Method for controlling refrigerator

Abstract

A method for controlling a refrigerator includes driving a compressor, operating a switching valve to allow a refrigerant to flow into at least one main expansion valve, opening a cool air passage connecting a refrigerating compartment to a main evaporator to cool the refrigerating compartment, operating the switching valve to switching a flow direction of the refrigerant into at least one deep-freezing expansion valve when a temperature of the refrigerating compartment is cooled to a temperature lower than a set temperature, thereby cooling the deep-freezing storage chamber, and operating the heater.

What is claimed is: 
     
         1 . A method for controlling a refrigerator comprising: a compressor to compress a refrigerant; a condenser connected to an outlet-side of the compressor to condense the refrigerant; a switching valve connected to an outlet-side of the condenser; an expansion member connected parallel to an outlet-side of the switching valve, the expansion member comprising at least one main expansion valve and at least one deep-freezing expansion valve; a main evaporator to cool air supplied to at least one of a refrigerating compartment and a freezing compartment, the main evaporator being connected to an outlet-side of the at least one main expansion valve; a deep-freezing evaporator to cool air supplied into a deep-freezing storage chamber which is maintained at a temperature lower than that of the freezing compartment, the deep-freezing evaporator being connected to the outlet-side of the at least one deep-freezing expansion valve; and a heater contacting the at least one deep-freezing expansion valve, the method comprising:
 driving the compressor;   operating the switching valve to allow the refrigerant to flow into the at least one main expansion valve;   opening a cool air passage connecting the refrigerating compartment to the main evaporator to cool the refrigerating compartment;   operating the switching valve to switching a flow direction of the refrigerant into the at least one deep-freezing expansion valve when a temperature of the refrigerating compartment is cooled to a temperature lower than a set temperature, thereby cooling the deep-freezing storage chamber; and   operating the heater.   
     
     
         2 . The method of  claim 1 , wherein the operation of the heater is controlled so that an evaporation temperature (pressure) of the refrigerant passing through the at least one deep-freezing expansion valve is lowered to a temperature lower than that of the refrigerant passing through the at least one main expansion valve. 
     
     
         3 . The method of  claim 2 , wherein, when the cooling of the deep-freezing storage chamber starts, the compressor is driven at an output greater than that in the cooling of the refrigerating compartment. 
     
     
         4 . The method of  claim 3 , wherein, when the cooling of the deep-freezing storage chamber starts, the compressor is driven at a maximum output. 
     
     
         5 . The method of  claim 4 , further comprising:
 driving a deep-freezing chamber fan when the compressor is changed in operation condition, a set time elapses from a time point at which the switching valve is switched, or the temperature of the deep-freezing evaporator is lower than the set temperature.   
     
     
         6 . The method of  claim 5 , wherein the heater is operated when the set time elapses from one of the time point at which the switching valve is switched, the time point at which the compressor operation condition is changed, and the time point at which the deep-freezing chamber fan is operated. 
     
     
         7 . The method of  claim 6 , wherein the compressor and the deep-freezing chamber fan operation are stopped when the deep-freezing storage chamber is cooled to a temperature lower than the set temperature. 
     
     
         8 . The method of  claim 7 , wherein the switching valve is switched to a position at which the refrigerant is introduced into the at least one main expansion valve when the compressor operation is stopped.