Control method of a refrigerator

Abstract

An embodiment according to the present invention is to provide a control method of a refrigerator that can operate a compressor before a start of a defrost operation and during a predetermined time to supply a high-temperature hot gas to an evaporator. With the control method of the refrigerator according to the embodiments of the refrigerator, the compressor is driven immediately before the defrost operation and the blower fan cooling the compressor stops, such that the high-temperature hot gas can be supplied to the evaporator, thereby increasing the defrost efficiency.

1 . A control method of a refrigerator, comprising:
 a normal operation step that is repeatedly turned-on/off by a compressor and performs a normal freezing operation;   an operation step before defrost that is selectively performed according to whether a start signal of a defrost operation is input and controls an turn-on/off operation of a blower fan cooling the compressor according to whether a temperature of the open air reaches a first setting temperature before the start signal of the defrost operation is input; and   a defrost operation step that controls to bypass a refrigerant discharged from the compressor to an evaporator by the input of the start signal of the defrost operation and selectively performs a high-temperature defrost operation or a low-temperature defrost operation according to whether the open temperature reaches a second setting temperature,   wherein it returns to the normal operation step after the defrost operation step is ended.   
     
     
         2 . The control method of a refrigerator according to  claim 1 , wherein the start signal of the defrost operation is periodically input according to the set time interval and the operation step before defrost is continuously performed until the start signal of the defrost operation is input. 
     
     
         3 . The control method of a refrigerator according to  claim 1 , wherein the operation step before defrost controls the turn-on/off of the blower fan according to whether the setting time before the input of the start signal of the defrost operation passes. 
     
     
         4 . The control method of a refrigerator according to  claim 3 , wherein when the setting time does not pass, the blower fan is turned-on, when the setting time passes, the blower fan is controlled to be turned-on/off according to whether the temperature of the open air reaches the first setting temperature. 
     
     
         5 . The control method of a refrigerator according to  claim 4 , wherein when the temperature of the open air is higher than the first setting temperature, the blower fan is controlled to be turned-on, and when the temperature of the open air is lower than the first setting temperature, the blower fan is controlled to be turned-off and the compressor is operated. 
     
     
         6 . The control method of a refrigerator according to  claim 1 , wherein the defrost operation step performs the high-temperature defrost operation when the temperature of the open air is higher than the second setting temperature and performs the low-temperature defrost operation when the temperature of the open air is lower than the second setting temperature. 
     
     
         7 . The control method of a refrigerator according to  claim 6 , wherein the rotation speed of the compressor at the high-temperature defrost operation is formed to be higher than the rotation speed of the compressor at the low-temperature defrost operation. 
     
     
         8 . The control method of a refrigerator according to  claim 1 , wherein the high-temperature defrost operation and the low-temperature defrost operation are selectively performed according to whether the temperature of the evaporator is higher than the third setting temperature. 
     
     
         9 . The control method of a refrigerator according to  claim 1 , wherein at the high-temperature defrost operation, the rotation speed of the compressor is maintained for the predetermined time after being linearly increased from the initial rotation speed to the highest rotation speed and then linearly reduced. 
     
     
         10 . The control method of a refrigerator according to  claim 1 , wherein at the low-temperature defrost operation, the rotation speed of the compressor is maintained until the defrost operation is ended after being linearly increased from the initial rotation speed to the highest rotation speed. 
     
     
         11 . A control method of a refrigerator, comprising:
 a normal operation step that generates cool air by a refrigerant circulating a compressor, a condenser, an expander, and an evaporator;   a defrost operation step that periodically operates according to an input of a start signal of the defrost operation and selectively performs the defrost of the evaporator according to whether the temperature of the evaporator reaches a third setting temperature; and   an operation step before defrost that is performed before the defrost operation step and when a setting time does not pass before the input of the start signal of the defrost operation, turns-on a blower fan cooling the compressor and when the setting time passes, controls the turn-on/off of the blower fan according to whether the temperature of the open air is higher than the first setting temperature.   
     
     
         12 . The control method of a refrigerator according to  claim 11 , wherein the defrost of the evaporator is simultaneously performed with an operation of a defrost heater and the hot-gas defrost that supplies the refrigerant from the discharge side of the compressor to the inlet side of the evaporator. 
     
     
         13 . The control method of a refrigerator according to  claim 12 , wherein the compressor at the hot-gas defrost is decelerated at the highest rotation speed at the instant that the refrigerant pressure sucked into the inlet side of the evaporator exceeds a setting pressure. 
     
     
         14 . The control method of a refrigerator according to  claim 11 , wherein at the defrost operation, the low-temperature defrost operation that operates the compressor at low speed and the high-temperature defrost operation that operates the compressor at higher speed than the compressor of the low-temperature defrost operation are selectively performed according to whether the temperature of the open air is higher than a second setting temperature. 
     
     
         15 . The control method of a refrigerator according to  claim 14 , wherein during the high-temperature defrost operation, the compressor is sequentially operated at:
 a first period that is increased from an initial rotation speed to a highest rotation speed;   a second period that maintains the highest rotation speed during a predetermined period after reaching the highest rotation speed; and   a third period that is reduced from the highest rotation speed to the lowest rotation speed; and   a fourth period that maintains the rotation speed until the defrost operation is ended after reaching the lowest rotation speed.   
     
     
         16 . The control method of a refrigerator according to  claim 15 , wherein during the low-temperature defrost operation, the compressor includes:
 a first period where is increased from an initial rotation speed to a highest rotation speed; and   a second period that maintains the highest rotation speed during a predetermined period after reaching the highest rotation speed,   when the temperature of the evaporator reaches the third setting temperature, the voltage supplied to the compressor is turned-off.