household refrigerator

Abstract

To provide a household refrigerator that can store food while restraining a low-temperature injury, and keeping quality.MEANS FOR SOLVING THE PROBLEM: A refrigerator 1 according to an embodiment comprises a storage chamber 50, temperature adjustment means for adjusting the temperature of food housed in the storage chamber 50, and a control part 45 for controlling the temperature adjustment means. The control part 45 executes cooling preservation operation for cooling the food housed in the storage chamber 50 to a first temperature Te1, and a recovery operation for heating the food housed in the storage chamber 50 to a second temperature Te2 higher than the first temperature Te1 to make a recovery from a low-temperature injury having occurred in the food.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a domestic refrigerator. [Background technology]

[0002] Generally, it is best to store food at low temperatures to maintain its quality. However, some foods, such as fruits and vegetables like bananas, cucumbers, and eggplants, can suffer damage (chilling injury) such as discoloration or denting of the skin when exposed to low temperatures, and so keeping them cold alone may not be enough to maintain their freshness.

[0003] Patent Document 1 below discloses a refrigerator that includes a vegetable compartment for storing fruits and vegetables and a temperature control means for controlling the temperature in the vegetable compartment, where the temperature control means controls the temperature in the vegetable compartment depending on the growing season of the fruits and vegetables stored in the vegetable compartment. The refrigerator in Patent Document 1 below aims to increase or maintain the sweet components in the fruits and vegetables, and does not take into consideration low-temperature damage that may occur to food. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-198097 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, an object of the present invention is to provide a household refrigerator that can prevent low-temperature damage and store food while maintaining its quality. [Means for solving the problem]

[0006] In one embodiment, a household refrigerator includes a storage compartment, a temperature adjustment means for adjusting the temperature of food stored in the storage compartment, and a control unit for controlling the temperature adjustment means, wherein the control unit executes a cooling and preservation operation for cooling the food to a first temperature, and a recovery operation for heating the food to a second temperature higher than the first temperature to recover from low-temperature damage caused to the food. The first temperature is a temperature equal to or higher than the freezing temperature of the food and equal to or lower than a critical temperature, the second temperature is higher than the critical temperature, the temperature difference between the second temperature and the critical temperature is smaller than the temperature difference between the first temperature and the critical temperature, and the cooling preservation operation and the recovery operation are alternately repeated at a temperature equal to or higher than 0°C. It is something. [Brief explanation of the drawings]

[0007] [Figure 1] Cross-sectional view of a home refrigerator according to one embodiment of the present invention. [Figure 2] Enlarged cross-sectional view of the main part of the household refrigerator in Figure 1 [Figure 3] Block diagram showing the electrical configuration of the household refrigerator in Figure 1 DETAILED DESCRIPTION OF THE INVENTION

[0008] The following embodiments will be described with reference to the drawings. The following embodiments are merely examples, and the scope of the invention is not limited thereto. The following embodiments can be implemented 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 modifications are within the scope of the invention as set forth in the claims and their equivalents.

[0009] In the following description, the left-right direction, front-rear direction, and up-down direction refer to the directions when viewing the refrigerator from the front, and the left-right direction corresponds to the width direction of the refrigerator. Furthermore, unless otherwise specified, the terms right, left, top, bottom, front, rear, back, spine, and near side refer to the position or side when viewing the refrigerator from the front, and for the refrigerator doors, refer to the position or side when viewing the refrigerator from the front with the doors closed.

[0010] (1) Configuration of household refrigerator 1 As shown in Fig. 1, a household refrigerator 1 according to this embodiment (hereinafter sometimes referred to as refrigerator 1) includes a refrigerator main body 2 made of an insulated box with an opening at the front. The refrigerator main body 2 is configured by providing an insulating material such as vacuum insulation or foam insulation in an insulating space formed between an outer box made of steel plate and an inner box made of synthetic resin. The refrigerator main body 2 has multiple storage spaces inside the inner box, and the storage spaces are divided into upper and lower sections by an insulating partition wall 3.

[0011] The space above the insulating partition wall 3 is a refrigerated space that is cooled to a refrigeration temperature range (for example, 1 to 5°C). The refrigerated space defined above the insulating partition wall 3 is further divided into upper and lower sections by a partition plate 4, with a refrigerating 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 provided with a plurality of storage shelves 5. The area below the lowest storage shelf 5 is a chilled compartment that is maintained at an especially low temperature within the refrigerator compartment 10. A hinged, pivotable refrigerator compartment door 15 is provided at the front opening of the refrigerator compartment 10. An operation display unit 6 is provided on the front of the refrigerator compartment door 15 to receive settings for the refrigerator 1 from the user and display the setting status of the refrigerator 1.

[0013] A refrigerator temperature sensor 60 for measuring the temperature inside the refrigerator compartment 10 is provided on the back surface of the refrigerator compartment 10. In addition, a door sensor 61 for detecting whether the refrigerator compartment door 15 is open or closed 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 drawer-type vegetable compartment door 16. A pair of left and right support frames that hold a storage container 20 are fixed to the inside of the vegetable compartment door 16, and the storage container 20 is configured to be pulled out to the outside when the door is opened. The specific configuration of the storage container 20 will be described in detail later.

[0015] The space below the insulating partition wall 3 is a freezing space that is cooled to a freezing temperature range (for example, -17°C or below). In the freezing space, an ice making compartment (not shown) equipped with an automatic ice maker and a first freezing compartment 13 are arranged side by side, and a second freezing compartment 14 is provided below them via a partition plate 7.

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

[0017] Behind the storage compartments in the refrigeration temperature range (refrigerator compartment 10 and vegetable compartment 12), there is defined a refrigerator cooler compartment 33 that houses a refrigerator cooler 30, a refrigerator blower 31, and a drain pan 32. The refrigerator cooler 30 cools the air in the refrigerator cooler compartment 33 to generate cold air, and the generated cold air is supplied to the refrigerator compartment 10 and vegetable compartment 11 via duct 34 by the refrigerator blower 31, thereby cooling the food stored in the vegetable compartment 10 and vegetable compartment 11. In other words, the refrigerator cooler 30 functions as a cooling unit that cools the food stored in the refrigerator compartment 10 and the food stored in the storage container 20 of the vegetable compartment 11.

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

[0019] At the back of the freezing temperature range storage compartments (ice making compartment, first freezer compartment 13, and second freezer compartment 14), a freezer cooler compartment 42 is defined, which houses a freezer cooler 38, a freezer blower 39, a defrost heater 40, and a drainage gutter 41. The freezer cooler 38 cools the air in the freezer cooler compartment 42 to generate cold air, which is then supplied by the freezer blower 39 through a duct 43 to the freezing temperature range ice making compartment, first freezer compartment 13, and second freezer compartment 14. Adjustable dampers may be provided at the outlets through which cold air is blown out to the ice making compartment and first freezer compartment 13, allowing the temperatures of the ice making compartment and first freezer compartment 13 to be controlled independently of second freezer compartment 14.

[0020] The refrigeration 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 to one of the refrigeration cooler 30 and the freezer cooler 38 by the switching valve 46. As a result, one of the refrigeration cooler 30 and the freezer cooler 38 to which the refrigerant is supplied is cooled to a predetermined temperature.

[0021] In addition, a control unit 45 consisting of a control board on which a microcomputer that controls the refrigerator 1 is mounted is provided on the outside of the refrigerator main body 2 (outside the refrigerator), for example, on the rear upper surface of the ceiling wall of the refrigerator main body 2.

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

[0023] Lower container 23 is box-shaped with a bottom that opens upward and is surrounded by a front wall, a rear wall, and left and right side walls, and has a deeper storage depth than upper container 50. The interior of lower container 23 is divided into front and rear by a front-rear partition wall 27 that extends in the width direction. This front-rear partition wall 27 is provided to connect the inner surfaces of the left and right side walls of lower container 23, and lower front container 23a is formed in front of front-rear partition wall 27, and lower rear container 23b is formed behind it.

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

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

[0026] The functional sheet 100 includes a moisture-permeable sheet and a breathable sheet, and is provided inside the sheet storage case 102. The moisture-permeable sheet is a waterproof and moisture-permeable sheet material, for example, a porous sheet material with numerous pores with diameters of 0.5 μm to 3 μm. It allows water vapor particles and oxygen molecules to pass through but blocks water particles larger than the pores. In addition, because it is porous, it also has a certain wind-blocking property that restricts the flow of air (wind). As an example, a moisture-permeable waterproof sheet made by laminating a polyester long-fiber nonwoven fabric and a polyethylene porous film can be used as the moisture-permeable sheet. The breathable sheet is made of a breathable sheet material, such as a nonwoven fabric sheet, a woven fabric, or a flexible porous resin sheet.

[0027] Upper container 50, located above lower container 23, is box-shaped with a bottom that opens upward and is surrounded by a front wall, a rear wall, and left and right side walls. Top opening 51 on the top surface of upper container 50 is an opening for putting stored items in and taking them out, and is closed by lid 80 in an openable and closable manner. The internal space of upper container 50 forms a fruit and vegetable storage compartment separated from vegetable compartment 11, and bottom surface 50a of upper container 50 serves as a storage area for placing food.

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

[0029] On the outside of the left and right side walls of the upper container 50, container upper legs 52 that rest on the inner box rails 25 and slide in the front-to-rear direction thereon, and container lower legs 53 that rest on the sliding surfaces 28 provided on the lower container 23 and slide in the front-to-rear direction thereon, protrude outward in the width direction. The container upper legs 52 and the container lower legs 53 support the upper container 50 so that it can move in the front-to-rear direction.

[0030] A downwardly protruding projection 55 is provided at the front end of the bottom wall of upper container 50. When vegetable compartment door 16 is opened and upper container 50 is pulled out to the front of vegetable compartment 12, and then vegetable compartment door 16 is closed, front and rear partition wall 27 of lower container 23 abuts against projection 55 of upper container 50, causing upper container 50 to move rearward.

[0031] As shown in FIG. 2, the lid 80 includes 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 forms the ceiling surface of the vegetable compartment 12.

[0032] The plate portion 81 is in the form of a generally flat plate that entirely covers and closes the top opening 51 of the upper container 50. The peripheral edge of the lower surface of the plate portion 81 forms a flat surface and is in surface contact with the entire peripheral edge of the top opening 51 of the upper container 50.

[0033] The support portions 84, 85 comprise a front support portion 84 located forward of the center position of the plate portion 81 in the fore-and-aft direction, and a rear support portion 85 located rearward of the front support portion 84, and are engaged with the partition plate 4 separating the refrigerator compartment 10 and the vegetable compartment 12, supporting the plate portion 81 so that it can move up and down within the vegetable compartment 12.

[0034] Heating unit 86 and temperature detection unit 87 are attached to plate unit 81. Heating unit 86 heats the food stored in upper container 50 from above, and temperature detection unit 87 detects the temperature of the food stored in upper container 50. Heating unit 86, together with refrigerated cooler 30, functions as a temperature adjustment means for adjusting the temperature of the food stored in upper container 50.

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

[0036] The lid 80 may be provided with a heat insulating material 88 that covers the heating unit 86 from the outside of the upper container 50 (from above the heating unit 86 in this embodiment). This makes it possible to prevent heat from the heating unit 86 from leaking outside the upper container 50.

[0037] In order to open the top opening 51 of such an upper container 50 when the vegetable compartment door 16 is closed as shown in Fig. 2, first open the vegetable compartment door 16. Because the upper container 50 is supported by the container upper legs 52 placed on the inner box rails 25, when the vegetable compartment door 16 is opened, the lower container 23 is pulled out to the outside, but the upper container 50 remains in the vegetable compartment 12 with the top opening 51 closed by the lid 80.

[0038] When upper container 50 stored in vegetable compartment 12 is pulled forward, upper container 50 is pulled out to the outside of the refrigerator. Because lid body 80 is supported by front support portion 84 and rear support portion 85 so that it can move up and down, when upper container 50 is pulled out to the outside of the refrigerator, the upper end of upper container 50 abuts against front positioning portion 82 provided on lid body 80, and upper container 50 moves forward while lifting the front end of lid body 80 upward.

[0039] Next, to store the upper container 50 that has been pulled out to the outside in the vegetable compartment 12, the vegetable compartment door 16 is closed. This causes the front and rear partition wall 27 of the lower container 23 to abut against the protrusion 55 of the upper container 50, moving the upper container 50 rearward. 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 top surface of the upper container 50. Thereafter, the upper container 50 slides along the underside of the lid 80 while moving rearward, causing the top opening 51 of the upper container 50 to be closed by the lid 80.

[0040] (3) Control of refrigerator 1 3, electrical components provided in the refrigerator main body 2, such as the operation and display unit 6, refrigeration blower 31, freezer blower 39, defrosting and heating unit 40, compressor 44, switching valve 46, refrigeration temperature sensor 60, door sensor 61, freezer temperature sensor 62, heating unit 86, and temperature detection unit 87, are electrically connected to control unit 45 provided on the top of refrigerator main body 2. When signals are input from various sensors or signals are input from a user communication terminal or the like that can communicate with operation and display unit 6 and refrigerator 1 by user operation, control unit 45 controls the overall operation of refrigerator 1 based on a control program pre-stored in memory.

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

[0042] In the refrigerator 1 of this embodiment, in principle, either the refrigeration cooling operation or the freezing cooling operation is performed at all times, but the refrigeration cooling operation or the freezing cooling operation may be stopped when a predetermined condition is met, such as when the second defrosting operation described below is being performed or when the temperatures of both the refrigerated space and the freezer space fall below a predetermined temperature.

[0043] (3-1) Refrigeration cooling operation When the refrigeration cooling start conditions are satisfied, the control unit 45 starts the refrigeration cooling operation by driving the compressor 44 at a predetermined frequency, opening the outlet on the refrigeration refrigerant flow path side of the switching valve 46 to allow the refrigerant to flow into the refrigeration cooler 30, and rotating the refrigeration blower 31. An example of the refrigeration cooling start conditions is when the temperature detected by the refrigeration temperature sensor 60 becomes equal to or higher than the ON temperature (e.g., 5°C) set for the refrigerated space.

[0044] In refrigeration cooling operation, cold air is generated by vaporizing a low-pressure, low-temperature refrigerant that flows into refrigeration cooler 30. The generated cold air circulates inside refrigeration compartment 10 and vegetable compartment 11 by the blowing action of refrigeration blower 31, and cools lower container 23 and upper container 50 provided in refrigeration compartment 10 and vegetable compartment 11 to a predetermined refrigeration temperature range.

[0045] Specifically, by the rotation of refrigeration blower 31, cold air generated in refrigeration cooler 30 is supplied to refrigeration compartment 10 from outlet 34a of duct 34, cooling refrigeration compartment 10. A portion of the cold air that flows through refrigeration compartment 10 flows into the return duct from an inlet provided at the rear of partition plate 4 and returns to refrigeration cooler compartment 33, while the remaining air flows into vegetable compartment 11 through communication passage 4a provided in partition plate 4. The cold air that flows into vegetable compartment 11 flows around lower container 23 and upper container 50, indirectly cooling the insides of lower container 23 and upper container 50, then returns to refrigeration cooler 30 from an inlet provided at the back of vegetable compartment 11 through the return duct, where it is cooled, and then sent back into refrigeration compartment 10 from outlet 34a.

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

[0047] Then, when the refrigeration cooling operation is completed, the control unit 45 drives the compressor 44 at a predetermined frequency while opening the outlet of the switching valve 46 on the refrigeration refrigerant flow path side to allow the refrigerant to flow into the refrigeration cooler 38, and further rotates the refrigeration blower 39 to start the refrigeration cooling operation.

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

[0049] The cold air circulated through the ice-making compartment, the first freezer compartment 13, and the second freezer compartment 14 passes through an intake port on the back of the second freezer compartment 14, passes through a return duct, and returns to the freezer cooler 38, where it is cooled, and then is blown back into the ice-making compartment, the first freezer compartment 13, and the second freezer compartment 14.

[0050] When a freeze-cooling termination condition is satisfied during the freeze-cooling operation, the control unit 45 terminates the freeze-cooling operation. For example, the freeze-cooling termination condition is satisfied when the temperature detected by the freeze-temperature sensor 62 reaches the OFF temperature (for example, −21° C.) set for the freezer space. There have been cases where this has happened.

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

[0052] (3-3) Defrosting operation In the refrigerator 1, while switching between the refrigeration / cooling operation and the freezing / cooling operation, if a predetermined defrosting start condition is satisfied, the refrigerator 1 executes the first defrosting operation and the second defrosting operation.

[0053] The first defrosting operation is an operation for melting and removing frost adhering to the refrigerated cooler 30, and supplying the moisture of the melted frost to the refrigerated space to humidify the refrigerated space. Specifically, the control unit 45 closes the outlet of the switching valve 46 on the refrigerated refrigerant flow path side and stops the compressor 44, thereby stopping the supply of refrigerant to the refrigerated cooler 30 and driving the refrigerated blower 31.

[0054] As a result of these controls, the air in the refrigerated space exchanges heat with the frosted refrigerated cooler 30, and then is returned to the refrigerator compartment 10 and the vegetable compartment 11. This raises the temperature of the refrigerated cooler 30 to melt the frost that has adhered to the refrigerated cooler 30, and the moisture in the melted frost is vaporized and sent to the refrigerator compartment 10 and the vegetable compartment 11, so that humidified air having a higher relative humidity than the cold air sent to the refrigerator compartment 10 and the vegetable compartment 11 during the above-mentioned refrigerated cooling operation is supplied to the refrigerator compartment 10 and the vegetable compartment 11, thereby humidifying the refrigerator compartment 10 and the vegetable compartment 11.

[0055] The second defrosting operation is an operation for melting and removing frost adhering to the freeze-cooler 38. Specifically, the control unit 45 closes the outlet on the refrigeration refrigerant flow path side of the switching valve 46 and stops the compressor 44, thereby stopping the supply of refrigerant to the freeze-cooler 38, stopping the freeze-cooler blower 39, and energizing the defrost heating unit 40. Through these controls, the freeze-cooler 38 is heated by the heat from the defrost heating unit 40, and the frost adhering to the freeze-cooler 38 melts. The defrost water generated when the frost melts is received by the drain gutter 41 and discharged into the evaporation tray 37 provided in the machine room 36.

[0056] (3-4) Fruit and vegetable preservation operation The refrigerator 1 executes a fruit and vegetable preservation operation in which a cooling preservation operation and a recovery operation are alternately performed in the upper container 50 that constitutes the fruit and vegetable storage compartment. The fruit and vegetable preservation operation may be executed when a predetermined start condition is met, such as when the user issues a command to execute the fruit and vegetable preservation operation by performing a predetermined operation on the operation display unit 6 or a user communication terminal, or when the control unit 45 detects that food has been stored in the upper container 50. Alternatively, the fruit and vegetable preservation operation may be executed constantly while the refrigerator 1 is powered on.

[0057] The refrigerated storage operation is an operation for cooling food stored in upper container 50. When performing the refrigerated storage operation, control unit 45 drives heating unit 86 as needed while indirectly cooling the inside of upper container 50 with cold air supplied to vegetable compartment 11 so that the temperature of the food detected by temperature detection unit 87 becomes first temperature Te1.

[0058] The control unit 45 continues to perform the cooling storage operation for the first time Ti1, thereby cooling the food stored in the upper container 50 at the first temperature Te1 for the first time Ti1, and then ends the cooling storage operation and starts the recovery operation.

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

[0060] By continuing the recovery operation for the second time Ti2, control unit 45 maintains the food stored in upper container 50 at second temperature Te2 for the second time Ti2, and then ends the recovery operation and starts refrigerated storage operation. Thereafter, refrigerated storage operation for the first time Ti1 and recovery operation for the second time Ti2 are alternately performed.

[0061] If an end condition is met during the fruit and vegetable preservation operation, the control unit 45 ends the fruit and vegetable preservation operation. Examples of the end condition include when the user performs a predetermined operation on the operation display unit 6 or the user communication terminal to instruct the end of the fruit and vegetable preservation operation, or when the control unit 45 detects that food has been removed from the upper container 50.

[0062] Note that even during the refrigeration preservation operation and the recovery operation, the control unit 45 alternately switches between the refrigeration cooling operation and the freezing cooling operation. Therefore, even during the refrigeration preservation operation or the recovery operation, while the refrigeration cooling operation is being performed, the cold air generated by the refrigeration cooler 30 is supplied to the vegetable compartment 11 via the refrigerator compartment 10, thereby indirectly cooling the inside of the upper container 50.

[0063] The first temperature Te1 set in the refrigerated storage operation can be set to a temperature equal to or higher than the freezing temperature Tf (e.g., Tf = 0°C) of the food stored in the upper container 50 and equal to or lower than the critical temperature Tc of the food. The second temperature Te2 set in the recovery operation can be set to a temperature 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: mannitol solutions at different temperatures in 1°C increments between 1°C and 20°C are prepared, and food tissue is immersed in the solutions at each temperature for 30 minutes. The amount of ions leaking from the food tissue into the solution is measured using an electrical conductivity meter to determine the electrolyte leakage rate at each temperature. An Arrhenius plot of the electrolyte leakage rate is then created from the electrolyte leakage rate at each temperature, and the inflection point on the plot can be determined as the critical temperature Tc of the food.

[0065] It is assumed that various foods with different critical temperatures Tc will be stored in the household refrigerator 1. Therefore, the critical temperature Tc may be set to a temperature selected from the range of 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 uppermost shelf 5 of the refrigerator compartment 10 when the cooling strength of the refrigerator compartment 10 is set to the lowest, or may be set to a temperature higher than the lowest temperature reached by the upper front end of the vegetable compartment 11 when the cooling strength of the refrigerator compartment 10 is set to the lowest, or may be set to a temperature higher than the ON temperature set as the refrigeration cooling start condition.

[0066] Furthermore, when the critical temperature Tc is selected from the range of 2 to 15°C, the temperature selected by the user may be set as the critical temperature Tc. Alternatively, a correspondence table between foods and critical temperatures Tc may be stored in advance in the refrigerator 1 or in a storage 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 on the operation display unit 6 or the user communication terminal may be read from the correspondence table and set as the critical temperature Tc.

[0067] The first temperature Te1 and the second temperature Te2 are preferably set so 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 to 5°C, and the second temperature Te2 can be set to 11 to 14°C.

[0068] The time (second time) Ti2 for performing the recovery operation is preferably the same as or longer than the time (first time) Ti1 for performing the cooled storage operation, and the time for continuously performing the cooled storage operation is preferably 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 repeating cycle of the cooling storage operation and the recovery operation, i.e., the combined time (Ti1+Ti2) of the time Ti1 for performing one cooling storage operation and the time Ti2 for performing one recovery operation, is longer than the repeating cycle of the refrigeration cooling operation and the freezing cooling operation, i.e., the total time for performing one refrigeration cooling operation and one freezing cooling operation.

[0070] (4) Effects The refrigerator 1 of this embodiment performs a cooling preservation 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 preservation operation to recover low-temperature damage that has occurred in food stored in the upper container 50.This makes it possible to prevent low-temperature damage to food and to prevent a decrease in freshness, and to store food while maintaining its quality.

[0071] In this embodiment, 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 storage operation and the critical temperature Tc, so that the inside of the refrigerator 1 is not unnecessarily heated and low-temperature damage can be suppressed.

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

[0073] (5) Example of change In the above embodiment, a case where fruit and vegetable preservation operation is performed in the upper container 50 is described, but a heating unit may be provided in the chilled compartment or the first freezer compartment 13 provided in the refrigerator compartment 10, and fruit and vegetable preservation operation may be performed in the chilled compartment or the first freezer compartment 13. [Explanation of symbols]

[0074] REFRIGERATOR SYMBOLS 1...refrigerator, 2...refrigerator body, 3...insulating partition wall, 4...partition plate, 5...mounting shelf, 10...refrigerating compartment, 11...vegetable compartment, 13...first freezer compartment, 14...second freezer compartment, 20...storage container, 23...lower container, 30...refrigerated cooler, 31...refrigerated blower, 33...refrigerated cooler compartment, 38...freezer cooler, 39...freezer blower, 44...compressor, 45...control unit, 50...upper container, 80...lid, 81...plate portion, 82...front support portion, 86...heating portion, 87...temperature detection portion

Claims

1. a storage compartment, a temperature adjusting means for adjusting the temperature of food stored in the storage compartment, and a control unit for controlling the temperature adjusting means; In a household refrigerator, the control unit executes a cooled storage operation in which the food is cooled to a first temperature, and a recovery operation in which the food is heated to a second temperature higher than the first temperature to recover from low-temperature damage caused to the food, the first temperature is equal to or higher than the freezing temperature of the food product and equal to or lower than a critical temperature, and the second temperature is higher than the critical temperature; a temperature difference between the second temperature and the critical temperature is smaller than a temperature difference between the first temperature and the critical temperature; The household refrigerator alternately repeats the cooling preservation operation and the recovery operation at a temperature of 0°C or higher.

2. A household refrigerator as described in claim 1, wherein the critical temperature is changeable.

3. A household refrigerator as described in claim 2, wherein the critical temperature can be changed according to user selection.

4. The household refrigerator according to any one of claims 1 to 3, wherein an execution time of the recovery operation is longer than an execution time of the cooling storage operation.

5. The household refrigerator according to any one of claims 1 to 3, wherein an execution time of the recovery operation is equal to an execution time of the cooling storage operation.

6. The household refrigerator according to any one of claims 1 to 5, wherein the cooling and preserving operation is continuously performed for 24 hours or less.

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