Direct cooling refrigerator and control method thereof

Abstract

A direct cooling refrigerator having a circulation duct. The direct cooling refrigerator includes a cabinet, an inner case arranged in the cabinet and having an inlet and an outlet, a circulation duct coupled to the inner case at the outside of the inner case and having a suction port communicating with the outlet and a discharge port communicating with the inlet, and a fan to move air from the suction port to the discharge port within the circulation duct. The inlet is located at an upper wall of the inner case so as to be located closer to a front surface of the inner case than a rear wall of the inner case, and the outlet is located at the rear wall of the inner case so as to be located close to a lower wall of the inner case.

What is claimed is: 
     
         1 . A direct cooling refrigerator comprising:
 a cabinet;   an inner case arranged in the cabinet and having an inlet and an outlet;   a circulation duct coupled to the inner case at the outside of the inner case and having a suction port communicating with the outlet and a discharge port communicating with the inlet; and   a fan to move air from the suction port to the discharge port within the circulation duct,   wherein the inlet is located at an upper wall of the inner case so as to be located closer to a front surface of the inner case than a rear wall of the inner case, and   wherein the outlet is located at the rear wall of the inner case so as to be located close to a lower wall of the inner case.   
     
     
         2 . The refrigerator according to  claim 1 , wherein the fan is located at the outside of the upper wall of the inner case. 
     
     
         3 . The refrigerator according to  claim 1 , wherein the fan is spaced apart from the discharge port by a predetermined distance rearward of the inner case. 
     
     
         4 . The refrigerator according to  claim 1 , wherein the fan is a centrifugal fan to discharge air in a radial direction thereof. 
     
     
         5 . The refrigerator according to  claim 1 , further comprising an evaporator to cool a storage compartment,
 wherein the evaporator is arranged close to a left wall, a right wall and the lower wall of the inner case.   
     
     
         6 . A direct cooling refrigerator comprising:
 a cabinet;   a storage compartment defined in the cabinet;   an inner case in which the storage compartment is defined, the inner case having an opening at a front surface thereof; and   a circulation duct arranged at the outside of the inner case to communicate with the inner case so as to circulate air of the storage compartment.   
     
     
         7 . The refrigerator according to  claim 6 , wherein the circulation duct extends from the outside of a rear wall of the inner case to the outside of an upper wall of the inner case. 
     
     
         8 . The refrigerator according to  claim 6 , wherein the circulation duct includes a suction path into which the air of the storage compartment is suctioned, a discharge path from which the air is discharged into the storage compartment and a fan mounting region located between the suction path and the discharge path. 
     
     
         9 . The refrigerator according to  claim 8 , wherein the circulation duct further includes a fan mounted in the fan mounting region to move the air from the suction path to the discharge path. 
     
     
         10 . The refrigerator according to  claim 8 , wherein the fan mounting region has an open bottom to allow the fan to be installed therein. 
     
     
         11 . The refrigerator according to  claim 8 , wherein the discharge path is located at the outside of an upper wall of the inner case to guide the air in a longitudinal direction of the upper wall of the inner case. 
     
     
         12 . The refrigerator according to  claim 6 , further comprising an evaporator to cool the storage compartment,
 wherein the evaporator is arranged close to a left wall, a right wall and a lower wall of the inner case.   
     
     
         13 . A direct cooling refrigerator comprising:
 a cabinet;   an inner case arranged in the cabinet and having an opening at a front surface thereof;   a storage compartment defined in the inner case;   a door slidably coupled to the inner case to open or close the opening;   an outlet formed in a rear wall of the inner case, through which air is discharged from the storage compartment;   an inlet formed in an upper wall of the inner case, through which air is suctioned into the storage compartment;   a circulation duct arranged at the outside of the inner case and having a suction port communicating with the outlet and a discharge port communicating with the inlet; and   a fan arranged around the discharge hole to move air within the circulation duct.   
     
     
         14 . A control method of a direct cooling refrigerator comprising:
 sensing temperature of an evaporator using an evaporator sensor installed to the evaporator;   sensing interior temperature of the refrigerator using a temperature sensor; and   controlling On/Off operations of a cooling system and a fan based on the sensed temperature of the evaporator and the sensed interior temperature of the refrigerator, enabling natural defrosting of the evaporator.   
     
     
         15 . The control method according to  claim 14 , wherein the evaporator sensor is closely attached to the evaporator without a gap. 
     
     
         16 . The control method according to  claim 14 , wherein controlling On/Off operations of the cooling system and the fan based on the sensed temperature of the evaporator and the sensed interior temperature of the refrigerator includes controlling the cooling system and the fan to be turned on only when the temperature sensed by the evaporator sensor is equal to or greater than a predetermined reference temperature. 
     
     
         17 . The control method according to  claim 14 , wherein controlling On/Off operations of the cooling system and the fan based on the sensed temperature of the evaporator and the sensed interior temperature of the refrigerator includes starting a cooling operation when the interior temperature of the refrigerator sensed by the temperature sensor reaches an On temperature of the temperature sensor if the interior temperature of the refrigerator reaches the On temperature later than the temperature sensed by the evaporator sensor. 
     
     
         18 . The control method according to  claim 14 , wherein controlling the On/Off operations of the cooling system and the fan based on the sensed temperature of the evaporator and the sensed interior temperature of the refrigerator includes starting a cooling operation after waiting until the temperature sensed by the evaporator sensor reaches an On temperature of the temperature sensor if the interior temperature of the refrigerator reaches the On temperature faster than the temperature sensed by the evaporator sensor. 
     
     
         19 . The control method according to  claim 14 , wherein controlling the On/Off operations of the cooling system and the fan includes repeating a cycle consisting of a natural defrosting period from Off time of the cooling system to Off time of the fan and a rest period from Off time of the fan to time when the cooling system and the fan are again turned on. 
     
     
         20 . The refrigerator according to  claim 13 , wherein the refrigerator does not include a heater to heat the lower region of the storage compartment.