Household refrigerator

Abstract

To provide a household refrigerator that can store food while suppressing chilling damage and maintaining its quality. [Solution] In this embodiment, the household refrigerator 1 has a control unit 45 that repeatedly performs a refrigeration cooling operation to cool the refrigerated storage compartment and a freezing cooling operation to cool the freezer compartment, while repeatedly performing a cooling and preservation operation to adjust the refrigerated storage compartment to a first temperature above the freezing point, and a recovery operation to adjust the refrigerated storage compartment to a second temperature higher than the first temperature to recover from low-temperature damage to food. The control unit performs such a procedure that the total time for performing one cooling and preservation operation and one recovery operation is longer than the total time for performing one refrigeration cooling operation and one freezing cooling operation.

Description

Technical Field

[0001] Embodiments of the present invention relate to household refrigerators.

Background Art

[0002] Generally, when storing food, it is desirable to store it at a low temperature to maintain its quality. However, among foods, there are some, such as fresh fruits and vegetables like bananas, cucumbers, and eggplants, that suffer from disorders (low-temperature disorders) such as discoloration and depression of the fruit skin when exposed to low temperatures, and freshness may not be maintained simply by lowering the temperature.

[0003] Note that Patent Document 1 below discloses a refrigerator including a vegetable compartment for storing fresh fruits and vegetables and temperature control means for controlling the temperature inside the vegetable compartment, and the temperature control means controls the temperature of the vegetable compartment according to the growth period of the fresh fruits and vegetables stored in the vegetable compartment. The refrigerator of Patent Document 1 below aims to increase or maintain the sweetening components of fresh fruits and vegetables and does not consider low-temperature disorders occurring in foods.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Therefore, an object of the present invention is to provide a household refrigerator capable of storing foods while suppressing low-temperature disorders and maintaining quality.

Means for Solving the Problems

[0006] A household refrigerator according to one embodiment includes a refrigerated storage compartment cooled to a refrigeration temperature, a freezer compartment cooled to a freezing temperature, temperature control means for adjusting the temperatures of the refrigerated storage compartment and the freezer compartment, and a control unit for controlling the temperature control means. The control unit is capable of repeatedly performing a refrigeration cooling operation to cool the refrigerated storage compartment and a freezing cooling operation to cool the freezer compartment, while repeatedly performing a cooling and preservation operation to adjust the refrigerated storage compartment to a first temperature above the freezing temperature, and a recovery operation to adjust the refrigerated storage compartment to a second temperature higher than the first temperature to recover from low-temperature damage to the food. The control unit is capable of repeatedly performing a refrigeration cooling operation to cool the refrigerated storage compartment and a freezing cooling operation to cool the freezer compartment, while repeatedly performing a cooling and preservation operation to cool the refrigerated storage compartment to a first temperature above the freezing temperature, and is capable of repeatedly performing a cooling and preservation operation to cool the food to a second temperature higher than the first temperature, and is capable of performing a recovery operation to recover from low-temperature damage to the food. [Brief explanation of the drawing]

[0007] [Figure 1] Cross-sectional view of a household refrigerator of one embodiment of the present invention. [Figure 2] Figure 1: Enlarged cross-sectional view of the main part of a household refrigerator. [Figure 3] Block diagram showing the electrical configuration of a household refrigerator (Figure 1) [Figure 4] Enlarged cross-sectional view of the main parts of a household refrigerator, as shown in modification example 2. [Figure 5] Enlarged cross-sectional view of the main part of a household refrigerator, as shown in modification example 4. [Figure 6] Enlarged cross-sectional view of the main part of a household refrigerator, example of modification 6. [Modes for carrying out the invention]

[0008] Embodiments will be described with reference to the drawings. The following embodiments are illustrative and the scope of the invention is not limited thereto. The following embodiments can be carried out in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. The following embodiments and their variations are included in the scope of the invention as described in the claims and its equivalents.

[0009] In the following explanation, left-right, front-back, and up-down directions refer to the directions when viewing the refrigerator from the front, with the left-right direction corresponding to the width of the refrigerator. Also, unless otherwise specified, right, left, up, down, front, back, far, back, and front refer to the position or side of the refrigerator when viewed from the front, and for the refrigerator door, it refers to the position or side when the door is closed and viewed from the front.

[0010] (1) Configuration of household refrigerator 1 The household refrigerator 1 (hereinafter sometimes referred to as refrigerator 1) according to this embodiment includes a refrigerator body 2 consisting of an insulated box that opens to the front, as shown in Figure 1. The refrigerator body 2 is constructed with an insulating material such as vacuum insulation material or foam insulation material in the insulating space formed between the outer box made of steel plate and the inner box made of synthetic resin. The refrigerator body 2 has multiple storage spaces inside the inner box, and the storage spaces are divided vertically by an insulating partition wall 3.

[0011] The space above the insulated partition wall 3 is a refrigerated space cooled to a refrigeration temperature range (for example, 1-5°C). The refrigerated space partitioned above the insulated partition wall 3 is further divided vertically by a partition plate 4, with a refrigerator compartment 10 provided above the partition plate 4 and a vegetable compartment 11 provided below the partition plate 4.

[0012] The refrigerator compartment 10 is equipped with multiple shelves 5. Below the lowest shelf 5 is a chilled compartment, which is kept at a particularly low temperature within the refrigerator compartment 10. The front opening of the refrigerator compartment 10 is equipped with a hinged, pivotable refrigerator door 15. On the front of the refrigerator door 15 is an operation display unit 6 that receives settings from the user for the refrigerator 1 and displays the settings status of the refrigerator 1.

[0013] A refrigerator temperature sensor 60 for measuring the internal temperature of the refrigerator compartment 10 is provided on the rear of the refrigerator compartment 10. In addition, a door sensor 61 for detecting the opening and closing of the refrigerator compartment door 15 is provided on the periphery of the front opening of the refrigerator compartment 10.

[0014] The front opening of the vegetable compartment 11 is closed by a pull-out vegetable compartment door 16. A pair of left and right support frames for holding the storage container 20 are fixed to the inside of the vegetable compartment door 16, and the storage container 20 is pulled out of the compartment when the door is opened. The specific configuration of the storage container 20 will be described in detail later.

[0015] The space below the insulated partition wall 3 is a freezing space cooled to a freezing temperature range (for example, below -17°C). Within the freezing space, an ice-making room (not shown) equipped with an automatic ice maker and a first freezing room 13 are located on the left and right sides, with a second freezing room 14 located below them via a partition plate 7.

[0016] The openings of the ice-making compartment, the first freezer compartment 13, and the second freezer compartment 14 are closed by pull-out doors 18 and 19, similar to the vegetable compartment 11. Storage containers 21 and 22 are held in a pair of left and right support frames fixed to the back side of each door 18 and 19, and are configured to be pulled out of the compartment when the door is opened. A freezer temperature sensor 62 for measuring the internal temperature of the second freezer compartment 14 is provided on the back of the second freezer compartment 14.

[0017] Behind the storage compartments in the refrigerated temperature zone (refrigerated compartment 10 and vegetable compartment 12), there is a separate refrigerated cooler compartment 33 that houses a refrigerated cooler 30, a refrigerated fan 31, and a drain pan 32. The refrigerated cooler 30 cools the air in the refrigerated cooler compartment 33 to generate cold air, and the refrigerated fan 31 supplies this cold air to the refrigerated compartment 10 and the vegetable compartment 11 via a duct 34, thereby cooling the food stored in the vegetable compartment 10 and the vegetable compartment 11. In other words, the refrigerated cooler 30 functions as a cooling unit that cools the food stored in the refrigerated compartment 10 and the food stored in the storage containers 20 of the vegetable compartment 11.

[0018] The drain pan 32 receives condensation water (defrost water) generated from the refrigerator cooler 30 during defrosting operation. The condensation water accumulated in the drain pan 32 is discharged via a drain hose (not shown) to an evaporation tray 37 located in the machine room 36 at the lower rear of the refrigerator body 2.

[0019] At the back of the storage compartments (ice-making compartment, first freezer compartment 13, and second freezer compartment 14) in the freezing temperature zone, a freezer cooler chamber 42 is partitioned off to house a freezer cooler 38, a freezer blower 39, a defrost heating section 40, and a drain trough 41. The freezer cooler 38 cools the air in the freezer cooler chamber 42 to generate cold air, and the generated cold air is supplied by the freezer blower 39 to the ice-making compartment, the first freezer compartment 13, and the second freezer compartment 14 in the freezing temperature zone via a duct 43. In addition, dampers with adjustable openings may be provided at the air outlets where cold air blows out into the ice-making compartment and the first freezer compartment 13, enabling independent temperature control of the ice-making compartment and the first freezer compartment 13 from the second freezer compartment 14.

[0020] The refrigerator cooler 30 and the freezer cooler 38 constitute a refrigeration cycle together with a compressor 44, a condenser (not shown), and a switching valve 46 (see Fig. 3) housed in the machine room 36. In the refrigeration cycle, the refrigerant discharged from the compressor 44 is supplied by the switching valve 46 to one of the refrigerator cooler 30 and the freezer cooler 38. As a result, one of the refrigerator cooler 30 and the freezer cooler 38 to which the refrigerant is supplied is cooled to a predetermined temperature.

[0021] Also, on the outside of the refrigerator body 2 (outside the cabinet), for example, at the rear part of the upper surface of the ceiling wall of the refrigerator body 2, a control unit 45 composed of a control board on which a microcomputer or the like for controlling the refrigerator 1 is mounted is provided.

[0022] (2) Structure of the storage container 20 As shown in Fig. 2, the storage container 20 provided in the vegetable compartment 12 is a resin molded body and includes a lower container 23 provided over substantially the entire width of the vegetable compartment 12 and an upper container 50 provided above the lower container 23.

[0023] The lower container 23 has a bottomed box shape that is open upward and is surrounded by a front wall, a rear wall, and left and right side walls. The accommodation depth of the lower container 23 is provided deeper than that of the upper container 50. The inside of the lower container 23 is partitioned front and back by a front and rear partition wall 27 that extends in the width direction. This front and rear partition wall 27 is provided so as to connect the inner surfaces of the left and right side walls of the lower container 23. A lower front container 23a is formed on the front side of the front and rear partition wall 27, and a lower rear container 23b is formed on the rear side.

[0024] The lower container 23 is held by a pair of left and right support frames 24 fixed to the back side of the vegetable compartment door 16, and is configured to be pulled out of the compartment when the vegetable compartment door 16 is opened. The upper ends of the left and right side walls of the lower container 23 form a sliding surface 28 on which the lower legs 53 of the upper container 50 are placed and which slide in the front-rear direction.

[0025] The front of the upper opening of the lower rear container 23b is covered by the upper container 50 when the vegetable compartment door 16 is closed (with the storage container 20 stored inside the vegetable compartment 11), as shown in Figures 1 and 2. The rear of the upper opening of the lower rear container 23b is covered by the sheet storage case 102 which houses the functional sheet 100.

[0026] The functional sheet 100 comprises a moisture-permeable sheet and a breathable sheet, and is installed inside the sheet storage case 102. The moisture-permeable sheet is a sheet material that is waterproof and moisture-permeable, for example, a porous sheet material having many pores with a diameter of 0.5 μm to 3 μm, which allows water vapor particles and oxygen molecules to pass through but blocks water particles larger than the pores. Also, because it is porous, it has a predetermined wind-blocking property that restricts the flow of air (wind). For example, a moisture-permeable waterproof sheet made by laminating polyester long-fiber nonwoven fabric and polyethylene porous film can be used as the moisture-permeable sheet. The breathable sheet is made of a sheet material that has breathability, such as a nonwoven fabric sheet, a woven fabric, or a flexible porous resin sheet.

[0027] The upper container 50, located above the lower container 23, is a bottomed box-shaped structure with an upward opening, surrounded by a front wall, a rear wall, and left and right side walls. The top opening 51 on the top surface of the upper container 50 is an opening for loading and unloading stored items inside, and is closed by a lid 80 that can be opened and closed. The internal space of the upper container 50 constitutes a fruit and vegetable storage room separated from the vegetable compartment 11, and the bottom surface 50a of the upper container 50 serves as a place to put food.

[0028] The upper container 50 is positioned close to the lower part of the partition plate 4 that separates the refrigerator compartment 10 and the vegetable compartment 12, and is installed in the vegetable compartment 12 so that it can be pulled out of the refrigerator independently of the lower container 23 by sliding in the front-rear direction between the inner box rails 25 provided on the left and right inner walls of the vegetable compartment 12 and the sliding surfaces 28 provided on the upper ends of the left and right side walls of the lower container 23.

[0029] On the outer sides of the left and right side walls of the upper container 50, upper container legs 52 are mounted on inner box rails 25 and slide along them in the front-rear direction, and lower container legs 53 are mounted on sliding surfaces 28 provided on the lower container 23 and slide along them in the front-rear direction, protruding outward in the width direction. The upper container legs 52 and lower container legs 53 support the upper container 50 so that it can move in the front-rear direction.

[0030] The front end of the bottom wall of the upper container 50 is provided with a projection 55 that protrudes downward. When the vegetable compartment door 16 is closed from the state in which the upper container 50 is pulled out to the front of the vegetable compartment 12 with the door open, the front and rear partition walls 27 of the lower container 23 come into contact with the projection 55 of the upper container 50, causing the upper container 50 to move backward.

[0031] As shown in Figure 2, the lid 80 comprises a plate portion 81, support portions 84 and 85, a heating portion 86, and a temperature detection portion 87, and is attached to the partition plate 4 that constitutes the ceiling surface of the vegetable compartment 12.

[0032] The plate portion 81 is substantially flat in shape, covering and closing the entire upper opening 51 of the upper container 50. The lower peripheral edge of the plate portion 81 is flat and is in surface contact with the entire peripheral edge of the upper opening 51 of the upper container 50.

[0033] The support parts 84 and 85 comprise a front support part 84 located in front of the center of the plate part 81 in the front-rear direction, and a rear support part 85 located behind the front support part 84. They engage with the partition plate 4 that separates the refrigerator compartment 10 and the vegetable compartment 12, supporting the plate part 81 so that it can move up and down within the vegetable compartment 12.

[0034] The heating unit 86 and the temperature detection unit 87 are attached to the plate unit 81. The heating unit 86 heats the food stored in the upper container 50 from above, and the temperature detection unit 87 detects the temperature of the food stored in the upper container 50. The heating unit 86 functions as a temperature control means to adjust the temperature of the food stored in the upper container 50 together with the refrigerator 30.

[0035] Various heat sources can be used in the heating section 86, but it is preferable to use a heat source that emits radiant heat, such as a halogen heater or a ceramic heater, to heat the food stored in the upper container 50.

[0036] Furthermore, an insulating material 88 may be provided on the lid 80 to cover the heating unit 86 from the outside of the upper container 50 (above the heating unit 86 in this embodiment). This prevents heat from the heating unit 86 from leaking to the outside of the upper container 50.

[0037] In this upper container 50, to open the top opening 51 from the closed state of the vegetable compartment door 16 as shown in Figure 2, first, the vegetable compartment door 16 is opened. Since the upper legs 52 of the container are placed on the inner box rail 25 and the upper container 50 is supported, when the vegetable compartment door 16 is opened, the lower container 23 is pulled out of the compartment, but the upper container 50 remains in the vegetable compartment 12 with the top opening 51 closed by the lid 80.

[0038] Then, when the upper container 50 stored in the vegetable compartment 12 is pulled forward, the upper container 50 is pulled out of the compartment. Since the lid 80 is supported so as to be able to move up and down by the front support portion 84 and the rear support portion 85, when the upper container 50 is pulled out of the compartment, the upper end of the upper container 50 comes into contact with the front positioning portion 82 provided on the lid 80, and the upper container 50 moves forward while the front end of the lid 80 is lifted upward.

[0039] Next, in order to store the upper container 50, which has been pulled out of the refrigerator, into the vegetable compartment 12, the vegetable compartment door 16 is closed. As a result, the front and rear partition walls 27 of the lower container 23 come into contact with the projection 55 of the upper container 50, moving the upper container 50 backward. At this time, an inclined portion (not shown) provided at the rear end of the upper container 50 scoops up the front positioning portion 82 and guides it to the upper surface of the upper container 50. After that, the upper container 50 moves backward while sliding along the lower surface of the lid 80, thereby closing the upper opening 51 of the upper container 50 with the lid 80.

[0040] (3) Control of Refrigerator 1 As shown in Figure 3, the control unit 45, located at the top of the refrigerator body 2, is electrically connected to electrical components installed in the refrigerator body 2, such as the operation display unit 6, refrigerator fan 31, freezer fan 39, defrost heating unit 40, compressor 44, switching valve 46, refrigerator temperature sensor 60, door sensor 61, freezer temperature sensor 62, heating unit 86, and temperature detection unit 87. The control unit 45 then controls the overall operation of the refrigerator 1 based on a control program pre-stored in memory, when it receives signals from various sensors or signals from a user communication terminal that can communicate with the operation display unit 6 or the refrigerator 1 through user operation.

[0041] Specifically, the control unit 45 switches between refrigeration cooling operation and freezing cooling operation and performs them alternately. When predetermined defrosting start conditions are met, it performs defrosting operation to melt and remove frost attached to the refrigeration cooler 30 and freezing cooler 38. In addition, when predetermined conditions are met, the control unit 45 performs fruit and vegetable preservation operation.

[0042] In this embodiment, the refrigerator 1 is designed to continuously operate either the refrigeration operation or the freezing operation. However, the refrigeration operation and freezing operation may be stopped when certain conditions are met, such as during the execution of the second defrosting operation described later, or when the temperature of both the refrigerated and freezing compartments falls below a predetermined temperature.

[0043] (3-1) Refrigeration operation When the refrigeration start conditions are met, the control unit 45 drives the compressor 44 at a predetermined frequency, opens the outlet of the switching valve 46 on the refrigerant flow path side to allow refrigerant to flow to the refrigerated cooler 30, and then rotates the refrigerated blower 31 to start the refrigeration operation. An example of a refrigeration start condition is when the temperature detected by the refrigerated temperature sensor 60 becomes equal to or above the ON temperature (for example, 5°C) set for the refrigerated space.

[0044] During refrigeration operation, the low-pressure, low-temperature refrigerant flowing into the refrigerator 30 vaporizes to generate cold air. The generated cold air is circulated within the refrigerator compartment 10 and the vegetable compartment 11 by the airflow of the refrigerator fan 31, cooling the refrigerator compartment 10 and the lower container 23 and upper container 50 in the vegetable compartment 11 to a predetermined refrigerated temperature range.

[0045] Specifically, the rotation of the refrigerated fan 31 causes the cold air generated in the refrigerated cooler 30 to be supplied to the refrigerator compartment 10 from the outlet 34a of the duct 34, thereby cooling the refrigerator compartment 10. A portion of the cold air that has flowed through the refrigerator compartment 10 flows into the return duct from the intake port provided at the rear of the partition plate 4 and returns to the refrigerated cooler compartment 33, while the remaining air flows into the vegetable compartment 11 through the connecting passage 4a provided in the partition plate 4. The cold air that has flowed into the vegetable compartment 11 flows around the lower container 23 and the upper container 50, indirectly cooling the inside of the lower container 23 and the upper container 50, and then returns to the refrigerated cooler 30 from the intake port provided at the rear of the vegetable compartment 11 through the return duct, is cooled again, and then is blown back into the refrigerator compartment 10 from the outlet 34a.

[0046] Then, if the refrigeration cooling termination condition is met during the refrigeration cooling operation, the control unit 45 terminates the refrigeration cooling operation. An example of a refrigeration cooling termination condition is when the temperature detected by the refrigeration temperature sensor 60 reaches the OFF temperature set for the refrigerated space (for example, 2°C).

[0047] When the refrigeration operation is finished, the control unit 45 drives the compressor 44 at a predetermined frequency, opens the outlet of the switching valve 46 on the refrigerant flow path side to allow refrigerant to flow to the refrigeration cooler 38, and then rotates the refrigeration blower 39 to start the refrigeration operation.

[0048] (3-2) Refrigeration operation During refrigeration operation, the low-pressure, low-temperature refrigerant flowing into the refrigeration cooler 38 vaporizes to generate cold air. The generated cold air circulates through the ice-making compartment, the first freezing compartment 13, and the second freezing compartment 14 by the blowing action of the refrigeration blower 39, cooling the ice-making compartment, the first freezing compartment 13, and the second freezing compartment 14 to a predetermined refrigeration temperature range.

[0049] The cold air that circulates within the ice-making compartment, the first freezing compartment 13, and the second freezing compartment 14 returns to the refrigeration cooler 38 through a return duct via an intake port located at the rear of the second freezing compartment 14, is cooled, and then blown back into the ice-making compartment, the first freezing compartment 13, and the second freezing compartment 14.

[0050] Then, if the refrigeration termination condition is met during the execution of the refrigeration operation, the control unit 45 terminates the refrigeration operation. An example of a refrigeration termination condition is when the temperature detected by the refrigeration temperature sensor 62 reaches the OFF temperature set for the refrigerated space (for example, -21°C). There are cases where this has happened.

[0051] Then, when the freezing and cooling operation is finished, the control unit 45 starts the refrigeration and cooling operation.

[0052] (3-3) Defrosting operation Refrigerator 1 switches between refrigeration and freezing operations, and when the predetermined defrosting start conditions are met, it executes the first defrosting operation and the second defrosting operation.

[0053] The first defrosting operation removes frost accumulated on the refrigerator cooler 30 by melting it, and humidifies the refrigerator space by supplying the moisture from the melted frost to the refrigerator space. Specifically, the control unit 45 drives the refrigerator fan 31 while stopping the supply of refrigerant to the refrigerator cooler 30 by blocking the outlet of the switching valve 46 on the refrigerant flow path side or stopping the compressor 44.

[0054] As a result of these controls, the air in the refrigerated space exchanges heat with the frost-covered refrigerator cooler 30 and is then returned to the refrigerator compartment 10 and vegetable compartment 11. This raises the temperature of the refrigerator cooler 30, melting the frost that has accumulated on it, and vaporizes the water from the melted frost, which is then blown into the refrigerator compartment 10 and vegetable compartment 11. This supplies humidified air, which has a higher relative humidity than the cold air blown into the refrigerator compartment 10 and vegetable compartment 11 during the refrigeration operation described above, thus humidifying the refrigerator compartment 10 and vegetable compartment 11.

[0055] The second defrosting operation removes frost accumulated on the refrigeration unit 38 by melting it. Specifically, the control unit 45 stops the supply of refrigerant to the refrigeration unit 38 by blocking the outlet of the switching valve 46 on the refrigeration refrigerant flow path side or by stopping the compressor 44, while simultaneously stopping the refrigeration blower 39 and energizing the defrosting heating unit 40. Through these controls, the refrigeration unit 38 is heated by the heat from the defrosting heating unit 40, melting the frost accumulated on the refrigeration unit 38. The defrost water generated from the melting frost is received by the drain gutter 41 and discharged into the evaporation tray 37 located in the machine room 36.

[0056] (3-4) Produce preservation operation In refrigerator 1, a produce preservation operation is performed, which alternates between cooling and preservation operation and recovery operation in the upper container 50 that constitutes the produce storage compartment. The produce preservation operation may be performed when predetermined start conditions are met, such as when the user performs a predetermined operation from the operation display unit 6 or user communication terminal to instruct the execution of the produce preservation operation, or when the control unit 45 detects that food has been placed in the upper container 50. Alternatively, the produce preservation operation may be performed continuously while refrigerator 1 is powered on.

[0057] The cooling and preservation operation is performed to cool the food stored in the upper container 50. When the cooling and preservation operation is performed, the control unit 45 indirectly cools the inside of the upper container 50 with cold air supplied to the vegetable compartment 11, and drives the heating unit 86 as needed, so that the temperature of the food detected by the temperature detection unit 87 becomes a first temperature Te1.

[0058] The control unit 45 performs a cooling and storage operation for a first hour Ti1, thereby cooling the food stored in the upper container 50 to a first temperature Te1 for a first hour Ti1, after which it terminates the cooling and storage operation and starts the recovery operation.

[0059] The recovery operation is an operation that heats the food stored in the upper container 50 to a second temperature Te2 which is higher than the first temperature Te1, and is an operation to recover from low-temperature damage that occurred to the food stored in the upper container 50 due to the cooling and storage operation. When the recovery operation is performed, the control unit 45 drives or stops the heating unit 86 so that the temperature of the food detected by the temperature detection unit 87 becomes the second temperature Te2 which is higher than the first temperature Te1.

[0060] The control unit 45 performs a recovery operation for a second time Ti2, thereby maintaining the food stored in the upper container 50 at a second temperature Te2 for a second time Ti2. After this, it terminates the recovery operation and starts a cooling and preservation operation. Thereafter, it alternates between a cooling and preservation operation lasting for a first time Ti1 and a recovery operation lasting for a second time Ti2.

[0061] Then, if the termination conditions are met during the execution of the produce preservation operation, the control unit 45 terminates the produce preservation operation. Examples of termination conditions include, for example, when the user performs a predetermined operation from the operation display unit 6 or user communication terminal to instruct the termination of the produce preservation operation, or when the control unit 45 detects that food has been removed from the upper container 50.

[0062] Furthermore, even during the cooling and storage operation and the recovery operation, the control unit 45 switches between the refrigeration cooling operation and the freezing cooling operation and executes them alternately. Therefore, even when the cooling and storage operation or the recovery operation is in progress, as long as the refrigeration cooling operation is running, the cold air generated by the refrigerator 30 is supplied to the vegetable compartment 11 via the refrigerator compartment 10, and the inside of the upper container 50 is indirectly cooled.

[0063] The first temperature Te1 set during the cooling and storage operation can be set to be above the freezing temperature Tf (for example, Tf = 0°C) of the food stored in the upper container 50, and below the critical temperature Tc of the food. The second temperature Te2 set during the recovery operation can be set to be higher than the critical temperature Tc of the food stored in the upper container 50.

[0064] The critical temperature Tc of a food can be determined as follows: Prepare mannitol solutions at temperatures ranging from 1°C to 20°C in 1°C increments. Immerse the food tissue in each solution for 30 minutes and measure the amount of ions leaking from the food tissue into the solution using an electrical conductivity meter to determine the electrolyte leakage rate at each temperature. Then, create an Arrhenius plot of the electrolyte leakage rate from the electrolyte leakage rates at each temperature, and the inflection point of this plot can be identified as the critical temperature Tc of the food.

[0065] In addition, it is assumed that household refrigerators 1 will store various foods with different critical temperatures Tc. Therefore, the critical temperature Tc may be set to a temperature selected from 8 to 15°C. In this case, the critical temperature Tc may be set to a temperature higher than the lowest temperature reached by the front end of the top shelf 5 of the refrigerator compartment 10 when the cooling intensity of the refrigerator compartment 10 is set to the lowest setting, or to a temperature higher than the upper front end of the vegetable compartment 11 when the cooling intensity of the refrigerator compartment 10 is set to the lowest setting, or to a temperature higher than the ON temperature set as the refrigeration start condition.

[0066] Furthermore, when selecting a critical temperature Tc from 2 to 15°C, the user may set the temperature selected by the user as the critical temperature Tc. Alternatively, a correspondence table between food and critical temperature Tc may be pre-stored in the refrigerator 1 or a server device or user communication terminal that can communicate with the refrigerator 1, and the critical temperature Tc corresponding to the food selected by the user from the operation display unit 6 or user communication terminal may be read from the correspondence table and set as the critical temperature Tc.

[0067] It is preferable to set the first temperature Te1 and the second temperature Te2 such that the temperature difference Δ2 (=Te2-Tc) between the second temperature Te2 and the critical temperature Tc is smaller than the temperature difference Δ1 (=Tc-Te1) between the first temperature Te1 and the critical temperature Tc. For example, if the critical temperature Tc is 10°C, the first temperature Te1 can be set to 2-5°C, and the second temperature Te2 can be set to 11-14°C.

[0068] The recovery operation time (second time) Ti2 is preferably the same as the cooling and storage operation time (first time) Ti1, or longer than the cooling and storage operation time Ti1, and it is preferable that the continuous cooling and storage operation time is 24 hours or less. For example, the first time Ti1 can be set to 10 hours or more and 24 hours or less, and the second time Ti2 can be set to 18 hours or more and 48 hours or less.

[0069] Furthermore, it is preferable that the repeat cycle of cooling and storage operation and recovery operation, that is, the sum of the time Ti1 for performing one cooling and storage operation and the time Ti2 for performing one recovery operation (Ti1 + Ti2), is longer than the repeat cycle of refrigeration operation and freezing operation, that is, the sum of the execution times for one refrigeration operation and freezing operation.

[0070] (4) Effects In this embodiment, the refrigerator 1 performs a cooling and storage operation to cool the upper container 50, and a recovery operation to maintain the upper container 50 at a higher temperature than during the cooling and storage operation to recover from low-temperature damage to the food stored in the upper container 50. As a result, it is possible to suppress the deterioration of freshness while suppressing low-temperature damage to the food, and to store food while maintaining its quality.

[0071] In this embodiment, since the temperature difference between the temperature Te2 during recovery operation and the critical temperature Tc is smaller than the temperature difference between the temperature Te1 during cooling and storage operation and the critical temperature Tc, low-temperature damage can be suppressed without unnecessary heating inside the refrigerator 1.

[0072] In this embodiment, the execution time Ti2 of the recovery operation is equal to or longer than the execution time Ti1 of the cooling and storage operation, so that the time necessary to recover from low-temperature damage to the food can be secured.

[0073] In this embodiment, the heating unit 86 heats the food stored in the upper container 50 by radiant heat, which suppresses the temperature rise inside the upper container 50 and allows for a quick transition from recovery operation to cooling and storage operation.

[0074] In this embodiment, since the fruit and vegetable preservation operation is performed in the upper container 50, which is located on the upper side of the two upper and lower containers 23, 50 provided in the vegetable compartment 11, the heat generated during the recovery operation is less likely to leak to the lower container 23, and the stored items in the lower container 20 can be cooled to the desired temperature even while the recovery operation is in progress.

[0075] (5) Example of change Next, examples of modifications to the above embodiment will be described. Any one of the following examples of modifications may be applied to the above embodiment, or two or more of the following examples may be selected and applied. However, various other modifications are possible, and the scope of the invention is not limited to the above embodiment and the following examples of modifications. In the figures showing the examples of modifications, the same reference numerals are used for the same parts as in Figure 2.

[0076] (5-1) Example of change 1 In the above embodiment, the case in which the fresh produce preservation operation is performed in the upper container 50 has been described, but the fresh produce preservation operation may also be performed by providing a heating unit in the chilled compartment or the first freezer compartment 13, etc., of the refrigerator compartment 10.

[0077] (5-2) Example of change 2 In the above embodiment, the heating element 86 is provided on the lid 80 above the bottom surface 50a of the upper container 50 which constitutes the food placement section. However, as shown in Figure 4, the heating element 186 may be provided below the bottom surface 50a. If the heating element 186 is provided below the bottom surface 50a of the upper container 50, an insulating material 188 may be provided to cover the heating element 186 from below.

[0078] As shown in this modified example, by providing a heating element 186, heat from the heating element 186 can be transferred to the food through the bottom surface 50a of the upper container 50 that comes into contact with the food, thereby suppressing the heating of the air inside the refrigerator.

[0079] Furthermore, by covering the heating section 186 from below with the insulating material 188, it is possible to prevent heat from the heating section 86 from leaking to the outside of the upper container 50.

[0080] (5-3) Example of modification 3 The heating unit 86 for heating the upper container 50 does not have to be positioned so as to be directly opposite the bottom surface 50a of the upper container 50. For example, the heating unit 86 may be provided on the upper part of the front wall, rear wall, or left and right side walls of the upper container 50. Alternatively, the heating unit may be provided at a location away from the upper container 50, such as the machine room 36, and the warm air generated by the heating unit may be supplied into the upper container 50 to heat the food stored in the upper container 50 to a second temperature Te2.

[0081] (5-4) Example of modification 4 In the refrigerator 1 of the above embodiment, when the heating unit 86 emits radiant heat to heat the food stored in the upper container 50, a reflecting unit 110 that reflects radiant heat may be provided in the upper container 50 at a position opposite to the heating unit 86, as shown in Figure 5.

[0082] In this case, the radiant heat emitted from the heating unit 86 is less likely to leak out of the upper container 50, and the food stored in the upper container 50 can be heated efficiently.

[0083] (5-5) Example of change 5 In the refrigerator 1 of the above embodiment, the first defrost operation and the second defrost operation may not be performed during the cooling and storage operation, but the first defrost operation and the second defrost operation may be performed during the recovery operation.

[0084] In such cases, the upper container 50 can be cooled without being affected by the heat generated by the first and second defrosting operations while the cooling and storage operation is in progress. Furthermore, the first and second defrosting operations, which tend to raise the temperature inside the refrigerator, can be performed while the recovery operation, which tends to raise the internal temperature of the upper container 50, is in progress. As a result, the heat generated during the fruit and vegetable storage operation and defrosting operation is not wasted, and the fruit and vegetable storage operation and defrosting operation can be performed efficiently.

[0085] (5-6) Example of modification 6 In the refrigerator 1 of the above embodiment, as shown in Figure 6, an opening 120 may be provided in the upper container 50 to introduce air from the vegetable compartment 11, and the air that has exchanged heat with the refrigerator cooler 30 may be supplied to the inside of the upper container 50.

[0086] In this case, since cold air from the vegetable compartment 11 can be introduced into the upper container 50, the inside of the upper container 50 can be quickly cooled to the first temperature Te1 during the cooling and storage operation.

[0087] Furthermore, in this modified example, the opening 120 may be covered with a functional sheet 122 similar to the functional sheet 100 provided at the upper opening of the lower rear container 23b. This prevents the cold air supplied to the vegetable compartment 11 from flowing forcefully into the upper container 50, thus preventing the food in the upper container 50 from being exposed to the cold air and drying out.

[0088] (5-7) Example of change 7 In the refrigerator 1 of the above embodiment, the air generated during the first defrosting operation, which has a higher relative humidity than the cold air blown to the refrigerator compartment 10 and the vegetable compartment 11 during the refrigeration cooling operation, may be supplied to the inside of the upper container 50.

[0089] As shown in this example of modification, by supplying the highly humidified air generated during the first defrosting operation to the upper container 50, it is possible to prevent the food from drying out due to the temperature rise inside the upper container 50 during the recovery operation.

[0090] The timing for supplying the air generated during the first defrosting operation to the upper container 50 can be arbitrarily set, such as when transitioning from cooling and storage operation to recovery operation, during recovery operation, during cooling and storage operation, when transitioning from rotation operation to cooling and storage operation, or when the fruit and vegetable storage operation is stopped. However, it is preferable to supply the air generated during the first defrosting operation to the upper container 50 when transitioning from cooling and storage operation to recovery operation or during recovery operation, as these are times when food tends to dry out. [Explanation of symbols]

[0091] 1...Refrigerator, 2...Refrigerator body, 3...Insulated partition wall, 4...Partition plate, 5...Shelf, 10...Refrigerator compartment, 11...Vegetable compartment, 13...First freezer compartment, 14...Second freezer compartment, 20...Storage container, 23...Lower container, 30...Refrigerator cooler, 31...Refrigerator fan, 33...Refrigerator cooler compartment, 38...Freezer cooler, 39...Freezer fan, 44...Compressor, 45...Control unit, 50...Upper container, 80...Lid, 81...Plate section, 82...Front support section, 86...Heating section, 87...Temperature detection section

Claims

1. The system comprises a refrigerated storage chamber cooled to a refrigeration temperature, a freezer chamber cooled to a freezing temperature, temperature control means for adjusting the temperatures of the refrigerated storage chamber and the freezer chamber, and a control unit for controlling the temperature control means. The control unit, The system can repeatedly perform a refrigeration operation to cool the refrigerated storage chamber and a freezing operation to cool the freezer chamber, while simultaneously performing a cooling and preservation operation to adjust the refrigerated storage chamber to a first temperature above the freezing point, and a recovery operation to adjust the refrigerated storage chamber to a second temperature higher than the first temperature to recover from low-temperature damage to the food. A household refrigerator that controls itself so that the total time for performing one cooling and storage operation and the time for performing one recovery operation is longer than the total time for performing one refrigeration operation and the time for performing one freeze operation.

2. The household refrigerator according to claim 1, wherein the temperature control means comprises a cooling unit for cooling the food and a heating unit for heating the food, and the heating unit is provided on the ceiling of the refrigerated storage compartment.

3. The household refrigerator according to claim 1, wherein the freezer compartment is located below the refrigerated storage compartment via an insulating partition wall.

4. The temperature control means comprises a cooling unit for cooling the food and a heating unit for heating the food. The household refrigerator according to any one of claims 1 to 3, wherein the control unit performs a defrosting operation to remove frost that has accumulated on the cooling unit during the execution of the recovery operation.

5. A household refrigerator according to any one of claims 1 to 4, wherein humidified air is supplied to the refrigerated storage compartment when transitioning from the cooling and storage operation to the recovery operation.

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