Patent Publication Number: US-11029071-B2

Title: Refrigerator

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of U.S. patent application Ser. No. 15/247,431, filed Aug. 25, 2016, which claims the benefit of Korean Patent Application No. 10-2015-0121602, filed on Aug. 28, 2015 and No. 10-2015-0183473 filed on Dec. 22, 2015 in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Field 
     Embodiments of the present disclosure relate to a refrigerator capable of delaying an increase of a temperature of a storage compartment by allowing a temperature of air that is heated by a defrost heater to be lowered and then discharged to the storage compartment. 
     2. Description of the Related Art 
     In general, a refrigerator is an apparatus configured to keep foods fresh while having a storage compartment and a cool air supplying apparatus to supply cool air to the storage compartment. 
     A temperature of the storage compartment is maintained in a certain range that is required to keep foods fresh. 
     The storage compartment of the refrigerator has an open front surface, and the opened front surface is usually closed by a door to maintain the temperature of the storage compartment. 
     The storage compartment is divided into a freezing compartment in the right side and a refrigerating compartment in the left side by a partition, and the freezing compartment and the refrigerating compartment are closed by a freezing compartment door and a refrigerating compartment door. 
     The inside of the storage compartment maintains a temperature thereof by receiving a cool air from a cool air supplying device, and the cool air supplying device includes an evaporator generating a cool air, a blower fan guiding the cool air generated by the evaporator so that the cool air is supplied to the storage compartment, and a cool air duct receiving the cool air guided by the blower fan and discharging the guided cool air to the storage compartment. 
     In the cool air duct, a plurality of discharging ports may be provided to discharge the received cool air to the storage compartment, but an ice or frost may be generated in the cool air discharging port due to the long use of the refrigerator. 
     A defrost heater may be operated to remove the ice or frost generated in the cool air discharging port. Air heated by the defrost heater removes the ice or frost generated in the cool air discharging port and then discharged to the storage compartment via the cool air discharging port. 
     Since the air that is heated by the defrost heater is discharged to the cool air discharging port while having a high temperature after removing the ice or frost generated in the cool air discharging port, there may cause a problem of increasing a temperature of the storage compartment. 
     SUMMARY 
     Therefore, it is an aspect of the present disclosure to provide a refrigerator capable of delaying an increase of a temperature of a storage compartment by allowing a temperature of air that is heated by a defrost heater to be lowered and then discharged to the storage compartment. 
     Additional aspects of the present disclosure will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. 
     In accordance with one aspect of the present disclosure, a refrigerator includes a body, a storage compartment provided inside of the body to have an opened front surface, an evaporator provided in a rear side of the storage compartment to generate cool air, a defrost heater provided in a lower side of the evaporator, a lower cool air duct having a first flow path configured to guide cool air generated by the evaporator to be supplied to the storage compartment, and an upper cool air duct disposed in an upper side of the lower cool air duct where the upper cool air duct includes a second flow path configured to guide cool air generated by the evaporator to be supplied to the storage compartment. A cool pack in which storage material is filled stores cold storage energy from cool air passing through the second flow path of the upper cool air duct to decrease a temperature of air passing via the second flow path of ht upper cool air duct while the defrost heater is being operated, so that an increase of an internal temperature of the storage compartment is delayed. 
     The evaporator and a blower fan may configured to guide cool air generated by the evaporator to be delivered to the first flow path and the second flow path are mounted to the lower cool air duct, wherein the blower fan is mounted to an upper side of the evaporator. 
     The lower cool air duct may comprise a flow path unit to which the evaporator and the blower fan are mounted, and in which the first flow path is provided, and a first front cover provided in a front surface of the flow path unit to form a part of a rear wall of the storage compartment and provided with a plurality of first cool air discharging ports configured to discharge cool air that is delivered to the first flow path to the storage compartment. 
     The upper cool air duct may comprise a second front cover provided in a front surface of the cool pack to form a part of a rear wall of the storage compartment and provided with a plurality of second cool air discharging ports configured to discharge cool air that is delivered to the second flow path to the storage compartment. 
     The second flow path may be provided in a rear surface of the cool pack, wherein a rear cover configured to cover a rear side of the cool pack is provided in a rear side of the cool pack. 
     The cool pack may comprise an inlet configured to fill cold storage material and a third cool air discharging port provided in a position corresponding to the second cool air discharging port to discharge the cool air that is delivered to the second flow path to the storage compartment. 
     A plurality of protrusions protruded toward a rear side may be provided in a rear surface of the cool pack forming the second flow path. 
     An upper cool pack in which cold storage material may be filled is mounted to an upper portion of an inside of the storage compartment, wherein the upper cool pack stores cold storage energy from cool air discharged via the plurality of the second cool air discharging ports. 
     A coupling hole may be provided in the upper cool pack to allow the upper cool pack to be coupled to an upper portion of the inside of the storage compartment by a coupling member. 
     A plurality of fixation protrusions may be provided in the upper portion of the inside of the storage compartment, wherein a plurality of fixation unit is provided in the upper cool pack to be fixed by being coupled to the plurality of fixation protrusions. 
     The upper cool pack performs heat exchange with air, which is heated by the defrost heater when defrosting and then discharged via the plurality of the second cool air discharging ports by being passed through the second flow path, so that an increase of an internal temperature of the storage compartment may be delayed. 
     In accordance with another aspect of the present disclosure, a refrigerator includes a body, a storage compartment provided inside of the body to have an opened front surface, an evaporator provided in a rear side of the storage compartment to generate cool air, a defrost heater provided in a lower side of the evaporator, a lower cool air duct having a first flow path configured to guide cool air generated by the evaporator to be supplied to the storage compartment, an upper cool air duct disposed in an upper side of the lower cool air duct and provided with a second flow path configured to guide cool air generated by the evaporator to be supplied to the storage compartment. The refrigerator including a cool pack, in which cold storage material is filled, provided to an upper portion of an inside of the storage compartment, wherein the cool pack stores cold storage energy from cool air discharged from the upper cool air duct to decrease a temperature of air discharged from the upper cool air duct to the storage compartment while the defrost heater is being operated, so that increase in an internal temperature of the storage compartment due to heat from the defrost heater is delayed. 
     A coupling hole may be provided in the cool pack to allow the cool pack to be coupled to the upper portion of the inside of the storage compartment by a coupling member. 
     A plurality of fixation protrusions may be provided in the upper portion of the inside of the storage compartment, wherein a plurality of fixation unit is provided in the cool pack to be fixed by being coupled to the plurality of fixation protrusions. 
     In accordance with another aspect of the present disclosure, a refrigerator includes a body, a storage compartment provided inside of the body to have an opened front surface, an evaporator provided in a rear side of the storage compartment to generate cool air, a defrost heater provided in a lower side of the evaporator, a cool air duct provided with the evaporator mounted thereto and a flow path configured to guide cool air generated by the evaporator to be supplied to the storage compartment. The refrigerator includes a cool pack, in which cold storage material is filled, provided to an upper portion of an inside of the storage compartment, wherein the cool pack stores cold storage energy from cool air discharged from the cool air duct to decrease a temperature of air discharged from the cool air duct to the storage compartment while the defrost heater is operated, so that increase of an internal temperature of the storage compartment due to heat from the defrost heater is delayed. 
     The evaporator and a blower fan may configure to guide cool air generated by the evaporator to be delivered to the flow path are mounted to the lower cool air duct, wherein the blower fan is mounted to an upper side of the evaporator. 
     The cool air duct may comprise a flow path unit to which the evaporator and the blower fan are mounted, and in which the flow path is provided, and a front cover provided in a front surface of the flow path unit to form a rear wall of the storage compartment and provided with a plurality of cool air discharging ports configured to discharge cool air that is delivered to the flow path to the storage compartment. 
     A coupling hole may be provided in the cool pack to allow the cool pack to be coupled to the upper portion of the inside of the storage compartment by a coupling member. 
     A plurality of fixation protrusions may be provided in the upper portion of the inside of the storage compartment, wherein a plurality of fixation unit is provided in the cool pack to be fixed by being coupled to the plurality of fixation protrusions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and/or other aspects of the disclosure will become apparent and more readily appreciated from the following description of embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  is a perspective view illustrating a refrigerator in accordance with one embodiment of the present disclosure; 
         FIG. 2  is a cross-sectional view illustrating a refrigerator in accordance with one embodiment of the present disclosure; 
         FIG. 3  is a perspective view illustrating a front surface of a cool air duct in accordance with one embodiment of the present disclosure; 
         FIG. 4  is a perspective view illustrating a rear surface of a cool air duct in accordance with one embodiment of the present disclosure; 
         FIG. 5  is a an exploded-perspective view illustrating a cool air duct in accordance with one embodiment of the present disclosure; 
         FIG. 6  is a view illustrating a first flow path and a second flow path of a cool air duct in accordance with one embodiment of the present disclosure; 
         FIG. 7  is a view illustrating that cool air generated by an evaporator of a refrigerator is supplied to a storage compartment in accordance with one embodiment of the present disclosure; 
         FIG. 8  is a view illustrating that air heated by a defrost heater of a refrigerator is discharged to a storage compartment in accordance with one embodiment of the present disclosure; 
         FIG. 9  is a view illustrating that cool air generated by an evaporator of a refrigerator is supplied to a storage compartment in accordance with another embodiment of the present disclosure; 
         FIG. 10  is a view illustrating that air heated by a defrost heater of a refrigerator is discharged to a storage compartment in accordance with another embodiment of the present disclosure; 
         FIG. 11  is a view illustrating an upper cool pack of  FIG. 9 ; 
         FIG. 12  is a partial enlarged view illustrating that an upper cool pack of  FIG. 9  is mounted to an upper portion of the inside of a storage compartment; 
         FIG. 13  is a cross-sectional view illustrating a refrigerator in accordance with another embodiment of the present disclosure; 
         FIG. 14  is a view illustrating an upper cool pack of  FIG. 13 ; 
         FIG. 15  is a partial enlarged view illustrating that an upper cool pack of  FIG. 13  is mounted to an upper portion of the inside of a storage compartment; 
         FIG. 16  is a view illustrating that cool air generated by an evaporator of a refrigerator is supplied to a storage compartment in accordance with another embodiment of the present disclosure; 
         FIG. 17  is a view illustrating that air heated by a defrost heater of a refrigerator is discharged to a storage compartment in accordance with another embodiment of the present disclosure; 
         FIG. 18  is a view illustrating a cool pack of  FIG. 16 ; 
         FIG. 19  is a partial enlarged view illustrating that a cool pack of  FIG. 16  is mounted to an upper portion of the inside of a storage compartment; 
         FIG. 20  is a cross-sectional view illustrating a refrigerator in accordance with another embodiment of the present disclosure; 
         FIG. 21  is a view illustrating a cool pack of  FIG. 20 ; 
         FIG. 22  is a partial enlarged view illustrating that a cool pack of  FIG. 20  is mounted to an upper portion of the inside of a storage compartment; 
         FIG. 23  is a cross-sectional view illustrating a refrigerator in accordance with another embodiment of the present disclosure; 
         FIG. 24  is a view illustrating a cool air duct in accordance with another embodiment of the present disclosure; 
         FIG. 25  is a an exploded-perspective view illustrating a cool air duct in accordance with another embodiment of the present disclosure; 
         FIG. 26  is a view illustrating that cool air generated by an evaporator of a refrigerator is supplied to a storage compartment in accordance with another embodiment of the present disclosure; 
         FIG. 27  is a view illustrating that air heated by a defrost heater of a refrigerator is discharged to a storage compartment in accordance with another embodiment of the present disclosure; 
         FIG. 28  is a view illustrating a cool pack of  FIG. 26 ; 
         FIG. 29  is a partial enlarged view illustrating that a cool pack of  FIG. 26  is mounted to an upper portion of the inside of a freezing compartment; 
         FIG. 30  is a perspective view illustrating a refrigerator in accordance with another embodiment of the present disclosure; 
         FIG. 31  is a perspective view illustrating a cool air duct in accordance with another embodiment of the present disclosure; 
         FIG. 32  is an exploded-perspective view illustrating a cool air duct in accordance with another embodiment of the present disclosure; 
         FIG. 33  is a view illustrating that cool air generated by a first evaporator of a refrigerator, in which a cool pack is mounted to an upper surface of the inside of a lower storage compartment, is supplied to the lower storage compartment in accordance with another embodiment of the present disclosure; 
         FIG. 34  is a view illustrating that air heated by a defrost heater of a refrigerator, in which a cool pack is mounted to an upper surface of the inside of a lower storage compartment, is discharged to the lower storage compartment in accordance with another embodiment of the present disclosure; 
         FIG. 35  is a view illustrating that cool air generated by a first evaporator of a refrigerator, in which a cool pack and an auxiliary flow path are provided, is supplied to a lower storage compartment in accordance with another embodiment of the present disclosure; 
         FIG. 36  is a view illustrating that air heated by a defrost heater of a refrigerator, in which a cool pack and an auxiliary flow path are provided, is discharged to a lower storage compartment in accordance with another embodiment of the present disclosure; 
         FIG. 37  is a view illustrating that cool air generated by a first evaporator of a refrigerator, to which an inner case cool pack is mounted, is supplied to a lower storage compartment in accordance with another embodiment of the present disclosure; 
         FIG. 38  is a view illustrating that air heated by a defrost heater of a refrigerator, to which an inner case cool pack is mounted, is discharged to a lower storage compartment in accordance with another embodiment of the present disclosure; 
         FIG. 39  is a view illustrating that cool air generated by a first evaporator of a refrigerator, in which a cool pack and an inner case cool pack are provided, is supplied to a lower storage compartment in accordance with another embodiment of the present disclosure; and 
         FIG. 40  is a view illustrating that air heated by a defrost heater of a refrigerator, in which a cool pack and an inner case cool pack are provided, is discharged to a lower storage compartment in accordance with another embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. 
     As illustrated in  FIGS. 1 and 2 , a refrigerator may include a body  10  forming an exterior of the refrigerator; a storage compartment  20  provided inside of the body  10  to have an opened front surface thereof; and a door  30  rotatably coupled to the body  10  to open and close the opened front surface of the storage compartment  20 . 
     The body  10  may include an inner case  11  forming the storage compartment  20  and an outer case  13  forming an exterior of the body  10 , and an insulation material  15  may be foamed between the inner case  11  and the outer case  13  to prevent cool air of the storage compartment  20  from being leaked. 
     The body  10  may include a partition  17  dividing the storage compartment  20  into a refrigerating compartment  21  in the left side and a freezing compartment  23  in the right side. A machinery room  29  in which a compressor  41  configured to compress refrigerant and a condenser (not shown) configured to condense the compressed refrigerant are installed may be provided in a lower portion of the rear side of the body  10 . 
     The storage compartment  20  may be divided into the left side and the right side by the partition  17 , wherein the refrigerating compartment  21  may be provided in the right side of the body  10  and the freezing compartment  23  may be provided in the left side of the body  10 . 
     In the inside of the storage compartment  20 , a plurality of shelves  25  and storage containers  27  may be provided to store foods. 
     The storage compartment  20  may be opened or closed by the door  30  rotatably coupled to the body  10 , and the refrigerating compartment  21  and the freezing compartment  23  which are divided into the left side and the right side by the partition  17  may be opened or closed by a refrigerating compartment door  31  and a freezing compartment door  33 , respectively. 
     On the rear surface of the refrigerating compartment door  31  and the freezing compartment door  33 , a plurality of door guards  35  may be provided to accommodate foods. 
     The cool air supplying device may include the compressor  41  and the condenser both of which are installed in the machinery room  29 , an evaporator  43  installed in the rear surface of the storage compartment  20  to generate a cool air, a blower fan  45  provided in an upper side of the evaporator  43  to guide the cool air generated in the evaporator  43  to the storage compartment  20 , and a cool air duct  100  configured to guide the cool air guided by the blower fan  45  to be discharged to the storage compartment  20 . 
     A defrost heater  50  may be provided in a lower side of the evaporator  43 . When an ice or frost is generated in the discharging port provided in the cool air duct  100  and thus cool air generated in the evaporator  43  is prevented from being discharged to the storage compartment  20 , the defrost heater  50  may be operated to allow cool air to be smoothly discharged to the storage compartment  20  by removing an ice or frost generated in the discharging port. 
     As illustrated in  FIGS. 2 to 6 , the cool air duct  100  may be provided in a rear side of the storage compartment  20  to guide cool air generated by the evaporator  43  so that the cool air is supplied to the storage compartment  20 . 
     The cool air duct  100  may include a lower cool air duct  110  provided in a lower portion of the rear side of the storage compartment  20  and an upper cool air duct  120  disposed on an upper side of the lower cool air duct  110  to be provided in an upper portion of the rear side of the storage compartment  20 . 
     The evaporator  43  and the blower fan  45  may be mounted to the lower cool air duct  110 , and alternatively, the blower fan  45  may be mounted to an upper side of the evaporator  43 . 
     The lower cool air duct  110  may include a flow path unit  111  to which the evaporator  43  and the blower fan  45  are mounted, and in which a first flow path  113  configured to guide cool air generated by the evaporator  43  to be supplied to the storage compartment  20  is provided; a first front cover  115  provided in a front surface of the flow path unit  111  to form a part of a rear wall of the storage compartment  20 ; and a rear surface cover  119  provided in a rear surface of the flow path unit  111 . 
     In the first front cover  115 , a plurality of first cool air discharging ports  117  configured to discharge cool air, which is delivered to the first flow path  113 , to the storage compartment  20  may be provided, and since the lower cool air duct  110  is placed in a lower portion of the rear side of the storage compartment  20 , the cool air discharged from the plurality of first cool air discharging ports  117  may be supplied to a lower portion of the storage compartment  20 . 
     The upper cool air duct  120  may be provided in an upper side of the lower cool air duct  110 , and the upper cool air duct  120  may include a cool pack  121  in which a second flow path  123  configured to guide cool air generated by the evaporator  43  to be supplied to the storage compartment  20  is provided, a second front cover  126  provided in a front surface of the cool pack  121  to form a part of a rear wall of the storage compartment  20 , and a rear cover  128  configured to cover a rear side of the cool pack  121 . 
     In the second front cover  126 , a plurality of second cool air discharging ports  127  configured to discharge cool air, which is delivered to the second flow path  123 , to the storage compartment  20  may be provided, and since the upper cool air duct  120  is placed in an upper portion of the rear side of the storage compartment  20 , the cool air discharged from the plurality of second cool air discharging ports  127  may be supplied to an upper portion of the storage compartment  20 . 
     The cool pack  121  may be filled with cold storage material. The cool pack  121  may include an inlet  122  into which the cold storage material is put and a third cool air discharging port  124  provided in a position corresponding to the second cool air discharging port  127  to discharge the cool air that is delivered to the second flow path  123  to the storage compartment  20 . 
     The inlet  122  into which the cold storage material is put may be provided to be opened and closed by a cap  122   a , and after the inlet  122  is opened by pulling the cap  122   a  from the inlet  122 , the cold storage material may be put into the inside of the cool pack  121  and then the inlet  122  may be closed by the cap  122   a  when putting the cold storage material is completed. 
     Since the cold storage material is filled in the inside of the cool pack  121 , the cool pack  121  may store cold storage energy from cool air that is passed through the second flow path  123  in a process in which cool air generated by the evaporator  43  is discharged to the storage compartment  20  via the second flow path  123 . 
     A plurality of protrusions  125  protruding toward a rear side may be provided in a rear surface of the cool pack  121  forming the second flow path  123 . 
     The plurality of protrusions  125  may be provided on the second flow path  123  to allow heat exchange with the cool pack  121  to be effectively performed when cool air generated by the evaporator  43  or air heated by the defrost heater  50  is passed through the second flow path  123 . 
     As illustrated in  FIG. 7 , when the refrigerator is operated, cool air generated by the evaporator  43  may be typically guided to the first flow path  113  of the lower cool air duct  110  and the second flow path  123  of the upper cool air duct  120  by the blower fan  45 . 
     Cool air guided to the first flow path  113  may be discharged to a lower side of the storage compartment  20  via the first cool air discharging port  117  of the first front cover  115  and cool air guided to the second flow path  123  may be discharged to an upper side of the storage compartment  20  via the second cool air discharging port  127  of the second front cover  126 . 
     The cool pack  121  may store cold storage energy from cool air that is passed through the second flow path  123  in a process in which cool air is discharged to the storage compartment  20 . 
     As illustrated in  FIG. 8 , when cool air is not smoothly discharged to the storage compartment  20  since an ice or frost is generated in the second cool air discharging port  127  of the second front cover  126 , the defrost heater  50  may be operated. 
     When the defrost heater  50  is operated, air heated by the defrost heater  50  may be raised due to natural convection and then guided to the second flow path  123  of the upper cool air duct  120 . 
     Since air guided to the second flow path  123  is maintained in a high temperature, an ice or frost generated in the second cool air discharging port  127  of the second front cover  126  may be removed by the air having a high temperature so that cool air is smoothly supplied to the storage compartment  20 . 
     Air heated by the defrost heater  50  may be discharged to the storage compartment  20  via the second cool air discharging port  127  after removing the ice or frost generated in the second cool air discharging port  127  of the second front cover  126 . 
     In a process in which air heated by the defrost heater  50  passes through the second flow path  123 , a temperature of the air may be lowered by performing heat exchange with the cool pack  121  in which cold storage energy is stored, and air in a lowered temperature may be discharged to the storage compartment  20  via the second cool air discharging port  127  so that the air having a high temperature that is heated by the defrost heater  50  is prevented from being directly discharged to the storage compartment  20 . 
     Since the air heated by the defrost heater  50  is not directly discharged to the storage compartment  20  while having a high temperature, but the air is discharged to the storage compartment  20  after decreasing a temperature thereof due to the heat exchange, a temperature of the storage compartment  20  may be prevented from being increased. 
     Since the plurality of protrusions  125  is provided on the rear surface of the cool pack  121  forming the second flow path  123 , a period of time when the air heated by the defrost heater  50  is placed in the second flow path  123  may be increased. Accordingly, the air heated by the defrost heater  50  may perform the heat exchange for a long time to have a lower temperature than a temperature of air in a state in which the plurality of the protrusion  125  do not exist, and then the air may be discharged to the storage compartment  20 . 
     As illustrated in  FIG. 9 , an upper cool pack  130  in which cold storage material is filled may be mounted to an upper portion of the inside of the storage compartment  20 . 
     In a process in which cool air generated by the evaporator  43  is discharged to the storage compartment  20  via the second flow path  123 , the upper cool pack  130  may store cold storage energy from cool air that is passed through the second flow path  123  and then discharged via the plurality of the second cool air discharging port  127 . 
     Particularly, the upper cool pack  130  may store cold storage energy from cool air that is discharged from the second cool air discharging port  127  that is placed in the most upper side among the plurality of the second cool air discharging port  127 . 
     As illustrated in  FIG. 10 , when the defrost heater  50  is operated to remove the ice or frost generated in the second cool air discharging port  127  of the second front cover  126 , air heated by the defrost heater  50  may be raised due to natural convection and then guided to the second flow path  123  of the upper cool air duct  120 . 
     Since air guided to the second flow path  123  is maintained in a high temperature, an ice or frost generated in the second cool air discharging port  127  of the second front cover  126  may be removed by the air having a high temperature so that cool air is smoothly supplied to the storage compartment  20 . 
     Air heated by the defrost heater  50  may be discharged to the storage compartment  20  via the second cool air discharging port  127  after removing the ice or frost generated in the second cool air discharging port  127  of the second front cover  126 . 
     In a process in which air heated by the defrost heater  50  passes through the second flow path  123 , a temperature of the air may be lowered by performing heat exchange with the cool pack  121  in which the cold storage energy is stored, and air in a lowered temperature may be discharged to the storage compartment  20  via the second cool air discharging port  127  so that the air having a high temperature that is heated by the defrost heater  50  is prevented from being directly discharged to the storage compartment  20 . 
     Although the air heated by the defrost heater  50  is discharged to the storage compartment  20  while being in a lowered temperature due to the heat exchange with the cool pack  121 , a temperature of air discharged to the second cool air discharging port  127  may be higher than a temperature of air inside of the storage compartment  20  and thus a temperature of the storage compartment  20  may be increased by a certain level. 
     However, since the upper cool pack  130  in which the cold storage energy is stored may be additionally provided in the upper portion of the inside of the storage compartment  20 , a temperature of air, which is discharged from the second cool air discharging port  127  that is placed in the most upper side among the plurality of the second cool air discharging port  127 , may be lowered due to the heat exchange with the upper cool pack  130 . 
     In addition, a temperature of air, which is discharged from the remaining second cool air discharging port  127  except for the second cool air discharging port  127  that is placed in the most upper side among the plurality of the second cool air discharging port  127 , may be lowered by the upper cool pack  130  disposed inside of the storage compartment  20  so that a temperature of entire inside of the storage compartment  20  may be maintained in a low temperature. 
     As illustrated in  FIGS. 11 and 12 , the upper cool pack  130  may include an inlet  131  into which cold storage material is put, and a coupling hole  135  configured to mount the upper cool pack  130  to the upper portion of the inside of the storage compartment  20 . 
     The inlet  131  may be provided to be opened and closed by a cap  133 , and after the inlet  131  is opened by pulling the cap  133  from the inlet  131 , the cold storage material may be put into the inside of the upper cool pack  130  and then the inlet  131  may be closed by the cap  133  when putting the cold storage material is completed. 
     When the cold storage material is put into the inside of the upper cool pack  130  and then the inlet  131  is closed by the cap  133 , the upper cool pack  130  may be mounted to an upper surface of the inside of the storage compartment  20  through a coupling member (B) that is inserted into the coupling hole  135 . 
     As illustrated in  FIGS. 13 to 15 , an upper cool pack  140  may be fixed by being coupled to a plurality of fixation protrusions  147  provided in an upper portion of the inside of the storage compartment  20 . 
     The upper cool pack  140 , which is fixed by being coupled to the plurality of fixation protrusions  147  provided in the upper portion of the inside of the storage compartment  20 , may include an inlet  141  into which the cold storage material is put, and a plurality of fixation units  145  fixed such that the plurality of the fixation protrusions  147  is inserted thereto. 
     The inlet  141  may be provided to be opened and closed by a cap  143 , and after the inlet  141  is opened by pulling the cap  143  from the inlet  141 , the cold storage material may be put into the inside of the upper cool pack  140  and then the inlet  141  may be closed by the cap  143  when putting the cold storage material is completed. 
     When the cold storage material is put into the inside of the upper cool pack  140  and then the inlet  141  is closed by the cap  143 , the upper cool pack  140  may be mounted to an upper surface of the inside of the storage compartment  20  such that the plurality of the fixation units  145  is coupled to the plurality of the fixation protrusions  147  provided on the upper portion of the inside of the storage compartment  20 . 
     As illustrated in  FIG. 16 , in a lower portion of the rear side of the storage compartment  20 , an evaporator  43  may be mounted and a first flow path  211  configured to guide cool air generated by the evaporator  43  to be supplied to the storage compartment  20  may be provided. In an upper portion of the rear side of the storage compartment  20 , an upper cool air duct  220  may be provided in an upper side of the lower cool air duct  210  and provided with a second flow path  221  configured to guide cool air generated by the evaporator  43  to be supplied to the storage compartment  20 . 
     The configuration of the lower cool air duct  210  is to discharge cool air generated by the evaporator  43  to the first cool air discharging port  213 , and is the same as the configuration of the lower cool air duct  110  illustrated in  FIG. 7 . Therefore, a description of the same parts as those shown in  FIG. 7  will be omitted. 
     The upper cool air duct  220  may be configured to have the second flow path  221  to which cool air generated by the evaporator  43  is guided by the blower fan  45  and a plurality of second cool air discharging ports  223  provided in a front surface to discharge cool air, which is guided to the second flow path  221 , to the storage compartment  20 . 
     A cool pack  230  configured to store cold storage energy from cool air generated by the evaporator  43  may be not provided in the upper cool air duct  220  but in an upper portion of the inside of the storage compartment  20 . 
     In a process in which cool air generated by the evaporator  43  is discharged to the storage compartment  20  via the second flow path  221 , the cool pack  230  may store the cold storage energy from cool air that is passed through the second flow path  221  and discharged via the plurality of the second cool air discharging port  223 . 
     Particularly, the cool pack  230  may store the cold storage energy from cool air that is discharged from the second cool air discharging port  223  that is placed in the most upper side among the plurality of the second cool air discharging port  223 . 
     As illustrated in  FIG. 17 , when the defrost heater  50  is operated to remove the ice or frost generated in the second cool air discharging port  223 , air heated by the defrost heater  50  may be raised due to natural convection and then guided to the second flow path  221  of the upper cool air duct  220 . 
     Since air guided to the second flow path  221  is maintained in a high temperature, the ice or frost generated in the second cool air discharging port  223  may be removed by the air having a high temperature so that cool air is smoothly supplied to the storage compartment  20 . 
     Air heated by the defrost heater  50  may be discharged to the storage compartment  20  via the second cool air discharging port  223  after removing the ice or frost generated in the second cool air discharging port  223 . 
     Since air heated by the defrost heater  50  is discharged to the storage compartment  20  via the plurality of the second cool air discharging port  223 , and the cool pack  230  configured store the cold storage energy is disposed on the upper portion of the inside of the storage compartment  20 , a temperature of air, which is discharged via the second cool air discharging port  223  that is placed in the most upper side among the plurality of the second cool air discharging port  223 , may be lowered due to the heat exchange with the cool pack  230 . 
     A temperature of air, which is discharged from the remaining second cool air discharging port  223  except for the second cool air discharging port  223  that is placed in the most upper side among the plurality of the second cool air discharging port  223 , may be lowered by the cool pack  230  disposed inside of the storage compartment  20  so that a temperature of entire inside of the storage compartment  20  may be maintained in a low temperature. 
     As illustrated in  FIGS. 18 and 19 , the cool pack  230  may include an inlet  231  into which cold storage material is put, and a coupling hole  235  configured to mount the cool pack  230  to the upper portion of the inside of the storage compartment  20 . 
     The inlet  231  may be provided to be opened and closed by a cap  233 , and after the inlet  231  is opened by pulling the cap  233  from the inlet  231 , the cold storage material may be put into the inside of the cool pack  230  and then the inlet  231  may be closed by the cap  233  when putting the cold storage material is completed. 
     When the cold storage material is put into the inside of the cool pack  230  and then the inlet  231  is closed by the cap  233 , the cool pack  230  may be mounted to an upper surface of the inside of the storage compartment  20  through a coupling member (B) that is inserted into the coupling hole  235 . 
     As illustrated in  FIGS. 20 to 22 , an upper cool pack  240  may be fixed by being coupled to a plurality of fixation protrusions  247  provided in an upper portion of the inside of the storage compartment  20 . 
     The cool pack  240 , which is fixed by being coupled to the plurality of fixation protrusions  247  provided in the upper portion of the inside of the storage compartment  20 , may include an inlet  241  into which the cold storage material is put, and a plurality of fixation units  245  fixed such that the plurality of the fixation protrusions  247  is inserted thereto. 
     The inlet  241  may be provided to be opened and closed by a cap  243 , and after the inlet  241  is opened by pulling the cap  243  from the inlet  241 , the cold storage material may be put into the inside of the cool pack  240  and then the inlet  241  may be closed by the cap  243  when putting the cold storage material is completed. 
     When the cold storage material is put into the inside of the cool pack  240  and then the inlet  241  is closed by the cap  243 , the cool pack  240  may be mounted to an upper portion of the inside of the storage compartment  20  such that the plurality of the fixation units  245  is coupled to the plurality of the fixation protrusions  247  provided on the upper portion of the inside of the storage compartment  20 . 
     As illustrated in  FIG. 23 , a refrigerator may include a body  60 ; a storage compartment  70  provided inside of the body  60  to have an opened front surface thereof; and a door  80  rotatably coupled to the body  60  to open and close the opened front surface of the storage compartment  70 . 
     The body  60  may include an inner case  61  forming the storage compartment  70  and an outer case  63  forming an exterior, and an insulation material  65  may be foamed between the inner case  61  and the outer case  63  to prevent cool air of the storage compartment  70  from being leaked. 
     The storage compartment  70  may be divided into a freezing compartment  71  that is an upper storage compartment and a refrigerating compartment  73  that is a lower storage compartment, by a partition  67 . In the inside of the storage compartment  70 , a plurality of shelves  75  configured to store foods thereon may be provided to divide the freezing compartment  71  and the refrigerating compartment  73  into multi-spaces, respectively. 
     In the inside of the storage compartment  70 , a storage container  77  may be provided to store foods. 
     A machinery room  79  in which a compressor  91  configured to compress refrigerant and a condenser (not shown) configured to condense the compressed refrigerant are installed may be provided in a lower portion of the rear side of the body  60 . 
     The freezing compartment  71  and the refrigerating compartment  73  may be opened or closed by a freezing compartment door  81  and a refrigerating compartment door  83  rotatably coupled to the body  60 , respectively, and on the rear surface of the freezing compartment door  81  and the refrigerating compartment door  83 , a plurality of door guards  85  may be provided to accommodate foods. 
     A cool air supplying device (not shown) configured to supply cool air to the inside of the storage compartment  20  may be provided inside of the body  60 . 
     The cool air supplying device may include the compressor  91 , the condenser, an expansion valve (not shown), an evaporator  93 , a blower fan  95 , and a cool air duct  300 . 
     The compressor  91  and the condenser may be provided inside of the machinery room  79 , as mentioned above, and the evaporator  93  and the blower fan  95  may be provided in the rear side of the freezing compartment  71 . 
     The evaporator  93  may generate cool air by the heat exchange of the refrigerant, and cool air generated by the evaporator  93  may be guided to the cool air duct  300  by the blower fan  95  provided in an upper side of the evaporator  93  and then the cool air may be supplied to the freezing compartment  71 . 
     As illustrated in  FIGS. 23 to 25 , the cool air duct  300  may include a flow path unit  310  to which the evaporator  93  and the blower fan  95  are mounted, and in which a flow path  311  is provided; and a front cover  320  provided in a front surface of the flow path unit  310  to form a rear wall of the freezing compartment  71  and in which a plurality of cool air discharging ports  321  configured to discharge cool air, which is delivered to the flow path  311 , to the freezing compartment  71  is provided. 
     Cool air generated by the evaporator  93  may be guided to the flow path  311  by the blower fan  95 , a portion of cool air guided to the flow path  311  may be supplied to the freezing compartment  71  via the front cover  320 , and the rest of the cool air may be supplied to the refrigerating compartment  73  via a cool air duct provided in the rear side of the refrigerating compartment  73 . 
     A cool pack  330  configured to store the cold storage energy from cool air generated by the evaporator  93  may be provided in an upper portion of the inside of the freezing compartment  71 . 
     As illustrated in  FIG. 26 , in a process in which cool air generated by the evaporator  93  is discharged to the freezing compartment  71  via the flow path  311 , the cool pack  330  may store the cold storage energy from cool air that is passed through the flow path  311  and discharged via the plurality of the cool air discharging ports  321 . 
     Particularly, the cool pack  330  may store the cold storage energy from cool air that is discharged from the cool air discharging port  321  that is placed in the most upper side among the plurality of the cool air discharging ports  321 . 
     As illustrated in  FIG. 27 , when the defrost heater  50  is operated to remove the ice or frost generated in the cool air discharging port  321 , air heated by the defrost heater  50  may be raised due to natural convection and then guided to an upper side of the flow path  311  of the cool air duct  300 . 
     Since air guided to the upper side of the flow path  311  is maintained in a high temperature, an ice or frost generated in the cool air discharging port  321  may be removed by the air having a high temperature so that cool air is smoothly supplied to the freezing compartment  71 . 
     Air heated by the defrost heater  50  may be discharged to the freezing compartment  71  via the cool air discharging port  321  after removing the ice or frost generated in the cool air discharging port  321 . 
     Since air heated by the defrost heater  50  is discharged to the freezing compartment  71  via the cool air discharging port  321  that is placed in the most upper side among the plurality of the cool air discharging ports  321  and the cool pack  330  configured store the cold storage energy is disposed on the upper portion of the inside of the freezing compartment  71 , a temperature of air, which is discharged via the cool air discharging port  321  that is placed in the most upper side among the plurality of the cool air discharging ports  321 , may be lowered due to the heat exchange with the cool pack  330 . 
     As illustrated in  FIGS. 26 to 29 , the cool pack  330  may be fixed by being coupled to a plurality of fixation protrusions  337  provided in an upper portion of the inside of the freezing compartment  71 . 
     The cool pack  330 , which is fixed by being coupled to the plurality of fixation protrusions  337  provided in the upper portion of the inside of the freezing compartment  71 , may include an inlet  331  into which the cold storage material is put, and a plurality of fixation units  335  fixed such that the plurality of the fixation protrusions  337  is inserted thereto. 
     The inlet  331  may be provided to be opened and closed by a cap  333 , and after the inlet  331  is opened by pulling the cap  333  from the inlet  331 , the cold storage material may be put into the inside of the cool pack  330  and then the inlet  331  may be closed by the cap  333  when putting the cold storage material is completed. 
     When the cold storage material is put into the inside of the cool pack  330  and then the inlet  331  is closed by the cap  333 , the cool pack  330  may be mounted to an upper portion of the inside of the freezing compartment  71  such that the plurality of the fixation units  335  is coupled to the plurality of the fixation protrusions  337  provided on the upper portion of the inside of the freezing compartment  71 . 
     Although not shown in the drawings, the cool pack  330  may be mounted to an upper surface of the inside of the freezing compartment  71  by a coupling member (B) as the same method as the cool pack  230  as illustrated in  FIGS. 16 to 19 . 
     As illustrated in  FIGS. 30 to 33 , a refrigerator may include a body  400 ; a storage compartment  410  provided inside of the body  400  to have an opened front surface thereof; and a door  420  rotatably coupled to the body  400  to open and close the opened front surface of the storage compartment  410 . 
     The body  400  may include an inner case  401  forming the storage compartment  410  and an outer case  403  forming an exterior, and an insulation material  405  may be foamed between the inner case  401  and the outer case  403  to prevent a cool air of the storage compartment  410  from being leaked. 
     The storage compartment  410  may be divided into a plurality of the storage compartments  410  by a partition  407 . In the inside of the storage compartment  410 , a plurality of shelves  417  and a storage container  418  may be provided to store foods. The opened front surface of the storage compartment  410  may be opened and closed by the door  420 . 
     The storage compartment  410  may be divided into a plurality of storage compartments  411 ,  414  and  415  by the partition  407 , and the partition  407  may include a first partition  408  configured to divide the storage compartment  410  into an upper storage compartment  411  and a lower storage compartment  413  by being horizontally coupled to the inside of the storage compartment  410  and a second partition  409  configured to divide the lower storage compartment  413  into a first storage compartment  414  and a second storage compartment  415  by being vertically coupled to the inside of the lower storage compartment  413 . 
     The partition  407  having a T shape by coupling the first partition  408  to the second partition  409  may divide the storage compartment  410  into three spaces. 
     The upper storage compartment  411  between the upper storage compartment  411  and the lower storage compartment  413  which are divided by the first partition  408  may be used as a refrigerating compartment and the lower storage compartment  413  may be used as a freezing compartment. 
     An entire space of the lower storage compartment  413  may be used as a freezing compartment, the first storage compartment  414  may be used as a freezing compartment and the second storage compartment  415  may be used as a refrigerating compartment. Alternatively, the first storage compartment  414  may be used as a freezing compartment and the second storage compartment  415  may be used as both of a freezing compartment and a refrigerating compartment. 
     The division of the storage compartment  410  is an example, and each of the storage compartments  411 ,  414  and  415  may be used in a different manner from the above mentioned configuration. 
     The door  420  may include an upper door  421  configured to open and close the upper storage compartment  411  and a lower door  423  configured to open and close the lower storage compartment  413 , and on the rear surface of the door  420 , a plurality of door guards  425  may be provided to accommodate foods. 
     A cool air supplying device (not shown) configured to supply cool air to the inside of the storage compartment  410  may be provided inside of the body  400 . 
     The cool air supplying device may include a compressor  431 , a condenser (not shown), an expansion valve (not shown), an evaporator  433  and  435 , a blower fan  437  and  439 , and a cool air duct  500 . 
     The compressor  431  and the condenser may be provided inside of a machinery room  419  and the evaporator  433  and  435  and the blower fan  437  and  439  may be provided in the rear side of the storage compartment  410 . 
     The evaporator  433  and  435  may generate cool air by the heat exchange of the refrigerant, and cool air generated by the evaporator  433  and  435  may be guided to the cool air duct  500  by the blower fan  437  and  439  provided in an upper side of the evaporator  433  and  435  and then the cool air may be supplied to the storage compartment  410 . 
     The cool air duct  500  may include a first cool air duct  510  provided in a rear side of the lower storage compartment  413  and a second cool air duct  520  provided in a rear side of the upper storage compartment  411 . 
     A second evaporator  435  and a second blower fan  439  may be mounted to the second cool air duct  520 , and the second cool air duct  520  may include a second flow path  521  configured to guide cool air generated by the second evaporator  435  to be supplied to the upper storage compartment  411 ; and a second cool air discharging port  523  configured to discharge the cool air to the inside of the upper storage compartment  411 . 
     A first evaporator  433  and a first blow fan  437  may be mounted to the first cool air duct  510 , and the first cool air duct  510  may include a first flow path  511  configured to guide cool air generated by the first evaporator  433  to be supplied to the lower storage compartment  413  and a first cool air discharging port  521  configured to discharge the cool air to the inside of the lower storage compartment  413 . 
     A defrost heater  440  may be provided in a lower side of the first evaporator  433 . When an ice or frost is generated in the first cool air discharging port  513  provided in the first cool air duct  510  and thus cool air generated in the first evaporator  433  is prevented from being discharged to the lower storage compartment  413 , the defrost heater  440  may be operated to allow cool air to be smoothly discharged to the lower storage compartment  413  by removing the ice and frost generated in the first cool air discharging port  513 . 
     The first cool air duct  510  provided in the rear side of the lower storage compartment  413  may be provided in the rear side of the first storage compartment  414  and the second storage compartment  415 , respectively. 
     A cool pack  530  in which cold storage material is filled may be provided on an upper surface of the inside of the lower storage compartment  413 , and as illustrated in  FIG. 33 , in a process in which cool air generated by the first evaporator  433  is discharged to the lower storage compartment  413  via the first flow path  511 , the cool pack  530  may store the cold storage energy from the cool air that is passed through the first flow path  511  and discharged via the plurality of the first cool air discharging ports  513 . 
     Particularly; the cool pack  530  may store the cold storage energy from cool air that is discharged from the first cool air discharging port  513  that is placed in the most upper side among the plurality of the first cool air discharging ports  513 . 
     As illustrated in  FIG. 34 , when the defrost heater  440  is operated to remove the ice or frost generated in the first cool aft discharging port  513 , air heated by the defrost heater  440  may be raised due to natural convection and then guided to an upper side of the first flow path  511  of the first cool air duct  510 . 
     Since air guided to the upper side of the first flow path  511  is maintained in a high temperature, an ice or frost generated in the first cool air discharging port  513  may be removed by the air having a high temperature so that cool air is smoothly supplied to the lower storage compartment  413 . 
     Air heated by the defrost heater  440  may be discharged to the lower storage compartment  413  via the first cool air discharging port  513  after removing the ice or frost generated in the first cool air discharging port  513 . 
     Since air heated by the defrost heater  440  is discharged to the lower storage compartment  413  via the first cool air discharging port  513  that is placed in the most upper side among the plurality of the first cool air discharging ports  513  and the cool pack  530  configured store the cold storage energy is disposed on the upper surface of the inside of the lower storage compartment  413 , a temperature of air, which is discharged via the first cool air discharging port  513  that is placed in the most upper side among the plurality of the first cool air discharging ports  513 , may be lowered due to the heat exchange with the cool pack  530 . 
     A temperature of air, which is discharged from the first cool air discharging port  513  that is placed in the most upper side, may be lowered and thus the increase of an internal temperature of the lower storage compartment  413  may be delayed. 
     As illustrated in  FIGS. 35 and 36 , an auxiliary flow path unit  540 , which is communicated with the first cool air discharging port  513  that is placed in the most upper side among the plurality of the first cool air discharging ports  513 , may be provided in a lower side of the cool pack  530 . 
     The auxiliary flow path unit  540  may be provided to be communicated with the first cool air discharging port  513  that is placed in the most upper side among the plurality of the first cool air discharging ports  513  to be adjacent to the cool pack  530 , and the auxiliary flow path unit  540  may include a communicating port  541  communicated with the first cool air discharging port  513 ; a flow path cover  543  extended toward the front side from the communicating port  541  to form an auxiliary flow path  544  through which cool air is passed; and a discharging port  545  provided on a front surface of the flow path cover  543  to allow cool air to be discharged. 
     As illustrated in  FIG. 35 , in a process in which cool air generated by the first evaporator  433  is discharged to the first cool air discharging port  513  via the first flow path  511 , and cool air generated by the first evaporator  433  is discharged to the discharging port  545  via the communicating port  541  and the auxiliary flow path  544 , the cool pack  530  may store the cold storage energy by directly making contact with cool air that is passed through the auxiliary flow path  544 . 
     Since cool air discharged from the first cool air discharging port  513  directly makes contact with the cool pack  530 , the cool pack  530  may more efficiently store the cold storage energy. 
     As illustrated in  FIG. 36 , air heated by the defrost heater  440  may be discharged to the lower storage compartment  413  via the first cool air discharging port  513  after removing the ice or frost generated in the first cool air discharging port  513 . 
     In a state in which air heated by the defrost heater  440  is discharged to the lower storage compartment  413  via the first cool air discharging port  513  that is placed in the most upper side among the plurality of the first cool air discharging ports  513 , since the first cool air discharging port  513  that is placed in the most upper side is communicated with the auxiliary flow path unit  540 , air heated by the defrost heater  440  may directly make contact with the cool pack  530  in a process of being discharged to the discharging port  545  via the first cool air discharging port  513 , the communicating port  541  and the auxiliary flow path  544 . 
     Since heated air directly makes contact with the cool pack  530 , the heat exchange may be effectively performed and thus a temperature of the heated air may be lower than a temperature of a heated air that is not passed through the auxiliary flow path unit  540 . Accordingly, the increase of a temperature of the inside of the lower storage compartment  413  may be effectively delayed. 
     A configuration of the cool pack  530  and a structure in which the cool pack  530  is mounted to an upper surface of the inside of the lower storage compartment  413  may be the same as the cool pack  330  illustrated in  FIGS. 28 and 29 , and thus a description thereof will be omitted. 
     As illustrated in  FIGS. 37 and 38 , an inner case cool pack  550  in which cold storage material is filled may be mounted adjacent to a first flow path  511  of a first cool air duct  510 . 
     The inner case cool pack  550  may be provided in plural, and the inner case cool pack  550  may be mounted to an internal surface of an inner case  401 . 
     A cool pack mounting unit  402  recessed toward the outside may be provided on the internal surface of the inner case  401  to allow the inner case cool pack  550  to be mounted thereto. 
     As illustrated in  FIG. 37 , in a process in which cool air generated by the first evaporator  433  is passed through the first flow path  511 , the inner case cool pack  550  may store the cold storage energy from the cool air. 
     As illustrated in  FIG. 38 , in a process in which air heated by the defrost heater  440  is passed through the first flow path  511 , a temperature of the heated air may be lowered due to the heat exchange with the inner case cool pack  550 . The heated air in a lowered temperature may be discharged to the inside of the lower storage compartment  413  and thus the increase of an internal temperature of the lower storage compartment  413  may be effectively delayed. 
     Although the drawings illustrates that the inner case cool pack  550  is mounted to the internal surface of the inner case  401 , the inner case cool pack  550  may be mounted to an external surface of the inner case  401  so as to be disposed between the inner case  401  and the outer case  403 . 
     As illustrated in  FIGS. 39 and 40 , together with the inner case cool pack  550  mounted to the inner case  401 , a cool pack  530  may be mounted to an upper surface of the inside of the lower storage compartment  413 . 
     As illustrated in  FIG. 39 , in a process in which cool air generated by the first evaporator  433  is passed through the first flow path  511 , the inner case cool pack  550  may store the cold storage energy from the cool air, and the cool pack  530  may store the cold storage energy from cool air discharged via the first cool air discharging port  513 . 
     As illustrated in  FIG. 40 , in a process in which air heated by the defrost heater  440  is passed through the first flow path  511 , a temperature of the heated air may be lowered due to the heat exchange with the inner case cool pack  550 . The heated air in a lowered temperature, which is discharged via the first cool air discharging port  513 , may perform the heat exchange with the cool pack  530  again and thus the temperature of the heated air may be more lowered. Accordingly, the increase of the internal temperature of the lower storage compartment  413  may be more effectively delayed. 
     As is apparent from the above description, according to the proposed refrigerator, it may be possible to delay the increase of the internal temperature of the storage compartment as much as possible, when defrosting is performed. 
     Although a few embodiments of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.