  may also communicate directly with the electronic expansion valve  26 . Each of these adjustments result in the variable speed compressor  14  and the electronic expansion valve  26  operating at a specified speed or configuration as quickly as possible without the process of ramping up to the set speed or configuration. For example, the specified efficient speed for the variable speed compressor  14  may be a high speed. The controller  42  is configured to communicate with the variable speed compressor  14  to adjust to the high speed without first slowly ramping up to that higher speed. Similarly, the electronic expansion valve  26  can be adjusted from a fully closed position to an open position and any point in between (i.e. partially open) without first proceeding through various intermediary steps. 
     Conventional cooling systems may set a temperature, but it takes time to reach the set temperature. Thus, the process used by conventional cooling systems wastes energy and is ultimately inefficient. Moreover, conventional cooling systems typically utilize a compressor that only functions in the on/off configuration, such that the conventional compressor does not alter or adjust the rate at which a fluid may pass through the conventional cooling system. Moreover, such conventional compressors are typically combined with a capillary tube, not an electrical valve. 
     Accordingly, it is advantageous and increases the efficiency of the adjustable cooling system  50  to incorporate the variable speed compressor  14  and the electronic expansion valve  26  into the adjustable cooling system  50 . The variable speed compressor  14  helps regulate the rate at which the thermal exchange media  34  moves through the various components of the adjustable cooling system  50  by operating at a set speed to reach a set temperature. In addition, the electronic expansion valve  26  regulates the flow rate of the thermal exchange media  34  by adjusting the opening of the valve, thus, controlling the rate at which the thermal exchange media  34  enters the second evaporator  22 . It is also contemplated, for added efficiency, that the first valve  90  may also be constructed from an electronic valve similar to the electronic expansion valve  26  described herein and as mentioned above. 
     The invention disclosed herein is further summarized in the following paragraphs and is further characterized by combinations of any and all of the various aspects described therein. 
     According to one aspect of the present disclosure, an appliance includes a variable speed compressor. A first evaporator is operably coupled to the variable speed compressor. A second evaporator is operably coupled in series to the first evaporator. An electronic expansion valve is in fluid communication to the second evaporator and is configured to regulate a flow of thermal exchange media from the first evaporator to the second evaporator. 
     According to another aspect, an electronic expansion valve selectively expands a refrigerating fluid. The expanded refrigerating fluid is transferred to a second evaporator. 
     According to yet another aspect, an electronic expansion valve is positioned between and in series with a first evaporator and a second evaporator. 
     According to still another aspect, a pressure regulator is a flash chamber that is configured to separate a thermal exchange media in a gaseous state from the thermal exchange media in a liquid state. The separated liquid state is in fluid communication with an electronic expansion valve. 
     According to another aspect, an electronic expansion valve defines a first mode and a second mode. The first mode is a high flow state. The second mode is a low flow state. 
     According to another aspect, a controller is configured to switch an electronic expansion valve between a first mode and a second mode. 
     According to yet another aspect, a first evaporator, a pressure regulator, an electronic expansion valve, and a second evaporator is operably coupled in series. 
     According to another aspect of the present disclosure, a refrigeration system for an appliance includes a compressor and a first evaporator. A second evaporator is operably coupled to the first evaporator. An electronic expansion valve is configured to regulate a thermal exchange media from the first evaporator into the second evaporator. A pressure regulator is operably coupled to the electronic expansion valve and the first evaporator. A controller is configured to control the electronic expansion valve. 
     According to another aspect, a compressor is a variable speed compressor. 
     According to yet another aspect, a refrigeration system further includes a sensor that is communicatively coupled to a controller. The controller is configured to open or close an electronic expansion valve in response to a signal that is received from a sensor. 
     According to still another aspect, a sensor is a temperature sensor that is coupled to a tube positioned between a first evaporator and a second evaporator. 
     According to another aspect, an electronic expansion valve includes a plurality of rates. A controller is configured to adjust the electronic expansion valve to a corresponding rate of the plurality of rates in response to a signal from a sensor. 
     According to yet another aspect, a pressure regulator is a flash chamber that is configured to separate a thermal exchange media in a gaseous state from the thermal exchange media in a liquid state. The flash chamber is operably coupled in series to an electronic expansion valve. 
     According to still another aspect, an electronic expansion valve is fluidly coupled to a first evaporator and a second evaporator to regulate the flow of a thermal exchange media to the second evaporator in response to a controller. 
     According to yet another aspect of the present disclosure, a refrigeration system includes a variable speed compressor and a first evaporator. A second evaporator is operably coupled in series with the first evaporator. A first valve is coupled to the variable speed compressor and the first evaporator. A second valve is fluidly coupled to the second evaporator, and a pressure regulator is coupled to the second valve. 
     According to another aspect, a second valve is an electronic expansion valve that is communicatively coupled to a controller. 
     According to yet another aspect, a refrigeration system further includes a sensor that is communicatively coupled to a controller. The controller receives a signal from a sensor and adjusts an electronic expansion valve in response to the signal. 
     According to still another aspect, a variable speed compressor is in communication with a controller and is configured to regulate a flow rate of a thermal exchange media in response to a signal that is received by the controller. 
     According to another aspect, a pressure regulator and a second valve are operably coupled to and positioned in series between a first valve and a second evaporator. 
     According to another aspect, a second valve includes a first mode and a second mode. The first mode is a high flow state, and a second mode is a low flow state. 
     It will be understood by one having ordinary skill in the art that construction of the described disclosure and other components is not limited to any specific material. Other exemplary embodiments of the disclosure disclosed herein may be formed from a wide variety of materials, unless described otherwise herein. 
     For purposes of this disclosure, the term “coupled” (in all of its forms, couple, coupling, coupled, etc.) generally means the joining of two components (electrical or mechanical) directly or indirectly to one another. Such joining may be stationary in nature or movable in nature. Such joining may be achieved with the two components (electrical or mechanical) and any additional intermediate members being integrally formed as a single unitary body with one another or with the two components. Such joining may be permanent in nature or may be removable or releasable in nature unless otherwise stated. 
     It is also important to note that the construction and arrangement of the elements of the disclosure as shown in the exemplary embodiments is illustrative only. Although only a few embodiments of the present innovations have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited. For example, elements shown as integrally formed may be constructed of multiple parts or elements shown as multiple parts may be integrally formed, the operation of the interfaces may be reversed or otherwise varied, the length or width of the structures and/or members or connector or other elements of the system may be varied, the nature or number of adjustment positions provided between the elements may be varied. It should be noted that the elements and/or assemblies of the system may be constructed from any of a wide variety of materials that provide sufficient strength or durability, in any of a wide variety of colors, textures, and combinations. Accordingly, all such modifications are intended to be included within the scope of the present innovations. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the desired and other exemplary embodiments without departing from the spirit of the present innovations. 
     It will be understood that any described processes or steps within described processes may be combined with other disclosed processes or steps to form structures within the scope of the present disclosure. The exemplary structures and processes disclosed herein are for illustrative purposes and are not to be construed as limiting.