JP2023019909A - refrigerator - Google Patents

Abstract

To provide a refrigerator which can effectively keep a small cold room at low temperature and constant temperature.SOLUTION: A refrigerator 10 of the invention includes: a cold room 12; a small cold room 20 defined in the cold room 12; a small cold room temperature sensor 22 which measures an in-room temperature of the small cold room 20; a cooling room 115 in which air blown to the small cold room 20 is cooled by a cooler; a heating part 117 configured to defrost the cooler by heating; a blower 25 which blows air from the cooling room 115 to the cold room 12; and a calculation control unit 26. Further, the calculation control unit 26 executes a cooling cycle in which the cooler and the blower 25 are operated so that the in-room temperature of the small cold room 20 measured by the small cold room temperature sensor 22 is lower than or equal to a first upper limit temperature and higher than or equal to a first lower limit temperature and decreases the first lower limit temperature in the cooling cycle immediately before a defrosting operation.SELECTED DRAWING: Figure 3

Description

TECHNICAL FIELD The present invention relates to a refrigerator, and more particularly to a refrigerator having a small refrigerator compartment inside the refrigerator compartment.

2. Description of the Related Art Conventionally, there has been known a refrigerator in which a storage container is arranged inside a refrigerator compartment, such as that described in Patent Document 1. Here, the chilled container is accommodated in the lowest part of the refrigerating compartment. The air blown by the blower is supplied to the refrigerating compartment via the air duct formed on the rear side of the refrigerating compartment. Air is blown into the chilled container, and cold air is directly supplied to the stored object such as meat. By doing so, the internal temperature of the chilled container is made lower than the internal temperature of the refrigerator compartment, for example, about 0.degree. Therefore, food such as meat stored in the chilled container can be preserved.

JP 2018-44687 A

However, the refrigerator described in Patent Document 1 mentioned above has room for improvement in terms of lowering the temperature of the small refrigerating compartment and achieving a constant temperature.

This problem will be described in detail with reference to the graph of FIG. In this graph, the horizontal axis indicates the passage of time, and the vertical axis indicates temperature. Further, the internal temperature of the refrigerator compartment is indicated by a solid line, the internal temperature of the chilled compartment is indicated by a dotted line, and the internal temperature of the freezer compartment is indicated by a dashed line. Referring to this graph, the internal temperatures of all the storage compartments are rising during the defrosting process. The reason for this is that, in the defrosting process, cooling is not performed by the evaporator, and the temperature inside the cooling chamber is raised by the defrosting heater. In this case, if the internal temperature of the chilled compartment becomes 0° C. or higher, the meat or fish stored in the chilled compartment will temporarily melt, resulting in a problem of reduced freshness.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a refrigerator capable of effectively achieving low temperature and constant temperature in a small refrigerator compartment.

The refrigerator of the present invention includes a refrigerating chamber, a small refrigerating chamber partitioned inside the refrigerating chamber, a small refrigerating chamber temperature sensor for measuring the internal temperature of the small refrigerating chamber, and blowing air to the small refrigerating chamber. a cooling chamber that cools air with a cooler; a heating unit that defrosts the cooler by heating; a blower that blows the air from the cooling chamber to the refrigerating chamber; Arithmetic control unit
A cooling cycle is executed to operate the cooler and the blower so that the internal temperature of the small refrigerating chamber measured by the small refrigerating chamber temperature sensor is equal to or lower than a first upper limit temperature and equal to or higher than a first lower limit temperature. The set value of the first lower limit temperature is lowered in the cooling cycle immediately before the defrosting operation.

Further, the refrigerator of the present invention further includes a freezer compartment and a freezer compartment temperature sensor that measures the internal temperature of the freezer compartment, and the arithmetic control unit controls the temperature of the freezer compartment measured by the freezer compartment temperature sensor. The freezer compartment is cooled so that the temperature inside the freezer is equal to or lower than the second upper limit temperature and equal to or higher than the second lower limit temperature, and in the cooling cycle immediately before the defrosting operation, the freezer compartment temperature sensor measures When the temperature inside the freezer compartment measured by the temperature sensor is equal to or lower than the second lower limit temperature and the temperature inside the small refrigerator compartment measured by the small refrigerator compartment temperature sensor is lower than or equal to the first lower limit temperature, It is characterized by executing frost operation.

Further, the refrigerator of the present invention further includes a damper provided in an air passage connecting the cooling chamber and the small refrigerator chamber, and the arithmetic control unit operates the damper before executing the defrosting operation. The fan is operated in an open state.

Further, in the refrigerator of the present invention, a mode for preferentially cooling the small refrigerating chambers can be selected, and when the mode for preferentially cooling the small refrigerating chambers is selected, the arithmetic control unit The set value of the first lower limit temperature is lowered in the cooling cycle immediately before the defrosting operation.

The refrigerator of the present invention includes a refrigerating chamber, a small refrigerating chamber partitioned inside the refrigerating chamber, a small refrigerating chamber temperature sensor for measuring the internal temperature of the small refrigerating chamber, and blowing air to the small refrigerating chamber. a cooling chamber that cools air with a cooler; a heating unit that defrosts the cooler by heating; a blower that blows the air from the cooling chamber to the refrigerating chamber; Arithmetic control unit
A cooling cycle is executed to operate the cooler and the blower so that the internal temperature of the small refrigerating chamber measured by the small refrigerating chamber temperature sensor is equal to or lower than a first upper limit temperature and equal to or higher than a first lower limit temperature. Further, in the cooling cycle immediately before the defrosting operation, the set value of the first lower limit temperature is lowered. According to the refrigerator of the present invention, it is possible to effectively achieve low temperature and constant temperature in the small refrigerator compartment. Specifically, by lowering the minimum temperature in the cooling cycle immediately before the defrosting operation, it is possible to lower the internal temperature of the small refrigerator compartment immediately before the defrosting operation. Therefore, even if the temperature of the refrigerating compartment rises due to the defrosting operation, the temperature inside the small refrigerating compartment can be prevented from rising excessively, and the freshness of the food stored in the small refrigerating compartment can be maintained.

Further, the refrigerator of the present invention further includes a freezer compartment and a freezer compartment temperature sensor that measures the internal temperature of the freezer compartment, and the arithmetic control unit controls the temperature of the freezer compartment measured by the freezer compartment temperature sensor. The freezer compartment is cooled so that the temperature inside the freezer is equal to or lower than the second upper limit temperature and equal to or higher than the second lower limit temperature, and in the cooling cycle immediately before the defrosting operation, the freezer compartment temperature sensor measures When the temperature inside the freezer compartment measured by the temperature sensor is equal to or lower than the second lower limit temperature and the temperature inside the small refrigerator compartment measured by the small refrigerator compartment temperature sensor is lower than or equal to the first lower limit temperature, It is characterized by executing frost operation. According to the refrigerator of the present invention, when the freezing compartment is at or below the second lower limit temperature and both the small refrigerator compartments are at or below the first lower limit temperature, the defrosting operation is started. It is possible to prevent the temperature from rising above a certain level.

Further, the refrigerator of the present invention further includes a damper provided in an air passage connecting the cooling chamber and the small refrigerator chamber, and the arithmetic control unit operates the damper before executing the defrosting operation. The fan is operated in an open state. According to the refrigerator of the present invention, the air blower is operated with the damper in an open state before executing the defrosting operation, thereby further cooling the small refrigerating chamber and increasing the internal temperature of the small refrigerating chamber during the defrosting operation. can suppress the increase in

Further, in the refrigerator of the present invention, a mode for preferentially cooling the small refrigerating chambers can be selected, and when the mode for preferentially cooling the small refrigerating chambers is selected, the arithmetic control unit The set value of the first lower limit temperature is lowered in the cooling cycle immediately before the defrosting operation. According to the refrigerator of the present invention, when the user selects a mode in which the small refrigerator compartment is preferentially cooled, the lower limit temperature is lowered in the cooling cycle immediately before the defrosting operation. The small refrigerating compartment can be cooled appropriately, and the energy required for cooling can be reduced.

It is a side cross-sectional view showing the internal configuration of the refrigerator according to the embodiment of the present invention. It is a block diagram which shows the connection structure of the refrigerator which concerns on embodiment of this invention. It is a flowchart which shows the cooling method of the refrigerator which concerns on embodiment of this invention. It is a graph which shows the temperature change of the refrigerator which concerns on embodiment of this invention. It is a graph which shows the temperature change of the refrigerator based on background art.

Hereinafter, refrigerator 10 concerning an embodiment of the present invention is explained in detail based on a drawing. In the description of the present embodiment, in principle, the same reference numerals are used for the same members, and repeated descriptions are omitted.

FIG. 1 is a side sectional view of refrigerator 10 .

The heat-insulating box body 11 constituting the main body of the refrigerator 10 includes an outer box 111 made of steel plate bent into a predetermined shape, an inner box 112 made of a synthetic resin plate arranged inside and separated from the outer box 111, It is composed of a heat insulating material 113 filled between the outer box 111 and the inner box 112 .

The refrigerating compartment inside the heat-insulating box 11 is divided into a refrigerating compartment 12 and a freezing compartment 13 from above. The refrigerator compartment 12 and the freezer compartment 13 are separated by a heat insulating wall 17 . The front opening of the refrigerating compartment 12 is closed with an insulating door 18, and the front opening of the freezing compartment 13 is closed with an insulating door 19. - 特許庁

The small refrigerating compartment 20 is a refrigerating compartment that is separated from the other area of the refrigerating compartment 12 in the lower part of the refrigerating compartment 12 . The small refrigerating compartment 20 is a chilled compartment whose interior is cooled to a lower temperature, for example, about -3° C. than the other regions of the refrigerating compartment 12 . The small refrigerator compartment 20 is formed inside a storage container 21 made of synthetic resin and having an open upper surface. The storage container 21 is arranged so that it can be pulled out forward. Inside the small refrigerating compartment 20, an object to be stored 23, such as meat or fish, is stored in a semi-frozen state.

Cooling chamber 115 is formed on the far side of freezing chamber 13 . Inside the cooling chamber 115, an evaporator 116, which is a cooler, is arranged. A machine room 14 is defined behind the lower end of the refrigerator 10 , and a compressor 15 is arranged in the machine room 14 . Evaporator 116 and compressor 15 together with a condenser and expansion means not shown here form a vapor compression refrigeration cycle. By operating the vapor compression refrigeration cycle, the air inside the cooling chamber 115 is cooled by the evaporator 116, and this air is blown into each refrigerating chamber, so that the internal temperature of each refrigerating chamber is kept within a predetermined cooling temperature range. becomes.

The blower 25 is arranged above the evaporator 116 inside the cooling chamber 115 . Blower 25 is an axial blower or a centrifugal blower, and blows the air inside evaporator 116 cooled by evaporator 116 toward refrigerator compartment 12 and freezer compartment 13 .

The heating unit 117 is arranged inside the evaporator 116 and below the evaporator 116 . The heating unit 117 is, for example, a heater that generates heat when energized.

The air passage 118 is formed upward from the cooling chamber 115 . An air outlet 16 that is an opening for blowing air into the refrigerating compartment 12 is formed in the upper portion of the air duct 118 . Part of the air cooled by evaporator 116 is also sent to freezer compartment 13 . Furthermore, part of the air cooled by the evaporator 116 is also sent to the interior of the small refrigerator compartment 20 via the air passage 118 and the blower outlet 30 .

The damper 28 is opening/closing means interposed in the blowing path 118 . By opening damper 28 , air can be blown from cooling compartment 115 to refrigerating compartment 12 and small refrigerating compartment 20 . On the other hand, the blowing passage 118 is closed by closing the damper 28 . Damper 28 is a multi-damper that can individually open and close both air passage 118 leading to refrigerator compartment 12 and air passage 118 leading to small refrigerator compartment 20 .

The small refrigerator compartment temperature sensor 22 is a sensor that measures the internal temperature of the small refrigerator compartment 20 . The freezer compartment temperature sensor 27 is a sensor that measures the internal temperature of the freezer compartment 13 . Defrost sensor 29 is a temperature sensor located inside cooling chamber 115 and near evaporator 116 . As will be described later, the defrost sensor 29 is used in the defrosting process of defrosting the evaporator 116 .

FIG. 2 is a block diagram showing a connection configuration of refrigerator 10. As shown in FIG.

The arithmetic control unit 26 is composed of a CPU, RAM, ROM, etc., executes predetermined arithmetic processing based on information input from the input side terminal, and outputs an output signal generated by this processing from the output terminal side. Input terminals of the arithmetic control unit 26 are connected to the small refrigerator compartment temperature sensor 22 , the freezer compartment temperature sensor 27 , the timer 24 and the defrosting sensor 29 . Compressor 15 , blower 25 and heating unit 117 are connected to output terminals of arithmetic control unit 26 .

The small refrigerating compartment temperature sensor 22 measures the internal temperature of the small refrigerating compartment 20 described above, and inputs information indicating this temperature to the arithmetic control section 26 .

The freezer compartment temperature sensor 27 measures the internal temperature of the freezer compartment 13 described above, and inputs information indicating this temperature to the arithmetic control unit 26 .

The timer 24 measures time or time and inputs information indicating these to the arithmetic control unit 26 .

The defrosting sensor 29 measures the internal temperature of the cooling chamber 115 during the defrosting process, and inputs information indicating this temperature to the arithmetic control unit 26, as will be described later.

The compressor 15 compresses the refrigerant used in the above-described refrigeration cycle based on information output from the arithmetic control unit 26 .

Blower 25 blows the air in cooling chamber 115 to refrigerating chamber 12 and freezing chamber 13 based on information output from arithmetic control unit 26 .

The heating unit 117 generates heat based on the information output from the arithmetic control unit 26 to raise the temperature inside the cooling chamber 115 and defrost the frost adhered to the evaporator 116 .

The basic operation of the refrigerator 10 having the configuration described above will be described below.

When the cooling operation is performed, the arithmetic control unit 26 cools the air inside the cooling chamber 115 with the evaporator 116 by operating the compressor 15 . Further, the arithmetic control unit 26 blows the air inside the cooling chamber 115 by operating the blower 25 . The blown air is blown into refrigerating compartment 12 via air duct 118 and air blowing port 16 , thereby cooling the inside of refrigerating compartment 12 . A part of the blown air is also blown into the inside of the small refrigerating compartment 20, whereby the inside of the small refrigerating compartment 20 is also cooled. Furthermore, part of the blown air is blown to the freezer compartment 13, whereby the inside of the freezer compartment 13 is also cooled to a predetermined freezing temperature zone. Also, the air that has cooled each storage compartment returns to the cooling compartment 115 via a return air passage (not shown).

The cooling operation is performed so that the internal temperature of the freezer compartment 13 is within a predetermined temperature range. Specifically, when the internal temperature of the freezer compartment 13 detected by the freezer compartment temperature sensor 27 reaches the upper limit temperature (second upper limit temperature) or higher, the arithmetic control unit 26 operates the compressor 15 and the blower 25. Then, the inside of the freezer compartment 13 is cooled. After that, when the internal temperature of the freezer compartment 13 detected by the freezer compartment temperature sensor 27 reaches the lower limit temperature (second lower limit temperature) or lower, the arithmetic control unit 26 stops the compressor 15 and the blower 25, and the freezer compartment 13 stop cooling. For example, the freezer compartment 13 has an upper limit temperature of -18°C and a lower limit temperature of -22°C. Here, the upper limit temperature is called the ON point and the lower limit temperature is also called the OFF point.

A process from the start and stop of the operation of the compressor 15 and the blower 25 to the start of the next operation is called one refrigeration cycle.

The temperature of the small refrigerator compartment 20 is similarly controlled so that the internal temperature is within a predetermined temperature range. Specifically, when the internal temperature of the small refrigerating chamber 20 detected by the small refrigerating chamber temperature sensor 22 reaches the upper limit temperature (first upper limit temperature) or higher, the arithmetic control unit 26 Air from the cooling chamber 115 is introduced inside. Further, when the internal temperature of the small refrigerator compartment 20 reaches the lower limit temperature (first lower limit temperature) or lower, the arithmetic control unit 26 stops cooling the small refrigerator compartment 20 . For example, the upper limit temperature of the small refrigerator compartment 20 is -2°C, and the lower limit temperature is -4°C.

Furthermore, the arithmetic control unit 26 similarly controls the temperature of the refrigerator compartment 12 so that the temperature inside the refrigerator compartment is in a predetermined temperature range, for example, +2° C. or higher and +5° C. or lower.

The defrosting operation is an operation for melting frost adhering to the surface of the evaporator 116 . Specifically, when the vapor compression refrigeration cycle is operated, thick frost forms on the surface of the evaporator 116, and if the cooling operation is continued in this state, the frost hinders heat transfer and ventilation. For this reason, in the defrosting operation, the arithmetic control unit 26 stops the compressor 15 and the blower 25, closes the damper 28, and energizes the heating unit 117 to heat it, thereby melting and removing the frost. do the driving.

With reference to the flow chart of FIG. 3, a method of performing a defrosting operation while suppressing an increase in the temperature inside the small refrigerator compartment 20 when the user selects the "freshness keeping chilled mode" will be described.

At step S10, the arithmetic control unit 26 is executing a normal cooling operation. That is, as described above, the arithmetic control unit 26 controls the compressor 15 and the The air blower 25 is operated.

In step S11, the operation control unit 26 executes the freshness preservation chilled mode by the user operating an operation panel (not shown). In the freshness keeping chilled mode, as will be described later, the inside temperature of the small refrigerator compartment 20 is lowered more than in the normal cooling cycle before executing the defrosting process. Therefore, the internal temperature of the small refrigerating compartment 20 can be prevented from reaching 0° C. or higher during the defrosting process, and the freshness of the stored items 23 stored in the small refrigerating compartment 20 can be maintained satisfactorily.

In step S12, the arithmetic control unit 26 lowers the lower limit temperature of the small refrigerating chamber temperature sensor 22 of the small refrigerating chamber 20 by, for example, 2° C. cooling.

Here, normal operation is operation in which a mode such as the freshness keeping chilled mode is not selected. In normal operation, the arithmetic control unit 26 cools the inside temperature of the small storage compartment 20 to about 0 degrees, for example, in order to reduce the energy consumption and save the electricity bill. On the other hand, in the freshness keeping chilled mode, the arithmetic control unit 26 lowers the lower limit temperature to about -3°C.

In step S13, the arithmetic control unit 26 starts the defrosting control in the freshness keeping chilled mode after the cumulative operation time of the compressor 15 has passed a predetermined time.

In step S<b>14 , the arithmetic control unit 26 uses the timer 24 to check whether or not the cumulative operating time of the compressor 15 has reached a predetermined time. Here, the predetermined time is the time required for defrosting in the evaporator 116, for example, 88 hours.

If YES in step S14, that is, if the cumulative operating time of the compressor 15 has reached the predetermined time, the arithmetic control unit 26 proceeds to step S15.

If NO in step S14, that is, if the cumulative operating time of the compressor 15 has not reached the predetermined time, the arithmetic control unit 26 returns to step S13.

In step S15, the arithmetic control unit 26 determines whether the internal temperature of the freezer compartment 13 measured by the freezer compartment temperature sensor 27 has reached the freezer compartment lower limit temperature (second lower limit temperature) or less. Here, the freezer compartment lower limit temperature is, for example, -22°C.

In the case of YES in step S15, that is, if the internal temperature of the freezer compartment 13 has reached the lower limit temperature of the freezer compartment or less, the arithmetic control unit 26 proceeds to step S16.

In the case of NO in step S15, that is, if the internal temperature of the freezer compartment 13 has not reached the lower limit temperature of the freezer compartment or less, the arithmetic control unit 26 returns to step S13.

In step S16, the arithmetic control unit 26 further cools the inside of the small storage compartment 20 in the cooling cycle immediately before the defrosting operation. Specifically, the arithmetic control unit 26 determines whether or not the internal temperature of the small refrigerator compartment 20 measured by the freezer compartment temperature sensor 27 has reached the lower limit temperature (first lower limit temperature) of the small storage compartment or less. do. Here, the small storage compartment lower limit temperature is, for example, −4° C., which is even lower than the small storage compartment lower limit temperature in the normal freshness keeping chilled mode.

If YES in step S16, that is, if the internal temperature of the small refrigerator compartment 20 has reached the lower limit temperature of the small storage compartment or less, the small refrigerator compartment 20 is sufficiently cooled, so the arithmetic control unit 26 , the process proceeds to step S17.

If NO in step S16, that is, if the internal temperature of the small refrigerator compartment 20 has not reached the lower limit temperature of the small storage compartment or less, the arithmetic control unit 26 returns to step S13.

In step S<b>17 , the arithmetic control unit 26 stops the cooling of the cooling chamber 115 by the evaporator 116 by stopping the compressor 15 .

In step S18, after stopping the compressor 15, the arithmetic control unit 26 puts the damper 28 in a state of blowing air only to the small refrigerator compartment 20, and operates the blower 25 for a predetermined time. By doing so, it is possible to supply cold air only to the interior of the small refrigerating chamber 20 prior to the defrosting process, thereby further lowering the internal temperature of the small refrigerating chamber 20 .

In step S<b>19 , the arithmetic control unit 26 stops the blower 25 and closes the damper 28 . By closing the damper 28, it is possible to prevent warm air warmed by the heating unit 117 from entering the small refrigerating compartment 20 and the refrigerating compartment 12 in the defrosting operation.

At step S20, the arithmetic control unit 26 starts the defrosting process. Specifically, the arithmetic control unit 26 energizes the heating unit 117 to raise the temperature inside the cooling chamber 115 and melt the frost adhering to the evaporator 116 .

In step S21, the arithmetic control unit 26 determines whether the temperature detected by the defrost sensor 29 has reached the upper limit temperature.

If YES in step S21, that is, if the temperature detected by the defrosting sensor 29 reaches the upper limit temperature, the arithmetic control unit 26 proceeds to step S22. That is, the power supply to the heating portion 117 is stopped.

If NO in step S21, that is, if the temperature detected by the defrost sensor 29 has not reached the upper limit temperature, the arithmetic control unit 26 proceeds to step S20.

In step S<b>22 , the arithmetic control unit 26 waits until the safety time of about several minutes has passed, then operates the compressor 15 and cools the air inside the cooling chamber 115 with the evaporator 116 .

In step S<b>23 , the arithmetic control unit 26 operates the blower 25 and opens the damper 28 . By doing so, the air inside the cooling compartment 115 cooled by the evaporator 116 is sent to the refrigerating compartment 12 , the freezing compartment 13 and the small refrigerating compartment 20 .

In step S24, the arithmetic control unit 26 ends the defrosting process and returns to the normal cooling operation or the freshness keeping chilled mode.

The above is the description of the defrosting operation of the refrigerator 10 according to the present embodiment.

With reference to the graph of FIG. 4, temperature changes in the small refrigerator compartment 20 and the like during the operation of the refrigerator 10 described above will be described. The horizontal axis of this graph indicates the elapsed time, and the vertical axis indicates the internal temperature. Furthermore, in this graph, the internal temperature of the refrigerator compartment 12 is indicated by a solid line, the internal temperature of the small refrigerator compartment 20 is indicated by a dotted line, and the internal temperature of the freezer compartment 13 is indicated by a dashed line.

Referring to this graph, in the cooling cycle immediately before the defrosting process, the internal temperature of small refrigerator compartment 20 is lowered to -5°C. Such temperature reduction is performed by lowering the lower limit temperature in step S12 described above.

Further, in the defrosting process, the freezing cycle is stopped and heating is performed by the heating unit 117, so the internal temperatures of the refrigerating chamber 12, the small refrigerating chamber 20 and the freezing chamber 13 gradually rise. . However, since the internal temperature of the small refrigerating chamber 20 is lowered prior to the defrosting process, the maximum temperature of the small refrigerating chamber 20 is about -1°C, and the internal temperature of the small refrigerating chamber 20 is 0. °C cannot be exceeded. Therefore, the objects to be stored 23 stored in the small refrigerator compartment 20 are not melted, and the freshness of the objects can be maintained satisfactorily.

According to this embodiment, the main effects described below can be obtained.

That is, by lowering the minimum temperature in the cooling cycle immediately before the defrosting operation, the inside temperature of the small refrigerator compartment 20 immediately before the defrosting operation can be lowered. Therefore, even if the temperature of the refrigerating compartment 12 rises due to the defrosting operation, the internal temperature of the small refrigerating compartment 20 can be suppressed from rising to 0° C. or higher, and the freshness of the food stored in the small refrigerating compartment 20 can be maintained. can. For example, according to the present embodiment, the internal temperature of the small refrigerating compartment 20 can be set within the range of -2°C to -4°C, and the objects to be stored in the small refrigerating compartment 20 are stored in a semi-frozen state. 23 freshness can be maintained for 10 days or more, as an example.

Moreover, when the freezer compartment 13 is below the minimum temperature and both the small refrigerator compartments 20 are below the minimum temperature, a defrosting operation is started. Specifically, immediately before defrosting, the arithmetic control unit 26 reduces the internal temperature of the freezer compartment 13 and the small refrigerator compartment 20 to the lower limit temperature, and then stops the compressor 15 to perform the defrosting operation. Therefore, in the defrosting operation, it is possible to prevent the internal temperature of the small refrigerator compartment 20 from rising above a certain level.

Furthermore, before executing the defrosting operation, the air blower 25 is operated with the dampers of the small refrigerating chambers 20 in an open state, thereby further cooling the small refrigerating chambers 20 and reducing the internal temperature of the small refrigerating chambers 20 during the defrosting operation. Temperature rise can be suppressed.

Furthermore, when the user selects a mode in which the small refrigerator compartment 20 is preferentially cooled, the lower limit temperature is lowered in the cooling cycle immediately before the defrosting operation, thereby making the small refrigerator compartment 20 suitable for the user's request. and the energy required for cooling can be reduced.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. Moreover, each form described above can be combined with each other.

10 Refrigerator 11 Insulation box body 111 Outer box 112 Inner box 113 Insulation material 115 Cooling room 116 Evaporator 117 Heating part 118 Air passage 12 Refrigerator room 13 Freezer room 14 Machine room 15 Compressor 16 Air outlet 17 Insulation wall 18 Insulation door 19 Insulation Door 20 Small refrigerator compartment 21 Storage container 22 Small refrigerator compartment temperature sensor 23 Object to be stored 24 Timer 25 Blower 26 Calculation control unit 27 Freezer compartment temperature sensor 28 Damper 29 Defrost sensor

Claims (4)

a refrigerator and
a small refrigerating compartment partitioned inside the refrigerating compartment;
a small refrigerator compartment temperature sensor for measuring the internal temperature of the small refrigerator compartment;
a cooling chamber for cooling the air blown into the small refrigerating chamber with a cooler;
a heating unit that defrosts the cooler by heating;
a blower that blows the air from the cooling chamber to the refrigerating chamber;
and an arithmetic control unit,
The arithmetic control unit is
A cooling cycle is executed to operate the cooler and the blower so that the internal temperature of the small refrigerating chamber measured by the small refrigerating chamber temperature sensor is equal to or lower than a first upper limit temperature and equal to or higher than a first lower limit temperature. death,
A refrigerator, wherein the set value of the first lower limit temperature is lowered in the cooling cycle immediately before the defrosting operation. a freezer compartment;
a freezer compartment temperature sensor that measures the internal temperature of the freezer compartment,
The arithmetic control unit is
cooling the freezer compartment so that the internal temperature of the freezer compartment measured by the freezer compartment temperature sensor is equal to or lower than a second upper limit temperature and equal to or higher than a second lower limit temperature;
In the cooling cycle immediately before the defrosting operation, the internal temperature of the freezer compartment measured by the freezer compartment temperature sensor is equal to or lower than the second lower limit temperature, and the small refrigerator compartment temperature measured by the small refrigerator compartment temperature sensor 2. The refrigerator according to claim 1, wherein the defrosting operation is performed when the internal temperature of the refrigerator compartment is equal to or lower than the first lower limit temperature. further comprising a damper provided in an air passage connecting the cooling chamber and the small refrigerating chamber;
3. The refrigerator according to claim 1, wherein said arithmetic control unit operates said blower with said damper opened before executing said defrosting operation. configured to be able to select a mode for preferentially cooling the small refrigerating compartment,
The arithmetic control unit lowers the set value of the first lower limit temperature in the cooling cycle immediately before the defrosting operation when a mode for preferentially cooling the small refrigerator compartment is selected. The refrigerator according to any one of claims 1 to 3.

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