Patent Publication Number: US-2022235994-A1

Title: Supercooling freezer box

Description:
TECHNICAL FIELD 
     The present invention relates to a supercooling refrigerator, and more particularly, to a supercooling refrigerator capable of reducing the frequency of operation of a compressor, reducing an amount of cool air escaping during door opening, and uniformly supplying a low-speed cool air to the interior of the refrigerator. 
     BACKGROUND ART 
     Supercooling refers to a phenomenon in the process of cooling a matter, in which the matter is cooled below a phase change temperature without it undergoing the phase change. Matter has a stable state according to each temperature and when the temperature is gradually changed, the matter follows the change in temperature with the constituent atoms of the matter maintaining the stable state at each temperature. Meanwhile, if there are insufficient nuclei for forming crystals in the matter, the phase change does not occur even when the temperature of the matter is dropped to the phase change temperature or lower. Additionally, when the temperature of the matter changes rapidly, there also occurs a phenomenon in which the constituent atoms maintain the same stable state as they are at the starting point temperature, or some are changed to a state at the end point temperature but then stopped, because the constituent atoms do not have enough time to change to a stable state according to each temperature. 
     That is, when a certain matter in solid state undergoes a change with reference to a certain temperature T as a boundary, that is, when this solid matter is changed to another crystal form of solid or melt to liquid at temperature T 1  (T 1 ≥T), if the matter is rapidly cooled down to a certain temperature below temperature T 1 , the change does not occur, and the matter remains liquid even at the temperature below a freezing point, or the matter maintains the stable crystalline state that it had at the temperature T 1  even though the temperature is lower than the temperature T. This is called supercooling, meaning cooling that occurs extremely quickly. 
     Meanwhile, since an object in the supercooled state is in a so-called metastable state, this object is apt to change from the unstable equilibrium state toward a more stable state even with a slight stimulus. That is, when supercooled liquid is added with a small piece made up of the same components as the liquid or when the liquid is subjected to a slight impact such as sudden shaking, the supercooled liquid starts to solidify immediately, so that the temperature of the liquid is raised to the freezing point and a stable equilibrium state is maintained at that temperature. 
     In recent years, techniques for storing fish, meat, fruits, vegetables and other processed foods using such supercooling phenomenon have been developed. Particularly, technique is receiving increasing attention, which stores beverage such as water or liquor in a supercooled state and then provides the beverage in a slush form to a consumer by pouring the beverage to a cup or applying an impact to the beverage. However, as can be seen from the cooling curve shown in  FIG. 10 , since the matter generally maintains the supercooled state for only a short time, a separate operation is required to keep the food or beverage in a supercooled state for a prolonged time. 
     As an example of a refrigerator using the supercooling phenomenon, a refrigerator is disclosed in Korean Patent Registration Publication No. 10-1205822. 
     As shown in  FIG. 11 , the refrigerator disclosed in Publication described above includes a cooling chamber  2  for accommodating a container P of liquid beverage, a heat exchanger  9  for cooling the air in the cooling chamber  2 , a cooling duct  5  incorporating the heat exchanger  9  therein, an intake port  10  provided in a portion of the cooling duct  5 , a cool air discharge port  12  provided at a position different from the intake port  10  of the cooling duct  5 , a cool air supply duct  6  for circulating air in the cooling chamber  2 , an introducing port  15  provided at one end of the cool air supply duct  6 , a vent hole  20  for blowing air in the cool air supply duct  6  into the cooling chamber  2 , and a fan  16  mounted so as to face the introducing port  15  of the cool air supply duct  6 . In such a refrigerator, the cooling duct  5  is configured to take in the air in the cooling chamber  2  from the intake port  10 , and cool the air at the heat exchanger  9  and then blow out the air through the cool air discharge port  12 , the cool air supply duct  6  is provided in up and down direction of the cooling chamber  2  on a side surface of the cooling chamber  2 , the introducing port  15  faces the cool air discharge port  12  of the cooling duct  5  and also faces the inside the cooling chamber  2 , and the air is taken into the cool air supply duct  6  from the introducing port  15  by the fan  16 . 
     However, above-described the conventional refrigerator is provided with the rotary type fans such as fan blades, which include an intake fan  11  for supplying the air in the cooling chamber  2  to the cooling duct  5 , and the fan  16  for supplying a cool air cooled along the heat exchanger  9  to the cool air supply duct  6 . In the case of such a rotary fan, since the fan is rotated in a specific direction (clockwise or counterclockwise), the direction of the air is biased to one side, which causes uneven distribution of temperature of the cool air according to the positions in the refrigerator. Further, in order to reduce the uneven distribution of the cool air temperature in the refrigerator, the number and arrangement of the vent holes  20  to discharge the cool air into the cooling chamber  2  are adjusted, but with this configuration alone, reduction of the uneven distribution of temperature of the cool air is limited. 
     Further, in the above-described conventional refrigerator, the container P is seated on a flat plate-like shelf plate  3 , but this causes the cool air discharged from the vent holes  20  to be obstructed by the upper and lower surfaces of the shelf plate  3 , resulting in inefficient circulation of cool air in the refrigerator. As a result, uneven distribution of temperature of the cool air occurs according to the positions in the refrigerator. 
     Further, in the above-described conventional refrigerator, the air in the refrigerator is supplied to the cooling duct  5  through the intake fan  11 , and cooled by heat exchange with the heat exchanger  9 , and then passed through cool air supply duct  6  to be directly discharged into the refrigerator through the cool air discharge port  12 . As a result, the cool air, which is dropped in temperature as it is passed through the heat exchanger  9 , has a rising temperature as it is passed through the relatively long cool air supply duct  6 , and this causes an increased temperature difference between the upper and lower parts even inside the refrigerator (for example, when the temperature inside the refrigerator is set to −6° C., the actual temperature of the heat exchanger can be dropped to below −20° C.). As a result, the temperature of the container P is varied depending on the positions in the refrigerator, and the probability of freezing of the container P is increased. Further, since the cool air is directly discharged into the refrigerator through the cool air discharge port  12 , the discharge rate is relatively fast such that an increased amount of cool air escapes to the outside when the user opens the door  7 . 
     As described above, in the supercooling refrigerator, it is important to maintain the temperature inside the refrigerator within an appropriate range so as to keep the stored object in the supercooled state. Therefore, in order to prevent the temperature inside the cooling chamber from rising due to the heat transfer with the outside air or the outflow of cool air during opening and closing of the door, and also to reduce the temperature changes inside the refrigerator, not only a heater, but also a 1 HP or ½ HP over-spec, high capacity compressor is used. Further, the compressor is subjected to frequent ON/OFF. As a result, the conventional supercooling refrigerator makes a considerable noise of 60 db or greater, needs improvement in energy efficiency, and has a short life of the compressor. 
     SUMMARY OF INVENTION 
     Technical Problem 
     The present invention has been made to solve the problems of the related art described above, and it is an object of the present invention to provide a supercooling refrigerator capable of reducing the frequency of operation of the compressor, reducing the amount of cool air escaping when the door is opened, and uniformly supplying low-speed cool air to the interior of the refrigerator. 
     Solution to Problem 
     The supercooling refrigerator  1000  according to an embodiment of the present invention, includes a refrigerator body  100 ; a door  200  for opening and closing one side of the refrigerator body  100 ; an accommodating portion  400  provided inside the refrigerator body  100  and seated with an object M to be stored; a cooling duct  600  including a fan for taking in air in the refrigerator body  100  and discharging the air, and an evaporator  630  for cooling the air discharged from the fan, and a cool air supply duct  700  formed with a cool air discharge port  710  through which the air cooled through the cooling duct  600  is discharged into the refrigerator body  100 , in which the fan is a cross flow fan  620  including a plurality of discs  622 , and a plurality of blades  623  disposed between the discs  622  along outer circumferential surfaces of the discs  622 . 
     In the supercooling refrigerator according to an embodiment of the present invention, a cool air flow rate adjusting unit  730  may be formed on an upstream side of the cool air supply duct  700  through which the cooled air flows, such that a cross sectional area of a flow of the cooled air is narrowed. 
     In the supercooling refrigerator according to the embodiment of the present invention, the accommodating portion  400  may include a plurality of shelves  410  formed by wires crossed with each other, and shelf supports  420  for supporting the shelves  410 , and a cold insulator  430  is inserted into the wires. 
     In the supercooling refrigerator according to the embodiment of the present invention, the evaporator  630  may include a refrigerant flow pipe  631  through which a refrigerant is moved, and a cold insulation member  632  fitted onto the refrigerant flow pipe  631  and supported thereon. 
     In the supercooling refrigerator according to the embodiment of the present invention, the cool air supply duct  700  may include a cool air discharge mesh  720  attached to the cool air discharge port  710  in a direction of the door  200 . 
     In the supercooling refrigerator according to the embodiment of the present invention, the door  200  may include a plurality of glasses  210  stacked on each other with a spacer  220  interposed therebetween, and a heat insulating gas may be sealed in the spacer  220 . 
     In addition, the supercooling refrigerator according to the embodiment of the present invention may additionally include a machine chamber  300  installed in a side of the refrigerator body  100  to drive a cooling cycle of the supercooling refrigerator  1000 , in which, during defrosting, the machine chamber  300  may defrost the evaporator  630  using a hot gas defrosting method, and defrosted water may be collected into a water collector  310  provided in the machine chamber  300  and evaporated. 
     Advantageous Effects of Invention 
     According to the present invention, it is possible to provide a supercooling refrigerator capable of reducing the frequency of operation of a compressor, reducing an amount of cool air escaping during door opening, and uniformly supplying low-speed cool air into the interior of the refrigerator. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view showing a supercooling refrigerator according to an embodiment of the present invention. 
         FIG. 2  is a front view showing a supercooling refrigerator according to an embodiment of the present invention. 
         FIG. 3  is a side view showing a supercooling refrigerator according to an embodiment of the present invention. 
         FIG. 4  is a detailed view showing a door according to an embodiment of the present invention. 
         FIG. 5  is a detailed view showing a shelf according to an embodiment of the present invention, in which  FIG. 5( a )  is a perspective view showing a shelf and  FIG. 5( b )  is a cross-sectional view showing a first wire forming a shelf. 
         FIG. 6  is a block diagram showing a controller according to an embodiment of the present invention. 
         FIG. 7  is a detailed view showing a cross flow fan according to an embodiment of the present invention, in which  FIG. 7( a )  is a side view showing a cross flow fan, and  FIG. 7( b )  is a front view showing a cross flow fan. 
         FIG. 8  is a detailed view showing an evaporator according to an embodiment of the present invention, in which  FIG. 8( a )  shows an evaporator in which a cylindrical cold insulation member is fitted,  FIG. 8( b )  shows an evaporator in which a cold insulation member of a rectangular parallelepiped shape is fitted, and  FIG. 8( c )  shows an evaporator in which a ring-shaped cold insulation member is fitted. 
         FIG. 9  is a detailed view showing a cool air discharge port and a cool air discharge mesh according to an embodiment of the present invention. 
         FIG. 10  is a view showing an ideal cooling curve. 
         FIG. 11  is a view showing a conventional supercooling refrigerator. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Hereinafter, a supercooling refrigerator  1000  according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. 
       FIG. 1  is a perspective view showing a supercooling refrigerator according to an embodiment of the present invention, and  FIG. 2  is a front view showing a supercooling refrigerator according to an embodiment of the present invention. For reference, in  FIG. 1 , a side where a door  200  is installed is defined as a front, and with reference to this, a front and back direction, an up and down direction, and a left and right direction are defined. The front and back direction corresponds to a longitudinal direction of the supercooling refrigerator  1000 , and the up and down direction corresponds to a height direction of the supercooling refrigerator  1000 , and the left and right direction corresponds to a width direction of the supercooling refrigerator  1000 , respectively. 
     As shown in  FIGS. 1 and 2 , the supercooling refrigerator  1000  according to an embodiment of the present invention includes a refrigerator body  100 , a door  200 , a machine chamber  300 , an accommodating portion  400 , and a controller  500 . The refrigerator body  100  may have various shapes, and in one embodiment of the present invention, the refrigerator body  100  has a rectangular parallelepiped shape. An object M is accommodated inside the refrigerator body  100 . The object M includes meat, fish, vegetables, fruits, beverages, liquors and other processed foods. 
     The supercooling refrigerator  1000  according to an embodiment of the present invention may be set so as to maintain the temperature in the refrigerator from −6° C. to −6.5° C. with a deviation of about +3° C., and cause 80 to 120 bottles of carbonated drink or beer having a temperature of 20° C. or higher at room temperature to reach a supercooling state at the elapse of 6 hours after the start of cooling. In addition, the supercooling refrigerator  1000  may be set so as to keep the temperature in the refrigerator at −0.5° C. with a deviation of about +0.5° C., and store raw meat in a non-frozen state. However, the usage of the supercooling refrigerator  1000  is not limited to these applications only, and the various types of objects M described above may be kept in supercooled state, by appropriately varying the setting state of the supercooling refrigerator  1000  accordingly. 
     The door  200  is provided on one side of the refrigerator body  100 . The door  200  is configured such that a user may open and close the door  200  while holding a handle (not shown) installed on one side of the door  200 . The door  200  is formed of a plurality of layers of transparent glass so that the internal state of the supercooling refrigerator  1000  may be checked from the outside even when the door  200  is closed. Details of the door  200  will be described below. 
     The machine chamber  300  is formed in the lower portion of the refrigerator body  100 . The machine chamber  300  includes members for operating the cooling cycle of the supercooling refrigerator  1000 . Details of the machine chamber  300  will be described below. 
     The accommodating portion  400  for the object M to be seated thereon is installed in the interior of the refrigerator body  100 . The accommodating portion  400  includes a plurality of shelves  410  and a plurality of shelf supports  420  supporting the shelves  410  (see  FIG. 3 ). The plurality of shelves  410  are installed at intervals from each other in the height direction of the supercooling refrigerator  1000 . The shelf  410  is configured such that the metal wires cross each other to form a framework of a rectangular parallelepiped shape, and the object M is inserted through an upper open side of the shelf  410 . The plurality of shelf supports  420  are respectively provided on both side surfaces of the interior of the refrigerator body  100  to support both sides of the plurality of shelves  410 . A height adjusting member is provided on the shelf support  420  so as to appropriately adjust a distance between the shelves  410  in consideration of the object M to be seated. Details of the shelf  410  will be described below. 
     As shown in  FIG. 1 , a controller  500  is formed on one side of an upper portion of the refrigerator body  100 , and the controller  500  operates to control the current state of the supercooling refrigerator  1000  automatically or manually. Details of the controller  500  will be described below. 
       FIG. 3  is a side view showing a supercooling refrigerator according to an embodiment of the present invention. 
     A heat insulator  110  is provided between outer and inner walls of the refrigerator body  100  to prevent heat transfer from occurring due to temperature difference between the interior and exterior of the supercooling refrigerator  1000 . For the heat insulator, a cyclopentane foaming agent may be used, for example. 
     A cooling duct  600  is provided on an upper side of the interior of the refrigerator body  100  and an intake port  610  is formed on one side of the cooling duct  600  toward the direction of the door  200 . A cross flow fan  620  and an evaporator  630  are installed inside the cooling duct  600 , respectively. Further, an introducing port  640  is formed at one side of the cooling duct  600  opposite the door  200 , and connected to a cool air supply duct  700  to be described below. 
     When the cross flow fan  620  is operated, the air inside the refrigerator body  100  is taken in through the intake port  610 , and the intake air passes through the cross flow fan  620  and then through the evaporator  630 . The air is deprived of heat by heat exchange with the evaporator  630  as passing through the evaporator  630  to be turned into a low temperature cool air, and the cool air is introduced into the cool air supply duct  700  through the introducing port  640 . Details of the cross flow fan  620  and the evaporator  630  will be described below. 
     A cool air supply duct  700  is provided on a rear surface of the interior of the refrigerator body  100 . One side of an upper portion of the cool air supply duct  700  is opened to be connected to the introducing port  640  of the cooling duct  600 . A plurality of cool air discharge ports  710  are formed in the cool air supply duct  700  toward the direction of the door  200 . In addition, a cool air discharge mesh  720  is attached to the cool air discharge port  710  toward the direction of the door  200 , and the cool air that passed through the evaporator  630  is supplied to the interior of the refrigerator body  100  through the cool air discharge port  710  and the cool air discharge mesh  720 . Details of the cool air discharge port  710  and the cool air discharge mesh  720  will be described below. 
     In addition, a cool air flow rate adjusting unit  730  is formed on one side of the upper portion of the cool air supply duct  700 . The cool air flow rate adjusting unit  730  is a member such as a nozzle that increases the flow rate of the cool air by narrowing a cross-sectional area of a flow of the cool air passing through the cool air supply duct  700 . In the present embodiment, protrusions are formed on an inner surface of the cool air supply duct  700  to narrow flow cross-sectional area of the flow of the cool air. Accordingly, the flow rate of cool air passing through the cool air flow rate adjusting unit  730  is increased, and the time for the cool air to reach the lowermost portion of the cool air supply duct  600  is shortened. Therefore, the temperature difference according to the height in the interior of the refrigerator body  100  may be reduced. 
     The machine chamber  300  is provided in a lower portion of the refrigerator body  100 . A driving apparatus for driving the evaporator  630  is installed in the machine chamber  300 . Specifically, the driving apparatus includes an apparatus that forms a cooling cycle in cooperation with the evaporator  630 , such as a compressor that compresses the high-temperature refrigerant that has passed through the evaporator  630 , a condenser that takes heat from the refrigerant discharged from the compressor to convert the refrigerant into a liquid state, an expansion valve that converts the liquid refrigerant into a two-phase state, a cooling fan that cools down the condenser and the compressor, and the like. The position of the machine chamber  300  is not limited to the lower portion of the refrigerator body  100  and may be provided at an upper portion of the refrigerator body  100 , in which case the distance to the evaporator  630  is shortened. The compressor, the condenser, the expansion valve, the cooling fan, and the like may be of any known configuration, and a detailed description thereof will be omitted. 
     In addition, a water collector  310  is installed in the machine chamber  300 . The supercooling refrigerator  1000  according to the embodiment of the present invention does not include a separate defrost heater for defrosting the evaporator  630 , unlike the conventional supercooling refrigerator. Instead, hot-gas defrosting method is employed, which reversely operates the cooling cycle to cause the refrigerant in a relatively high temperature state to flow to the evaporator  630  to remove the frost formed on the surface of the evaporator  630 . In this process, the frost which is adhered onto the evaporator  630  is melted, generating water, and the generated water is collected in the water collector  310  of the machine chamber  300  through a drain plate installed at one side of the refrigerator body  100 . The water collected in the water collector  310  evaporates due to the heat of the condenser installed inside the machine chamber  300 , the wind from the cooling fan, and the like. 
     More specifically, when the fan installed in the condenser inside the machine chamber  300  is driven, outside air flows into the machine chamber  300  through a heat sink (see  FIG. 1 ) attached to the outer wall of the machine chamber  300 . The introduced outside air cools the condenser and the compressor in turn. The outside air whose temperature has risen due to the heat from the condenser and the compressor evaporates the defrost water of the water collector  310  and is then discharged to the outside through a rear surface of the machine chamber  300 . 
     With the configuration described above, the supercooling refrigerator  1000  according to an embodiment of the present invention may reduce the electricity consumption by using the hot-gas defrosting method instead of employing a separate defrost heater to remove the frost of the evaporator  630 . In addition, since the water collected in the water collector  310  is naturally evaporated in the machine chamber  300  without having to separately remove the water, the structure is simpler than the conventional supercooling refrigerator which required that a water collector be separately installed outside the refrigerator and should be periodically managed, while inconvenience in use is also reduced. 
     The sensor  800  may be installed in the supercooling refrigerator  1000  according to the present embodiment. The sensor  800  senses the internal temperature of the supercooling refrigerator  1000 , a degree of occupancy by the object M, whether the door  200  is open or closed, a flow rate of the cool air, and the like. Specifically, the sensor  800  may be installed on a bottom surface of the shelf  410  to measure the degree of occupancy by the object M by measuring the weight of the object M, may be installed on one side of the shelf support  420  to measure temperature, may be installed on one side of the door  200  to detect whether the door  200  is open or closed, and may be installed on one side of the intake port  610  and the introducing port  640  of the cooling duct  600  or inside the cool air supply duct  700  to measure the flow rate of the cool air. The mounting position of the sensor  800  is not particularly limited, and may be any position as long as the current state of the supercooling refrigerator  1000  can be easily sensed. In addition, the sensor  800  is connected to the controller  500  described above. Accordingly, data on the current state of the supercooling refrigerator  1000  measured or sensed by the sensor  800  is transmitted to the controller  500 . 
       FIG. 4  is a detailed view showing a door according to an embodiment of the present invention. 
     Referring to  FIGS. 1 and 4 , the door  200  has a plurality of glass  210  stacked in several layers in a longitudinal direction of the refrigerator body  100 . In an embodiment of the present invention, two-fold or three-fold glasses  210  are stacked. For the glass  210 , it is preferable to use tempered glass or safety glass having a higher strength than ordinary glass. The thickness of each glass  210  is not particularly limited, and in an embodiment of the present invention, the interval between respective glasses  210  is about 7 mm. A spacer  220  is formed between the respective glasses  210 , and a heat insulator is inserted into the spacer  220  to minimize heat transfer that is caused by a temperature difference between the inside and outside of the supercooling refrigerator  1000 . In one embodiment of the present invention, argon (Ar) gas, krypton (Kr) gas or nitrogen (N 2 ) gas serves as a heat insulator, and the argon gas, the krypton gas or the nitrogen gas is enclosed in the spacer  220 . By enclosing the argon gas, the krypton gas or the nitrogen gas having a low thermal conductivity in the spacer  220 , heat transfer inside and outside of the supercooling refrigerator  1000  may be suppressed to suppress the condensation phenomenon and the cold radiation phenomenon, and enhance the heat insulation performance. An anti-frost film  230  is attached to the inner glass  210  of the glasses  210 . Further, a metal or a metal oxide may be thinly coated on one surface of the glasses  210  to further reduce the heat transfer. 
       FIG. 5  is a detailed view showing a shelf according to an embodiment of the present invention. 
     The shelf  410  is configured with a plurality of metal wires crossing each other to form a framework of a rectangular parallelepiped shape. The metal wires forming the shelf  410  include a first wire  411 , and a second wire  412  having a smaller diameter than the first wire  411 . The first wire  411  includes a frame wire forming the framework of the rectangular parallelepiped shape of the shelf  410 , and a guide wire compartmenting the shelf  410  in the width direction of the supercooling refrigerator  1000 . The guide wire serves to compartment the shelf  410  into regions for the object M to be seated and also to prevent the object M from collapsing or freezing due to external impact or internal vibration. The number of the guide wires is not particularly limited, and in this embodiment, the guide wires are configured such that the objects M may be arranged in six rows when viewed from the front. A plurality of second wires  412  are provided between the first wires  411  located on the bottom surface of the shelf  410  to forma bottom of the shelf  410 . The object M is inserted through the upper side of the shelf  410  and is supported by the second wire  412 . 
     That is, unlike the flat or box-shaped shelves employed in the conventional supercooling refrigerator, the shelf  410  according to the embodiment of the present invention is formed such that the metal wires cross each other, and thus all the sides where the object M and cool air are in contact with each other are open. Therefore, one of the problems of the conventional supercooling refrigerator, that is, the phenomenon in which the cool air is hit against the shelf and reduced in speed, that leads into accumulation of the cool air, is prevented, and the contact area between the object M and cool air may be widened. Particularly, since the bottom side of the shelf  410  is also formed of the second wires  412  rather than as a flat plate, the contact area between the bottom surface of the object M and the cool air may be maximized, thus resulting in further increased cooling efficiency. 
     In addition, the cold insulator  430  is inserted into the first wire  411 . The cold insulator  430  is kept in a solid state in the operating temperature range of the supercooling refrigerator  1000 , and when the user opens the door  200 , allowing the outside air to flow into the interior of the supercooling refrigerator  1000 , the cold insulator  430  inserted into the first wire  411  absorbs the heat of the outside air to minimize the temperature change inside the supercooling refrigerator  1000 . 
     This temperature maintaining effect of the cold insulator  430  will be described in more detail as follows. For example, when the width of the shelf  410  is set to 520 mm, the length is set to 550 mm, and the height is set to 100 mm, and there are a total of four shelves  410  provided in the height direction of the supercooling refrigerator  1000 , and the diameter of the first wire  411  is set to 10 mm, and the interior of the first wire  411  is filled with the cold insulator  430 , the total volume of the cold insulator  430  inserted into the entire shelf  410  is calculated as follows. 
     Total volume of the cold insulator  430  inserted into the upper and lower sides of each shelf  410 =(7×550+2×520)×π/4×10 2 ×2≈768.12 cm 3    
     Total volume of the cold insulator  430  inserted into the front and rear sides of each shelf  410 =7×100×π/4×10 2 ×2≈109.96 cm 3    
     Total volume of the cold insulator  430  inserted into the entire shelf  410 ≈(768.12+109.96)×4=3512.32 cm 3    
     Accordingly, when compared to an ice pack having a volume of 200 cm 3 , the shelf  410  according to an embodiment of the present invention has a heat capacity corresponding to about 17.56 ice packs. Accordingly, even when the cooling cycle of the supercooling refrigerator  1000  does not operate, the low temperature state may be maintained for a long time, and the operating frequency of the cooling cycle, that is, the frequency of operating the compressor may be reduced, thereby increasing the service life of the compressor. In the embodiment of the present invention, the cold insulator  430  is inserted into the first wire  411 , but is not limited thereto, and the cold insulator  430  may also be inserted into the second wire  412 . Further, the dimensions of the shelf  410  may be appropriately changed in consideration of the purpose of use of the supercooling refrigerator  1000  and the like. 
       FIG. 6  is a block diagram showing a main configuration of a controller according to an embodiment of the present invention. 
     In the present embodiment, the controller  500  is attached to the upper portion of the refrigerator body  100 , but is not limited thereto, and the controller  500  may be attached to a position that is easy for the user to operate or check. As described above, the controller  500  controls the current state of the supercooling refrigerator  1000  and is connected to the sensor  800 . The controller  500  includes a power supply  510  capable of turning on and off the power of the supercooling refrigerator  1000 , an input unit  520  that receives, from the sensor  800 , data on the current state of the supercooling refrigerator  1000  (internal temperature, weight of the object M being accommodated, whether the door  200  is open or closed, flow rate of cool air, and the like), a display unit  530  indicating the current state of the supercooling refrigerator  1000 , a calculation unit  540  that determines whether it is necessary to change the internal state of the supercooling refrigerator  1000  based on the received data, and an adjusting unit  550  that adjusts the internal temperature, the flow rate of cool air, and the like of the supercooling refrigerator  1000 . In addition, the user may manually adjust the internal state of the supercooling refrigerator  1000  by inputting a desired temperature range or the like using an input panel (not shown) of the controller  500 . 
       FIG. 7  is a detailed view showing a cross flow fan according to an embodiment of the present invention. 
     Referring to  FIGS. 3 and 7 , the cross flow fan  620  is installed inside the cooling duct  600  to take in air from the intake port  610  of the cooling duct  600  to generate a flow. The cross flow fan  620  includes a housing  621 , discs  622 , blades  623 , a guide plate  624 , and a fan motor  625 . 
     The housing  621  is supported on both inner sides of the refrigerator body  100  and serves to accommodate and support the other members forming the cross flow fan  620 . The disc  622  is a disc-shaped member, and a plurality of discs  622  are provided inside the housing  621  at predetermined intervals. A plurality of blades  623  serving as blowing blades of the cross flow fan  620  are provided between the respective discs  622 . Each of the blades  623  is installed in a ring shape at predetermined intervals along a circumferential direction of the disc  622 . A plurality of guide plates  624  are provided on the inner side of the blades  623 , and form a flow path so that the intake air from one side of the cross flow fan  620  is discharged to the other side. The guide plates  624  are spaced apart from each other by a predetermined distance, and are bent to allow air to smoothly flow. The guide plate  624  is fixed to the housing  621  by a support member (not shown) and is not rotated by the operation of a fan motor  625  to be described below. The disc  622 , the blade  623 , and the guide plate  624  form one unit, and a plurality of units are coupled to each other in an axial direction. The fan motor  625  is coupled to one end of the cross flow fan  620  to drive the cross flow fan  620 . The discs  622  and the blades  623  are axially rotated while being supported by the housing  621  in accordance with the operation of the fan motor  625 . 
     As described above, the supercooling refrigerator  1000  according to the embodiment of the present invention employs the cross flow fan  620 , unlike the conventional supercooling refrigerator using the rotary fan such as the fan blades. As a result, the air that has passed through the cross flow fan  620  is uniformly supplied to the evaporator  630  without being biased to one side and likewise, the cool air having passed through the evaporator  630  may pass through the cool air supply duct  700  to be uniformly discharged through the cool air discharge port  710 . 
       FIG. 8  is a detailed view showing an evaporator according to an embodiment of the present invention. 
     The evaporator  630  according to one embodiment of the present invention includes a refrigerant flow pipe  631  through which a refrigerant moves, and a cold insulation member  632  fitted onto the refrigerant flow pipe  631  and supported thereon. 
     The cold insulator inserted into the cold insulation member  632  is maintained in solid state during operation of the supercooling refrigerator  1000  of the present invention. As shown in  FIGS. 8( a ) to 8( c ) , the shape of the cold insulation member  632  may be a hollow cylindrical shape that covers the refrigerant flow pipe  631  in the axial direction or may be a block or a ring shape that is fitted onto the refrigerant flow pipe  631  and supported thereon. The shape and the number of the cold insulation member  632  are not particularly limited and may be appropriately employed in consideration of the shape of the evaporator  630  or the operating environment of the supercooling refrigerator  1000 . 
     With this configuration, in the supercooling refrigerator  1000  according to an embodiment of the present invention, during operation of the cooling cycle, the cold insulation member  632  is maintained in a low temperature state through heat exchange with the evaporator  630 , and when the cooling cycle is stopped, the cold insulation member  632  emits cool air to suppress the temperature rise in the supercooling refrigerator  1000 . Thus, the frequency of operation of the cooling cycle, that is, the frequency of operation of the compressor may be reduced, thereby extending the service life of the compressor. 
       FIG. 9  is a detailed view showing a cool air discharge port and a cool air discharge mesh according to an embodiment of the present invention. 
     Referring to  FIGS. 3 and 9 , a plurality of cool air discharge ports  710  are formed on one surface of the cool air supply duct  700  toward the direction of the door  200 , and are distributed in vertical and horizontal directions. The cool air introduced into the cool air supply duct  700  through the cooling duct  600  is discharged to the interior of the refrigerator body  100  through the cool air discharge port  710 . 
     Meanwhile, in the supercooling refrigerator  1000  according to the embodiment of the present invention, the cool air discharge mesh  720  is attached to the surface of the cool air supply duct  700  that is formed with the cool air discharge port  710 . The cool air discharge mesh  720  is a fiber paper having a large number of fine holes formed therein, and may be formed of Korean paper, for example. As a result, the cool air cooled through the cooling duct  600  is discharged into the refrigerator body  100  through the cool air discharge port  710  and the cool air discharge mesh  720 , instead of being directly discharged into the refrigerator body  100  through the cool air discharge port  710 . Since a large number of fine holes are formed in the cool air discharge mesh  720 , the cool air may be discharged uniformly and the discharging rate may be reduced as compared with the case where the cool air is directly discharged into the refrigerator body  100  through only the cool air discharge port  710 . Therefore, the uneven distribution of the temperature inside the refrigerator body  100  may be reduced, and when the user opens the door  200 , the amount of cool air escaping outside may be reduced. 
     Hereinafter, a method of operating the supercooling refrigerator  1000  according to an embodiment of the present invention will be described with reference to  FIGS. 1 to 9 . 
     First, the user places the object M in the accommodating portion  400  of the supercooling refrigerator  1000  and, using the controller  500 , sets an appropriate temperature, wind intensity, and the like in accordance with the object M. Next, when the supercooling refrigerator  1000  is operated, the compressor, the condenser, the expansion valve, and the like of the machine chamber  300  are operated, and the evaporator  630  of the cooling duct  600  is also operated, and likewise, in response to the operation of the fan motor  625 , the cross flow fan  620  is operated. When the cross flow fan  620  is operated, air in the refrigerator body  100  is taken into the cross flow fan  620  through the intake port  610  of the cooling duct  600  and then discharged to the evaporator  630 . The cool air, which has been deprived of heat as passing through the evaporator  630  and is cooled to a low temperature, is moved to the cool air supply duct  700 . In this process, since the cool air passing through the cross flow fan  620  is not biased to one side and is moved evenly, the uneven distribution of temperature in the interior of the refrigerator may be reduced as compared with the conventional supercooling refrigerator using the rotary fan. 
     As the cool air is passed through the cool air flow rate adjusting unit  730  formed at one side of the upper portion of the cool air supply duct  700 , the flow rate is increased. With this configuration, the cool air may be rapidly moved to the lower portion of the cool air supply duct  700 , so that the uneven distribution of temperature in the height direction inside the refrigerator may be further reduced as compared with the conventional supercooling refrigerator. 
     The cool air reaching the cool air supply duct  700  is discharged into the interior of the refrigerator body  100  through the cool air discharge port  710 . In this process, due to the cool air discharge mesh  720  attached to one side of the cool air discharge port  710  toward the direction of the door  200 , and a large number of fine holes formed in the cool air discharge mesh  720 , the cool air may be uniformly discharged at a lower speed. With this configuration, the cool air may be discharged more uniformly, and particularly, the speed of the cool air may be effectively reduced as compared with the case where the cool air is discharged through only the cool air discharge port  710 , so that the amount of cool air that escapes to the outside when the user opens the door  200  can be reduced. 
     That is, the cool air is supplied more quickly by using the cool air flow rate adjusting unit  730  of the cool air supply duct  700 , so that the uneven distribution of temperature of the cool air according to the height is reduced, and the flow rate of the cool air thus accelerated is effectively reduced using the cool air discharge mesh  720  again. The cool air discharged through the cool air discharge mesh  720  uniformly spreads inside the refrigerator body  100  to efficiently cool the object M and to keep the object (M) in the supercooled state. 
     Further, since the shelf  410  of the accommodating portion  400  on which the object M is seated is formed of wires unlike the conventional plate-type shelves of the supercooling refrigerator, the contact area between the cool air and the object M may be increased, resulting in increased cooling efficiency. Further, the bottom of the shelf  410  is also formed of wires rather than as a flat plate, so that the bottom surface of the object M may also be effectively cooled, thereby further increasing the cooling efficiency. 
     In addition, the cold insulator  430  is inserted into the wires forming the shelf  410 , so that, even when the cooling cycle does not operate, the change in the internal temperature of the refrigerator body  100  may be made gentle with the cool air stored in the cold insulator  430  of the low temperature. With this configuration, the operating frequency of the cooling cycle, that is, the operating frequency of the compressor may be lowered, thereby increasing the service life of the compressor, which is also effective in reducing power consumption and noise. 
     In addition, the shelf  410  is provided with guide wires that divide the objects M in the width direction so that the objects M can be prevented from collapsing, or freezing due to an external impact or internal vibrations. 
     In addition, the cold insulation member  632  is also attached to the refrigerant flow pipe  631  of the evaporator  630 . Therefore, as in the case of the cold insulator  430  of the shelf  410 , even when the cooling cycle does not operate, the change in the internal temperature of the refrigerator body  100  may be made gentle with the cool air stored in the cold insulation member  632  of the low temperature. With this configuration, the operating frequency of the cooling cycle, that is, the operating frequency of the compressor may be lowered, so that the life of the compressor may be further increased, and the power consumption and the noise may be further effectively reduced. 
     Further, the door  200  is formed of double glasses  210  with a spacer  220  interposed therebetween, and the argon gas, the krypton gas or the nitrogen gas is enclosed in the spacer  220  to reduce the heat transfer according to the temperature difference between the inside and the outside of the supercooling refrigerator  1000 , thereby preventing the condensation phenomenon. With this configuration, unlike the conventional supercooling refrigerator, it is not necessary to provide a separate defrost heater in the door  200 , so that the configuration may be simplified and power consumption may be reduced. 
     Further, unlike a conventional supercooling refrigerator in which a separate heater is installed in the evaporator  630  for defrosting, the supercooling refrigerator  1000  according to the present invention employs the hot-gas defrosting method that reversely drives the cooling cycle to perform defrosting using a relatively high-temperature refrigerant, so that power consumption may be reduced. In addition, the water generated after the defrosting is collected in the water collector  310  of the machine chamber  300  and then naturally evaporated by the heat and wind generated during driving the cooling cycle, thereby simplifying the structure and reducing inconvenience in use as compared with the conventional supercooling refrigerator. 
     That is, the supercooling refrigerator  1000  according to the present invention may reduce the frequency of operating the cooling cycle (compressor) to thus increase the service life of the compressor, and may employ a small compressor (for example, a ⅕ horsepower or a ⅓ horsepower compressor) instead of a conventional large capacity compressor to thus reduce power consumption and noise. Further, the supercooling refrigerator  1000  according to the present invention may reduce the amount of cool air escaping when the door is opened, uniformly supply the low-speed cool air to the interior of the refrigerator, and does not employ a heater to thus further reduce power consumption. 
     Note that, in the supercooling refrigerator  1000  according to the embodiment of the present invention, it is described that there is one door  200 , but the present invention is not limited thereto. For example, a plurality of the doors  200  may be formed to correspond to each position of the plurality of shelves  410 . With this configuration, user can selectively open and close only the door  200  corresponding to the shelf  410  on which the desired object M is seated, and in this case, the amount of cool air escaping outside may be further reduced. Further, a cool air escape preventing curtain formed of acrylic, vinyl resin material or the like may be formed between the refrigerator body  100  and the door  200 , so that the amount of cool air escaping outside may be further reduced. 
     In addition, in the supercooling refrigerator  1000  according to the embodiment of the present invention, it is described that the vibrations or shocks applied to the object M in the shelf  410  are suppressed by the guide wires, but the present invention is not limited thereto. For example, in addition to the guide wires, by adding an anti-vibration member formed of rubber or the like to a coupling portion of the shelf  410  and the shelf support  420 , the vibrations or shocks applied to the object M seated on the shelf  410  may further be suppressed. 
     Further, in the supercooling refrigerator  1000  according to the embodiment of the present invention, it is described that the objects M seated on the shelf  410  are adjacent to each other in the width direction, but the present invention is not limited thereto. For example, the guide wires may be wider or a plurality of guide wires may be provided between the objects M in the width direction so that the objects M are spaced apart from each other in the width direction. With this configuration, the contact area between the object M and cool air may be widened, resulting in further enhanced cooling efficiency. 
     The present invention has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given byway of illustration only, since various changes and modifications within the scope of the present invention will become apparent to those skilled in the art from this detailed description. Accordingly, the embodiments disclosed in the present invention are provided to explain, not to limit a technical art of the present invention, and thus, the scope of the present invention is not limited. A scope of a protection of the present invention should be construed by following claims, and every technical art within a same scope of the following claims should be construed to be included in a scope of a right of the present invention. 
     DESCRIPTION OF REFERENCE NUMERALS 
     
         
           100 : refrigerator body 
           110 : heat insulator 
           200 : door 
           210 : glass 
           220 : spacer 
           230 : anti-frost film 
           300 : machine chamber 
           310 : water collector 
           400 : accommodating portion 
           410 : shelf 
           411 : first wire 
           412 : second wire 
           420 : shelf support 
           430 : cold insulator 
           500 : controller 
           510 : power supply 
           520 : input unit 
           530 : display unit 
           540 : calculation unit 
           550 : adjusting unit 
           600 : cooling duct 
           610 : intake port 
           620 : cross flow fan 
           621 : housing 
           622 : disc 
           623 : blade 
           624 : guide plate 
           625 : fan motor 
           630 : evaporator 
           631 : refrigerant flow pipe 
           632 : cold insulation member 
           640 : introducing port 
           700 : cool air supply duct 
           710 : cool air discharge port 
           720 : cool air discharge mesh 
           730 : cool air flow rate adjusting unit 
           800 : sensor 
           1000 : supercooling refrigerator