Storehouse

Abstract

This storehouse comprises: a body that includes a storage chamber and a cooler chamber; a door that is provided in the front surface of the storage chamber; a cooler that is disposed in the cooler chamber and generates cold air by exchanging heat with a refrigerant; a blower that feeds cold air to the storage chamber; a compressor that feeds the refrigerant to the cooler; an internal temperature sensor that measures the internal temperature, which is the temperature in the storage chamber; and a control device that controls the compressor and the blower. The control device stops the compressor and the blower, and executes a defrosting operation for defrosting the cooler as well as a first post-defrost operation that is a cooling operation for after the defrosting operation has been completed. In the first post-defrost operation, the control device determines an initial setting rank on the basis of the outside air temperature and a rank indicating the heat load quantity in the storage chamber, activates at least one of the compressor and the blower at the rotation speed set for the initial setting rank, increases the setting rank every time a preset rank-increase period elapses, and gradually increases the rotation speed of at least one of the compressor and the blower.

Description

storage facility

[0001] The present disclosure relates to a storage facility for cooling and storing stored items such as food.

[0002] In recent years, with changes in lifestyles due to an increase in dual-income households and single-person households, there has been a growing tendency to buy large amounts of food at once and store them in storage facilities such as refrigerators or freezers. As a result, there is a demand for storage facilities with larger capacities as well as storage facilities that can precisely adjust temperatures to store food at temperatures suitable for each ingredient.

[0003] The storage facility is also provided with a cooler that generates cold air for cooling objects. The cooler has a plurality of heat transfer tubes arranged perpendicular to the air flow and a plurality of fins attached to the outer surfaces of the heat transfer tubes and arranged in parallel at regular intervals. The cooler acts as an evaporator in a vapor compression refrigeration cycle and cools the air circulating inside the storage facility. Specifically, in the cooler, heat is exchanged between the refrigerant flowing inside the heat transfer tubes and the air flowing through the air passage via the tube walls and fins of the heat transfer tubes, and the air is cooled by the evaporation of the refrigerant.

[0004] When air is cooled by heat exchange with a refrigerant, the moisture in the air is cooled. As the moisture cools, it condenses and adheres to the surfaces of the fins, forming frost. Frost on the fins increases air flow resistance, reducing airflow, and increases the thermal resistance of the fins, impeding heat exchange and reducing the cooling efficiency of the cooler. To melt and remove frost that has adhered to the fins of the cooler, an electric heater, for example, is provided, and a defrosting operation is performed at regular intervals to melt the frost by energizing the heater.

[0005] One of the known degradation phenomena of stored items in a storage facility is the freeze-drying phenomenon (so-called freezer burn), in which moisture evaporates from the stored items and they dry out. The freeze-drying phenomenon occurs due to the difference between the temperature of the stored items after a defrosting operation and the ambient temperature of the stored items. Specifically, during normal cooling operation, the temperature of the stored items and the ambient temperature are maintained the same. When a defrosting operation is subsequently performed, the cooler is heated by the heater, and the storage compartment is not cooled, so the temperature of the stored items and the ambient temperature of the stored items increase. When the defrosting operation is then terminated and the cooling operation is initiated, the ambient temperature of the stored items drops first, followed by a delayed drop in the temperature of the stored items. This time difference creates a temperature difference between the stored items and their ambient temperature, causing moisture in the stored items to evaporate and the stored items to dry out.

[0006] Therefore, as a technology for suppressing the freeze-drying phenomenon and improving the preservation quality of food, for example, Patent Document 1 proposes rotating the blower fan in the reverse direction for a predetermined period of time after defrosting operation to reduce the temperature difference between the air temperature inside the packaging material and the surface of the food.

[0007] Japanese Patent Application Laid-Open No. 2006-105406

[0008] However, in the refrigerator of Patent Document 1, the blower fan is rotated in the reverse direction to perform cooling operation immediately after the defrosting operation, which results in the warm air immediately after the defrosting operation being flowed into the freezer compartment through the return air duct of the freezer compartment. This does not lead to suppression of the amount of warm air flowing into the freezer compartment as a whole, and a large temperature difference occurs between the food and the ambient air temperature, so there is room for improvement in suppressing food deterioration due to the freeze-drying phenomenon.

[0009] The present disclosure is intended to solve the above-mentioned problems and aims to suppress deterioration of stored items in a storage facility that cools the stored items.

[0010] The storage cabinet of the present disclosure comprises a main body having a storage chamber and a cooler chamber, a door provided on the front of the storage chamber, a cooler disposed in the cooler chamber and generating cool air by heat exchange with a refrigerant, a blower that sends the cool air to the storage chamber, a compressor that sends the refrigerant to the cooler, an internal temperature sensor that measures the internal temperature of the storage chamber, which is the temperature of the storage chamber, and a control device that controls the compressor and blower, wherein the control device stops the compressor and blower and performs a defrosting operation to defrost the cooler, and an initial post-defrost operation that is the first cooling operation after the defrosting operation is completed, and during the initial post-defrost operation, the control device determines an initial setting rank based on the outside air temperature and a rank that represents the amount of heat load in the storage chamber, starts at least one of the compressor and blower at a rotation speed set by the initial setting rank, and increases the setting rank every time a preset rank-up time elapses, thereby gradually increasing the rotation speed of at least one of the compressor and blower.

[0011] According to the storage facility of the present disclosure, during the first operation after defrosting, deterioration of the stored items in the storage facility can be suppressed by gradually increasing the rotation speed of at least one of the compressor and the blower using a set rank based on the outside air temperature and a rank representing the amount of heat load in the storage compartment.

[0012] Fig. 1 is a front view of a refrigerator according to embodiment 1. Fig. 2 is a schematic cross-sectional view of a refrigerator according to embodiment 1. Fig. 3 is a schematic cross-sectional view of a refrigerator according to embodiment 1. Fig. 4 is a schematic view of a cooling mechanism of a refrigerator according to embodiment 1. Fig. 5 is a schematic view showing a structure inside a cooler compartment of a refrigerator according to embodiment 1. Fig. 6 is a control block diagram of a refrigerator according to embodiment 1. Fig. 7 is a second adjustment coefficient β calculated by an adjustment coefficient calculation unit according to embodiment 1. Ｒ and β Ｆ1 is an example of a refrigerator control device according to embodiment 1. FIG. 2 is a diagram illustrating an example of a hardware configuration of a refrigerator control device according to embodiment 1. FIG. 3 is a diagram illustrating another example of a hardware configuration of a refrigerator control device according to embodiment 1. FIG. 4 is a diagram illustrating the operation and internal temperature of a refrigerator according to the prior art. FIG. 5 is a diagram illustrating the mechanism by which the freeze-drying phenomenon occurs in the prior art. FIG. 6 is a diagram illustrating the operation and internal temperature of a refrigerator according to embodiment 1. FIG. 7 is a flowchart illustrating the operation of a refrigerator according to embodiment 1. FIG. 8 is a diagram illustrating a change in freezing compartment temperature Tf when the freezing compartment door is opened and closed in embodiment 1. Ｆ 1 is a flowchart showing a method for calculating a temperature rise value and a recovery time when the door is opened and closed in embodiment 1. FIG. 2 is a flowchart showing a method for measuring a recovery time when the door is opened and closed in embodiment 1. FIG. 3 is a flowchart showing a flow of the first operation after defrosting in embodiment 1. FIG. 4 is an example of a table showing set ranks according to the usage frequency rank and the outdoor air rank at the time of the first operation after defrosting in embodiment 1. FIG. 5 is an example of a map of control parameters for each set rank at the time of the first operation after defrosting in embodiment 1. FIG. 6 is a diagram explaining the angle θ of the damper in embodiment 1. FIG. 7 is a diagram showing the relationship between the temperature of stored items in the freezer compartment and the ambient temperature before and after a defrosting operation in the prior art. FIG. 8 is a diagram showing the relationship between the temperature of stored items in the freezer compartment and the ambient temperature before and after a defrosting operation in embodiment 1. FIG. 9 is a flowchart showing the operation of a refrigerator according to embodiment 2. FIG. 10 is an example of a table showing set ranks according to the temperature rise rank and the outdoor air rank at the time of a defrosting operation in embodiment 2. FIG. 11 is a schematic cross-sectional view of a refrigerator according to embodiment 3. FIG. 12 is a flowchart showing a flow of the first operation after defrosting in embodiment 3.

[0013] A refrigerator 1 having a refrigerator compartment 11 and a freezer compartment 12 will be described below with reference to the drawings as an embodiment of a storage cabinet according to the present disclosure. In each drawing, identical reference numerals denote identical or equivalent components, and this is common throughout the specification. Other processes may be included between the steps of the flowcharts of the present disclosure. In each drawing, the relative dimensions or shapes of the components may differ from those in actuality.

[0014] Embodiment 1. <Configuration of Refrigerator 1> FIG. 1 is a front view of refrigerator 1 according to embodiment 1. FIGS. 2 and 3 are cross-sectional schematic views of refrigerator 1 according to embodiment 1. FIG. 2 is a view of refrigerator 1 shown in FIG. 1 cut along line A-A and viewed from the direction of the arrows, and FIG. 3 is a view of refrigerator 1 shown in FIG. 1 cut along line B-B and viewed from the direction of the arrows. In the following description, to facilitate understanding, terms indicating directions, such as "up," "down," "right," "left," "front," "this side," "rear," and "back," are used as appropriate. However, these terms are for explanatory purposes only and do not limit the embodiments. In addition, in the description of the embodiment, "up," "down," "right," "left," "front," "this side," "rear," and "back" are used when refrigerator 1 is in use and viewed from the front.

[0015] As shown in Figures 1 and 2, refrigerator 1 includes a main body 2 having an opening at the front and multiple storage compartments formed therein. Main body 2 includes a steel outer box 21, a resin inner box 22, and a heat insulating member 23 filling the space between outer box 21 and inner box 22. Outer box 21 is made of a metal such as steel and has an opening at the front. Inner box 22 is made of resin and is fitted into outer box 21 through the opening. Heat insulating member 23 is made of, for example, urethane foam or vacuum insulation material, and fills the space between outer box 21 and inner box 22. The storage space formed inside main body 2 is divided into multiple storage compartments for storing food by partition members with heat insulating properties.

[0016] The refrigerator 1 has multiple storage compartments, including a refrigerator compartment 11 set to a refrigeration temperature range (e.g., approximately 3 to 6°C) and a freezer compartment 12 located below the refrigerator compartment 11 and set to a freezing temperature range below 0°C (e.g., -18°C). In the following description, either or both of the refrigerator compartment 11 and the freezer compartment 12 may be collectively referred to as the "storage compartment." The refrigerator 1 may further include, as storage compartments, an ice-making compartment set to a temperature of, for example, -18°C, a switchable compartment whose set temperature can be switched between the refrigerator temperature range and the freezer temperature range, or a vegetable compartment set to a temperature of, for example, 6°C.

[0017] The refrigerator compartment 11 is provided with a plurality of shelves 111 on which stored items such as food are placed, and a storage container 112 for storing the stored items. The freezer compartment 12 is provided with a plurality of storage containers 122 for storing the stored items. The shelves 111 are, for example, glass shelves. The storage containers 112 and 122 are, for example, sliding cases that can be pulled out forward. The storage containers 112 and 122 are supported by case frames (not shown) provided on the left and right inner wall surfaces of the refrigerator compartment 11 and the freezer compartment 12, and are configured to slide back and forth independently of the opening and closing of the refrigerator compartment door 110 and the freezer compartment door 120.

[0018] An opening formed on the front surface of the refrigerator compartment 11 is provided with a single-wing refrigerator compartment door 110 that opens and closes the opening. The refrigerator compartment door 110 is attached to the main body 2 via a hinge provided on the main body 2. The freezer compartment 12 is configured to be opened and closed by a drawer-type freezer compartment door 120. Note that the configurations of the refrigerator compartment door 110 and the freezer compartment door 120 are not limited to the examples shown in Figures 1 and 2. For example, the refrigerator compartment door 110 may be a double-wing door or a drawer-type door, and the freezer compartment door 120 may be a single-wing door or a double-wing door.

[0019] The refrigerator compartment 11 and the freezer compartment 12 are separated by a heat-insulating partition member 16. The partition member 16 is provided with an opening / closing sensor 17 that detects the opening and closing of the refrigerator compartment door 110 and the freezer compartment door 120, respectively.

[0020] The open / close sensor 17 includes an actuating unit provided on the rear side of the refrigerator compartment door 110 and the freezer compartment door 120 and a detecting unit provided on the partition member 16. The detecting unit is, for example, a magnetic sensor such as a reed switch or a low-current Hall IC operating at 48 V or less. The actuating unit activates the detecting unit when brought close to the detecting unit, and is, for example, a magnet. The open / close sensor 17 may also be configured as a single unit such as a push button switch. Configuring the detecting unit of the open / close sensor 17 as a parallel circuit makes it possible to determine whether the refrigerator compartment door 110 or the freezer compartment door 120 is open, or whether both doors are open. In this embodiment, the open / close sensor 17 transmits an open signal to the control device 6 when at least one of the refrigerator compartment door 110 and the freezer compartment door 120 is opened. That is, in this embodiment, a state in which at least one of the refrigerator compartment door 110 and the freezer compartment door 120 is open is referred to as an open state, and a state in which both the refrigerator compartment door 110 and the freezer compartment door 120 are closed is referred to as a closed state.

[0021] An operation display unit 18 is provided on the outer surface of the refrigerator compartment door 110. The operation display unit 18 includes an operation unit 18a that accepts operations from the user, and a display unit 18b that displays temperature information, inventory information, and notifications for the user for the refrigerator compartment 11 and the freezer compartment 12. The operation unit 18a has multiple operation buttons, and the user can set the temperatures of the refrigerator compartment 11 and the freezer compartment 12 by operating the operation unit 18a. The display unit 18b is, for example, a liquid crystal display. The operation display unit 18 may be configured as a touch panel in which the operation unit 18a is integrally formed on the display unit 18b.

[0022] An outside air temperature sensor 19 is provided inside the operation display unit 18 to measure an outside air temperature Ta, which is the temperature of the space outside the refrigerator compartment 11 and the freezer compartment 12 separated by the freezer compartment door 120. The outside air temperature sensor 19 is, for example, a thermistor. The outside air temperature Ta measured by the outside air temperature sensor 19 is output to the control device 6.

[0023] A control device 6 that controls each part of the refrigerator 1 is provided on the rear side of the upper part of the refrigerator 1. Based on input from the operation unit 18a and output from each sensor, the control device 6 controls the cooling mechanism and each heater, which will be described later, to perform a cooling operation that cools the refrigerator compartment 11 and the freezer compartment 12, and a defrosting operation that defrosts the cooler 34. The configuration and control of the control device 6 will be described in detail later.

[0024] A cooling mechanism that supplies cold air is provided on the rear side of refrigerator compartment 11 and freezer compartment 12. Fig. 4 is a schematic diagram of the cooling mechanism of refrigerator 1 according to embodiment 1. As shown in Fig. 4, refrigerator 1 includes a compressor 31, a condenser 32, a pressure reducing device 33, a cooler 34, and a blower 35 as the cooling mechanism that supplies cold air. Compressor 31, condenser 32, pressure reducing device 33, and cooler 34 are connected by refrigerant pipes to form a refrigerant circuit. Solid arrows in Fig. 4 indicate the direction in which the refrigerant circulates in the refrigerant circuit.

[0025] The compressor 31 compresses the refrigerant to a high-temperature, high-pressure gaseous state. As shown in FIG. 2 , the compressor 31 is disposed in a machine room 30 provided below the cooler room 3 on the rear side of the main body 2 of the refrigerator 1. The high-temperature, high-pressure refrigerant flowing out of the compressor 31 flows into the condenser 32. The condenser 32 dissipates heat from the refrigerant flowing in from the compressor 31 to condense the refrigerant. The condenser 32 is, for example, a fin-and-tube heat exchanger.

[0026] The refrigerant condensed in the condenser 32 flows into the pressure reducing device 33. The pressure reducing device 33 reduces the pressure of the refrigerant flowing in from the condenser 32 to a two-phase state of liquid and gas. The pressure reducing device 33 is, for example, a capillary tube. The two-phase refrigerant of liquid and gas that flows out of the pressure reducing device 33 flows into the cooler 34. In other words, the compressor 31 sends the refrigerant to the cooler 34 via the condenser 32 and the pressure reducing device 33.

[0027] The cooler 34 evaporates the two-phase refrigerant decompressed by the pressure reducing device 33, and cools the air around the cooler 34 by the heat absorption effect caused by the evaporation of the refrigerant. That is, the cooler 34 functions as an evaporator in the refrigerant circuit. The cooler 34 is, for example, a fin-and-tube heat exchanger. The refrigerant flowing out of the cooler 34 returns to the compressor 31. By repeating this cycle, the cooler 34 generates cold air.

[0028] The cool air generated by the cooler 34 is sent to the refrigerator compartment 11 and the freezer compartment 12 by the blower 35. The blower 35 is, for example, an axial flow fan. The rotation speed of the blower 35 is controlled by the control device 6.

[0029] FIG. 5 is a schematic diagram showing the structure inside the cooler compartment 3 of the refrigerator 1 according to the first embodiment. The dashed arrow in FIG. 5 indicates the air flow direction D1 in the cooler compartment 3. The cooler 34 disposed in the cooler compartment 3 generates cold air by heat exchange with the refrigerant. The cooler 34 includes a plurality of heat transfer tubes 342 each having a smooth surface and a plurality of thin plate-like fins 341, and a plurality of U-shaped connecting tubes 343. The heat transfer tubes 342 are arranged vertically. For example, six heat transfer tubes 342 are arranged vertically. Two adjacent heat transfer tubes 342 are connected at one end in the left-right direction by the connecting tube 343. This forms a continuous refrigerant tube.

[0030] The refrigerant flowing through the refrigerant pipes of the cooler 34 flows from an inlet 34a connected to the lowest heat transfer pipe 342 to an outlet 34b connected to the highest heat transfer pipe 342. Air in the cooler chamber 3 flows in a direction D1 from below to above the cooler 34 by an air blower 35 provided at the top of the cooler chamber 3. Therefore, the lowest heat transfer pipe 342 is disposed on the most upstream side of the multiple heat transfer pipes 342 with respect to the air flow direction D1. Furthermore, the uppermost heat transfer pipe 342 is disposed on the most downstream side of the multiple heat transfer pipes 342 with respect to the air flow direction D1.

[0031] The low-temperature refrigerant in a gas-liquid two-phase state flowing in from the pressure reducing device 33 flows from the inlet 34a of the cooler 34 through the heat transfer tube 342 located furthest upstream relative to the air flow direction D1, and then flows through the heat transfer tubes 342 located gradually downstream to reach the outlet 34b of the cooler 34. As the two-phase refrigerant flowing through the cooler 34 moves from the inlet 34a to the outlet 34b of the cooler 34, it exchanges heat with the air flowing outside the heat transfer tube 342. As a result, the two-phase refrigerant flows through the heat transfer tube 342 while the liquid phase in the refrigerant evaporates. Normally, the temperature of the refrigerant at the inlet 34a of the cooler 34 is lower than the temperature of the refrigerant at the outlet 34b.

[0032] A first return air duct 53 and a second return air duct 54, which are return air ducts for the cool air from the refrigerator compartment 11 and the freezer compartment 12, are provided in the lower region of the cooler compartment 3. As a result, the return air from the refrigerator compartment 11 and the freezer compartment 12 passes from the inlet 34a to the outlet 34b of the cooler 34, i.e., from the upstream end to the downstream end of the cooler 34 in the air flow direction D1. This maximizes the heat exchange distance between the return air from the refrigerator compartment 11 and the freezer compartment 12 and the cooler 34. As a result, the return air from the refrigerator compartment 11 and the freezer compartment 12 hits the entire volume of the cooler 34, enabling cooling using the entire cooler 34, and improving the heat exchange capacity between the cooler 34 and the refrigerant.

[0033] The cooler chamber 3 is also provided with a cooler chamber temperature sensor 36 that measures the cooler chamber temperature Te, which is the temperature of the air in the cooler chamber 3. The cooler chamber temperature sensor 36 is, for example, a thermistor. The cooler chamber temperature Te measured by the cooler chamber temperature sensor 36 is output to the control device 6.

[0034] 2 , the refrigerator 1 includes a defrost heater 41 provided in the cooler compartment 3, a drain pipe 42 and a drain heater 43 provided between the cooler compartment 3 and the machine compartment 30, and a drain pan 44 provided in the machine compartment 30. The defrost heater 41 is a heater that generates heat when energized, and melts frost adhering to the cooler 34.

[0035] The drain pipe 42 discharges meltwater produced by melting frost adhering to the cooler 34 into the drain pan 44. The drain heater 43 generates heat when energized and unfreezes the drain pipe 42. The drain heater 43 also melts the remaining ice that has fallen from the cooler 34 and guides it to the drain pipe 42 and then to the drain pan 44. The provision of the drain heater 43 prevents some of the meltwater from remaining in the cooler chamber 3 in the form of ice, which then solidifies and closes the drain pipe 42.

[0036] The melted frost water guided to the drain pan 44 is stored in the drain pan 44 and evaporates over a certain period of time in the machine room 30, which is heated to a high temperature by the heat generated by the compressor 31. The volume of the drain pan 44 is larger than the volume of the cooler 34, and is, for example, approximately 1.5 to 2.0 L. By making the volume of the drain pan 44 larger than the volume of the cooler 34, it is possible to prevent the water in the drain pan 44 from overflowing and spilling into the machine room 30.

[0037] The defrost heater 41 and the drain heater 43 are operated synchronously by the control device 6 during defrosting operation. Although the drain heater 43 is arranged adjacent to the drain pipe 42 in Fig. 2, the shape and arrangement of the drain heater 43 are not limited to the example in Fig. 2. For example, the drain heater 43 may be made of an aluminum foil heater or the like and wrapped around the drain pipe 42.

[0038] Inside the main body 2 of the refrigerator 1, a first air duct 51 for supplying the cold air generated by the cooler 34 to the refrigerator compartment 11 and a second air duct 52 for supplying the cold air to the freezer compartment 12 are provided. The arrows in Figures 2 and 3 indicate the flow of the cold air. In this embodiment, the blower 35 is controlled so that an appropriate amount of cold air is supplied to each of the first air duct 51 and the second air duct 52.

[0039] A damper 510 is provided in the first air duct 51. When the damper 510 is closed, the supply of cold air to the refrigerator compartment 11 is stopped. The amount of cold air supplied to the refrigerator compartment 11 is adjusted by adjusting the angle of the damper 510. The opening rate or angle of the damper 510 is controlled by the control device 6. Note that no damper is provided in the second air duct 52 connected to the freezer compartment 12.

[0040] A first return air duct 53 is provided between the bottom of the storage container 112 of the refrigerator compartment 11 and the bottom of the refrigerator compartment 11, and on the back side of the freezer compartment 12, for guiding the air that has passed through the refrigerator compartment 11 to the cooler compartment 3. A second return air duct 54 is provided between the bottom of the storage container 122 in the lower level of the freezer compartment 12 and the bottom of the freezer compartment 12, and on the back side of the freezer compartment 12, for guiding the air that has passed through the freezer compartment 12 to the cooler compartment 3.

[0041] 2 and 3 , the cold air cooled by the cooler 34 is sent by the blower 35 to the refrigerator compartment 11 and the freezer compartment 12. The cold air sent to the refrigerator compartment 11 passes through the damper 510 and the first air flow path 51, and is blown into the refrigerator compartment 11 from an air outlet provided on the back surface of the refrigerator compartment 11. The cold air sent to the freezer compartment 12 passes through the second air flow path 52, and is blown into the freezer compartment 12 from an air outlet provided on the back surface of the freezer compartment 12.

[0042] Part of the cold air blown into the refrigerator compartment 11 passes over the shelf 111 and flows downward at the front side of the refrigerator compartment 11. Part of the cold air blown into the refrigerator compartment 11 escapes from a gap in the upper part of the front wall of the storage container 112 into the space in front of the storage container 112. The cold air that escapes to the front space merges with the cold air that has flowed downward in the refrigerator compartment 11 and returns to the cooler compartment 3 through the first return air duct 53. The air blown into the freezer compartment 12 escapes from a gap in the upper part of the front wall of the storage container 122 into the space in front of the storage container 122, flows downward, and returns to the cooler compartment 3 through the second return air duct 54.

[0043] The refrigerator compartment 11 is provided with a refrigerator compartment temperature sensor 113 for measuring a refrigerator compartment temperature Tr, which is the temperature inside the refrigerator compartment 11. The freezer compartment 12 is provided with a freezer compartment temperature sensor 123 for measuring a freezer compartment temperature Tf, which is the temperature inside the freezer compartment 12. The refrigerator compartment temperature sensor 113 and the freezer compartment temperature sensor 123 are, for example, thermistors. The refrigerator compartment temperatures Tr and Tf measured by the refrigerator compartment temperature sensor 113 and the freezer compartment temperature sensor 123 are output to the control device 6. In the following description, either the refrigerator compartment temperature sensor 113 or the freezer compartment temperature sensor 123, or both, may be collectively referred to as the "compartment temperature sensor." Furthermore, either the refrigerator compartment temperature Tr or the freezer compartment temperature Tf, or both, may be collectively referred to as the "compartment temperature."

[0044] <Operation of Refrigerator 1> Next, a description will be given of the operation of the refrigerator 1. Fig. 6 is a control block diagram of the refrigerator 1 according to the first embodiment. As shown in Fig. 6, the control device 6 of the refrigerator 1 includes a storage unit 61, a cooling control unit 62, a heater control unit 63, an adjustment coefficient calculation unit 64, and a rank determination unit 65.

[0045] The memory unit 61 stores programs executed by the control device 6 and information used in the programs. For example, the memory unit 61 stores setting information input via the operation / display unit 18, parameters such as programs and thresholds used in the cooling operation and defrosting operation, and parameters such as programs and thresholds used for calculating adjustment coefficients and determining ranks, which will be described later. The memory unit 61 also stores the number of times the refrigerator compartment door 110 and the freezer compartment door 120 have been opened in the past, the opening times of the refrigerator compartment door 110 and the freezer compartment door 120, and the opening times of the refrigerator compartment door 110 and the freezer compartment door 120, together with date and time information. The memory unit 61 may be provided separately from the control device 6.

[0046] Cooling control unit 62 controls the temperature of each storage compartment based on the measurement results of each sensor in refrigerator 1, setting information input via operation and display unit 18, and the setting rank determined by rank determination unit 65. Specifically, cooling control unit 62 controls the rotation speed of compressor 31, the rotation speed of blower 35, and the angle of damper 510 so that the internal temperature measured by each internal temperature sensor becomes the preset temperature for each storage compartment.

[0047] The heater control unit 63 controls the energization state of the defrost heater 41 and the drain heater 43. Specifically, when performing a defrosting operation, the heater control unit 63 synchronously energizes the defrost heater 41 and the drain heater 43. The defrosting operation is performed when a defrosting condition is satisfied during normal cooling operation.

[0048] The adjustment coefficient calculation unit 64 calculates a first adjustment coefficient α Ｒ and α Ｆ , and the second adjustment coefficient β Ｒ and β Ｆ The first adjustment coefficient α Ｒ is a numerical value between 0 and 1 that indicates the rate at which a load (stored goods) is introduced into the refrigerator compartment 11 when the refrigerator compartment door 110 is opened or closed. The adjustment coefficient calculation unit 64 determines whether or not a load has been introduced at each opening or closing during a past preset calculation period based on the temperature rise value ΔTr and recovery time tr of the refrigerator compartment temperature Tr when the refrigerator compartment door 110 is opened or closed, and the temperature rise value ΔTe and recovery time te of the cooler compartment temperature Te, and calculates the first adjustment coefficient α Ｒ The first adjustment coefficient α Ｆ is a numerical value between 0 and 1 that indicates the rate at which a load (stored goods) is introduced into the freezer compartment 12 when the freezer compartment door 120 is opened or closed. The adjustment coefficient calculation unit 64 determines whether or not a load has been introduced at each opening or closing during a past preset calculation period based on the temperature rise value ΔTf of the freezer compartment temperature Tf and the recovery time tf when the freezer compartment door 120 is opened or closed, and the temperature rise value ΔTe of the cooler compartment temperature Te and the recovery time te, and calculates the first adjustment coefficient α Ｆ The first adjustment coefficient α Ｒ and α Ｆ The calculation method will be described in detail later.

[0049] At the beginning of use of the refrigerator 1, the adjustment coefficient calculation unit 64 calculates the first adjustment coefficient α Ｒ and α Ｆ The calculated result may be set to an initial value of 0.5. Then, as will be described later, the first adjustment coefficient α Ｒ and α Ｆ is calculated and reflected in the usage frequency rank. Note that the adjustment coefficient calculation unit 64 is not essential, and the first adjustment coefficient α Ｒ and α Ｆ may be set to 1.

[0050] Second adjustment coefficient β Ｒ and β Ｆ is a numerical value between 0 and 1 that represents the magnitude of the heat load that the storage compartment whose door has been opened / closed and the outside air temperature Ta impose on the cooler compartment 3. In order to improve the food preservation quality of the refrigerator 1, it is desirable to take into consideration the usage environment and usage conditions of the refrigerator 1. Therefore, when calculating the discrimination parameter X (described later) that determines the usage frequency rank, the first adjustment coefficient α Ｒ and α Ｆ , and the second adjustment coefficient β Ｒ and β Ｆ is used.

[0051] The adjustment coefficient calculation unit 64 calculates a second adjustment coefficient β based on the outside air temperature Ta measured by the outside air temperature sensor 19, the temperature inside the storage compartment with the door open (i.e., the refrigerator compartment temperature Tr or the freezer compartment temperature Tf), and the cooler compartment temperature Te. Ｒ and β Ｆ In detail, the adjustment coefficient calculation unit 64 calculates the second adjustment coefficient β using the following equations (1) and (2): Ｒ and β Ｆ Calculate β Ｒ =(Ta-Tr) / (32-Te)...(1) β Ｆ =(Ta-Tf) / (32-Te)...(2)

[0052] Second adjustment coefficient β Ｒ and β ＦThe physical meaning of this is that, based on the temperature of the cooler compartment 3 when the outside air temperature is 32°C, the temperature rise contribution level to the storage compartment when the door is opened is estimated according to each condition, and finally, the load on the refrigerant circuit of the refrigerator 1 is estimated. Ｒ and β Ｆ As shown in FIG. 7, the second adjustment coefficient β Ｒ and β Ｆ The higher the outdoor temperature, the larger the coefficient, and the lower the outdoor temperature, the smaller the coefficient. This is because the level of the heat penetration load from the outdoor air into the storage compartment is estimated and weighted. In addition, the second adjustment coefficient β Ｒ and β Ｆ The smaller the difference between the temperature of the storage compartment with the door open and the temperature of the cooler compartment 3, the larger the difference becomes, and the smaller the difference becomes. This is because, when the cooler compartment 3 is considered as the reference, if the difference between the temperatures of the cooler compartment 3 and the storage compartment is large, it is estimated that the contribution level to the temperature rise of the cooler compartment 3 is small and weighted accordingly. Here, the second adjustment coefficient β Ｒ and β Ｆ The reason why the reference outdoor temperature was set to 32°C in calculating the above is because the storage temperature test specified in the refrigerator specification standards (JIS9801-1 to 3:2015 or IEC62552-1 to 3:2015) is conducted at an outdoor temperature of 32°C.

[0053] The rank determination unit 65 determines the usage frequency rank of the refrigerator 1 for each time period. The time period is, for example, every hour starting from midnight. The rank determination unit 65 determines a discrimination parameter X ≡ ... Ｒ and X Ｆ The discrimination parameter X is calculated. Ｒ is the discrimination parameter of the refrigerator compartment 11, and the discrimination parameter X Ｆ is a discrimination parameter for the freezer compartment 12. Ｒ = α Ｒ ×β Ｒ ×N Ｒ ×T ＯＲ ... (3) X Ｆ = α Ｆ ×β Ｆ×N Ｆ ×T ＯＦ ...(4)

[0054] α in Equation (3) Ｒ and β Ｒ is the adjustment coefficient calculated by the adjustment coefficient calculation unit 64, and N Ｒ is the average value of the number of times the refrigerator door 110 is opened and closed during the same time period in a preset calculation period, and T ＯＲ is the average value of the opening time of the refrigerator door 110. Ｆ and β Ｆ is the adjustment coefficient calculated by the adjustment coefficient calculation unit 64, and N Ｆ is the average value of the number of times the freezer compartment door 120 is opened and closed during the same time period in a preset calculation period, and T ＯＦ is the average value of the open time of the freezer compartment door 120. The preset calculation period is, for example, the most recent week excluding the current day.

[0055] The rank determination unit 65 determines the discrimination parameter X Ｒ and X Ｆ The overall discrimination parameter X is calculated to determine the rank of the frequency of use of the refrigerator 1. The discrimination parameter X is calculated by the following equation (5): Ｒ and X Ｆ It is calculated by the sum of X = X Ｒ +X Ｆ ...(5)

[0056] The rank determination unit 65 compares the obtained discrimination parameter X with a preset threshold value to determine the usage frequency rank. As an example, the rank determination unit 65 classifies the usage frequency rank for each time period into five levels, FR1 to FR5, as shown below, according to the discrimination parameter X. Note that the threshold values ​​compared with the following discrimination parameter X are those when each adjustment coefficient is 0.5, and when each adjustment coefficient is 1, each threshold value is doubled. Specifically, the threshold value for usage frequency rank FR1 is "X≦20". 1) Usage frequency rank FR1: X≦10 2) Usage frequency rank FR2: 10<X≦50 3) Usage frequency rank FR3: 50<X≦100 4) Usage frequency rank FR4: 100<X≦150 5) Usage frequency rank FR5: 150<X

[0057] Use frequency rank FR1 is the least frequently used, and use frequency rank FR5 is the most frequently used. Use frequency rank FR1 corresponds to a time period when the device is not in use, use frequency ranks FR2 and FR3 correspond to time periods when the device is used less frequently, and use frequency ranks FR4 and FR5 correspond to time periods when the device is used more frequently. Note that the number of use frequency rank levels is not limited to five, and the levels can be classified into any number of levels equal to or greater than two.

[0058] The number of times the storage compartment door is opened and closed during each time period of the day varies from user to user, with frequent users opening and closing the door approximately 80 times per day. The length of time the storage compartment door is open during each opening and closing also varies from user to user, with some users closing the door within 30 seconds on average, while others leave it open for several minutes on average while searching for ingredients. The threshold value for the usage frequency rank FR1 (≦10) assumes that the number of openings and closings is less than 10 times and the opening time per opening is less than 1 minute, and this time period is considered a non-use time period.

[0059] Furthermore, the rank determination unit 65 determines a set rank for setting control parameters including at least one of the rotation speed of the compressor 31, the rotation speed of the blower 35, and the angle of the damper 510 during the first operation after defrosting (described later) based on the usage frequency rank and the outside air rank. The determination of the set rank will be described in detail later. The set rank determined by the rank determination unit 65 is transmitted to the cooling control unit 62.

[0060] Here, the hardware configuration of the control device 6 of the refrigerator 1 according to the present embodiment will be described. FIG. 8 is a diagram illustrating an example of the hardware configuration of the control device 6 of the refrigerator 1 according to the first embodiment. When the cooling control unit 62, the heater control unit 63, the adjustment coefficient calculation unit 64, and the rank determination unit 65 of the control device 6 are implemented in hardware, the control device 6 is configured with a processing circuit 600. The processing circuit 600 corresponds to, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof. The cooling control unit 62, the heater control unit 63, the adjustment coefficient calculation unit 64, and the rank determination unit 65 may each be implemented by separate processing circuits 600, or each unit may be implemented by a single processing circuit 600.

[0061] 9 is a diagram illustrating another example of the hardware configuration of the control device 6 of the refrigerator 1 according to the first embodiment. When the cooling control unit 62, the heater control unit 63, the adjustment coefficient calculation unit 64, and the rank determination unit 65 of the control device 6 are implemented by software, the control device 6 includes a processor 601 such as a CPU or a GPU, and a memory 602. The processor 601 and the memory 602 are connected to each other via a bus 603 so as to be able to communicate with each other. Note that the control device 6 may include a plurality of processors 601 and a plurality of memories 602, which cooperate to implement the cooling control unit 62, the heater control unit 63, the adjustment coefficient calculation unit 64, and the rank determination unit 65.

[0062] The cooling control unit 62, heater control unit 63, adjustment coefficient calculation unit 64, and rank determination unit 65 are realized by software, firmware, or a combination of software and firmware. The software and firmware are written as programs and stored in memory 602. The processor 601 realizes each unit by reading and executing the programs stored in memory 602. The memory 602 constitutes the storage unit 61 and is, for example, a non-volatile semiconductor memory such as a ROM or a flash memory, a volatile semiconductor memory such as a RAM, or a recording medium such as an HDD or SSD.

[0063] 10 is a diagram showing the operation and internal temperature of a conventional refrigerator. The conventional refrigerator has the same configuration as refrigerator 1 of the present embodiment, and performs a normal cooling operation, a defrosting operation for defrosting the cooler, and a cooling operation after the defrosting operation. In the description of the present disclosure, the normal cooling operation is referred to as a "normal operation," and the first cooling operation performed after the defrosting operation is referred to as a "first operation after defrosting."

[0064] In normal operation, as shown in Fig. 10, the freezer compartment temperature setting Tfs and the refrigerator compartment temperature setting Trs are set as target values, and the operation and stopping or angles of the compressor, the blower, and the damper are controlled so that the freezer compartment temperature Tf and the refrigerator compartment temperature Tr fall within the allowable ranges Tfs±dθf and Trs±dθr. The allowable ranges dθf and dθr vary depending on the insulation specifications of the refrigerator and the specifications of the cooler, but are, for example, 2 to 4 [K].

[0065] This controls the temperature and flow rate of the cold air blown into the refrigerator compartment and freezer compartment, maintaining the average value of the freezer compartment temperature Tf at the set temperature Tfs, and maintaining the average value of the refrigerator compartment temperature Tr at the set temperature Trs. That is, as shown in Figure 10, the operation or stop of the compressor and blower is synchronized with the freezer compartment temperature Tf, so that the freezer compartment is cooled while the compressor is operating, and cooling is temporarily stopped while the compressor is stopped, and the freezer compartment temperature Tf and the refrigerator compartment temperature Tr tend to rise.

[0066] When the defrosting conditions are met, the defrosting operation is started. In the defrosting operation, the compressor and the blower are stopped and the damper is closed. After that, the defrosting heater and the drain heater heat the cooler compartment, which also increases the temperatures inside the freezer and refrigerator compartments. When the defrosting operation ends, the cooling operation is restarted. In other words, the first operation after defrosting is performed.

[0067] In a conventional initial operation after defrosting, the compressor rotation speed and the blower rotation speed are set higher than those during normal operation. The damper angle is controlled to a preset constant angle. As described above, after defrosting operation, the temperatures inside the freezer compartment 12 and the refrigerator compartment 11 rise. If the temperatures in the freezer compartment 12 and the refrigerator compartment 11 remain high for a long period of time, there is a risk of stored items spoiling or thawing. Therefore, in the initial operation after defrosting, the compressor and the blower rotation speed are increased to quickly cool the freezer compartment 12 and the refrigerator compartment 11 and minimize the time during which the temperatures in the freezer compartment 12 and the refrigerator compartment 11 are high.

[0068] The problems of the conventional technology will now be described. Fig. 11 is a diagram illustrating the mechanism by which the freeze-drying phenomenon occurs in the conventional technology. As shown in Fig. 11, a storage item F1 such as food is stored in a storage chamber while being contained in a package P1. During normal operation, the temperature of the storage item F1 and the ambient temperature, which is the temperature of the air surrounding the storage item F1, are both low. When a defrosting operation is started, the ambient temperature rises, and the temperature of the storage item rises with a delay following the rise in the ambient temperature. Therefore, at the start of the defrosting operation, the ambient temperature is high and the temperature of the storage item is low.

[0069] At the end of the defrosting operation, both the ambient temperature and the temperature of the stored items are high. When the first post-defrosting operation is performed after the defrosting operation is completed, the ambient temperature drops rapidly, and the temperature of the stored items drops with a delay, following the drop in the ambient temperature. Therefore, at the start of the first post-defrosting operation, the ambient temperature is low and the temperature of the stored items is high. At this time, a water vapor pressure difference occurs within the package P1, causing moisture to evaporate from the stored items F1. This causes the stored items to dry out and deteriorate.

[0070] Therefore, in this embodiment, in the initial operation after defrosting, compressor 31, blower 35, and damper 510 are controlled so that there is no difference in temperature between the temperature of the stored items and the ambient temperature. Fig. 12 is a diagram showing the operation and internal temperature of refrigerator 1 according to embodiment 1. Refrigerator 1 of this embodiment performs normal operation, defrosting operation for defrosting cooler 34, and initial operation after defrosting, which is a cooling operation after the defrosting operation.

[0071] In normal operation, as in the prior art, the set temperature Tfs of the freezer compartment 12 and the set temperature Trs of the refrigerator compartment 11 are set as target values, and the operation and stopping or angles of the compressor 31, the blower 35, and the damper 510 are controlled so that the freezer compartment temperature Tf and the refrigerator compartment temperature Tr fall within the allowable ranges Tfs±dθf and Trs±dθr. The allowable range widths dθf and dθr vary depending on the insulation specifications of the refrigerator 1 and the specifications of the cooler 34, but are, for example, 2 to 4 [K].

[0072] When the defrosting conditions are met, the defrosting operation is started. In the defrosting operation, the compressor 31 and the blower 35 are stopped, and the damper is closed. Thereafter, the cooler compartment 3 is heated by the defrost heater 41 and the drain heater 43, thereby increasing the temperatures inside the freezer compartment 12 and the refrigerator compartment 11. When the defrosting operation is completed, the initial operation after defrosting is performed.

[0073] In the first operation after defrosting in this embodiment, the rotation speed of the compressor 31, the rotation speed of the blower 35, and the angle of the damper 510 are increased stepwise, thereby suppressing a sudden drop in the temperatures inside the refrigerator compartment 11 and the freezer compartment 12.

[0074] Fig. 13 is a flowchart showing the operation of the refrigerator 1 according to the first embodiment. The operation of Fig. 13 is started by the control device 6 at midnight every day and finished at midnight. First, the rank determination unit 65 of the control device 6 calculates the first adjustment coefficient α Ｒ and α Ｆ (S1) The first adjustment coefficient α Ｒ and α Ｆ The calculation method of the first adjustment coefficient α ＦThe first adjustment coefficient α in the refrigerator compartment 11 will be described as an example. Ｒ can be similarly obtained by replacing "freezer compartment 12" with "refrigerator compartment 11," "freezer compartment door 120" with "refrigerator compartment door 110," and "freezer compartment temperature Tf" with "refrigerator compartment temperature Tr" in the following description.

[0075] Fig. 14 is a diagram illustrating the change in freezing compartment temperature Tf when freezing compartment door 120 is opened and closed in embodiment 1. Fig. 14 shows the change in power [W] over time, the operation (ON) and stoppage (OFF) of compressor 31 and blower 35, and the change in freezing compartment temperature Tf measured by freezing compartment temperature sensor 123 over time.

[0076] In the cooling operation for cooling the freezer compartment 12, the cooling control unit 62 of the refrigerator 1 synchronizes the compressor 31 and the blower 35 and switches between operating and stopping so that the freezer compartment temperature Tf falls within the allowable range Tfs±dθf, with the set temperature Tfs of the freezer compartment 12 as a target value. The allowable range dθf varies depending on the insulation specifications of the refrigerator 1 and the specifications of the cooler 34, but is, for example, 2 to 4 [K].

[0077] This controls the temperature and flow rate of the cold air blown into the freezer compartment 12, and maintains the average value of the freezer compartment temperature Tf of the freezer compartment 12 at the set temperature Tfs. That is, the operation or stop of the compressor 31 and the blower 35 is synchronized with the freezer compartment temperature Tf of the freezer compartment 12, and the freezer compartment 12 is cooled while the compressor 31 is operating, and cooling is temporarily suspended while the compressor 31 is stopped, and the freezer compartment temperature Tf tends to rise.

[0078] The following describes changes in the freezer compartment temperature Tf when the freezer compartment door 120 is opened and closed during normal operation. In Fig. 14 , the solid line after the freezer compartment door 120 is opened indicates the temperature change in the freezer compartment temperature Tf when no load is applied to the freezer compartment 12 when the freezer compartment door 120 is opened and closed, and the dashed line indicates the temperature change in the freezer compartment temperature Tf when a load is applied to the freezer compartment 12 when the freezer compartment door 120 is opened and closed. When a load is applied to the freezer compartment 12 (the dashed line in Fig. 14 ), the rise in the freezer compartment temperature Tf is greater than when no load is applied to the freezer compartment 12 (the solid line in Fig. 14 ). Furthermore, when a load is applied to the freezer compartment 12, the recovery time tf_load required for the freezer compartment temperature Tf to return to the temperature immediately before the freezer compartment door 120 was opened is longer than the recovery time tf_unload required when no load is applied.

[0079] This is because the thermal load on the refrigerator 1 is greater when a new load is placed in the freezer compartment 12. When the door is opened and closed, the freezer compartment temperature Tf simply rises due to the cold air leaking from the freezer compartment 12 to the outside, but when a new load is placed in the freezer compartment 12, in addition to the temperature rise caused by the cold air leaking, it becomes necessary to additionally cool the load with a certain amount of heat. In other words, the additional thermal load of the load is placed on the refrigerator 1 (cooler 34), and it takes time to cool it down.

[0080] As described above, the temperature rise in the freezer compartment temperature Tf differs depending on whether or not a load is applied to the freezer compartment 12 when the freezer compartment door 120 of the refrigerator 1 is opened or closed, and the cooling capacity required for the refrigerator 1 also differs. The cooler compartment temperature Te also changes in the same way as the freezer compartment temperature Tf. That is, if a load is applied to the freezer compartment 12 when the freezer compartment door 120 is opened or closed, the temperature rise in the cooler compartment temperature Te is greater than when no load is applied to the freezer compartment 12. Furthermore, when a load is applied to the freezer compartment 12, the recovery time required for the cooler compartment temperature Te to return to the temperature immediately before the freezer compartment door 120 was opened is longer than the recovery time when no load is applied.

[0081] Therefore, the adjustment coefficient calculation unit 64 measures (1) the temperature rise values ​​of the freezer compartment temperature Tf and the cooler compartment temperature Te when the freezer compartment door 120 is opened or closed, and (2) the recovery times of the freezer compartment temperature Tf and the cooler compartment temperature Te. Then, the adjustment coefficient calculation unit 64 compares the temperature rise values ​​of the freezer compartment temperature Tf and the cooler compartment temperature Te with a threshold value (Tup1 in FIG. 14 ), and (2) compares the recovery time with a threshold time (tr in FIG. 14 ) to determine whether or not a load has been applied. The adjustment coefficient calculation unit 64 determines whether or not the load has been applied every time the freezer compartment door 120 is opened or closed during the calculation period, thereby calculating a first adjustment coefficient α Ｆ can be obtained.

[0082] Depending on the lifestyle of each user, there are significant differences in whether a load is frequently applied when the door is opened and closed, or whether the user only checks the inventory in the freezer compartment 12 without applying a load. Therefore, by estimating the rate at which a load is applied to the freezer compartment 12 and using this as a coefficient for the usage frequency rank, it is possible to estimate the usage frequency for each user, i.e., the magnitude of the heat load on the refrigerator 1. Then, by performing cooling control appropriate for the estimated heat load, it is possible to improve energy saving performance and user convenience.

[0083] FIG. 15 shows the first adjustment coefficient α Ｆ This process is performed by the adjustment coefficient calculation unit 64 of the control device 6. First, the adjustment coefficient calculation unit 64 resets a count C1 indicating the number of determinations that a load has been applied and a count C2 indicating the number of determinations that a load has not been applied (S101). That is, the count C1 indicating the number of determinations that a load has been applied and the count C2 indicating the number of determinations that a load has not been applied are set to 0.

[0084] Next, the adjustment coefficient calculation unit 64 determines whether the temperature rise value ΔTf of the freezer compartment temperature Tf when the freezer compartment door 120 is opened or closed is equal to or greater than the first threshold value Tup1, and whether the temperature rise value ΔTe of the cooler compartment temperature Te when the freezer compartment door 120 is opened or closed is equal to or greater than the second threshold value Tup2 (S102). The temperature rise value ΔTf of the freezer compartment temperature Tf and the temperature rise value ΔTe of the cooler compartment temperature Te when the freezer compartment door 120 is opened or closed are measured each time the freezer compartment door 120 is opened or closed, and are stored in the storage unit 61. The first threshold value Tup1 is, for example, 10 to 12 [K], and the second threshold value Tup2 is smaller than the first threshold value Tup1, for example, 8 to 10 [K]. The first threshold value Tup1 and the second threshold value Tup2 are merely examples, and are set appropriately depending on the insulation specifications of the refrigerator 1 and the specifications of the cooler 34.

[0085] Note that multiple first threshold values ​​Tup1 and second threshold values ​​Tup2 may be set for each outside air temperature Ta measured by the outside air temperature sensor 19. For example, when the outside air temperature Ta is high, the temperature rise value when the freezer compartment door 120 is opened will be larger than the temperature rise value when the freezer compartment door 120 is opened when the outside air temperature Ta is low. Therefore, by setting the first threshold value Tup1 and the second threshold value Tup2 according to the outside air temperature Ta, the accuracy of load application detection can be improved.

[0086] If at least one of the temperature increase value ΔTf of the freezer compartment temperature Tf and the temperature increase value ΔTe of the cooler compartment temperature Te is less than the threshold value (S102: NO), the adjustment coefficient calculation unit 64 determines that no load was applied during the opening / closing operation, and increments the no-load count C2 (S103). That is, if the temperature increase value ΔTf is less than the first threshold value Tup1 and the temperature increase value ΔTe is less than the second threshold value Tup2, if the temperature increase value ΔTf is equal to or greater than the first threshold value Tup1 but less than the second threshold value Tup2, or if the temperature increase value ΔTe is equal to or greater than the second threshold value Tup2 but less than the first threshold value Tup1, it is determined that no load was applied.

[0087] On the other hand, if the temperature rise value ΔTf of the freezer compartment temperature Tf is equal to or greater than the first threshold value Tup1 and the temperature rise value ΔTe of the cooler compartment temperature Te during the same opening and closing is equal to or greater than the second threshold value Tup2 (S102: YES), the adjustment coefficient calculation unit 64 determines whether the recovery time tf of the freezer compartment temperature Tf and the recovery time te of the cooler compartment temperature Te during the opening and closing of the freezer compartment door 120 are both equal to or greater than a predetermined threshold time th (S104). The threshold time th is, for example, 240 to 300 minutes. The threshold time th is an example and is set appropriately depending on the insulation specifications of the refrigerator 1 and the specifications of the cooler 34.

[0088] If at least one of the recovery time tf of the freezer compartment temperature Tf and the recovery time te of the cooler compartment temperature Te is shorter than the preset threshold time th (S104: NO), the adjustment coefficient calculation unit 64 determines that no load was applied at the time of opening or closing, and increments the no-load count C2 (S103). That is, if the recovery time tf is shorter than the threshold time th and the recovery time te is shorter than the threshold time th, if the recovery time tf is equal to or greater than the threshold time th but is shorter than the threshold time th, or if the recovery time te is equal to or greater than the threshold time th but is shorter than the threshold time th, it is determined that no load was applied.

[0089] On the other hand, if the recovery time tf of the freezer compartment temperature Tf and the recovery time te of the cooler compartment temperature Te are both equal to or greater than the threshold time th (S104: YES), the adjustment coefficient calculation unit 64 determines that a load was applied at the time of opening and closing, and counts up the load application count C1 (S105).

[0090] In step S104, the recovery time tf of the freezer compartment temperature Tf and the recovery time te of the cooler compartment temperature Te are compared with the threshold time th, but this is not limited to this. For example, the time tfu [min / K] required for the freezer compartment temperature Tf to drop by 1 [K] after the freezer compartment door 120 is closed and the time teu [min / K] required for the cooler compartment temperature Te to drop by 1 [K] may be compared with the reference time tru [min / K]. If both the time tfu and the time teu are equal to or greater than the time tru, the adjustment coefficient calculation unit 64 may determine that a load was applied during the opening and closing of the freezer compartment door 120 and increment the load application count C1. This allows the load application determination to be made regardless of the length of time the freezer compartment door 120 is open.

[0091] Then, the adjustment coefficient calculation unit 64 determines whether the sum of the counts C1 and C2 is equal to or greater than the total number N of times the freezer compartment door 120 has been opened and closed during the calculation period (the most recent week) (S106). If the sum of the counts C1 and C2 is less than the total number N (S106: NO), the process returns to step S102, and it is determined whether a load will be applied when the door is next opened or closed during the calculation period.

[0092] When the sum of the counts C1 and C2 is equal to or greater than the total number N (S106: YES), that is, when it has been determined whether or not a load has been applied when opening and closing all of the doors during the calculation period, the adjustment coefficient calculation unit 64 calculates the first adjustment coefficient α Ｆ is calculated (S107). Ｆ =C1 / (C1+C2)...(6)

[0093] As a result, the first adjustment coefficient α Ｆcan be calculated. In the above calculation method, both the freezer compartment temperature Tf and the cooler compartment temperature Te are used as criteria for determining whether a load is being applied, thereby improving the accuracy of estimating whether a load is being applied. Basically, the freezer compartment temperature Tf and the cooler compartment temperature Te in the refrigerator 1 change in an approximately linear proportional relationship with a certain temperature difference ΔT (Tf - Te). Therefore, if the temperature rise values ​​and recovery times of the freezer compartment temperature Tf and the cooler compartment temperature Te are synchronized, it is considered that the refrigerator 1 is operating normally. On the other hand, if the temperature rise values ​​and recovery times of the freezer compartment temperature Tf and the cooler compartment temperature Te are asynchronous, it is considered that some kind of abnormality or irregularity such as an external factor or a power outage has occurred. Therefore, if the temperature rise values ​​and recovery times of the freezer compartment temperature Tf and the cooler compartment temperature Te are asynchronous, it is determined that no load is being applied.

[0094] The determination based on the temperature rise value ΔTe of the cooler compartment temperature Te and the recovery time te is not essential and may be omitted. In this case, the temperature rise value ΔTf of the freezer compartment temperature Tf and the recovery time tf are only compared with the respective threshold values ​​to determine whether or not a load is applied.

[0095] Next, the first adjustment coefficient α Ｆ 16 is a flowchart showing a method for measuring the temperature rise value and recovery time when the door is opened and closed in the first embodiment. This process is performed by the adjustment coefficient calculation unit 64 of the control device 6. First, it is determined whether the freezer compartment door 120 has been opened (S111). If the freezer compartment door 120 has not been opened (S111: NO), the process waits until the door is opened.

[0096] If the freezer compartment door 120 is opened (S111: YES), the adjustment coefficient calculation unit 64 acquires the freezer compartment temperature Tf and the cooler compartment temperature Te as the initial freezer compartment temperature Tfo and the initial cooler compartment temperature Teo (S112). The initial freezer compartment temperature Tfo and the initial cooler compartment temperature Teo are the freezer compartment temperature Tf and the cooler compartment temperature Teo at the time when the opening of the freezer compartment door 120 is detected by the opening / closing sensor 17 and an opening signal is received, and are approximately the same as the freezer compartment temperature Tf and the cooler compartment temperature Te immediately before the freezer compartment door 120 is opened. Then, measurement of the temperature rise time tup of the freezer compartment temperature Tf and the cooler compartment temperature Te is started (S113).

[0097] Next, it is determined whether the freezer compartment door 120 is closed (S114). If the freezer compartment door 120 is not closed (S114: NO), the process waits until the freezer compartment door 120 is closed. Then, when the freezer compartment door 120 is closed (S114: YES), the adjustment coefficient calculation unit 64 acquires the freezer compartment temperature Tf1 and the cooler compartment temperature Te1 at time t1 (S115).

[0098] The adjustment coefficient calculation unit 64 waits for a time Δt1 (S116), and acquires the freezer compartment temperature Tf2 and the cooler compartment temperature Te2 at time t+Δt1 (S117). Then, the adjustment coefficient calculation unit 64 calculates the temperature gradient Sf of the freezer compartment temperature Tf and the temperature gradient Se of the cooler compartment temperature Te from the following equations (7) and (8) (S118). Sf=(Tf2-Tf1) / Δt1 (7) Se=(Te2-Te1) / Δt1 (8)

[0099] The adjustment coefficient calculation unit 64 then simultaneously checks the temperature rise changes in the freezer compartment temperature Tf and the cooler compartment temperature Te. First, the freezer compartment temperature Tf will be described. The adjustment coefficient calculation unit 64 determines whether the temperature gradient Sf of the freezer compartment temperature Tf is greater than 0 and whether the freezer compartment door 120 is closed (S119). If the temperature gradient Sf of the freezer compartment temperature Tf is greater than 0 and the freezer compartment door 120 is closed (S119: YES), it determines that the rise in the freezer compartment temperature Tf has not yet finished and that the upward trend is continuing, and the process returns to step S115, where the processes of steps S115 to S118 are repeated to calculate the most recent temperature gradient Sf.

[0100] On the other hand, if the temperature gradient Sf of the freezer compartment temperature Tf is equal to or less than 0, or if the freezer compartment door 120 is opened again (S119: NO), it is determined that the rise in the freezer compartment temperature Tf has reached its peak value, and the freezer compartment temperature Tf at this time is acquired as the peak freezer compartment temperature Tfmax (S120).Then, the initial freezer compartment temperature Tfo acquired in step S112 is subtracted from the peak freezer compartment temperature Tfmax acquired in step S120 to calculate a temperature rise value ΔTf of the freezer compartment temperature Tf (S121).

[0101] Next, the cooler compartment temperature Te will be described. The adjustment coefficient calculation unit 64 determines whether the temperature gradient Se of the cooler compartment temperature Te is greater than 0 and whether the freezer compartment door 120 is closed (S122). If the temperature gradient Sf of the cooler compartment temperature Te is greater than 0 and the freezer compartment door 120 is closed (S122: YES), it is determined that the cooler compartment temperature Te has not yet finished rising and continues to rise, and the process returns to step S115, where the processes of steps S115 to S118 are repeated to calculate the most recent temperature gradient Se.

[0102] On the other hand, if the temperature gradient Se of the cooler compartment temperature Te is equal to or less than 0, or if the freezer compartment door 120 is opened again (S122: NO), it is determined that the rise in the cooler compartment temperature Te has reached its peak value, and the cooler compartment temperature Te at this time is acquired as the peak cooler compartment temperature Temax (S123).Then, the initial cooler compartment temperature Teo acquired in step S112 is subtracted from the peak cooler compartment temperature Temax acquired in step S123 to calculate the temperature rise value ΔTe of the cooler compartment temperature Te (S124).

[0103] This makes it possible to determine the temperature rise value ΔTf of the freezer compartment temperature Tf and the temperature rise value ΔTe of the cooler compartment temperature Te each time the freezer compartment door 120 is opened or closed. The determined temperature rise value ΔTf of the freezer compartment temperature Tf and the temperature rise value ΔTe of the cooler compartment temperature Te are stored in the memory unit 61 together with the date and time.

[0104] Next, a method for measuring the recovery time when the door is opened and closed will be described. FIG. 17 is a flowchart showing a method for measuring the recovery time when the door is opened and closed in the first embodiment. This process is performed by the adjustment coefficient calculation unit 64 of the control device 6 in parallel with the calculation of the temperature rise value. First, it is determined whether or not the freezer compartment door 120 has been opened (S131). If the freezer compartment door 120 has not been opened (S131: NO), the process waits until the freezer compartment door 120 is opened. If the freezer compartment door 120 has been opened (S131: YES), it is determined whether or not the freezer compartment door 120 has been closed (S132). If the freezer compartment door 120 has not been closed (S132: NO), the process waits until the freezer compartment door 120 is closed.

[0105] If the freezer compartment door 120 is closed (S132: YES), the adjustment coefficient calculation unit 64 starts measuring the recovery times tf and te (S133). After that, the adjustment coefficient calculation unit 64 waits for a time Δt2 (S134) and acquires the freezer compartment temperature Tf and the cooler compartment temperature Te (S135). Then, it is confirmed whether the freezer compartment temperature Tf and the cooler compartment temperature Te have returned to the initial freezer compartment temperature Tfo and the initial cooler compartment temperature Teo, respectively.

[0106] First, the freezer compartment temperature Tf will be described. The adjustment coefficient calculation unit 64 determines whether the freezer compartment temperature Tf is equal to or lower than the initial freezer compartment temperature Tfo (S136). If the freezer compartment temperature Tf is higher than the initial freezer compartment temperature Tfo (S136: NO), the process returns to step S134, where the freezer compartment temperature Tf is acquired every time Δt2, and the adjustment coefficient calculation unit 64 determines whether the freezer compartment temperature Tf has returned to the initial freezer compartment temperature Tfo. If the freezer compartment temperature Tf is equal to or lower than the initial freezer compartment temperature Tfo (S136: YES), the adjustment coefficient calculation unit 64 determines that the freezer compartment temperature Tf has returned to the temperature before the freezer compartment door 120 was opened, and acquires the time at which this occurred as the recovery time tf (S137).

[0107] Next, the cooler compartment temperature Te will be described. The adjustment coefficient calculation unit 64 determines whether the cooler compartment temperature Te is equal to or lower than the initial cooler compartment temperature Teo (S138). If the cooler compartment temperature Te is higher than the initial cooler compartment temperature Teo (S138: NO), the process returns to step S134, where the cooler compartment temperature Te is acquired every time Δt2, and a determination is made as to whether the cooler compartment temperature Teo has returned to the initial cooler compartment temperature Teo. If the cooler compartment temperature Te becomes equal to or lower than the initial cooler compartment temperature Teo (S138: YES), the adjustment coefficient calculation unit 64 determines that the cooler compartment temperature Te has returned to the initial cooler compartment temperature Teo, and acquires the time at which this occurs as the return time te (S139).

[0108] This makes it possible to determine the recovery time tf of the freezer compartment temperature Tf and the recovery time te of the cooler compartment temperature Te each time the freezer compartment door 120 is opened or closed. The determined recovery time tf of the freezer compartment temperature Tf and the recovery time te of the cooler compartment temperature Te are stored in the memory unit 61 together with the date and time.

[0109] Returning to FIG. 13, the adjustment factor calculation unit 64 calculates the second adjustment factor β Ｒ and β Ｆ (S2). Then, the rank determining unit 65 determines the usage frequency rank for each time slot of the day (S3). The usage frequency rank is determined by the discrimination parameter X Ｒ and X Ｆ The parameter is determined based on the discriminant parameter X calculated from

[0110] Next, the cooling control unit 62 determines whether the defrosting conditions are satisfied (S4). The defrosting conditions include the cumulative operating time of the compressor 31 of the refrigerator 1 being equal to or longer than a specified time, the number of times the storage compartment door is opened and closed or the open time being equal to or longer than a specified amount, or the level of fluctuation in the first or third internal temperature being detected and a determination that the cooling capacity is insufficient.

[0111] If the defrosting conditions are not satisfied (S4: NO), the cooling control unit 62 performs normal operation (S5). If the defrosting conditions are satisfied (S4: YES), the cooling control unit 62 performs defrosting operation (S6). In the defrosting operation, the cooling control unit 62 first stops the compressor 31 and the blower 35 and closes the damper 510. Thereafter, the heater control unit 63 energizes the defrost heater 41 and the drain heater 43 to start heating. This heats the cooler 34 and defrosts it.

[0112] Next, the cooling control unit 62 determines whether a termination condition for the defrosting operation has been satisfied (S7). The termination condition for the defrosting operation is, for example, that a preset defrosting time (e.g., 3 minutes) has elapsed since the start of the defrosting operation. If the termination condition for the defrosting operation has not been satisfied (S7: NO), the defrosting operation continues. If the termination condition for the defrosting operation has been satisfied (S7: YES), the heater control unit 63 stops the defrost heater 41 and the drain heater 43 and terminates the defrosting operation (S8).

[0113] After the defrosting operation is completed, the cooling control unit 62 performs the initial post-defrosting operation (S9). FIG. 18 is a flowchart showing the flow of the initial post-defrosting operation in the first embodiment. The following describes an example in which priority is given to suppressing evaporation of moisture from the stored items in the freezer compartment 12. First, the rank determination unit 65 determines the outdoor air rank for the current time slot based on the outdoor air temperature Ta measured by the outdoor air temperature sensor 19 (S91). As an example, the outdoor air rank for each time slot is classified into six levels AR1 to AR6 according to the outdoor air temperature Ta, as follows: 1) outdoor air rank AR1: Ta<12°C 2) outdoor air rank AR2: 12°C≦Ta<18°C 3) outdoor air rank AR3: 18°C≦Ta<22°C 4) outdoor air rank AR4: 22°C≦Ta<28°C 5) outdoor air rank AR5: 28°C≦Ta<36°C 6) outdoor air rank AR6: 36°C≦Ta

[0114] Furthermore, the rank determination unit 65 determines an initial set rank based on the usage frequency rank for the current time period and the outdoor air rank (S92). The initial set rank is the set rank when the compressor 31 and the blower 35 are started during the first operation after defrosting. FIG. 19 is an example of a table showing set ranks according to the usage frequency rank and the outdoor air rank during the first operation after defrosting in Embodiment 1. The table of FIG. 16 is stored in the storage unit 61 of the refrigerator 1. As shown in FIG. 19, ten set ranks, from SR1 to SR10, are determined according to the usage frequency rank and the outdoor air rank. The rank determination unit 65 determines an initial set rank according to the usage frequency rank and the outdoor air rank using the table.

[0115] Basically, the higher the outdoor air rank, the greater the external heat load is determined to be, and the higher the set rank is set. Similarly, the higher the usage frequency rank, the greater the input heat load is determined to be, and the higher the set rank is set. This allows the refrigeration capacity to be increased when the outdoor air rank and usage frequency rank are high.

[0116] In Fig. 19, the set ranks are set to 10 levels, but the rank classification is not limited to this. For example, the set ranks may be classified more finely, such as 1 to 30 levels. Furthermore, the use frequency ranks and outdoor air ranks are not limited to the example in Fig. 19, and may be classified more finely, such as 1 to 30 levels, or more roughly, such as 1 to 3 levels. Regarding the rank classification, the finer the levels, the more memory space is required, so it is recommended to classify the ranks according to the memory space to be used.

[0117] Returning to Figure 18, when the initial setting rank is determined by the rank determination unit 65, the cooling control unit 62 sets the rotation speed of the compressor 31, the rotation speed of the blower 35, and the angle of the damper 510 based on the determined set rank, and starts the compressor 31 and the blower 35 (S93).

[0118] FIG. 20 is an example of a map of control parameters for each setting rank during the first operation after defrosting in the first embodiment. As shown in FIG. 20 , the rotation speeds of the compressor 31 and the blower 35 among the control parameters are set to minimum values ​​for the lowest setting rank SR1 and maximum values ​​for the highest setting rank SR10, with equal intervals between each setting rank. Furthermore, the angle θ of the damper 510 is set to 0 degrees (fully closed) for the lowest setting rank SR1 and 90 degrees (fully open) for the highest setting rank SR10, with equal intervals between each setting rank. The map of FIG. 20 is set in advance and stored in the storage unit 61.

[0119] The map of control parameters for each setting rank during the first operation after defrosting is not limited to the example in Fig. 20 , and a target refrigeration capacity for each outdoor air rank and each usage frequency rank may be determined in advance by experiment or the like, and a value for each rank may be set according to the target refrigeration capacity. This allows settings appropriate for each refrigerator type.

[0120] FIG. 21 is a diagram illustrating the angle θ of the damper 510 in the first embodiment. The arrow in FIG. 21 indicates the flow direction of the cooling air. The damper 510 is attached to the first air passage 51 so as to be rotatable about an axis 511. As shown in FIG. 21 , the state in which the damper 510 extends parallel to the horizontal direction and closes the first air passage 51 is defined as 0 degrees (fully closed), and the state in which the damper 510 extends parallel to the vertical direction and opens the first air passage 51 is defined as 90 degrees (fully open). In other words, the higher the set rank, the greater the opening degree of the damper 510.

[0121] Next, the rank determination unit 65 determines whether the elapsed time t since the start of operation at the currently set rank is equal to or greater than a preset rank-up time trup (S94). The rank-up time trup is preset and stored in the memory unit. If the elapsed time t is less than the rank-up time trup (S94: NO), the process proceeds to step S96. On the other hand, if the elapsed time t is equal to or greater than the rank-up time trup (S94: YES), the rank determination unit 65 increases the currently set rank by one (S95). For example, if the currently set rank is SR1, after the rank-up time trup has elapsed, the set rank is changed to SR2, and the rotation speeds of the compressor 31 and the blower 35 and the angle of the damper 510 are increased to match the new set rank.

[0122] The cooling control unit 62 then determines whether the freezer compartment temperature Tf is equal to or lower than the lower limit (Tfs-dθf) of the allowable range of the set temperature Tfs (S96). If the freezer compartment temperature Tf is greater than the lower limit (Tfs-dθf) of the allowable range of the set temperature Tfs (S96: NO), the process returns to step S94 and the subsequent steps are repeated. As a result, the set rank is increased each time the rank-up time trup elapses, and the rotation speeds of the compressor 31 and the blower 35 and the angle of the damper 510 are increased stepwise. If the set rank reaches the highest rank while the freezer compartment temperature Tf is greater than the lower limit (Tfs-dθf) of the allowable range of the set temperature Tfs and further increase in rank is not possible, operation at the highest set rank continues.

[0123] When the freezer compartment temperature Tf becomes equal to or lower than the lower limit (Tfs-dθf) of the allowable range of the set temperature Tfs (S96: YES), the initial operation after defrosting ends and the operation shifts to normal operation.

[0124] Fig. 22 is a diagram showing the relationship between the temperature of stored items in the freezer compartment and the ambient temperature before and after a defrosting operation in the prior art, and Fig. 23 is a diagram showing the relationship between the temperature of stored items in the freezer compartment and the ambient temperature before and after a defrosting operation in embodiment 1. In Fig. 22 and Fig. 23, the stored item temperature Tm is shown by a dashed line, and the ambient temperature is shown by a solid line. The ambient temperature is the freezer compartment temperature Tf.

[0125] As shown in Figure 22, during normal operation, the compressor is repeatedly turned on and off, causing the freezer compartment temperature Tf to fluctuate around a certain reference value. Because air has a small heat capacity, its temperature changes quickly, but stored items have a heat capacity greater than a certain level, so their temperature changes more slowly than air. This time difference in temperature change can cause the freezer compartment temperature Tf to be lower than the stored item temperature Tm, resulting in the freeze-drying phenomenon described above.

[0126] This temperature change due to the time difference occurs more significantly during the initial post-defrost operation after the defrost operation has ended. In the prior art, as described above, during the initial post-defrost operation, the compressor and the blower are operated at a higher rotation speed than in normal operation in order to quickly cool the temperature inside the storage compartment that rose during the defrost operation. In this case, a temperature difference between the stored item temperature Tm and the freezer compartment temperature Tf is more likely to occur, resulting in more rapid evaporation of moisture from the stored items compared to normal operation. That is, the larger the region R0 where the freezer compartment temperature Tf is lower than the stored item temperature Tm, as shown by the hatching in Figure 22, the more moisture evaporates from the stored items.

[0127] In contrast, in the present embodiment, as shown in FIG. 23 , the compressor 31, the blower 35, and the damper 510 are controlled so that there is no difference between the stored item temperature Tm and the freezer compartment temperature Tf during the initial post-defrost operation. As a result, the temperature change during normal operation is the same as in the prior art, but the control parameters are gradually increased during the initial post-defrost operation, so that the freezer compartment 12 is cooled more slowly than under normal conditions. This control to slowly cool the freezer compartment 12 reduces the difference between the temperature change in the freezer compartment temperature Tf and the temperature change in the food, thereby reducing the region R1, shown by the hatching in FIG. 23 , where the freezer compartment temperature Tf is lower than the stored item temperature Tm, compared to the prior art. As a result, moisture evaporation from the stored items is reduced more than in the prior art. Similarly, in the refrigerator compartment 11, the initial post-defrost operation of the present embodiment cools the freezer compartment 12 more slowly than under normal conditions, reducing the region where the refrigerator compartment temperature Tr is lower than the stored item temperature Tm, as in FIG. 23 .

[0128] In addition, in the refrigerator 1 of this embodiment, the initial values ​​of the control parameters when starting the first operation after defrosting are set according to the outside air temperature Ta and the frequency of use. This allows the rotation speeds of the compressor 31 and the blower 35 and the angle of the damper 510 to be set appropriate for each frequency of use, thereby enabling operation appropriate for the expected thermal load. Furthermore, during times when the refrigerator 1 is used less frequently and the load on the cooler compartment 3 is low, the compressor 31 and the blower 35 are not operated at rotation speeds higher than necessary, preventing the blowing of more cooling air than necessary to each storage compartment and reducing the difference in temperature change between the stored item temperature Tm and the ambient temperature. This prevents moisture evaporation from the stored items and prevents deterioration of the stored items.

[0129] In the above embodiment, the first adjustment coefficient α Ｒ , α Ｆ , and the second adjustment coefficient β Ｒ , β Ｆ Using both the discriminant parameter X Ｒ , X Ｆ was calculated, but the first adjustment coefficient α Ｒ , α Ｆ , or the second adjustment coefficient β Ｒ , β Ｆ The discrimination parameter X is obtained by using only one of the above. Ｒ , X Ｆ Alternatively, the first adjustment coefficient α Ｒ , α Ｆ , and the second adjustment coefficient β Ｒ , β Ｆ The discrimination parameter X is calculated by multiplying the average number of times the door of the storage room is opened and closed in the same time period during a predetermined calculation period by the average time the door of the storage room is open. Ｒ , X Ｆ may be calculated.

[0130] Embodiment 2. Embodiment 2 will be described. The refrigerator 1 of embodiment 2 differs from embodiment 1 in the method of determining the setting rank of the control parameters during the first operation after defrosting. The configuration of the refrigerator 1 in embodiment 2 is the same as that of embodiment 1, and the following description will focus on the differences. Also in embodiment 2, a case where priority is given to suppressing evaporation of moisture from stored items in freezer compartment 12 will be described as an example.

[0131] In the first embodiment, the rank determination unit 65 determined the set rank according to the usage frequency rank and the outdoor air rank during the first operation after defrosting. In contrast, the rank determination unit 65 in the present embodiment determines the set rank according to the maximum temperature Tfdmax of the freezer compartment temperature Tf during defrosting operation and the outdoor air rank. The maximum temperature Tfdmax is the highest temperature among the freezer compartment temperatures Tf measured by the freezer compartment temperature sensor 123 from the start to the end of the defrosting operation.

[0132] Fig. 24 is a flowchart showing the operation of the refrigerator 1 according to the second embodiment. The operation of Fig. 24 is started by the control device 6 at midnight every day and finished at midnight. In this embodiment, the first adjustment coefficient α Ｒ , α Ｆ , and the second adjustment coefficient β Ｒ , β Ｆ Calculation of the coefficient of the first refrigerator 1 and determination of the usage frequency rank are not performed. Therefore, in the refrigerator 1 of this embodiment, the adjustment coefficient calculation unit 64 of the control device 6 can be omitted. The cooling control unit 62 determines whether the defrosting conditions are satisfied (S201). The defrosting conditions include the cumulative operating time of the compressor 31 of the refrigerator 1 being equal to or greater than a specified time, the number of times the storage compartment door is opened or closed or the open time being equal to or greater than a specified amount, or the fluctuation level of the first compartment temperature or the third compartment temperature being detected and a determination that the cooling capacity is insufficient.

[0133] If the defrosting conditions are not satisfied (S201: NO), the cooling control unit 62 performs normal operation (S202). If the defrosting conditions are satisfied (S201: YES), the cooling control unit 62 performs defrosting operation (S203). In the defrosting operation, the cooling control unit 62 first stops the compressor 31 and the blower 35 and closes the damper 510. Thereafter, the heater control unit 63 energizes the defrost heater 41 and the drain heater 43 to start heating. This heats the cooler 34, and defrosting is performed.

[0134] Next, the cooling control unit 62 determines whether a termination condition for the defrosting operation has been satisfied (S204). The termination condition for the defrosting operation is, for example, that a preset defrosting time (e.g., 3 minutes) has elapsed since the start of the defrosting operation. If the termination condition for the defrosting operation has not been satisfied (S204: NO), the defrosting operation continues. If the termination condition for the defrosting operation has been satisfied (S204: YES), the heater control unit 63 stops the defrost heater 41 and the drain heater 43 and terminates the defrosting operation (S205).

[0135] After the defrosting operation is completed, the rank determination unit 65 determines a temperature rise rank based on the maximum temperature Tfdmax of the freezer compartment temperature Tf during the defrosting operation (S206). As an example, the temperature rise rank for each defrosting operation is classified into five levels TR1 to TR5 according to the maximum temperature Tfdmax during the defrosting operation as follows: 1) Temperature rise rank TR1: Tfdmax≦−18°C 2) Temperature rise rank TR2: −18°C<Tfdmax≦−12°C 3) Temperature rise rank TR3: −12°C<Tfdmax≦−6°C 4) Temperature rise rank TR4: −6°C<Tfdmax<0°C 5) Temperature rise rank TR5: 0°C≦Tfdmax

[0136] Then, the cooling control unit 62 performs the initial operation after defrosting (S207). The flow of the initial operation after defrosting is the same as that of the first embodiment shown in Fig. 18. However, in this embodiment, in step S92, the rank determination unit 65 determines an initial setting rank based on the temperature rise rank determined in step S206 and the outside air rank.

[0137] Fig. 25 is an example of a table showing set ranks corresponding to temperature rise ranks and outdoor air ranks during defrosting operation in Embodiment 2. The table of Fig. 25 is stored in the storage unit 61 of the refrigerator 1. As shown in Fig. 25, ten set ranks, from SR1 to SR10, are determined according to the temperature rise rank and the outdoor air rank. The rank determination unit 65 uses the table to determine an initial set rank corresponding to the temperature rise rank and the outdoor air rank.

[0138] Basically, the higher the outdoor air rank, the greater the external heat load is determined to be, and the higher the set rank is set. Similarly, the higher the temperature rise rank, the greater the input heat load is determined to be, and the higher the set rank is set. This allows the refrigeration capacity to be increased when the outdoor air rank and temperature rise rank are high.

[0139] In Fig. 25, the set ranks are set into 10 levels, but the rank classification is not limited to this. For example, the set ranks may be classified more finely, such as into levels 1 to 30. Furthermore, the temperature rise ranks and outdoor air ranks are not limited to the example in Fig. 25, and may be classified more finely, such as into levels 1 to 30, or more roughly, such as into levels 1 to 3. Regarding the rank classification, the finer the levels, the more memory area is required, so it is recommended to classify the ranks according to the memory area to be used.

[0140] In this manner, in this embodiment as well, the storage compartment is prevented from being cooled suddenly during the first operation after defrosting, and the difference in fluctuation between the stored item temperature Tm and the ambient temperature can be reduced. This reduces evaporation of moisture from the stored items and prevents deterioration of the stored items. Furthermore, by determining the setting rank using the maximum temperature Tfdmax of the freezer compartment temperature Tf during defrosting operation, it is possible to determine whether the stored items in the freezer compartment 12 are in a state where they are likely to melt. This allows the compressor 31, the blower 35, and the damper 510 to be operated at appropriate setting values ​​depending on whether rapid cooling is required or whether slow cooling is required to prevent evaporation of moisture from the stored items.

[0141] Embodiment 3. Embodiment 3 will be described. Refrigerator 1A of embodiment 3 differs from embodiment 1 in that it includes a stored item temperature sensor 135 and performs temperature control using stored item temperature Tm measured by stored item temperature sensor 135. Other configurations of refrigerator 1A in embodiment 3 are the same as those in embodiment 1, and the following description will focus on the differences. Also in embodiment 3, a case where priority is given to suppressing evaporation of moisture from stored items in freezer compartment 12 will be described as an example.

[0142] Fig. 26 is a cross-sectional view of a refrigerator according to embodiment 3. Fig. 26 is a cross-sectional view that corresponds to the cross-sectional view of embodiment 1 shown in Fig. 2. Refrigerator 1A according to this embodiment has the same configuration as refrigerator 1 according to embodiment 1, and further includes a stored item temperature sensor 135 in freezer compartment 12 that measures stored item temperature Tm, which is the temperature of the stored item in freezer compartment 12. Stored item temperature sensor 135 is, for example, an infrared sensor.

[0143] 26, in order to measure the temperatures of stored items in the multiple storage containers 122 in the freezer compartment 12, stored item temperature sensors 135 are provided on the ceiling of the freezer compartment 12 and on the bottom of the upper storage container 122. By using the stored item temperature sensors 135, the temperatures of the stored items stored in the freezer compartment 12 can be measured more accurately than in the first embodiment, and it can be determined more accurately whether the stored item temperature Tm is too low compared to the ambient temperature during the first operation after defrosting.

[0144] FIG. 27 is a flowchart showing the flow of the initial post-defrost operation in the third embodiment. The processing in steps S301 to S305 in the initial post-defrost operation in this embodiment is the same as steps S91 to S95 in the initial post-defrost operation in the first embodiment shown in FIG. 18. If the elapsed time t since the start of operation at the current set rank is less than the preset rank-up time trup (S304: NO), or after the current set rank is increased by one rank (S305), the freezer compartment temperature Tf11 and the stored item temperature Tm11 at time t11 are measured (S306). Here, the average value of the stored item temperatures Tm measured by the multiple stored item temperature sensors 135 is set as the stored item temperature Tm11.

[0145] Thereafter, the system waits for a time Δt11 (S307), and the freezer compartment temperature Tf12 and the stored item temperature Tm12 at the time t11+Δt11 are measured (S308). Here, the average value of the stored item temperatures Tm measured by the multiple stored item temperature sensors 135 is set as the stored item temperature Tm12. Then, the rank determination unit 65 calculates the temperature gradient Sfd of the freezer compartment temperature Tf and the temperature gradient Smd of the stored item temperature Tm using the following equations (9) and (10) (S309). Sfd=(Tf12-Tf11) / Δt11 (9) Smd=(Tm12-Tm11) / Δt11 (10)

[0146] Next, the rank determination unit 65 determines whether the temperature gradient Sfd of the freezer compartment temperature Tf is smaller than the temperature gradient Smd of the stored item temperature Tm (S310). If the temperature gradient Sfd of the freezer compartment temperature Tf is equal to or greater than the temperature gradient Smd of the stored item temperature Tm (S310: NO), that is, if the negative gradient of the freezer compartment temperature Tf is equal to or smaller than the negative gradient of the stored item temperature Tm, the process proceeds to step S312.

[0147] On the other hand, if the temperature gradient Sfd of the freezer compartment temperature Tf is smaller than the temperature gradient Smd of the stored item temperature Tm (S310: YES), i.e., if the freezer compartment temperature Tf has a more negative gradient than the stored item temperature Tm, the rank determination unit 65 lowers the set rank by one rank (S311). For example, if the current set rank is SR3, the set rank is changed to SR2, and the rotation speeds of the compressor 31 and the blower 35 and the angle of the damper 510 are lowered to match the new set rank. In this case, it is determined that the temperature change of the ambient air in the freezer compartment 12 is greater than the temperature change of the stored item temperature Tm, and lowering the set rank can weaken the cooling of the storage compartment.

[0148] The cooling control unit 62 then determines whether the freezer compartment temperature Tf is equal to or lower than the lower limit (Tfs-dθf) of the allowable range of the set temperature Tfs (S312). If the freezer compartment temperature Tf is greater than the lower limit (Tfs-dθf) of the allowable range of the set temperature Tfs (S312: NO), the process returns to step S304 and the subsequent steps are repeated. As a result, the set rank is increased each time the rank-up time trup elapses, and the rotation speeds of the compressor 31 and the blower 35 and the angle of the damper 510 are increased stepwise. Furthermore, if the temperature change of the ambient air in the freezer compartment 12 is greater than the temperature change of the stored item temperature Tm, the set rank is decreased, and the rotation speeds of the compressor 31 and the blower 35 and the angle of the damper 510 are decreased stepwise. Here, if the freezer temperature Tf is greater than the lower limit value (Tfs-dθf) of the allowable range of the set temperature Tfs and the set rank reaches the lowest rank, and it is not possible to lower the rank any further, operation will continue at the lowest set rank.

[0149] When the freezer compartment temperature Tf becomes equal to or lower than the lower limit (Tfs-dθf) of the allowable range of the set temperature Tfs (S312: YES), the initial operation after defrosting ends and the operation shifts to normal operation.

[0150] As described above, in this embodiment, too, it is possible to prevent the storage compartment from being suddenly cooled during the first operation after defrosting and to reduce the difference in fluctuation between the stored item temperature Tm and the ambient temperature. This makes it possible to suppress evaporation of moisture from the stored items and to prevent deterioration of the stored items. Furthermore, by adjusting the setting rank using the stored item temperature Tm measured by the stored item temperature sensor 135, it is possible to more accurately control the compressor 31 and other components according to the conditions in the storage compartment, and more efficiently suppress evaporation of moisture from the stored items.

[0151] The above is a description of the embodiment, but the present disclosure is not limited to the following embodiment and can be modified in various ways without departing from the spirit and scope of the present disclosure. Furthermore, the present disclosure includes all possible combinations of the configurations shown in the following embodiment and its modifications. For example, in the above embodiment, refrigerator 1 was described as an example of a storage compartment, but the present disclosure can also be applied to a freezer or refrigerator that cools stored items to a single temperature range. In this case, thresholds for ranking and discrimination are appropriately set according to the temperature range of the storage compartment. Furthermore, when the present disclosure is applied to a freezer, damper 510 is omitted. Therefore, in the case of a freezer, the rotation speeds of compressor 31 and blower 35 are controlled according to the set rank during the initial operation after defrosting.

[0152] In the above embodiment, the stored items stored in the refrigerator 1 are described as food, but this is not limited to this. For example, the stored items may be items collected from the natural world, such as raw meat from small animals that are not edible, or raw meat from animals used for experiments, such as cloned animals.

[0153] In addition, in the above embodiment, the first operation after defrosting is performed regardless of the time zone at the end of the defrosting operation. However, the first operation after defrosting may be performed only when the time zone at the end of the defrosting operation is a non-use time zone. In this case, if the time zone at the end of the defrosting operation is not a non-use time zone, the first operation after defrosting as in the prior art may be performed, or normal operation may be performed. In addition, in the above embodiment, the rotation speed of the compressor 31, the rotation speed of the blower 35, and the damper angle are changed in stages according to the set rank during the first operation after defrosting. However, it is only necessary to change at least one of the rotation speed of the compressor 31, the rotation speed of the blower 35, and the damper angle in stages according to the set rank.

[0154] Furthermore, in the above embodiment, a case where suppression of evaporation of moisture from stored items in the freezer compartment 12 is prioritized has been described as an example. However, suppression of evaporation of moisture from stored items in the refrigerator compartment 11 may also be prioritized. In this case, in step S96 of the initial post-defrost operation in the first embodiment, it is determined whether to terminate the initial post-defrost operation depending on whether the refrigerator compartment temperature Tr is equal to or lower than the lower limit (Trs-dθr) of the allowable range of the set temperature Trs. Furthermore, the angle θ of the damper 510 during the initial post-defrost operation is set to 90 degrees (fully open) for the lowest set rank SR1 and 0 degrees (fully closed) for the highest set rank SR10, with equal intervals between each set rank. Furthermore, in the second embodiment, the temperature rise rank is determined using the maximum temperature Trdmax of the refrigerator compartment temperature Tr during defrost operation. Furthermore, in embodiment 3, a storage item temperature sensor 135 for measuring the storage item temperature Tm is provided in the refrigerator compartment 11, and a determination is made as to whether or not to downgrade the rank based on the slope of the storage item temperature Tm and the slope of the refrigerator compartment temperature Tr.

[0155] Furthermore, Embodiments 1 to 3 can be combined as appropriate. For example, Embodiments 1 and 2 may be combined, and the rotation speeds of compressor 31 and blower 35 may be set using set ranks corresponding to the usage frequency rank and outdoor air temperature rank during the first operation after defrosting shown in FIG. 19 , and the angle of damper 510 may be set using set ranks corresponding to the temperature rise rank and outdoor air temperature rank shown in FIG. 25 . Alternatively, the rotation speeds of compressor 31 and blower 35 may be set using set ranks corresponding to the temperature rise rank and outdoor air temperature rank shown in FIG. 25 , and the angle of damper 510 may be set using set ranks corresponding to the usage frequency rank and outdoor air temperature rank during the first operation after defrosting shown in FIG. 19 .

[0156] Furthermore, in the first embodiment, the rank representing the heat load in the storage compartment is used when determining the setting rank for the first operation after defrosting. In the second embodiment, the rank representing the temperature rise during defrosting operation is used. However, the present invention is not limited to these. For example, a thermal camera may be installed in the storage compartment to determine the heat load in the storage compartment based on the amount and temperature of stored items in the storage compartment, and the ranking may be determined.

[0157] In the above embodiment, the temperature is increased by a fixed time "trun" during the first operation after defrosting. However, the time "trun" may be changed depending on the heat load or temperature change. For example, the time "trun" for a low frequency of use or a low temperature increase may be set to be longer than the time "trun" for a high frequency of use or a high temperature increase.

[0158] Furthermore, in the above embodiment, during the first operation after defrosting, the control parameters of the compressor 31, the blower 35, and the damper 510 are set to a single set rank and are increased in rank at the same time, but the present disclosure is not limited to this. For example, the compressor 31, the blower 35, and the damper 510 may each be set to a set rank and increased in rank at different times. In this case, it is desirable to increase the rank in the order of the compressor 31, the blower 35, and the damper 510.

[0159] REFRIGERATOR COMPONENTS 1, 1A Refrigerator, 2 Main body, 3 Cooler compartment, 6 Control device, 11 Refrigerating compartment, 12 Freezer compartment, 16 Partition member, 17 Open / close sensor, 18 Operation display unit, 18a Operation unit, 18b Display unit, 19 Outside air temperature sensor, 21 Outer box, 22 Inner box, 23 Heat insulating member, 30 Machine compartment, 31 Compressor, 32 Condenser, 33 Pressure reducing device, 34 Cooler, 34a Inlet, 34b Outlet, 35 Fan, 36 Cooler compartment temperature sensor, 41 Defrost heater, 42 Drain pipe, 43 Drain heater, 44 Drain pan, 51 First air duct, 52 Second air duct, 53 First return air duct, 54 Second return air duct, 61 Memory unit, 62 Cooling control unit, 63 Heater control unit, 64 Adjustment coefficient calculation unit, 65 Rank determination unit, 110 refrigerator compartment door, 111 shelf, 112 storage container, 113 refrigerator compartment temperature sensor, 120 freezer compartment door, 122 storage container, 123 freezer compartment temperature sensor, 135 stored item temperature sensor, 341 fin, 342 heat transfer tube, 343 connecting tube, 510 damper, 511 shaft, 600 processing circuit, 601 processor, 602 memory, 603 bus.

Claims

1. A cooling system comprising: a main body having a storage compartment and a cooler compartment; a door provided on the front of the storage compartment; a cooler disposed in the cooler compartment and generating cool air by heat exchange with a refrigerant; a blower that sends the cool air to the storage compartment; a compressor that sends the refrigerant to the cooler; an internal temperature sensor that measures the internal temperature of the storage compartment, which is the temperature of the storage compartment; and a control device that controls the compressor and the blower, wherein the control device performs a defrosting operation that stops the compressor and the blower and defrosts the cooler, and an initial post-defrost operation that is the first cooling operation after the defrosting operation is completed, and during the initial post-defrost operation, the control device determines an initial setting rank based on the outside air temperature and a rank that represents the amount of heat load in the storage compartment, and starts at least one of the compressor and the blower at a rotation speed that is set by the initial setting rank, A storage facility that increases the set rank every time a preset rank-up time elapses, thereby gradually increasing the rotation speed of at least one of the compressor and the blower.

2. A storage facility as described in claim 1, further comprising a damper provided in an air duct for sending the cold air to the storage chamber, wherein the control device sets the damper to an angle set by the initial set rank during the first operation after the defrosting, and increases the set rank each time the rank-up time elapses, thereby gradually changing the angle of the damper.

3. A storage facility as described in claim 2, which is equipped with an opening / closing sensor that detects the opening and closing of the door, and the rank representing the amount of heat load is a usage frequency rank for each time period determined based on the number of times the door is opened and closed.

4. A storage facility as described in claim 3, wherein the control device stores a table in which the set rank is set according to the frequency of use rank and an outside air temperature rank determined based on the outside air temperature.

5. A storage facility as described in claim 3 or 4, wherein the usage frequency rank is calculated by multiplying a first adjustment coefficient indicating the rate at which stored items are put into the storage room when the door is opened and closed, a second adjustment coefficient calculated from the temperature of the storage room when the door is opened and closed, the outside air temperature, and the cooler room temperature which is the temperature of the cooler room, the number of times the door is opened and closed for each time period, and the opening time of the door.

6. A storage facility described in any one of claims 1 to 5, wherein the rank representing the amount of thermal load is a temperature rise rank determined based on the maximum temperature inside the storage facility during the defrosting operation.

7. The storage facility according to claim 6, wherein the control device stores a table in which the set ranks are set according to the temperature rise rank and an outside air temperature rank determined based on the outside air temperature.

8. A storage facility as described in claim 4 or 7, wherein the control device stores a map in which at least one of the rotation speed of the compressor and the rotation speed of the blower is set for each set rank.

9. A storage facility as described in any one of claims 1 to 8, further comprising a storage item temperature sensor for measuring the temperature of the stored items contained in the storage chamber, wherein the control device calculates the gradient of the temperature inside the storage facility at a preset time and the gradient of the storage item temperature sensor during the first operation after the defrosting, and if the gradient of the temperature inside the storage facility is smaller than the gradient of the storage item temperature sensor, downgrades the setting rank and reduces the rotation speed of at least one of the compressor and the blower.

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