Patent Publication Number: US-7908873-B1

Title: Minimized insulation thickness between high and low sides of cooling module set utilizing gas filled insulation panels

Description:
BACKGROUND OF THE PRESENT INVENTION 
     The present invention generally relates to a cooling system and an active insulation system that are supported by a single compressor. 
     SUMMARY OF THE INVENTION 
     In one aspect of the present invention, a variable refrigeration system includes a cooling system having a compressor, a condenser, and a refrigerant. An active insulation system includes an insulation portion disposed therein that holds a gas. The insulation portion is operably connected to the compressor and includes an insulation panel adjacent a refrigerated compartment. A controller is operably connected to the cooling system and to the active insulation system. The controller operates between a first stage, wherein the controller sends a signal to the compressor to compress the refrigerant in the cooling system, and a second stage, wherein the controller sends a signal to the compressor to alter the gas content in the insulation portion of the active insulation system. 
     In another aspect of the present invention, a refrigerator includes a cooling system having a compressor, a condenser, and a refrigerant. An active insulation system includes an insulation portion with a gas disposed therein. The insulation portion is operably connected to the compressor. A controller is operably connected to the cooling system and to the active insulation system. The controller operates between a first stage, wherein the controller sends a signal to the cooling system to compress the refrigerant, and a second stage, wherein the controller sends a signal to the compressor to alter the gas content in the insulation portion. 
     In yet another aspect of the present invention, a method of operating a refrigerator includes providing a cooling system having a compressor, a condenser, a fan, and a refrigerant. An active insulation system is provided, which includes an insulation portion operably connected to the compressor. A controller is operably connected to the cooling system and to the active insulation system. The controller is set to operate in a first stage to send a signal to the compressor to compress the refrigerant. The controller is set to operate in a second stage to send a signal to the compressor to alter the gas content in the insulation portion. 
     These and other features, advantages and objects of the present invention will be further understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic drawing of one embodiment of a refrigeration system of the present invention; 
         FIG. 2  is an enlarged partial schematic view of the active insulation system of the present invention; 
         FIG. 3  is a schematic drawing of one embodiment of a variable refrigeration system of the present invention; 
         FIG. 4  is a front elevational view of a compressor and evaporator used in one embodiment of the variable refrigeration system; and 
         FIG. 5  is a top perspective view of a compressor used in one embodiment of the variable refrigeration system. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     For purposes of description herein the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented in  FIG. 1 . However, it is to be understood that the invention may assume various alternative orientations and step sequences, 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. 
     Referring to  FIGS. 1 and 2 , the reference numeral  10  in the illustrated embodiment generally designates a variable refrigeration system including a cooling system  12  having a compressor  14 , a condenser  16 , and a refrigerant  18 . An active insulation system  20  includes an insulation portion  22  disposed therein that holds a gas  24 . The insulation portion  22  is operably connected to the compressor  14 . A controller  26  is operably connected to the cooling system  12  and to the active insulation system  20 . The controller  26  operates between a first stage, wherein the controller  26  sends a signal to the compressor  14  to compress the refrigerant  18  in the cooling system  12 , and a second stage, wherein the controller  26  sends a signal to the compressor  14  to alter the gas content in the insulation portion  22  of the active insulation system  20 . 
     The variable refrigeration system  10  is designed for use in a refrigerator  36  or other atmosphere conditioning appliance having several walls  37  and at least one door  38 . At least one insulation portion  22  is disposed in at least one wall  37  or door  38 . Each insulation portion  22  includes at least one vacuum insulation panel  50 . The refrigerator  36  shown in  FIG. 1  includes a side-by-side door configuration, however, it is contemplated that any door configuration with any number of storage compartments  42  may be used in conjunction with the variable refrigeration system  10 , as explained in detail below. 
     Referring now to the embodiment illustrated in  FIG. 1 , the cooling system  12  of the variable refrigeration system  10  acts to cool the interior storage compartments  42  of the refrigerator  36 . The controller  26  is operably connected with the cooling system  12  and sends a signal to the compressor  14  to compress the refrigerant gas  18  when the temperature in the storage compartments  42  has exceeded a predetermined maximum temperature mark. When the compressor  14  activates, the compressor  14  forces the refrigerant  18  into a pressure line  51 . The pressure and temperature of the refrigerant  18  increase during compression. The resulting hot, high pressure refrigerant  18  is gaseous at this point and is then condensed to a liquid in the air cooled condenser  16 . The condensers  16  are heat exchanging coils and are disposed outside the refrigerator  36  (sometimes on a rear side of the refrigerator  36 ), and allow the refrigerant  18  to dissipate the heat of pressurization. As the refrigerant  18  cools, the refrigerant  18  maintains liquid form through a filter-dryer  40  (where moisture is absorbed by silica gels and non-condensable gases are bound by getters, such as highly active calcium oxide) and into an expansion device  41 . 
     Referring again to  FIG. 1 , when the refrigerant  18  flows through the expansion device  41 , the liquid refrigerant  18  moves from a high pressure state to a low pressure state, such that the refrigerant  18  expands and evaporates in an evaporator  44  adjacent the interior storage compartments  42  of the refrigerator  36 . When the refrigerant  18  evaporates, the refrigerant  18  becomes very cool and absorbs heat from the interior storage compartments  42  of the refrigerator  36 , thereby making the interior storage compartments  42  cold. The refrigerant  18  then flows back through the suction line  45 . A valve  43  connects the compressor  14  with a refrigeration suction line  45  and an insulation suction line  49 . During operation of the cooling system  12 , the valve  43  is open to the refrigeration suction line  45 , but closed to the insulation suction line  49 . Accordingly, the refrigerant  18  flows past the valve  43  and insulation suction line  49  back to the compressor  14  to be compressed again and the cycle continues. Through this entire refrigeration process, the system valve  43  remains closed to the active insulation system  20  but open to the cooling system  12 . Accordingly, the compressor  14  draws suction from line  45  but not line  49 . 
     Referring now to  FIGS. 1 and 2 , the controller  26  communicates with valve  43  and when the insulation portion  22  in the walls  37  or doors  38  of the refrigerator  36  have become depressurized or reached a predetermined pressure, the controller  26  closes valve  43  to line  45  and opens valve  43  to line  49 . When the compressor  14  activates, the gas  24  that is inside the insulation portion  22 , and specifically, the vacuum insulation panels  50 , is withdrawn, thus decreasing the thermal conductivity of each vacuum insulation panel  50 . After the vacuum insulation panels  50  have reached a predetermined depressurization level, the valve  43  again closes to line  49  and opens to line  45  so that the cooling system  12  can once again operate. It is conceived that the valve  43  may be the only valve in the active insulation system  20  such that when the compressor  14  activates and the valve  43  is opened to line  49 , all insulation portions  22  in the refrigerator  36  are depressurized by the compressor  14 . It is also conceived that the valve  43  may be a master valve that allows suction of line  49  but not individual vacuum insulation panels  50 . Line  49  connects with a series of control valves  56  in a manifold valving system  54 . Each vacuum insulation panel  50  that has an open control valve  56  will be depressurized by way of line  49 . However, those vacuum insulation panels  50  that have closed control valves  56  will not be depressurized. The controller  26  will determine which vacuum insulation panels  50  should be depressurized and which should not. It is conceived that sensors disposed at or near valves  56  will measure the pressure level in each line  58  and relay the information to the controller  26 , which then determines which control valves  56  should be opened for additional depressurization and which control valves  56  should remain closed because the current depressurization in those vacuum insulation panels  50  are adequate. It will be understood by one having ordinary skill in the art that the embodiment illustrated in  FIG. 1  is a closed system variable refrigeration system  10  that includes an active insulation system  20  and a cooling system  12 . Neither liquid nor gas is expelled to the environment. It will also be understood that a hybrid system that operates both the cooling system  12  and active insulation system  20  simultaneously may be constructed. 
     As shown in  FIG. 3 , another embodiment of the variable refrigeration system  10  is illustrated that operates as an open system. The controller  26  is connected to the manifold valving system  54  by way of a signal line  57 . The cooling system  12  of this embodiment operates in a similar manner to the cooling system  12  discussed in the previous embodiment. However, the cooling system  12  shown in the embodiment of  FIG. 3  includes a release valve  43 ′. When the cooling system  12  is in operation, the release valve  43 ′ is open to pressure line  51 , but closed to a containment line  59 . 
     Referring again to  FIG. 3 , the controller  26  may send a signal to the compressor  14  to alter the content of the gas  24  in the insulation portion  22  of the active insulation system  20 . During this stage, when the vacuum insulation panel  50  has reached a predetermined maximum pressure level due to diffusion of atmospheric gases (air) into the vacuum insulation panel  50 , the valve  43  is closed to the line  45  and opened to the line  49 . The compressor  14  is activated and acts as a vacuum that evacuates the gas  24  through the line  49  past the valves  56  and from the panel lines  58  in the direction of arrows  47  ( FIG. 2 ). The manifold valving system  54  includes at least one and possibly several control valves  56 . Panel line  58  extends from each valve  56  and connects to the vacuum insulation panel  50  disposed in at least one wall  37  or door  38  of the refrigerator  36 . The gas  24  is removed from each vacuum insulation panel  50  that has an open control valve  56 . The valves  56  on the manifold valving system  54  are designed to allow transfer of the refrigerant  18  between the active insulation system  20  and the cooling system  12  at varying rates. Those vacuum insulation panels  50  that have closed valves  56  are not depressurized. It is contemplated that the vacuum insulation panels  50  could be filled with a porous insulation material that acts as a filler for the volume of the vacuum insulation panel  50 . The insulation material may be any of several possible insulation materials, including, but not limited to, fiberglass, vermiculate, and open-celled foam. When the gas  24  is evacuated from the vacuum insulation panel  50 , a low K-factor (high R-value) insulation panel  50  is created as the gas  24  content is lowered. Unlike the previously discussed embodiment, this embodiment is an open system that allows vacuumed air from the vacuum insulation panels  50  to be released to the environment. After the gas  24  has been evacuated, the gas  24  is forced out of the variable refrigeration system  10  and into a containment unit  53  through the release valve  43 ′ for disposal or expelled out into the atmosphere through a release line  60 . Although only this configuration of components is illustrated, one having skill in the art will appreciate and recognize that various other configurations are possible. 
     Referring again to the embodiment illustrated in  FIGS. 1 and 3 , the gas  24  and the refrigerant  18  may be the same and used interchangeably. Specifically, the refrigerant  18  is used as the gas  24  and is in fluid communication with the cooling system  12 , as well as the active insulation system  20 . Accordingly, the refrigerant  18  is used in both systems  12 ,  20  to maintain cold storage in compartments  42  in the refrigerator  36 , and flows through the line  49  typically in the direction of arrows  47  ( FIG. 3 ) from the vacuum insulation panels  50  to change the thermal conductivity of the vacuum insulation panels  50  in the walls  37  of the refrigerator  36 . When refrigerant  18  is vacuumed from the vacuum insulation panel  50 , the R-value or thermal resistance of the vacuum insulation panel  50  increases, thereby decreasing heat gain to the selected compartments  42  of the refrigerator  36 . The refrigerant  18  may be pumped from a refrigerant reservoir that stores the refrigerant  18  prior to use. The refrigerant  18  may be any one of HFC-245FA, isobutene, carbon dioxide, C-Pentane, or any of many other possible refrigerants. It is contemplated that a lower R-value would be desirable for storing wines, cheeses, or other foods that may require a higher temperature and humidity than is typically used for refrigeration of dairy and meats. 
     In the embodiment of  FIG. 3 , it is contemplated that the controller  26  can send a signal to the compressor  14  to allow ambient temperature gas to enter the vacuum insulation panel  50  through valves  43  and  43 ′. When the ambient temperature gas is supplied to the vacuum insulation panel  50 , the walls  37  or doors  38  of the refrigerator  36  raise in temperature, which assists in defrosting of the refrigerator  36 . Conversely, as disclosed above, the controller  26  can be used to send a signal to the compressor  14  to withdraw warm gas or air from the vacuum insulation panel  50 , thereby lessening heat gain to the interior walls  37  of the refrigerator  36 . Alternatively, the gas  24  can be allowed to bleed into the vacuum insulation panels  50 , thereby lessening heat gain of the interior walls  37  that house the vacuum insulation panels  50 . This function is utilized during a cooling operation or refrigeration of the interior storage compartments  42  of the refrigerator  36 . 
     As shown in  FIGS. 2 and 3 , the use of manifold valving system  54  allows control over each individual vacuum insulation panel  50 . Accordingly, each vacuum insulation panel  50  can be individually adjusted by operation of the compressor  14  based on signals sent by the controller  26  to each valve  56  of the manifold valving system  54 . For example, the controller  26  may send a signal to the compressor  14  and valves  43  and  43 ′ to bleed a warm gas  24 , such as ambient air, to vacuum insulation panels  50  in one or more walls  37  of a freezer unit to assist in defrosting of the freezer compartment. At the same time, the controller  26  may instruct the compressor  14 , after warming the freezer storage compartment, to pump refrigerant  18  from one or more walls  37  adjacent to the refrigerating storage compartment  42 . One having ordinary skill in the art will appreciate that any number of possibilities may exist for warming or cooling various walls  37  of the refrigerator  36  at a given time. 
     Referring now to  FIGS. 4 and 5 , the compressor  14  is connected to the evaporator  44  by way of a suction line  72 . The suction line  72  extends through or adjacent the vacuum insulation panel  50  disposed between the evaporator  44  and the compressor  14 . The vacuum insulation panel  50  thermal conductivity can be modified to allow heat from the compressor  14  to dissipate into an evaporator plenum  74  that holds or houses the evaporator  44  during defrosting. During cooling, a fan  76  disposed adjacent the evaporator coils  78  assists in transferring heat to the coils  78  to provide efficient evaporation of refrigerant  18  in the cooling system  12  and subsequent removal of heat from the refrigerated space. 
     As shown in  FIG. 5 , the illustrated embodiment of a linear compressor includes a pressure vessel  80  that is evacuated by way of a compressor piston  82 . A linear motor system  84  is disposed adjacent to the compressor piston  82  and motivates the same to create a relative vacuum in the pressure vessel  80 . It is conceived that any of a variety of compressors  14  could be used to facilitate compression of the refrigerant  18 , however, vacuuming the gas  24  out of the vacuum insulation panels  50  is benefited by the illustrated compressor  14  not requiring oil carried by the refrigerant  18  to lubricate the compressor  14  moving components. The linear compressor  14  illustrated in  FIG. 5  is able to operate without oil, utilizing a gas bearing as the piston-cylinder lubricant. Without the need for oil, the compressor  14  can be used to compress refrigerant gas  18  or act as a vacuum pump for refrigerant or air. 
     One embodiment of a method of operating the refrigerator  36  includes providing the cooling system  12  with the compressor  14 , the condenser  16 , the fan  76 , and the refrigerant  18 . The active insulation system  20  is provided and includes the insulation portion  22 , which is operably connected with the compressor  14 . The controller  26  is operably connected to the cooling system  12  and to the active insulation system  20 . The controller  26  is set to operate in a first stage to send a signal to the compressor  14  to compress the refrigerant  18 . In addition, the controller  26  is set to operate in a second stage to send a signal to the compressor  14  to alter the gas  24  content in the insulation portion  22 . 
     The above description is considered that of the illustrated embodiments only. Modifications of the invention will occur to those skilled in the art and to those who make or use the invention. Therefore, it is understood that the embodiments shown in the drawings and described above is merely for illustrative purposes and not intended to limit the scope of the invention, which is defined by the following claims as interpreted according to the principles of patent law, including the Doctrine of Equivalents.