JP7473390B2 - refrigerator - Google Patents

Description

The present invention relates to a refrigerator.

Patent Document 1 describes that by performing off-cycle operation (first operation), for example, the following effects can be obtained: "The heat load increases due to frost and melted water from the frost, and the porous frost containing a lot of air changes to frost closer to ice with less air, resulting in operation in a state where the heat transfer performance of the cooler is good."

JP 2011-38716 A

However, in the refrigerator described in Patent Document 1, the compressor needs to be stopped in order to perform off-cycle operation. To secure the time to stop the compressor, it is necessary to increase the amount of cooling while the compressor is operating. Increasing the rotation speed of the compressor is an effective way to increase the amount of cooling, but this lowers the evaporation temperature of the refrigerant during cooling. When the evaporation temperature drops, the cooling efficiency (amount of cooling relative to the amount of power consumed) generally decreases, leading to a decrease in energy-saving performance.

The present invention aims to solve the above-mentioned problems of the conventional refrigerator, and aims to provide a refrigerator that performs off-cycle operation while driving the compressor, thereby further improving cooling efficiency.

The refrigerator of the present invention includes a first refrigerant flow path through which a refrigerant flows in the order of a compressor, a heat radiating section, a refrigerant control means, a first pressure reducing section, and a first evaporator; a second refrigerant flow path through which a refrigerant flows in the order of the compressor, the heat radiating section, the refrigerant control means, a second pressure reducing section, and a second evaporator; a first fan that blows air cooled by the first evaporator; a plurality of first evaporator cooling chambers to which air is blown by the first fan; a second fan that blows air cooled by the second evaporator; and one or more second evaporator cooling chambers to which air is blown by the second fan, wherein the plurality of first evaporator cooling chambers each include one or more freezer storage chambers set in a freezing temperature zone and one or more refrigerated storage chambers set in a refrigeration temperature zone, and a control unit that executes an operation of driving the first fan to blow air to the refrigerated storage chamber while suppressing air blowing from the first fan to all of the freezer storage chambers, and driving the second fan while flowing a refrigerant in the second refrigerant flow path to cool the second evaporator cooling chamber .

The present invention provides a refrigerator that performs off-cycle operation while driving the compressor, further improving cooling efficiency.

FIG. 1 is a front view showing a refrigerator according to a first embodiment. 2 is a cross-sectional view taken along line II-II of FIG. 1. FIG. 2 is a schematic diagram showing an air passage configuration of the refrigerator according to the first embodiment. 1 is a configuration diagram showing a refrigeration cycle of a refrigerator according to a first embodiment. FIG. 5 is a flowchart showing cooling operation control of the refrigerator according to the first embodiment. 5 is a flowchart showing a vegetable compartment cooling control of the refrigerator according to the first embodiment. 5 is a flowchart showing an R off cycle operation control of the refrigerator according to the first embodiment. 4 is a time chart showing cooling operation control of the refrigerator according to the first embodiment. 5 is a flowchart showing F defrosting operation control of the refrigerator according to the first embodiment. 5 is a flowchart showing an R defrosting operation control of the refrigerator according to the first embodiment. 4 is a time chart showing a defrosting operation control of the refrigerator according to the first embodiment. FIG. 7 is a cross-sectional view of a refrigerator according to a second embodiment. FIG. 11 is a front view showing an air passage configuration of a refrigerator according to a second embodiment. FIG. 11 is a rear view of the interior of the refrigerator according to the second embodiment. FIG. 11 is a schematic diagram showing an air passage configuration of a refrigerator according to a second embodiment. FIG. 11 is an explanatory diagram showing an example of operating conditions of various members according to the second embodiment.

The following describes a form for implementing the present invention (the present embodiment). However, the present embodiment is not limited to the following content in any way, and can be modified as desired within the scope of the gist of the present invention.

First Embodiment
Fig. 1 is a front view showing a refrigerator according to a first embodiment. In the following description, a six-door refrigerator 1 will be taken as an example, but the refrigerator is not limited to a six-door refrigerator.
As shown in Fig. 1, the insulated box 10 of the refrigerator 1 has storage compartments arranged in the following order from the top: a refrigerator compartment 2, an ice-making compartment 3, an upper freezer compartment 4, a lower freezer compartment 5, and a vegetable compartment 6, which are arranged on the left and right sides. The ice-making compartment 3, the upper freezer compartment 4, and the lower freezer compartment 5 are collectively referred to as a freezer compartment 7. The refrigerator 1 has doors that open and close the openings of each storage compartment. These doors are rotating refrigerator compartment doors 2a and 2b divided into left and right doors that open and close the opening of the refrigerator compartment 2, and a pull-out ice-making compartment door 3a, an upper freezer compartment door 4a, a lower freezer compartment door 5a, and a vegetable compartment door 6a that open and close the openings of the ice-making compartment 3, the upper freezer compartment 4, the lower freezer compartment 5, and the vegetable compartment 6, respectively.

The refrigerator compartment door 2a is provided with an operation unit 19 that shows typical interior settings and states. Door hinges (not shown) are provided at the top and bottom of the refrigerator compartment 2 to secure the refrigerator compartment doors 2a and 2b to the refrigerator 1.

The refrigerator compartment 2 is a refrigerated storage compartment whose interior is kept in the refrigeration temperature range (0°C or higher), for example at an average of about 4°C. The freezer compartment 7 is a refrigerated storage compartment whose interior is kept in the freezing temperature range (less than 0°C), for example at an average of about -18°C. The vegetable compartment 6 is a refrigerated storage compartment whose interior is in the refrigeration temperature range, for example at an average of about 6°C, and uses indirect cooling, described below, to prevent food from drying out.

FIG. 2 is a cross-sectional view taken along line II-II of FIG.
As shown in FIG. 2, the refrigerator 1 is configured such that the outside and the inside of the refrigerator are separated by an insulated box 10 formed by filling a space between an outer box 10a (made of steel plate) and an inner box 10b (made of synthetic resin) with a foam insulation material (e.g., urethane foam). In addition to the foam insulation material, the insulated box 10 also has a vacuum insulation material 25, which has a lower thermal conductivity than the foam insulation material, mounted between the outer box 10a and the inner box 10b, thereby improving the insulation performance without reducing the food storage volume. Here, the vacuum insulation material is formed by wrapping a core material such as glass wool or urethane with an outer packaging material. The outer packaging material includes a metal layer (e.g., aluminum) to ensure gas barrier properties. In addition, the vacuum insulation material 25 is also provided in the lower freezer door 5a of the lower freezer 5, which is a relatively large freezer storage compartment.

The refrigerator compartment 2 is separated from the ice-making compartment 3 and the upper freezer compartment 4 by a heat-insulating partition wall 28. The lower freezer compartment 5 and the vegetable compartment 6 are separated by a heat-insulating partition wall 29. The ice-making compartment 3, the upper freezer compartment 4, and the lower freezer compartment 5 have heat-insulating partition walls 30 on the front side of each storage compartment to prevent air in the freezer compartment 7 from leaking out of the compartment through the gaps in the doors 3a, 4a, and 5a, and to prevent air from the outside from entering each storage compartment. The freezer compartment 7 and the vegetable compartment 6 are each provided with an ice-making compartment container (not shown), an upper freezer compartment container 4b, a lower freezer compartment container 5b, and a vegetable compartment container 6b, which are pulled out together with the doors 3a, 4a, 5a, and 6a, respectively.

The refrigerator 1 is equipped with a first evaporator 14a, which is a freezer-compatible evaporator for cooling the freezer compartment 7 and the vegetable compartment 6. The first evaporator 14a is provided in the first evaporator compartment 8a, which is a freezer evaporator compartment provided at the rear of the freezer compartment 7. The freezer compartment 7 and the first evaporator compartment 8a are separated by a partition member 20a that constitutes the wall surface on the freezer compartment 7 side and a partition member 20b that constitutes the first evaporator compartment 8a side. The partition member 20a is made of polypropylene, which is a type of resin material, and has a thickness of 1.5 mm. The partition member 20b (foamed insulation material) is made of foamed polystyrene foam (expanded polystyrene). The thickness of the partition member 20b is set to 10 mm in consideration of the moldability during foaming, the ease of assembly when installing the refrigerator, impact resistance, and the suppression of temperature fluctuations in the freezer compartment 7.

FIG. 3 is a schematic diagram showing an air passage configuration of the refrigerator according to the first embodiment.
As shown in Fig. 3, when cooling the freezer compartment 7, the freezer compartment damper 101 is opened and the first fan 9a, which is a freezer fan, is driven. The air in the first evaporator chamber 8a, which has been cooled by the first evaporator 14a, is blown into the freezer compartment 7 through the freezer compartment damper 101, the freezer compartment air duct 12, and the freezer compartment discharge port 12a by the first fan 9a provided above the first evaporator 14a, thereby cooling the inside of the freezer compartment 7. The air blown into the freezer compartment 7 returns to the first evaporator chamber 8a from the freezer compartment return port 12b, and is cooled again by the first evaporator 14a.

When cooling the vegetable compartment 6, the vegetable compartment damper 102 is opened and the first fan 9a is driven. The air in the first evaporator chamber 8a, which has been cooled by the first evaporator 14a, is blown into the vegetable compartment 6 by the first fan 9a through the vegetable compartment damper 102, cooling the vegetable compartment 6. When the vegetable compartment 6 is at a low temperature, the vegetable compartment damper 102 is closed to prevent the vegetable compartment 6 from being cooled. The air blown into the vegetable compartment 6 returns to the bottom of the first evaporator chamber 8a from the cold air return section 18 on the vegetable compartment side, which is provided at the bottom of the insulating partition wall 29 (see Figure 2).

A defrost heater 21 (see FIG. 2) for heating the first evaporator 14a is provided at the bottom of the first evaporator chamber 8a. The defrost heater 21 is, for example, a 50W to 200W electric heater, and in this embodiment is a 150W radiant heater. The defrost water (melt water) generated when the first evaporator 14a is defrosted falls into a first evaporator drain 23a (see FIG. 2) provided at the bottom of the first evaporator chamber 8a, and is discharged into an evaporation dish 32 (see FIG. 2) provided at the top of the compressor 24 (see FIG. 2) via a first evaporator drain outlet 22a (see FIG. 2) and a first evaporator drain pipe 27a (see FIG. 2).

The second evaporator 14b, which is an evaporator for the refrigeration storage compartment, is provided in the second evaporator compartment 8b, which is an evaporator compartment for refrigeration provided at approximately the rear of the refrigeration compartment 2. The air that has been cooled by heat exchange with the second evaporator 14b is sent to the refrigeration compartment 2 through the refrigeration compartment air duct 11 and the refrigeration compartment outlet 11a by the second fan 9b, which is a refrigeration fan provided above the second evaporator 14b, and cools the inside of the refrigeration compartment 2. The air sent to the refrigeration compartment 2 returns to the second evaporator compartment 8b from the refrigeration compartment return port 15 and is cooled again by the second evaporator 14b.

The second evaporator 14b circulates the air in the refrigerator compartment 2 and performs defrosting by off-cycle defrosting, which uses the heat from the refrigerator compartment 2. The defrost water generated during defrosting of the second evaporator 14b falls into the second evaporator drain 23b (see Figure 2) provided at the bottom of the second evaporator chamber 8b, and is discharged into the evaporation tray 32 (see Figure 2) provided in the machine chamber 39 (see Figure 2) via the second evaporator drain outlet (not shown) and the second evaporator drain pipe (not shown).

The refrigerator compartment 2, freezer compartment 7, and vegetable compartment 6 are provided with a refrigerator compartment temperature sensor 41, a freezer compartment temperature sensor 42, and a vegetable compartment temperature sensor 43 on the rear side of the interior of the refrigerator compartment 2, the freezer compartment 7, and the vegetable compartment 6, respectively. A first evaporator temperature sensor 40a is provided on the top of the first evaporator 14a. A second evaporator temperature sensor 40b is provided on the top of the second evaporator 14b. These temperature sensors 41, 42, 43, 40a, and 40b detect the temperatures of the refrigerator compartment 2, the freezer compartment 7, the vegetable compartment 6, the second evaporator 14b, and the first evaporator 14a. In addition, an outside air temperature sensor 37 that detects the temperature of the outside air (outside the refrigerator compartment air) and an outside air humidity sensor 38 that detects the humidity are provided inside the door hinge cover 16 on the ceiling of the refrigerator 1. Other sensors, such as door sensors (not shown) that detect the open/closed states of the doors 2a, 2b, 3a, 4a, 5a, and 6a, are also provided.

At the top of the refrigerator 1, there is disposed a control board (control device, control section) 31 (see FIG. 2) equipped with a CPU, which is part of the control device, memories such as ROM and RAM, an interface circuit, etc. The control board 31 is connected by electrical wiring (not shown) to an outside air temperature sensor 37, an outside air humidity sensor 38, a refrigerator compartment temperature sensor 41, a freezer compartment temperature sensor 42, a vegetable compartment temperature sensor 43, a first evaporator temperature sensor 40a, a second evaporator temperature sensor 40b, etc.

The control board 31 also controls the compressor 24, the first fan 9a, the second fan 9b, the freezer damper 101, and the vegetable compartment damper 102 (see FIG. 3), which will be described later, based on the output values of each sensor, the settings of the operation unit 18, and programs pre-recorded in the ROM.

In addition, the refrigerator 1 of this embodiment is provided with a communication board (not shown) that can connect to external devices. By providing this communication board, information about the refrigerator 1 can be provided to mobile devices such as smartphones and personal computers, and settings such as modes can be changed by operating these devices in the same way as with the operation unit 26 (see FIG. 2).

FIG. 4 is a configuration diagram showing the refrigeration cycle of the refrigerator according to the first embodiment.
As shown in FIG. 4 , the refrigerator 1 includes the compressor 24, an external radiator 50a and a wall surface heat radiation piping 50b which are heat radiation means for radiating heat from the refrigerant, a condensation prevention piping 50c which suppresses condensation on the front portions of the partition walls 28, 29, and 30 (see FIG. 2 ), a freezing capillary tube 53a and a refrigerating capillary tube 53b which are pressure reducing means for reducing the pressure of the refrigerant, and a first evaporator 14a and a second evaporator 14b which exchange heat between the refrigerant and the air inside the refrigerator and absorb heat inside the refrigerator.

The refrigerator 1 also has a first refrigerant flow path R1 through which the refrigerant flows in the order of the compressor 24, the external radiator 50a, the wall surface heat radiation pipe 50b, the condensation prevention pipe 50c, the refrigeration capillary tube 53a, and the first evaporator 14a. The refrigerator 1 also has a second refrigerant flow path R2 through which the refrigerant flows in the order of the compressor 24, the external radiator 50a, the wall surface heat radiation pipe 50b, the condensation prevention pipe 50c, the refrigeration capillary tube 53b, and the second evaporator 14b.

The refrigerator 1 also includes a dryer 51 that removes moisture in the refrigeration cycle, gas-liquid separators 54a and 54b that prevent liquid refrigerant from flowing into the compressor 24, a three-way valve 52 that controls the refrigerant flow path, a check valve 56, and a refrigerant junction 55 that connects the refrigerant flows. The refrigeration cycle is formed by connecting these components with refrigerant piping.

The refrigerator 1 uses 80 g of isobutane, a flammable refrigerant, as a refrigerant. The compressor 24 is equipped with an inverter to change the rotation speed. The three-way valve 52 is a component that has two outlets 52a and 52b, and is capable of switching between a refrigeration operation in which the refrigerant flows through the outlet 52b side and a freezing operation in which the refrigerant flows through the outlet 52a side. The three-way valve 52 is also capable of switching between a fully closed mode in which the refrigerant does not flow through either the outlet 52b or the outlet 52a, and a fully open mode in which the refrigerant can flow through both outlets.

The refrigerant in the refrigerator 1 flows as follows. That is, the refrigerant discharged from the compressor 24 flows through the external radiator 50a, the wall surface heat radiation pipe 50b, the condensation prevention pipe 50c, the dryer 51, and then reaches the three-way valve 52. The outlet 52a of the three-way valve 52 is connected to the freezing capillary tube 53a via the refrigerant pipe. The outlet 52b of the three-way valve 52 is connected to the refrigeration capillary tube 53b via the refrigerant pipe.

When the three-way valve 52 is set to allow the refrigerant to flow to the outlet 52a, the refrigerant flowing out of the outlet 52a flows through the freezing capillary tube 53a, the first evaporator 14a, the gas-liquid separator 54a, the check valve 56, and the refrigerant junction 55 in this order, and then returns to the compressor 24. The check valve 56 is arranged so that the refrigerant flows from the gas-liquid separator 54a to the refrigerant junction 55 side, but does not flow from the refrigerant junction 55 to the gas-liquid separator 54b side. The refrigerant that has become low-pressure and low-temperature in the freezing capillary tube 53a flows through the first evaporator 14a, causing the first evaporator 14a to become low-temperature, thereby cooling the air in the first evaporator chamber 8a (see FIG. 2). This air is blown into the freezer chamber 7 and the vegetable chamber 6, thereby cooling the freezer chamber 7 and the vegetable chamber 6.

When the three-way valve 52 is set so that the refrigerant flows to the outlet 52b side, the refrigerant flowing out from the outlet 52b flows through the refrigeration capillary tube 53b, the second evaporator 14b, the gas-liquid separator 54b, and the refrigerant junction 55 in that order, before returning to the compressor 24. The refrigerant that has become low-pressure and low-temperature in the refrigeration capillary tube 53b flows through the second evaporator 14b, which then becomes low-temperature, and the air in the second evaporator chamber 8b (see Figure 2) can be cooled. This air is blown into the refrigerator compartment 2, thereby cooling the refrigerator compartment 2.

5A to 5C are flowcharts showing cooling operation control of the refrigerator according to the first embodiment.
As shown in FIG. 5A, in step S1, when the freezing operation is completed, the control device (control board 31) turns off (stops) the first fan 9a and closes the freezing compartment damper 101.

Then, the process proceeds to the processing of the refrigeration operation implementation conditions shown in steps S3 to S5. That is, in step S3, the control device determines whether or not the R off cycle operation has ended. Details of the R off cycle operation (see FIG. 5C) will be described later. If the control device determines that the R off cycle operation (refrigeration off cycle operation) has ended (S3, Yes), it proceeds to step S4, and if the control device determines that the R off cycle operation has not ended (S3, No), it proceeds to step S8.

In step S4, the control device determines whether the R defrosting operation (refrigerator compartment defrosting operation) has ended. Details of the R defrosting operation (see FIG. 7B) will be described later. If the control device determines that the R defrosting operation has ended (S4, Yes), it proceeds to step S5, and if the control device determines that the R defrosting operation has not ended (S4, No), it proceeds to step S8.

In step S5, the control device determines whether the refrigerator compartment temperature _TR is equal to or higher than the temperature _{TR_start} at which the refrigeration operation starts. The refrigerator compartment temperature _TR is the temperature detected by the refrigerator compartment temperature sensor 41. The refrigerator compartment temperature _{TR_start} is set appropriately, for example, to 6°C or higher. If the control device determines that the refrigerator compartment temperature _TR is equal to or higher than the temperature _{TR_start} (S5, Yes), the control device proceeds to step S6, and if the control device determines that the refrigerator compartment temperature _TR is not equal to or higher than the temperature _{TR_start} (S5, No), the control device proceeds to step S8.

In step S6, the control device starts the refrigeration operation. That is, the control device switches the three-way valve 52 to the outlet 52b side, turns on the compressor 24, turns on the second fan 9b, and resets the timer _tR .

In step S7, the control device determines whether or not to end the refrigeration operation. The determination of whether or not to end the refrigeration operation is made, for example, based on whether or not the refrigerator compartment temperature _TR has dropped to a refrigeration operation stop temperature _TROFF or lower. If the control device does not end the refrigeration operation (S7, No), it repeats the process of step S7, and if the control device ends the refrigeration operation (S7, Yes), it proceeds to step S8.

In step S8, the control device determines whether or not a freezing operation execution condition is satisfied. The freezing operation execution condition is, for example, that the freezing compartment temperature _TF falls to a freezing operation stop temperature _TFOFF or lower. If the freezing operation execution condition is satisfied (S8, Yes), the control device proceeds to step S9, and if the freezing operation execution condition is not satisfied (S8, No), the control device proceeds to step S17.

In step S9, the control device performs a pre-freezing operation, that is, the control device switches the three-way valve 52 to the outlet port 52a side, switches the compressor 24 ON (H: high speed), and resets the timer _tF .

In step S10, the control device determines whether or not the timer _tF has elapsed a first predetermined time or more. The first predetermined time is determined by a prior test and is set to, for example, 2 minutes (min). If the control device determines that the timer _tF has elapsed a first predetermined time or more (S10, Yes), the control device proceeds to step S11, and if the control device determines that the timer _tF has not elapsed a first predetermined time or more (S10, No), the control device repeats the process of step S10.

In step S11, the control device performs freezing operation. That is, the control device turns on the first fan 9a and opens the freezer damper 101.

In step S12, the control device determines whether the vegetable compartment 6 is being cooled. Whether the vegetable compartment 6 is being cooled is determined, for example, by whether the vegetable compartment damper 102 is open. If the control device determines that the vegetable compartment 6 is being cooled (S12, Yes), the process proceeds to step S14. If the control device determines that the vegetable compartment 6 is not being cooled (S12, No), the process proceeds to step S13.

In step S13, the control device turns the compressor 24 ON (H→M: from high speed to medium speed).

In step S14, the control device determines whether or not a freezing operation end condition is satisfied. The freezing operation end condition is determined based on whether or not the freezing compartment temperature _TF detected by the freezing compartment temperature sensor 41 has dropped to a predetermined temperature _TFoff . If the freezing operation end condition is satisfied (S14, Yes), the control device proceeds to step S15, and if the freezing operation end condition is not satisfied (S14, No), the control device returns to step S12.

In step S15, the control device performs a refrigerant recovery operation, that is, the control device fully closes the three-way valve 52, turns on the compressor 24, and resets the timer _tF .

In step S16, the control device judges whether or not the timer _tF has elapsed a second predetermined time or more. The second predetermined time is determined by a prior test and is set to, for example, 2 minutes (min). If the control device judges that the timer _tF has elapsed the second predetermined time (S16, Yes), it returns to step S1, and if it judges that the timer tF has not elapsed the second predetermined time or more (S16, No), it repeats the process of step S16.

If the freezing operation conditions are not met (S8, No), in step S17, the control device fully closes the three-way valve 52 and turns off (stops) the compressor 24, and returns to step S2. Note that if the compressor 24 is OFF, the process proceeds from step S2 to the processing of the refrigeration operation conditions (S3 to S5).

In parallel with the process proceeding from step S1 to steps S3 to S5, the vegetable compartment cooling control shown in FIG. 5B (including F-off cycle operation) is carried out.

As shown in FIG. 5B, in step S101, the control device resets a timer _tR .

In step S102, the control device determines whether a third predetermined time ( _tR ) has elapsed since the timer started. The third predetermined time is determined by a prior test and is set to, for example, 10 minutes (min). If the control device determines that the third predetermined time has elapsed (S102, Yes), the control device proceeds to step S103, and if the control device determines that the third predetermined time has not elapsed (S102, No), the control device repeats the process of step S102.

In step S103, the control device turns on the first fan 9a and opens the vegetable compartment damper 102.

In step S104, the control device determines whether or not the crisper temperature T _V detected by the crisper temperature sensor 43 is equal to or lower than the predetermined temperature T _Voff . If the control device determines that the crisper temperature T _V is equal to or lower than the predetermined temperature T _Voff (S104, Yes), the control device proceeds to step S105, and if the control device determines that the crisper temperature T V is not equal to or lower than the predetermined temperature T _Voff (S104, No), the control device repeats the process of step S104.

In step S105, the control device determines whether or not the freezing operation is in progress. Whether or not the freezing operation is in progress is determined by whether the first fan 9a is ON and the freezer compartment damper 101 is open. If the control device determines that the freezing operation is in progress (S105, Yes), the process proceeds to step S106, and if the control device determines that the freezing operation is not in progress (S105, No), the process proceeds to step S107.

In step S106, the control device closes the vegetable compartment damper 102 and ends the process.

In step S107, the control device closes the vegetable compartment damper 102 and turns off the first fan 9a, ending the process.

On the other hand, if it is determined in step S7 that the refrigeration operation has ended (S7, Yes), the R-off cycle operation (S201 to S203) shown in FIG. 5C is carried out in parallel with step S8.

As shown in FIG. 5C, in step S201, the control device turns on the second fan 9b.

In step S202, the control device determines whether the second evaporator temperature _TDR of the second evaporator 14b (refrigerator-side evaporator) is equal to or higher than a predetermined temperature _TDRoff . The second evaporator temperature _TDR is detected by the second evaporator temperature sensor 40b. The predetermined temperature _TDRoff is a second evaporator stop condition for stopping the second evaporator 14b. If the control device determines that the second evaporator temperature _TDR is equal to or higher than the predetermined temperature _TDRoff (S202, Yes), the control device proceeds to step S203, and if the control device determines that the second evaporator temperature _TDR is not equal to or higher than the predetermined temperature _TDRoff (S202, No), the control device repeats the process of step S202.

In step S203, the control device turns off the second fan 9b and ends the process.

Fig. 6 is a time chart showing cooling operation control of the refrigerator according to the first embodiment. In Fig. 6, the temperature T _V of the vegetable compartment 6, the temperature T _R of the refrigerator compartment 2, and the temperature T _F of the freezer compartment 7 are shown by solid lines. In Fig. 6, the temperature T _DR of the second evaporator 14b and the temperature T _DF of the first evaporator 14a are shown by dashed lines.

As shown in FIG. 6, time t ₀ is the time when the refrigeration operation for cooling the refrigerator compartment 2 is started. In this embodiment, at time t ₀ , the freezing operation (F operation) is ended (step S1), a determination is made as to whether or not the refrigerator operation is to be performed (steps S3 to S5), and the refrigeration operation (R operation) shown in step S6 is started. In the R operation, the three-way valve 52 is switched from fully closed to the outlet 52b side, the compressor 24 is continuously driven (medium speed M → low speed L), and the second fan 9b is operated (OFF → ON). As a result, the refrigerant flows into the second evaporator 14b, and the second evaporator 14b becomes low temperature. In addition, the air that has passed through the second evaporator 14b and has become low temperature is blown into the refrigerator compartment 2, thereby cooling the refrigerator compartment 2. Here, the temperature T _DR of the second evaporator 14b during the refrigeration operation is set higher than that of the first evaporator 14a during the freezing operation described later. In general, the higher the temperature of the evaporator, the higher the COP (the ratio of the amount of heat to be cooled to the input of the compressor 24) and the higher the energy saving performance. When cooling the freezer compartment 7, the evaporator temperature needs to be low, but since the second evaporator 14b cools only the storage compartment in the refrigeration temperature range that can be cooled even with a high evaporator temperature, the evaporator temperature is raised to improve energy saving performance when cooling the refrigerator compartment 2. In the refrigerator 1 of this embodiment, the rotation speed of the compressor 24 during refrigeration operation is set to a lower speed (L) than during freezing operation so that the temperature _TDR of the second evaporator 14b during refrigeration operation is high.

Here, in the refrigerator 1 of this embodiment, during the refrigeration operation from time t ₁ to time t ₂ , the freezer damper 101 is closed (continuous), the vegetable damper 102 is opened from closed, and the first fan 9a is driven (OFF → ON) to perform an F-off cycle operation to cool the vegetable compartment 6. In this F-off cycle operation, the vegetable compartment 6 is cooled using the first evaporator 14a, which is kept at a low temperature by the freezing operation described below. Specifically, when the freezing operation ends and 10 minutes have elapsed at time t1 (steps S101 and S102), the first fan 9a is turned ON and the vegetable damper 102 is opened (step S103). During this time, heat is transferred to the first evaporator 14a to exchange heat with the air in the vegetable compartment 6, and the temperature T _DF of the first evaporator 14a rises. This operation is performed at the start of the freezing pre-operation (time t2) or until the crisper temperature T _V detected by the crisper temperature sensor 43 reaches T _Voff (time t ₄ ) (step S104). When the crisper temperature T _V reaches T _Voff (Yes in step S104), the crisper damper 102 is closed, and the first fan 9a is also stopped if the freezing operation is not in progress (steps S105 to S107).

The refrigerator compartment 2 is cooled by the refrigeration operation, and the refrigerator compartment temperature _TR detected by the refrigerator compartment temperature sensor 42 drops to _TRoff (step S7; time t2). When the freezing operation execution condition is satisfied (Yes in step S8), the refrigerator operation is switched to the freezing pre-operation (step S9). Note that even when the compressor 24 is stopped (step S2), if the freezing operation execution condition is satisfied (Yes in step S8), the freezing pre-operation is started. If the freezing operation execution condition is not satisfied (No in step S8), the compressor 24 is stopped (step S17).

In the freezing pre-operation, the three-way valve 52 is set to the outlet 52a side while the compressor 24 is driven (low speed → high speed), and the refrigerant flows into the first evaporator 14a. The first evaporator 14a, whose temperature has risen due to the refrigeration operation, the stop of the compressor 24 (step S2), and the F-off cycle operation, is cooled. During this time, the freezing chamber damper 101 is closed to suppress the blowing of air into the freezing chamber 7. Note that the blowing of air into the freezing chamber 7 may be suppressed by stopping the first fan 9a regardless of the state of the freezing chamber damper 101. In this way, the refrigerant flows into the first evaporator 14a while suppressing the blowing of air at a higher temperature than the freezing chamber 7 into the freezing chamber 7, thereby absorbing the heat stored in the first evaporator 14a by the F-off cycle operation (t ₁ to t ₂ ). In addition, the first fan 9a and the vegetable compartment damper 102 continue in their previous state, and when the freezer pre-operation is started during F-off cycle operation, the first fan 9a is driven (continued) and the vegetable compartment damper 102 is opened (maintained), thereby continuing to cool the vegetable compartment 6.

This freezing pre-operation is performed for 2 minutes (step S10; time t ₂ to t ₃ ), and the first evaporator 14a is cooled to a low temperature, after which the freezing operation (step S11) is started. In the freezing operation (step S11), the freezing chamber damper 101 is opened from the freezing pre-operation state, and the first fan 9a is driven (continued). Also, the rotation speed of the compressor 24 is made faster (L→H) than during the refrigeration operation. As a result, the air that has passed through the first evaporator 14a and become cold is blown into the freezing chamber 7, and the freezing chamber 7 is cooled. The cooling of the vegetable chamber 6 continues in the state during the freezing pre-operation, and if the vegetable chamber damper 102 is open and cooling is performed, the vegetable chamber damper 102 is opened even after the freezing operation, and the freezing chamber 6 is cooled together with the freezing chamber 7, and when the vegetable chamber temperature T _V detected by the vegetable chamber temperature sensor 43 reaches T _Voff , the vegetable chamber damper 102 is closed (step S106; time t ₄ ). In the section in which the freezer compartment 7 and the vegetable compartment 6 are cooled simultaneously, the rotation speed of the compressor 24 is set to high speed (H) to lower the temperature of the first evaporator 14a so that the heat of the air from the vegetable compartment 6 does not cause the temperature of the first evaporator 14a to rise excessively, making it impossible to cool the freezer compartment 7. When the cooling of the vegetable compartment 6 is completed, the rotation speed of the compressor 24 is set to medium speed (M) which is higher than that during refrigeration operation and slower than that during cooling of the vegetable compartment 6 in order to increase the cooling efficiency (steps S12 and S13).

When the freezing operation cools the freezing chamber 7, and the freezing chamber temperature T _F detected by the freezing chamber temperature sensor 41 drops to T _Foff and satisfies the freezing operation termination condition (Yes in step S14; time t ₅ ), the freezing operation is switched to the refrigerant recovery operation (step S15). In the refrigerant recovery operation (times t ₅ to t ₆ ), the compressor 24 is driven (continuously) with the three-way valve 52 fully closed to recover the refrigerant in the first evaporator 14a. As a result, the refrigerant in the first evaporator 14a is collected between the downstream side of the compressor 24 and the upstream side of the three-way valve 52 (a refrigerant flow path common to the refrigeration operation and the freezing operation). That is, the refrigerant is transferred to the refrigerant flow path used in the refrigeration operation, and a refrigerant shortage in the next refrigeration operation (times t ₆ to ) is suppressed. During the refrigerant recovery before the refrigeration operation (times t ₅ to t ₆ ), the first fan 9a is driven with the freezing chamber damper 101 open. The residual refrigerant in the first evaporator 14a is utilized to cool the freezing compartment 7, and the refrigerant in the first evaporator 14a evaporates and easily reaches the compressor 24, so that a large amount of refrigerant can be recovered in a relatively short time. This refrigerant recovery operation is performed for, for example, two minutes (step S16; time _t5 to _t6 ), and then the freezing operation is terminated (step S1). Thereafter, as with the above-mentioned time _t0 , the process returns to the refrigeration operation execution determination (steps S3 to S5) and the vegetable compartment cooling (steps S100 to S107).

Here, in the refrigerator 1 of the present embodiment, after the refrigeration operation is completed, the second fan 9b is driven (step S201) to perform an R-off cycle operation that cools the refrigerator compartment 2 and defrosts the second evaporator 14b. The R-off cycle operation is an operation in which the second fan 9b is driven during an operation in which the refrigerant is not flowed through the second evaporator 14b (freezing operation, stopping of the compressor 24, and refrigerant recovery), and air is circulated between the refrigerator compartment 2 and the second evaporator 14b to cool the refrigerator compartment 2 while melting the frost attached to the second evaporator 14b with air from the refrigerator compartment 2 at a refrigeration temperature (over 0°C). In this operation, when the second evaporator temperature T _DR detected by the second evaporator temperature sensor 40b becomes equal to or higher than T _DRoff (step S202; time t ₇ ), it is determined that the refrigerator compartment 2 cannot be cooled and the defrosting of the second evaporator 14b has also been completed, so the second fan 9b is stopped and the R-off cycle operation is terminated (step S203).

Next, the effects of the R-off cycle operation and the F-off cycle operation realized by the refrigerator 1 of this embodiment will be described below.
First, the F-off cycle operation will be described. In contrast to the F-off cycle operation in which the vegetable compartment 6 is cooled with no refrigerant flowing through the first evaporator 14a, the vegetable compartment 6 is cooled during freezing operation by refrigerant circulation cooling (t ₂ to t ₄ ). The F-off cycle operation is an operation in which the freezer compartment damper 101 is closed, the vegetable compartment damper 102 is opened, and the first fan 9a is driven during refrigeration operation in which no refrigerant flows through the first evaporator 14a or during stoppage of the compressor 24 (steps S1 and S103). Although no refrigerant flows through the first evaporator 14a, as shown at times t ₀ to t ₂ in FIG. 6, the first evaporator 14a is at a low temperature during the previous freezing operation. Therefore, when the first fan 9a is driven, the vegetable compartment damper 102 is opened, and air is circulated between the vegetable compartment 6 and the first evaporator 14a, heat exchange occurs between the vegetable compartment 6 and the first evaporator 14a, and the vegetable compartment 6 is cooled. The first evaporator 14a increases in temperature (stores heat) through heat exchange with the vegetable compartment 6, but in the subsequent pre-freezing operation, refrigerant flows into the first evaporator 14a, and the heat stored in the first evaporator 14a is recovered. During this F-off cycle operation, if air is circulated into the freezer compartment 7, the heat from the vegetable compartment 6 also flows into the freezer compartment 7, causing a rise in the temperature of food in the freezer compartment 7 and frosting in the freezer compartment 7 (due to moisture in the second switchable compartment 6A). In this embodiment, therefore, a freezer compartment damper 101 is provided and closed to prevent this.

On the other hand, refrigerant circulation cooling is performed by opening the vegetable compartment damper 102 during freezing operation in which the refrigerant is flowed through the first evaporator 14a to keep the temperature low (times _t3 to _t4 ), and the first fan 9a blows low-temperature air around the first evaporator 14a into the freezer compartment 7 and the vegetable compartment 6 to cool the vegetable compartment 6. Comparing the case where the vegetable compartment 6 is cooled only by refrigerant circulation cooling with the case where the F-off cycle operation achieved by providing the freezer compartment damper 101 is also used, the amount of heat absorbed by the refrigerant via the first evaporator 14a remains the same, but the present control in combination with the F-off cycle operation can increase the cooling efficiency and improve the energy saving performance. The reason for this will be explained below.

In the refrigeration cycle, the higher the evaporation temperature of the refrigerant, the higher the cooling efficiency, and the greater the amount of cooling even at the same rotation speed of the compressor 24. When cooling the freezer compartment 7 simultaneously in refrigerant circulation cooling in which the refrigerant flows through the first evaporator 14a, in order to cool the freezer compartment 7 together with the vegetable compartment 6, it is necessary to make the first evaporator 14a lower in temperature than the freezer compartment 7, and the vegetable compartment 6 is cooled with a relatively low refrigerant temperature. On the other hand, as in this embodiment, when the heat of the vegetable compartment 6 is transferred to the first evaporator 14a during F-off cycle operation and then the freezing operation (including pre-freezing operation) is performed, the temperature of the first evaporator 14a is high immediately after the start of the freezing operation that absorbs this heat, and the evaporation temperature of the refrigerant in the first evaporator 14a is also high. In other words, the heat of the vegetable compartment 6 absorbed during the F-off cycle operation can be absorbed by the refrigerant in a state of high cooling efficiency. As mentioned above, it is also possible to increase the rotation speed of the compressor 24 to make the first evaporator 14a cooler than the freezer compartment 7 when cooling the vegetable compartment 6, but by cooling the vegetable compartment 6 in advance during refrigeration operation, the time during which the compressor 24 rotates at a high speed can be reduced. Therefore, by performing F-off cycle operation with the freezer compartment damper 101 closed during refrigeration operation (or while the compressor 24 is stopped), the first fan 9a is driven and the vegetable compartment damper 102 is opened, energy saving performance can be improved.

In addition, by performing the F-off cycle operation, the freshness-keeping performance of the vegetable compartment 6 is improved. Basically, the lower the temperature of the first evaporator 14a, the easier it is for circulating air to frost on the first evaporator 14a and to be dehumidified. Since the temperature of the first evaporator 14a rises by performing the F-off cycle operation, the first evaporator temperature T _DF of the first evaporator 14a during cooling of the vegetable compartment 6 (including any of the F-off cycle operation, the pre-freezing operation, and the freezing operation) becomes relatively high, and dehumidification by the first evaporator 14a during cooling of the vegetable compartment 6 is suppressed. Therefore, the vegetable compartment 6 can be kept at a relatively high humidity, and the effect of improving the freshness-keeping performance of foods such as vegetables stored in the vegetable compartment 6 can be obtained.

The more frost there is on the first evaporator 14a, the greater the effect of this F-off cycle operation. The cooling efficiency improvement effect of the F-off cycle operation is achieved by utilizing heat storage in the first evaporator 14a. Therefore, when frost forms on the first evaporator 14a, the heat capacity of the frost that has adhered to the first evaporator 14a can also be used for the aforementioned heat storage, further enhancing the effect of the F-off cycle operation.

In addition, the effect of the deterioration of the heat exchange performance of the first evaporator 14a due to frost formation can also be suppressed. When the F-off cycle operation is performed, air above 0°C in the vegetable compartment 6 flows into the first evaporator 14a, some of the frost attached to the first evaporator 14a melts, and the melted water penetrates into the frost (air layer) (water fills the gaps). In the next freezing operation, this water freezes, and as the frost becomes closer to ice, the heat exchange performance of the first evaporator 14a improves. Basically, frost is prone to thermal resistance due to the air layer, that is, frost reduces the heat exchange performance between the first evaporator 14a and the surrounding air, but by making it into ice with less air inside, the thermal resistance is suppressed compared to the frost state, and the heat exchange performance of the first evaporator 14a improves. In addition, since ice has a higher density (smaller volume) than frost, when considering the same mass (moisture content), the air passage between the fins of the first evaporator 14a is less likely to be blocked, and the decrease in air volume due to the increase in ventilation resistance of the first evaporator 14a caused by frost can be suppressed.

As described above, the formation of frost enhances the cooling efficiency improvement effect of F-off cycle operation, and also suppresses the impact of the reduction in heat exchange performance of the first evaporator 14a caused by frost. This reduces the reduction in cooling efficiency caused by frost compared to when F-off cycle operation is not performed, and reduces the number of times the first evaporator 14a is defrosted, which means that the reduction in energy saving performance caused by defrosting can also be suppressed.

The refrigerator 1 of this embodiment is a refrigerator that has two evaporators (second evaporator 14b and first evaporator 14a) and cools by switching the evaporator through which the refrigerant flows (performs refrigeration operation and freezing operation). This reduces the problems that arise when a single evaporator is used to cool all storage compartments while performing off-cycle operation in which cooling is performed without flowing refrigerant through the evaporator.

In a refrigerator that uses one evaporator to cool the refrigerator compartment 2, freezer compartment 7, and vegetable compartment 6, in order to perform off-cycle operation in which the refrigerant is not flowing through the evaporator, it is necessary to provide a time for stopping the compressor 24. During this time, the refrigerant cannot absorb heat, so it is necessary to absorb heat from the refrigerator compartment 2, freezer compartment 7, and vegetable compartment 6 in a short operating time of the compressor 24. Therefore, compared to when the operating time of the compressor 24 is long (when the proportion of time the compressor 24 is operating is increased), heat is absorbed in a short time, so it is necessary to increase the rotation speed of the compressor 24 to lower the evaporation temperature, and this lowering of the evaporation temperature causes a decrease in cooling efficiency. This decrease in cooling efficiency reduces the cooling efficiency improvement effect of the off-cycle operation described above, and the effect of improving cooling efficiency could not be obtained sufficiently.

On the other hand, in the refrigerator 1 of this embodiment, even if the vegetable compartment 6 is cooled by the F-off cycle operation, the refrigerant can be flowed through the second evaporator 14b as a refrigeration operation and used to cool the refrigerator compartment 2, and the time can be utilized as heat absorption time by the refrigeration cycle. In other words, since the refrigerant absorbs heat inside the refrigerator 1 during the F-off cycle operation, there is no need to increase the speed of the compressor 24 to stop the compressor 24, and the cooling efficiency improvement effect of the F-off cycle operation can be fully obtained. In addition, since the refrigeration operation is an operation in which only the storage compartment in the refrigeration temperature range is cooled by the second evaporator 14b, it can be cooled at a higher evaporation temperature than the freezer compartment 7. Therefore, the cooling efficiency of the refrigerator compartment 2 can be higher than that of a refrigerator that cools the refrigerator compartment 2, the freezer compartment 7, and the vegetable compartment 6 with one evaporator.

As described above, the refrigerator 1 of this embodiment is provided with two evaporators (second evaporator 14b and first evaporator 14a) through which the refrigerant can flow alternately, one of the evaporators (first evaporator 14a) cools the storage compartments in the freezing temperature zone (freezer compartment 7) and the refrigerating temperature zone (vegetable compartment 6), and air flow control means (freezer compartment damper 101, vegetable compartment damper 102) are provided in all storage compartments (freezer compartment 7 and vegetable compartment 6) cooled by this evaporator. This allows off-cycle operation (F off-cycle operation) to be performed without stopping the compressor 24, and the cooling efficiency improvement effect due to the off-cycle operation can be fully obtained, that is, a refrigerator 1 with high energy-saving performance can be obtained.

In addition, by configuring the other evaporator (second evaporator 14b) to cool only the storage compartment in the refrigeration temperature range (refrigeration compartment 2), even when refrigerant is flowing, the storage compartment in the refrigeration temperature range (refrigeration compartment 2) can be cooled at a higher evaporation temperature than the storage compartment in the freezing temperature range (freezing compartment 7), further improving the cooling efficiency (see the second evaporator temperature _TDR from time _t0 to _t2 and the first evaporator temperature _TDF from time _t3 to _t5 ).

Furthermore, in the refrigerator 1 of this embodiment, R off-cycle operation is also performed, and the off-cycle operation also improves the energy-saving performance of the refrigerator compartment 2. During the refrigerant recovery operation and the freezing operation, the refrigerant cannot flow through the second evaporator 14b, but the refrigerator compartment 2 can be cooled by cooling the second evaporator 14b itself and the frost attached to the second evaporator 14b. In particular, when the frost attached to the second evaporator 14b is below 0°C, the heat of melting the frost can be used to cool the refrigerator compartment 2, and the refrigerator compartment 2 can be maintained at a low temperature (temperature rise can be suppressed). Since the temperature rise of the refrigerator compartment 2 is suppressed, the freezing operation can be performed for a relatively long time, and the rotation speed of the compressor 24 during the freezing operation can be made relatively slow, improving the energy-saving performance.

In addition, by performing the R off cycle operation, the second evaporator 14b and its surroundings can be heated, and the following effects can be obtained. That is, during the freezing pre-operation, freezing operation, and refrigerant recovery operation, the refrigerant is prevented from flowing through the second evaporator 14b. When the air in the refrigerator compartment 2 passes through the second evaporator 14b, the second evaporator 14b and the frost attached to the second evaporator 14b are heated by heat exchange with the refrigerator compartment 2, which has a higher temperature than the second evaporator 14b. This makes it possible to melt the frost attached to the second evaporator 14b without using a heater, and to discharge the frost or melt the frost once to turn it into ice, thereby increasing the density and thermal conductivity, and suppressing the increase in ventilation resistance and the decrease in heat transfer efficiency of the second evaporator 14b due to frost. That is, the cooling efficiency can be increased, and energy saving performance can be improved. In addition, by discharging part or all of the frost during the cooling operation, the effect of shortening the time for R defrosting (see FIG. 7B), which will be described later, can be obtained.

As described above, the refrigerator 1 of this embodiment is provided with two evaporators, the first evaporator 14a and the second evaporator 14b, through which the refrigerant can flow alternately. As a result, the first evaporator 14a, which cools the storage compartment (freezer compartment 7) in the freezing temperature range and the storage compartment (vegetable compartment 6) in the refrigerating temperature range, efficiently cools the storage compartment (vegetable compartment 6) in the refrigerating temperature range by F off cycle operation. In addition, the second evaporator 14b, which cools only the storage compartment (refrigerating compartment 2) in the refrigerating temperature range, efficiently cools the storage compartment (refrigerating compartment 2) in the refrigerating temperature range by R off cycle operation. In other words, the storage compartment in the refrigerating temperature range cooled by either evaporator can be efficiently cooled using the off cycle operation. In addition, the second evaporator 14b, which cools only the storage compartment (refrigerating compartment 2) in the refrigerating temperature range, can also defrost the second evaporator 14b by R off cycle operation, and the amount of power consumption due to the defrosting operation can be reduced, resulting in a refrigerator with high energy saving performance.

In addition, in order to reliably obtain and further enhance the above-mentioned effects, the refrigerator 1 of this embodiment is configured and controlled as follows.
In the refrigerator 1 of this embodiment, as a member (rear partition member) separating the freezer compartment 7 and the first evaporator compartment 8a, polypropylene (resin member) is used for the partition member 20a constituting the wall surface on the freezer compartment 7 side, and polystyrene foam (foam member) having a smaller heat capacity per unit volume than the partition member 20a is used for the partition member 20b constituting the first evaporator compartment 8a side. Polypropylene has a density of about 910 kg/m ³ , a specific heat of about 1.7 kJ/(kg·K), and a heat capacity per unit volume (product of specific heat and density) of about 1500 kJ/(m ³ ·K). Polystyrene foam has a density of about 40 kg/m ³ , a specific heat of about 1.8 kJ/(kg·K), and a heat capacity per unit volume of about 70 kJ/(m ³ ·K). In this way, the foamed polystyrene foam (partition member 20b) has a lower density and a smaller heat capacity per unit volume than the polypropylene (partition member 20a). When the heat capacity per unit volume is small, the temperature changes with a small amount of heat, and therefore the foam has a high ability to follow the surrounding temperature.

Here, during F-off cycle operation, the temperature of the first evaporator chamber 8a increases because return air from the vegetable compartment 6 flows through it, and during freezing operation, the temperature of the first evaporator chamber 8a decreases due to the first evaporator 14a. That is, the temperature fluctuation of the first evaporator chamber 8a increases due to the F-off cycle operation. This temperature fluctuation causes a temperature difference between the first evaporator chamber 8a and the wall surface of the partition member 20b on the first evaporator chamber 8a side, and heat exchange occurs between the first evaporator chamber 8a and the partition member 20b. Specifically, during F-off cycle operation, the temperature of the first evaporator chamber 8a increases, but since the partition member 20b is at a low temperature during the previous freezing operation, heat is transferred from the first evaporator chamber 8a to the partition member 20b, and during freezing operation, the first evaporator chamber 8a decreases in temperature due to the first evaporator 14a, and the partition member 20b also absorbs heat. When heat is transferred to the partition member 20b during F-off cycle operation, the temperature of the first evaporator 14a becomes harder to increase, so the effect of the temperature increase of the first evaporator 14a during the F-off cycle operation described above is reduced.

In response to this, by using a low heat capacity material for the partition member 20b, it is possible to improve the temperature tracking ability of the first evaporator chamber 8a. This reduces the temperature difference between the first evaporator chamber 8a and the wall surface of the partition member 20b on the first evaporator chamber 8a side during F-off cycle operation, making it possible to suppress heat exchange between the first evaporator chamber 8a and the partition member 20b caused by the temperature difference. In other words, it is possible to further enhance the effect of the temperature rise of the first evaporator 14a during the aforementioned F-off cycle operation.

In addition, in the refrigerator 1 of this embodiment, the F-off cycle operation is performed after a predetermined time has elapsed after the end of the freezing operation (steps S101 and S102). As described above, the lower the temperature of the first evaporator 14a, the easier it is to dehumidify the first evaporator 14a. Therefore, by avoiding the time immediately after the end of the freezing operation when the first evaporator 14a is at its lowest temperature, the dehumidification in the first evaporator 14a is suppressed and the freshness-keeping performance is improved. Since the purpose is to suppress the blowing of air to the vegetable compartment 6 when the first evaporator 14a is at a low temperature, the F-off cycle operation may be started not after the elapsed time from the end of the freezing operation, but after the first evaporator temperature sensor 40a detects that the temperature T _DF of the first evaporator 14a has reached a predetermined temperature or higher.

The configuration of the refrigerator 1 of this embodiment is also effective in reducing the amount of power consumed during defrosting. Note that the F defrosting operation (F first defrost, F second defrost) is an operation that defrosts the first evaporator 14a, which also cools the storage compartment at the freezing temperature. In this embodiment, during this F defrosting operation, the R defrosting operation, which is a defrosting operation of the second evaporator 14b, is also performed.

7A and 7B are flowcharts showing defrosting operation control of the refrigerator according to the first embodiment.
As shown in Fig. 7A, in the refrigerator 1 of this embodiment, during the cooling operation (step S21) described in Figs. 5A to 5C and 6, the control device (control board 31) determines whether or not the defrosting operation start condition is satisfied (step S22). The defrosting operation start condition is determined, for example, from the number of times the doors 2a, 2b, 3a, 4a, 5a, and 6a are opened and closed, and the total driving time of the compressor 24. If the control device determines that the defrosting operation start condition is not satisfied (S22, No), the process returns to step S21, and if the control device determines that the defrosting operation start condition is satisfied (S22, Yes), the process proceeds to step S23.

In step S23, the control device starts pre-cool operation. In pre-cool operation, refrigeration operation and R-off cycle operation are performed. The refrigeration operation and R-off cycle operation are the same as those described in Figures 5 and 6.

In step S24, the control device determines whether or not the pre-cool operation has ended. The end of the pre-cool operation can be determined, for example, by the passage of a predetermined time. If the control device determines that the pre-cool operation has not ended (S24, No), it repeats the processing of step S24, and if the control device determines that the pre-cool operation has ended (S24, Yes), it proceeds to step S25.

In step S25, the control device fully closes the three-way valve 52, turns off (stops) the compressor 24, and turns on the defrost heater 21, transitioning to F first defrost.

In step S26, the control device closes the freezer damper 101, opens the vegetable compartment damper 102, and turns on the first fan 9a.

In step S27, the control device judges whether the temperature _TV of the vegetable room 6 detected by the vegetable room temperature sensor 43 is equal to or lower than the predetermined temperature _TVHoff , or whether the temperature _TDF of the first evaporator 14a detected by the first evaporator temperature sensor 40a is equal to or higher than the predetermined temperature _TDFoff2 . The predetermined temperature _TVHoff is determined by a prior test and is set to, for example, 6°C. If the control device judges that the temperature _TV is not equal to or lower than the predetermined temperature _TVHoff (S27, No), or if the control device judges that the temperature _TDF is not equal to or higher than the predetermined temperature _TDFoff2 (S27, No), the control device repeats the process of step S27. If the control device judges that the temperature _TV is equal to or lower than the predetermined temperature _TVHoff (S27, Yes), or if the control device judges that the temperature _TDF is equal to or higher than the predetermined temperature _TDFoff2 (S27, Yes), the control device proceeds to the second defrosting F of step S28.

In step S28, the control device opens the freezer damper 101, closes the vegetable compartment damper 102, and turns off (stops) the first fan 9a.

In step S29, the control device determines whether the temperature T _DF of the first evaporator 14a is equal to or higher than a predetermined temperature T _DFoff . The predetermined temperature T _DFoff is determined by a prior test and is set to, for example, 10° C. If the control device determines that the temperature T _DF is not equal to or higher than the predetermined temperature T _DFoff (S29, No), the control device repeats the process of step S29. If the control device determines that the temperature T _DF is equal to or higher than the predetermined temperature T _DFoff (S29, Yes), the control device proceeds to step S30.

In step S30, the control device turns off (stops) the defrost heater 21.

In step S31, the control device drains the water that has melted due to defrosting.

In addition, in parallel with the F first defrost, the R defrost shown in FIG. 7B is performed. That is, as shown in FIG. 7B, in step S211, the control device turns on (energizes) the second fan 9b.

In step S212, the control device judges whether the temperature _TDR of the second evaporator 14b detected by the second evaporator temperature sensor 40b is equal to or higher than a predetermined temperature _TDRoff . The predetermined temperature _TDRoff is determined by a prior test and is set to, for example, 3°C. If the control device judges that the temperature _TDR is not equal to or higher than the predetermined temperature _TDRoff (S212, No), it repeats the process of step S212, and if the control device judges that the temperature _TDR is equal to or higher than the predetermined temperature _TDRoff (S212, Yes), it proceeds to step S213.

In step S213, the control device starts a timer (Δt _da ).

In step S214, the control device determines whether the elapsed time Δt _da is equal to or greater than a fourth predetermined time. The fourth predetermined time (Δt _da1 ) is determined by a prior test and is set to, for example, 30 minutes. If the control device determines that the elapsed time Δt _da is equal to or greater than the fourth predetermined time (S214, Yes), the control device proceeds to step S215, and if the elapsed time Δt _da is not equal to or greater than the fourth predetermined time (S214, No), the control device repeats the process of step S214.

In step S215, the control device turns off (stops) the second fan 9b and ends the process.

FIG. 8 is a time chart showing the defrosting operation control of the refrigerator according to the first embodiment.
As shown in Fig. 8, when the defrosting operation start condition is satisfied (time _td0 ), the refrigerator 1 of this embodiment transitions to pre-cool operation in which freezing operation and R off cycle operation are performed (step S23). By performing freezing operation (F operation) before starting the defrosting operation, it is possible to suppress melting of frozen foods, ice, etc. due to a rise in temperature in the freezer compartment 7 during the F defrosting operation. In addition, by performing the R off cycle operation (turning the second fan 9b ON) before starting the defrosting operation, the second evaporator 14b and the frost adhering to the second evaporator 14b are heated, so that the R defrosting operation described below is completed in a short time.

During this freezing operation, it is advisable to close the vegetable compartment damper 102. This allows the F defrosting described below to be started when the temperature in the vegetable compartment 6 is relatively high, and promotes the heating of the first evaporator 14a using the heat from the vegetable compartment 6.

When the pre-cool operation end condition is satisfied by performing this pre-cool operation for a predetermined time, for example, 30 minutes (time t _d0 to t _d1 ) (step S24), the three-way valve 52 is fully closed, the compressor 24 is turned OFF, and the defrost heater 21 is turned ON to start the F-first defrost operation (step S25). In addition, in the refrigerator 1 of this embodiment, the freezer damper 101 is closed to suppress the temperature rise of the freezer chamber 7, while the vegetable chamber damper 102 is opened and the first fan 9a is turned ON (continuous) (step S26), air is circulated between the vegetable chamber 6 and the first evaporator chamber 8a, and heat exchange is performed between the vegetable chamber 6 and the first evaporator 14a. This defrosting is called the F-first defrosting. In this F-first defrosting, the first evaporator 14a is heated by the air from the vegetable chamber 6, which is hotter than the first evaporator 14a, together with the heat from the defrost heater 21, to defrost the first evaporator 14a.

Thereafter, when the temperature _TV of the vegetable compartment 6 becomes equal to or lower than _TVHoff (step S27 is Yes; time _td2 ), in order to prevent the vegetable compartment 6 from being overcooled, the vegetable compartment damper 102 is closed, the first fan 9a is turned OFF, the freezer compartment damper 101 is opened, and the first evaporator 14a is heated only by the defrost heater 21 (step S28). In the F-second defrost, the first fan 9a is turned OFF, but the freezer compartment damper 101 is opened so that the high-temperature air around the defrost heater 21 flows upward to the first evaporator 14a even after time _td2 , allowing the air of the first evaporator chamber 8a to circulate through the freezer compartment 7. Note that the F-second defrost also occurs when the temperature _TDF of the first evaporator 14a becomes higher than a predetermined temperature so that the air from the first evaporator chamber 8a does not heat the vegetable compartment 6 (see step S27).

Then, when the temperature T _DF of the first evaporator 14a detected by the first evaporator temperature sensor 40a reaches T _DFoff (e.g., 10°C) that is sufficiently higher than the ice melting temperature (about 0°C), it is determined that the frost on the first evaporator 14a has melted, and the F defrosting operation (F second defrosting operation) is terminated (steps S29, S30; time t _d3 ). After the F defrosting operation is terminated, the system is stopped for a drainage time of, for example, 3 minutes (step S31; time t _d4 ), and then the freezing operation (step S32) is started.

Heating by the defrost heater 21, which is an electric heater, generally consumes a lot of power because the amount of heat generated is consumed by passing power through the heater (for example, about 150 W). On the other hand, heating by heat exchange with the air in the vegetable compartment 6 can be done with only the driving force of the first fan 9a (about 3 W), and in addition, the vegetable compartment 6 is cooled by heat exchange with the air in the vegetable compartment 6. Therefore, by combining this method of circulating air between the vegetable compartment 6 and the first evaporator chamber 8a, the amount of power consumed during defrosting operation can be reduced compared to when only an electric heater is used, which means that energy saving performance can be improved.

In the explanation of Figures 7 and 8, the temperature in the vegetable compartment 6 is detected and the F-first defrost is switched to the F-second defrost, but when the outside air temperature is low and the outside air temperature is low as detected by the outside air temperature sensor 37, which makes it easy for the temperature in the vegetable compartment 6 to become low, the F-first defrost may be omitted or may be shortened beforehand and the F-second defrost may be started. This makes it easier to prevent the temperature of food in the vegetable compartment 6 from becoming low.

Next, the R defrosting operation will be described. In the R defrosting operation, an electric heater is not used, and the second fan 9b is driven to circulate air between the refrigerator compartment 2 and the second evaporator compartment 8b, thereby exchanging heat between the refrigerator compartment 2 and the second evaporator 14b, and the frost on the second evaporator 14b is melted by the heat of the air in the refrigerator compartment 2. This allows the second evaporator 14b to be defrosted with less power consumed by the second fan 9b, and in addition, the refrigerator compartment 2 can be cooled, resulting in a defrosting method with high energy-saving performance.

When starting R defrost, first, the second fan 9b is driven (step S211; time _td1 ). When the temperature _TDR of the second evaporator 14b detected by the second evaporator temperature sensor 40b becomes equal to or higher than _TDRoff , which is equal to or higher than 0°C (e.g., 3°C) (Yes in step S212; time _td5 ), the timer _Δtda is started (step S213). Then, when a predetermined time _Δtda1 (e.g., 20 minutes) has elapsed (Yes in step S214), the second fan 9b is stopped and R defrost is terminated (step S215; time _td6 ).

In this R defrosting operation, the temperature T _DR of the second evaporator 14b is kept at or above 0° C., and the operation is further moved by a fourth predetermined time Δt _da1 , thereby ensuring that the frost on the second evaporator 14b can be melted and discharged. Even if the temperature of the second evaporator temperature sensor 40b rises due to air bypassing the frosting section when frost still remains, air at or above 0° C. flows through and around the second evaporator 14b for at least Δt _da1 , thereby preventing residual frost and ensuring that the second evaporator 14b can be defrosted.

In addition, since air of 0° C. or higher can be blown at least Δt _da1 to the second fan 9b, the refrigerator compartment duct 11, and the like, which are located downstream of the second evaporator 14b, the frost can be melted even if frost has formed in these locations. In particular, if frost grows on the second fan 9b, the second fan 9b cannot be operated, which has a significant effect on cooling control. Therefore, in this configuration in which the second fan 9b is provided downstream of the second evaporator 14b, it is effective to drive the second fan 9b for a predetermined time even after the temperature of the second evaporator 14b reaches or exceeds T _DRoff , which is 0° C. or higher, to suppress frost growth on the second fan 9b.

Due to these configurations and controls, the refrigerator 1 of this embodiment is a refrigerator with high energy-saving performance in defrosting operation. Since the configuration of this embodiment has two evaporators, in addition to the first evaporator 14a, defrosting operation of the second evaporator 14b is also required, but as described above, the defrosting operation of the second evaporator 14b (R defrosting) has high energy-saving performance and has little impact on power consumption. On the other hand, compared to a refrigerator that cools all storage compartments with one evaporator, frosting of the first evaporator 14a is suppressed by eliminating frosting from the refrigerator compartment 2, and the frequency of defrosting operation of the first evaporator 14a can be reduced and the time of defrosting operation of the first evaporator 14a can be shortened. In addition, as described above, the heat of the air in the vegetable compartment 6 is also used to defrost the first evaporator 14a, improving energy-saving performance. In addition, because the vegetable compartment 6 is cooled by the F first defrost and the refrigerator compartment 2 is cooled by the R defrost, it is possible to concentrate on cooling the freezer compartment 7 after the defrost operation is completed, and the rotation speed of the compressor 24 after the defrost operation is completed can be made relatively slow, improving energy saving performance. Therefore, by configuring as in this embodiment, the energy saving performance of the defrost operation is also improved compared to a refrigerator that cools the refrigerator compartment 2, the freezer compartment 7, and the vegetable compartment 6 with a single evaporator.

In addition, by performing the F first defrost, the defrosting efficiency of parts other than the first evaporator 14a can also be improved. For example, the first fan 9a is located farther from the defrost heater 21 than the first evaporator 14a and the like, and the heat of the defrost heater 21 does not reach the first fan 9a sufficiently by natural convection, but by performing the F first defrost, which is forced convection, the heat can easily reach the periphery of the first fan 9a. In other words, even if frost adheres to the first fan 9a and the like that are relatively far from the defrost heater 21, the frost can be efficiently melted.

As described above, the refrigerator 1 of the first embodiment includes a first refrigerant flow path R1 through which the refrigerant flows in the order of the compressor 24, the external radiator 50a, the wall surface heat radiation pipe 50b, the condensation prevention pipe 50c, the three-way valve 52, the freezing capillary tube 53a, and the first evaporator 14a. The refrigerator 1 also includes a second refrigerant flow path R2 through which the refrigerant flows in the order of the compressor 24, the external radiator 50a, the wall surface heat radiation pipe 50b, the condensation prevention pipe 50c, the three-way valve 52, the refrigeration capillary tube 53b, and the second evaporator 14b. The refrigerator 1 also includes a first fan 9a that blows air cooled by the first evaporator 14a, and a freezer compartment 7 and a vegetable compartment 6 to which air is blown by the first fan 9a. The refrigerator 1 also includes a second fan 9b that blows air cooled by the second evaporator 14b, and a refrigerator compartment 2 to which air is blown by the second fan 9b. In addition, the refrigerator 1 is equipped with a freezer damper 101 that suppresses (blocks) the air sent from the first fan 9a to the freezer chamber 7. This allows off-cycle operation (F off-cycle operation) to be performed while the compressor 24 is running, realizing a refrigerator with even higher cooling efficiency.

The first embodiment also includes a control device (control board 31) that executes an operation to cool the refrigerator compartment 2 by driving the first fan 9a to blow air into the vegetable compartment 6 while suppressing the blowing of air from the first fan 9a to the freezer compartment 7, and driving the second fan 9b while flowing refrigerant through the second refrigerant flow path R2. With this, off-cycle operation (F off-cycle operation) can be performed without stopping the compressor 24, which was previously not possible without stopping the compressor. Also, unlike the conventional method, which required early cooling in order to stop the compressor, such control is no longer necessary.

The first embodiment also includes a defrost heater 21 that heats the first evaporator 14a to melt frost. The control device suppresses the blowing of air from the first fan 9a to the freezer compartment 7, while energizing the defrost heater 21 and driving the first fan 9a to blow air to the vegetable compartment 6 (t _d1 to t _d2 in FIG. 8 ). This allows the rotation speed of the compressor 24 after the defrosting operation to be set to a relatively low speed, thereby improving energy saving performance. Furthermore, the energy saving performance of the defrosting operation can be improved compared to a refrigerator that cools the refrigerator compartment 2, the freezer compartment 7, and the vegetable compartment 6 with one evaporator.

In the first embodiment, the vegetable chamber 6 is provided substantially in front of the first evaporator 14a, and a partition member 20b is provided to separate the vegetable chamber 6 from the first evaporator 14a. The partition member 20b is made of foamed polystyrene foam (expanded polystyrene). This reduces the temperature difference between the first evaporator chamber 8a and the wall surface of the partition member 20b on the first evaporator chamber 8a side during F-off cycle operation, and suppresses heat exchange between the first evaporator chamber 8a and the partition member 20b due to the temperature difference. In other words, the effect of the temperature rise of the first evaporator 14a during F-off cycle operation can be further enhanced.

Second Embodiment
A refrigerator according to the second embodiment will be described below. Fig. 9 is a cross-sectional view of the refrigerator according to the second embodiment. Fig. 10 is a front view showing an air passage configuration of the refrigerator according to the second embodiment. Fig. 11 is a rear view of the interior of the refrigerator according to the second embodiment. Fig. 12 is a schematic view showing an air passage configuration of the refrigerator according to the second embodiment. The refrigerator 1A according to the second embodiment is provided with a switchable storage compartment that can be switched between a refrigeration temperature zone and a freezing temperature zone, instead of the lower freezer compartment 5 and the vegetable compartment 6 according to the first embodiment. In the following description, configurations similar to those of the first embodiment will be omitted.

As shown in FIG. 9, the insulated box 10 of the refrigerator 1A has storage compartments in the following order from the top: the refrigerator compartment 2, the ice-making compartment 3 and upper freezer compartment 4 on the left and right, the first switchable compartment 5A, and the second switchable compartment 6A. The ice-making compartment 3 and upper freezer compartment 4 are separated from the first switchable compartment 5A by an insulated partition wall 30a. The first switchable compartment 5A and the second switchable compartment 6A are separated by an insulated partition wall 29a. Vacuum insulation material 25 is inserted inside the insulated partition walls 29a and 30a, ensuring high insulation performance with a relatively thin insulating wall.

In addition, since the first and second switching compartments 5A and 6A can be relatively large freezer storage compartments depending on the settings, vacuum insulation material 25 is inserted into the door 5a of the first switching compartment 5A, the door 6a of the second switching compartment 6A, and the lower part of the insulated box body 10 to improve the insulation performance.

The first and second switching compartments 5A and 6A are switching compartments that can be set to a freezing temperature zone or a refrigerating temperature zone, and can be switched between a refrigerating mode that sets the temperature at about 4°C on average and a freezing mode that sets the temperature at about -20°C on average. In order to control the temperatures of the first and second switching compartments 5A and 6A within an appropriate range, a first switching compartment temperature sensor 44 and a second switching compartment temperature sensor 45 are provided in each storage compartment. The refrigerator 1A of this embodiment further has multiple operating modes, such as a strong refrigerating mode and a weak freezing mode that set the temperature between the refrigerating mode and the freezing mode, a strong freezing mode that sets the temperature lower than the freezing mode, and a vegetable mode that is suitable for storing vegetables in the refrigerating temperature zone, and these operating modes can be selected by the user using the operation unit 26. In addition, when the refrigerator 1A is connected to a smartphone or the like via a wireless communication line, the user may be able to set the temperature zone of the switching storage compartment via the smartphone or the like.

The first evaporator 14a and the first evaporator chamber 8a are provided at the rear of the first switching chamber 5A and the second switching chamber 6A. The first evaporator chamber 8a is separated from the first switching chamber 5A and the second switching chamber 6A by partition members 20a and 20b. The partition members 20a on the first switching chamber 5A side and the second switching chamber 6A side are made of a resin member. The partition member 20b on the first evaporator chamber 8a side is made of expanded polystyrene, which is a foam insulation material.

As shown in Figs. 10 to 12, in the refrigerator 1A of the second embodiment, the ice making compartment 3, the freezer compartment 4, the first switching compartment 5A, and the second switching compartment 6A are cooled by air (cold air) that has been cooled by the first evaporator 14a. The blowing of cold air to the first switching compartment 5A and the second switching compartment 6A is controlled by the freezer compartment damper 200, the first switching compartment damper 201, and the second switching compartment damper 202, which are the air blowing control units. In the second embodiment, since the front of the first fan 9a is a storage compartment that is also in the refrigeration temperature range, insulation from the first evaporator compartment 8a, etc. is required, and the air path is complicated, a turbo fan, which is a centrifugal fan that is resistant to static pressure, is used. In addition, since the first switching compartment 5A and the second switching compartment 6A are also intended to be used as low-temperature freezer compartments, the first switching compartment damper 201 and the second switching compartment damper 202, which control the blowing of cold air to the first switching compartment 5A and the second switching compartment 6A, need to have a relatively large air volume. For this reason, the opening is larger than that of a damper designed to blow air only into a storage compartment in the refrigeration temperature range (for example, the vegetable compartment damper 102 in the first embodiment).

When cooling the ice-making chamber 3 and the upper freezer chamber 4, the first fan 9a is driven with the freezer chamber damper 200 open. The air in the first evaporator chamber 8a, cooled by the first evaporator 14a, is pressurized by the first fan 9a and flows through the freezer chamber damper 200, the freezer chamber air duct 12, and the freezer chamber outlet 12a to the ice-making chamber 3 and the upper freezer chamber 4. The air that has cooled the ice-making chamber 3 and the freezer chamber 4 returns to the first evaporator chamber 8a from the freezer chamber return port 12b through the freezer chamber return air duct 12c, and is cooled again by the first evaporator 14a.

When cooling the first switching chamber 5A, the first switching chamber damper 201 is opened. The air in the first evaporator chamber 8a cooled by the first evaporator 14a is blown into the first switching chamber 5A through the first fan 9a, the first switching chamber damper 201, the air passage 111, and the first switching chamber outlet 111a (see FIG. 11), which is the outlet of the first switching chamber 5A. The cold air blown into the first switching chamber 5A is blown toward the first switching chamber container 5c (see FIG. 9) so that the food in the first switching chamber container 5c can be cooled in a short time, considering its use as a low-temperature freezer. The air that has cooled the first switching chamber 5A returns to the first evaporator chamber 8a through the first switching chamber return port 111b (see FIG. 10 and FIG. 11) and the freezer chamber return air passage 12c, and is cooled again by the first evaporator 14a.

When cooling the second switching chamber 6A, the second switching chamber damper 202 is opened. The air in the first evaporator chamber 8a cooled by the first evaporator 14a is blown into the second switching chamber 6A via the first fan 9a, the second switching chamber damper 202, the air passage 112, and the second switching chamber outlet 112a (see FIG. 11), which is the outlet of the second switching chamber 5A. The cold air blown into the second switching chamber 6A is blown toward the second switching chamber container 6c so that the food in the second switching chamber container 6c can be cooled in a short time, considering its use as a freezer. The air that has cooled the second switching chamber 6A returns to the first evaporator chamber 8a through the second switching chamber return port 112b and is cooled again by the first evaporator 14a.

Next, the control in the second embodiment will be described in comparison with the first embodiment.
The table shown in Fig. 13 summarizes the control in each mode in the first and second embodiments. Each operation is similar to that shown in Figs. 5 to 8 in the first embodiment.

The second embodiment is basically similar to the first embodiment in the conditions and methods for performing each operation, such as refrigeration operation (R operation), freezing operation (F operation), and F off cycle operation. On the other hand, the damper opening and closing conditions differ depending on the mode setting of the first switchable compartment 5A and the second switchable compartment 6A. The damper that controls the airflow to the ice making compartment 3, the upper freezer compartment 4, and the switchable compartment set to the freezer mode performs the same opening and closing control as the freezer compartment damper 101 in the first embodiment, and the damper that controls the airflow to the switchable compartment set to the refrigeration mode performs the same opening and closing control as the vegetable compartment damper 102 in the first embodiment.

Here, an example will be described in which the first switching compartment 5A is in refrigeration mode and the second switching compartment 6A is in freezing mode. The cooling of the refrigerator compartment 2 is the same as in the first embodiment. The ice making compartment 3, the upper freezer compartment 4, and the second switching compartment 6A in the freezing temperature zone are cooled in freezing operation with the compressor 24 ON, the three-way valve 52 set to the 52a side (see FIG. 4), the first fan 9a ON, and the freezer compartment damper 200 and the second switching compartment damper 202 open. The first switching compartment 5A in the freezing temperature zone is cooled in F-off cycle operation with the first fan 9a ON and the first switching compartment damper 201 open during refrigeration operation, as in the vegetable compartment 6 in the first embodiment. If the first evaporator temperature sensor 40a that detects the temperature of the first switching compartment 5A does not reach a predetermined temperature during that time, the first switching compartment damper 201 is opened and cooling is continued even in freezing operation. During defrosting operation, the first fan 9a is turned on and the first switching compartment damper 201 is opened to cool the first switching compartment 5A in the refrigeration temperature range and to promote heating of the first evaporator 14a by the heat of the air in the first switching compartment 5A, and the F first defrosting operation is performed similarly to the first embodiment. During F off cycle operation and F first defrosting operation, the freezer compartment damper 200 and the second switching compartment damper 202 are closed to suppress temperature rise in the ice making compartment 3, the upper freezer compartment 4, and the second switching compartment 6A in the freezing temperature range.

In addition, when the first switching chamber 5A is set to the freezing mode and the second switching chamber 6A is set to the refrigeration mode, the control of the first switching chamber damper 201 and the second switching chamber damper 202 is reversed from the above-mentioned case where the first switching chamber 5A is set to the refrigeration mode and the second switching chamber 6A is set to the freezing mode.

In addition, when the first switching chamber 5A and the second switching chamber 6A are set to the refrigeration mode, the second switching chamber damper 202 is also controlled in the same manner as the opening and closing control of the first switching chamber damper 201 when the first switching chamber 5A is set to the refrigeration mode and the second switching chamber 6A is set to the freezing mode.

When both the first and second switchable compartments 5A and 6A are in the freezing mode, all storage compartments cooled by the first evaporator 14a (ice-making compartment 3, upper freezer compartment 4, first switchable compartment 5A, and second switchable compartment 6A) are in the freezing temperature range, so F off cycle operation and F first defrost operation, which cool the storage compartments in the refrigeration temperature range and use the heat from the storage compartments in the refrigeration temperature range to defrost the first evaporator 14a, are not performed.

During F second defrost operation, the first switching chamber damper 201 is opened regardless of the mode. This is to promote air flow by natural convection, so that air can circulate from the defrost heater 21 to the first evaporator 14a via the shortest route (in the order of defrost heater 21, first evaporator 14a, first fan 9a, first switching chamber damper 201, first switching chamber outlet 111a, first switching chamber 5A, first switching chamber return port 111b, and defrost heater 21).

As described above, even in the second embodiment that includes switching compartments (first switching compartment 5A and second switching compartment 6A), F off cycle operation and F first defrost can be performed except when both the first switching compartment 5A and the second switching compartment 6A are in the freezing mode, i.e., the same effects as in the first embodiment can be obtained.

Here, the first switching chamber 5A and the second switching chamber 6A are also intended to be used as low-temperature freezer chambers, so that the first switching chamber outlet 111a (see FIG. 11) and the second switching chamber outlet 112a (see FIG. 11) are configured to discharge air directly into the containers of the storage chambers (first switching chamber container 5c, second switching chamber container 6c) to cool food with low-temperature cold air. On the other hand, when the first switching chamber 5A and the second switching chamber 6A are in the refrigeration mode, when the first switching chamber damper 201 and the second switching chamber damper 202 are opened to cool the first switching chamber 5A and the second switching chamber 6A, the low-temperature and low-humidity air from the first evaporator 14a is likely to reach the food directly from the first switching chamber outlet 111a and the second switching chamber outlet 112a, and the food near the first switching chamber outlet 111a and the second switching chamber outlet 112a is likely to dry out. This effect is particularly significant when vegetables are allowed to be stored in the first switching chamber 5A and the second switching chamber 6A. In contrast, the refrigerator 1A of the second embodiment reduces this effect by cooling the first and second switching compartments 5A and 6A set in the refrigeration mode using the F-off cycle operation. As described in the first embodiment, compared to cooling in the freezing mode, the temperature of the first evaporator 14a is higher when cooling using the F-off cycle operation, and dehumidification in the first evaporator 14a is suppressed, so the air blown from the first evaporator 14a to the storage compartment becomes relatively humid. In other words, by cooling the first and second switching compartments 5A and 6A in the refrigeration mode using the F-off cycle operation, drying of food can be relatively suppressed even if the discharged air reaches the food directly.

As described above, in refrigerators that have storage compartments that can be set to the refrigeration temperature range and in which the exhaust air is blown directly into food containers, the dehumidification suppression effect of this F-off cycle is particularly effective in improving freshness performance.

In addition, in a refrigerator 1A equipped with a switching compartment (first switching compartment 5A, second switching compartment 6A) as in the second embodiment, the effect of improving energy saving performance during defrosting by F first defrost is also higher. In a refrigerator 1A equipped with a switching compartment, the air passage is likely to be complicated in order to accommodate both the refrigeration mode and the freezing mode, and with natural convection alone, the convection flow of the heat around the defrost heater 21 to the first evaporator 14a is weak, i.e., the heating of the first evaporator 14a is weak, and the defrosting time is likely to be long.

In addition, the temperature conditions inside the refrigerator vary greatly depending on the mode of the switching compartments (first switching compartment 5A, second switching compartment 6A), and the flow of natural convection also changes. In contrast, by performing F first defrosting, which turns on the first fan 9a, it is possible to generate a stable convection flowing from the defrost heater 21 to the first evaporator 14a at all times. Therefore, by performing F first defrosting, the first evaporator 14a can be heated using the heat of the air at refrigeration temperature, as in the first embodiment, and in the second embodiment, the effect of stabilizing the convection flowing from the defrost heater 21 to the first evaporator 14a is also obtained, which is more effective in improving energy-saving performance during defrosting.

Furthermore, in the refrigerator 1A of the second embodiment, the efficiency of defrosting other than the first evaporator 14a by the F-first defrost described in the first embodiment is more effectively improved. In addition, in the refrigerator 1A of the second embodiment, the first switching chamber 5A is provided almost in front of the first fan 9a, and the first switching chamber damper 201 that controls the airflow from the first fan 9a to the first switching chamber 5A is relatively close, and even if the first switching chamber damper 201 is closed, low-temperature air from the first evaporator 14a flows around the first switching chamber damper 201 when cooling the second switching chamber 6A. Here, when considering the case where the first switching chamber 5A is in the refrigeration mode, the first evaporator chamber 8a side is at a low temperature, so the first switching chamber damper 201 is likely to become low temperature, and the storage chamber side of the first switching chamber damper 201 is flowing with relatively high temperature and high humidity air in the refrigeration setting, so frost is likely to form on the first switching chamber damper 201. On the other hand, the first switching chamber damper 201 is farther from the defrost heater 21 than the first evaporator 14a, etc., and the heat of the defrost heater 21 does not reach the first switching chamber damper 201 sufficiently by natural convection. For this reason, a dedicated heater is generally used for the first switching chamber damper 201, but as in this embodiment, by performing the first defrosting by opening the first switching chamber damper 201 and turning on the first fan 9a, the heat of the defrost heater 21 can be easily reached around the first switching chamber damper 201. Therefore, the frost on the first switching chamber damper 201 can be efficiently melted by the heat of the defrost heater 21, and the dedicated heater for the first switching chamber damper 201 can be eliminated or the capacity of the heater can be reduced, which is effective in improving energy saving performance and reducing costs.

As in the second embodiment, by providing a damper capable of suppressing the airflow from the first evaporator 14a to all storage compartments (ice-making compartment 3, upper freezer compartment 4, first switching compartment 5A, second switching compartment 6A) cooled by the first evaporator 14a, it is also effective in suppressing overcooling caused by the intrusion of cold air into the switching compartments set to the refrigeration mode. Here, consider the refrigeration operation and the compressor 24 being stopped when the first switching compartment 5A is in the refrigeration mode and the freezer compartment damper 200 that controls the airflow to the ice-making compartment 3 and upper freezer compartment 4, which are storage compartments in the freezing temperature range. When the first fan 9a is driven with no refrigerant flowing through the first evaporator 14a, if the first switching compartment damper 201 is open, the air in the first switching compartment 5A circulates through the ice-making compartment 3 and upper freezer compartment 4, causing the temperatures of the ice-making compartment 3 and upper freezer compartment 4 to rise. Furthermore, even if the first switching compartment damper 201 is closed to allow air to flow only to the storage compartments in the freezing temperature range, the storage compartments cannot be effectively cooled because no refrigerant is flowing through the first evaporator 14a, and the power consumption of the first fan 9a is lost. Therefore, in general, the first fan 9a is not driven when the freezing compartment damper 200 is not provided. On the other hand, when the first fan 9a is stopped, the relatively low-temperature air around the first evaporator 14a descends by natural convection and returns to the first evaporator 14a via the freezing compartment return air duct 12c (see FIG. 10), the upper freezer compartment 4, the ice making compartment 3, and the first fan 9a, generating a convection current. At this time, the freezing compartment return air duct 12c is connected to the first switching compartment 5A via the first switching compartment return port 111b (see FIG. 11), so that the relatively low-temperature air flowing through the freezing compartment return air duct 12c flows in and out of the first switching compartment 5A, cooling the first switching compartment 5A in the refrigeration mode. As a result, for example, when the temperature around the refrigerator 1A is low, the first switching compartment 5A may be excessively cooled, and a heater may be used to heat the compartment to maintain the temperature, which may increase the amount of power consumed. On the other hand, as in the second embodiment, dampers capable of suppressing the airflow from the first evaporator 14a are provided for all storage compartments cooled by the first evaporator 14a, and by closing all of these dampers (freezer compartment damper 200, first switching compartment damper 201, second switching compartment damper 202), the air circulation flow path of the first evaporator 14a through the storage compartment is eliminated. Therefore, the flow of cold air from the first evaporator 14a to the first switching compartment 5A in the refrigeration temperature range due to natural convection is suppressed, and the power supply to the heater due to the low temperature can be suppressed, thereby improving the energy saving performance.

In addition, in the refrigerator 1A of the second embodiment, the partition member 20b (see FIG. 9) on the first evaporator chamber 8a side is made of expanded polystyrene, which has a low heat capacity and relatively high heat insulating performance, among the partition members between the first evaporator 14a and the first evaporator chamber 8a and the first switching chamber 5A and the second switching chamber 6A. As with the first embodiment, this partition member 20b has a low heat capacity, so that heat transfer from the first evaporator 14a and the first evaporator chamber 8a during F-off cycle operation is suppressed. In addition, in the second embodiment, which has a storage chamber (first switchable chamber 5A, second switchable chamber 6A) that can be set to the refrigeration temperature zone approximately in front of the first evaporator 14a and first evaporator chamber 8a, the partition member 20b can act as a heat insulating member between the low-temperature first evaporator 14a and first evaporator chamber 8a and the first switchable chamber 5A and second switchable chamber 6A in the refrigeration temperature zone, and is also effective in preventing excessive cooling of the first switchable chamber 5A and second switchable chamber 6A when set to the refrigeration temperature zone, and in preventing condensation in the first switchable chamber 5A and second switchable chamber 6A.

The present invention is not limited to the first and second embodiments described above, and includes various modified examples. For example, the above-mentioned embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those having all of the configurations described. In addition, it is possible to add, delete, or replace some of the configurations of the above-mentioned embodiments with other configurations. For example, although an example having a freezer compartment 7 and a vegetable compartment 6 as multiple first evaporator cooling compartments has been described, a configuration having multiple vegetable compartments may also be used. In addition, although an example having a refrigerator compartment 2 as one or more second evaporator cooling compartments has been described, a configuration having multiple refrigerator compartments may also be used. In addition, in the second embodiment, an example having multiple switching compartments, a first switching compartment 5A and a second switching compartment 6A, has been described, but a single switching compartment may also be used.

1, 1A Refrigerator 2 Refrigerator compartment (second evaporator cooling compartment)
3 Ice making room (first evaporator cooling room)
4. Upper freezer compartment (first evaporator cooling compartment)
5 Lower freezer compartment (first evaporator cooling compartment, freezer storage compartment)
5A First switching room (switching room)
5c First switching chamber container (switching chamber container)
6 Vegetable compartment (first evaporator cooling compartment, refrigerated storage compartment)
6A Second switching room (switching room)
6c Second switching chamber container (switching chamber container)
7 Freezer compartment (first evaporator cooling compartment)
8a First evaporator chamber 8b Second evaporator chamber 9a First fan 9b Second fan 14a First evaporator 14b Second evaporator 20b Partition member (foamed heat insulating material)
21 Defrost heater 24 Compressor 31 Control board (control unit)
40a First evaporator temperature sensor 40b Second evaporator temperature sensor 41 Refrigerator temperature sensor 42 Freezer temperature sensor 43 Vegetable compartment temperature sensor 50a External radiator (heat radiating section)
50b Wall surface heat radiation piping (heat radiation part)
50c Condensation prevention piping (heat dissipation section)
52 Three-way valve (refrigerant control means)
53a Refrigeration capillary tube (first pressure reduction section)
53b Refrigeration capillary tube (second pressure reduction section)
101 Freezer damper 102 Vegetable damper 200 Freezer damper 201 First switching compartment damper 202 Second switching compartment damper R1 First refrigerant flow path R2 Second refrigerant flow path

Claims (4)

a first refrigerant flow path through which a refrigerant flows in this order: a compressor, a heat radiating section, a refrigerant control means, a first pressure reducing section, and a first evaporator;
a second refrigerant flow path through which a refrigerant flows in this order: the compressor, the heat radiating section, the refrigerant control means, a second pressure reducing section, and a second evaporator;
A first fan that blows the air cooled by the first evaporator;
a plurality of first evaporator cooling chambers to which air is blown by the first fan;
A second fan that blows the air cooled by the second evaporator;
one or more second evaporator cooling chambers to which air is blown by the second fan;
Equipped with
The plurality of first evaporator cooling compartments each include one or more freezer storage compartments set to a freezing temperature zone and one or more refrigerated storage compartments set to a refrigeration temperature zone, and the refrigerator further includes a control unit that executes an operation to drive the first fan to blow air into the refrigerated storage compartments while suppressing air blowing from the first fan to all of the freezer storage compartments, and drive the second fan while flowing refrigerant through the second refrigerant flow path to cool the second evaporator cooling compartment . In the refrigerator according to claim 1 ,
A defrosting heater is provided to heat the first evaporator to melt frost,
The control unit suppresses the first fan from blowing air to all of the freezer storage compartments, while energizing the defrost heater and driving the first fan to blow air to the refrigerated storage compartments. In the refrigerator according to claim 1 or 2 ,
The refrigerator is characterized in that at least one of the freezer storage compartment and the refrigerated storage compartment is a switchable compartment capable of switching between a freezing temperature zone and a refrigerated temperature zone. The refrigerator according to claim 3 ,
A switching chamber container is provided in the switching chamber to store food,
The refrigerator is characterized in that air blown from the first fan is blown toward the inside of the switchable compartment container.

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