US20230160625A1 - Refrigerator - Google Patents

Refrigerator Download PDF

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Publication number
US20230160625A1
US20230160625A1 US17/923,485 US202117923485A US2023160625A1 US 20230160625 A1 US20230160625 A1 US 20230160625A1 US 202117923485 A US202117923485 A US 202117923485A US 2023160625 A1 US2023160625 A1 US 2023160625A1
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US
United States
Prior art keywords
operation mode
defrost
temperature
heater
controller
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
US17/923,485
Inventor
Youngseung SONG
Kyongbae PARK
Yunsu Cho
Sangbok Choi
Namsoo Cho
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
LG Electronics Inc
Original Assignee
LG Electronics Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from KR1020200054354A external-priority patent/KR20210136306A/en
Priority claimed from KR1020200054351A external-priority patent/KR20210136303A/en
Application filed by LG Electronics Inc filed Critical LG Electronics Inc
Assigned to LG ELECTRONICS INC. reassignment LG ELECTRONICS INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: Choi, Sangbok, CHO, NAMSOO, CHO, YUNSU, PARK, KYONGBAE, SONG, Youngseung
Publication of US20230160625A1 publication Critical patent/US20230160625A1/en
Pending legal-status Critical Current

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Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25DREFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
    • F25D21/00Defrosting; Preventing frosting; Removing condensed or defrost water
    • F25D21/06Removing frost
    • F25D21/08Removing frost by electric heating
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25DREFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
    • F25D21/00Defrosting; Preventing frosting; Removing condensed or defrost water
    • F25D21/002Defroster control
    • F25D21/006Defroster control with electronic control circuits
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25DREFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
    • F25D2321/00Details or arrangements for defrosting; Preventing frosting; Removing condensed or defrost water, not provided for in other groups of this subclass
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25DREFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
    • F25D2700/00Means for sensing or measuring; Sensors therefor
    • F25D2700/10Sensors measuring the temperature of the evaporator

Definitions

  • the present disclosure relates to a refrigerator, and more particularly, to a refrigerator capable of improving defrosting efficiency and power consumption.
  • a refrigerator temperature is reduced using a compressor and an evaporator.
  • a freezer compartment in the refrigerator is maintained at a temperature of approximately ⁇ 18° C.
  • Prior Document 1 Korean Patent Application Laid-Open No. 10-2001-0026176 (hereinafter, referred to as Prior Document 1) relates to a method for controlling a defrost heater of a refrigerator, in which the defrost heater is turned on when a certain time for defrosting arrives, and turned off after the lapse of a certain period of time.
  • U.S. Pat. No. 6,694,754 (hereinafter, referred to as Prior Document 2) relates to a refrigerator having a pulse-based defrost heater, disclosing that the On and off time of a defrost heater is determined based on time.
  • Prior Document 3 Korean Patent Application Laid-Open No. 10-2016-0053502 (hereinafter, referred to as Prior Document 3) relates to a defrosting device, a refrigerator having the same, and a control method of the defrosting device, in which the On and off time of a defrost heater determined based on time or time and temperature.
  • An aspect of the present disclosure provides a refrigerator capable of improving defrosting efficiency and power consumption.
  • Another aspect of the present disclosure provides a refrigerator capable of performing a continuous operation mode again after a pulse operation mode of a defrost heater.
  • a refrigerator includes: 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 is configured to perform the continuous operation mode again after performing the pulse operation mode.
  • the controller may be configured to perform the continuous operation mode.
  • the controller may be configured to perform the continuous operation mode.
  • the controller may be configured to perform the continuous operation mode.
  • the controller may be configured to perform the continuous operation mode.
  • the controller may be configured to perform the continuous operation mode.
  • the controller may be configured to perform the continuous operation mode.
  • the controller may be configured to perform the continuous operation mode.
  • the controller may be configured to perform the continuous operation mode.
  • the controller may be configured to perform the continuous operation mode.
  • the controller may be configured to perform the continuous operation mode.
  • the controller may be 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.
  • the controller may be 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.
  • the controller may be 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.
  • the controller may be configured to, as the number of opening times of the cooling compartment door increases, decrease a duration of the defrost operation mode.
  • the controller may be 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.
  • the controller may be 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.
  • the controller may be 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.
  • the controller may be 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.
  • the controller may be 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.
  • 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
  • a refrigerator in another aspect, includes: 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.
  • a refrigerator in further another aspect, includes: 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.
  • the controller may be configured to perform the pulse operation mode after the defrost heater is turned off.
  • the controller may be 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.
  • the controller may be configured to perform the pulse operation mode after the defrost heater is turned off.
  • the controller may be 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 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.
  • the controller may be configured to, as the change rate of the temperature detected by the temperature sensor decreases while performing the continuous operation mode, increase a delay of a start time point of the pulse operation mode.
  • the controller may be configured to, as the change rate of the temperature detected by the temperature sensor decreases while performing the continuous operation mode, increase the duration of the pulse operation mode.
  • a refrigerator includes: 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 is configured to perform the continuous operation mode again after performing the pulse operation mode. Accordingly, the present disclosure can improve a defrosting efficiency and reduce power consumption. In particular, since the defrosting is performed according to the amount of frost of the actual evaporator, it is possible to improve defrosting efficiency and power consumption.
  • the controller may be configured to perform the continuous operation mode. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • the controller may be configured to perform the continuous operation mode. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • the controller may be configured to perform the continuous operation mode. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • the controller may be configured to perform the continuous operation mode. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • the controller may be configured to perform the continuous operation mode. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • the controller may be configured to perform the continuous operation mode. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • the controller may be configured to perform the continuous operation mode. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • the controller may be configured to perform the continuous operation mode. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • the controller may be configured to perform the continuous operation mode. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • the controller may be configured to perform the continuous operation mode. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • the controller may be configured to perform the defrost operation mode including a pre-defrost cooling mode, a heater operation mode, and a post-defrost cooling mode, and control the continuous operation mode of the defrost heater and the pulse operation mode, in which the defrost heater is repeatedly turned on and off, to be performed based on the heater operation mode. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • the controller may be configured to continuously turn on the defrost heater based on the continuous operation mode, and enter the pulse operation mode and turn off the defrost heater in response to the change rate of the ambient temperature of the evaporator detected by the temperature sensor being greater than or equal to the first reference value in the ON state of the defrost heater, and turn on the defrost heater in response to the change rate of the ambient temperature of the evaporator being less than or equal to the second reference value less than the first reference value in the state in which the defrost heater is turned off during the pulse operation mode. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • the controller may be configured to turn off the defrost heater based on the heater pulse operation end condition. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • the controller may be 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 temperature around the evaporator being between the first reference value and the second reference value based on the pulse operation mode. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • the controller may be configured to perform the pulse operation mode. Accordingly, the present disclosure can improve a defrosting efficiency and reduce power consumption.
  • the controller may be configured to perform the pulse operation mode. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • the controller may be configured to perform the pulse operation mode. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • the controller may be configured to perform the pulse operation mode based on the temperature change rate of the temperature detected by the temperature sensor. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • the controller may be configured to operate the heater with power inversely proportional to the temperature change rate of the temperature detected by the sensor during the pulse operation mode. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • the controller may be configured to, as the number of opening times of the cooling compartment door increases, decrease the duration of the defrost operation mode. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • the controller may be configured to control a peak temperature arrival point of the evaporator in response to the continuous operation mode and the pulse operation mode being performed in the defrost operation mode to be later than a peak temperature arrival point of the evaporator in response to the defrost heater being only continuously turned on in the defrost operation mode. Accordingly, defrosting efficiency may be improved and power consumption may be improved.
  • the controller may be configured to control a size of a second section related to a temperature versus time between a phase-change temperature and a 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 a temperature versus time between the phase-change temperature and the defrost end temperature in response to the defrost heater being only continuously turned on in the defrost operation mode. Accordingly, defrosting efficiency may be improved and power consumption may be improved.
  • the controller may be 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 an effective defrost in response to the defrost heater being only continuously turned on in the defrost operation mode. Accordingly, defrosting efficiency may be improved and power consumption may be improved.
  • the controller may be 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 a heater OFF time point in response to the defrost heater being only continuously turned on in the defrost operation mode. Accordingly, defrosting efficiency may be improved and power consumption may be improved.
  • the controller may be 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. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • 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
  • a refrigerator includes: 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. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption. In particular, since the defrosting is performed according to the amount of frost of the actual evaporator, it is possible to improve defrosting efficiency and power consumption.
  • a refrigerator includes: 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.
  • the controller may be configured to perform the pulse operation mode after the defrost heater is turned off. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • the controller may be 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. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • the controller may be configured to perform the pulse operation mode after the defrost heater is turned off. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • the controller may be 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 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. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • the controller may be configured to, as the change rate of the temperature detected by the temperature sensor decreases while performing the continuous operation mode, increase a delay of a start time point of the pulse operation mode. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • the controller may be configured to, as the change rate of the temperature detected by the temperature sensor decreases while performing the continuous operation mode, increase the duration of the pulse operation mode. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • FIG. 1 is a perspective view illustrating a refrigerator according to an embodiment of the present disclosure
  • FIG. 2 is a perspective view of a door of the refrigerator of FIG. 1 ;
  • FIG. 3 is a view schematically illustrating a configuration of the refrigerator of FIG. 1 ;
  • FIG. 4 is a block diagram schematically illustrating the inside of the refrigerator shown in FIG. 1 ;
  • FIG. 5 A is a perspective view illustrating an example of an evaporator associated with the present disclosure
  • FIG. 5 B is a diagram referenced in the description of FIG. 5 A ;
  • FIG. 6 is a flowchart illustrating a method of operating a refrigerator according to an embodiment of the present disclosure
  • FIGS. 7 A to 13 are diagrams referenced in the description of FIG. 6 ;
  • FIG. 14 is a flowchart illustrating a method of operating a defrost heater according to another embodiment of the present disclosure
  • FIGS. 15 A to 15 D are diagrams referenced in the description of FIG. 14 ;
  • FIG. 16 is a flowchart illustrating a defrosting method according to another embodiment of the present disclosure.
  • FIGS. 17 A to 17 D are diagrams referenced in the description of FIG. 16 .
  • FIG. 1 is a perspective view illustrating a refrigerator according to an embodiment of the present disclosure.
  • a refrigerator 100 forms a rough outer shape by a case 110 having an internal space divided, although not shown, into a freezer compartment and a refrigerating compartment, a freezer compartment door 120 that shields the freezer compartment, and a refrigerator door 140 to shield the refrigerating compartment.
  • the front surface of the freezer compartment door 120 and the refrigerating compartment door 140 is further provided with a door handle 121 protruding forward, so that a user easily grips and rotates the freezer compartment door 120 and the refrigerating compartment door 140 .
  • the front surface of the refrigerating compartment door 140 may be further provided with a home bar 180 which is a convenient means for allowing a user to take out a storage such as a beverage contained therein without opening the refrigerating compartment door 140 .
  • the front surface of the freezer compartment door 120 may be provided with a dispenser 160 which is a convenient means for allowing the user to easily take out ice or drinking water without opening the freezer compartment door 120 , and a control panel 210 for controlling the driving operation of the refrigerator 100 and displaying the state of the refrigerator 100 being operated on a screen may be further provided in an upper side of the dispenser 160 .
  • the dispenser 160 is disposed in the front surface of the freezer compartment door 120 , but is not limited thereto, and may be disposed in the front surface of the refrigerating compartment door 140 .
  • the control panel 210 may include an input device 220 formed of a plurality of buttons, and a display device 230 for displaying a control screen, an operation state, and the like.
  • the display device 230 displays information such as a control screen, an operation state, a temperature inside the refrigerator, and the like.
  • the display device 230 may display the set temperature of the freezer compartment and the set temperature of the refrigerating compartment.
  • the display device 230 may be implemented in various ways, such as a liquid crystal display (LCD), a light emitting diode (LED), an organic light emitting diode (OLED), and the like.
  • the display device 230 may be implemented as a touch screen capable of serving as the input device 220 .
  • the input device 220 may include a plurality of operation buttons.
  • the input device 220 may include a freezer compartment temperature setting button (not shown) for setting the freezer compartment temperature, and a refrigerating compartment temperature setting button (not shown) for setting the refrigerating compartment temperature.
  • the input device 220 may be implemented as a touch screen that may also function as the display device 230 .
  • the refrigerator according to an embodiment of the present disclosure is not limited to a double door type shown in the drawing, but may be a one door type, a sliding door type, a curtain door type, and the like regardless of its type.
  • FIG. 2 is a perspective view of a door of the refrigerator of FIG. 1 .
  • a freezer compartment 155 is disposed inside the freezer compartment door 120
  • a refrigerating compartment 157 is disposed inside the refrigerating compartment door 140 .
  • FIG. 3 is a view schematically illustrating a configuration of the refrigerator of FIG. 1 .
  • the refrigerator 100 may include a compressor 112 , a condenser 116 for condensing a refrigerant compressed by the compressor 112 , a freezer compartment evaporator 122 which is supplied with the refrigerant condensed in the condenser 116 to evaporate, and is disposed in a freezer compartment (not shown), and a freezer compartment expansion valve 132 for expanding the refrigerant supplied to the freezer compartment evaporator 122 .
  • the refrigerator 100 may further include a refrigerating compartment evaporator (not shown) disposed in a refrigerating compartment (not shown), a three-way valve (not shown) for supplying the refrigerant condensed in the condenser 116 to the refrigerating compartment evaporator (not shown) or the freezer compartment evaporator 122 , and a refrigerating compartment expansion valve (not shown) for expanding the refrigerant supplied to the refrigerating compartment evaporator (not shown).
  • a refrigerating compartment evaporator (not shown) disposed in a refrigerating compartment (not shown)
  • a three-way valve for supplying the refrigerant condensed in the condenser 116 to the refrigerating compartment evaporator (not shown) or the freezer compartment evaporator 122
  • a refrigerating compartment expansion valve not shown
  • the refrigerator 100 may further include a gas-liquid separator (not shown) which separates the refrigerant passed through the evaporator 122 into a liquid and a gas.
  • a gas-liquid separator (not shown) which separates the refrigerant passed through the evaporator 122 into a liquid and a gas.
  • the refrigerator 100 may further include a refrigerating compartment fan (not shown) and a freezer compartment fan 144 that suck cold air that passed through the freezer compartment evaporator 122 and blow the sucked cold air into a refrigerating compartment (not shown) and a freezer compartment (not shown) respectively.
  • the refrigerator 100 may further include a compressor driver 113 for driving the compressor 112 , and a refrigerating compartment fan driver (not shown) and a freezer compartment fan driver 145 for driving the refrigerating compartment fan (not shown) and the freezer compartment 144 .
  • a damper (not shown) may be installed between the refrigerating compartment and the freezer compartment, and a fan (not shown) may forcibly blow the cold air generated in one evaporator to be supplied to the freezer compartment and the refrigerating compartment.
  • FIG. 4 is a block diagram schematically illustrating the inside of the refrigerator shown in FIG. 1 .
  • the refrigerator of FIG. 4 includes a compressor 112 , a machine room fan 115 , the freezer compartment fan 144 , a controller 310 , a heater 330 , a temperature sensor 320 , and a memory 240 , and an evaporator 122 .
  • the refrigerator may further include a compressor driver 113 , a machine room fan driver 117 , a freezer compartment fan driver 145 , a heater driver 332 , a display device 230 , and an input device 220 .
  • the compressor 112 , the machine room fan 115 , and the freezer compartment fan 144 are described with reference to
  • the input device 220 includes a plurality of operation buttons, and transmits a signal for an input freezer compartment set temperature or refrigerating compartment set temperature to the controller 310 .
  • the display device 230 may display an operation state of the refrigerator. Meanwhile, the display device 230 is operable under the control of a display controller (not shown).
  • the memory 240 may store data necessary for operating the refrigerator.
  • the memory 240 may store power consumption information for each of the plurality of power consumption devices. In addition, the memory 240 may output corresponding power consumption information to the controller 310 based on the operation of each power consumption device in the refrigerator.
  • the temperature sensor 320 detects a temperature in the refrigerator and transmits a signal for the detected temperature to the controller 310 .
  • the temperature sensor 320 detects the refrigerating compartment temperature and the freezer compartment temperature respectively.
  • the temperature of each chamber in the refrigerating compartment or each chamber in the freezer compartment may be detected.
  • the controller may control the compressor driver 113 , the fan driver 117 or 145 , the heater driver 332 to eventually control the compressor 112 , the fan 115 or 144 , and the heater 330 .
  • the fan driver may be the machine room fan driver 117 or the freezer compartment fan driver 145 .
  • the controller 310 may output a corresponding speed command value signal to the compressor driver 113 or the fan driver 117 or 145 respectively.
  • the compressor driver 113 and the freezer compartment fan driver 145 described above are provided with a compressor motor (not shown) and a freezer compartment fan motor (not shown) respectively, and each motor (not shown) may be operated at a target rotational speed under the control of the controller 310 .
  • the machine room fan driver 117 includes a machine room fan motor (not shown), and the machine room fan motor (not shown) may be operated at a target rotational speed under the control of the controller 310 .
  • each motor may be controlled by a switching operation in an inverter (not shown) or may be controlled at a constant speed by using an AC power source intactly.
  • each motor may be any one of an induction motor, a Blush less DC (BLDC) motor, a synchronous reluctance motor (synRM) motor, and the like.
  • the controller 310 may control the overall operation of the refrigerator 100 , in addition to the operation control of the compressor 112 and the fan 115 or 144 .
  • the controller 310 may control the overall operation of the refrigerant cycle based on the set temperature from the input device 220 .
  • the controller 310 may further control a three-way valve (not shown), a refrigerating compartment expansion valve (not shown), and a freezer compartment expansion valve 132 , in addition to the compressor driver 113 , the refrigerating compartment fan driver 143 , and the freezer compartment fan driver 145 .
  • the operation of the condenser 116 may also be controlled.
  • the controller 310 may control the operation of the display device 230 .
  • the cold air heat-exchanged in the evaporator 122 may be supplied to the freezer compartment or the refrigerating compartment by a fan or a damper (not shown).
  • the heater 330 may be a freezer compartment defrost heater.
  • the freezer compartment defrost heater 330 may operate to remove frost attached to the freezer compartment evaporator 122 .
  • the heater driver 332 may control the operation of the heater 330 .
  • the controller 310 may control the heater driver 332 .
  • the heater 330 may include a freezer compartment defrost heater and a refrigerating compartment defrost heater.
  • the freezer compartment defrost heater 330 may operates to remove frost attached to the freezer compartment evaporator 122
  • the refrigerating compartment defrost heater (not shown) may operate to remove frost attached to the refrigerating compartment evaporator.
  • the heater driver 332 may control the operations of the freezer compartment defrost heater 330 and the refrigerating compartment defrost heater.
  • FIG. 5 A is a perspective view illustrating an example of an evaporator related to the present disclosure
  • FIG. 5 B is a diagram referenced in the description of FIG. 5 A .
  • the evaporator 122 in the refrigerator 100 may be a freezer compartment evaporator as described above with reference to FIG. 2 .
  • a sensor mounter 400 including a temperature sensor 320 may be attached to the evaporator 122 in the refrigerator 100 .
  • a sensor mounter 400 is attached to an upper cooling pipe of the evaporator 122 in the refrigerator 100 .
  • the evaporator 122 includes a cooling pipe 131 extending from one side of the accumulator 134 and a support 133 supporting the cooling pipe 131 .
  • the cooling pipe 131 may be repeatedly bent in a zigzag manner to form multiple rows and may be filled with a refrigerant.
  • the defrost heater 330 for defrosting may be disposed in the vicinity of the cooling pipe 131 of the evaporator 122 .
  • the defrost heater 330 is disposed in the vicinity of the cooling pipe 131 in a lower region of the evaporator 122 .
  • frost ICE is formed from a lower region of the evaporator 122 and grows in an upward direction
  • the defrost heater 330 may be disposed in the vicinity of the cooling pipe 131 in the lower region of the evaporator 122 .
  • the defrost heater 330 may be disposed in a shape surrounding the cooling pipe 131 of the lower region of the evaporator 122 .
  • FIG. 5 B illustrates frost ICE is attached to the evaporator 122 .
  • frost ICE is attached to a central portion and a lower portion of the evaporator 122 .
  • frost ICE is formed on the defrost heater 330 to cover the defrost heater 330 .
  • frost ICE is removed from the lower region of the evaporator 122 and may be gradually removed in the direction of the central region.
  • FIG. 6 is a flowchart illustrating a method of operating a refrigerator according to an embodiment of the present disclosure.
  • the controller 310 of the refrigerator 100 determines whether a defrosting operation start time point for defrosting arrives (S 610 ).
  • the controller 310 of the refrigerator 100 may determine whether a defrosting operation start time point arrives while performing a normal cooling operation mode Pga.
  • the defrosting operation start time point may vary according to a defrost cycle.
  • the amount of cold air supplied in the normal cooling operation mode increases, and accordingly, a rate at which frost is formed on the evaporator 122 may increase.
  • the controller 310 of the refrigerator 100 may control such that a defrost cycle is shortened.
  • the controller 310 of the refrigerator 100 may control the defrosting operation start time point to be shortened.
  • the controller 310 of the refrigerator 100 may end the normal cooling operation mode, control to perform a defrost operation mode PDF, and control the defrost heater 330 to be continuously turned on based on a heater operation mode PddT in the defrost operation mode PDF (S 615 ).
  • the controller 310 of the refrigerator 100 may be configured to perform a pulse operation mode in which the defrost heater 330 is repeatedly turned on and off by a heater pulse after the defrost heater 330 is continuously turned on (S 620 ).
  • the controller 310 of the refrigerator 100 may be configured to perform the defrost operation mode PDF including a pre-defrost cooling mode Pbd, a heater operation mode PddT, and a post-defrost cooling mode pbf.
  • the controller may be configured to perform a continuous operation mode Pona in which the defrost heater 330 is continuously turned on and a pulse operation mode Ponb in which the defrost heater 330 is repeatedly turned on and off.
  • the controller 310 controls the defrost heater 330 to be continuously turned on based on the continuous operation mode Pona, and in the ON state of the defrost heater 330 , when a change rate of an ambient temperature of the evaporator 122 detected by the temperature sensor 320 is equal to or greater than a first reference value ref 1 , the controller 310 may enter the pulse operation mode Ponb to control the defrost heater 330 to be turned off. Accordingly, defrosting efficiency and power consumption may be improved.
  • the controller 310 of the refrigerator 100 may control the defrost heater 330 to be turned on and off based on a change rate of the temperature detected by the temperature sensor 320 when the pulse operation mode Ponb is performed.
  • the controller 310 of the refrigerator 100 may control the defrost heater 330 to be turned off, and if the change rate of the temperature detected by the temperature sensor 320 is less than or equal to a second reference value ref 2 less than the first reference value ref 1 , the controller 310 may control the defrost heater 330 to be turned on. Accordingly, since defrosting may be performed based on a change rate ⁇ T of the temperature, defrosting efficiency and power consumption may be improved.
  • the controller 310 of the refrigerator 100 determines whether a pulse operation mode end time point arrives (S 630 ), and if pulse operation mode end time point arrives, the controller 310 turns off the defrost heater 330 (S 640 ).
  • the pulse operation mode end time point may be a time point at which the temperature detected by the temperature sensor 320 falls below a phase-change temperature Trf 1 .
  • the pulse operation mode end time point may be an end time point of the defrosting operation or an end time point of the heater operation mode.
  • the continuous operation mode Pona in which the defrost heater 330 is continuously turned on and the pulse operation mode in which the defrost heater 330 is repeatedly turned on and off are controlled to be performed based on the change rate of the temperature detected by the temperature sensor 320 , defrosting efficiency and power consumption may be improved by performing defrosting based on the change rate ⁇ T of the temperature.
  • defrosting efficiency and power consumption may be improved.
  • FIGS. 7 A to 13 are diagrams referenced in the description of FIG. 6 .
  • FIG. 7 A is a diagram illustrating a defrost heater HT and a switching element RL for driving a defrost heater when one evaporator and one defrost heater are used in the refrigerator 100 .
  • the freezer compartment defrost heater HT may operate to remove frost attached to the freezer compartment evaporator 122 .
  • the switching element RL in the heater driver 332 may control the operation of the defrost heater HT.
  • the switching element RL may be a relay element.
  • the continuous operation mode Pona in which the defrost heater HT is continuously turned on may be performed, and when the switching element RL is switched On and off, the pulse operation mode Ponb in which the defrost heater HT is repeatedly turned on and off may be performed.
  • FIG. 7 B is a diagram illustrating defrost heaters HTa and HTb and switching elements RLa and Rlb for driving the defrost heaters when two evaporators and two defrost heaters are used in the refrigerator 100 .
  • a first switching element RLa in the heater driver 332 may control the operation of the first defrost heater HTa.
  • the first switching element RLa may be a relay element.
  • the continuous operation mode Pona in which the first defrost heater HTa is continuously turned on may be performed, and when the first switching element RLa performs On and off switching, the pulse operation mode Ponb in which the first defrost heater HTa is repeatedly turned on and off may be performed.
  • a second switching element RLb in the heater driver 332 may control the operation of the second defrost heater HTb.
  • the second switching element RLb may be a relay element.
  • the continuous operation mode Ponb in which the second defrost heater HTb is continuously turned on may be performed, and when the second switching element RLb performs On and off switching, the pulse operation mode Ponb in which the second defrost heater HTb is repeatedly turned on and off may be performed.
  • On and off timings of the first switching element RLa and the second switching element RLb may be different from each other. Accordingly, it is possible to perform the defrosting of the freezer compartment evaporator and the defrosting of the refrigerating compartment evaporator, separately.
  • FIG. 8 A is a diagram illustrating an example of a pulse waveform indicating an operation of one defrost heater of FIG. 7 A .
  • the horizontal axis of the pulse waveform Psh may represent time and the vertical axis may represent a level.
  • the controller 310 of the refrigerator 100 may end the normal cooling operation mode Pga and control to perform the defrost operation mode pdf.
  • the defrost operation mode pdf may include a pre-defrost cooling mode Pbd between Toa and Ta, a heater operation mode PddT between Ta and Td, and a post-defrost cooling mode pbf between Td and Te.
  • the defrost heater 330 is turned off in the normal cooling operation mode Pga and the normal cooling operation mode Pgb.
  • the defrost heater 330 may be turned off in the pre-defrost cooling mode Pbd and the post-defrost cooling mode pbf of the defrost operation mode PDF.
  • the defrost heater 330 may be continuously turned on in the continuous operation mode Pona of the heater operation mode PddT, and may be repeatedly turned on and off in the pulse operation mode Ponb of the heater operation mode PddT.
  • the continuous operation mode Pona may be performed between Ta and Tb, and the pulse operation mode Ponb may be performed between Tb and Tc.
  • the continuous operation mode Pona and the pulse operation mode Ponb are used in combination. Accordingly, defrosting efficiency and power consumption may be improved.
  • FIG. 8 B is a diagram illustrating an example of a pulse waveform indicating an operation of two defrost heaters of FIG. 7 B .
  • FIG. 8 B shows a pulse waveform Psha indicating an operation of the freezer compartment defrost heater
  • (b) of FIG. 8 B shows a pulse waveform Pshb indicating an operation of the refrigerating compartment defrost heater.
  • the pulse waveform Psha of (a) of FIG. 8 B may be the same as the pulse waveform Psh of FIG. 8 A .
  • an operating section of the refrigerating compartment defrost heater may be less than an operating section of the freezer compartment defrost heater.
  • a period of continuously turning on in the continuous operation mode Pona in the heater operation mode PddT may be less than a period of the pulse waveform Psha of (a) of FIG. 8 B .
  • an ON/OFF repetition period of the pulse operation mode Ponb in the heater operation mode PddT may be less than the pulse waveform Psha of (a) of FIG. 8 B .
  • FIG. 9 is a diagram illustrating an example of cooling power supply and a defrost heater operation in the defrost operation mode pdf of FIG. 8 A .
  • the defrost operation mode pdf may include a pre-defrost cooling mode Pbd between To and Ta, a heater operation mode PddT between Ta and Td, and a post-defrost cooling mode pbf between Td and Te.
  • a level of supplied cooling power may be an R level, and during a period T 1 to T 2 , a level of cooling power may be an F level greater than the R level.
  • the cooling power supply may be stopped.
  • a level of supplied cooling power may be the R level.
  • cooling power supply for compensating for the stoppage of cooling power supply during the heater operation mode PddT is performed.
  • the cooling power supply may be performed by a compressor, a thermoelectric element, or the like, and in the drawings, it is illustrated that the cooling power supply is performed by an operation of the compressor.
  • the compressor operates, and during a period T 2 to T 3 in which cooling power is not supplied, the compressor is turned off.
  • the refrigerating compartment fan may operate and the freezer compartment fan may be turned off.
  • the refrigerating compartment fan may be turned off and the freezer compartment fan may be operated.
  • the defrost heater 330 should be maintained in an OFF state.
  • the defrost heater 330 may operate during the period of Ta to Tc in the period of Ta to Td of the heater operation mode PddT.
  • the continuous operation mode Pona may be performed during the period of Ta and Tb of the heater operation mode PddT period, and the heater operation mode PddT may be performed during the Tb and Tc periods.
  • the defrost heater 330 may be turned off from Tc, which is an end time point of the continuous operation mode Pona, to Td.
  • the compressor and the refrigerating compartment fan may be turned off.
  • the freezer compartment fan may be turned off.
  • the freezer compartment fan is turned off from Tc, which is the end time point of the continuous operation mode Pona, to Td.
  • the post-defrost cooling mode Pbf is performed.
  • a level of the supplied cooling power may be an R+F level, and the largest level of cooling power may be supplied.
  • a level of the supplied cooling power may be F level, and the cooling power supply may be stopped during the period T 6 to Te.
  • the largest level of cooling power supply may be performed according to the stopping of the cooling power supply during the heater operation mode PddT.
  • the compressor operates, and the compressor is turned off during the period of T 6 to Te in which cooling power is not supplied.
  • the refrigerating compartment fan and the freezer compartment fan may be turned off together.
  • the refrigerating compartment fan may be turned off and the freezer compartment fan may be operated.
  • the level of power consumption in the heater operation mode PddT in FIG. 9 may be greater than the level of power consumption of the R+F level cooling power.
  • FIG. 10 is a diagram illustrating temperature change waveforms of an evaporator in response to the defrost heater being operated only in the continuous operation mode and in response to the continuous operation mode and the pulse operation mode being mixed.
  • CVa represents a temperature change waveform in response to the defrost heater being operated only in the continuous operation mode
  • CVb represents a temperature change waveform in response to the defrost heater being operated by mixing the continuous operation mode and the pulse operation mode.
  • the defrost heater 330 is continuously turned on, and may be turned off at a time point Tx, as shown in (b) of FIG. 10 .
  • the defrost heater 330 operates during the Pohm period, as shown in (c) of FIG. 10 .
  • the continuous operation mode is performed, and the pulse operation mode is performed during a Pofn period from Tpa to Tpb.
  • Trf 1 represents a phase-change temperature, and may be, for example, 0° C.
  • Trf 2 represents a defrost end temperature, for example, may be 5° C.
  • Trf 1 and Trf 2 may indicate a defrosting region in which defrosting is actually performed, and a region exceeding Trf 2 may indicate an overheating region in which excessive defrosting is performed.
  • a size of the overheating region is reduced and a size of the defrosting region is increased.
  • the continuous operation mode and the pulse operation mode of the defrost heater 300 are mixed in order to reduce the size of the overheating region and increase the size of the defrosting region.
  • the controller 310 may be configured to control a peak temperature arrival point Qd of the evaporator 122 when the continuous operation mode Pona and the pulse operation mode Ponb are performed in the defrost operation mode PDF to be later than a peak temperature arrival point Qc of the evaporator 122 when the defrost heater 330 is only continuously turned on in the defrost operation mode PDF. Accordingly, it is possible to improve the defrosting efficiency and power consumption when the continuous operation mode Pona and the pulse operation mode Ponb are performed.
  • the controller 310 may be configured to control a size of a second section Arbb related to a temperature versus time between a phase-change temperature Trf 1 and a defrost end temperature Trf 2 in response to the continuous operation mode and the pulse operation mode being performed in the defrost operation mode PDF to be greater than a size of a first section Arab related to a temperature versus time between the phase-change temperature Trf 1 and the defrost end temperature Trf 2 in response to the defrost heater being only continuously turned on in the defrost operation mode PDF. Accordingly, it is possible to improve the defrosting efficiency and power consumption when the continuous operation mode Pona and the pulse operation mode Ponb are performed.
  • the controller 310 may be configured to control an effective defrost when the continuous operation mode Pona and the pulse operation mode Ponb are performed in the defrost operation mode PDF to be greater than an effective defrost when the defrost heater 330 is only continuously turned on in the defrost operation mode PDF. Accordingly, it is possible to improve the defrosting efficiency and power consumption when the continuous operation mode Pona and the pulse operation mode Ponb are performed.
  • the controller 310 may be configured to control a heater OFF time point Tpb when the continuous operation mode Pona and the pulse operation mode Ponb are performed in the defrost operation mode PDF to be later than a heater OFF time point Tx when the defrost heater 330 is only continuously turned on in the defrost operation mode PDF. Accordingly, it is possible to improve the defrosting efficiency and power consumption when the continuous operation mode Pona and the pulse operation mode Ponb are performed.
  • the controller 310 may be configured to control a period Tpb-Qd between the heater OFF time point Tpb and a peak temperature arrival time Qd of the evaporator 122 when the continuous operation mode Pona and the pulse operation mode Ponb are performed in the defrost operation mode PDF to be greater than a period Tx-Qc between the heater OFF time point and the peak temperature arrival time Qc of the evaporator 122 when the defrost heater 330 is only continuously turned on in the defrost operation mode PDF. Accordingly, it is possible to improve the defrosting efficiency and power consumption when the continuous operation mode Pona and the pulse operation mode Ponb are performed.
  • the controller 310 may be configured to control a period Tpb-Qh during which a temperature maintains above the phase-change temperature Trf 1 when the continuous operation mode Pona and the pulse operation mode Ponb are performed in the defrost operation mode PDF to be greater than a period Tx-Qg during which a temperature maintains above the phase-change temperature Trf 1 when the defrost heater 330 is only continuously turned on in the defrost operation mode PDF. Accordingly, it is possible to improve the defrosting efficiency and power consumption when the continuous operation mode Pona and the pulse operation mode Ponb are performed
  • the controller 310 may be configured to control a period Tpb-Qh between the heater OFF time point Tpb to a time point at which a temperature falls below a phase-change temperature Trf 1 when the continuous operation mode Pona and the pulse operation mode Ponb are performed in the defrost operation mode PDF to be less than a period Tx-Qg between the heater OFF time point Tx to a time point Qg at which the temperature falls below the phase-change temperature Trf 1 when the defrost heater 330 is only continuously turned on in the defrost operation mode PDF. Accordingly, it is possible to improve the defrosting efficiency and power consumption when the continuous operation mode Pona and the pulse operation mode Ponb are performed.
  • the controller 310 may be configured to control a size of an overheat temperature region Arba equal to higher than the defrosting end temperature Trf 2 when the continuous operation mode Pona and the pulse operation mode Ponb are performed in the defrost operation mode PDF to be less than an overheat temperature region Araa equal to higher than the defrosting end temperature Trf 2 when the defrost heater 330 is only continuously turned on in the defrost operation mode PDF. Accordingly, it is possible to improve the defrosting efficiency and power consumption when the continuous operation mode Pona and the pulse operation mode Ponb are performed.
  • (d) shows a cooling power supply waveform COa in the case of only continuously turning on the defrost heater 330 and a cooling power supply waveform COb in the case of performing a continuous operation mode Pona and a pulse operation mode Ponb.
  • the controller 310 may be configured to control a cooling power supply time point Tcb according to a normal cooling operation mode Pga when the continuous operation mode Pona and the pulse operation mode Ponb are performed in the defrost operation mode PDF to be later than a cooling power supply time point Tca according to the normal cooling operation mode Pga when the defrost heater 330 is only continuously turned on in the defrost operation mode PDF.
  • FIG. 11 is a diagram illustrating an operating method in a pulse operation mode according to an embodiment of the present disclosure.
  • the controller 310 controls the defrost heater 330 to be turned on based on the heater operation mode, in particular, based on the continuous operation mode (S 1115 ).
  • the controller 310 calculates a change rate ⁇ T of a temperature detected by the temperature sensor 320 during the operation of the defrost heater 330 , and determines whether the change rate ⁇ T of the temperature is equal to or greater than a first reference value ref 1 (S 1120 ).
  • the controller 310 may control the defrost heater 330 to continuously operate.
  • the controller 310 may temporarily turn off the defrost heater 330 (S 1125 ).
  • the controller 310 calculates the change rate ⁇ T of the temperature detected by the temperature sensor 320 after the defrost heater 330 is temporarily turned off, and determine whether the change rate ⁇ T of the temperature is less than or equal to a second reference value ref 2 (S 1128 ).
  • the controller 310 is configured to turn on the defrost heater. That is, the controller 310 controls to perform step S 1115 .
  • step S 1128 after the defrost heater 330 is temporarily turned off, when the change rate ⁇ T of the temperature exceeds the second reference value ref 2 , the controller 310 determines a pulse operation mode end condition is met.
  • the controller 310 ends the pulse operation mode and controls the heater to be turned off (S 1140 ).
  • the pulse operation mode end condition may correspond to the pulse operation mode time point.
  • the pulse operation mode end time point may be a time at which the temperature detected by the temperature sensor 320 falls below the phase-change temperature Trf 1 .
  • the pulse operation mode end time point may be an end time point of the defrosting operation or an end time point of the heater operation mode.
  • the controller 310 controls to perform the defrost operation mode PDF and controls to perform the continuous operation mode Pona in which the defrost heater 330 is continuously turned on and the pulse operation mode Ponb in which the defrost heater 330 is repeatedly turned on and off based on the defrost operation mode PDF, and in response to performing the pulse operation mode Ponb, the controller controls the defrost heater 330 to be turned on and off based on the change rate ⁇ T of the temperature detected by the temperature sensor 320 . Accordingly, since defrosting may be performed based on the change rate ⁇ T of the temperature, it is possible to improve defrost efficiency and power consumption.
  • the controller 310 may be configured to perform the continuous operation mode Pona or the pulse operation mode Ponb based on the change rate ⁇ T of the temperature detected by the temperature sensor 320 . Accordingly, it is possible to improve the defrosting efficiency and power consumption.
  • the controller 310 may be configured to operate the heater with power inversely proportional to the change rate ⁇ T of the temperature detected by the sensor during the pulse operation mode Ponb. Accordingly, it is possible to improve the defrosting efficiency and power consumption.
  • the controller 310 may be configured to decrease a period of performing the defrost operation mode PDF as the number of opening times the cooling compartment door increases. Accordingly, it is possible to improve the defrosting efficiency and power consumption.
  • FIG. 12 A is a diagram showing a temperature waveform of the evaporator when there is a large amount of frost formation.
  • CVma represents a temperature change waveform in response to the defrost heater being operated only in the continuous operation mode
  • CVmb represents a temperature change waveform in response to the defrost heater being operated by mixing the continuous operation mode and the pulse operation mode.
  • the defrost heater 330 may be continuously turned on, and may be turned off at a time point Tmg, as shown in (b) of FIG. 12 A .
  • the defrost heater 330 is continuously turned on during a Tma period and turned off during Tma and Tmb, during Tmc and Tmd, during Tme and Tmf, and during Tmg and Tmh, and the defrost heater 330 is turned on during Tmb and Tmc, during Tmd and Tme, during Tmf and Tmg, and during Tmh and Tmi.
  • the defrost heater 330 operates in the pulse operation mode.
  • the controller 310 controls the defrost heater 330 to be continuously turned on based on the continuous operation mode Pona, and in the ON state of the defrost heater 330 , when the change rate ⁇ T of the ambient temperature of the evaporator 122 detected by the temperature sensor 320 is equal to or greater than the first reference value ref 1 , the controller 310 may enter the pulse operation mode Ponb and control the defroster heater 330 to be turned off. Accordingly, it is possible to improve the defrosting efficiency and power consumption.
  • the controller 310 may control the defrost heater 330 to be turned on. Accordingly, it is possible to improve the defrosting efficiency and power consumption.
  • the controller 310 may control the defrost heater 330 may to be turned on. Accordingly, it is possible to improve the defrosting efficiency and power consumption.
  • the controller 310 may control the defrost heater 330 to be continuously turned on based on the continuous operation mode Pona, and based on the pulse operation mode Ponb, the controller 310 may repeatedly turned on and off the defrost heater 320 so that the change rate ⁇ T of the temperature around the evaporator 122 may be between the first reference value ref 1 and the second reference value ref 2 . Accordingly, it is possible to improve the defrosting efficiency and power consumption.
  • FIG. 12 B is a diagram showing a temperature waveform of the evaporator when the amount of frost formation is less than that of FIG. 12 A .
  • CVna represents a temperature change waveform in response to the defrost heater being operated only in the continuous operation mode
  • CVnb represents a temperature change waveform in response to the defrost heater being operated by mixing the continuous operation mode and the pulse operation mode.
  • the defrost heater 330 may be continuously turned on and may be turned off at a time point Tng, as shown in (b) of FIG. 12 B .
  • the defrost heater 330 is continuously turned on during a period of Tna, and the defrost heater 330 is turned off during Tna and Tnb, during Tnc and Tnd, during Tne and Tnf, and during Tng and Tnh, and turned on during Tnb and Tnc, during Tnd and Tne, during Tnf and Tng, and during Tnh and Tni.
  • the defrost heater 330 operates in the pulse operation mode.
  • FIG. 13 is a view showing a region requiring cooling power supply and a region requiring defrosting according to temperatures of the refrigerating compartment and the freezer compartment.
  • the horizontal axis may indicate a temperature of the refrigerating compartment
  • the vertical axis may indicate a temperature of the freezer compartment.
  • a temperature is equal to or lower than a reference temperature of the freezer compartment refma, it may indicate that a freezing capacity is sufficient, and when the temperature is equal to or lower than a reference temperature of the refrigerating compartment refmb, it may indicate that cooling capacity of the refrigerating compartment is sufficient.
  • An Arma region in the drawing is a region in which freezing capacity of the freezer compartment and cooling capacity of the refrigerating compartment are sufficient, and may be a region requiring defrosting.
  • the controller 310 may be configured to perform the continuous operation mode and the pulse operation mode described above.
  • ON/OFF of the defrost heater 330 in the pulse operation mode may be controlled based on a temperature change rate around the evaporator 122 .
  • the Armb region in the drawing may be a region in which both cooling power of the freezer compartment and cooling power of the refrigerating compartment are insufficient, and may be a cooling power supply requiring region requiring cooling power supply.
  • the controller 310 may control supply of cooling power.
  • a compressor may be operated or a thermoelectric element may be operated to control supply of cooling power.
  • FIG. 14 is a flowchart illustrating a method of operating a defrost heater according to another embodiment of the present disclosure
  • FIGS. 15 A to 15 D are diagrams referenced in the description of FIG. 14 .
  • the controller 310 of the refrigerator 100 determines whether a defrosting operation start time point arrives for defrosting (S 610 ).
  • the controller 310 of the refrigerator 100 may determine whether a defrosting operation start time point arrives, while performing the normal cooling operation mode Pga.
  • the defrosting operation start time point may vary according to a defrost cycle.
  • the controller 310 of the refrigerator 100 may end the normal cooling operation mode and control to perform the defrost operation mode pdf.
  • the defrost operation mode PDF may include a pre-defrost cooling mode Pbd, a heater operation mode PddT, and a post-defrost cooling mode pbf.
  • the heater operation mode PddT may include a continuous operation mode Pona in which the defrost heater 330 is continuously turned on, and a pulse operation mode Ponb in which the defrost heater 330 is repeatedly turned on and off.
  • the controller 310 of the refrigerator 100 may control the defrost heater 330 to be continuously turned on based on the heater operation mode PddT in the defrost operation mode PDF (S 615 ).
  • the controller 310 may control the defrost heater 330 to be continuously turned on based on the continuous operation mode Pona in the heater operation mode PddT.
  • the controller 310 of the refrigerator 100 may control the pulse operation mode Ponb, in which the defrost heater 330 is repeatedly turned on and off, to be performed by a heater pulse after the defrost heater 330 is continuously turned on (S 620 ).
  • the controller 310 may determine whether the return condition to the continuous operation mode is satisfied (S 623 ), and if so, control the continuous operation mode to be performed again.
  • the controller 310 may control the pulse operation mode to end, and the continuous operation mode to be performed again.
  • the defrosting may be stably performed.
  • the controller 310 of the refrigerator 100 determines whether it is the pulse operation mode end time point (S 630 ), and if so, turns off the defrost heater 330 (S 640 ).
  • the pulse operation mode end point time may be a time point at which the temperature detected by the temperature sensor 320 falls below the phase change temperature Trf 1 .
  • the pulse operation mode end time point may be a defrost operation end time point or a heater operation mode end time point.
  • the controller 310 may control the continuous operation mode Ponc to be performed again after performing the pulse operation mode Ponb for stable defrosting. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption. In particular, since the defrosting is performed according to the amount of frost of the actual evaporator, it is possible to improve defrosting efficiency and power consumption.
  • the controller 310 may determine that the defrosting is not smooth, and control the continuous operation mode Ponc to be performed for quick defrosting. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • the controller 310 may control the continuous operation mode Ponc to be performed for quick defrosting. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • the controller 310 may determine that the defrosting is not smooth, and control the continuous operation mode Ponc to be performed for quick defrosting. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • the controller 310 may determine that the defrosting is not smooth, and control the continuous operation mode Ponc to be performed for quick defrosting. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • the controller 310 may determine that the defrosting is not smooth, and control the continuous operation mode Ponc to be performed for quick defrosting. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • the controller 310 may determine that the defrosting is not smooth, and control the continuous operation mode Ponc to be performed for quick defrosting. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • the controller 310 may determine that the defrosting is not smooth, and control the continuous operation mode Ponc to be performed for quick defrosting. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • the controller 310 may determine that the defrosting is not smooth, and control the continuous operation mode Ponc to be performed for quick defrosting. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • the controller 310 may determine that the defrosting is not smooth, and control the continuous operation mode Ponc to be performed for quick defrosting. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • FIG. 15 A is a diagram illustrating an example of a pulse waveform indicating an operation of a defrost heater according to an embodiment of the present disclosure.
  • a horizontal axis of a pulse waveform Pshm may indicate time, and a vertical axis may indicate a level.
  • the controller 310 of the refrigerator 100 may control the normal cooling operation mode Pga to end and the defrost operation mode PDF to be performed.
  • the defrost operation mode PDF may include the pre-defrost cooling mode Pbd between Toa and Ta, the heater operation mode PddT between Ta and Td, and the post-defrost cooling mode pbf between Td and Te.
  • the defrost heater 330 is turned off in the normal cooling operation mode Pga and the normal cooling operation mode Pgb.
  • the defrost heater 330 may be turned off in the pre-defrost cooling mode Pbd and the post-defrost cooling mode pbf of the defrost operation mode PDF.
  • the defrost heater 330 may be continuously turned on in the continuous operation mode Pona in the heater operation mode PddT, may repeat the turn on and off in the pulse operation mode Ponb in the heater operation mode PddT, and may be continuously turned on in the continuous operation mode Ponc in the heater operation mode PddT.
  • the controller 310 may control the continuous operation mode Ponc to be further performed.
  • the continuous operation mode Pona may be performed between Ta and Tb, and the pulse operation mode Ponb may be performed between Tb and Tc.
  • An additional continuous operation mode Ponc may be performed between Tcm and Td.
  • the period during which the additional continuous operation mode Ponc is performed is Mz.
  • FIG. 15 B is a diagram illustrating another example of a pulse waveform indicating an operation of a defrost heater according to an embodiment of the present disclosure.
  • a pulse waveform Pshn of FIG. 15 B is similar to the pulse waveform Pshm of FIG. 15 A , but the additional continuous operation mode Ponc is different in that it is performed between Tcm and Tcn.
  • My which is the duration of the additional continuous operation mode Ponc, is less than Mz of FIG. 15 A .
  • the controller 310 may vary the period during which the continuous operation mode Ponc is performed based on the difference between the value related to the temperature detected by the temperature sensor 320 and the reference value. For example, as the difference decreases, it is possible to control the period during which the continuous operation mode Ponc is performed to decrease. By this additional continuous operation mode Ponc, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • the controller 310 may vary the period during which the continuous operation mode Ponc is performed based on the difference between the temperature detected by the temperature sensor 320 and the reference temperature while performing the pulse operation mode Ponb. For example, as the difference decreases, it is possible to control the period during which the continuous operation mode Ponc is performed to decrease.
  • the controller 310 may vary the period during which the continuous operation mode Ponc is performed based on the difference between the change rate ⁇ T of the temperature detected by the temperature sensor 320 and the change rate ⁇ T of the reference temperature while performing the pulse operation mode Ponb. For example, as the difference decreases, it is possible to control the period during which the continuous operation mode Ponc is performed to decrease.
  • the controller 310 may vary the period during which the continuous operation mode Ponc is performed based on the difference between the temperature detected by the temperature sensor 320 and the target temperature while performing the pulse operation mode Ponb. For example, as the difference decreases, it is possible to control the period during which the continuous operation mode Ponc is performed to decrease.
  • the controller 310 may vary the period during which the continuous operation mode Ponc is performed based on the difference between the reference level and the sum Ma+Mb+ . . . Mn of the on time of the defrost heater 330 while performing the pulse operation mode Ponb. For example, as the difference decreases, it is possible to control the period during which the continuous operation mode Ponc is performed to decrease.
  • the controller 310 may vary the period during which the continuous operation mode Ponc is performed based on the difference between the reference number of opening times and the sum of the number of opening times of turn on of the defrost heater 330 while performing the pulse operation mode Ponb. For example, as the difference decreases, it is possible to control the period during which the continuous operation mode Ponc is performed to decrease.
  • the controller 310 may vary the period during which the continuous operation mode Ponc is performed based on the difference between the sum Mo of the continuous ON time and the sum Ma+Mb+ . . . Mn of the ON time of the defrost heater 330 while performing the pulse operation mode Ponb. For example, as the difference decreases, it is possible to control the period during which the continuous operation mode Ponc is performed to decrease.
  • the controller 310 may vary the period during which the continuous operation mode Ponc is performed based on the difference between the humidity in the refrigerator and the reference humidity while performing the pulse operation mode Ponb. For example, as the difference decreases, it is possible to control the period during which the continuous operation mode Ponc is performed to decrease.
  • FIG. 15 C is a diagram illustrating another example of a pulse waveform indicating an operation of a defrost heater according to an embodiment of the present disclosure.
  • a pulse waveform Psho of FIG. 15 c is similar to the pulse waveform (Pshm) of FIG. 15 A , but there is a difference in that after the pulse operation mode Ponb, an additional continuous operation mode Ponab and an additional pulse operation mode ponbb are further performed.
  • the duration of the additional continuous operation mode Ponab is preferably less than the duration of the continuous operation mode Pona.
  • the duration of the additional pulse operation mode ponbb is preferably less than the duration of the continuous operation mode Ponb. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • FIG. 16 is a flowchart illustrating a defrosting method according to another embodiment of the present disclosure
  • FIGS. 17 A to 17 D are diagrams referenced in the description of FIG. 16 .
  • the controller 310 of the refrigerator 100 determines whether a defrosting operation start time point arrives for defrosting (S 610 ).
  • the controller 310 of the refrigerator 100 may determine whether it is the defrosting operation start time point, while performing the normal cooling operation mode Pga.
  • the defrosting operation start time point may vary according to a defrost cycle.
  • the controller 310 of the refrigerator 100 may end the normal cooling operation mode and control the defrost operation mode PDF to be performed.
  • the defrost operation mode PDF may include a pre-defrost cooling mode Pbd, a heater operation mode PddT, and a post-defrost cooling mode pbf.
  • the heater operation mode (PddT) may include a continuous operation mode Pona in which the defrost heater 330 is continuously turned on, and a pulse operation mode Ponb in which the defrost heater 330 is repeatedly turned on and off.
  • the controller 310 of the refrigerator 100 may control the defrost heater 330 to be continuously turned on based on the continuous operation mode Pona in the heater operation mode PddT of the defrost operation mode PDF (S 615 ).
  • the controller 310 of the refrigerator 100 determines whether the temperature detected by the temperature sensor 320 reaches a first temperature Tm 1 within a first period Pm 1 while performing the continuous operation mode Pona (S 1616 ).
  • the controller 310 of the refrigerator 100 may control the pulse operation mode, in which the defrost heater 330 is repeatedly turned on and off, to be performed by the heater pulse after the defrost heater 330 is continuously turned on (S 1620 ).
  • FIG. 17 A illustrates an example of a temperature waveform Tcva around the evaporator 122
  • FIG. 17 A illustrates an example of an operating waveform Psh of the defrost heater 330 .
  • the continuous operation mode (Pona) is performed during the Pm 1 period between Ta and Tb.
  • the controller 310 of the refrigerator 100 may control the pulse operation mode Ponb to be performed after Tb.
  • the controller 310 of the refrigerator 100 may control the defrost heater 330 to be turned off during the period pf 1 and then the defrost heater 330 to be repeatedly turned on and off.
  • the controller 310 of the refrigerator 100 determines whether it is the pulse operation mode end time point (S 1630 ), and if so, turns off the defrost heater 330 (S 1640 ).
  • the pulse operation mode end point time may be a time point at which the temperature detected by the temperature sensor 320 falls below the phase change temperature Trf 1 .
  • the pulse operation mode end time point may be a defrost operation end time point or a heater operation mode end time point.
  • step S 1617 when the temperature detected by the temperature sensor 320 does not reach the first temperature Tm 1 within the first period Pm 1 while performing the continuous operation mode Pona, step S 1617 may be performed.
  • the controller 310 of the refrigerator 100 determines whether the first temperature Tm 1 arrival period is greater than or equal to the second period (S 1617 ).
  • the continuous operation mode Pona may be controlled to be continuously performed (S 1623 ).
  • FIG. 17 A illustrates another example of a temperature waveform Tcvb around the evaporator 122
  • FIG. 17 B illustrates another example of an operating waveform Pshb 1 of the defrost heater 330 .
  • the continuous operation mode Pona is performed during the period Pm 1 between Ta and Tb.
  • the controller 310 of the refrigerator 100 determines whether the first temperature Tm 1 arrival period is greater than or equal to the second period pm 2 .
  • the temperature detected by the temperature sensor 320 reaches the end time of the second period pm 2 .
  • the controller 310 of the refrigerator 100 may control the continuous operation mode Pona 1 to be performed during the periods Ta and Tc.
  • the controller 310 of the refrigerator 100 may control that, during the heater operation mode Pon, only the continuous operation mode Pona 1 is performed and the pulse operation mode (Ponb) is not performed. Accordingly, when the amount of frost formed on the evaporator 122 is large, it is possible to control to efficiently perform defrosting.
  • the controller 310 of the refrigerator 100 may control the continuous operation mode Pona 1 to be performed during a predetermined period after the period Tc.
  • step S 1622 may be performed again.
  • step S 1618 when the first temperature Tm 1 arrival period of the temperature detected by the temperature sensor 320 is not greater than or equal to the second period but is between the first period and the second period while performing the continuous operation mode Pona, step S 1618 may be performed
  • the controller 310 of the refrigerator 100 determines whether the temperature detected by the temperature sensor 320 reaches the second temperature Tm 2 between the first period and the second period while performing the continuous operation mode Pona (S 1618 ). If so, the defrost heater is turned off (S 1619 ), and the defrost heater may be controlled to be turned on and off based on the pulse operation mode (S 1621 ).
  • FIG. 17 C illustrates another example of a temperature waveform Tcvc around the evaporator 122
  • (b) of FIG. 17 C illustrates another example of an operating waveform Pshb 2 of the defrost heater 330 .
  • the continuous operation mode is performed during the period Pm 1 between Ta and Tb.
  • the controller 310 of the refrigerator 100 determines whether the first temperature Tm 1 arrival period is greater than or equal to the second period pm 2 or between the first period pm 1 and the second period pm 2 .
  • the temperature detected by the temperature sensor 320 reaches the first temperature Tm 1 in Tk between the first period pm 1 and the second period pm 2
  • the temperature detected by the temperature sensor 320 reaches the second temperature Tm 2 in Tm between the first period pm 1 and the second period pm 2 .
  • the controller 310 of the refrigerator 100 may be configured to perform the continuous operation mode until the time point Tm at which a temperature reaches the second temperature Tm 2
  • the pulse operation mode Ponb 2 may be controlled to be performed.
  • tit is preferable that the first OFF period psf 2 of the defrost heater 330 after the time point Tm is greater than the OFF period during the On and off of the pulse operation mode Ponb 2 .
  • the first OFF period psf 2 of the defrost heater 330 after the time point Tm when the pulse operation mode Ponb 2 is performed is greater than the first OFF period pof 1 of the defrost heater 330 after the time point Tb when the pulse operation mode Ponb of FIG. 17 A is performed. Accordingly, it is possible to protect the switching element RL of FIG. 7 A and the like.
  • the controller 310 may be configured to, as the change rate of the temperature detected by the temperature sensor 320 decreases while performing the continuous operation mode Pon, increase a delay of the start time point of the pulse operation mode Ponb.
  • the change rate of the temperature detected by the temperature sensor 320 is smaller, and accordingly, the start time point of the pulse operation mode is further delayed.
  • the change rate of the temperature detected by the temperature sensor 320 is smaller, and accordingly, the pulse operation mode may not start at all.
  • controller 310 may be configured to, as the change rate of the temperature detected by the temperature sensor decreases while performing the continuous operation mode Pona, increase the duration of the pulse operation mode Pona.
  • the change rate of the temperature detected by the temperature sensor 320 is smaller, and accordingly, the duration of the continuous operation mode is a period between Ta and Tm, and is greater than the period between Ta and Tb of FIG. 17 A .
  • the change rate of the temperature detected by the temperature sensor 320 is smaller, and accordingly, the duration of the continuous operation mode is a period between Ta and Tc, and is greater than the period between Ta and Tm of FIG. 17 B . Accordingly, it is possible to efficiently perform the defrosting.
  • the controller 310 may control the pulse operation mode Ponb to be performed after the defrost heater 310 is turned off without determining whether the second period Pm 2 arrives.
  • the controller 310 may be configured to control the OFF period of the defrost heater 310 before the pulse operation mode Ponb is performed when the temperature detected by the temperature sensor 320 reaches the first temperature Tm 1 between the first period Pm 1 and the second period Pm 2 to be greater than the OFF period of the defrost heater 310 before the pulse operation mode Ponb is performed when the temperature detected by the temperature sensor 320 reaches the first temperature Tm 1 within the first period Pm 1 . Accordingly, it is possible to efficiently perform the defrosting.
  • the configuration and the method of the embodiments as described above are not restrictively applied. Rather, all or some of the embodiments may be selectively combined with each other so that the embodiments may be variously modified.
  • the present disclosure can be applied to a refrigerator, and more particularly, can be applied to a refrigerator capable of improving defrosting efficiency and power consumption.

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.

Description

    BACKGROUND Field of the Disclosure
  • The present disclosure relates to a refrigerator, and more particularly, to a refrigerator capable of improving defrosting efficiency and power consumption.
  • Description of the Related Art
  • For long-term storage of foods in a refrigerator, a refrigerator temperature is reduced using a compressor and an evaporator. For example, a freezer compartment in the refrigerator is maintained at a temperature of approximately −18° C.
  • Meanwhile, in order to improve refrigerator performance, it is desirable to remove frost which may be on the evaporator when the evaporator operates.
  • Korean Patent Application Laid-Open No. 10-2001-0026176 (hereinafter, referred to as Prior Document 1) relates to a method for controlling a defrost heater of a refrigerator, in which the defrost heater is turned on when a certain time for defrosting arrives, and turned off after the lapse of a certain period of time.
  • However, according to Prior Document 1, since the ON time and the OFF time of the defrost heater are based on a certain time or a predetermined time, defrosting is not performed according to the actual amount of frost of an evaporator. That is, when the amount of frost is large, defrosting is not performed properly, or when the amount of frost is small, unnecessary defrosting is performed, thereby unnecessarily consuming power.
  • U.S. Pat. No. 6,694,754 (hereinafter, referred to as Prior Document 2) relates to a refrigerator having a pulse-based defrost heater, disclosing that the On and off time of a defrost heater is determined based on time.
  • According to Prior Document 2, since the ON time and the OFF time of the defrost heater are determined based on time, defrosting is not performed according to the actual amount of frost of an evaporator. That is, when the amount of frost is large, defrosting is not performed properly, or when the amount of frost is small, unnecessary defrosting is performed, thereby unnecessarily consuming power.
  • Korean Patent Application Laid-Open No. 10-2016-0053502 (hereinafter, referred to as Prior Document 3) relates to a defrosting device, a refrigerator having the same, and a control method of the defrosting device, in which the On and off time of a defrost heater determined based on time or time and temperature.
  • According to Prior Document 3, since the ON time and the OFF time of the defrost heater are determined based on time or time and temperature, defrosting is not performed according to the actual amount of frost of an evaporator. That is, when the amount of frost is large, defrosting is not performed properly, or when the amount of frost is small, unnecessary defrosting is performed, thereby unnecessarily consuming power.
  • SUMMARY
  • An aspect of the present disclosure provides a refrigerator capable of improving defrosting efficiency and power consumption.
  • Another aspect of the present disclosure provides a refrigerator capable of performing a continuous operation mode again after a pulse operation mode of a defrost heater.
  • In an aspect, a refrigerator includes: 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 is configured to perform the continuous operation mode again after performing the pulse operation mode.
  • In response to a return condition to the continuous operation mode of the defrost heater arriving while performing the pulse operation mode, the controller may be configured to perform the continuous operation mode.
  • 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, the controller may be configured to perform the continuous operation mode.
  • In response to the temperature detected by the temperature sensor being below a reference temperature while performing the pulse operation mode, the controller may be configured to perform the continuous 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, the controller may be configured to perform the continuous operation mode.
  • 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 may be configured to perform the continuous operation mode.
  • 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, the controller may be configured to perform the continuous operation mode.
  • 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, the controller may be configured to perform the continuous operation mode.
  • The sum of the ON time of the defrost heater while performing the pulse operation mode is greater than a sum of a continuous ON time of the defrost heater in the continuous operation mode, the controller may be configured to perform the continuous operation mode.
  • In response to a door open period being greater than or equal to an allowable period while performing the pulse operation mode, the controller may be configured to perform the continuous operation mode.
  • In response to humidity in the refrigerator being greater than or equal to reference humidity while performing the pulse operation mode, the controller may be configured to perform the continuous operation mode.
  • In response to a defrosting operation start time point arriving while performing a normal cooling operation mode, the controller may be 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.
  • The controller may be 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.
  • The controller may be 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.
  • The controller may be configured to, as the number of opening times of the cooling compartment door increases, decrease a duration of the defrost operation mode.
  • The controller may be 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.
  • The controller may be 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.
  • The controller may be 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.
  • The controller may be 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.
  • In response to a defrosting operation start time point arriving, the controller may be 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.
  • In another aspect, a refrigerator includes: 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.
  • In further another aspect, a refrigerator includes: 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.
  • 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 may be configured to perform the pulse operation mode after the defrost heater is turned off.
  • The controller may be 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.
  • 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 may be configured to perform the pulse operation mode after the defrost heater is turned off.
  • The controller may be 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 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.
  • The controller may be configured to, as the change rate of the temperature detected by the temperature sensor decreases while performing the continuous operation mode, increase a delay of a start time point of the pulse operation mode.
  • The controller may be configured to, as the change rate of the temperature detected by the temperature sensor decreases while performing the continuous operation mode, increase the duration of the pulse operation mode.
  • Effects of the Disclosure
  • A refrigerator according to an embodiment of the present disclosure includes: 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 is configured to perform the continuous operation mode again after performing the pulse operation mode. Accordingly, the present disclosure can improve a defrosting efficiency and reduce power consumption. In particular, since the defrosting is performed according to the amount of frost of the actual evaporator, it is possible to improve defrosting efficiency and power consumption.
  • In response to a return condition to the continuous operation mode of the defrost heater arriving while performing the pulse operation mode, the controller may be configured to perform the continuous operation mode. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • 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, the controller may be configured to perform the continuous operation mode. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • In response to the temperature detected by the temperature sensor being below a reference temperature while performing the pulse operation mode, the controller may be configured to perform the continuous operation mode. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • 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, the controller may be configured to perform the continuous operation mode. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • 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 may be configured to perform the continuous operation mode. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • 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, the controller may be configured to perform the continuous operation mode. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • 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, the controller may be configured to perform the continuous operation mode. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • The sum of the ON time of the defrost heater while performing the pulse operation mode is greater than a sum of a continuous ON time of the defrost heater in the continuous operation mode, the controller may be configured to perform the continuous operation mode. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • In response to a door open period being greater than or equal to an allowable period while performing the pulse operation mode, the controller may be configured to perform the continuous operation mode. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • In response to humidity in the refrigerator being greater than or equal to reference humidity while performing the pulse operation mode, the controller may be configured to perform the continuous operation mode. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • Meanwhile, in response to a defrosting operation start time point arriving while performing a normal cooling operation mode the controller may be configured to perform the defrost operation mode including a pre-defrost cooling mode, a heater operation mode, and a post-defrost cooling mode, and control the continuous operation mode of the defrost heater and the pulse operation mode, in which the defrost heater is repeatedly turned on and off, to be performed based on the heater operation mode. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • Meanwhile, the controller may be configured to continuously turn on the defrost heater based on the continuous operation mode, and enter the pulse operation mode and turn off the defrost heater in response to the change rate of the ambient temperature of the evaporator detected by the temperature sensor being greater than or equal to the first reference value in the ON state of the defrost heater, and turn on the defrost heater in response to the change rate of the ambient temperature of the evaporator being less than or equal to the second reference value less than the first reference value in the state in which the defrost heater is turned off during the pulse operation mode. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • Meanwhile, the controller may be configured to turn off the defrost heater based on the heater pulse operation end condition. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • Meanwhile, the controller may be 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 temperature around the evaporator being between the first reference value and the second reference value based on the pulse operation mode. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • Meanwhile, in response to the temperature detected by the temperature sensor being a predetermined temperature, the controller may be configured to perform the pulse operation mode. Accordingly, the present disclosure can improve a defrosting efficiency and reduce power consumption.
  • Meanwhile, in response to the temperature detected by the temperature sensor being a predetermined temperature, and an execution period of the continuous operation mode being longer than a predetermined period, the controller may be configured to perform the pulse operation mode. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • Meanwhile, when the execution period of the continuous operation mode is longer than a predetermined period, the controller may be configured to perform the pulse operation mode. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • Meanwhile, the controller may be configured to perform the pulse operation mode based on the temperature change rate of the temperature detected by the temperature sensor. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • Meanwhile, the controller may be configured to operate the heater with power inversely proportional to the temperature change rate of the temperature detected by the sensor during the pulse operation mode. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • Meanwhile, the controller may be configured to, as the number of opening times of the cooling compartment door increases, decrease the duration of the defrost operation mode. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • Meanwhile, the controller may be configured to control a peak temperature arrival point of the evaporator in response to the continuous operation mode and the pulse operation mode being performed in the defrost operation mode to be later than a peak temperature arrival point of the evaporator in response to the defrost heater being only continuously turned on in the defrost operation mode. Accordingly, defrosting efficiency may be improved and power consumption may be improved.
  • Meanwhile, the controller may be configured to control a size of a second section related to a temperature versus time between a phase-change temperature and a 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 a temperature versus time between the phase-change temperature and the defrost end temperature in response to the defrost heater being only continuously turned on in the defrost operation mode. Accordingly, defrosting efficiency may be improved and power consumption may be improved.
  • Meanwhile, the controller may be 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 an effective defrost in response to the defrost heater being only continuously turned on in the defrost operation mode. Accordingly, defrosting efficiency may be improved and power consumption may be improved.
  • Meanwhile, the controller may be 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 a heater OFF time point in response to the defrost heater being only continuously turned on in the defrost operation mode. Accordingly, defrosting efficiency may be improved and power consumption may be improved.
  • Meanwhile, in response to a defrosting operation start time point arriving, the controller may be 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. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • A refrigerator according to another embodiment of the present disclosure includes: 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. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption. In particular, since the defrosting is performed according to the amount of frost of the actual evaporator, it is possible to improve defrosting efficiency and power consumption.
  • A refrigerator according to another embodiment of the present disclosure includes: 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.
  • Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption. In particular, since the defrosting is performed according to the amount of frost of the actual evaporator, it is possible to improve defrosting efficiency and power consumption.
  • Meanwhile, 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 may be configured to perform the pulse operation mode after the defrost heater is turned off. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • Meanwhile, the controller may be 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. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • Meanwhile, 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 may be configured to perform the pulse operation mode after the defrost heater is turned off. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • The controller may be 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 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. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • Meanwhile, the controller may be configured to, as the change rate of the temperature detected by the temperature sensor decreases while performing the continuous operation mode, increase a delay of a start time point of the pulse operation mode. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • Meanwhile, the controller may be configured to, as the change rate of the temperature detected by the temperature sensor decreases while performing the continuous operation mode, increase the duration of the pulse operation mode. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. 1 is a perspective view illustrating a refrigerator according to an embodiment of the present disclosure;
  • FIG. 2 is a perspective view of a door of the refrigerator of FIG. 1 ;
  • FIG. 3 is a view schematically illustrating a configuration of the refrigerator of FIG. 1 ;
  • FIG. 4 is a block diagram schematically illustrating the inside of the refrigerator shown in FIG. 1 ;
  • FIG. 5A is a perspective view illustrating an example of an evaporator associated with the present disclosure;
  • FIG. 5B is a diagram referenced in the description of FIG. 5A;
  • FIG. 6 is a flowchart illustrating a method of operating a refrigerator according to an embodiment of the present disclosure;
  • FIGS. 7A to 13 are diagrams referenced in the description of FIG. 6 ;
  • FIG. 14 is a flowchart illustrating a method of operating a defrost heater according to another embodiment of the present disclosure;
  • FIGS. 15A to 15D are diagrams referenced in the description of FIG. 14 ;
  • FIG. 16 is a flowchart illustrating a defrosting method according to another embodiment of the present disclosure; and
  • FIGS. 17A to 17D are diagrams referenced in the description of FIG. 16 .
  • DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
  • Hereinafter, the present disclosure will be described in further detail with reference to the accompanying drawings.
  • The suffixes “module” and “unit” in elements used in description below are given only in consideration of ease in preparation of the specification and do not have specific meanings or functions. Therefore, the suffixes “module” and “unit” may be used interchangeably.
  • FIG. 1 is a perspective view illustrating a refrigerator according to an embodiment of the present disclosure.
  • Referring to the drawings, a refrigerator 100 according to an embodiment of the present disclosure forms a rough outer shape by a case 110 having an internal space divided, although not shown, into a freezer compartment and a refrigerating compartment, a freezer compartment door 120 that shields the freezer compartment, and a refrigerator door 140 to shield the refrigerating compartment.
  • In addition, the front surface of the freezer compartment door 120 and the refrigerating compartment door 140 is further provided with a door handle 121 protruding forward, so that a user easily grips and rotates the freezer compartment door 120 and the refrigerating compartment door 140.
  • Meanwhile, the front surface of the refrigerating compartment door 140 may be further provided with a home bar 180 which is a convenient means for allowing a user to take out a storage such as a beverage contained therein without opening the refrigerating compartment door 140.
  • In addition, the front surface of the freezer compartment door 120 may be provided with a dispenser 160 which is a convenient means for allowing the user to easily take out ice or drinking water without opening the freezer compartment door 120, and a control panel 210 for controlling the driving operation of the refrigerator 100 and displaying the state of the refrigerator 100 being operated on a screen may be further provided in an upper side of the dispenser 160.
  • Meanwhile, in the drawing, it is illustrated that the dispenser 160 is disposed in the front surface of the freezer compartment door 120, but is not limited thereto, and may be disposed in the front surface of the refrigerating compartment door 140.
  • The control panel 210 may include an input device 220 formed of a plurality of buttons, and a display device 230 for displaying a control screen, an operation state, and the like.
  • The display device 230 displays information such as a control screen, an operation state, a temperature inside the refrigerator, and the like. For example, the display device 230 may display the set temperature of the freezer compartment and the set temperature of the refrigerating compartment.
  • The display device 230 may be implemented in various ways, such as a liquid crystal display (LCD), a light emitting diode (LED), an organic light emitting diode (OLED), and the like. In addition, the display device 230 may be implemented as a touch screen capable of serving as the input device 220.
  • The input device 220 may include a plurality of operation buttons. For example, the input device 220 may include a freezer compartment temperature setting button (not shown) for setting the freezer compartment temperature, and a refrigerating compartment temperature setting button (not shown) for setting the refrigerating compartment temperature. Meanwhile, the input device 220 may be implemented as a touch screen that may also function as the display device 230.
  • Meanwhile, the refrigerator according to an embodiment of the present disclosure is not limited to a double door type shown in the drawing, but may be a one door type, a sliding door type, a curtain door type, and the like regardless of its type.
  • FIG. 2 is a perspective view of a door of the refrigerator of FIG. 1 .
  • Referring to the drawing, a freezer compartment 155 is disposed inside the freezer compartment door 120, and a refrigerating compartment 157 is disposed inside the refrigerating compartment door 140.
  • FIG. 3 is a view schematically illustrating a configuration of the refrigerator of FIG. 1 .
  • Referring to the drawing, the refrigerator 100 may include a compressor 112, a condenser 116 for condensing a refrigerant compressed by the compressor 112, a freezer compartment evaporator 122 which is supplied with the refrigerant condensed in the condenser 116 to evaporate, and is disposed in a freezer compartment (not shown), and a freezer compartment expansion valve 132 for expanding the refrigerant supplied to the freezer compartment evaporator 122.
  • Meanwhile, in the drawing, it illustrated that a single evaporator is used, but it is also possible to use respective evaporators may be used in the refrigerating compartment and the freezer compartment.
  • That is, the refrigerator 100 may further include a refrigerating compartment evaporator (not shown) disposed in a refrigerating compartment (not shown), a three-way valve (not shown) for supplying the refrigerant condensed in the condenser 116 to the refrigerating compartment evaporator (not shown) or the freezer compartment evaporator 122, and a refrigerating compartment expansion valve (not shown) for expanding the refrigerant supplied to the refrigerating compartment evaporator (not shown).
  • In addition, the refrigerator 100 may further include a gas-liquid separator (not shown) which separates the refrigerant passed through the evaporator 122 into a liquid and a gas.
  • In addition, the refrigerator 100 may further include a refrigerating compartment fan (not shown) and a freezer compartment fan 144 that suck cold air that passed through the freezer compartment evaporator 122 and blow the sucked cold air into a refrigerating compartment (not shown) and a freezer compartment (not shown) respectively.
  • In addition, the refrigerator 100 may further include a compressor driver 113 for driving the compressor 112, and a refrigerating compartment fan driver (not shown) and a freezer compartment fan driver 145 for driving the refrigerating compartment fan (not shown) and the freezer compartment 144.
  • Meanwhile, based on the drawing, since a common evaporator 122 is used for the refrigerating compartment and the freezer compartment, in this case, a damper (not shown) may be installed between the refrigerating compartment and the freezer compartment, and a fan (not shown) may forcibly blow the cold air generated in one evaporator to be supplied to the freezer compartment and the refrigerating compartment.
  • FIG. 4 is a block diagram schematically illustrating the inside of the refrigerator shown in FIG. 1 .
  • Referring to the drawings, the refrigerator of FIG. 4 includes a compressor 112, a machine room fan 115, the freezer compartment fan 144, a controller 310, a heater 330, a temperature sensor 320, and a memory 240, and an evaporator 122.
  • In addition, the refrigerator may further include a compressor driver 113, a machine room fan driver 117, a freezer compartment fan driver 145, a heater driver 332, a display device 230, and an input device 220.
  • The compressor 112, the machine room fan 115, and the freezer compartment fan 144 are described with reference to The input device 220 includes a plurality of operation buttons, and transmits a signal for an input freezer compartment set temperature or refrigerating compartment set temperature to the controller 310.
  • The display device 230 may display an operation state of the refrigerator. Meanwhile, the display device 230 is operable under the control of a display controller (not shown).
  • The memory 240 may store data necessary for operating the refrigerator.
  • For example, the memory 240 may store power consumption information for each of the plurality of power consumption devices. In addition, the memory 240 may output corresponding power consumption information to the controller 310 based on the operation of each power consumption device in the refrigerator.
  • The temperature sensor 320 detects a temperature in the refrigerator and transmits a signal for the detected temperature to the controller 310. Here, the temperature sensor 320 detects the refrigerating compartment temperature and the freezer compartment temperature respectively. In addition, the temperature of each chamber in the refrigerating compartment or each chamber in the freezer compartment may be detected.
  • In order to control an ON/OFF operation of the compressor 112, the fan 115 or 144, and the heater 330, as shown in the drawing, the controller may control the compressor driver 113, the fan driver 117 or 145, the heater driver 332 to eventually control the compressor 112, the fan 115 or 144, and the heater 330. Here, the fan driver may be the machine room fan driver 117 or the freezer compartment fan driver 145.
  • For example, the controller 310 may output a corresponding speed command value signal to the compressor driver 113 or the fan driver 117 or 145 respectively.
  • The compressor driver 113 and the freezer compartment fan driver 145 described above are provided with a compressor motor (not shown) and a freezer compartment fan motor (not shown) respectively, and each motor (not shown) may be operated at a target rotational speed under the control of the controller 310.
  • Meanwhile, the machine room fan driver 117 includes a machine room fan motor (not shown), and the machine room fan motor (not shown) may be operated at a target rotational speed under the control of the controller 310.
  • When such a motor is a three-phase motor, it may be controlled by a switching operation in an inverter (not shown) or may be controlled at a constant speed by using an AC power source intactly. Here, each motor (not shown) may be any one of an induction motor, a Blush less DC (BLDC) motor, a synchronous reluctance motor (synRM) motor, and the like.
  • Meanwhile, as described above, the controller 310 may control the overall operation of the refrigerator 100, in addition to the operation control of the compressor 112 and the fan 115 or 144.
  • For example, as described above, the controller 310 may control the overall operation of the refrigerant cycle based on the set temperature from the input device 220. For example, the controller 310 may further control a three-way valve (not shown), a refrigerating compartment expansion valve (not shown), and a freezer compartment expansion valve 132, in addition to the compressor driver 113, the refrigerating compartment fan driver 143, and the freezer compartment fan driver 145. In addition, the operation of the condenser 116 may also be controlled. In addition, the controller 310 may control the operation of the display device 230.
  • Meanwhile, the cold air heat-exchanged in the evaporator 122 may be supplied to the freezer compartment or the refrigerating compartment by a fan or a damper (not shown).
  • Meanwhile, the heater 330 may be a freezer compartment defrost heater. For example, when only one freezer compartment evaporator 122 is used in the refrigerator 100, the freezer compartment defrost heater 330 may operate to remove frost attached to the freezer compartment evaporator 122. To this end, the heater driver 332 may control the operation of the heater 330. Meanwhile, the controller 310 may control the heater driver 332.
  • Meanwhile, the heater 330 may include a freezer compartment defrost heater and a refrigerating compartment defrost heater. For example, when the freezer compartment evaporator 122 and the refrigerating compartment evaporator (not shown) are separately used in the refrigerator 100, the freezer compartment defrost heater 330 may operates to remove frost attached to the freezer compartment evaporator 122, and the refrigerating compartment defrost heater (not shown) may operate to remove frost attached to the refrigerating compartment evaporator. To this end, the heater driver 332 may control the operations of the freezer compartment defrost heater 330 and the refrigerating compartment defrost heater.
  • FIG. 5A is a perspective view illustrating an example of an evaporator related to the present disclosure, and FIG. 5B is a diagram referenced in the description of FIG. 5A.
  • First, referring to FIG. 5A, the evaporator 122 in the refrigerator 100 may be a freezer compartment evaporator as described above with reference to FIG. 2 .
  • A sensor mounter 400 including a temperature sensor 320 may be attached to the evaporator 122 in the refrigerator 100.
  • In the drawing, it is illustrated that a sensor mounter 400 is attached to an upper cooling pipe of the evaporator 122 in the refrigerator 100.
  • The evaporator 122 includes a cooling pipe 131 extending from one side of the accumulator 134 and a support 133 supporting the cooling pipe 131.
  • The cooling pipe 131 may be repeatedly bent in a zigzag manner to form multiple rows and may be filled with a refrigerant.
  • Meanwhile, the defrost heater 330 for defrosting may be disposed in the vicinity of the cooling pipe 131 of the evaporator 122.
  • In the drawing, it is illustrated that the defrost heater 330 is disposed in the vicinity of the cooling pipe 131 in a lower region of the evaporator 122.
  • For example, since frost ICE is formed from a lower region of the evaporator 122 and grows in an upward direction, and thus, preferably, the defrost heater 330 may be disposed in the vicinity of the cooling pipe 131 in the lower region of the evaporator 122.
  • Accordingly, as shown in the drawing, the defrost heater 330 may be disposed in a shape surrounding the cooling pipe 131 of the lower region of the evaporator 122.
  • Meanwhile, FIG. 5B illustrates frost ICE is attached to the evaporator 122.
  • In the drawing, it is illustrated that frost ICE is attached to a central portion and a lower portion of the evaporator 122.
  • In particular, in the drawing, it is illustrated that frost ICE is formed on the defrost heater 330 to cover the defrost heater 330.
  • Meanwhile, when the defrost heater 330 operates, frost ICE is removed from the lower region of the evaporator 122 and may be gradually removed in the direction of the central region.
  • Meanwhile, in the present disclosure, a method for improving defrosting efficiency and power consumption when removing frost ICE, that is, defrosting, is proposed. This will be described with reference to FIG. 6 and the following drawings.
  • FIG. 6 is a flowchart illustrating a method of operating a refrigerator according to an embodiment of the present disclosure.
  • Referring to the drawings, the controller 310 of the refrigerator 100 according to an embodiment of the present disclosure determines whether a defrosting operation start time point for defrosting arrives (S610).
  • For example, the controller 310 of the refrigerator 100 may determine whether a defrosting operation start time point arrives while performing a normal cooling operation mode Pga.
  • The defrosting operation start time point may vary according to a defrost cycle.
  • For example, when the number of opening times a door of the cooling compartment (the refrigerating compartment or the freezer compartment) increases, the amount of cold air supplied in the normal cooling operation mode increases, and accordingly, a rate at which frost is formed on the evaporator 122 may increase.
  • Accordingly, when the number of opening times the door of the cooling compartment (the refrigerating compartment or the freezer compartment) increases, the controller 310 of the refrigerator 100 may control such that a defrost cycle is shortened.
  • That is, when the number of opening times the door of the cooling compartment (the refrigerating compartment or the freezer compartment) increases, the controller 310 of the refrigerator 100 may control the defrosting operation start time point to be shortened.
  • Meanwhile, when a defrosting operation start condition is satisfied, for example, in response to a defrosting operation start time point arriving, the controller 310 of the refrigerator 100 may end the normal cooling operation mode, control to perform a defrost operation mode Pdf, and control the defrost heater 330 to be continuously turned on based on a heater operation mode PddT in the defrost operation mode Pdf (S615).
  • Next, the controller 310 of the refrigerator 100 may be configured to perform a pulse operation mode in which the defrost heater 330 is repeatedly turned on and off by a heater pulse after the defrost heater 330 is continuously turned on (S620).
  • For example, when the defrosting operation start condition is satisfied, the controller 310 of the refrigerator 100 may be configured to perform the defrost operation mode Pdf including a pre-defrost cooling mode Pbd, a heater operation mode PddT, and a post-defrost cooling mode pbf.
  • Also, based on the heater operation mode PddT, based on the defrost operation mode pdf, the controller may be configured to perform a continuous operation mode Pona in which the defrost heater 330 is continuously turned on and a pulse operation mode Ponb in which the defrost heater 330 is repeatedly turned on and off.
  • Meanwhile, the controller 310 controls the defrost heater 330 to be continuously turned on based on the continuous operation mode Pona, and in the ON state of the defrost heater 330, when a change rate of an ambient temperature of the evaporator 122 detected by the temperature sensor 320 is equal to or greater than a first reference value ref1, the controller 310 may enter the pulse operation mode Ponb to control the defrost heater 330 to be turned off. Accordingly, defrosting efficiency and power consumption may be improved.
  • Meanwhile, the controller 310 of the refrigerator 100 may control the defrost heater 330 to be turned on and off based on a change rate of the temperature detected by the temperature sensor 320 when the pulse operation mode Ponb is performed.
  • For example, in response to performing the pulse operation mode Ponb, if the change rate of the temperature detected by the temperature sensor 320 is equal to or greater than the first reference value ref1, the controller 310 of the refrigerator 100 may control the defrost heater 330 to be turned off, and if the change rate of the temperature detected by the temperature sensor 320 is less than or equal to a second reference value ref2 less than the first reference value ref1, the controller 310 may control the defrost heater 330 to be turned on. Accordingly, since defrosting may be performed based on a change rate ΔT of the temperature, defrosting efficiency and power consumption may be improved.
  • Next, the controller 310 of the refrigerator 100 determines whether a pulse operation mode end time point arrives (S630), and if pulse operation mode end time point arrives, the controller 310 turns off the defrost heater 330 (S640).
  • For example, the pulse operation mode end time point may be a time point at which the temperature detected by the temperature sensor 320 falls below a phase-change temperature Trf1.
  • As another example, the pulse operation mode end time point may be an end time point of the defrosting operation or an end time point of the heater operation mode.
  • As such, the continuous operation mode Pona in which the defrost heater 330 is continuously turned on and the pulse operation mode in which the defrost heater 330 is repeatedly turned on and off are controlled to be performed based on the change rate of the temperature detected by the temperature sensor 320, defrosting efficiency and power consumption may be improved by performing defrosting based on the change rate ΔT of the temperature.
  • In particular, since defrosting is performed according to the actual amount of frost of the evaporator 122, defrosting efficiency and power consumption may be improved.
  • FIGS. 7A to 13 are diagrams referenced in the description of FIG. 6 .
  • First, FIG. 7A is a diagram illustrating a defrost heater HT and a switching element RL for driving a defrost heater when one evaporator and one defrost heater are used in the refrigerator 100.
  • Referring to the drawing, when only one freezer compartment evaporator 122 is used in the refrigerator 100, the freezer compartment defrost heater HT may operate to remove frost attached to the freezer compartment evaporator 122.
  • To this end, the switching element RL in the heater driver 332 may control the operation of the defrost heater HT. In this case, the switching element RL may be a relay element.
  • That is, when the switching element RL is continuously turned on, the continuous operation mode Pona in which the defrost heater HT is continuously turned on may be performed, and when the switching element RL is switched On and off, the pulse operation mode Ponb in which the defrost heater HT is repeatedly turned on and off may be performed.
  • Next, FIG. 7B is a diagram illustrating defrost heaters HTa and HTb and switching elements RLa and Rlb for driving the defrost heaters when two evaporators and two defrost heaters are used in the refrigerator 100.
  • When a first defrost heater HTa is a freezer compartment defrost heater, a first switching element RLa in the heater driver 332 may control the operation of the first defrost heater HTa. In this case, the first switching element RLa may be a relay element.
  • That is, when the first switching element RLa is continuously turned on, the continuous operation mode Pona in which the first defrost heater HTa is continuously turned on may be performed, and when the first switching element RLa performs On and off switching, the pulse operation mode Ponb in which the first defrost heater HTa is repeatedly turned on and off may be performed.
  • When a second defrost heater HTb is a refrigerating compartment defrost heater, a second switching element RLb in the heater driver 332 may control the operation of the second defrost heater HTb. In this case, the second switching element RLb may be a relay element.
  • That is, when the second switching element RLb is continuously turned on, the continuous operation mode Ponb in which the second defrost heater HTb is continuously turned on may be performed, and when the second switching element RLb performs On and off switching, the pulse operation mode Ponb in which the second defrost heater HTb is repeatedly turned on and off may be performed.
  • Meanwhile, On and off timings of the first switching element RLa and the second switching element RLb may be different from each other. Accordingly, it is possible to perform the defrosting of the freezer compartment evaporator and the defrosting of the refrigerating compartment evaporator, separately.
  • FIG. 8A is a diagram illustrating an example of a pulse waveform indicating an operation of one defrost heater of FIG. 7A.
  • Referring to the drawings, the horizontal axis of the pulse waveform Psh may represent time and the vertical axis may represent a level.
  • When the defrosting cloud base start time To arrives, while performing the normal cooling operation mode Pga, the controller 310 of the refrigerator 100 may end the normal cooling operation mode Pga and control to perform the defrost operation mode pdf.
  • The defrost operation mode pdf may include a pre-defrost cooling mode Pbd between Toa and Ta, a heater operation mode PddT between Ta and Td, and a post-defrost cooling mode pbf between Td and Te.
  • Meanwhile, after the defrost operation mode pdf is ended, the normal cooling operation mode Pgb is performed again.
  • The defrost heater 330 is turned off in the normal cooling operation mode Pga and the normal cooling operation mode Pgb.
  • Meanwhile, the defrost heater 330 may be turned off in the pre-defrost cooling mode Pbd and the post-defrost cooling mode pbf of the defrost operation mode Pdf.
  • Meanwhile, the defrost heater 330 may be continuously turned on in the continuous operation mode Pona of the heater operation mode PddT, and may be repeatedly turned on and off in the pulse operation mode Ponb of the heater operation mode PddT.
  • The continuous operation mode Pona may be performed between Ta and Tb, and the pulse operation mode Ponb may be performed between Tb and Tc.
  • When only the continuous operation mode is performed and the defrost heater 330 is continuously turned on, if the amount of frost is large, defrosting may not be performed properly or if the amount of frost is small, unnecessary defrosting may be performed, and thus, unnecessary power consumption may be consumed.
  • Accordingly, in the present disclosure, the continuous operation mode Pona and the pulse operation mode Ponb are used in combination. Accordingly, defrosting efficiency and power consumption may be improved.
  • FIG. 8B is a diagram illustrating an example of a pulse waveform indicating an operation of two defrost heaters of FIG. 7B.
  • Referring to the drawing, (a) of FIG. 8B shows a pulse waveform Psha indicating an operation of the freezer compartment defrost heater, and (b) of FIG. 8B shows a pulse waveform Pshb indicating an operation of the refrigerating compartment defrost heater.
  • The pulse waveform Psha of (a) of FIG. 8B may be the same as the pulse waveform Psh of FIG. 8A.
  • Meanwhile, since less frost may occur in the refrigerating compartment evaporator than in the freezer compartment evaporator, an operating section of the refrigerating compartment defrost heater may be less than an operating section of the freezer compartment defrost heater.
  • Referring to the pulse waveform Pshb of (b) of FIG. 8B, a period of continuously turning on in the continuous operation mode Pona in the heater operation mode PddT may be less than a period of the pulse waveform Psha of (a) of FIG. 8B.
  • In addition, referring to the pulse waveform Pshb of (b) of FIG. 8B, an ON/OFF repetition period of the pulse operation mode Ponb in the heater operation mode PddT may be less than the pulse waveform Psha of (a) of FIG. 8B.
  • FIG. 9 is a diagram illustrating an example of cooling power supply and a defrost heater operation in the defrost operation mode Pdf of FIG. 8A.
  • Referring to the drawing, the defrost operation mode pdf may include a pre-defrost cooling mode Pbd between To and Ta, a heater operation mode PddT between Ta and Td, and a post-defrost cooling mode pbf between Td and Te.
  • During a period To to T1 of the pre-defrost cooling mode Pbd, a level of supplied cooling power may be an R level, and during a period T1 to T2, a level of cooling power may be an F level greater than the R level.
  • Also, during a period T2 to T3 of the pre-defrost cooling mode Pbd, the cooling power supply may be stopped.
  • In addition, during a period T3 to Ta in the pre-defrost cooling mode Pbd, a level of supplied cooling power may be the R level.
  • According to the pre-defrost cooling mode Pbd, cooling power supply for compensating for the stoppage of cooling power supply during the heater operation mode PddT is performed.
  • Meanwhile, the cooling power supply may be performed by a compressor, a thermoelectric element, or the like, and in the drawings, it is illustrated that the cooling power supply is performed by an operation of the compressor.
  • During a period To to T2 and T3 to Ta in which cooling power is supplied, the compressor operates, and during a period T2 to T3 in which cooling power is not supplied, the compressor is turned off.
  • Meanwhile, during a period To to T1 in which the R level cooling power is supplied, the refrigerating compartment fan may operate and the freezer compartment fan may be turned off.
  • Meanwhile, during a period from a time point T1, at which the F level cooling power is supplied, to a time point Ta, at which the pre-defrost cooling mode Pbd is ended, the refrigerating compartment fan may be turned off and the freezer compartment fan may be operated.
  • Meanwhile, during the period T2 to Ta, the defrost heater 330 should be maintained in an OFF state.
  • Next, the defrost heater 330 may operate during the period of Ta to Tc in the period of Ta to Td of the heater operation mode PddT.
  • As shown in FIG. 8A, the continuous operation mode Pona may be performed during the period of Ta and Tb of the heater operation mode PddT period, and the heater operation mode PddT may be performed during the Tb and Tc periods.
  • Meanwhile, the defrost heater 330 may be turned off from Tc, which is an end time point of the continuous operation mode Pona, to Td.
  • Meanwhile, during the period of the heater operation mode PddT, the compressor and the refrigerating compartment fan may be turned off.
  • Meanwhile, during the period of the heater operation mode PddT, the freezer compartment fan may be turned off. In particular, it is preferable that the freezer compartment fan is turned off from Tc, which is the end time point of the continuous operation mode Pona, to Td.
  • After the heater operation mode PddT, the post-defrost cooling mode Pbf is performed.
  • During the period of Td to T4 in the post-defrost cooling mode Pbf, a level of the supplied cooling power may be an R+F level, and the largest level of cooling power may be supplied.
  • In addition, during the period of T4 to T6 in the post-defrost cooling mode Pbf, a level of the supplied cooling power may be F level, and the cooling power supply may be stopped during the period T6 to Te.
  • According to the post-defrost cooling mode Pbf, the largest level of cooling power supply may be performed according to the stopping of the cooling power supply during the heater operation mode PddT.
  • During the period of Td to T6 in which cooling power is supplied, the compressor operates, and the compressor is turned off during the period of T6 to Te in which cooling power is not supplied.
  • Meanwhile, during the period of Td to T4 in which the R+F level of cooling power is supplied, the refrigerating compartment fan and the freezer compartment fan may be turned off together.
  • Meanwhile, during the period of T4 to T6 in which the F level cooling power is supplied, the refrigerating compartment fan may be turned off and the freezer compartment fan may be operated.
  • Meanwhile, the level of power consumption in the heater operation mode PddT in FIG. 9 may be greater than the level of power consumption of the R+F level cooling power.
  • FIG. 10 is a diagram illustrating temperature change waveforms of an evaporator in response to the defrost heater being operated only in the continuous operation mode and in response to the continuous operation mode and the pulse operation mode being mixed.
  • In particular, in (a) of FIG. 10 , CVa represents a temperature change waveform in response to the defrost heater being operated only in the continuous operation mode, and CVb represents a temperature change waveform in response to the defrost heater being operated by mixing the continuous operation mode and the pulse operation mode.
  • According to CVa, the defrost heater 330 is continuously turned on, and may be turned off at a time point Tx, as shown in (b) of FIG. 10 .
  • According to CVb, the defrost heater 330 operates during the Pohm period, as shown in (c) of FIG. 10 .
  • That is, during the Ponm period including up to a Tpa time point, the continuous operation mode is performed, and the pulse operation mode is performed during a Pofn period from Tpa to Tpb.
  • Trf1 represents a phase-change temperature, and may be, for example, 0° C. Meanwhile, Trf2 represents a defrost end temperature, for example, may be 5° C.
  • Meanwhile, a region between Trf1 and Trf2 may indicate a defrosting region in which defrosting is actually performed, and a region exceeding Trf2 may indicate an overheating region in which excessive defrosting is performed.
  • In order to actually effectively perform defrosting, it is preferable that a size of the overheating region is reduced and a size of the defrosting region is increased.
  • Accordingly, in the present disclosure, the continuous operation mode and the pulse operation mode of the defrost heater 300 are mixed in order to reduce the size of the overheating region and increase the size of the defrosting region.
  • Meanwhile, the controller 310 may be configured to control a peak temperature arrival point Qd of the evaporator 122 when the continuous operation mode Pona and the pulse operation mode Ponb are performed in the defrost operation mode Pdf to be later than a peak temperature arrival point Qc of the evaporator 122 when the defrost heater 330 is only continuously turned on in the defrost operation mode Pdf. Accordingly, it is possible to improve the defrosting efficiency and power consumption when the continuous operation mode Pona and the pulse operation mode Ponb are performed.
  • Meanwhile, the controller 310 may be configured to control a size of a second section Arbb related to a temperature versus time between a phase-change temperature Trf1 and a defrost end temperature Trf2 in response to the continuous operation mode and the pulse operation mode being performed in the defrost operation mode Pdf to be greater than a size of a first section Arab related to a temperature versus time between the phase-change temperature Trf1 and the defrost end temperature Trf2 in response to the defrost heater being only continuously turned on in the defrost operation mode Pdf. Accordingly, it is possible to improve the defrosting efficiency and power consumption when the continuous operation mode Pona and the pulse operation mode Ponb are performed.
  • Meanwhile, the controller 310 may be configured to control an effective defrost when the continuous operation mode Pona and the pulse operation mode Ponb are performed in the defrost operation mode Pdf to be greater than an effective defrost when the defrost heater 330 is only continuously turned on in the defrost operation mode Pdf. Accordingly, it is possible to improve the defrosting efficiency and power consumption when the continuous operation mode Pona and the pulse operation mode Ponb are performed.
  • Meanwhile, the controller 310 may be configured to control a heater OFF time point Tpb when the continuous operation mode Pona and the pulse operation mode Ponb are performed in the defrost operation mode Pdf to be later than a heater OFF time point Tx when the defrost heater 330 is only continuously turned on in the defrost operation mode Pdf. Accordingly, it is possible to improve the defrosting efficiency and power consumption when the continuous operation mode Pona and the pulse operation mode Ponb are performed.
  • Meanwhile, the controller 310 may be configured to control a period Tpb-Qd between the heater OFF time point Tpb and a peak temperature arrival time Qd of the evaporator 122 when the continuous operation mode Pona and the pulse operation mode Ponb are performed in the defrost operation mode Pdf to be greater than a period Tx-Qc between the heater OFF time point and the peak temperature arrival time Qc of the evaporator 122 when the defrost heater 330 is only continuously turned on in the defrost operation mode Pdf. Accordingly, it is possible to improve the defrosting efficiency and power consumption when the continuous operation mode Pona and the pulse operation mode Ponb are performed.
  • Meanwhile, the controller 310 may be configured to control a period Tpb-Qh during which a temperature maintains above the phase-change temperature Trf1 when the continuous operation mode Pona and the pulse operation mode Ponb are performed in the defrost operation mode Pdf to be greater than a period Tx-Qg during which a temperature maintains above the phase-change temperature Trf1 when the defrost heater 330 is only continuously turned on in the defrost operation mode Pdf. Accordingly, it is possible to improve the defrosting efficiency and power consumption when the continuous operation mode Pona and the pulse operation mode Ponb are performed
  • Meanwhile, the controller 310 may be configured to control a period Tpb-Qh between the heater OFF time point Tpb to a time point at which a temperature falls below a phase-change temperature Trf1 when the continuous operation mode Pona and the pulse operation mode Ponb are performed in the defrost operation mode Pdf to be less than a period Tx-Qg between the heater OFF time point Tx to a time point Qg at which the temperature falls below the phase-change temperature Trf1 when the defrost heater 330 is only continuously turned on in the defrost operation mode Pdf. Accordingly, it is possible to improve the defrosting efficiency and power consumption when the continuous operation mode Pona and the pulse operation mode Ponb are performed.
  • Meanwhile, the controller 310 may be configured to control a size of an overheat temperature region Arba equal to higher than the defrosting end temperature Trf2 when the continuous operation mode Pona and the pulse operation mode Ponb are performed in the defrost operation mode Pdf to be less than an overheat temperature region Araa equal to higher than the defrosting end temperature Trf2 when the defrost heater 330 is only continuously turned on in the defrost operation mode Pdf. Accordingly, it is possible to improve the defrosting efficiency and power consumption when the continuous operation mode Pona and the pulse operation mode Ponb are performed.
  • In FIG. 10 , (d) shows a cooling power supply waveform COa in the case of only continuously turning on the defrost heater 330 and a cooling power supply waveform COb in the case of performing a continuous operation mode Pona and a pulse operation mode Ponb.
  • Referring to the drawing, the controller 310 may be configured to control a cooling power supply time point Tcb according to a normal cooling operation mode Pga when the continuous operation mode Pona and the pulse operation mode Ponb are performed in the defrost operation mode Pdf to be later than a cooling power supply time point Tca according to the normal cooling operation mode Pga when the defrost heater 330 is only continuously turned on in the defrost operation mode Pdf.
  • Accordingly, it is possible to improve the defrosting efficiency and power consumption. Accordingly, it is possible to improve the defrosting efficiency and power consumption when the continuous operation mode Pona and the pulse operation mode Ponb are performed.
  • FIG. 11 is a diagram illustrating an operating method in a pulse operation mode according to an embodiment of the present disclosure.
  • Referring to the drawing, the controller 310 controls the defrost heater 330 to be turned on based on the heater operation mode, in particular, based on the continuous operation mode (S1115).
  • Next, the controller 310 calculates a change rate ΔT of a temperature detected by the temperature sensor 320 during the operation of the defrost heater 330, and determines whether the change rate ΔT of the temperature is equal to or greater than a first reference value ref1 (S1120).
  • For example, when the change rate ΔT of the temperature during the continuous operation of the defrost heater 330 is less than the first reference value ref1, the controller 310 may control the defrost heater 330 to continuously operate.
  • Meanwhile, when the change rate ΔT of the temperature during the continuous operation of the defrost heater 330 is equal to or greater than the first reference value ref1, the controller 310 may temporarily turn off the defrost heater 330 (S1125).
  • Next, the controller 310 calculates the change rate ΔT of the temperature detected by the temperature sensor 320 after the defrost heater 330 is temporarily turned off, and determine whether the change rate ΔT of the temperature is less than or equal to a second reference value ref2 (S1128).
  • When the change rate ΔT of the temperature detected by the temperature sensor 320 is less than or equal to the second reference value ref2 after the defrost heater 330 is temporarily turned off, the controller 310 is configured to turn on the defrost heater. That is, the controller 310 controls to perform step S1115.
  • As such, when steps 1115 to 1128 are repeated, the pulse operation mode of the defrost heater 330 is performed.
  • Meanwhile, in step S1128, after the defrost heater 330 is temporarily turned off, when the change rate ΔT of the temperature exceeds the second reference value ref2, the controller 310 determines a pulse operation mode end condition is met. When the pulse operation mode end condition is met (S1130), the controller 310 ends the pulse operation mode and controls the heater to be turned off (S1140).
  • The pulse operation mode end condition may correspond to the pulse operation mode time point.
  • For example, the pulse operation mode end time point may be a time at which the temperature detected by the temperature sensor 320 falls below the phase-change temperature Trf1.
  • As another example, the pulse operation mode end time point may be an end time point of the defrosting operation or an end time point of the heater operation mode.
  • Meanwhile, when the defrosting operation start time point To arrives, the controller 310 controls to perform the defrost operation mode Pdf and controls to perform the continuous operation mode Pona in which the defrost heater 330 is continuously turned on and the pulse operation mode Ponb in which the defrost heater 330 is repeatedly turned on and off based on the defrost operation mode Pdf, and in response to performing the pulse operation mode Ponb, the controller controls the defrost heater 330 to be turned on and off based on the change rate ΔT of the temperature detected by the temperature sensor 320. Accordingly, since defrosting may be performed based on the change rate ΔT of the temperature, it is possible to improve defrost efficiency and power consumption.
  • In particular, since defrosting is performed according to the actual amount of frost ICE of the evaporator 122, it is possible to improve defrost efficiency and power consumption.
  • Meanwhile, the controller 310 may be configured to perform the continuous operation mode Pona or the pulse operation mode Ponb based on the change rate ΔT of the temperature detected by the temperature sensor 320. Accordingly, it is possible to improve the defrosting efficiency and power consumption.
  • Meanwhile, the controller 310 may be configured to operate the heater with power inversely proportional to the change rate ΔT of the temperature detected by the sensor during the pulse operation mode Ponb. Accordingly, it is possible to improve the defrosting efficiency and power consumption.
  • Meanwhile, the controller 310 may be configured to decrease a period of performing the defrost operation mode Pdf as the number of opening times the cooling compartment door increases. Accordingly, it is possible to improve the defrosting efficiency and power consumption.
  • FIG. 12A is a diagram showing a temperature waveform of the evaporator when there is a large amount of frost formation.
  • In FIG. 12A, (a), CVma represents a temperature change waveform in response to the defrost heater being operated only in the continuous operation mode, and CVmb represents a temperature change waveform in response to the defrost heater being operated by mixing the continuous operation mode and the pulse operation mode.
  • According to CVma, the defrost heater 330 may be continuously turned on, and may be turned off at a time point Tmg, as shown in (b) of FIG. 12A.
  • According to CVmb, as shown in (c) of FIG. 12A, the defrost heater 330 is continuously turned on during a Tma period and turned off during Tma and Tmb, during Tmc and Tmd, during Tme and Tmf, and during Tmg and Tmh, and the defrost heater 330 is turned on during Tmb and Tmc, during Tmd and Tme, during Tmf and Tmg, and during Tmh and Tmi.
  • That is, from Tma to Tmi, the defrost heater 330 operates in the pulse operation mode.
  • Meanwhile, the controller 310 controls the defrost heater 330 to be continuously turned on based on the continuous operation mode Pona, and in the ON state of the defrost heater 330, when the change rate ΔT of the ambient temperature of the evaporator 122 detected by the temperature sensor 320 is equal to or greater than the first reference value ref1, the controller 310 may enter the pulse operation mode Ponb and control the defroster heater 330 to be turned off. Accordingly, it is possible to improve the defrosting efficiency and power consumption.
  • Meanwhile, when the defrost heater 330 is turned off during the pulse operation mode Ponb and the change rate ΔT of the temperature around the evaporator 122 is equal to or less than the second reference value ref2 less than the first reference value ref1, the controller 310 may control the defrost heater 330 to be turned on. Accordingly, it is possible to improve the defrosting efficiency and power consumption.
  • Meanwhile, when the defrost heater 330 is turned on during the pulse operation mode Ponb and the change rate ΔT of the temperature around the evaporator 122 is equal to or greater than the first reference value ref1, the controller 310 may control the defrost heater 330 may to be turned on. Accordingly, it is possible to improve the defrosting efficiency and power consumption.
  • Meanwhile, the controller 310 may control the defrost heater 330 to be continuously turned on based on the continuous operation mode Pona, and based on the pulse operation mode Ponb, the controller 310 may repeatedly turned on and off the defrost heater 320 so that the change rate ΔT of the temperature around the evaporator 122 may be between the first reference value ref1 and the second reference value ref2. Accordingly, it is possible to improve the defrosting efficiency and power consumption.
  • FIG. 12B is a diagram showing a temperature waveform of the evaporator when the amount of frost formation is less than that of FIG. 12A.
  • In (a) of FIG. 12B, CVna represents a temperature change waveform in response to the defrost heater being operated only in the continuous operation mode, and CVnb represents a temperature change waveform in response to the defrost heater being operated by mixing the continuous operation mode and the pulse operation mode.
  • According to CVna, the defrost heater 330 may be continuously turned on and may be turned off at a time point Tng, as shown in (b) of FIG. 12B.
  • According to CVnb, as shown in (c) of FIG. 12 b , the defrost heater 330 is continuously turned on during a period of Tna, and the defrost heater 330 is turned off during Tna and Tnb, during Tnc and Tnd, during Tne and Tnf, and during Tng and Tnh, and turned on during Tnb and Tnc, during Tnd and Tne, during Tnf and Tng, and during Tnh and Tni.
  • That is, from Tna to Tni, the defrost heater 330 operates in the pulse operation mode.
  • FIG. 13 is a view showing a region requiring cooling power supply and a region requiring defrosting according to temperatures of the refrigerating compartment and the freezer compartment.
  • Referring to the drawing, the horizontal axis may indicate a temperature of the refrigerating compartment, and the vertical axis may indicate a temperature of the freezer compartment.
  • When a temperature is equal to or lower than a reference temperature of the freezer compartment refma, it may indicate that a freezing capacity is sufficient, and when the temperature is equal to or lower than a reference temperature of the refrigerating compartment refmb, it may indicate that cooling capacity of the refrigerating compartment is sufficient.
  • An Arma region in the drawing is a region in which freezing capacity of the freezer compartment and cooling capacity of the refrigerating compartment are sufficient, and may be a region requiring defrosting.
  • Accordingly, when the defrosting required region is satisfied based on the temperature of the refrigerating compartment and the freezer compartment, the controller 310 may be configured to perform the continuous operation mode and the pulse operation mode described above. In particular, ON/OFF of the defrost heater 330 in the pulse operation mode may be controlled based on a temperature change rate around the evaporator 122.
  • Meanwhile, the Armb region in the drawing may be a region in which both cooling power of the freezer compartment and cooling power of the refrigerating compartment are insufficient, and may be a cooling power supply requiring region requiring cooling power supply.
  • Accordingly, the controller 310 may control supply of cooling power. For example, a compressor may be operated or a thermoelectric element may be operated to control supply of cooling power.
  • FIG. 14 is a flowchart illustrating a method of operating a defrost heater according to another embodiment of the present disclosure, and FIGS. 15A to 15D are diagrams referenced in the description of FIG. 14 .
  • First, referring to FIG. 14 , the controller 310 of the refrigerator 100 according to an embodiment of the present disclosure determines whether a defrosting operation start time point arrives for defrosting (S610).
  • For example, the controller 310 of the refrigerator 100 may determine whether a defrosting operation start time point arrives, while performing the normal cooling operation mode Pga. The defrosting operation start time point may vary according to a defrost cycle.
  • Meanwhile, when a defrosting operation start condition is satisfied, for example, in response to a defrosting operation start time point arriving, the controller 310 of the refrigerator 100 may end the normal cooling operation mode and control to perform the defrost operation mode Pdf.
  • Meanwhile, the defrost operation mode Pdf may include a pre-defrost cooling mode Pbd, a heater operation mode PddT, and a post-defrost cooling mode pbf.
  • Meanwhile, the heater operation mode PddT may include a continuous operation mode Pona in which the defrost heater 330 is continuously turned on, and a pulse operation mode Ponb in which the defrost heater 330 is repeatedly turned on and off.
  • Meanwhile, the controller 310 of the refrigerator 100 may control the defrost heater 330 to be continuously turned on based on the heater operation mode PddT in the defrost operation mode Pdf (S615).
  • In particular, the controller 310 may control the defrost heater 330 to be continuously turned on based on the continuous operation mode Pona in the heater operation mode PddT.
  • Next, the controller 310 of the refrigerator 100 may control the pulse operation mode Ponb, in which the defrost heater 330 is repeatedly turned on and off, to be performed by a heater pulse after the defrost heater 330 is continuously turned on (S620).
  • Meanwhile, while performing the pulse operation mode Ponb, the controller 310 may determine whether the return condition to the continuous operation mode is satisfied (S623), and if so, control the continuous operation mode to be performed again.
  • For example, when the switching element RL of FIG. 7A is continuously turned on and off, the possibility of loss of the switching element RL may increase. Accordingly, the controller 310 may control the pulse operation mode to end, and the continuous operation mode to be performed again.
  • Accordingly, even in the pulse operation mode Ponb, when the defrosting of the frost is not smoothly performed, the defrosting may be stably performed.
  • Next, the controller 310 of the refrigerator 100 determines whether it is the pulse operation mode end time point (S630), and if so, turns off the defrost heater 330 (S640).
  • For example, the pulse operation mode end point time may be a time point at which the temperature detected by the temperature sensor 320 falls below the phase change temperature Trf1.
  • As another example, the pulse operation mode end time point may be a defrost operation end time point or a heater operation mode end time point.
  • Meanwhile, without determining the return condition to the continuous operation mode in step 623, after performing the pulse operation mode Ponb, it is also possible to re-perform the continuous operation mode Ponc.
  • For example, the controller 310 may control the continuous operation mode Ponc to be performed again after performing the pulse operation mode Ponb for stable defrosting. Accordingly, it is possible to improve the defrosting efficiency and reduce the power consumption. In particular, since the defrosting is performed according to the amount of frost of the actual evaporator, it is possible to improve defrosting efficiency and power consumption.
  • Meanwhile, while performing the pulse operation mode Ponb in step 623, a method of determining whether the return condition to the continuous operation mode is satisfied, various examples are possible.
  • For example, when the value related to the temperature detected by the temperature sensor 320 does not reach the reference value while performing the pulse operation mode Ponb, the controller 310 may determine that the defrosting is not smooth, and control the continuous operation mode Ponc to be performed for quick defrosting. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • Meanwhile, when the temperature detected by the temperature sensor 320 is below the reference temperature while performing the pulse operation mode Ponb, the controller 310 may control the continuous operation mode Ponc to be performed for quick defrosting. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • Meanwhile, when the change rate □T of the temperature detected by the temperature sensor 320 is below the reference temperature □T while performing the pulse operation mode Ponb, the controller 310 may determine that the defrosting is not smooth, and control the continuous operation mode Ponc to be performed for quick defrosting. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • Meanwhile, when the temperature detected by the temperature sensor 320 does not reach the target temperature within a certain time while performing the pulse operation mode Ponb, the controller 310 may determine that the defrosting is not smooth, and control the continuous operation mode Ponc to be performed for quick defrosting. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • Meanwhile, when a sum Ma+Mb+ . . . Mn of the ON time of the defrost heater 330 is above the reference level while performing the pulse operation mode Ponb, the controller 310 may determine that the defrosting is not smooth, and control the continuous operation mode Ponc to be performed for quick defrosting. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • Meanwhile, when a sum of the number of opening times of turn on of the defrost heater 330 is above the reference level while performing the pulse operation mode Ponb, the controller 310 may determine that the defrosting is not smooth, and control the continuous operation mode Ponc to be performed for quick defrosting. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • Meanwhile, when the sum Ma+Mb+ . . . , Mn of the ON time of the defrost heater 330 is greater than the sum Mo of the continuous ON time of the defrost heater 330 of the continuous operation mode while performing the pulse operation mode Ponb, the controller 310 may determine that the defrosting is not smooth, and control the continuous operation mode Ponc to be performed for quick defrosting. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • Meanwhile, when the open period is greater than or equal to the allowable period while performing the pulse operation mode Ponb, the controller 310 may determine that the defrosting is not smooth, and control the continuous operation mode Ponc to be performed for quick defrosting. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • Meanwhile, when the humidity in the refrigerator is greater than or equal to the reference humidity while performing the pulse operation mode Ponb, the controller 310 may determine that the defrosting is not smooth, and control the continuous operation mode Ponc to be performed for quick defrosting. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • FIG. 15A is a diagram illustrating an example of a pulse waveform indicating an operation of a defrost heater according to an embodiment of the present disclosure.
  • Referring to the drawing, a horizontal axis of a pulse waveform Pshm may indicate time, and a vertical axis may indicate a level.
  • When a defrosting operation start time point To arrives while performing the normal cooling operation mode Pga, the controller 310 of the refrigerator 100 may control the normal cooling operation mode Pga to end and the defrost operation mode Pdf to be performed.
  • The defrost operation mode Pdf may include the pre-defrost cooling mode Pbd between Toa and Ta, the heater operation mode PddT between Ta and Td, and the post-defrost cooling mode pbf between Td and Te.
  • Meanwhile, after the defrost operation mode Pdf ends, the normal cooling operation mode Pgb is performed again.
  • The defrost heater 330 is turned off in the normal cooling operation mode Pga and the normal cooling operation mode Pgb.
  • Meanwhile, the defrost heater 330 may be turned off in the pre-defrost cooling mode Pbd and the post-defrost cooling mode pbf of the defrost operation mode Pdf.
  • Meanwhile, the defrost heater 330 may be continuously turned on in the continuous operation mode Pona in the heater operation mode PddT, may repeat the turn on and off in the pulse operation mode Ponb in the heater operation mode PddT, and may be continuously turned on in the continuous operation mode Ponc in the heater operation mode PddT.
  • Unlike FIG. 8A, according to FIG. 15A, after the pulse operation mode Ponb, there is a difference in that the continuous operation mode Ponc is further performed.
  • As described in the description of FIG. 14 , when the return condition to the continuous operation mode Ponc of the defrost heater 330 arrives while performing the pulse operation mode Ponb, the controller 310 may control the continuous operation mode Ponc to be further performed.
  • The continuous operation mode Pona may be performed between Ta and Tb, and the pulse operation mode Ponb may be performed between Tb and Tc.
  • An additional continuous operation mode Ponc may be performed between Tcm and Td. In the drawing, it is exemplified that the period during which the additional continuous operation mode Ponc is performed is Mz.
  • By this additional continuous operation mode Ponc, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • FIG. 15B is a diagram illustrating another example of a pulse waveform indicating an operation of a defrost heater according to an embodiment of the present disclosure.
  • A pulse waveform Pshn of FIG. 15B is similar to the pulse waveform Pshm of FIG. 15A, but the additional continuous operation mode Ponc is different in that it is performed between Tcm and Tcn.
  • In the drawing, it is exemplified that My, which is the duration of the additional continuous operation mode Ponc, is less than Mz of FIG. 15A.
  • The controller 310 may vary the period during which the continuous operation mode Ponc is performed based on the difference between the value related to the temperature detected by the temperature sensor 320 and the reference value. For example, as the difference decreases, it is possible to control the period during which the continuous operation mode Ponc is performed to decrease. By this additional continuous operation mode Ponc, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • Meanwhile, the controller 310 may vary the period during which the continuous operation mode Ponc is performed based on the difference between the temperature detected by the temperature sensor 320 and the reference temperature while performing the pulse operation mode Ponb. For example, as the difference decreases, it is possible to control the period during which the continuous operation mode Ponc is performed to decrease.
  • Meanwhile, the controller 310 may vary the period during which the continuous operation mode Ponc is performed based on the difference between the change rate □T of the temperature detected by the temperature sensor 320 and the change rate □T of the reference temperature while performing the pulse operation mode Ponb. For example, as the difference decreases, it is possible to control the period during which the continuous operation mode Ponc is performed to decrease.
  • Meanwhile, the controller 310 may vary the period during which the continuous operation mode Ponc is performed based on the difference between the temperature detected by the temperature sensor 320 and the target temperature while performing the pulse operation mode Ponb. For example, as the difference decreases, it is possible to control the period during which the continuous operation mode Ponc is performed to decrease.
  • Meanwhile, the controller 310 may vary the period during which the continuous operation mode Ponc is performed based on the difference between the reference level and the sum Ma+Mb+ . . . Mn of the on time of the defrost heater 330 while performing the pulse operation mode Ponb. For example, as the difference decreases, it is possible to control the period during which the continuous operation mode Ponc is performed to decrease.
  • Meanwhile, the controller 310 may vary the period during which the continuous operation mode Ponc is performed based on the difference between the reference number of opening times and the sum of the number of opening times of turn on of the defrost heater 330 while performing the pulse operation mode Ponb. For example, as the difference decreases, it is possible to control the period during which the continuous operation mode Ponc is performed to decrease.
  • Meanwhile, the controller 310 may vary the period during which the continuous operation mode Ponc is performed based on the difference between the sum Mo of the continuous ON time and the sum Ma+Mb+ . . . Mn of the ON time of the defrost heater 330 while performing the pulse operation mode Ponb. For example, as the difference decreases, it is possible to control the period during which the continuous operation mode Ponc is performed to decrease.
  • Meanwhile, the controller 310 may vary the period during which the continuous operation mode Ponc is performed based on the difference between the humidity in the refrigerator and the reference humidity while performing the pulse operation mode Ponb. For example, as the difference decreases, it is possible to control the period during which the continuous operation mode Ponc is performed to decrease.
  • FIG. 15C is a diagram illustrating another example of a pulse waveform indicating an operation of a defrost heater according to an embodiment of the present disclosure.
  • A pulse waveform Psho of FIG. 15 c is similar to the pulse waveform (Pshm) of FIG. 15A, but there is a difference in that after the pulse operation mode Ponb, an additional continuous operation mode Ponab and an additional pulse operation mode ponbb are further performed.
  • In the drawing, it is exemplified that after Tc, an additional continuous operation mode Ponab is performed between Ta′ and Tb′, and an additional pulse operation mode ponbb is performed between Tb′ and Tc′.
  • Meanwhile, the duration of the additional continuous operation mode Ponab is preferably less than the duration of the continuous operation mode Pona.
  • Meanwhile, the duration of the additional pulse operation mode ponbb is preferably less than the duration of the continuous operation mode Ponb. Accordingly, it is possible to improve the defrosting efficiency while stably performing the defrosting.
  • FIG. 16 is a flowchart illustrating a defrosting method according to another embodiment of the present disclosure, and FIGS. 17A to 17D are diagrams referenced in the description of FIG. 16 .
  • First, referring to FIG. 16 , the controller 310 of the refrigerator 100 according to an embodiment of the present disclosure determines whether a defrosting operation start time point arrives for defrosting (S610).
  • For example, the controller 310 of the refrigerator 100 may determine whether it is the defrosting operation start time point, while performing the normal cooling operation mode Pga. The defrosting operation start time point may vary according to a defrost cycle.
  • Meanwhile, when a defrosting operation start condition is satisfied, for example, in response to a defrosting operation start time point arriving, the controller 310 of the refrigerator 100 may end the normal cooling operation mode and control the defrost operation mode Pdf to be performed.
  • Meanwhile, the defrost operation mode Pdf may include a pre-defrost cooling mode Pbd, a heater operation mode PddT, and a post-defrost cooling mode pbf.
  • Meanwhile, the heater operation mode (PddT) may include a continuous operation mode Pona in which the defrost heater 330 is continuously turned on, and a pulse operation mode Ponb in which the defrost heater 330 is repeatedly turned on and off.
  • Meanwhile, the controller 310 of the refrigerator 100 may control the defrost heater 330 to be continuously turned on based on the continuous operation mode Pona in the heater operation mode PddT of the defrost operation mode Pdf (S615).
  • Next, the controller 310 of the refrigerator 100 determines whether the temperature detected by the temperature sensor 320 reaches a first temperature Tm1 within a first period Pm1 while performing the continuous operation mode Pona (S1616).
  • If so, the controller 310 of the refrigerator 100 may control the pulse operation mode, in which the defrost heater 330 is repeatedly turned on and off, to be performed by the heater pulse after the defrost heater 330 is continuously turned on (S1620).
  • (a) of FIG. 17A illustrates an example of a temperature waveform Tcva around the evaporator 122, and (b) of FIG. 17A illustrates an example of an operating waveform Psh of the defrost heater 330.
  • Referring to the drawing, based on the heater operation mode Pon, the continuous operation mode (Pona) is performed during the Pm1 period between Ta and Tb.
  • Meanwhile, when the temperature detected by the temperature sensor 320 reaches the first temperature Tm1 within the first period Pm1, or as illustrated in the drawing, at Tb, which is the end time of the first period Pm1, while performing the continuous operation mode Pona, the controller 310 of the refrigerator 100 may control the pulse operation mode Ponb to be performed after Tb.
  • That is, after the time Tb, the controller 310 of the refrigerator 100 may control the defrost heater 330 to be turned off during the period pf1 and then the defrost heater 330 to be repeatedly turned on and off.
  • As such, when the amount of frost formed on the evaporator 122 is small, after the continuous operation mode Pona is performed, by controlling the pulse operation mode Ponb to be performed, it is possible to improve the defrosting efficiency and reduce the power consumption.
  • Next, the controller 310 of the refrigerator 100 determines whether it is the pulse operation mode end time point (S1630), and if so, turns off the defrost heater 330 (S1640).
  • For example, the pulse operation mode end point time may be a time point at which the temperature detected by the temperature sensor 320 falls below the phase change temperature Trf1.
  • As another example, the pulse operation mode end time point may be a defrost operation end time point or a heater operation mode end time point.
  • Meanwhile, in step S1616, when the temperature detected by the temperature sensor 320 does not reach the first temperature Tm1 within the first period Pm1 while performing the continuous operation mode Pona, step S1617 may be performed.
  • That is, when the temperature detected by the temperature sensor 320 does not reach a first temperature Tm1 within the first period Pm1 while performing the continuous operation mode Pona, the controller 310 of the refrigerator 100 determines whether the first temperature Tm1 arrival period is greater than or equal to the second period (S1617).
  • If so, it is determined that the amount of frost formed on the evaporator 122 is large, and the continuous operation mode Pona may be controlled to be continuously performed (S1623).
  • (b) of FIG. 17A illustrates another example of a temperature waveform Tcvb around the evaporator 122, and (b) of FIG. 17B illustrates another example of an operating waveform Pshb1 of the defrost heater 330.
  • Referring to the drawing, based on the heater operation mode Pon, the continuous operation mode Pona is performed during the period Pm1 between Ta and Tb.
  • Meanwhile, when the temperature detected by the temperature sensor 320 does not reach a first temperature Tm1 within the first period Pm1 while performing the continuous operation mode Pona1, the controller 310 of the refrigerator 100 determines whether the first temperature Tm1 arrival period is greater than or equal to the second period pm2.
  • In the drawing, it is exemplified that the temperature detected by the temperature sensor 320 reaches the end time of the second period pm2.
  • Accordingly, the controller 310 of the refrigerator 100 may control the continuous operation mode Pona1 to be performed during the periods Ta and Tc.
  • In addition, the controller 310 of the refrigerator 100 may control that, during the heater operation mode Pon, only the continuous operation mode Pona1 is performed and the pulse operation mode (Ponb) is not performed. Accordingly, when the amount of frost formed on the evaporator 122 is large, it is possible to control to efficiently perform defrosting.
  • Meanwhile, unlike the drawing, the controller 310 of the refrigerator 100 may control the continuous operation mode Pona1 to be performed during a predetermined period after the period Tc.
  • Meanwhile, after the continuous operation mode Pona1 of FIG. 17B, step S1622 may be performed again.
  • Meanwhile, in step 1617, when the first temperature Tm1 arrival period of the temperature detected by the temperature sensor 320 is not greater than or equal to the second period but is between the first period and the second period while performing the continuous operation mode Pona, step S1618 may be performed
  • That is, the controller 310 of the refrigerator 100 determines whether the temperature detected by the temperature sensor 320 reaches the second temperature Tm2 between the first period and the second period while performing the continuous operation mode Pona (S1618). If so, the defrost heater is turned off (S1619), and the defrost heater may be controlled to be turned on and off based on the pulse operation mode (S1621).
  • (a) of FIG. 17C illustrates another example of a temperature waveform Tcvc around the evaporator 122, and (b) of FIG. 17C illustrates another example of an operating waveform Pshb2 of the defrost heater 330.
  • Referring to the drawing, based on the heater operation mode Pon2, the continuous operation mode is performed during the period Pm1 between Ta and Tb.
  • Meanwhile, when the temperature detected by the temperature sensor 320 does not reach the first temperature Tm1 within the first period Pm1 while performing the continuous operation mode, the controller 310 of the refrigerator 100 determines whether the first temperature Tm1 arrival period is greater than or equal to the second period pm2 or between the first period pm1 and the second period pm2.
  • In the drawing, it is exemplified that the temperature detected by the temperature sensor 320 reaches the first temperature Tm1 in Tk between the first period pm1 and the second period pm2, and the temperature detected by the temperature sensor 320 reaches the second temperature Tm2 in Tm between the first period pm1 and the second period pm2.
  • Accordingly, the controller 310 of the refrigerator 100 may be configured to perform the continuous operation mode until the time point Tm at which a temperature reaches the second temperature Tm2
  • In addition, after the first OFF of the defrost heater 330 after the time point Tm, the pulse operation mode Ponb2 may be controlled to be performed.
  • Meanwhile, as the continuous operation mode continues, in consideration of the heat of the switching element RL of FIG. 7A, tit is preferable that the first OFF period psf2 of the defrost heater 330 after the time point Tm is greater than the OFF period during the On and off of the pulse operation mode Ponb2.
  • Meanwhile, it is preferable that the first OFF period psf2 of the defrost heater 330 after the time point Tm when the pulse operation mode Ponb2 is performed is greater than the first OFF period pof1 of the defrost heater 330 after the time point Tb when the pulse operation mode Ponb of FIG. 17A is performed. Accordingly, it is possible to protect the switching element RL of FIG. 7A and the like.
  • Meanwhile, according to FIGS. 17A to 17C, the controller 310 may be configured to, as the change rate of the temperature detected by the temperature sensor 320 decreases while performing the continuous operation mode Pon, increase a delay of the start time point of the pulse operation mode Ponb.
  • That is, compared to FIG. 17A, in the case of FIG. 17C, the change rate of the temperature detected by the temperature sensor 320 is smaller, and accordingly, the start time point of the pulse operation mode is further delayed.
  • Meanwhile, compared to FIG. 17C, in the case of FIG. 17B, the change rate of the temperature detected by the temperature sensor 320 is smaller, and accordingly, the pulse operation mode may not start at all.
  • Meanwhile, the controller 310 may be configured to, as the change rate of the temperature detected by the temperature sensor decreases while performing the continuous operation mode Pona, increase the duration of the pulse operation mode Pona.
  • For example, compared to FIG. 17A, in the case of FIG. 17C, the change rate of the temperature detected by the temperature sensor 320 is smaller, and accordingly, the duration of the continuous operation mode is a period between Ta and Tm, and is greater than the period between Ta and Tb of FIG. 17A.
  • Meanwhile, compared to FIG. 17C, in the case of FIG. 17B, the change rate of the temperature detected by the temperature sensor 320 is smaller, and accordingly, the duration of the continuous operation mode is a period between Ta and Tc, and is greater than the period between Ta and Tm of FIG. 17B. Accordingly, it is possible to efficiently perform the defrosting.
  • Meanwhile, unlike FIGS. 17A to 17C, when the temperature detected by the temperature sensor 320 reaches the first temperature Tm1 between the first period Pm1 and the period Pm2 while performing the continuous operation mode, the controller 310 may control the pulse operation mode Ponb to be performed after the defrost heater 310 is turned off without determining whether the second period Pm2 arrives.
  • The controller 310 may be configured to control the OFF period of the defrost heater 310 before the pulse operation mode Ponb is performed when the temperature detected by the temperature sensor 320 reaches the first temperature Tm1 between the first period Pm1 and the second period Pm2 to be greater than the OFF period of the defrost heater 310 before the pulse operation mode Ponb is performed when the temperature detected by the temperature sensor 320 reaches the first temperature Tm1 within the first period Pm1. Accordingly, it is possible to efficiently perform the defrosting.
  • In the refrigerator according to the present disclosure, the configuration and the method of the embodiments as described above are not restrictively applied. Rather, all or some of the embodiments may be selectively combined with each other so that the embodiments may be variously modified.
  • In addition, although the preferred embodiments of the present disclosure have been illustrated, the present disclosure is not limited to the specific embodiments described above, and can be variously modified by those skilled in the art to which the present disclosure pertains without departing from the gist of the present disclosure claimed in the claims, and these modifications should not be understood individually from the technical ideas or prospects of the present disclosure.
  • INDUSTRIAL APPLICABILITY
  • The present disclosure can be applied to a refrigerator, and more particularly, can be applied to a refrigerator capable of improving defrosting efficiency and power consumption.

Claims (20)

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.
US17/923,485 2020-05-07 2021-04-21 Refrigerator Pending US20230160625A1 (en)

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KR1020200054351A KR20210136303A (en) 2020-05-07 2020-05-07 Refrigerator
PCT/KR2021/005055 WO2021225308A1 (en) 2020-05-07 2021-04-21 Refrigerator

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