JPH0979726A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve operation reliability of a compressor when a power source is closed and to shorten a time in which temperature in a refrigerator chamber during interruption to service is restored to a given temperature. SOLUTION: Right after making of a power source, energization to a compressor 4 and a blast fan 7 is started, and when a temperature DS of a room temperature sensor 14 and a temperature DF of a refrigerating chamber temperature sensor 9 are both higher than a set temperature Dmax, and when at a point of time when a given time ▵T1 elapses, further, a temperature DC of a condenser temperature sensor 23 exceeds an upper limit set value DCmax, a damper device 10 is forcibly closed a given time ▵T2 thereafter, ordinary control is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to reduction of load on a compressor in an indirect cooling type refrigerator.

[0002]

2. Description of the Related Art As a conventional control for reducing the load applied to a compressor in a refrigerator, for example, JP-A-5-240554 is known.

An example of a conventional refrigerator will be described below with reference to FIGS. 9, 10, 11 and 12.

FIG. 9 is a vertical sectional view of a conventional refrigerator, FIG. 10 is a block diagram showing a schematic electric configuration of the refrigerator, FIG. 11 is a control flowchart of the refrigerator, and FIG. 12 is a discharge side pressure of a compressor in the refrigerator. It is a change characteristic view.

In FIG. 9, a refrigerator main body 1 has a structure including a freezing compartment 2 and a refrigerating compartment 3, and doors (reference numerals 2a and 3a for doors for the freezing compartment 2 and the refrigerating compartment 3, respectively) are provided in the respective compartments. Is attached), and the compressor 4 is arranged at the lower part of the back surface thereof.

A cooling chamber 5 is formed on the rear surface of the freezing chamber 2, and a cooler 6, a blower fan 7 and a defrost heater 8 are installed in the cooling chamber 5, and a part of the freezing chamber 2 is provided. Is equipped with a freezer temperature sensor 9.

A damper device 1 is provided on the rear surface of the refrigerator compartment 3.
0 and temperature controller 11 with built-in cold room temperature sensor 11
2 is installed, the damper device 10 and the cooling chamber 5 are ducts 1
3 are connected. A room temperature sensor 14 is installed below the front surface of the freezer compartment door 3a.

In FIG. 10, the freezer compartment temperature sensor 9 generates a temperature detection signal according to the temperature of the freezer compartment 2, and the refrigerating compartment temperature sensor 11 generates a temperature detection signal according to the temperature of the refrigerating compartment 3 at room temperature. The sensor 14 is configured to generate a temperature detection signal according to the installation ambient temperature DS of the refrigerator body 1, and these temperature detection signals are given to the control circuit 15. The defrost timer 16 generates a defrost signal at every predetermined defrost cycle, and the defrost signal is given to the control circuit 15.

The control circuit 15 is composed of, for example, a microcomputer, and has a plug 17 connected to a commercial AC power source.
Is fed from the DC circuit 18 via the DC circuit 18. The control circuit 15 controls relays 19 to 22 to connect and disconnect the compressor 4, the blower fan 7, the damper device 10 and the defrost heater 8 on the basis of the input signals as described above and the control program stored in advance. Is configured to run through.

FIG. 11 shows only a part of the control by the control circuit 15 that is relevant to the gist of the present invention, which will be described below.

When the power is turned on, the compressor 4 and the blower fan 7 start operating (step S1), and in this state, the operation waits until a predetermined time ΔT1 elapses (step S2). When the time ΔT1 has elapsed, it is determined whether the temperature DS detected by the room temperature sensor 14 is equal to or higher than a predetermined upper limit temperature Dmax (step S3).

When the detected temperature DS is lower than the upper limit temperature Dmax, the normal control routine S7 is directly executed. When the detected temperature DS is higher than the upper limit temperature Dmax, that is, when the input load to the compressor 4 is reduced. Under the increasing condition, the blower fan 7 is stopped (step S4), and waits until the preset time ΔT2 has elapsed (step S5).

After the lapse of ΔT2, the power supply to the blower fan 7 is restarted (step S6), and then the normal control routine S7 is started.

The normal routine S7 is a very general one, and the operation of the compressor 4 and the blower fan 7 is controlled based on the temperature detection signal from the freezer compartment temperature sensor 9, and the temperature from the refrigerating compartment temperature sensor 11 is controlled. The opening / closing control of the damper device 10 is performed based on the detection signal, and the energization control of the defrost heater 8 is performed based on the defrost signal from the defrost timer 16.

The operation in such control is shown in FIG.
This will be described with reference to 2. When the refrigerator is transported in the summer and the power is turned on, the pressure on the discharge side of the compressor 4 sharply increases with time, and the load applied to the compressor 4 also increases in proportion to it.

After that, when ΔT1 has elapsed (discharge side pressure Pd1)
In addition, the detected temperature DS of the room temperature sensor 14 is the upper limit temperature Dma.
When it is equal to or more than x, the blower fan 7 is stopped for a time of ΔT2, and during this time, the heat exchange amount between the cooler 6 and the air in the cold storage decreases, and the discharge side pressure Pd of the compressor 4 also decreases, The input load on the compressor 4 also decreases.

However, during this time, since the operation of the compressor 4 is continued, the refrigerant continues to circulate in the cooling system, and the temperature of the cooler 6 decreases.

Thereafter, when the operation of the blower fan 7 is resumed after ΔT2 has elapsed, the discharge side pressure Pd of the compressor 4 is turned on while exhibiting a relatively low value because the temperature of the cooler 6 has sufficiently decreased. It rises in a gentler curve than at the time, shows the maximum value Pdmax, and then calms down to a value corresponding to the temperature of the cooler 6.
The increase in the input load to the output is also suppressed.

[0019]

However, in the above-mentioned structure, when the outside temperature is high (that is, when DS ≧ Dmax),
Even when a power failure occurs in a state where the freezer compartment 2 and the refrigerating compartment 3 are sufficiently cooled and the power is restored in a short time, the blower fan stops during ΔT2 after ΔT1 has passed, as in the case of turning on the power. As a result, it takes a long time for the freezer compartment 2 and the refrigerator compartment 3 to return to a predetermined temperature, which has a problem that the stored food is adversely affected.

In view of the above problems, the present invention aims at shortening the time required for the freezer compartment and the refrigerating compartment to return to a predetermined temperature after a power failure while ensuring the reliability of the compressor.

[0021]

In order to solve the above-mentioned problems, the refrigerator of the present invention has a condenser temperature sensor installed in a part of the high-pressure side pipe of the refrigeration cycle, and when the power is turned on, the freezer compartment temperature sensor and the room temperature. When both sensors detect the set temperature or more, or when both the refrigerating room temperature sensor and the room temperature sensor detect the set temperature or more, the condenser temperature sensor further detects the upper limit set temperature or more when a predetermined time has passed thereafter. Only in this case, the control means forcibly closing the damper device for a preset time is provided.

A means for detecting the power input value of the refrigerator body is provided, and when the power is turned on, when both the freezer compartment temperature sensor and the room temperature sensor detect a temperature higher than the set temperature, or both the refrigerating compartment temperature sensor and the room temperature sensor set the temperature. When the above is detected, only when the power input value detection means further detects the upper limit set value or more when a predetermined time has elapsed after that, a control means for forcibly closing the damper device for a preset time is provided. It was done.

[0023]

In the refrigerator of the present invention having the above-described structure, when the room temperature sensor and the freezer compartment temperature sensor or the refrigeration compartment temperature sensor both detect that the temperature is above the set temperature, that is, when the outside air temperature is high and uncooled, when the power is turned on. , After a lapse of a predetermined time, only when the condenser temperature sensor or the power input detection means is above the upper limit set value, that is, when the input load to the compressor is excessive, the damper device is forcibly closed for a preset time and goes to the refrigerating room. Since the supply of cold air is stopped, the load torque applied to the compressor is reduced, and when a power failure occurs in a sufficiently cooled state and the system returns in a short time, the freezer compartment temperature sensor and the refrigerator compartment temperature sensor Since the temperature is low and below the set temperature, the above control is not performed and the normal control remains.

Therefore, the time required for the freezing room and the refrigerating room to return to the predetermined temperature is not prolonged and the stored food is not adversely affected.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A refrigerator according to an embodiment of the present invention will be described below with reference to the drawings. The same components as those of the conventional example are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 is a front view of a machine room portion of the refrigerator of the present invention. Reference numeral 23 denotes a condenser temperature sensor, which is installed on a part of the high-pressure side pipe 25 in the refrigeration cycle by a locking tool 24 formed of a material having a high heat conductivity such as metal. Generates a temperature detection signal according to the temperature of.

FIG. 2 is a block diagram showing a schematic electric configuration of a refrigerator according to the first and second embodiments of the present invention.
FIG. 3 is a flowchart of control of the refrigerator according to the first embodiment of the present invention, and FIG. 4 is a flowchart of control of the refrigerator according to the second embodiment of the present invention.

In FIG. 2, the control circuit 26 is configured to include a microcomputer, and is configured to be supplied with power from a plug 17 connected to a commercial AC power source via a DC circuit 18, and a freezer compartment temperature sensor 9 , Cold room temperature sensor 1
1, the room temperature sensor 14, the defrost timer 16 and the condenser temperature sensor 23, the compressor 4,
The blower fan 7, the damper device 10, and the defrost heater 8 are energized to be controlled via relays 19 to 22.

FIG. 5 is a block diagram showing a schematic electric configuration of a refrigerator according to the third and fourth embodiments of the present invention.
FIG. 6 is a flowchart of control of the refrigerator in the third embodiment of the present invention, and FIG. 7 is a flowchart of control of the refrigerator in the fourth embodiment of the present invention.

In FIG. 5, reference numeral 27 is a power input detecting means, which generates a signal according to the power input value. The control circuit 28 is configured to include a microcomputer, and is configured to be supplied with power from a plug 17 connected to a commercial AC power source via a DC circuit 18, and includes a freezer compartment temperature sensor 9 and a refrigerating compartment temperature sensor 11. , The room temperature sensor 14, the defrost timer 16, and the power input detection means 27. Based on a control program stored in advance, the compressor 4, the blower fan 7, the damper device 10, and the defrost heater 8 are supplied with the input signals. The energization is configured to be controlled via the relays 19 to 22. FIG. 8 is a change characteristic diagram of the discharge side pressure of the compressor in the refrigerator of the present invention.

Regarding the refrigerator configured as described above,
The control will be described below. First, in the first embodiment, in FIGS. 2 and 3, when the power is turned on, the opening / closing control of the damper device 10 is started together with the operation start of the compressor 4 and the blower fan 7 (step P1), and immediately after that, the room temperature sensor 14 is started. It is determined whether both the detected temperature DS and the detected temperature DF of the freezer compartment temperature sensor 9 are equal to or higher than the set value Dmax (for example, 35 ° C.) (step P2).

When the detected temperatures DS and DF are both less than the set value Dmax, the normal control routine P8 is executed as it is, but when the detected temperatures DS and DF are both the set value Dmax or more, that is, high. When it is detected that the temperature is outside and the time is uncooled, the temperature DC detected by the condenser temperature sensor 23 is set to the upper limit set value DC after a lapse of a predetermined time ΔT1 (for example, 20 minutes) (step P3).
It is determined whether or not there is a maximum value (for example, 70 ° C.) or more (step P4).

Then, the detected temperature DC is the upper limit set value Dmax.
If it is less than the normal control routine P8
However, when the detected temperature DC is equal to or higher than the upper limit set value Dmax, that is, when the input load to the compressor 4 is excessive, the damper device 10 is forcibly closed (step P5) and preset. It waits until the time ΔT2 (for example, 45 minutes) has elapsed (step P6). Thereafter, after ΔT2 has elapsed, the opening / closing control of the damper device 10 is restarted (step P7), and then the normal control routine P8.
Move to.

2 and 4, in the second embodiment, when the power is turned on, the opening / closing control of the damper device 10 is started together with the start of the operation of the compressor 4 and the blower fan 7 (step P1). Immediately after the room temperature sensor 1
It is determined whether both the detected temperature DS of 4 and the detected temperature DP of the refrigerating compartment temperature sensor 11 are equal to or higher than the set value Dmax (for example, 35 ° C.) (P2-1).

When both the detected temperatures DS and DP are less than the set value Dmax, the normal control routine PS is executed as it is, but when the detected temperatures DS and DP are both the set value Dmax or more, that is, the high value. When it is detected that the temperature is outside and the time is uncooled, after a predetermined time ΔT1 (for example, 20 minutes) has elapsed (step P3),
The temperature DC detected by the condenser temperature sensor 23 is the upper limit set value D.
It is determined whether or not there is Cmax (for example, 70 ° C.) or more (step P4).

Then, the detected temperature DC is the upper limit set value Dmax.
If it is less than the normal control routine P8
However, when the detected temperature DC is equal to or higher than the upper limit set value Dmax, that is, when the input load to the compressor 4 is excessive, the damper device 10 is forcibly closed (step P5) and preset. It waits until the time ΔT2 (for example, 45 minutes) has elapsed (step P6). Thereafter, after ΔT2 has elapsed, the opening / closing control of the damper device 10 is restarted (step P7), and then the normal control routine P8.
Move to.

In the third embodiment, when the power is turned on in FIGS. 5 and 6, the opening / closing control of the damper device 10 is started together with the start of the operation of the compressor 4 and the blower fan 7 (step P1). Immediately after the room temperature sensor 1
4 detection temperature DS and freezer temperature sensor 9 detection temperature D
It is controlled whether both F are equal to or more than the set value Dmax (for example, 35 ° C.) (step P2).

When both the detected temperatures are less than the set value Dmax, the normal control routine P8 is executed as it is, but when the detected temperatures are both the set value Dmax or more, that is, when the outside air temperature is high, When it is detected that it is not cooled, a predetermined time ΔT1 (for example, 20 minutes)
After the elapse (step P3), it is determined whether or not the detection input value W of the power input detection means 27 is equal to or more than the upper limit set value Wmax (step P4-1).

Then, the detection input value W is the upper limit set value Wmax.
If it is less than the normal control routine P8
However, if the detected input value W is equal to or greater than the upper limit set value Wmax, that is, if the input load to the compressor 4 is excessive, the damper device 10 is forcibly closed (step P5) and preset. It waits until the lapsed time ΔT2 (for example, 45 minutes) elapses (step P6). Thereafter, after ΔT2 has elapsed, the opening / closing control of the damper device 10 is restarted (step P7), and then the normal control routine P8.
Move to.

Next, in the fourth embodiment, when the power is turned on in FIGS. 5 and 7, the opening / closing control of the damper device 10 is started together with the operation start of the compressor 4 and the blower fan 7 (step P1). Immediately after the room temperature sensor 1
It is determined whether both the detected temperature DS of 4 and the detected temperature DP of the refrigerating compartment temperature sensor 11 are equal to or higher than the set value Dmax (for example, 35 ° C.) (P2-1).

When both the detected temperatures DS and DP are less than the set value Dmax, the normal control routine P8 is executed as it is, but when the detected temperatures DS and DP are both the set value Dmax or more, that is, high. When it is detected that the temperature is outside and the time is uncooled, the detection input value W of the power supply input detecting means 27 is set to the upper limit set value Wma after a lapse of a predetermined time ΔT1 (for example, 20 minutes) (step P3).
It is determined whether x or more (step P4-1). Then, when the detected input value W is less than the upper limit set value Wmax, the normal control routine P8 is executed as it is, but when the detected input value W is not less than the upper limit set value Wmax, that is, the input load to the compressor 4 is increased. Under extreme circumstances,
The damper device 10 is forcibly closed (step P5),
The system waits until a preset time ΔT2 (for example, 45 minutes) elapses (step P6).

After a lapse of ΔT2, the damper device 1
The opening / closing control of 0 is restarted (step P7), and then the process proceeds to the normal control routine P8.

The operation of the above control will be described with reference to FIG. Under conditions where the refrigerator is transported and installed in the summer, that is, when the outside temperature is high and uncooled (DS ≧ Dm
ax and DF ≧ Dmax, or DS ≧ Dmax and D
In P ≧ Dmax), when the power is turned on, the discharge side pressure of the compressor 4 sharply rises with the passage of time, and the load applied to the compressor 4 also increases in proportion thereto.

Thereafter, when ΔT1 has elapsed (discharge-side pressure Pd1)
If the detected temperature DC of the condenser temperature sensor 23 is equal to or higher than the upper limit set value DCmax, or if the detected input value W of the power input detecting means 27 is equal to or higher than the upper limit set value Wmax, then only the time of ΔT2. Since the damper device 10 is closed and the supply of the cool air to the refrigerating chamber 3 is stopped, the heat exchange amount between the cooler 6 and the air in the cold storage is reduced during this period, and the discharge side pressure Pd of the compressor 4 is also lowered, which is naturally the compressor. The input load to 4 also decreases. However, during this time, the operation of the compressor 4 is continued, so that the refrigerant continues to circulate in the cooling system and the temperature of the cooler 6 decreases.

Thereafter, after the lapse of ΔT2, the damper device 10
Is returned to the normal opening / closing control and opened, and when the supply of the cool air to the refrigerating chamber 3 is restarted, the discharge side pressure Pd of the compressor 4 is
Since the temperature of the cooler 6 is sufficiently lowered, it rises in a gentle curve while exhibiting a relatively low value, and then rises to show the maximum value Pdmax, and then according to the temperature of the cooler 6. Compressor 4 began to settle down to the value
Stable operation will be performed in a controlled state even with an increase in the input load to the. After that, when a power failure occurs at time T3 and the energization is restarted at a time T4 for a very short time, the control circuit 26 recognizes that the power is turned on, but the freezer compartment 2 or the refrigerating compartment 3 is recognized.
Is higher than a predetermined temperature, but is in a cooled state, and both the detection temperature DF of the freezer compartment temperature sensor 9 and the detection temperature DP of the refrigerating compartment temperature sensor 11 are the upper limit set temperature D.
Since it is less than max, the subsequent control is performed according to the normal control. Therefore, in the conventional example, after the energization is restarted after the power failure, the blower fan 7 is stopped for the time T2 after the lapse of ΔT1 from the time point T4. However, in the present embodiment, the blower fan 7 is not stopped and is normally The operation will be continued according to the control.

In short, according to the configuration of this embodiment, the load applied to the compressor 4 is reduced at the time of high outside temperature and in the uncooled state, the reliability of the compressor 4 is ensured, and the power supply is restarted at the time of power failure. , Freezer 2 and refrigerator 3
The effect on stored food can be reduced without unnecessarily prolonging the time required for the internal temperature of the container to return to a predetermined temperature.

[0047]

As described above, according to the present invention, the condenser temperature sensor is installed in a part of the high-pressure side pipe of the refrigeration cycle, and when the power is turned on, both the freezer compartment temperature sensor and the room temperature sensor detect the temperature equal to or higher than the preset temperature. Or when both the refrigerating room temperature sensor and the room temperature sensor detect the set temperature or higher, and when the condenser temperature sensor detects the upper limit set temperature or higher at a predetermined time after that, only for a preset time. The damper means is forcibly closed, and the control means is provided to reduce the load on the compressor after the power is turned on and to ensure the reliability of the compressor when the ambient temperature is high and uncooled. At the same time, in the event of a power failure, after power is resumed, the freezing and refrigerating room temperatures can be saved without unnecessarily lengthening the time it takes to return to a specified temperature. The effect is obtained that to reduce the impact on the food.

Further, a means for detecting the power input value of the refrigerator body is provided, and when the power is turned on, when both the freezer compartment temperature sensor and the room temperature sensor detect a set temperature or higher, or both the refrigerating compartment temperature sensor and the room temperature sensor set temperature. When the above is detected, a control means for forcibly closing the damper device for a preset time is provided only when the power input value detection means further detects the upper limit set value or more after a predetermined time has elapsed. With the configuration, the accuracy of detecting the input load applied to the compressor after the power is turned on is improved, and the effect of more reliably executing the input load reduction control applied to the compressor is obtained.

[Brief description of drawings]

FIG. 1 is a front view of a machine room in a refrigerator according to the present invention.

FIG. 2 is a block diagram showing a schematic electric configuration of a refrigerator according to the first and second embodiments of the present invention.

FIG. 3 is a flowchart of a refrigerator control according to the first embodiment of the present invention.

FIG. 4 is a flowchart of a refrigerator control according to the second embodiment of the present invention.

FIG. 5 is a block diagram showing a schematic electric configuration of a refrigerator according to a third embodiment and a fourth embodiment of the present invention.

FIG. 6 is a flowchart of a refrigerator control according to the third embodiment of the present invention.

FIG. 7 is a flowchart of a refrigerator control according to a fourth embodiment of the present invention.

FIG. 8 is a change characteristic diagram of the discharge side pressure of the compressor in the refrigerator of the present invention.

FIG. 9 is a vertical sectional view of a conventional refrigerator.

FIG. 10 is a block diagram showing a schematic electric configuration of a conventional refrigerator.

FIG. 11 is a flowchart of control of a conventional refrigerator.

FIG. 12 is a change characteristic diagram of the discharge side pressure of the compressor in the conventional refrigerator.

[Explanation of symbols]

 2 Freezing room 3 Refrigerating room 4 Compressor 7 Blower fan 9 Freezing room temperature sensor 10 Damper device 11 Refrigerating room temperature sensor 14 Room temperature sensor 23 Condenser temperature sensor 26, 28 Control circuit 27 Power input detection means

Claims (4)

[Claims] 1. A freezer compartment, a refrigerator compartment, a compressor,
A condenser, a refrigeration cycle provided with a cooler, a blower fan for forcibly convection the cool air cooled by the cooler into the freezer compartment and the refrigerating compartment, a damper device for adjusting the amount of cool air discharged to the refrigerating compartment, A condenser temperature sensor that detects the temperature of the condenser, a freezer compartment temperature sensor that detects the temperature of the freezer compartment, a room temperature sensor that detects the outside air temperature, and means for controlling the opening and closing of the damper device, and a power supply When the temperature of the freezer compartment temperature sensor and the temperature of the room temperature sensor both detect the set temperature or more immediately after the power is turned on, and when the condenser temperature sensor temperature detects the upper limit set temperature or higher after a lapse of a predetermined time after the power is turned on, A refrigerator characterized in that the damper device is forcibly closed for a preset time. 2. A freezing room, a refrigerator room, a compressor,
A condenser, a refrigeration cycle provided with a cooler, a blower fan for forcibly convection the cool air cooled by the cooler into the freezer compartment and the refrigerating compartment, a damper device for adjusting the amount of cool air discharged to the refrigerating compartment, A condenser temperature sensor that detects the temperature of the condenser, a refrigerating compartment temperature sensor that detects the temperature of the refrigerating compartment, a room temperature sensor that detects the outside air temperature, and means for controlling the opening and closing of the damper device, and a power supply When both the temperature of the refrigerating room temperature sensor and the temperature of the room temperature sensor are both detected at a temperature higher than the set temperature immediately after the power is turned on, and after a predetermined time has passed after the power is turned on, the temperature of the condenser temperature sensor is detected at a temperature higher than the upper limit set temperature. A refrigerator characterized in that the damper device is forcibly closed for a preset time. 3. A freezer compartment, a refrigerator compartment, a compressor,
A refrigeration cycle including a condenser and a cooler, a blower fan for forcedly convection the cool air cooled by the cooler into the freezer compartment and the refrigerating compartment, a damper device for adjusting the amount of cold air discharged to the refrigerating compartment, and a refrigerator Power supply input detection means for detecting the power input of, a freezer compartment temperature sensor for detecting the temperature of the freezer compartment, a room temperature sensor for detecting the outside air temperature, and means for controlling the opening and closing of the damper device, Immediately after both the freezer compartment temperature sensor and the room temperature sensor detect a temperature equal to or higher than a preset temperature, if a predetermined time has elapsed after the power is turned on and the power input detecting means detects an upper preset value or higher, A refrigerator characterized in that the damper device is forcibly closed for a set time. 4. A refrigerator, a refrigerator, a compressor,
A refrigeration cycle including a condenser and a cooler, a blower fan for forcedly convection the cool air cooled by the cooler into the freezer compartment and the refrigerating compartment, a damper device for adjusting the amount of cold air discharged to the refrigerating compartment, and a refrigerator Power supply input means for detecting the power input of the refrigerator, a refrigerating compartment temperature sensor for detecting the temperature of the refrigerating compartment, a room temperature sensor for detecting the outside air temperature, and a means for controlling the opening and closing of the damper device, Immediately after that, when both the temperature of the refrigerating room temperature sensor and the temperature of the room temperature sensor are above the set temperature, if the power input detecting means detects the upper limit set value or more after a lapse of a predetermined time after turning on the power, A refrigerator characterized in that the damper device is forcibly closed for a set time.