Refrigerator

Abstract

The present disclosure relates to a refrigerator. The refrigerator according to an embodiment of the present disclosure comprises: an evaporator; a defrost heater; a temperature sensor to sense ambient temperature around the evaporator; and a controller to control the defrost heater, wherein the controller is configured to: perform a defrost operation mode in a case of reaching a defrosting operation start time point; perform, based on the defrost operation mode, a continuous operation mode in which the defrost heater is continuously turned on, and a pulse operation mode in which the defrost heater is repeatedly turned on and off; and perform the continuous operation mode again after performing the pulse operation mode. Accordingly, defrosting efficiency may be improved, and power consumption may be reduced.

What is claimed is: 
     
         1 . A refrigerator, comprising:
 an evaporator configured to perform heat exchange;   a defrost heater configured to operate to remove frost formed on the evaporator;   a temperature sensor configured to detect an ambient temperature of the evaporator; and   a controller configured to control the defrost heater,   wherein, in response to a defrosting operation start time point arriving, the controller is configured to perform a defrost operation mode,   perform a continuous operation mode, in which the defrost heater is continuously turned on, and a pulse operation mode, in which the defrost heater is repeatedly turned on and off based on the defrost operation mode, and   perform the continuous operation mode again after performing the pulse operation mode.   
     
     
         2 . The refrigerator of  claim 1 , wherein, in response to a return condition to the continuous operation mode of the defrost heater arriving while performing the pulse operation mode, the controller is configured to perform the continuous operation mode. 
     
     
         3 . The refrigerator of  claim 1 , wherein, in response to a value related to the temperature detected by the temperature sensor doing not reach a reference value while performing the pulse operation mode, in response to the temperature detected by the temperature sensor being below a reference temperature while performing the pulse operation mode, in response to a change rate of the temperature detected by the temperature sensor being less than or equal to a change rate of the reference temperature while performing the pulse operation mode, or in response to the temperature detected by the temperature sensor doing not reach a target temperature within a certain time while performing the pulse operation mode, the controller is configured to perform the continuous operation mode. 
     
     
         4 . The refrigerator of  claim 1 , wherein, in response to a sum of an ON time of the defrost heater while performing the pulse operation mode being greater than or equal to a reference level, in response to a sum of the number of opening times the defrost heater while performing the pulse operation mode being greater than or equal to the reference number of opening times, or in response to the sum of the ON time of the defrost heater while performing the pulse operation mode being greater than a sum of a continuous ON time of the defrost heater in the continuous operation mode, the controller is configured to perform the continuous operation mode. 
     
     
         5 . The refrigerator of  claim 1 , wherein, in response to a door open period being greater than or equal to an allowable period while performing the pulse operation mode, the controller is configured to perform the continuous operation mode. 
     
     
         6 . The refrigerator of  claim 1 , wherein, in response to humidity in the refrigerator being greater than or equal to reference humidity while performing the pulse operation mode, the controller is configured to perform the continuous operation mode. 
     
     
         7 . The refrigerator of  claim 1 , wherein, in response to a defrosting operation start time point arriving while performing a normal cooling operation mode, the controller is configured to perform the defrost operation mode including a pre-defrost cooling mode, a heater operation mode, and a post-defrost cooling mode, and
 perform the continuous operation mode of the defrost heater, and the pulse operation mode, in which the defrost heater is repeatedly turned on and off, based on the heater operation mode.   
     
     
         8 . The refrigerator of  claim 1 , wherein the controller is configured to continuously turn on the defrost heater based on the continuous operation mode,
 in response to a change rate of the ambient temperature of the evaporator detected by the temperature sensor being greater than or equal to a first reference value in an ON state of the defrost heater, enter the pulse operation mode and turn off the defrost heater, and   in response to the change rate of the ambient temperature of the evaporator being less than or equal to a second reference value less than the first reference value in a state in which the defrost heater is turned off during the pulse operation mode, turn on the defrost heater.   
     
     
         9 . The refrigerator of  claim 1 , wherein the controller is configured to continuously turn on the defrost heater based on the continuous operation mode, and
 repeatedly turn on and off the defrost heater for the change rate of the ambient temperature of the evaporator to be between the first reference value and the second reference value based on the pulse operation mode.   
     
     
         10 . The refrigerator of  claim 1 , wherein as the number of opening times of the cooling compartment door increases, the controller is configured to decrease a duration of the defrost operation mode. 
     
     
         11 . The refrigerator of  claim 1 , wherein the controller is configured to control a peak temperature arrival time point of the evaporator in response to the continuous operation mode and the pulse operation mode being performed to be later than the peak temperature arrival time point of the evaporator in response to the defrost heater being only continuously turned on in the defrost operation mode. 
     
     
         12 . The refrigerator of  claim 1 , wherein the controller is configured to control a size of a second section related to temperature versus time between a phase-change temperature and the defrost end temperature in response to the continuous operation mode and the pulse operation mode being performed in the defrost operation mode to be greater than a size of a first section related to temperature versus time between the phase-change temperature and the defrost end temperatures only in response to the defrost heater being continuously turned on in the defrost operation mode. 
     
     
         13 . The refrigerator of  claim 1 , wherein the controller is configured to control an effective defrost in response to the continuous operation mode and the pulse operation mode being performed in the defrost operation mode to be greater than the effective defrost in response to the defrost heater being only continuously turned on in the defrost operation mode. 
     
     
         14 . The refrigerator of  claim 1 , wherein the controller is configured to control a heater OFF time point in response to the continuous operation mode and the pulse operation mode being performed in the defrost operation mode to be later than the heater OFF time point in response to the defrost heater being only continuously turned on in the defrost operation mode. 
     
     
         15 . The refrigerator of  claim 1 , wherein, in response to a defrosting operation start time point arriving, the controller is configured to perform the defrost operation mode including a pre-defrost cooling mode, a heater operation mode, and a post-defrost cooling mode,
 in response to the temperature detected by the temperature sensor reaching the first temperature within a first period during the continuous operation mode in which the defrost heater is continuously turned on based on the heater operation mode, perform the pulse operation mode in which the defrost heater is repeatedly turned on and off, and   in response to the period during which the temperature detected by the temperature sensor reaching the first temperature while performing the continuous operation mode is greater than or equal to a second period greater than the first period, continuously perform the continuous operation mode.   
     
     
         16 . A refrigerator, comprising:
 an evaporator configured to perform heat exchange;   a defrost heater configured to operate to remove frost formed on the evaporator;   a temperature sensor configured to detect an ambient temperature of the evaporator; and   a controller configured to control the defrost heater,   wherein, in response to a defrosting operation start time point arriving, the controller is configured to perform a defrost operation mode,   perform a continuous operation mode, in which the defrost heater is continuously turned on, and a pulse operation mode, in which the defrost heater is repeatedly turned on and off based on the defrost operation mode, and   in response to a return condition to the continuous operation mode of the defrost heater arriving while performing the pulse operation mode, perform the continuous operation mode again.   
     
     
         17 . A refrigerator, comprising:
 an evaporator configured to perform heat exchange;   a defrost heater configured to operate to remove frost formed on the evaporator;   a temperature sensor configured to detect an ambient temperature of the evaporator; and   a controller configured to control the defrost heater,   wherein, in response to a defrosting operation start time point arriving, the controller is configured to perform the defrost operation mode including a pre-defrost cooling mode, a heater operation mode, and a post-defrost cooling mode,   in response to the temperature detected by the temperature sensor reaching the first temperature within a first period during the continuous operation mode in which the defrost heater is continuously turned on based on the heater operation mode, perform the pulse operation mode in which the defrost heater is repeatedly turned on and off, and   in response to the period during which the temperature detected by the temperature sensor reaching the first temperature while performing the continuous operation mode is greater than or equal to a second period greater than the first period, continuously perform the continuous operation mode.   
     
     
         18 . The refrigerator of  claim 17 , wherein, in response to the temperature detected by the temperature sensor reaching a second temperature higher than the first temperature after arriving at the first temperature between the first period and the second period while performing the continuous operation mode, the controller is configured to perform the pulse operation mode after the defrost heater is turned off. 
     
     
         19 . The refrigerator of  claim 18 , wherein the controller is configured to control an OFF period of the defrost heater before performing the pulse operation mode in response to the temperature detected by the temperature sensor reaching a second temperature higher than the first temperature between the first period and the second period to be greater than the OFF period of the defrost heater before performing the pulse operation mode in response to the temperature detected by the temperature sensor reaching the first temperature within the first period. 
     
     
         20 . The refrigerator of  claim 17 , wherein, in response to the temperature detected by the temperature sensor reaching the first temperature between the first period and the second period while performing the continuous operation mode, the controller is configured to perform the pulse operation mode after the defrost heater is turned off.