Refrigerator and control device

Abstract

This refrigerator comprises: a cooler which cools air by performing heat exchange between the air and a refrigerant flowing inside; a main body that has a storage chamber which stores a stored object, and a cooler chamber in which the cooler is provided; a blower that sends air to the storage chamber; a compressor that compresses the refrigerant; a heater that heats the cooler; and a control device that controls the compressor, the blower, and the heater, wherein the control device sequentially executes a temperature adjustment operation for controlling the compressor and the blower to adjust the temperature of the storage chamber to a set temperature, a pre-cooling operation for controlling the compressor and the blower to adjust the temperature of the storage chamber to a pre-cooling set temperature which is lower than the set temperature, and a defrosting operation for controlling the heater to remove frost adhering to the cooler, and changes, on the basis of an estimated frost amount of the cooler before the defrosting operation is started, at least one of the rotation speed of the compressor, the rotation speed of the blower, and the pre-cooling set temperature in the pre-cooling operation.

Description

Refrigerator and control device

[0001] The present disclosure relates to a refrigerator and a control device that calculates the amount of frost formed in a cooler of the refrigerator.

[0002] Refrigerators maintain a low temperature in the storage compartment by sending air that has exchanged heat with a low-temperature refrigerant in a cooler to the storage compartment using a fan. The air returning from the storage compartment to the cooler compartment where the cooler is installed is relatively hot and contains water vapor. As a result, frost forms on the surface of the cooler when heat is exchanged between the air and the refrigerant. The buildup of frost on the cooler reduces the efficiency of heat exchange, making it difficult to cool the storage compartment. It also increases the refrigerator's power consumption. Therefore, a defrosting operation is commonly performed, in which the cooler is heated by a heater to melt the frost.

[0003] On the other hand, during defrosting operation, the cooler is heated by the heater, so the storage compartment cannot be cooled. Therefore, the temperature inside the storage compartment rises due to heat from outside the refrigerator and heat from the heater that enters the storage compartment. When the temperature inside the storage compartment rises, moisture contained in food in the storage compartment evaporates, accelerating food deterioration. Therefore, in order to prevent frost formation and improve food shelf life, refrigerators are known that perform a pre-cooling operation immediately before defrosting, lowering the storage compartment's set temperature below the set temperature during normal operation (see, for example, Patent Document 1). The refrigerator in Patent Document 1 changes the pre-cooling operation time based on the estimated amount of frost that has formed on the cooler.

[0004] Japanese Patent Application Publication No. 4-283378

[0005] In the refrigerator of Patent Document 1, the pre-cool operation time is changed based on the amount of frost, but if the amount of frost on the cooler becomes particularly large, the efficiency of heat exchange may be significantly reduced, and the temperature in the storage compartment may not be sufficiently reduced. In this case, the temperature in the storage compartment may become too high when the refrigerator switches to defrost operation, which may cause food to deteriorate.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a refrigerator that can suppress deterioration of food when performing a defrosting operation.

[0007] The refrigerator according to the present disclosure includes a main body having a cooler that cools the air by exchanging heat between a refrigerant flowing inside and the air, a storage compartment in which stored items are stored, and a cooler compartment in which the cooler is provided, a blower that sends air to the storage compartment, a compressor that compresses the refrigerant, a heater that heats the cooler, and a control device that controls the compressor, the blower, and the heater, and the control device sequentially performs a temperature adjustment operation that controls the compressor and the blower to adjust the temperature of the storage compartment to a set temperature, a pre-cool operation that controls the compressor and the blower to adjust the temperature of the storage compartment to a pre-cool set temperature that is lower than the set temperature, and a defrost operation that controls the heater to remove frost that has adhered to the cooler, and changes at least one of the compressor rotation speed, the blower rotation speed, and the pre-cool set temperature during the pre-cool operation based on an estimated amount of frost that has formed on the cooler before the defrost operation starts.

[0008] The refrigerator according to the present disclosure changes the pre-cooling intensity based on the estimated amount of frost. Therefore, the refrigerator according to the present disclosure can suppress the temperature rise of food during defrosting even when the amount of frost is large. Therefore, deterioration of food during defrosting operation can be suppressed.

[0009] 1 is a front view of a refrigerator according to embodiment 1. FIG. 2 is a cross-sectional view of the refrigerator according to embodiment 1. FIG. 3 is a hardware configuration diagram showing a control device according to embodiment 1. FIG. 4 is a hardware configuration diagram showing a control device according to embodiment 1. FIG. 5 is a functional block diagram of a refrigerator according to embodiment 1. FIG. 6 is a diagram for explaining control of devices for each operation mode according to embodiment 1. FIG. 7 is a flowchart showing a basic operation of the control device according to embodiment 1. FIG. 8 is a graph showing a relationship between an elapsed time from a previous defrosting operation of a refrigerator according to embodiment 1 and an estimated amount of frost. FIG. 9 is a graph showing a relationship between a door opening time of a refrigerator according to embodiment 1 and an amount of ventilation. FIG. 10 is a flowchart showing a calculation procedure for an estimated amount of frost according to embodiment 1. FIG. 11 is a flowchart showing a calculation procedure for an estimated amount of frost according to embodiment 1. FIG. 12 is a graph showing a relationship between an estimated amount of frost and an estimated defrosting time of a refrigerator according to embodiment 1. FIG. 13 is a diagram for explaining high-intensity pre-cooling operation of a refrigerator according to embodiment 1. FIG. 14 is a diagram for explaining low-intensity pre-cooling operation of a refrigerator according to embodiment 1. FIG. 15 is a diagram for explaining a method of correcting a conversion model according to a modified example of embodiment 1. FIG. 16 is a cross-sectional view of a refrigerator according to embodiment 2. FIG. 17 is a functional block diagram of a refrigerator according to embodiment 2. FIG. 18 is a functional block diagram of a refrigerator according to embodiment 3.

[0010] Embodiment 1. A refrigerator 100 according to embodiment 1 will be described below with reference to the drawings. Note that the same components are designated by the same reference numerals in each drawing. FIG. 1 is a front view of refrigerator 100 according to embodiment 1. FIG. 2 is a cross-sectional view of refrigerator 100 according to embodiment 1. FIG. 2 is a cross-sectional view of refrigerator 100 taken along the CC cross section of FIG. 1. In the Cartesian coordinate system XYZ shown in FIGS. 1 and 2, the left-right direction when refrigerator 100 is installed and ready for use is defined as the X-axis direction, the up-down direction is defined as the Z-axis direction, and the front-to-back direction is defined as the Y-axis direction. Refrigerator 100 is a device for cooling and preserving stored items such as food. Note that, hereinafter, the space in which refrigerator 100 is installed, such as the interior of a house, is referred to as the exterior space, and the air in the exterior space is referred to as exterior air.

[0011] 1 and 2 , the exterior of refrigerator 100 is formed by main body 10, which is a box with an open front. Main body 10 is formed, for example, by filling a space between an outer box (not shown) and an inner box (not shown) with rigid urethane foam. Inside main body 10, refrigerator compartment 1, ice maker compartment 2, switchable compartment 3, freezer compartment 4, and vegetable compartment 5 are formed. On the front of main body 10, refrigerator compartment door 11, ice maker compartment door 12, switchable compartment door 13, freezer compartment door 14, and vegetable compartment door 15 are provided.

[0012] The refrigerator compartment 1 is a storage compartment for storing food and other stored items. The refrigerator compartment 1 is maintained at a refrigeration temperature range of +3°C to +10°C. The refrigerator compartment 1 is divided into sections by multiple shelves 64, improving the storage capacity of the refrigerator compartment 1. The refrigerator compartment door 11 covers the opening at the front of the refrigerator compartment 1. The refrigerator compartment door 11 prevents heat from the air outside the refrigerator compartment from entering the refrigerator compartment 1. The refrigerator compartment door 11 is of a double-door type, with two doors covering the opening at the front of the refrigerator compartment 1.

[0013] Ice-making compartment 2 is a storage compartment for storing ice that has been made. Ice-making compartment 2 is formed below refrigerator compartment 1 and is adjacent to switchable compartment 3 on the left and right. Ice is stored in a storage case (not shown), which is a container with an open top. Ice-making compartment 2 is kept at a freezing temperature range of, for example, -17°C or below. A partition 61 separates ice-making compartment 2 from refrigerator compartment 1. Ice-making compartment door 12 is a retractable door that covers the opening on the front of ice-making compartment 2. Ice-making compartment door 12 prevents heat from the outside air from entering ice-making compartment 2.

[0014] The switchable compartment 3 is a storage compartment whose temperature can be switched between multiple temperature ranges. The switchable compartment 3 is formed below the refrigerator compartment 1 and is adjacent to the ice-making compartment 2 on the left and right. The switchable compartment 3 is provided with a storage case 71, which is an open-top container for storing food. When the switchable compartment 3 is shipped from the factory, it is set to maintain the interior of the switchable compartment 3 in the freezer temperature range. The switchable compartment 3 can be switched to multiple temperature ranges, all of which are lower than the temperatures inside the refrigerator compartment 1 and the vegetable compartment 5. In the first embodiment, it is set to the freezer temperature range. The switchable compartment 3 and the refrigerator compartment 1 are separated by a partition 61. The switchable compartment 3 and the ice-making compartment 2 are also separated by a partition (not shown). The switchable compartment door 13 is a pull-out door that covers the opening on the front of the switchable compartment 3. The switchable compartment door 13 prevents heat from outside the refrigerator compartment from entering the switchable compartment 3.

[0015] Freezer compartment 4 is a storage compartment where the temperature is maintained within the freezing temperature range. Freezer compartment 4 is formed below ice-making compartment 2 and switchable compartment 3. Freezer compartment 4 is provided with a storage case 72, which is a container with an open top and in which food is stored. Freezer compartment 4 is separated from ice-making compartment 2 and switchable compartment 3 by a partition 62. Freezer compartment door 14 is a drawer-type door that covers the opening on the front of freezer compartment 4. Freezer compartment door 14 prevents heat from the air outside the freezer from entering freezer compartment 4.

[0016] The vegetable compartment 5 is a storage compartment for storing vegetables. The vegetable compartment 5 is formed below the freezer compartment 4. The vegetable compartment 5 is kept at a refrigerated temperature range of, for example, +3°C to +10°C. The freezer compartment 4 is provided with a storage case 73, which is a container with an open top and in which food is stored. The vegetable compartment 5 and the freezer compartment 4 are separated by a partition 63. The vegetable compartment door 15 is a pull-out door that covers the opening on the front of the vegetable compartment 5. The vegetable compartment door 15 prevents heat from the air outside the refrigerator from entering the vegetable compartment 5.

[0017] Hereinafter, when there is no need to distinguish between refrigerator compartment 1, ice-making compartment 2, switchable compartment 3, freezer compartment 4, and vegetable compartment 5, they will simply be referred to as storage compartments. Also, when there is no need to distinguish between refrigerator compartment door 11, ice-making compartment door 12, switchable compartment door 13, freezer compartment door 14, and vegetable compartment door 15, they will simply be referred to as storage compartment doors.

[0018] The configuration of the storage compartment is not limited to the above-described form. For example, the layout of the storage compartment may be changed, such as by swapping the freezer compartment 4 and the vegetable compartment 5. The form of the storage compartment door may also be changed. For example, if the width of the refrigerator compartment 1 is relatively small, for example, 60 cm or less, the refrigerator compartment door 11 may be a single door. If a storage case is provided inside the storage compartment, the storage compartment door may be a drawer-type door, so that the storage case can be pulled out together with the door, making it easy to remove food from the storage case.

[0019] A machine chamber 7 and a cooler chamber 8 are formed at the rear of the main body 10. A compressor 41 is disposed in the machine chamber 7. Furthermore, a blower 42, a cooler 43, and a heater 44 are disposed in the cooler chamber 8, in that order from top to bottom. The compressor 41, a condenser (not shown), an expansion section (not shown), and the cooler 43 are connected in a ring shape by piping (not shown) to form a refrigeration cycle. The compressor 41 is, for example, an inverter type whose rotation speed can be controlled. The compressor 41 compresses a low-temperature, low-pressure gas refrigerant to a high-temperature, high-pressure state. The condenser exchanges heat between the high-temperature, high-pressure gas refrigerant sent from the compressor 41 and air. The condenser condenses the refrigerant to a low-temperature two-phase gas-liquid state or a liquid state. The expansion section is, for example, an electronic expansion valve or a capillary tube, and reduces the pressure and expands the low-temperature two-phase gas-liquid refrigerant or liquid refrigerant to a low-temperature, low-pressure liquid state. The cooler 43 performs heat exchange between the refrigerant in a low-temperature, low-pressure liquid state and the air. The cooler 43 evaporates the refrigerant and turns it into a low-temperature, low-pressure gas state. During this process, heat is absorbed from the periphery of the cooler 43, and the air in the cooler chamber 8 is cooled.

[0020] The blower 42 draws air from each storage chamber into the cooler chamber 8 and supplies it to the cooler 43. The blower 42 also sends air cooled by the cooler 43 to each storage chamber. The heater 44 is a glass tube heater or a carbon heater. The heater 44 is disposed below the cooler 43. The heater 44 is energized based on a signal from the control device 50 during defrosting operation, which will be described later, to heat the cooler 43. By heating the cooler 43 with the heater 44, frost adhering to the surface of the cooler 43 is melted and evaporated, and a decrease in the cooling capacity of the cooler 43 is suppressed.

[0021] Frost formation on the cooler 43 occurs when air containing water vapor is taken into the storage compartment and sent to the cooler chamber 8 by the blower 42, where it condenses when the temperature drops below the dew point in the cooler 43. Air containing water vapor is taken into the storage compartment when the storage compartment door is opened or closed to put food in or take food out. Even when the storage compartment door is closed, air containing water vapor is taken into the storage compartment through gaps between the storage compartment door and the main body 10, etc.

[0022] A refrigerator compartment damper 45 is provided in the airflow path from the cooler compartment 8 to the refrigerator compartment 1. A switching compartment damper 46 is provided in the airflow path from the cooler compartment 8 to the switchable compartment 3. Although not shown, an ice-making compartment damper is also provided in the airflow path from the cooler compartment 8 to the ice-making compartment 2. A vegetable compartment damper is also provided in the airflow path from the cooler compartment 8 to the vegetable compartment 5. The refrigerator compartment damper 45, the switchable compartment damper 46, the ice-making compartment damper, and the vegetable compartment damper can be opened and closed, allowing the flow of cold air when open and blocking the flow of cold air when closed. Note that no damper is provided corresponding to the freezer compartment 4. When the refrigerator compartment damper 45, the switchable compartment damper 46, the ice-making compartment damper, and the vegetable compartment damper are not distinguished, they are simply referred to as the storage compartment damper 40. The open / closed state of the storage compartment damper 40 is controlled by the control device 50.

[0023] The partition 61 is equipped with a refrigerator compartment open / close sensor 21 and a switchable compartment open / close sensor 23. The refrigerator compartment open / close sensor 21 detects whether the refrigerator compartment door 11 is open or closed, and transmits the detection result to the control device 50. The switchable compartment open / close sensor 23 detects whether the switchable compartment door 13 is open or closed, and transmits the detection result to the control device 50. Although not shown, the partition 61 is equipped with an ice-making compartment open / close sensor. The ice-making compartment open / close sensor detects whether the ice-making compartment door 12 is open or closed, and transmits the detection result to the control device 50.

[0024] A freezer compartment opening / closing sensor 24 is provided on the partition 62. The freezer compartment opening / closing sensor 24 detects whether the freezer compartment door 14 is open or closed, and transmits the detection result to the control device 50. A vegetable compartment opening / closing sensor 25 is provided on the partition 63. The vegetable compartment opening / closing sensor 25 detects whether the vegetable compartment door 15 is open or closed, and transmits the detection result to the control device 50. When there is no need to distinguish between the refrigerator compartment opening / closing sensor 21, the ice maker compartment opening / closing sensor, the switchable compartment opening / closing sensor 23, the freezer compartment opening / closing sensor 24, and the vegetable compartment opening / closing sensor 25, they will be simply referred to as storage compartment opening / closing sensors 20.

[0025] Refrigerating compartment 1 is equipped with a refrigerating compartment temperature sensor 31. The refrigerating compartment temperature sensor 31 measures the temperature of the air in refrigerating compartment 1 (hereinafter referred to as refrigerating compartment temperature) and transmits the measurement result to the control device 50. The switchable compartment 3 is equipped with a switchable compartment temperature sensor 33. The switchable compartment temperature sensor 33 measures the temperature of the air in switchable compartment 3 (hereinafter referred to as switchable compartment temperature) and transmits the measurement result to the control device 50.

[0026] A freezer compartment temperature sensor 34 is provided in the freezer compartment 4. The freezer compartment temperature sensor 34 measures the temperature of the air in the freezer compartment 4 (hereinafter referred to as the freezer compartment temperature) and transmits the measurement result to the control device 50. A vegetable compartment temperature sensor 35 is provided in the vegetable compartment 5. The vegetable compartment temperature sensor 35 measures the temperature of the air in the vegetable compartment 5 (hereinafter referred to as the vegetable compartment temperature) and transmits the measurement result to the control device 50.

[0027] Although not shown, ice making compartment 2 is equipped with an ice making compartment temperature sensor. The ice making compartment temperature sensor measures the temperature of the air inside ice making compartment 2 (hereinafter referred to as ice making compartment temperature) and transmits the measurement result to control device 50. When there is no need to distinguish between refrigerator compartment temperature sensor 31, ice making compartment temperature sensor, switchable compartment temperature sensor 33, freezer compartment temperature sensor 34, and vegetable compartment temperature sensor 35, they will simply be referred to as storage compartment temperature sensor 30. Similarly, when there is no need to distinguish between the refrigerator compartment temperature, ice making compartment temperature, switchable compartment temperature, freezer compartment temperature, and vegetable compartment temperature, they will be referred to as storage compartment temperatures.

[0028] A cooler temperature sensor 37 is provided on the surface of the cooler 43. The cooler temperature sensor 37 measures the temperature of the cooler 43 and transmits the measurement result to the control device 50. The installation position of the cooler temperature sensor 37 is adjusted so that the temperature of the refrigerant in the cooler 43 can be measured with high accuracy.

[0029] An outside temperature sensor 81 and an outside humidity sensor 82 are provided on the ceiling surface of the refrigerator 100. The outside temperature sensor 81 detects the temperature of the outside air (hereinafter referred to as the outside temperature T ｏｕｔ ) and transmits the measurement result to the control device 50. The outside humidity sensor 82 measures the relative humidity of the outside air (hereinafter referred to as the outside humidity H ｏｕｔ ) and transmits the measurement results to the control device 50.

[0030] A control device 50 is housed in the upper part of the rear surface of the main body 10. As will be described in detail later, the control device 50 controls the operation of each actuator. FIG. 3 is a hardware configuration diagram showing the control device 50 according to the first embodiment. As shown in FIG. 3, the control device 50 is configured with a processing circuit 101 such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array). FIG. 4 is a hardware configuration diagram showing the control device 50 according to the first embodiment. When the functions of the control device 50 are performed by software, the control device 50 may be configured with a processor 102 such as a CPU and a memory 103, as shown in FIG. 4. FIG. 4 shows that the processor 102 and the memory 103 are communicatively connected to each other via a bus 104. The functions of the control device 50 are realized by the processor 102 reading and executing a program stored in the memory 103. The memory 103 may be a non-volatile or volatile semiconductor memory or a removable recording medium.

[0031] 5 is a functional block diagram of refrigerator 100 according to the first embodiment. Control device 50 has device control unit 51, calculation unit 52, and storage unit 53. Device control unit 51 controls devices in each operation mode. Device control unit 51 controls the rotation speed of compressor 41, the rotation speed of blower 42, the energization state of heater 44, and the open / close state of storage chamber damper 40 based on measurement results from storage chamber open / close sensor 20, storage chamber temperature sensor 30, cooler temperature sensor 37, outside-compartment temperature sensor 81, and outside-compartment humidity sensor 82.

[0032] The calculation unit 52 calculates an estimated amount of frost and an estimated defrosting time, which will be described later.

[0033] The storage unit 53 stores, for a predetermined storage period, the measurement results of the storage chamber open / close sensor 20, the storage chamber temperature sensor 30, the cooler temperature sensor 37, the outside temperature sensor 81, and the outside humidity sensor 82, as well as the rotation speed of the compressor 41 and the rotation speed of the blower 42. The storage unit 53 also stores various parameters and calculation models used in the calculations by the calculation unit 52, as well as the calculation results by the calculation unit 52.

[0034] The control device 50 executes pull-down operation, temperature control operation, pre-cool operation, defrosting operation, and recovery operation as operation modes. The operation modes and the operation of the device control unit 51 for each operation mode will be described below.

[0035] (Pull-down operation) Pull-down operation is an operation mode for rapidly cooling the storage compartments after the refrigerator 100 is powered on. Pull-down operation is performed until the storage compartment temperature reaches the set temperature. The set temperature is a control target for the storage compartment temperature that is preset for each storage compartment. A default value is set for the set temperature when the refrigerator 100 is shipped from the factory, but the set temperature may be changed to reflect a temperature range desired by the user. Note that pull-down operation may be performed until the temperatures of all storage compartments reach the set temperature, or until the temperatures of one or more storage compartments reach the set temperature. In pull-down operation, the device control unit 51 rapidly cools the storage compartments by continuously operating the compressor 41 and the blower 42 without stopping them.

[0036] (Temperature Control Operation) The temperature control operation is an operation mode for maintaining the storage compartment temperature at a set temperature after the pull-down operation is completed. The temperature control operation is performed until a defrosting condition, which will be described later, is satisfied. The refrigerator 100 performs the temperature control operation in a normal state in which defrosting of the cooler 43 is not required.

[0037] 6 is a diagram for explaining the control of devices for each operation mode according to the first embodiment. The device control unit 51 starts the compressor 41 and the blower 42 when the freezer compartment temperature measured by the freezer compartment temperature sensor 34 becomes equal to or higher than a predetermined start-up temperature. The start-up temperature is a temperature higher than the set temperature of the freezer compartment 4. The device control unit 51 determines the start-up rotation speed of the compressor 41 and the start-up rotation speed of the blower 42 based on the outside-compartment temperature T detected by the outside-compartment temperature sensor 81. ｏｕｔAs will be described in detail later, the equipment control unit 51 controls the compressor 41 during the temperature adjustment operation so as to rotate at a relatively slower speed than the compressor 41 during the pre-cool operation, as shown in Fig. 6. Similarly, the equipment control unit 51 controls the blower 42 during the temperature adjustment operation so as to rotate at a relatively slower speed than the blower 42 during the pre-cool operation, as shown in Fig. 6.

[0038] When the time during which compressor 41 has been continuously operating reaches or exceeds the threshold time, i.e., when the freezer compartment temperature does not fall below the stop temperature during the threshold time, device control unit 51 determines that the thermal load on refrigerator 100 is large. At this time, device control unit 51 gradually increases the rotation speed of compressor 41 and the rotation speed of blower 42 to increase the freezing capacity, thereby lowering the freezer compartment temperature below the stop temperature.

[0039] Furthermore, the equipment control unit 51 stops the compressor 41 and the blower 42 when the temperature in the freezing compartment falls below a predetermined stop temperature. The stop temperature is a temperature lower than the set temperature of the freezing compartment 4. For simplicity of illustration, FIG. 6 does not show a state in which the compressor 41 and the blower 42 are stopped during temperature adjustment operation.

[0040] With respect to refrigerator compartment 1, the device control unit 51 opens refrigerator compartment damper 45 when the refrigerator compartment temperature measured by refrigerator compartment temperature sensor 31 reaches or exceeds a predetermined refrigerator compartment damper opening temperature. The refrigerator compartment damper opening temperature is a temperature higher than the set temperature of refrigerator compartment 1. Furthermore, when the refrigerator compartment temperature falls below a predetermined refrigerator compartment damper closing temperature, the refrigerator compartment damper 45 closes. The refrigerator compartment damper closing temperature is a temperature lower than the set temperature of refrigerator compartment 1. For simplicity of illustration, FIG. 6 does not show a case where the storage compartment damper 40 is closed during temperature adjustment operation.

[0041] As with refrigerator compartment 1, device control unit 51 opens the ice-making compartment damper in ice-making compartment 2 when the ice-making compartment temperature measured by the ice-making compartment temperature sensor reaches or exceeds a predetermined ice-making compartment damper opening temperature. The ice-making compartment damper opening temperature is a temperature higher than the set temperature of ice-making compartment 2. Furthermore, the ice-making compartment damper closes when the ice-making compartment temperature falls below a predetermined ice-making compartment damper closing temperature. The ice-making compartment damper closing temperature is a temperature lower than the set temperature of ice-making compartment 2.

[0042] As with the refrigerator compartment 1, the device control unit 51 opens the switchable compartment damper 46 for the switchable compartment 3 when the switchable compartment temperature measured by the switchable compartment temperature sensor 33 reaches or exceeds a predetermined switchable compartment damper opening temperature. The switchable compartment damper opening temperature is a temperature higher than the set temperature of the switchable compartment 3. Furthermore, the switchable compartment damper 46 closes when the switchable compartment temperature falls below a predetermined switchable compartment damper closing temperature. The switchable compartment damper closing temperature is a temperature lower than the set temperature of the switchable compartment 3.

[0043] As with the refrigerator compartment 1, the device control unit 51 opens the vegetable compartment damper when the vegetable compartment temperature measured by the vegetable compartment temperature sensor 35 reaches or exceeds a predetermined vegetable compartment damper opening temperature. The vegetable compartment damper opening temperature is a temperature higher than the set temperature of the vegetable compartment 5. Furthermore, the vegetable compartment damper closes when the vegetable compartment temperature falls below a predetermined vegetable compartment damper closing temperature. The vegetable compartment damper closing temperature is a temperature lower than the set temperature of the vegetable compartment 5.

[0044] The device control unit 51 determines that the defrost condition is satisfied when the time since the start of the pull-down operation has elapsed a first duration, when the time since the end of the previous defrost operation has elapsed a second duration, or when the number of times the compressor 41 has been activated exceeds a threshold number. When the defrost condition is satisfied, the device control unit 51 generates a defrost signal. The defrost signal is generated to transition the operation mode to defrost operation because frost may have formed on the cooler 43. The first duration and the second duration are times when the possibility of frost forming on the cooler 43 is sufficiently high, and are set in advance through experiments, etc. In the refrigerator 100 of the first embodiment, a pre-cool operation is performed prior to the defrost operation, and a recovery operation is performed after the defrost operation is completed. Note that FIG. 6 illustrates a case in which the defrost signal is generated while the compressor 41 and the blower 42 are operating. However, as described above, if the freezer compartment temperature falls below the stop temperature, the compressor 41 and the blower 42 may stop during temperature adjustment operation. Therefore, the defrost signal may be generated when the compressor 41 and the blower 42 are stopped.

[0045] (Pre-cool operation) Pre-cool operation is an operation mode for lowering the temperature in the storage compartment below that during temperature control operation before performing defrost operation. By performing pre-cool operation, the temperature in the storage compartment is prevented from rising excessively due to the defrost operation. Pre-cool operation is performed until the pre-cool end condition described below is met.

[0046] As shown in Fig. 6, the equipment control unit 51 controls the rotation speed of the compressor 41 during pre-cool operation so that it is higher than the rotation speed of the compressor 41 during temperature adjustment operation. That is, the compressor 41 rotates at a relatively "high speed" during pre-cool operation, and the compressor 41 rotates at a relatively "low speed" during temperature adjustment operation. Similarly, the equipment control unit 51 controls the rotation speed of the blower 42 during pre-cool operation so that it is higher than the rotation speed of the blower 42 during temperature adjustment operation. That is, the blower 42 rotates at a relatively "high speed" during pre-cool operation, and the blower 42 rotates at a relatively "low speed" during temperature adjustment operation.

[0047] The pre-cool end condition is satisfied when either the freezer compartment temperature falls below the pre-cool set temperature or the time during which pre-cool operation is being performed is equal to or exceeds the pre-cool end time. The pre-cool set temperature is a temperature lower than the set temperature for temperature control operation. The pre-cool end time is set to determine the end of pre-cool operation even if the freezer compartment temperature does not fall below the pre-cool set temperature when there is a large amount of frost on the cooler 43. In other words, the pre-cool end time indicates the upper limit of the time during which pre-cool operation can be performed.

[0048] The device control unit 51 controls the storage chamber damper 40 to an open state, and sends cool air to the storage chamber during the pre-cool operation. The device control unit 51 also stops the supply of electricity to the heater 44.

[0049] As will be described in detail later, the device control unit 51 adjusts the pre-cooling intensity based on the estimated defrosting time estimated by the calculation unit 52. The pre-cooling intensity is the strength with which the storage compartment is cooled during pre-cooling operation, and is adjusted by changing one or more of the rotation speeds of the compressor 41 and the blower 42 during pre-cooling operation, the pre-cooling set temperature, and the pre-cooling end time. However, even when the rotation speed of the compressor 41 during pre-cooling operation is controlled to the lowest, it is still higher than the rotation speed of the compressor 41 when controlled to the highest during temperature adjustment operation.

[0050] (Defrosting Operation) The defrosting operation is an operation mode for removing frost that has adhered to the cooler 43. The device control unit 51 defrosts the cooler 43 by energizing the heater 44 and heating the cooler 43. The defrosting operation is performed until the cooler temperature reaches or exceeds the defrost setting temperature. The defrost setting temperature is a temperature higher than the melting point of frost.

[0051] During the defrosting operation, the device control unit 51 stops the operation of the compressor 41 and the blower 42. The device control unit 51 also closes the storage chamber damper 40.

[0052] During the defrosting operation, cooling of the storage compartment is stopped. Also, since heater 44 is operated to generate heat, the power consumption of refrigerator 100 is greater than that during temperature control operation. For this reason, it is desirable to minimize the number of defrosting operations per week, for example.

[0053] (Recovery Operation) Recovery operation is an operation mode for rapidly cooling the storage compartment to which the supply of cold air has been stopped during defrosting operation. Recovery operation is performed until the storage compartment temperature reaches the set temperature. The device control unit 51 starts the compressor 41 before the blower 42. After the standby time has elapsed, the device control unit 51 starts the blower 42 to send cold air to the storage compartment. The standby time is the time set for sending cold air to the storage compartment. The standby time is set to the length of time required for the cooler temperature to drop to a level that allows the storage compartment to be cooled.

[0054] The equipment control unit 51 controls the rotation speed of the compressor 41 during the recovery operation so that it is higher than the rotation speed of the compressor 41 during the temperature adjustment operation. Similarly, the equipment control unit 51 controls the rotation speed of the blower 42 during the recovery operation so that it is higher than the rotation speed of the blower 42 during the temperature adjustment operation. This allows the temperature in the storage compartment to quickly return to the set temperature.

[0055] The device control unit 51 controls the storage chamber damper 40 to an open state, and sends cool air to the storage chamber during the recovery operation. The device control unit 51 also stops the supply of electricity to the heater 44.

[0056] 6 shows the rotation speed of the compressor 41 and the rotation speed of the blower 42 at two stages, high speed and low speed, but the rotation speed of the compressor 41 and the rotation speed of the blower 42 in the recovery operation may be different from the rotation speed in the pre-cool operation. For example, the rotation speed of the compressor 41 and the rotation speed of the blower 42 in the recovery operation may be higher than the rotation speed of the compressor 41 and the rotation speed of the blower 42 in the pre-cool operation.

[0057] Fig. 7 is a flowchart showing the basic operation of the control device 50 according to the first embodiment. The basic operation of the control device 50 will be described using Fig. 7. First, when the power is turned on, the device control unit 51 of the control device 50 executes a pull-down operation to rapidly cool the storage compartment (step S1). During the pull-down operation, the device control unit 51 determines whether the temperature in the storage compartment has become equal to or lower than the set temperature (step S2). If the temperature in the storage compartment is higher than the set temperature (step S2: NO), the device control unit 51 continues the pull-down operation until the temperature in the storage compartment becomes equal to or lower than the set temperature (step S1).

[0058] If the temperature in the storage compartment is equal to or lower than the set temperature (step S2: YES), the device control unit 51 executes the temperature control operation to maintain the storage compartment at the set temperature (step S3). During the temperature control operation, the device control unit 51 determines whether the defrosting condition is satisfied (step S4). If the defrosting condition is not satisfied (step S4: NO), the device control unit 51 continues the temperature control operation (step S3).

[0059] If the defrosting condition is satisfied (step S4: YES), the device control unit 51 executes pre-cool operation to lower the temperature of the storage compartment below that during temperature control operation (step S5). During the pre-cool operation, the device control unit 51 determines whether the pre-cool termination condition is satisfied (step S6). If the pre-cool termination condition is not satisfied (step S6: NO), the device control unit 51 continues the pre-cool operation (step S5).

[0060] If the pre-cooling end condition is satisfied (step S6: YES), the device control unit 51 executes the defrosting operation to defrost the cooler 43 (step S7). During the temperature adjustment operation, the device control unit 51 determines whether the cooler temperature is equal to or higher than the defrosting set temperature (step S8). If the cooler temperature is lower than the defrosting set temperature (step S8: NO), the device control unit 51 continues the defrosting operation (step S7).

[0061] If the cooler temperature is equal to or higher than the defrost setting temperature (step S8: YES), the device control unit 51 executes recovery operation to rapidly cool the storage compartment (step S9). During the recovery operation, the device control unit determines whether the storage compartment temperature is equal to or lower than the setting temperature (step S10). If the storage compartment temperature is higher than the setting temperature (step S10: NO), the device control unit 51 continues the recovery operation until the storage compartment temperature is equal to or lower than the setting temperature (step S9).

[0062] If the temperature in the storage compartment is equal to or lower than the set temperature (step S10: YES), the device control unit 51 executes a temperature adjustment operation to maintain the temperature in the storage compartment at the set temperature (step S3).

[0063] (Regarding Changing the Pre-Cooling Intensity) As described above, the device control unit 51 changes the pre-cooling intensity based on the estimated defrosting time estimated by the calculation unit 52 when the defrost signal is generated. Here, a method for estimating the estimated frost amount and the estimated defrosting time by the calculation unit 52 will be described. The calculation unit 52 has a frost amount calculation unit 52a and a defrosting time calculation unit 52b. The frost amount calculation unit 52a calculates the estimated frost amount. The estimated frost amount is an estimated amount of frost that has adhered to the cooler 43 from the end of the previous defrosting operation to the start of the next defrosting operation. The defrosting time calculation unit 52b calculates the estimated defrosting time by converting the estimated frost amount using a conversion model. The estimated defrosting time is an estimated time required to complete the defrosting operation. First, a method for calculating the frost amount will be described.

[0064] [Calculation of Estimated Amount of Frost] Frost amount calculation unit 52a calculates the amount of frost with the door closed, the amount of frost with the door open, and the amount of frost in the pre-cooling mode, and then calculates the estimated amount of frost by summing these amounts. The amount of frost with the door closed refers to the amount of frost that adheres to cooler 43 when the storage compartment door is closed. Even when the storage compartment door is closed, while compressor 41 and blower 42 are operating, cool air inside the storage compartment is circulated by blower 42, creating a negative pressure inside the storage compartment relative to the air outside the storage compartment. Therefore, air containing water vapor flows into the storage compartment from the outside space through a small gap between main body 10 and the storage compartment door. When this air circulates inside refrigerator 100 and reaches cooler 43, frost forms.

[0065] The amount of frost formed when the door is open means the amount of frost that adheres to cooler 43 when the storage compartment door is open. When the storage compartment door is open, air containing water vapor flows into the storage compartment from the space outside the refrigerator, and frost forms when this air circulates inside refrigerator 100 and reaches cooler 43.

[0066] The pre-cool frost amount is the amount of frost expected to form during pre-cool operation at the time the defrost signal is generated.

[0067] FIG. 8 is a graph showing the relationship between the elapsed time since the previous defrosting operation of refrigerator 100 according to embodiment 1 and the estimated amount of frost. Point A in FIG. 8 indicates the amount of frost at the time the defrost signal is generated, i.e., the sum of the open-door frost amount and the closed-door frost amount. During recovery operation or temperature control operation after the defrosting operation is completed, frost amount calculation unit 52a calculates the closed-door frost amount every time a predetermined door-closing calculation time (e.g., one minute) elapses and adds it to the estimated frost amount. Furthermore, during recovery operation or temperature control operation, frost amount calculation unit 52a calculates the open-door frost amount every time the storage compartment door is opened or closed and adds it to the estimated frost amount. In FIG. 8 , ΔX represents one of the open-door frost amounts calculated by opening and closing the storage compartment door once. When the storage compartment door is open, more air flows into the storage compartment than when the storage compartment is closed, resulting in a larger amount of frost per hour than when the storage compartment is closed.

[0068] Point B in Figure 8 indicates the estimated amount of frost at the end of pre-cooling operation, i.e., the sum of the closed door frost amount, the open door frost amount, and the pre-cooling frost amount. The frost amount calculation unit 52a calculates the pre-cooling frost amount, which is the amount of frost that is expected to be estimated when the defrost signal is generated. In pre-cooling operation, the rotation speeds of the compressor 41 and the blower 42 are higher than in temperature control operation, so the amount of frost that forms per hour is expected to be greater than in temperature control operation. Note that the predicted pre-cooling operation frost amount here is for the case where the pre-cooling intensity is not changed, i.e., the pre-cooling intensity is medium.

[0069] Specific parameters for calculating the amount of frost formed when the door is opened, the amount of frost formed when the door is closed, and the amount of frost formed when the door is pre-cooled will be described. First, the amount of frost formed when the door is opened and the amount of frost formed when the door is closed will be described. The amount of frost formed when a time t has elapsed since the end of the previous defrosting operation, m, is expressed by the following equation (1):

[0070]

[0071] Here, the first term on the right side indicates the amount of frost formed on the closed door, and the second term on the right side indicates the amount of frost formed on the open door. ｇ / Δt is the amount of frost formed when the door is closed in a predetermined unit time. Note that the unit time is an arbitrary time for expressing the amount of frost formed when the door is open per hour. Δm ｖ is the amount of frost that forms when the door is opened and closed once. ｖ is the number of times the storage compartment door is opened and closed during recovery operation and temperature adjustment operation.

[0072] The amount of frost formed on the closed door will be explained. The amount of frost formed on the open door per unit time Δm ｇ / Δt is expressed by the following equation (2).

[0073]

[0074] n ｃ is the rotation speed of the compressor 41, and n ｆ is the rotation speed of the blower 42. ｏｕｔ is the absolute humidity of the air outside the cabinet. １ is the compressor rotation speed n ｃ , fan rotation speed n ｆ , and the absolute humidity AH of the air outside the cabinet ｏｕｔ With the variable, the amount of frost formed when the door is opened Δm ｇ This is a function for calculating the air flow rate Δt / Δt when the storage compartment door is closed, the amount of water vapor contained in the air flowing into the storage compartment, and the rate of frost formation on the cooler 43 are calculated based on the compressor rotation speed n ｃ , fan rotation speed n ｆ , and absolute humidity outside the cabinet AH ｏｕｔ Specifically, the amount of air flowing into the storage chamber is determined by the fan rotation speed n ｆ The amount of water vapor contained in the air flowing into the storage compartment is determined by the absolute humidity outside the storage compartment, AH ｏｕｔThe speed of frost formation on the cooler 43 is determined by the compressor rotation speed n ｃ and the fan rotation speed n ｆ The amount of frost formed on the door when it is opened and the unit time Δm ｇ The relationship between f and Δt is determined by the shape of the refrigerator 100, such as the width and height of the refrigerator 100, and １ is obtained by experiment and stored in the storage unit 53.

[0075] Outside absolute humidity AH ｏｕｔ is expressed by, for example, the following equation (3).

[0076]

[0077] f ２ Is T ｏｕｔ and H ｏｕｔ is a function of ｏｕｔ To the right of this is the temperature T ｏｕｔ This is the Tetens equation for calculating the saturated water vapor content of air.

[0078] As described above, the frost amount calculation unit 52a calculates the compressor rotation speed n ｃ , fan rotation speed n ｆ , outside temperature T ｏｕｔ , and the humidity outside the cabinet H ｏｕｔ As described above, during the temperature control operation, the compressor 41 and the blower 42 may be stopped. Therefore, the frost amount calculation unit 52a calculates the amount of frost formed on the closed door only while the compressor 41 is operating.

[0079] The amount of frost formed when the storage compartment door is opened and closed once will be explained. ｖ is expressed by the following equation (4).

[0080] M ｖ is the ventilation volume per opening and closing of the storage room door. ｏｕｔ As mentioned above, f is the absolute humidity outside the cabinet. ３ is the ventilation volume M ｖ and absolute humidity outside the cabinet AH ｏｕｔ The amount of frost formed on the door by opening and closing the storage compartment door once is calculated as a variable. ｖIt is a function to calculate the amount of frost formed on the door by opening and closing the storage compartment door once. ｖ The relationship between ３ is obtained by experiment and stored in the storage unit 53.

[0081] Ventilation volume M ｖ is expressed by, for example, the following equation (5).

[0082]

[0083] t ｏｐｅｎ is the time that the storage compartment door is opened in one opening and closing. ｏｐｅｎ Here, FIG. 9 is a graph showing the relationship between the door opening time of the refrigerator 100 according to the first embodiment and the ventilation amount. As shown in FIG. 9, the ventilation amount M ｖ is the door opening time t ｏｐｅｎ is not linearly proportional to the door opening time t ｏｐｅｎ The slope decreases as increases.

[0084] In addition, the ventilation volume M ｖ varies depending on the type of opening of the storage compartment door, i.e., whether the storage compartment door is a double door like the refrigerator compartment door 11 or a drawer door. ｖ The ventilation volume M also varies depending on the volume of the storage compartment. Furthermore, even when comparing the freezer compartment 4 and the vegetable compartment 5, which have the same drawer-type door and approximately the same volume, the temperature difference between the storage compartment and the air outside the storage compartment is different, which causes a difference in buoyancy (difference in density between the air inside the storage compartment and the air outside the storage compartment). In other words, the ventilation volume M ｖ The ventilation rate M ｖ It also varies depending on the shape of the storage case for each storage room.

[0085] In light of the above circumstances, f ４ The storage compartment has coefficients a and b determined by the door opening method, the case shape, the set temperature, etc., and the coefficients a and b and the door opening time t ｏｐｅｎ By this, ventilation volume M ｖ The door opening time t ｏｐｅｎ The coefficients a and b for each storage compartment, and the ventilation volume Mｖ The relationship between ４ is obtained by experiment and stored in the storage unit 53. ４ In this example, different values ​​are set for the coefficients a and b depending on the storage compartment door whose opening or closing is detected. The coefficients a and b are set based on the results of experiments conducted under the conditions of each model of refrigerator 100. In this way, the amount of frost formed on the door when it is opened Δm ｖ is the ventilation volume M with a different coefficient set for each storage room. ｖ Since it is calculated based on the door opening time t ｏｐｅｎ This calculation is more accurate than when calculating ventilation volume by integrating the above.

[0086] In addition, ventilation volume M ｖ The coefficients a and b in the first embodiment are determined by assuming the occupancy rate to be a representative value (e.g., 50%).

[0087] As described above, the frost amount calculation unit 52a calculates the door opening time t ｏｐｅｎ , outside temperature T ｏｕｔ , and the humidity outside the cabinet H ｏｕｔ The amount of frost formed when the door is opened is calculated based on the above.

[0088] Next, the amount of pre-cool frost will be described. ｐ is the representative time of the pre-cooling, and C ｖ，ｐ The amount of pre-cooling frost, mp, when the predicted number of opening and closing times is set to t, is expressed by the following equation (6): ｐ is the expected time for which the pre-cooling operation is performed. ｐ is the average time of the pre-cool operation obtained in advance by an experiment or the like for each model of the refrigerator 100, for example. ｖ，ｐ is the predicted number of times the storage compartment door is opened and closed during pre-cool operation. ｖ，ｐ is the pre-cool representative time t ｐThe opening and closing frequency is calculated by multiplying the total number of times the storage compartment was opened and closed during a calculation period in the past (hereinafter referred to as the total number of times the storage compartment was opened and closed) by the length of the same period. The calculation period is, for example, the period during which the temperature control operation was performed in the past week.

[0089]

[0090] Here, the first term on the right side indicates the amount of frost formed corresponding to the amount of frost formed when the door is closed during pre-cooling operation. Therefore, the amount of frost formed when the door is open per unit time during pre-cooling operation Δm ｇ，ｐ / Δt is expressed by the following equation (7), similarly to the amount of frost formed on the closed door described above.

[0091]

[0092] Here, the variables used to calculate the amount of frost formed when the door is closed and the corresponding variables during pre-cooling operation are marked with ",p". ｇ，ｐ / Δt is the amount of frost formed on the door when it is closed per unit time. ｖ，ｐ is the amount of frost formed when the door is opened and closed once during pre-cool operation. ｃ，ｐ is the representative rotation speed of the compressor 41 during the pre-cool operation. ｃ，ｐ is the rotation speed of the compressor 41 when the pre-cooling strength is medium. ｃ，ｐ is the average compressor rotation speed during pre-cool operation obtained in advance by experiments or the like for each model of the refrigerator 100, for example. ｆ，ｐ is the representative rotation speed of the blower 42 during the pre-cool operation. ｆ，ｐ is the rotation speed of the compressor 41 when the pre-cooling strength is medium. ｆ，ｐ is the average fan rotation speed during pre-cool operation obtained in advance by experiments or the like for each model of the refrigerator 100. ｏｕｔ，ｐ is the absolute humidity outside the refrigerator at the time the defrost signal is generated. ｏｕｔ，ｐ is the outside temperature at the time the defrost signal is generated. ｏｕｔ，ｐ is the outside temperature at the time the defrost signal is generated.

[0093] The second term on the right side indicates the amount of frost formation corresponding to the amount of frost formation when the storage compartment door is opened during pre-cooling operation. ｖ，ｐ is expressed by the following equation (8), similarly to the above-mentioned door-opening frost amount Δmv.

[0094]

[0095] M ｖ，ｐ is the ventilation volume per opening and closing of the storage compartment door during pre-cooling operation. ｏｕｔ，ｐ As described above, t is the absolute humidity of the outside air at the time when the defrost signal is generated. ｏｐｅｎ，ｐ is the predicted door opening time during pre-cool operation. ｏｐｅｎ，ｐ is the predicted door opening time for one opening and closing of the storage compartment door during pre-cooling operation. ｏｐｅｎ，ｐ is calculated by dividing the total opening and closing time of the storage compartment during the calculation period (hereinafter referred to as the total opening and closing time) by the total number of openings and closings during the same period.

[0096] Note that the function f ４ The coefficients a and b used to calculate the ventilation volume Mv are set to different values ​​depending on the storage compartment door whose opening or closing is detected. In equation (8), the coefficients a and b are omitted, but the ventilation volume Mv per opening or closing is ｖ，ｐ For example, the coefficients a and b may be set based on the ratio of the total open time of each storage compartment door to the total open time of all storage compartment doors during the calculation period. ｖ，ｐ When calculating the ventilation volume M ｖ Similarly, the coefficients a and b are determined on the assumption that the occupancy rate is a representative value (for example, 50%).

[0097] As described above, the frost amount calculation unit 52a calculates the frost amount based on the compressor representative rotation speed n ｃ，ｐ , blower representative rotation speed n ｆ，ｐ , outside temperature T ｏｕｔ，ｐ , outside humidity H ｏｕｔ，ｐ , pre-cool representative time t ｐThe amount of pre-cool frost is calculated based on the total number of times the storage compartment door is opened and closed during the calculation period, the total opening and closing time, and the length of the calculation period.

[0098] The calculation procedure for the estimated amount of frost will be described using Figures 10 and 11 . Figure 10 is a flowchart showing the calculation procedure for the estimated amount of frost according to the first embodiment. Figure 11 is a flowchart showing the calculation procedure for the estimated amount of frost according to the first embodiment. The process shown in Figure 11 is performed consecutively to the process shown in Figure 10 . Figure 10 shows the calculation procedure for the estimated amount of frost from the timing when the defrosting operation is completed. After the defrosting operation is completed, the operation mode transitions from recovery operation to temperature control operation, but Figures 10 and 11 do not mention the transition from recovery operation to temperature control operation. The calculation method for the amount of frost with the door closed and the amount of frost with the door open is the same whether the operation mode is recovery operation or temperature control operation.

[0099] First, when the defrosting operation is completed, the frost amount calculation unit 52a resets the estimated amount of frost (step S11). Next, the frost amount calculation unit 52a resets the elapsed time (step S12). The elapsed time is a variable that serves as a timer for adding the amount of frost formed when the door is closed for each calculated time period. Then, the frost amount calculation unit 52a monitors the output status of the defrost signal (step S13). If the defrost signal is not output (step S13: NO), the frost amount calculation unit 52a monitors the open / closed state of the storage compartment door (step S14) and calculates the amount of frost formed when the door is closed or when the door is open depending on the open / closed state (steps S14 to S23).

[0100] If the storage compartment door is closed (step S14: NO), the frost amount calculation unit 52a calculates the closed-door frost amount (steps S15 to S19). In calculating the closed-door frost amount, the frost amount calculation unit 52a first monitors the operating state of the compressor 41 (step S15), as shown in Fig. 11. If the compressor 41 is not operating (step S15: NO), it is assumed that no outside air is flowing into the storage compartment. Therefore, the frost amount calculation unit 52a does not calculate the closed-door frost amount, and instead monitors the output status of the defrost signal again (step S13).

[0101] If the compressor 41 is operating (step S15: YES), the frost amount calculation unit 52a determines that outside air is flowing into the storage compartment, and adds the time since the previous execution of this process to the elapsed time (step S16). Then, the frost amount calculation unit 52a determines whether the elapsed time is equal to or greater than the door-closed calculation time (step S17). If the elapsed time is less than the door-closed calculation time (step S17: NO), the frost amount calculation unit 52a does not calculate the door-closed frost amount, and again monitors the output status of the defrost signal (step S13). If the elapsed time is equal to or greater than the door-closed calculation time (step S17: YES), the frost amount calculation unit 52a calculates the outside temperature A ｏｕｔ , outside humidity H ｏｕｔ , compressor rotation speed n ｃ , and the fan rotation speed n ｆ (Step S18). Then, the frost amount calculation unit 52a calculates the outside temperature T ｏｕｔ , outside humidity H ｏｕｔ , compressor rotation speed n ｃ , and the fan rotation speed n ｆ The frost amount calculation unit 52a calculates the amount of frost formed on the closed door during the door closing calculation time based on the calculated value of the frost amount, and adds the calculated amount of frost to the estimated amount of frost (step S19). After the amount of frost formed on the closed door is added to the estimated amount of frost, the waiting time is reset (step S12), and the frost amount calculation unit 52a again monitors the output status of the defrost signal (step S13).

[0102] If the storage compartment door is open (step S14: YES), the frost amount calculation unit 52a calculates the amount of frost formed on the open door (steps S20 to S23). ｏｕｔ , outside humidity H ｏｕｔ (Step S20). Next, the frost amount calculation unit 52a monitors the open / closed state of the storage compartment door (Step S21). If the storage compartment door is open (Step S21: NO), the frost amount calculation unit 52a continues to monitor the open / closed state until the storage compartment door is closed (Step S21). If the storage compartment door is closed (Step S21: YES), the frost amount calculation unit 52a subtracts the time the storage compartment door is closed from the time the storage compartment door is open to calculate the door open time t ｏｐｅｎ (Step S22). Then, the frost amount calculation unit 52a calculates the door opening time t ｏｐｅｎ , outside temperature Tｏｕｔ , and the humidity outside the cabinet H ｏｕｔ The amount of frost formed by closing the door is calculated based on the calculated value and added to the estimated amount of frost formed so far (step S23). After the amount of frost formed by closing the door is added to the estimated amount of frost formed, the frost amount calculation unit 52a again monitors the output status of the defrost signal (step S13).

[0103] When the defrost signal is output (step S13: YES), the frost amount calculation unit 52a calculates the pre-cool frost amount (steps S26 to S27). ｏｕｔ , and the humidity outside the cabinet H ｏｕｔ Next, the frost amount calculation unit 52a calculates the compressor representative rotation speed n ｃ，ｐ , blower representative rotation speed n ｆ，ｐ , and the pre-cool representative time t ｐ (Step S25). Next, the frost amount calculation unit 52a obtains the pre-cool representative time t ｐ , the total number of opening and closing times in the calculation period, and the predicted number of opening and closing times C based on the length of the calculation period. ｖ，ｐ and calculate the predicted door opening time t based on the total opening and closing time and the total number of opening and closing times during the calculation period. ｏｐｅｎ，ｐ (Step S26). Then, the frost amount calculation unit 52a calculates the compressor representative rotation speed n ｃ，ｐ , blower representative rotation speed n ｆ，ｐ , outside temperature T ｏｕｔ，ｐ , outside humidity H ｏｕｔ，ｐ , pre-cool representative time t ｐ , predicted opening and closing times C ｖ，ｐ , and predicted door opening time t ｏｐｅｎ , p, and the pre-cool frost amount is calculated based on the calculated values ​​of p and p, and is added to the estimated frost amount calculated so far (step S27). In this way, the estimated frost amount from the end of the previous defrosting operation to the start of the current defrosting operation is calculated.

[0104] [Calculation of Estimated Defrosting Time] The defrosting time calculation unit 52b calculates an estimated defrosting time using a conversion model from the estimated frost amount calculated by the frost amount calculation unit 52a. FIG. 12 is a graph showing the relationship between the estimated frost amount and the estimated defrosting time for the refrigerator 100 according to the first embodiment. The conversion model is a calculation formula that shows the relationship between the estimated frost amount and the estimated defrosting time, and is stored in the storage unit 53. The conversion model is set for each model of the refrigerator 100 through prior testing, etc. As shown in FIG. 12 , when the conversion model defines the relationship between the estimated frost amount (x-coordinate) and the estimated defrosting time (y-coordinate) using a linear function, information on the slope (Δy / Δx) and the y-intercept is stored as the conversion model. Note that even if no frost is present on the cooler 43, the cooler chamber 8 in which the cooler 43 is installed and the structures around the cooler 43 are heated, and it takes time for the cooler temperature to rise. Therefore, the y-intercept in FIG. 12 is greater than 0. In other words, even if the estimated amount of frost is zero, the estimated defrosting time will not be zero.

[0105] 12 shows a case where the relationship between the estimated amount of frost and the estimated defrosting time is determined by a linear function, but the relationship may be determined by other relational expressions. For example, the relationship between the estimated amount of frost and the estimated defrosting time may be determined by a quadratic expression depending on factors such as the size of the cooler 43 and the heat generation amount and arrangement of the heater 44. However, if the heat generation amount per unit time of the heater 44 is constant, the relational expression representing the relationship between the amount of frost and the estimated defrosting time will be linear.

[0106] [Changing Pre-cooling Intensity] The equipment control unit 51 changes the pre-cooling intensity based on the estimated defrosting time calculated by the frost amount calculation unit 52a. Here, it is assumed that the pre-cooling intensity is divided into three levels: low intensity, medium intensity, and high intensity. The pre-cooling intensity changes by changing any of the rotation speeds of the compressor 41 and the blower 42 during pre-cooling operation, the pre-cooling set temperature, and the pre-cooling end time. When the pre-cooling intensity is medium intensity, the rotation speeds of the compressor 41 and the blower 42 during pre-cooling operation, the pre-cooling set temperature, and the pre-cooling end time are set to predetermined standard values. Note that when the pre-cooling intensity is medium intensity, the rotation speed of the compressor 41 during pre-cooling operation is set to the compressor representative rotation speed n used to calculate the pre-cooling frost amount by the frost amount calculation unit 52a. ｃ，ｐ The rotation speed of the blower 42 during the pre-cooling operation is the same as the blower representative rotation speed n ｆ，ｐ is the same as

[0107] When the estimated defrosting time is equal to or longer than the first threshold time, the device control unit 51 increases the pre-cooling intensity more than when the estimated defrosting time is shorter than the first threshold time. That is, the pre-cooling intensity is changed from medium to high. The first threshold time is, for example, 15 minutes. The pre-cooling intensity is changed from medium to high by selecting at least one of the following measures. The first measure is to reduce the pre-cooling setting temperature below the standard value for medium intensity. The second measure is to increase the rotation speed of the compressor 41 during pre-cooling operation above the standard value for medium intensity. The third measure is to increase the rotation speed of the blower 42 during pre-cooling operation above the standard value for medium intensity. By adopting the second and third measures, the freezer compartment temperature can be brought closer to the pre-cooling setting temperature even if the freezer compartment temperature cannot be cooled to the pre-cooling setting temperature within the pre-cooling end time for medium intensity. The fourth measure is to increase the pre-cooling end time above the standard value for medium intensity. By adopting the fourth measure, even if it is not possible to cool the freezer compartment 4 to the pre-cool set temperature within the pre-cool end time in the case of medium strength, a longer time can be secured for cooling the freezer compartment 4.

[0108] Fig. 13 is a diagram illustrating the high-intensity pre-cooling operation of refrigerator 100 according to embodiment 1. In Fig. 13, the upper part shows the change over time in power consumption, and the lower part shows the change over time in freezer compartment temperature. The solid lines indicate the change over time in power consumption and freezer compartment temperature when the pre-cooling intensity is medium, and the dashed lines indicate the change over time in power consumption and freezer compartment temperature when the pre-cooling intensity is high.

[0109] As shown in the upper part of Fig. 13, when the pre-cooling intensity is set to high, the power consumption by the compressor 41 and the blower 42 is greater than when the pre-cooling intensity is medium, and the pre-cooling operation time is longer. As a result, as shown in the lower part of Fig. 13, the freezer compartment temperature at the start of defrosting operation when the pre-cooling intensity is high is lower than the freezer compartment temperature at the start of defrosting operation when the pre-cooling intensity is medium. For this reason, although the estimated defrosting time is longer when the pre-cooling intensity is high than when the pre-cooling intensity is medium, the freezer compartment temperature at the end of defrosting operation when the pre-cooling intensity is high is kept approximately the same as the freezer compartment temperature at the end of defrosting operation when the pre-cooling intensity is medium.

[0110] When the estimated defrosting time is equal to or shorter than the second threshold time, the device control unit 51 weakens the pre-cooling intensity compared to when the estimated defrosting time exceeds the second threshold time. That is, the device control unit 51 changes the pre-cooling intensity from medium to low. The second threshold time is shorter than the first threshold time, e.g., 5 minutes. The pre-cooling intensity is changed from medium to low by selecting at least one of the following means: The first means is to increase the pre-cooling setting temperature above the standard value for medium intensity. The second means is to reduce the rotation speed of the compressor 41 during pre-cooling operation below the standard value for medium intensity. The third means is to reduce the rotation speed of the blower 42 during pre-cooling operation below the standard value for medium intensity. The fourth means is to shorten the pre-cooling end time below the standard value for medium intensity.

[0111] Fig. 14 is a diagram illustrating low-intensity pre-cooling operation of refrigerator 100 according to embodiment 1. In Fig. 14, the upper part shows power consumption over time, and the lower part shows freezer compartment temperature over time. The solid lines indicate the power consumption and freezer compartment temperature over time when the pre-cooling intensity is medium, and the dashed lines indicate the power consumption and freezer compartment temperature over time when the pre-cooling intensity is low.

[0112] As shown in the upper part of Fig. 14, by setting the pre-cooling intensity to low, the power consumption by the compressor 41 and the blower 42 is lower and the pre-cooling operation time is shorter than when the pre-cooling intensity is medium. As a result, as shown in the lower part of Fig. 13, the freezer compartment temperature at the start of defrosting operation when the pre-cooling intensity is low is higher than the freezer compartment temperature at the start of defrosting operation when the pre-cooling intensity is medium. Furthermore, the freezer compartment temperature at the end of defrosting operation when the pre-cooling intensity is low is approximately the same as the freezer compartment temperature at the end of defrosting operation when the pre-cooling intensity is low.

[0113] When the pre-cooling intensity is changed to low intensity, the defrost setting temperature for determining the end of the defrosting operation may be lowered compared to the medium intensity. This is because, when the amount of frost is small, defrosting is performed using the residual heat of the cooler 43, making it less likely that the frost will remain unmelted. This suppresses the temperature rise in the storage compartment and reduces the time that power is supplied to the heater 44, thereby reducing power consumption.

[0114] According to the refrigerator 100 of the first embodiment, the pre-cooling intensity is changed based on the estimated amount of frost. Therefore, the refrigerator 100 of the first embodiment can suppress the temperature rise of food due to defrosting even when the amount of frost is large. Therefore, deterioration of food during the defrosting operation can be suppressed.

[0115] (Variation of Embodiment 1) When the estimated defrost time and the actual defrost time differ from each other, the defrost time calculation unit 52b may correct the conversion model. Specifically, the defrost time calculation unit 52b associates the estimated amount of frost estimated each time a defrosting operation is performed with the estimated defrost time calculated in the conversion model based on the estimated amount of frost, and stores these in the memory unit 53. Furthermore, the defrost time calculation unit 52b measures the actual defrost time each time a defrosting operation is performed, and stores the estimated amount of frost and the actual defrost time during the defrosting operation when the estimated amount of frost was estimated in the memory unit 53.

[0116] FIG. 15 is a diagram illustrating a method for correcting a conversion model according to a modification of the first embodiment. In FIG. 15, points (white circles) corresponding to the estimated frost amount and the actual defrosting time during defrosting operation when the estimated frost amount was estimated are plotted. Also, points (black circles) corresponding to the estimated frost amount and the estimated defrosting time calculated using the conversion model before correction are plotted. In the example shown in FIG. 15, the estimated defrosting time is converted to be shorter than the estimated frost amount. When there is a difference between the estimated defrosting time calculated using the conversion model and the actual defrosting time, a relational expression (approximation) between the estimated frost amount and the estimated defrosting time is generated based on the stored multiple actual defrosting times, as shown by the dashed line, and stored as a new conversion model. A difference between the estimated defrosting time calculated using the conversion model and the actual defrosting time occurs, for example, when the average error between the estimated defrosting time and the actual defrosting time for each estimated frost amount is greater than or equal to a threshold value.

[0117] In order to prevent the conversion model from being updated to a formula that differs significantly due to variations in the estimated amount of frost, the conversion model may be corrected only when there are 10 or more pieces of data on the calculated estimated defrost time and the actual defrost time over an operating period of at least the past two weeks, for example. Furthermore, if the slope of the conversion model before and after correction differs by 10% or more, the conversion model may not be corrected and data on the calculated estimated defrost time and the actual defrost time may continue to be accumulated. Furthermore, the reference estimated amount of frost may be limited to the amount estimated when the pre-cooling intensity is not changed, i.e., when pre-cooling operation is performed at a medium intensity.

[0118] By correcting the conversion model in this way, it is possible to eliminate the discrepancy in the estimated defrosting time calculated using the conversion model before correction. The discrepancy in the estimated defrosting time calculated using the conversion model is due to, for example, individual differences between refrigerators 100, such as minute differences in the gaps between the storage compartment doors, as well as how the user uses the refrigerator, such as the opening angle of refrigerator compartment door 11 and the installation conditions, such as whether there is a wall next to refrigerator 100.

[0119] Embodiment 2 Fig. 16 is a cross-sectional view of a refrigerator 100A according to embodiment 2. As shown in Fig. 16, refrigerator 100A according to embodiment 2 is different from embodiment 1 in that it includes an image capturing device 91 and calculates the occupancy ratio based on an image of the interior of the storage compartment captured by image capturing device 91.

[0120] The camera 91 is provided, for example, on the refrigerator compartment door 11 and periodically captures images of the inside of the refrigerator compartment 1. Hereinafter, an image captured by the camera 91 will be referred to as a captured image. The captured image is a two-dimensional image. Furthermore, multiple camera devices 91 are provided on the refrigerator compartment door 11. The multiple camera devices 91 compensate for blind spots in the capturing range of each camera device 91, thereby capturing images of all stored items in the refrigerator compartment 1. Note that in FIG. 16 , the camera device 91 is provided on the refrigerator compartment door 11 so that it can capture images of the inside of the refrigerator compartment 1, but it may also be provided on other storage compartment doors so that it can capture images of the inside of other storage compartments. However, the camera device 91 may be provided on an interior wall or partition instead of the storage compartment door as long as it can capture images of the inside of the storage compartment.

[0121] FIG. 17 is a functional block diagram of refrigerator 100A according to the second embodiment. As shown in FIG. 17, image capturing device 91 is communicably connected to control device 50 and transmits captured images to control device 50. The calculation unit of control device 50 has estimation unit 52c. Estimation unit 52c calculates the occupancy ratio using an image analysis model Mf learned by so-called artificial intelligence (AI). In other words, estimation unit 52c according to the second embodiment applies a specific value to the occupancy ratio that was used as a representative value in calculating the ventilation rate using function f4 described in the first embodiment.

[0122] The image analysis model Mf uses a known image analysis technique for two-dimensional images to calculate the occupancy ratio, which is output data, for a captured image, which is input data. As described above, the occupancy ratio is the ratio of the volume of the stored item to the volume of the storage compartment. The image analysis model Mf is generated by a supervised learning method using training data consisting of multiple input data representing captured images and correct labels indicating the occupancy ratios corresponding to the input data. The training data is prepared through experiments using refrigerators of the same type as refrigerator 100A. The learning algorithm may be deep learning, which learns to extract features themselves, or other known methods such as genetic programming, functional logic programming, or support vector machines.

[0123] Specifically, differences from the first embodiment in the calculation of the ventilation amount will be described. First, differences from the first embodiment in the calculation of the amount of frost formed when the door is opened will be described. The estimation unit 52c calculates the ventilation amount M per opening / closing operation during recovery operation or temperature adjustment operation. ｖ In calculating the ventilation volume M, the image captured by the image capture device 91 immediately after the refrigerator compartment door 11 is closed is input to the image analysis model Mf. The image analysis model Mf estimates the occupancy ratio of the storage compartment by the stored items by inputting the captured image received from the image capture device 91. The estimation unit 52c acquires the occupancy ratio estimated by the image analysis model Mf and transmits it to the frost amount calculation unit 52a. The frost amount calculation unit 52a calculates the ventilation volume M based on the occupancy ratio estimated by the estimation unit 52c. ｖ That is, the frost amount calculation unit 52a sets the coefficients a and b corresponding to the occupancy rate estimated by the estimation unit 52c in the function f4, and calculates the ventilation amount M ｖ The amount of frost formed on the other storage compartment doors when they are opened and closed once is calculated. ｖ The method for calculating the amount of frost formed when the door is opened and before the pre-cooling operation is started is the same as in the first embodiment.

[0124] Next, differences from the first embodiment regarding the calculation of the amount of pre-cool frost formation will be described. ｖ，ｐIn calculating the ventilation volume M, the captured image received from the photographing device 91 is finally input to the image analysis model Mf. The image analysis model Mf estimates the occupancy ratio of the storage item to the storage compartment by inputting the captured image received from the photographing device 91. The estimation unit 52c acquires the occupancy ratio estimated by the image analysis model Mf and transmits it to the frost amount calculation unit 52a. The frost amount calculation unit 52a calculates the ventilation volume M based on the occupancy ratio estimated by the estimation unit 52c. ｖ，ｐ That is, the frost amount calculation unit 52a sets the coefficients a and b corresponding to the occupancy rate estimated by the estimation unit 52c in the function f4, and calculates the ventilation amount M ｖ，ｐ The amount of frost expected by opening and closing the storage compartment door once during other pre-cooling operations is calculated. ｖ，ｐ The method for calculating the amount of pre-cool frost is the same as in the first embodiment.

[0125] Also, similar to embodiment 1, the calculation unit 52 calculates the estimated amount of frost by summing the amount of frost formed when the door is closed, the amount of frost formed when the door is open, and the amount of frost formed in the pre-cooling mode, and estimates the estimated defrosting time based on the estimated amount of frost. Also similar to embodiment 1, the device control unit 51 adjusts the pre-cooling strength based on the estimated defrosting time estimated by the calculation unit 52. The memory unit 53 stores an image analysis model Mf.

[0126] The effects of the second embodiment will be described. For example, if the capacity of the refrigerator compartment 1 is 250 L, a maximum of 250 L of air may be exchanged when the refrigerator compartment door 11 is opened or closed. Here, if the occupancy rate is 80%, the amount of exchanged air is limited to a maximum of about 50 L. In this way, the occupancy rate plays a major role in determining the ventilation rate. In the second embodiment, the ventilation rate is calculated by setting coefficients a and b corresponding to the occupancy rate estimated based on the captured image in function f4, so that the amount of frost formation can be calculated with high accuracy.

[0127] In the first and second embodiments, the amount of frost is calculated by inputting each parameter into the formulas (1) to (8). In the third embodiment, each parameter is used to calculate the amount of frost when the door is opened Δm ｖThe present embodiment differs from the first and second embodiments in that the door opening frost amount and the pre-cooling frost amount are estimated by inputting the door opening frost amount and the pre-cooling frost amount into a trained model for calculating the door opening frost amount and the pre-cooling frost amount. The following mainly describes the differences from the first and second embodiments.

[0128] Fig. 18 is a functional block diagram of a refrigerator 100B according to the third embodiment. As shown in Fig. 18, the calculation unit of the control device 50 has a frost amount estimation unit 52d. The frost amount estimation unit 52d estimates the door-open frost amount Δm using a first trained model M1 trained by so-called artificial intelligence. ｖ The frost amount estimation unit 52d also calculates the pre-cool frost amount using a second trained model M2 trained by so-called artificial intelligence.

[0129] The first trained model M1 is the input data of the outside temperature T ｏｕｔ , outside humidity H ｏｕｔ , type of storage room, door opening time t ｏｐｅｎ , and the amount of frost formed on the door when it is opened, which is output data for the captured image, Δm ｖ The trained model is generated by a supervised learning method using training data including a plurality of input data and ground truth labels indicating the amount of frost formation when the door is opened, corresponding to the input data. The training data is prepared through experiments using refrigerators of the same type as refrigerator 100B.

[0130] The frost amount estimation unit 52d estimates the outside temperature T ｏｕｔ , outside humidity H ｏｕｔ , type of storage room, door opening time t ｏｐｅｎ , and the captured image is input to the first trained model M1, and the amount of frost formation on the door when it is opened Δm ｖ The amount of frost formed when the door is opened Δm ｖ The calculation timing and parameters themselves are the same as those in the first and second embodiments.

[0131] The second trained model M2 is the input data of the outside temperature T ｏｕｔ , outside humidity H ｏｕｔ , compressor representative rotation speed n ｃ，ｐ , blower representative rotation n ｆ，ｐ , pre-cool representative time tｐ The amount of pre-cool frost formation, which becomes output data, is calculated for the total number of times the storage compartment door is opened and closed during the calculation period, the total opening and closing time, the length of the calculation period, and the captured images. The trained model is generated by a supervised learning method using training data consisting of multiple pieces of input data and correct labels indicating the amount of pre-cool frost formation corresponding to the input data. The training data is prepared through experiments using refrigerators of the same type as refrigerator 100B.

[0132] When the defrost signal is output, the frost amount estimation unit 52d estimates the outside temperature T ｏｕｔ , outside humidity H ｏｕｔ , compressor representative rotation speed n ｃ，ｐ , blower representative rotation n ｆ，ｐ , pre-cool representative time t ｐ The total number of times the storage chamber door is opened and closed during the calculation period, the total opening and closing time, the length of the calculation period, and the captured images are input to the second trained model M2 to obtain the pre-cool frost amount, which is output data from the second trained model M2. The calculation timing and parameters for the pre-cool frost amount are the same as those in the first and second embodiments.

[0133] Also, similar to embodiment 1, the calculation unit 52 calculates the estimated frost amount by summing the closed door frost amount, the open door frost amount, and the pre-cool frost amount, and estimates the estimated defrosting time based on the estimated frost amount. Also similar to embodiment 1, the device control unit 51 adjusts the pre-cooling intensity based on the estimated defrosting time estimated by the calculation unit 52. The memory unit 53 stores a first trained model M1 and a second trained model M2.

[0134] The effects of embodiment 3 will be described. Generally, when there are multiple parameters including an image captured by the imaging device 91, accurate results may not be obtained even when a formula for calculating the amount of frost is determined based on rules. According to embodiment 3, by using the first trained model M1 and the second trained model M2, the amount of frost can be calculated accurately even when there are multiple parameters.

[0135] The above is a description of the embodiments of the present disclosure, but the present disclosure is not limited to the configurations of the above embodiments, and various modifications are possible within the scope of the technical concept thereof.

[0136] In the first embodiment, the pre-cooling termination condition is described as one condition that the freezer compartment temperature is equal to or lower than the pre-cooling set temperature. However, the pre-cooling termination condition may also be that the temperature of a storage compartment other than the freezer compartment 4 is equal to or lower than the pre-cooling set temperature. In this case, the pre-cooling set temperature of the storage compartment is a temperature lower than the set temperature in the temperature adjustment operation.

[0137] In the first embodiment, the estimated amount of frost is calculated by adding up the amount of frost formed when the door is closed, the amount of frost formed when the door is open, and the amount of frost formed when the door is pre-cooled. However, the amount of frost may be calculated by adding up a constant determined in advance through experiments, for example.

[0138] In the first embodiment, the case where the pre-cooling intensity is in three stages has been described as an example, but the pre-cooling intensity may be in two stages or four or more stages.

[0139] In the first embodiment, the precooling intensity is determined based on the estimated defrosting time. However, the precooling intensity may be determined based on the estimated amount of frost corresponding to the estimated defrosting time. In this case, instead of the first and second threshold times set for the estimated defrosting time, the precooling intensity is determined based on the first and second threshold times set for the estimated amount of frost. For example, when the estimated amount of frost is equal to or greater than the first threshold, the device control unit 51 increases the precooling intensity. That is, the precooling intensity is changed from medium to high. Furthermore, when the estimated amount of frost is greater than the second threshold, the device control unit 51 decreases the precooling intensity. That is, the precooling intensity is changed from medium to low. The second threshold is a value smaller than the first threshold. Here, the first and second threshold times set for the estimated defrosting time correspond to the first and second threshold times set for the estimated amount of frost. Therefore, when the estimated amount of frost is equal to or greater than the first threshold, the estimated defrosting time is also equal to or greater than the first threshold. Similarly, when the estimated amount of frost is equal to or less than the second threshold, the estimated defrosting time is also equal to or less than the second threshold.

[0140] 1 Refrigerator compartment, 2 Ice making compartment, 3 Switching compartment, 4 Freezer compartment, 5 Vegetable compartment, 7 Machine compartment, 8 Cooler compartment, 10 Main body, 11 Refrigerator compartment door, 12 Ice making compartment door, 13 Switching compartment door, 14 Freezer compartment door, 15 Vegetable compartment door, 20 Storage compartment open / close sensor, 21 Refrigerator compartment open / close sensor, 23 Switching compartment open / close sensor, 24 Freezer compartment open / close sensor, 25 Vegetable compartment open / close sensor, 30 Storage compartment temperature sensor, 31 Refrigerator compartment temperature sensor, 33 Switching compartment temperature sensor, 34 Freezer compartment temperature sensor, 35 Vegetable compartment temperature sensor, 37 Cooler temperature sensor, 40 Storage compartment damper, 41 Compressor, 42 Fan, 43 Cooler, 44 Heater, 45 Refrigerator compartment damper, 46 Switching compartment damper, 50 Control device, 51 Equipment control unit, 52 Calculation unit, 52a Frost amount calculation unit, 52b defrosting time calculation unit, 52c estimation unit, 52d frost amount estimation unit, 53 memory unit, 61, 62, 63 partition, 64 shelf, 71, 72, 73 storage case, 81 outside refrigerator temperature sensor, 82 outside refrigerator humidity sensor, 91 imaging device, 100, 100A, 100B refrigerator, 101 processing circuit, 102 processor, 103 memory, 104 bus.

Claims

1. A refrigerator comprising: a cooler that cools the air by exchanging heat between a refrigerant flowing therein and the air; a main body having a storage chamber in which stored items are stored and a cooler chamber in which the cooler is provided; a blower that sends the air to the storage chamber; a compressor that compresses the refrigerant; a heater that heats the cooler; and a control device that controls the compressor, the blower, and the heater, wherein the control device sequentially executes a temperature adjustment operation that controls the compressor and the blower to adjust the temperature of the storage chamber to a set temperature; a pre-cool operation that controls the compressor and the blower to adjust the temperature of the storage chamber to a pre-cool set temperature which is lower than the set temperature; and a defrost operation that controls the heater to remove frost that has adhered to the cooler, and changes at least one of the compressor rotation speed, the blower rotation speed, and the pre-cool set temperature during the pre-cool operation based on an estimated amount of frost that has formed on the cooler before the defrost operation is started.

2. The refrigerator as described in claim 1, further comprising a storage compartment door provided in front of the storage compartment, wherein the estimated amount of frost includes at least one of a closed door frost amount indicating the amount of frost adhering to the cooler when the storage compartment door is closed, an open door frost amount indicating the amount of frost adhering to the cooler when the storage compartment door is open, and a pre-cool frost amount indicating the expected amount of frost adhering to the cooler during the pre-cool operation.

3. The refrigerator according to claim 2, further comprising an outside temperature sensor that measures an outside temperature, which is the temperature of the space outside the refrigerator in which the refrigerator is placed, and an outside humidity sensor that measures an outside humidity, which is the humidity of the space outside the refrigerator, wherein the control device determines the amount of frost formation on the closed door based on the compressor rotation speed, the blower rotation speed, the outside temperature, and the outside humidity.

4. The refrigerator according to claim 3, wherein the control device calculates the amount of frost formed on the door each time a predetermined door closing calculation time has elapsed.

5. The refrigerator according to claim 3 or 4, wherein the control device estimates the amount of frost formed on the door when the door is closed while the compressor is operating.

6. The refrigerator as described in claim 2, further comprising an outside temperature sensor that measures an outside temperature, which is the temperature of the space outside the refrigerator in which the refrigerator is placed, an outside humidity sensor that measures an outside humidity, which is the humidity of the space outside the refrigerator, and a storage chamber opening / closing sensor that detects opening and closing of the storage chamber door, wherein the control device estimates the amount of frost formation on the door when it is opened based on the outside temperature, the outside humidity, the number of times the storage chamber door is opened and closed, and the time the storage chamber door is open.

7. The refrigerator according to claim 6, wherein the control device estimates the amount of frost formed when the door is opened each time the storage compartment door is opened or closed.

8. The refrigerator according to claim 6 or 7, further comprising an imaging device for photographing the inside of the storage compartment, wherein the control device stores an image analysis model, wherein the image analysis model estimates the occupancy ratio of the stored items to the storage compartment by inputting the photographed image received from the imaging device, and wherein the control device estimates the amount of frost formation on the door when it is opened based on the occupancy ratio estimated by the image analysis model.

9. The refrigerator as described in claim 6 or 7, further comprising an imaging device that captures images of the inside of the storage compartment, wherein the control device stores a first trained model, and the first trained model estimates the amount of frost formation on the door when it is opened by inputting the captured image received from the imaging device, the outside temperature, the outside humidity, the number of times the door is opened and closed, and the time the door is opened, and the control device estimates the amount of frost formation on the door when it is opened using the first trained model.

10. The refrigerator according to claim 2, further comprising an outside temperature sensor that measures an outside temperature, which is the temperature of the space outside the refrigerator in which the refrigerator is placed, an outside humidity sensor that measures an outside humidity, which is the humidity of the space outside the refrigerator, and a storage chamber opening / closing sensor that detects opening and closing of the storage chamber door, wherein the control device estimates the amount of pre-cool frost based on a predetermined representative rotation speed of the compressor, a predetermined representative rotation speed of the blower, the outside temperature, the outside humidity, a predetermined representative time of the pre-cool operation, a total number of openings and closings and a total opening and closing time of the storage chamber door during a past calculation period, and a length of the calculation period.

11. The refrigerator according to claim 10, further comprising an imaging device for photographing the inside of the storage compartment, wherein the control device stores an image analysis model, wherein the image analysis model estimates the occupancy ratio of the stored items to the storage compartment by inputting the photographed image received from the imaging device, and wherein the control device estimates the amount of pre-cool frost based on the occupancy ratio estimated by the image analysis model.

12. The refrigerator as described in claim 10, further comprising an imaging device that captures images of the inside of the storage compartment, wherein the control device stores a second trained model, and the second trained model estimates the amount of pre-cool frost based on the captured images received from the imaging device, the representative rotation speed of the compressor, the representative rotation speed of the blower, the outside temperature, the outside humidity, the representative time of the pre-cool operation, the total number of times and the total opening and closing time of the storage compartment door during the past calculation period, and the length of the calculation period, and the control device estimates the amount of pre-cool frost using the second trained model.

13. A refrigerator as claimed in any one of claims 1 to 12, wherein the control device increases the rotation speed of the compressor when the estimated amount of frost is equal to or greater than a first threshold value, compared to when the estimated amount of frost is less than the first threshold value.

14. A refrigerator as claimed in any one of claims 1 to 12, wherein the control device increases the rotation speed of the blower when the estimated amount of frost is equal to or greater than a first threshold value compared to when the estimated amount of frost is less than the first threshold value.

15. A refrigerator as claimed in any one of claims 1 to 12, wherein the control device sets the pre-cool setting temperature lower when the estimated amount of frost is equal to or greater than a first threshold value than when the estimated amount of frost is less than the first threshold value.

16. A refrigerator as claimed in any one of claims 1 to 15, wherein when the estimated amount of frost is equal to or less than a second threshold value which is smaller than the first threshold value, the control device reduces the rotation speed of the compressor, increases the rotation speed of the blower, or raises the pre-cool setting temperature compared to when the estimated amount of frost exceeds the second threshold value.

17. A refrigerator as claimed in any one of claims 1 to 15, wherein the control device increases the rotation speed of the blower when the estimated amount of frost is equal to or less than a second threshold value which is smaller than the first threshold value, compared to when the estimated amount of frost is greater than the second threshold value.

18. A refrigerator as claimed in any one of claims 1 to 15, wherein the control device sets the pre-cool setting temperature higher when the estimated amount of frost is equal to or less than a second threshold value which is smaller than the first threshold value than when the estimated amount of frost is greater than the second threshold value.

19. The refrigerator according to any one of claims 1 to 18, wherein the control device changes a pre-cool end time indicating an upper limit of time during which the pre-cool operation can be performed based on the estimated amount of frost.

20. A refrigerator as claimed in any one of claims 1 to 19, further comprising a cooler temperature sensor for measuring the temperature of the cooler, wherein the control device terminates the defrosting operation when the temperature of the cooler becomes equal to or higher than a defrost setting temperature, and changes the defrost setting temperature based on the estimated amount of frost.

21. The refrigerator described in any one of claims 1 to 20, wherein the control device uses a conversion model to convert the estimated amount of frost into an estimated defrosting time required to complete the defrosting operation, and corrects the conversion model when there is a discrepancy between the estimated defrosting time and the actual defrosting time.

22. A control device comprising: a calculation unit that calculates an amount of frost formation when the door is opened, which indicates the amount of frost that has adhered to a cooler when the storage compartment door of a refrigerator performing a defrosting operation is in an open state; and a memory unit that stores a first trained model that estimates the amount of frost formation when the door is opened by inputting an outside temperature that is the temperature of the space outside the refrigerator in which the refrigerator is placed, an outside humidity that is the humidity of the space outside the refrigerator, a type of storage compartment of the refrigerator, a time when the storage compartment door is opened, and an image taken inside the storage compartment, wherein the calculation unit estimates the amount of frost formation when the door is opened using the first trained model.

23. The control device described in claim 22, wherein the calculation unit controls the compressor and blower of the refrigerator to calculate a pre-cool frost amount indicating the expected amount of frost that will adhere to the cooler during pre-cool operation in which the temperature of the storage compartment is adjusted to a pre-cool set temperature lower than the set temperature, and the memory unit stores a second trained model that estimates the pre-cool frost amount by inputting the outside temperature, the outside humidity, a predetermined representative rotation speed of the compressor, a predetermined representative rotation speed of the blower, a predetermined representative pre-cool time, a total number of times and a total opening and closing time of the storage compartment door in a past calculation period, the length of the calculation period, and the captured images, and the calculation unit estimates the pre-cool frost amount using the second trained model.

Images