Patent Publication Number: US-11391501-B2

Title: Modulator for an ice maker

Description:
FIELD OF THE INVENTION 
     The present subject matter relates generally to ice makers for appliances. 
     BACKGROUND OF THE INVENTION 
     Certain consumers find clear ice preferable to cloudy ice. In clear ice formation processes, dissolved solids typically found within water, e.g., tap water, are separated out and essentially pure water freezes to form the clear ice. Since the water in clear ice is purer than that found in typical cloudy ice, clear ice is less likely to affect drink flavors. Clear ice is popular for serving with high end drinks due to its aesthetic appearance and reduced impurities. At certain high end bars, a popular clear ice offering is a single large clear ice sphere. 
     A longstanding customer desire is an ice maker that can produce clear ice, in particular single large clear ice spheres, economically. 
     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 a first example embodiment, an icemaker appliance includes a cabinet. A refrigeration system includes a compressor, a condenser, an expansion device, and an evaporator. The refrigeration system is charged with a refrigerant. The refrigeration system further includes a modulator having a reservoir and a supply conduit. The reservoir of the modulator is positioned on an outlet conduit of the evaporator. A first end portion of the supply conduit is coupled to an inlet conduit of the evaporator, and a second end portion of the supply conduit is coupled to the reservoir of the modulator. The refrigerant is flowable into and out of the reservoir of the modulator through the supply conduit of the modulator. An ice maker is positioned within the cabinet. The evaporator of the refrigeration system is coupled to the icemaker such that the refrigeration system is operable to chill the icemaker. 
     In a second example embodiment, an icemaker appliance includes a cabinet. A refrigeration system includes a compressor, a condenser, an expansion device, and an evaporator. The refrigeration system is charged with a refrigerant. The refrigeration system further includes a modulator having a reservoir and a supply conduit. The reservoir of the modulator is positioned on an outlet conduit of the evaporator. A first end portion of the supply conduit is coupled to an inlet conduit of the evaporator, and a second end portion of the supply conduit is coupled to the reservoir of the modulator. The refrigerant is flowable into and from the reservoir of the modulator through the supply conduit of the modulator. The refrigerant within the reservoir of the modulator is in thermal communication with the refrigerant within the outlet conduit of the evaporator. The modulator is configured for varying a volume of the refrigerant that flows through the refrigeration system in response to the temperature of the refrigerant within the outlet conduit of the evaporator. An ice maker is positioned within the cabinet. The evaporator of the refrigeration system is coupled to the ice maker such that the refrigeration system is operable to chill the ice maker. 
     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  is a front, perspective view of an icemaker appliance according to an example embodiment of the present subject matter. 
         FIG. 2  is a front, perspective view of the example icemaker appliance of  FIG. 1  with a door of the example icemaker appliance shown in an open position. 
         FIG. 3  is a schematic view of certain components of the example icemaker appliance of  FIG. 1 . 
         FIG. 4  is a schematic view of a modulator of the example icemaker appliance of  FIG. 1 . 
         FIG. 5  is a schematic view of an ice maker of the example 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. 
       FIGS. 1 and 2  provide front, perspective views of an icemaker appliance  100  according to an example embodiment of the present subject matter. As discussed in greater detail below, icemaker appliance  100  includes features for generating or producing clear ice, such as clear ice billets. Thus, a user of icemaker appliance  100  may consume clear ice produced within icemaker appliance  100 . As may be seen in  FIG. 1 , icemaker appliance  100  defines a vertical direction V. 
     Icemaker appliance  100  includes a cabinet  110 . Cabinet  110  may be insulated in order to limit heat transfer between an interior volume  111  ( FIG. 2 ) of cabinet  110  and ambient atmosphere. Cabinet  110  extends between a top portion  112  and a bottom portion  114 , e.g., along the vertical direction V. Thus, top and bottom portions  112 ,  114  of cabinet  110  are spaced apart from each other, e.g., along the vertical direction V. A door  119  is mounted to cabinet  110  at a front portion of cabinet  110 . Door  119  permits selective access to interior volume  111  of cabinet  110 . For example, door  119  is shown in a closed position in  FIG. 1 , and door  119  is shown in an open position in  FIG. 2 . A user may rotate door between the open and closed positions to access interior volume  111  of cabinet  110 . 
     As may be seen in  FIG. 2 , various components of icemaker appliance  100  are positioned within interior volume  111  of cabinet  110 . In particular, icemaker appliance  100  includes an ice maker  120  disposed within interior volume  111  of cabinet  110 , e.g., at top portion  112  of cabinet  110 . Ice maker  120  is configured for producing clear ice I. Ice maker  120  may be configured for making any suitable type of clear ice. For example, ice maker  120  may be a billet-style ice maker, and the billet clear ice from ice maker  120  may be shaped into large clear ice spheres. 
     Icemaker appliance  100  also includes an ice storage compartment or storage bin  102 . Storage bin  102  is disposed within interior volume  111  of cabinet  110 . In particular, storage bin  102  may be positioned, e.g., directly, below ice maker  120  along the vertical direction V. Thus, storage bin  102  is positioned for receiving clear ice I from ice maker  120  and is configured for storing the clear ice I therein. It will be understood that storage bin  102  may be maintained at a temperature less than the freezing point of water. In alternative example embodiments, storage bin  102  may be maintained at a temperature greater than the freezing point of water. Thus, the clear ice I within storage bin  102  can melt over time while stored within storage bin  102 . A control panel  192  on cabinet  110  allows a user to regulate operation of icemaker appliance  100 . 
       FIG. 3  is a schematic view of certain components of icemaker appliance  100 . As may be seen in  FIG. 3 , icemaker appliance  100  includes a refrigeration system  125  with components for executing a known vapor compression cycle for chilling water within ice maker  120  to form the clear ice I. The components of refrigeration system  125  include a compressor  130 , a condenser  140 , an expansion device  150 , and an evaporator  160  connected in series and charged with a refrigerant. As will be understood by those skilled in the art, refrigeration system  125  may include additional components, e.g., at least one additional evaporator, compressor, expansion device, and/or condenser. As an example, refrigeration system  125  may include two evaporators. 
     Within refrigeration system  125 , refrigerant flows into compressor  130 , 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  140 . Within condenser  140 , heat exchange with ambient air takes place so as to cool the refrigerant. A fan  142  is used to pull air across condenser  140  so as to provide forced convection for a more rapid and efficient heat exchange between the refrigerant within condenser  140  and the ambient air. Thus, as will be understood by those skilled in the art, increasing air flow across condenser  140  can, e.g., increase the efficiency of condenser  140  by improving cooling of the refrigerant contained therein. 
     An expansion device (e.g., a valve, capillary tube, or other restriction device)  150  receives refrigerant from condenser  140 . From expansion device  150 , the refrigerant enters evaporator  160 . Upon exiting expansion device  150  and entering evaporator  160 , the refrigerant drops in pressure. Due to the pressure drop and/or phase change of the refrigerant, evaporator  160  is cool relative to ice maker  120 , e.g., water within ice maker  120 . As such, water within ice maker  120  may freeze to form the clear ice I. Thus, evaporator  160  is a type of heat exchanger which transfers heat from water within ice maker  120  to refrigerant flowing through evaporator  160 . 
     Refrigeration system  125  may also include a bypass valve  135  and a bypass conduit  137 . Bypass valve  135  may be a servo motor driven bypass valve that is operable to directing hot gaseous refrigerant from compressor  130  to evaporator  160  through bypass conduit  137 . Thus, bypass valve  135  may direct all or a portion of the gaseous refrigerant flowing between compressor  130  and condenser  150  into bypass conduit  137 . By flowing through bypass valve  135 , the refrigerant within bypass valve  135  does not flow through and bypasses condenser  140  and/or expansion device  150 . 
     Bypass valve  135  and bypass conduit  137  may provide a mechanism for implementing a hot gas bypass for ice harvest at evaporator  160 . As discussed in greater detail below, evaporator  160  may be coupled to ice maker  120  ( FIG. 2 ) and refrigerant flowing through evaporator  160  may transfer heat with water in ice maker  120 . When bypass valve  135  directs all or a portion of the gaseous refrigerant flowing between compressor  130  and condenser  150  into bypass conduit  137 , the hot refrigerant flowing into evaporator  160  from bypass conduit  137  may partially melt ice within ice maker  120  to assist with harvesting the ice from ice maker  120 . 
     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 freeze water within ice maker  120 . The refrigeration system  125  depicted in  FIG. 3  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. 
     Refrigeration system  125  also includes a modulator  200 . Modulator  200  is configured for adjusting the charge of refrigerant flowing within refrigeration system  125 , as discussed in greater detail below. As shown in  FIG. 3 , modulator  200  includes a reservoir  210  and a supply conduit  220 . Reservoir  210  is positioned on an outlet conduit  164  of evaporator  160 . The outlet conduit  164  of evaporator  160  may extend from evaporator  160 , and refrigerant exiting evaporator  160  may flow through outlet conduit  164  towards compressor  130 . In contrast, an inlet conduit  162  of evaporator  160  may extend to evaporator  160 , and refrigerant flowing from expansion device  150  may flow through outlet conduit  164  into evaporator  160 . 
     Supply conduit  220  extends between and connects reservoir  210  and inlet conduit  162  of evaporator  160 . Thus, refrigerant at inlet conduit  162  of evaporator  160  may flow into reservoir  210  via supply conduit  220 . In addition, refrigerant within reservoir  210  may flow into inlet conduit  162  of evaporator  160  via supply conduit  220 . Thus, refrigerant is flowable into and from reservoir  210  through supply conduit  220 . As discussed in greater detail below, modulator  200  may draw refrigerant from inlet conduit  162  into reservoir  210  via supply conduit  220  or may supply refrigerant from reservoir  210  into inlet conduit  162  via supply conduit  220 , e.g., based on the temperature of refrigerant within outlet conduit  164  of evaporator  160 . 
       FIG. 4  is a schematic view of modulator  210 . As shown in  FIG. 4 , supply conduit  220  may extend between a first end portion  222  and a second end portion  224 . First end portion  222  of supply conduit  220  may be coupled to inlet conduit  162  ( FIG. 3 ). Thus, refrigerant from inlet conduit  162  may enter supply conduit  220  at first end portion  222  of supply conduit  220 . Similarly, refrigerant from reservoir  210  may exit supply conduit  220  and enter inlet conduit  162  at first end portion  222  of supply conduit  220 . Second end portion  224  of supply conduit  220  may be coupled to reservoir  210 . Thus, refrigerant from reservoir  210  may enter supply conduit  220  at second end portion  224  of supply conduit  220 . Similarly, refrigerant from inlet conduit  162  may exit supply conduit  220  and enter reservoir  210  at second end portion  224  of supply conduit  220 . Reservoir  210  may extend between a top portion  214  and a bottom portion  216 , and second end portion  224  of supply conduit  220  may be positioned at bottom portion  216  of reservoir  210 . Thus, e.g., refrigerant may enter and exit supply conduit  220  at bottom portion  216  of reservoir  210 . 
     As noted above, reservoir  210  is positioned on outlet conduit  164 . In particular, reservoir  210  may be positioned on outlet conduit  164  such that outlet conduit  164  is positioned concentrically with an interior volume  212  of reservoir  210 . Thus, e.g., refrigerant within interior volume  212  of reservoir  210  may contact outlet conduit  164 . To mount reservoir  210  on outlet conduit  154 , reservoir  210  may be soldered to outlet conduit  154 . For example, top and bottom portions  214 ,  216  of reservoir  210  may be soldered to outlet conduit  154 . In alternative example embodiments, outlet conduit  154  may be positioned on an exterior surface of reservoir  210 , e.g., such that outlet conduit  154  is positioned outside of interior volume  212  of reservoir  210 . In particular, outlet conduit  154  may be soldered to the exterior surface of reservoir  210 . In such example embodiments, heat transfer between refrigerant within reservoir  210  and refrigerant within outlet conduit  154  may be limited compared to the example arrangement shown in  FIG. 4 . 
     Supply conduit  220  provides a flow path for refrigerant in refrigeration system  125  to flow into and out of reservoir  210 . In particular, modulator  200  may form a dead end branch for refrigerant within refrigeration system  125 . Thus, interior volume  212  of reservoir  210  may not be in direct fluid communication with the interior of outlet conduit  164 , and, while refrigerant (labeled L in  FIG. 4 ) within interior volume  212  of reservoir  210  can contact an exterior of outlet conduit  164 , the refrigerant L within interior volume  212  of reservoir  210  cannot flow directly into outlet conduit  164 , e.g., without exiting reservoir  210  via supply conduit  220 . While not able to bypass evaporator  160  via modulator  200 , the refrigerant L within interior volume  212  may exchange heat with refrigerant within outlet conduit  164 , as discussed in greater detail below. 
     Interior volume  212  of reservoir  210  may be sized to contain a suitable volume of refrigerant. For example, interior volume  212  of reservoir  210  may be sized to contain no less than five cubic centimeters (5 cm 3 ) of refrigerant and no more than a half of a liter (0.5 L) of refrigerant. As noted above, modulator  200  may draw refrigerant from inlet conduit  162  into reservoir  210  via supply conduit  220  or may supply refrigerant from reservoir  210  into inlet conduit  162  via supply conduit  220 . The above recited sizing of reservoir  210  may advantageously allow a desirable volume of refrigerant to be stored within reservoir  210 , e.g., and thus not be cycled through refrigeration system  125 . By sizing interior volume  212  of reservoir  210  to store a suitable volume of refrigerant, the above recited sizing of reservoir  210  may advantageously allow modulator  200  to vary the volume of refrigerant flowing through refrigeration system  125 . 
       FIG. 5  is a schematic view of ice maker  120  of icemaker appliance  100 . Refrigeration system  125  may be operable to chill ice maker  120 , in particular water within ice maker  120 , to form the clear ice I within ice maker  120 . Thus, as may be seen in  FIG. 5 , evaporator  160  may be coupled to ice maker  120 . In particular, ice maker  120  may be a billet ice maker with a plurality of mold bodies  170 , a plurality of spray nozzles  172 , and a pump  174 . 
     Evaporator  160  may include a plurality of coils  168 , and each coil  168  may be positioned at a top portion of a respective mold body  170 . Each spray nozzle  172  is positioned and oriented towards a respective mold body  172 . Pump  174  is operable to flow water W from a reservoir  176  through nozzles  172  towards mold bodies  170 . As pump  174  flows water W into mold bodies  170 , refrigerant flowing through coils  168  freezes the water W to form clear ice billets within molds  170 . 
     Mold bodies  170  may be sized to form suitable clear ice billets. For example, each mold body  170  may be sized for forming an ice billet having a width of about three inches (3″). The above recite sizing of mold bodies  170  may advantageously provide a large ice billet, e.g., suitable for formation into a spherical clear ice cube. In alternative example embodiments, each mold body  170  may be sized for forming an ice billet having a width of about one inch (1″) or about two inches (2″). As used herein, the term “about” means within half an inch (0.5″) of the stated width when used in the context of widths. 
     Operation of modulator  210  to regulate the volume of refrigerant flowing through refrigeration system  125  will now be described in greater detail below. When icemaker appliance  100  begins an ice formation cycle to form clear ice I with ice maker  120 , room temperature water may be sprayed into mold bodies  170  through nozzles  172 . Evaporator  160  is in thermal communication with mold bodies  170 , and an evaporation temperature of the refrigerant within evaporator  160  may be about forty degrees Fahrenheit (40° F.) at the start of the ice formation cycle when the room temperature water is sprayed into mold bodies  170 . As used herein the term “about” means within five degrees of the stated temperature when used in the context of temperatures. As the water is chilled and ice begins to form within mold bodies  170 , the evaporator temperature drops to below freezing, i.e., thirty-two degrees Fahrenheit (32° F.). By the time, ice formation cycle is complete and a large, e.g., three inch, billet is formed within mold bodies  170 , the evaporator temperature may be as cold as negative twenty degrees Fahrenheit (−20° F.). 
     Because the temperature of the refrigerant within evaporator  160  can vary dramatically between the beginning and the end of the ice formation cycle, the optimum charge of refrigerant to fully flood evaporator  160  constantly changes. As the evaporator temperature and pressure drops, so does the amount of refrigerant required to fully flood evaporator  160 . Modulator  200  is configured to regulate the charge of refrigerant flowing through refrigeration system  125 , e.g., and provide an optimum charge in evaporator  160  throughout the ice making cycle. 
     When evaporator  160  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  162 , i.e., the evaporator inlet temperature, due to the pressure drop of refrigerant within evaporator  160 . Such temperature differential between the evaporator outlet and inlet temperatures causes refrigerant within inlet conduit  162  to migrate towards interior volume  212  of reservoir  210  via supply conduit  220 . Within interior volume  212  of reservoir  210 , the refrigerant from inlet conduit  162  condenses and is stored, e.g., until evaporator  160  is not fully flooded. 
     When evaporator  160  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  212  of reservoir  210  and thereby increase the vapor pressure of the refrigerant L within interior volume  212  of reservoir  210 . When the vapor pressure of the refrigerant L is greater than the vapor pressure of refrigerant in inlet conduit  162 , refrigerant L within reservoir  210  migrates towards inlet conduit  162  and back into refrigeration system  125  via supply conduit  220 . 
     As may be seen from the above, modulator  200  moves refrigerant into and out of refrigeration system  125  based on the evaporator outlet temperature. Modulator  200  may advantageously be a passive system without moving parts. Thus, e.g., modulator  200  may regulate the charge of refrigeration system  125  based entirely on thermodynamics and vapor pressure, e.g., and without require sensors, control valves, etc. When evaporator  160  is low on charge, e.g., as can happen at the beginning of an ice making cycle 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  200  back out into refrigeration system  125 , e.g., into evaporator  160 . Conversely, when the evaporator outlet temperature is low due to evaporator  160  being fully flooded, the evaporator outlet temperature is less than the evaporator inlet temperature due to the pressure drop through evaporator  160 . Such temperature differential drives refrigerant to migrate from inlet conduit  162  into modulator  200 . 
     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.