JP2015042924A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerator capable of saving power consumption by eliminating wasteful electric conduction of a defrosting heater by executing a defrosting operation optimally according to the amount of frost formation.SOLUTION: A refrigerator includes: an outdoor temperature sensor for detecting an outdoor temperature; a temperature sensor for defrosting for detecting a temperature of a cooler or its vicinity; and a control unit for ending a defrosting operation when the temperature detected by the temperature sensor for defrosting has reached a preset temperature for defrosting end determination. The control unit determines whether the temperature detected by the temperature sensor for defrosting is lower than a first preset temperature, or higher than a second preset temperature which is higher than the first preset temperature. When the temperature is lower than the first preset temperature or higher than the second preset temperature, it performs the defrosting operation at the first defrosting preset temperature. When the temperature is between the first preset temperature and the second preset temperature, it performs the defrosting operation at the second defrosting preset temperature which is lower than the first defrosting preset temperature.

Description

  Embodiment of this invention is related with the refrigerator provided with the function to remove the frost adhering to a cooler automatically.

  Conventionally, when the refrigerator reaches a set temperature for determining the end of defrosting, the defrosting operation is ended. After the defrosting operation, if the door is not opened until the next defrosting operation is started, the set temperature for determining the completion of the defrosting is set low. Thereby, when there is little frost formation, defrosting time can be shortened and power saving can be aimed at.

  However, the refrigerator is operated so as to cool the inside of the refrigerator when the outdoor temperature is high, such as in summer, or when the number of times of opening and closing the door is large. In such a refrigerator, the operation of the defrost heater is performed in the same way when the amount of frost formation is large and when the load to cool the interior with a non-open door is light and the amount of frost formation on the cooler is small. It was. For this reason, there has been a problem that wasteful power consumption occurs.

JP-A-8-261629

  The problem to be solved by the present invention is to provide a refrigerator in which the defrosting operation is optimally executed according to the degree of frost formation to eliminate unnecessary energization of the defrost heater and to save power consumption. is there.

  The refrigerator of the embodiment includes an outside air temperature sensor that detects the outside air temperature, a defrosting temperature sensor that detects the temperature of the cooler or the vicinity thereof, and a temperature detected by the defrosting temperature sensor, and the defrosting end determination. And a controller that terminates the defrosting operation when the set temperature is reached, wherein the temperature detected by the defrosting temperature sensor is lower than the first set temperature. It is determined whether the temperature is higher than the second set temperature higher than the first set temperature. When the temperature is lower than the first set temperature or higher than the second set temperature, the defrost is performed at the first defrost set temperature. An operation is performed, and when the temperature is between the first set temperature and the second set temperature, the defrost operation is performed at a second defrost set temperature lower than the first defrost set temperature.

It is an external view of the state seen from the front for demonstrating the refrigerator concerning 1st Embodiment. It is sectional drawing of FIG. It is a front view for demonstrating a cooler. It is a block diagram which shows the control system of a refrigerator. It is a flowchart for demonstrating the defrost operation of embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

(First embodiment)
Drawing 1 is an outline view seen from the front for explaining the refrigerator concerning a 1st embodiment. The refrigerator shown in FIG. 1 is a double door type, and shows a state in which a door is opened. FIG. 2 is a cross-sectional view of FIG.

  As shown in FIG. 1, the refrigerator 100 includes a plurality of compartments in a refrigerator body 11 that is a heat insulating box. Specifically, by partitioning the inside of the refrigerator with heat insulating partition plates 12a to 12c (see FIG. 2), the refrigerator compartment 13, the ice making chamber 14, the upper freezer compartment 15, the vegetable compartment 16, and the lower freezer compartment 17 from above. I have. The ice making chamber 14 and the upper freezing chamber 15 are partitioned by a vertical heat insulating partition plate (not shown).

  The opening of each chamber is formed of a metal material that is attracted to the magnet. In the opening of each chamber, for example, a heat insulating door filled with a foam heat insulating material such as hard urethane foam is provided.

  The refrigerator compartment 13 is provided with a left door 13a and a right door 13b that block the opening of the heat insulating box. The left door 13a is pivotally supported by a hinge 18a, and the right door 13b is pivotally supported by a hinge 18b. The refrigerating room 13 can take out items stored in the width direction by opening the left door 13a and / or the right door 13b.

  The ice making room 14, the upper freezing room 15, the vegetable room 16, and the lower freezing room 17 are drawer-type rooms, and drawer-type doors 141, 151, 161, and 171 are provided on the front surfaces thereof. ing.

  An automatic ice making device (not shown) is provided in the ice making chamber 14, and a water supply device (not shown) for supplying a certain amount of water to the ice tray of the automatic ice making device is provided in the refrigeration chamber 13. An ice storage container (not shown) is connected to the back surface of the door 141.

  As shown in FIG. 2, a freezing container 152 is disposed on the back surface of the door 151. A storage container 162 is connected to the rear surface of the door 161. A storage container 172 is connected to the back surface of the door 171. A refrigeration cooler chamber 25 and a freezer cooler chamber 26 are provided on the back wall of the vegetable chamber 16 so as to overlap in two stages. In the refrigeration cooler chamber 25, a refrigeration cooler 27 and a refrigeration blower fan 28 for cooling the refrigeration chamber 13 and the vegetable compartment 16 are provided.

  When the refrigeration blower fan 28 is driven, the cold air generated by the refrigeration cooler 27 is supplied from the upper part of the refrigeration cooler chamber 25 through the blower duct 29 into the refrigeration chamber 13 through a plurality of outlets. After being supplied into the vegetable compartment 16, circulation is performed to return to the lower part of the refrigeration cooler compartment 25. Thus, the inside of the refrigerator compartment 13 and the vegetable compartment 16 is cooled to a refrigerator temperature zone of, for example, 3 ° C to 5 ° C.

  In the freezer compartment cooling chamber 26, a freezer cooler 30 and an unillustrated freezing blower fan for cooling the lower freezer compartment 17 and the ice making chamber 14 are provided. When the refrigeration blower fan is driven, the cold air generated by the refrigeration cooler 30 is supplied from the refrigeration cooler chamber 26 into the ice making chamber 14 and the lower freezing chamber 17 through the blower duct, and then cooled for refrigeration. Circulation returning to the chamber 26 is performed. Thus, the ice making chamber 14 and the lower freezing chamber 17 are cooled to a freezing temperature zone of, for example, −18 ° C. or lower.

  Furthermore, the operation display panel 7 (refer FIG. 2) which alert | reports the driving | running state of the refrigerator main body 11 is attached to the outer surface of the door 13b for refrigerator compartments. The operation display panel 7 is provided with a display indicating the operating state of the refrigerator or freezer of the refrigerator main body 11, a temperature adjustment indicator for displaying the strength of the set temperature in the refrigerator, and the like. Further, the operation display panel 7 is provided with switches for temperature adjustment such as a refrigerator and a freezer.

  Reference numeral 19 installed at the lower back of the lower freezer compartment 17 is a freezer temperature sensor (see FIG. 2) that detects the temperature of the lower freezer compartment 17. The freezer temperature sensor 19 detects the temperature of the lower freezer room 17. In addition, although the temperature sensor for refrigerator compartments is attached to the back surface of the refrigerator compartment 13 in order to detect the temperature in the refrigerator compartment 13, illustration here is abbreviate | omitted.

  Reference numeral 20 attached to the right door 13b is an outside air temperature sensor (see FIG. 2) serving as a detecting means for detecting the outside air temperature, and is for detecting the temperature of the outside air (outside the refrigerator) of the refrigerator main body 11. Reference numeral 21 denotes a humidity sensor serving as a detecting means for detecting the humidity of the outside air. Note that the outside air temperature sensor 20 and the humidity sensor 21 are attached to positions that are not affected by the internal temperature on the back side of the operation display panel 7, for example.

  FIG. 3 shows an example of the refrigeration cooler 30. The refrigeration cooler 30 is fitted with a large number of rectangular cooling fins 32 made of a thin aluminum plate at predetermined intervals in the longitudinal direction of a refrigerant pipe 31 formed of a long straight pipe. The refrigerant pipe 31 is formed in a rectangular shape by meandering and bending with a predetermined width, and holding and fixing the cooling fins 32 on both sides of the cooling fin 32 with the end plates 33 made of aluminum.

  A machine room 5 is provided on the back side of the upper end of the refrigerator body 11. In the machine room 5, a compressor 6 for compressing the refrigerant gas, a condenser for liquefying a high-pressure refrigerant gas (not shown), a cooling fan for cooling them, and the like are disposed.

  The freezer cooler 30 is erected and fixed (see FIG. 2) along the rear back wall of the vegetable compartment 16. Below the refrigeration cooler 30, a drainage basin 9 that receives defrost water and guides it to the evaporating dish 8 placed below the outside of the refrigerator is disposed.

  A defrost heater 34 is disposed in the gap between the refrigeration cooler 30 and the drainage basin 9. The defrost heater 34 is for melting and removing frost attached to the cooler. Both end portions of the defrost heater 34 are insulated and connected to the lead wire 36, and the terminal portion thereof is electrically and watertightly insulated and sealed by a plug 37.

  The defrost heater 34 is engaged and held by a heater cover 38 disposed above the defrost heater 34. The heater cover 38 is formed with a ridge (not shown) having a width and a depth that completely covers the defrost heater 34 from the upper surface so that the defrost water from the refrigeration cooler 30 is not directly dropped onto the defrost heater 34 at the time of defrosting. Has been.

  Furthermore, a defrosting temperature sensor 39 for determining the defrosting state is attached to the refrigeration cooler 30. The defrosting temperature sensor 39 is configured to stop energization of the defrosting heater 34 when a set temperature described later is reached.

  FIG. 4 is a block diagram illustrating a control system of the refrigerator 100.

  In FIG. 4, the control unit 41 is a unit that comprehensively controls the hardware of the refrigerator 100. The control unit 41 includes a processor 411 that is an arithmetic processing unit (for example, a CPU (Central Processing Unit)), and a storage unit 412 that includes a volatile and non-volatile storage unit.

  The processor 411 has a role of controlling the cooling operation in the refrigerator 100 and a function as a defrost control means. The processor 411 also plays a role of realizing various functions by executing a program stored in the storage unit 412.

  The storage unit 412 includes, for example, a RAM (Random Access Memory), a ROM (Read Only Memory), a DRAM (Dynamic Random Access Memory), an SRAM (Static Random Access Memory), and the like.

  The storage unit 412 has a role of storing various information and programs used in the refrigerator 100. The storage unit 412 stores data and programs that need to be stored in a nonvolatile manner.

  Note that the functions realized using the processor 411 and the storage unit 412 may be realized by implementation using an ASIC (Application Specific Integrated Circuit).

  The control unit 41 receives detection information from the freezer temperature sensor 19, the outside air temperature sensor 20, the humidity sensor 21, and the defrosting temperature sensor 39. The temperature information of the lower freezer compartment 17 is received from the freezer temperature sensor 19. From the outside air temperature sensor 20, temperature information of outside air (outside the warehouse) is received. The humidity sensor 21 receives humidity information of the outside air. The defrost information of the refrigeration cooler 30 is received from the defrost temperature sensor 39.

  The control unit 41 compares the temperature and humidity set in advance based on detection information from the freezer temperature sensor 19, the outside air temperature sensor 20, the humidity sensor 21, and the defrosting temperature sensor 39. The control unit 41 is configured to control the drive unit 42 based on the comparison result based on the detection information from each sensor, and to drive the compressor 6, the refrigeration blower fan 28, the defrost heater 35, and the like.

  Here, before explaining the defrosting operation process of the embodiment, frost formation and freezing in the refrigerator 100 will be described. Although the frost formation and freezing of the freezing cooler 30 will be described, the freezing cooler 27 generates frosting and freezing on the same principle.

  First, frost formation will be described. In the refrigerator 100, the internal temperature rises due to, for example, heat inflow from each door opening and closing or a portion having low heat insulation. The higher the outside air temperature, the greater the heat that has entered, and as a result, the temperature inside the refrigerator 100 increases.

  Therefore, the higher the outside air temperature is, the higher the ambient temperature of the refrigeration cooler 30 becomes, and the temperature difference between the ambient cool air of the chiller 30 and the surface temperature of the refrigeration cooler 30 increases. The amount of water that can be contained in the air is higher as the temperature of the air is higher, so the higher the temperature of the surrounding cold air, the more the amount of water contained in the surrounding cold air tends to increase, and the more moisture that causes frost formation. Frosting is likely to be induced. Therefore, the large temperature difference causes the amount of frost formation on the refrigeration cooler 30 to easily increase.

  Next, freezing will be described. The refrigeration cooler 30 is always exposed to the air circulating in the refrigerator 100. For this reason, when the operation of the refrigeration cooler 30 is stopped, the surface temperature of the refrigeration cooler 30 is increased as compared with that during operation. When the surface temperature of the refrigeration cooler 30 is high, the amount of frost that melts out is large, and the melted frost falls into the bowl 9. On the other hand, when the surface temperature of the refrigeration cooler 30 is low, the amount of frost melting is small. Accordingly, once the frost has melted, the refrigeration cooler 30 starts operating before it completely falls toward the ridge 9 and may freeze again in a icy state.

  In this way, the remaining ice that has grown due to the formation of frost or supercooled water partially melts. However, the melted residual ice is cooled by the action of the refrigeration cooler 30 and frozen before being dropped into the bowl 9 as liquid water and drained. Will do.

  For freezing, the inside temperature increases as the outside air temperature increases for the same reason as the explanation of frost formation. The refrigeration cooler 30 is thermally affected by exposure to air circulating in the refrigerator. The refrigeration cooler 30 is more likely to cause a temperature rise on the surface of the cooler 30 when the operation of the cooler 30 is stopped as the outside air temperature is higher.

  Therefore, the lower the outside air temperature, the easier the surface temperature of the refrigeration cooler 30 is maintained, and as a result, freezing tends to occur.

  Next, the defrosting operation of the first embodiment will be described with reference to the flowchart of FIG. In each embodiment, the defrosting operation of the refrigeration cooler 30 will be described, but the same defrosting operation is also performed for the refrigeration cooler 27.

  The flowchart shown in FIG. 5 shows the defrosting operation among the control contents of the control program stored in the storage unit 412 of the control unit 41. Moreover, the flowchart shown in FIG. 5 has shown about the defrost process after completion | finish of the first defrost process in the case of re-energizing after the power activation at the time of product purchase or a power failure.

  First, the temperature detected by the outside air temperature sensor 20 is compared with a preset first outside air set temperature (for example, 10 ° C.) to determine whether the outside air temperature (room temperature) is lower than the set temperature (step S1). . When it is determined that the outside air temperature is higher than 10 ° C. (Yes), the process proceeds to step S2. If it is determined that the outside air temperature is lower than 10 ° C. (No), the process proceeds to step S3.

  In step S2, a temperature higher than 10 ° C. detected by the outside air temperature sensor 20 is compared with a second preset outside air temperature (for example, 30 ° C.) to determine whether the outside air temperature is higher than 30 ° C. If it is determined that the outside air temperature is higher than 30 ° C. (Yes), the process proceeds to step S3.

  In step S3, when the outside air temperature is lower than 10 ° C. or higher than 30 ° C., the humidity detected by the humidity sensor 21 is compared with a preset humidity (for example, 70%). When it determines with humidity being 70% or more (Yes), it transfers to step S4.

  In step S4, it is determined whether or not a preset first set time (for example, 24 hours) has been reached. The compressor 6 during normal cooling operation in the refrigerator 100 performs normal operation when the temperature detected by the freezer temperature sensor 19 rises to the compressor on temperature. The compressor 6 stops operation when the temperature detected by the freezer temperature sensor 19 falls to the compressor off temperature.

  In step S4, when 24 hours are reached, the process proceeds to step S5, and so-called precool operation is performed. In this precooling operation, the compressor 6 and the refrigeration blower fan are forcibly energized for a preset time (for example, 30 minutes) to cool each room.

  Then, when the precool operation for 30 minutes is completed, energization of the defrost heater 35 is started and the defrost operation is started (step S6).

  Subsequently, it is determined whether or not the temperature detected by the defrosting temperature sensor 39 has reached a preset first defrosting setting temperature (for example, 10 ° C.) for determining the completion of defrosting (step S7). In step S <b> 7, the defrost heater 35 is heated until the detected temperature reaches 10 ° C., and the frost attached to the refrigeration cooler 30 is continuously melted and removed.

  Thereafter, when the temperature detected by the defrosting temperature sensor 39 reaches 10 ° C. and it is determined that the defrosting has been sufficiently performed (Yes), the defrosting heater 35 is deenergized and the defrosting operation is terminated (step). S8).

  At the end step of this defrosting operation, it is configured to clear the time measured by a timer built in the control unit 41 for integrating the operation time of the compressor 6. And it returns to step S1 and repeats the control mentioned above.

  Next, a defrosting operation in which the outside air temperature is higher than 10 ° C. and lower than 30 ° C. or the humidity is lower than 70% will be described. When the outside air temperature is 10 ° C. to 30 ° C. or the humidity is less than 70%, for example, it is determined that the door has not been opened even once, or a low load state such as a mild door opening / closing has continued. .

  If it is determined in step S2 that the outside air temperature is lower than 30 ° C. (No), the process proceeds to step S9. Moreover, when it determines with humidity being less than 70% in step S3 (No), it transfers to step S9.

  In step S9, it is determined whether the determination that the outside air temperature is 10 ° C. to 30 ° C. or the humidity is less than 70% has reached a preset second set time (for example, 100 hours). In step S9, when it reaches 100 hours (Yes), the process proceeds to step S10.

  In step S10, the above-described 30-minute precool operation is performed.

  When the precool operation for 30 minutes is completed, the defrost heater 35 is energized and the defrost operation is started (step S11).

  Subsequently, it is determined whether or not the temperature detected by the defrosting temperature sensor 39 has reached a predetermined second defrosting setting temperature (for example, 6 ° C.) for determining the end of defrosting (step S12). In step S12, the defrost heater 35 is heated until the detected temperature reaches 6 ° C., and the frost attached to the cooler 30 is continuously melted and removed.

  Thereafter, when the temperature detected by the defrosting temperature sensor 39 reaches 6 ° C., it is determined that the defrosting is sufficiently executed (Yes), the process proceeds to Step S13, the defrosting heater 35 is cut off, and the defrosting operation is performed. Exit. In the defrosting operation end step, the timer time built in the control unit 41 for integrating the operation time of the compressor 6 is cleared. And it returns to step S1 and repeats the control mentioned above.

  As described above, when the outside air temperature is lower than 10 ° C. or higher than 30 ° C., the humidity is higher than the preset humidity 70%, and the first set time reaches 24 hours, the first defrost set temperature is set. Defrosting was performed until the temperature reached 10 ° C. Further, when the second set time reaches 100 hours at an outside air temperature of 10 ° C. or more and 30 ° C. or less or less than 70%, defrosting is performed until the second defrost set temperature reaches 6 ° C.

  Therefore, when the outside air temperature is lower than 10 ° C. or higher than 30 ° C. and the humidity is higher than the preset humidity 70%, the defrosting temperature sensor 39 is set to 10 ° C. after 24 hours. Defrost until. In addition, when the outside air temperature is 10 ° C. or higher and 30 ° C. or lower or the load is lower than 70%, the defrosting is performed until the defrosting temperature sensor 39 reaches 6 ° C. after 100 hours. In short, in the case where the amount of defrosting is large, the defrosting operation interval is shortened and the defrosting temperature is increased. In the case where the amount of defrosting is small, the defrosting operation interval is lengthened and the defrosting temperature is lowered.

  In this embodiment, the determination temperature of the defrosting temperature sensor at the time of the defrosting operation at the low load when the frost amount is small is larger than the time when the frost amount is large than when the frost amount at the high load is large. A low temperature was set. As a result, the defrosting operation time at the time of low load with a small amount of frost formation can be shortened, and the energization rate to the defrosting heater can be suppressed compared to the defrosting operation at the time of high load with a large amount of frost formation to save energy. .

(Second Embodiment)
Next, a refrigerator according to a second embodiment will be described with reference to the flowchart of FIG. The same applies to the following embodiments.

  This embodiment relates to the defrosting control until the defrosting operation of the flowchart of FIG. 5 is started after the end of the previous defrosting operation. That is, after the previous defrosting operation is completed, until the next defrosting operation is started, the defrosting start determination is performed within a preset time, and the door is opened and closed during that time. When the increase width was equal to or less than a certain set value (for example, 3 ° C.), the defrosting end determination temperature was set to a low setting (for example, 6 ° C. as in Step S12).

  In this case, only at the time of a low load with a small amount of frost formation, the determination temperature of the defrost determination temperature sensor at the time of defrosting operation was set lower than that when the amount of frost formation was large. Thereby, defrost operation time can be shortened and the input added to a defrost heater can be suppressed rather than the defrost operation at the time of high load with much frost formation amount.

(Third embodiment)
A refrigerator according to the third embodiment will be described. In this embodiment, after the previous defrosting operation is completed, the defrosting start determination is performed within a preset time until the defrosting operation according to the flowchart of FIG. 5 is started. In the meantime, the door was opened and closed, and when the increase in the internal temperature was greater than a certain set value, the defrosting end determination temperature was set high.

  In this embodiment, only at the time of a high load with a large amount of frost formation, the determination temperature of the defrost determination temperature sensor at the time of the defrosting operation is set higher than that when the amount of frost formation is small. Thereby, sufficient defrost operation time can be ensured and deterioration of the cooling efficiency by the defrosting failure of a cooler can be prevented.

(Fourth embodiment)
A refrigerator according to the fourth embodiment will be described. The refrigerator 100 is in a state where the internal temperature is high when the power is turned on. In order to cool from the high internal temperature to the target temperature, the load of the cooler is larger than that during normal operation, and the amount of frost formation increases.

  Therefore, in this embodiment, in the first defrosting operation after turning on the power, the defrosting end determination temperature is set higher than the second defrosting setting temperature that is the defrosting end determination temperature at the time of low load. Thereby, even when the amount of frost formation at the time of the first defrosting is large, the defrosting can be completed reliably.

(Fifth embodiment)
A refrigerator according to a fifth embodiment will be described. In the refrigerator 100 when the outside air temperature is high, the load on the refrigeration cooler 30 is larger than that during normal operation in order to cool the inside of the refrigerator, and the amount of frost formation increases. For this defrosting, it is necessary to set a high defrosting end determination temperature during the defrosting operation.

  Therefore, in this embodiment, the detection value of the outside air temperature sensor 20 is added to the defrosting end determination temperature condition. Specifically, in a state where the outside air temperature is high (for example, 27 ° C. or higher), a temperature obtained by adding a predetermined temperature (for example, 1 ° C.) to the defrosting end determination temperature determined by the outside air temperature is removed as a new defrosting end determination temperature. Perform frost operation. Thereby, when the amount of frost formation of the refrigerating cooler 30 is large or small, the defrosting end determination temperature can be appropriately switched.

(Sixth embodiment)
A refrigerator according to a sixth embodiment will be described. When the outside air humidity is high, the refrigerator 100 has a higher amount of heat outside the box than when the humidity is low. The refrigerator 100 needs to set a higher defrosting end determination temperature during the defrosting operation because the load of the refrigeration cooler 27 is larger than when the humidity is low, the amount of frost formation increases, and the refrigerator 100 cools the inside of the refrigerator. is there.

  Therefore, in this embodiment, the value of the humidity sensor 21 is added to the defrosting end determination. Specifically, at a high outside air temperature (for example, 60% or more), a temperature obtained by adding a predetermined temperature (for example, 1 ° C.) to the defrosting end determination temperature determined by the outside air temperature is removed as a new defrosting end determination temperature. Perform frost operation. Thereby, when the amount of frost formation of the refrigerating cooler 30 is large or small, the defrosting end determination temperature can be appropriately switched.

  The first and second outside air set temperatures, the set humidity, the first and second set times, and the first and second defrost set temperatures specifically exemplified in the above embodiments are examples, and the capacity of the cooler And the capacity of the refrigerator.

  Although the defrosting of the refrigeration cooler 30 has been described, the refrigeration cooler 27 can also contribute to energy saving by performing the same defrosting operation. The cooler may be used for both refrigeration and freezing.

  Further, in steps S4 and S9 in FIG. 5, examples of simply counting the elapsed time are given. The accumulated time during which the compressor 6 is operated may be the first set time in step S4 and the second set time in step S9. When the accumulated time of the compressor 6 operation is the first set time and the second set time, defrosting can be performed in accordance with the operation rate of the compressor 6 as compared with a mere elapsed time, so that wasteful power consumption can be suppressed. it can.

  Although several embodiments have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, combinations, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

41 Control unit 411 Processor 412 Storage unit 42 Drive unit 19 Freezer temperature sensor 20 Outside air temperature sensor 21 Humidity sensor 27 Refrigeration cooler 30 Refrigeration cooler 39 Defrosting temperature sensor 6 Compressor 28 Refrigeration blower fan 35 Defrosting heater

Claims (9)

The outside air temperature sensor that detects the outside air temperature, the temperature sensor for defrost that detects the temperature of the cooler or the vicinity thereof, and the temperature detected by the temperature sensor for defrost reach the set temperature for determining the end of the defrost. And a controller that terminates the defrosting operation when the
The control unit determines whether the temperature detected by the defrosting temperature sensor is lower than a first set temperature or higher than a second set temperature higher than the first set temperature, and is lower than the first set temperature. If the temperature is higher than the second set temperature, the defrost operation is performed at the first defrost set temperature. If the temperature is between the first set temperature and the second set temperature, the first defrost is performed. A refrigerator that performs a defrosting operation at a second defrosting set temperature lower than the set temperature. In addition, it has a humidity sensor that detects the humidity of the outside air,
When the control unit is lower than the first set temperature or higher than the second set temperature and the humidity detected by the humidity sensor is higher than the set humidity, the controller performs the defrost operation at the first defrost set temperature. The defrosting operation is performed between the first set temperature and the second set temperature or when the humidity detected by the humidity sensor is lower than the set humidity. refrigerator.   The control unit presets the defrosting operation at the first defrosting set temperature after the first set time of the preset compressor operation or the defrosting operation at the second defrosting set temperature. The refrigerator according to claim 1 or 2, wherein the refrigerator is performed after the second set time of the compressor operation.   The refrigerator according to claim 3, wherein the second set time is longer than the first set time.   The refrigerator according to claim 3 or 4, wherein the first and second set times are set as an accumulated time of operation of the compressor.   The controller is configured to set the defrosting end determination temperature when the increase in the internal temperature in the period from the end of the previous defrosting operation to the start of the next defrosting operation is equal to or less than a set value. The refrigerator as described in any one of Claims 1 thru | or 5 which set low.   The refrigerator according to any one of claims 1 to 5, wherein the control unit sets a high set temperature for the defrosting end determination in the first defrosting operation after turning on the power.   The said control part set the preset temperature for the said defrost completion | finish determination in the first defrost operation after turning on a power supply and the subsequent defrost operation according to the value of the said external temperature sensor to be high or low. The refrigerator as described in any one of thru | or 5.   The control unit sets the set temperature for the defrosting end determination in the first defrosting operation after power-on and the subsequent defrosting operation to be high or low based on the humidity detected by the humidity sensor. Item 6. The refrigerator according to any one of Items 1 to 5.

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