JP6890502B2 - refrigerator - Google Patents

Description

The present invention relates to a refrigerator.

The refrigerator described in Patent Document 1 (Japanese Patent No. 5854937) is described as "a refrigerating space, a refrigerating space, a compressor, and evaporation to cool the refrigerating space and the refrigerating space by supplying a refrigerant discharged from the compressor. A container, an evaporator fan that blows air cooled by the evaporator to the refrigerating space and the refrigerating space, and a refrigerating damper that opens and closes a flow path that supplies air cooled by the evaporator to the refrigerating space. A refrigerating damper that opens and closes a flow path that supplies air cooled by the evaporator to the refrigerating space, a defrost heater that heats frost adhering to the evaporator, the compressor, the evaporator fan, and the above. A refrigerating damper, the refrigerating damper, and a control unit for controlling the defrosting heater are provided, and the control unit stops the compressor, opens the refrigerating damper, closes the refrigerating damper, and sets the refrigerating damper in a closed state. The first defrosting operation is performed by driving the evaporator fan and energizing the defrosting heater so that at least a part of the evaporator maintains the melting temperature of the frost or less, and frost remains in the evaporator. The first defrosting operation is finished in this state, then the compressor is stopped, the refrigerating damper is opened, the refrigerating damper is closed, the evaporator fan is driven, and the defrosting is performed. The second defrosting operation in which the frost heater is de-energized is executed (see claim 1), and "when the temperature of the evaporator reaches the melting temperature of the frost during the execution of the first defrosting operation, the said "End the first defrosting operation and execute the second defrosting operation" (see claim 2), "The temperature of the evaporator reaches the melting temperature of the frost during the execution of the second defrosting operation." Then, the second defrosting operation is terminated ”(see claim 3).

Further, "the control unit ends the second defrosting operation when the temperature of the evaporator detected by the evaporator temperature sensor reaches a predetermined temperature (for example, 10 ° C.) after starting the fourth defrosting operation." (Refer to paragraph 0068 of Patent Document 1), "In the fourth defrosting operation, the control unit stops the compressor, closes the refrigerating damper and the refrigerating damper, stops the evaporator fan, and turns on the defrosting heater. "Energize state" (see paragraph 0067 of Patent Document 1).

Japanese Patent No. 5854937

The refrigerator of Patent Document 1 does not consider the frost adhering to the wall surface on the downstream side in the air flow direction with respect to the evaporator. The first defrosting operation is performed to drive the evaporator fan while energizing the defrosting heater within the range where the temperature of the evaporator is lower than the melting temperature of frost, and when the temperature of the evaporator reaches the melting temperature of frost, the defrosting heater is turned on. It is described that the second defrosting operation for de-energizing is performed. The outlet air that has passed through the evaporator becomes cold and has a temperature similar to that of the evaporator. Since the evaporator during the first defrosting operation and the second defrosting operation is below the melting temperature, the temperature of the outlet air passing through the evaporator is equal to or lower than the melting temperature of frost. Therefore, it is difficult to defrost the frost adhering to the wall surface on the downstream side in the air flow direction with respect to the evaporator during the first defrosting operation.

Further, in the second embodiment of Patent Document 1, the fourth defrosting operation in which the evaporator fan is stopped and the defrosting heater is energized is performed until the temperature of the evaporator exceeds the melting temperature (FIG. 1 of Patent Document 1). 6). However, in the fourth defrosting, since the evaporator fan is stopped, the flow velocity of air is low, and the wall surface on the downstream side of the evaporator is less likely to be heated. Therefore, in order to defrost the wall surface, it is necessary to lengthen the heating time by the defrost heater or increase the amount of heat generated, and there is a problem that the energy saving performance is lowered.

Therefore, an object of the present invention is to provide a refrigerator that performs a defrosting operation with high energy-saving performance while melting the frost adhering to the wall surface downstream of the evaporator.

In view of the above problems, the present invention has been made in view of the first storage chamber in the refrigerating temperature zone, the second storage chamber in the freezing temperature zone chamber, the compressor, the first storage chamber and the second storage chamber. An evaporator that cools the chamber, a fan that blows air cooled by the evaporator to the first storage chamber and the second storage chamber, and a fan that blows air from the evaporator to the first storage chamber. A refrigerator damper that controls the temperature of the refrigerator, a freezer damper that controls the air blown from the evaporator to the second storage chamber, a defrost heater that defrosts frost adhering to the evaporator, and the temperature of the evaporator. In a refrigerator provided with an evaporator temperature detecting means for detecting, a first defrosting mode in which the fan is stopped and the defrosting heater is energized while the compressor is stopped, and a state in which the freezer damper is closed. A second defrosting mode is provided in which the refrigerating chamber damper is opened, the fan is driven to energize the defrosting heater, and after the first defrosting mode is performed, the second defrosting mode is performed. A refrigerator characterized in that a frost mode is performed and the second defrost mode is performed until the evaporator temperature detecting means reaches a temperature higher than the melting temperature of frost.

According to the present invention, it is possible to provide a refrigerator that performs a defrosting operation with high energy-saving performance while melting the frost adhering to the wall surface downstream of the evaporator.

It is a front view of the refrigerator which concerns on Example. FIG. 1 is a sectional view taken along the line AA of FIG. It is a front view which shows the peripheral part of an evaporator. It is an enlarged view around the evaporator of FIG. 2 which shows the air flow in the defrost mode 1. It is an enlarged view around the evaporator of FIG. 2 which shows the air flow in a defrost mode 2. This is an example of a time chart showing defrost control.

Examples of the refrigerator according to the present invention will be described. FIG. 1 is a front view of the refrigerator according to the embodiment, and FIG. 2 is a sectional view taken along the line AA of FIG. The box body 10 of the refrigerator 1 has a refrigerating chamber 2 from above, an ice making chamber 3 attached to the left and right, an upper freezing chamber 4, a lower freezing chamber 5, and a vegetable compartment 6 in this order. Refrigerator 1 is provided with a door that opens and closes the opening of each storage room. These doors open and close the opening of the refrigerating room 2, the left and right rotating rotating refrigerating room doors 2a and 2b, and the opening of the ice making room 3, the upper freezing room 4, the lower freezing room 5, and the vegetable room 6. A pull-out type ice making chamber door 3a, an upper freezing chamber door 4a, a lower freezing chamber door 5a, and a vegetable compartment door 6a that open and close, respectively. Hereinafter, the ice making chamber 3, the upper freezing chamber 4, and the lower freezing chamber 5 are collectively referred to as a freezing chamber 7.

The door 2a is provided with an operation unit 26 for operating the temperature setting in the refrigerator. Door hinges (not shown) are provided at the upper and lower parts of the refrigerator compartment 2 to fix the refrigerator 1 and the doors 2a and 2b, and the upper door hinges are covered with the door hinge cover 16.

As shown in FIG. 2, the outside and inside of the refrigerator 1 are separated by a box body 10 formed by filling the outer box 10a and the inner box 10b with a foamed heat insulating material. In addition to the foam heat insulating material, a plurality of vacuum heat insulating materials 25 are mounted on the box body 10 between the outer box 10a made of steel plate and the inner box 10b made of synthetic resin. The refrigerating room 2, the upper freezing room 4, and the ice making room 3 are separated by a heat insulating partition wall 28, and similarly, the lower freezing room 5 and the vegetable room 6 are separated by a heat insulating partition wall 29. Further, on the front side of each storage chamber of the ice making chamber 3, the upper freezing chamber 4, and the lower freezing chamber 5, the air inside the freezing chamber 7 leaks to the outside of the refrigerator through the gaps between the doors 3a, 4a, and 5a, and the outside of the refrigerator. A heat insulating partition wall 30 is provided so that air does not enter each storage chamber.

A plurality of door pockets 33a, 33b, 33c and a plurality of shelves 34a, 34b, 34c, 34d are provided inside the doors 2a and 2b of the refrigerating chamber 2, and are partitioned into a plurality of storage spaces. In the freezing room 7 and the vegetable room 6, an ice making room container (not shown), an upper freezing room container 4b, a lower freezing room container 5b, and a vegetable room container 6b, which are pulled out integrally with the doors 3a, 4a, 5a, and 6a, respectively A storage chamber 35 is provided above the heat insulating partition wall 28 provided. In general, the storage room 35 is often provided with a chilled room set lower than the temperature range of the refrigerating room 2. The temperature inside the storage chamber 35 is adjusted by, for example, a dedicated air volume adjusting device (not shown) provided in the middle of the refrigerating chamber cold air duct 11 at the rear of the storage chamber 35, and the storage chamber 35 is too cold. Is heated by a temperature adjusting heater 19 provided in the lower part of the storage chamber 35.

The evaporator 14 is provided in the evaporator storage chamber 8 provided substantially behind the lower freezing chamber 5, and the cold air that has exchanged heat with the evaporator 14 by the internal fan 9 provided above the evaporator 14 is a refrigerating chamber. The air is sent from the discharge ports 11a and 12a to the storage chambers of the refrigerating chamber 2, the upper freezing chamber 4, the lower freezing chamber 5, and the ice making chamber 3 via the cold air duct 11 and the freezing chamber cold air duct 12, respectively. The blowing of cold air to the refrigerating chamber 2 and the freezing chamber 7 is controlled by opening and closing the refrigerating chamber damper 20 and the freezing chamber damper 21. In the evaporator storage chamber 8, the space below the evaporator 14 is referred to as an air passage 8a, and the space from the evaporator 14 to the refrigerating chamber damper 20 and the freezing chamber damper 21 is referred to as an air passage 8b.

The air passage 8a below the evaporator 14 is provided with, for example, a defrost heater 22 which is a radiant heater. The drain water (melted water) generated during defrosting once falls into the gutter 23 and is discharged to the evaporating dish 32 provided on the upper part of the compressor 24 through the drain hole 27.

A refrigerator room temperature sensor 41, a freezer room temperature sensor 42, and a vegetable room temperature sensor 43 are provided on the back side of the refrigerator chamber 2, the freezer chamber 7, and the vegetable compartment 6, respectively, and the evaporator temperature is above the evaporator 14. Sensors 40 are provided, and the temperatures of the refrigerator compartment 2, the freezer compartment 7, the vegetable compartment 6, and the evaporator 14 are detected by these sensors. Further, inside the door hinge cover 16 on the ceiling of the refrigerator 1, an outside air temperature sensor 37 for detecting the temperature and humidity of the outside air (outside air) is provided. Other sensors include a door sensor (not shown) that detects the open / closed state of the doors 2a, 2b, 3a, 4a, 5a, and 6a, a partition temperature sensor 100 that is a partition temperature detecting means described later, and the like. There is.

A control board 31 on which a CPU, a memory such as a ROM or RAM, an interface circuit, or the like, which is a part of the control device, is mounted is arranged on the upper part of the refrigerator 1. The control board 31 is connected to the refrigerating room temperature sensor 41, the freezing room temperature sensor 42, the vegetable room temperature sensor 43, the evaporator temperature sensor 40, and the like. Based on a program or the like recorded in advance in the ROM of the above, the compressor 24, the internal fan 9, the refrigerator compartment damper 20, the freezer compartment damper 21, and the refrigerant control valve 47 described later are controlled.

In the case of the refrigerating room cooling operation for cooling the refrigerating room 2, the refrigerating room damper 20 is opened, the freezing room damper 21 is closed, and cold air is sent from the discharge port 11a provided in the refrigerating room cold air duct 11 to the refrigerating room 2. Be done. After cooling the refrigerating chamber 2, the cold air flows into the refrigerating chamber return duct 51 shown in FIG. 3 from the cold air return port (not shown) provided in the lower part of the refrigerating chamber 2, and then returns to the evaporator 14.

In the case of the freezing room cooling operation for cooling the freezing room 7, the refrigerating room damper 20 is closed, the freezing room damper 21 is opened, and cold air is discharged from a plurality of discharge ports 12a provided in the freezing room cold air duct 12. After cooling the upper freezing chamber 4, the lower freezing chamber 5, and the ice making chamber 3, the refrigerator returns to the evaporator 14 from the freezing chamber cold air return unit 17.

The temperatures of the refrigerating chamber 2 and the freezing chamber 7 are detected by the refrigerating chamber temperature sensor 41 and the freezing chamber temperature sensor 42 provided in the refrigerator, and the refrigerating chamber 2 and the freezing chamber 7 are simultaneously cooled according to the temperature inside the refrigerator. In that case, both the refrigerator compartment damper 20 and the freezer compartment damper 21 are opened to blow cold air to each storage chamber.

There are various methods for cooling the vegetable compartment 6. For example, a method of cooling the refrigerating chamber 2 and then sending cold air to the vegetable compartment 6 or an air volume adjusting device (not shown) dedicated to the vegetable compartment 6 is used. , There is a method of directly sending the cold air generated by heat exchange in the evaporator 14 to the vegetable compartment 6. In this embodiment, the method of supplying cold air to the vegetable compartment 6 may be any case. In the description example of FIG. 2, the cold air flowing into the vegetable compartment 6 is sent from the cold air return portion 18a on the vegetable compartment side provided in front of the lower part of the heat insulating partition wall 29 to the vegetable chamber cold air return portion 18 via the vegetable chamber cold air return duct 18. It flows from 18b to the lower part of the evaporator 14.

FIG. 3 is a view of the peripheral portion of the evaporator 14 according to the embodiment of the present invention as viewed from the front of the refrigerator. The refrigerant pipe 50 connected to the evaporator inlet pipe 47 and the evaporator outlet pipe 48 is folded back in the vertical direction to form a seven-stage fin tube heat exchanger (evaporator 14). An evaporator temperature sensor 40 is installed in the evaporator inlet pipe 47 provided above the evaporator 14, and a determination regarding the defrosting operation is performed based on the temperature detected by the evaporator temperature sensor 40. The defrosting heater 22 provided in the lower part of the evaporator 14 has a glass tube 44 in which a heater wire is inserted, a metal heat radiating fin 46 provided in the outer peripheral portion thereof, and an upper part of the glass tube 44 and the metal fin 46. It is composed of a metal molten water dripping prevention portion 45 provided so as to cover it. The refrigerator 1 of the present embodiment uses a flammable refrigerant, and the defrost heater 22 makes the surface temperature of the glass tube 44 combustible while the power is on, assuming that the flammable refrigerant leaks in the refrigerator. The temperature is maintained at 100 ° C. or higher lower than the ignition temperature of the sex refrigerant (494 ° C. in the case of isobutane). By providing the molten water dripping prevention portion 45 on the upper part of the glass tube 44, the molten water generated during defrosting is directly dropped on the surface of the glass tube 44 to prevent the glass tube 44 from being damaged due to a sudden temperature change. There is. Considering the ventilation resistance of the circulating air in the refrigerator, the melted water dripping prevention portion 45 is preferably about the same diameter as the heat radiation fin 46. The output of the defrost heater 22 is generally an electric heater of 100 W to 200 W, and is set to 150 W in the example of the present embodiment.

A refrigerating chamber cold air return duct 51 is provided on the side of the evaporator 14, and when the refrigerating chamber damper 20 is opened, the freezing chamber damper 21 is closed, and the internal fan 9a is driven, the refrigerating chamber 2 is cooled. Air flows in from the refrigerating chamber return duct 51. The air flowing into the refrigerating chamber return duct 51 turns to the evaporator 14 side in the air passage 8a, passes through the gutter 23 and the defrost heater 22, and passes from the bottom (7th) to the top (7th) of the evaporator 14. Heading toward the first stage), it flows to the refrigerator fan 9 via the air passage 8b.

Next, the defrosting operation of the present embodiment will be described. The refrigerator 1 of the embodiment is provided with two defrosting operations, a defrosting mode 1 and a defrosting mode 2. The defrosting mode 1 is a defrosting operation in which the defrosting heater 22 is energized (ON) with the internal fan 9 stopped (OFF).

FIG. 4a is an enlarged view of the periphery of the evaporator of FIG. 2 showing the air flow in the defrosting mode 1. The defrosting mode 1 is a mode in which the defrosting heater 22 is energized (ON) with the refrigerator compartment damper 20 closed, the freezing chamber damper 21 opened, and the internal fan 9 stopped (OFF). Since the internal fan 9 is stopped, the evaporator 14 is mainly heated by natural convection. The air in the air passage 8a under the evaporator 14 heated by the defrost heater 22 rises due to natural convection. The evaporator 14 is heated by heat exchange between the heated air and the evaporator 14. After heating the evaporator 14, air flows out from the discharge port 12a to the freezing chamber 7 via the freezing chamber damper 21. On the other hand, the air in the freezing chamber 7 flows from the freezing chamber return port 17 to the air passage 8a.

In this way, even in the defrosting mode 1 in which the internal fan 9 is stopped, air circulates due to convection and heats the evaporator 14, but the flow velocity of the air flowing from the defrosting heater 22 to the evaporator 14 is high. Since it is low, the influence of radiation is large, and the defrosting mode 1 is a defrosting mode in which the periphery of the defrosting heater 22, particularly the wall surface in contact with the air passage 8a such as the toy 23, and the lower part of the evaporator 14 are easily heated.

The reason why the freezer damper 21 is open is that the above-mentioned air circulation is formed and the natural convection of air from the defrost heater 22 to the evaporator 14 is promoted. As a result, the amount of heat for the evaporator 14 can be increased as compared with the case where the freezer damper 21 is closed, and the amount of heat for the wall surface of the air passage 8b downstream of the evaporator 14 can also be increased.

FIG. 4b is an enlarged view of the periphery of the evaporator of FIG. 2 showing the air flow in the defrosting mode 2. The defrosting mode 2 is a mode in which the refrigerating chamber damper 20 is opened, the freezing chamber damper 21 is closed, and the defrosting heater 22 is energized (ON) while the internal fan 9 is driven (ON). Since the refrigerator compartment damper 20 is opened, the freezer compartment damper 21 is closed, and the internal fan 9 is driven, the inside of the evaporator chamber 8 becomes a flow field similar to the flow shown in FIG. That is, the air in the refrigerating chamber 2 flows into the air passage 8a from the refrigerating chamber return duct 51 (see FIG. 3), is heated by the defrost heater 22, and then reaches the evaporator 14 to heat the evaporator 14. After heating the evaporator 14, the air is boosted by the internal fan 9a and flows to the refrigerating chamber 2 via the refrigerating chamber damper 20 and the refrigerating chamber cold air duct 11.

That is, in the defrost mode 2, since it becomes a flow field of forced convection, the amount of heat generated by convection increases, and compared to the defrost mode 1, the upper part of the defrost heater 22, especially the evaporator 14, and the wall surface around the fan 100, etc. This is a defrosting mode in which the wall surface in contact with the air passage 8b can be easily heated.

FIG. 5 is an example of a time chart showing defrost control. The evaporator temperature is the temperature of the evaporator 14 detected by the evaporator temperature sensor 40, the refrigerating chamber temperature is the temperature of the refrigerating chamber 2 detected by the refrigerating chamber temperature sensor 41, and the wall surface temperature around the fan is the wall surface around the fan. The temperature and toy temperature of a fan peripheral wall surface 100 (see FIGS. 4a and 4b) are the wall surface temperature of the toy 23. 1 and 2 shown in FIG. 5 represent defrost mode 1 and defrost mode 2. Further, ON of the compressor 24 and the fan 9 in the refrigerator represents a driving state, and OFF represents a stopped state.

In the example of the present embodiment, for example, the conditions for starting the defrosting operation determined from the number of times the doors 2a, 3a, 4a, 5a, and 6a are opened and closed, the total driving time of the compressor 24, and the like are satisfied (time t ₀ ). , The refrigerator 1 of the embodiment of the present embodiment performs a pre-cool operation.

If the temperature of the freezing chamber 7 rises excessively during the defrosting operation, there is a risk of melting frozen foods and ice. On the other hand, in the example of the present embodiment, the refrigerating chamber 2 can be cooled even during the defrosting operation. The refrigerating chamber damper 20 is closed, the freezing chamber damper 21 is opened, and the freezing chamber 3 is cooled. After performing the pre-cool operation for a predetermined time, for example, 30 minutes (time t ₁ ), the refrigerator 1 of the present embodiment shifts to the defrosting operation.

The refrigerator 1 of the embodiment is provided with two types of defrosting operations, a defrosting mode 1 and a defrosting mode 2, and the defrosting mode 1 is first performed. As shown in FIG. 4a, the defrosting mode 1 is a mode in which the defrosting heater 22 is energized (ON) with the internal fan 9 stopped (OFF), and is mainly around the defrosting heater 22. In particular, it heats the wall surface of the toy 23 or the like forming the air passage 8a below the evaporator 14.

The defrosting mode 1, after for example 10 minutes (time t _2), the process proceeds to defrosting mode 2. As shown in FIG. 4b, the defrosting mode 2 is a mode in which the refrigerating chamber damper 20 is opened, the freezing chamber damper 21 is closed, and the defrosting heater 22 is energized while driving the internal fan 9. Above the defrost heater 22, in particular, the evaporator 14 and the wall surface forming the air passage 8b such as the fan peripheral wall surface 100 are heated.

After that, when the temperature of the evaporator 14 _{reaches the defrosting end temperature T fin} (for example, 10 ° C.) _{sufficiently higher than the melting temperature of the frost (time t 4} ), the defrosting operation is terminated.

If the temperature of the evaporator 14 is _{higher than the predetermined temperature T 2 fin} (for example, 5 ° C.) and higher than the temperature of the refrigerating chamber 2 by the predetermined temperature (for example, 3 ° C.) _{before reaching the temperature T fin,} The mode shifts to the defrosting mode 1, and the defrosting is performed in the defrosting mode 1 up to the _{defrosting end temperature T fin.} As a result, it is possible to suppress heating of the refrigerating chamber 2 by the air that has passed through the evaporator 14.

After defrosting operation ends (time t ₄₎ is such that the defrost water is discharged, for example to drive the compressor 24 after the defrosting completion 2 minutes. Then, for example, 2 minutes after driving the compressor 24, the refrigerating chamber damper 21 is opened, the freezing chamber damper 20 is closed and the internal fan 9 is driven. For example, 10 minutes later, the freezing chamber damper 20 is opened and refrigerated. The operation shifts to cooling the chamber 2 and the freezing chamber 7. By delaying the drive of the internal fan 9 and the opening time of the refrigerator compartment damper 21 and the freezer compartment damper 20 with respect to the compressor 24, the evaporator 14 is cooled to a low temperature and then blown air. , The heating of the freezer chamber 7 can be suppressed.

The above is the control of the basic defrosting operation in the refrigerator 1 of the present embodiment. Next, the effect obtained by the main defrosting operation, particularly the defrosting mode 2 in which the refrigerating chamber damper 20 is opened, the freezing chamber damper 21 is closed, and the defrosting heater 22 is energized while driving the internal fan 9, will be described. To go.

In the defrosting mode 2, the flow field is forced convection, so that the flow velocity flowing through the evaporator chamber 8 is faster than that in the defrosting mode 1. As the flow velocity increases, the amount of heat exchanged between the defrost heater 22 and air increases, the proportion of heat generated by radiation decreases, and the proportion of heat generated by convection to the evaporator 14 and the like (heat amount via air) increases. To increase. In addition, as the flow velocity increases, the heat transfer coefficient increases, so that the amount of heat transferred from the air to the wall surface (including the evaporator 14) also increases. Therefore, in the defrosting mode 2 as compared with the defrosting mode 1, the amount of heat applied to the wall surface forming the evaporator 14 and the air passage 8b located on the downstream side (upper side) of the defrosting heater 22 which is mainly heated by convection is increased. Can be enhanced. As a result, the frost adhering to the evaporator 14 can be thawed in a short time, and the power consumption required for the defrosting operation can be reduced.

Further, in general, when the flow velocity is high, the temperature distribution of air becomes small, so that overheating of the lower part of the evaporator 14 near the defrost heater 22 is suppressed as compared with the case of defrosting only in the defrost mode 1, and after the defrost operation. It is possible to reduce the heat load that drives and cools the compressor 24. _{In addition, from time t 2} to t ₃ when the temperature of the evaporator 14 is lower than the temperature of the refrigerating chamber 2, air lower than that of the refrigerating chamber 2 flows into the refrigerating chamber 2 to cool the refrigerating chamber 2. The heat load of the refrigerating chamber 2 that drives and cools the compressor 24 can also be reduced. Therefore, the power consumption required for the cooling operation can also be reduced.

As described above, by providing the defrosting mode 2, the power consumption of both the defrosting operation and the cooling operation can be reduced, and the energy saving performance can be improved.

Further, in the refrigerator 1 of the present embodiment, the _{defrosting mode 2 is performed at least up to T 2 fin} higher than the melting temperature of frost, whereby the wall surface forming the air passage 8b, particularly the wall surface around the fan 100 (FIG. 4a). , FIG. 4b) is efficiently thawed to melt the frost adhering to the wall surface in contact with the air passage 8b downstream of the evaporator 14, while improving the energy saving performance. The reason for this will be explained below.

During the defrosting operation, the air flowing through the air passage 8b above the evaporator 14 (downstream in the air flow direction away from the defrost heater 22) is cooled by exchanging heat with the frost adhering to the evaporator 14 and the evaporator 14. , The temperature is about the same as the temperature of the upper part of the evaporator 14. Therefore, when the temperature of the evaporator 14 is equal to or lower than the frost melting temperature (0 ° C.), the air flowing through the air passage 8b is basically also equal to or lower than the frost melting temperature. In order to defrost the frost adhering to the wall surface by heating by convection, it is necessary to exchange heat with air having a temperature higher than the melting temperature of the frost. The wall surface forming the air passage 8b has an evaporator 14 between it and the defrost heater 22, and the amount of heat generated by radiation is small. Therefore, the frost on the wall surface in contact with the air passage 8b including the fan peripheral wall surface 100 cannot be basically thawed until the air temperature passing through the evaporator 14 becomes higher than the melting temperature of the frost, but the temperature of the evaporator 14 is frost. By performing the defrosting operation until T 2 fin is higher than the melting temperature of frost, the frost on the wall surface in contact with the air _{passage 8b can be defrosted by the air higher than the melting temperature of the frost.}

_{Further, by setting the} defrost mode 2 up to T 2 fin, which is higher than the melting temperature of frost, the heat transfer coefficient is higher than that of the defrost mode 1, and the amount of heat from the air to the wall surface increases. Therefore, the frost adhering to the wall surface can be efficiently heated by the air having a temperature higher than the melting temperature of the frost, so that the frost adhering to the wall surface can be reliably defrosted in a short time. That is, the time of the defrosting operation can be shortened while melting the frost adhering to the wall surface in contact with the air passage 8b, particularly the wall surface 100 around the fan, and the defrosting operation has high energy saving performance.

Next, as shown in FIG. 5, the effect of performing the defrosting operation in the order of the defrosting mode 1 and the defrosting mode 2 will be described.

As described above with reference to FIG. 4a, the defrosting mode 1 is close to the defrosting heater 22, and easily heats the lower part of the evaporator 14 and the toy 23. Since the defrosted water is discharged from the toy 23 via the drain pipe 24, the toy 23 is heated in the first half of the defrosting operation to keep the water freezing temperature (0 ° C.) or higher, so that the toy is sent from the evaporator 14 or the like. The defrosted water that has reached 23 can be discharged to the drain pipe 24 without refreezing. The air temperature of the air passage 8b does not exceed the melting temperature of the frost until the temperature of the evaporator 14 exceeds the melting temperature of the frost, but the air in the air passage 8a located on the upstream side of the evaporator 14 is used for defrosting operation. Since the defrost heater 22 can heat the toy 23 to a temperature higher than the melting temperature of the frost from the initial stage, the toy 23 can be sufficiently heated to 0 ° C. or higher even in the first half of the defrosting operation in which the temperature of the evaporator 14 is low.

Further, since high humidity air flows into the evaporator 14 from the upstream side during the cooling operation and frost is formed, the amount of frost formed in the lower part of the evaporator 14 on the upstream side is likely to be larger than that on the downstream side. .. Therefore, the defrosting mode 1 that easily heats the lower part of the evaporator 14 is performed in the first half of the defrosting operation, and the lower part of the evaporator 14 having a large amount of frost is intensively heated to efficiently defrost the lower part of the evaporator 14. It can be heated, and then the entire evaporator 14 can be heated in the defrosting mode 2 having a small temperature distribution, so that the frost can be efficiently defrosted as a whole.

Further, as described above, the frost on the wall surface in contact with the air passage 8b cannot be thawed until the temperature of the air passing through the evaporator 14 exceeds the melting temperature of the frost. I'm going in the second half. That is, in the latter half of the defrosting operation in which the air temperature of the air passage 8b becomes higher than the melting temperature of the frost, the defrost mode 2 is performed in which the wall surface in contact with the air passage 8b is easier to heat than the defrost mode 1. The frost adhering to the wall surface in contact with the air passage 8b, particularly the wall surface around the fan 100, can be efficiently melted.

As described above, by performing the defrosting mode 1 and the defrosting mode 2 in this order, the wall surface in contact with the air passage 8a on the upstream side of the evaporator 14, the wall surface in contact with the air passage 8b on the downstream side of the evaporator 14, and the evaporation. Appropriate heating can be performed for each of the heating of the vessel 14 itself. Therefore, the time of the defrosting operation can be shortened while melting the frost on the wall surface in contact with the evaporator 14 and the air passage 8b and discharging the defrosting water from the toy 23 to the drain pipe 24, resulting in energy saving performance. High defrosting operation.

Here, as shown in FIG. 4a, in the example of the present embodiment, the freezing chamber damper 21 is opened in the defrosting mode 1, the natural convection of air from the defrosting heater 22 to the evaporator 14 is promoted, and the evaporator. The amount of heating to 14 mag is increased.

On the other hand, both the refrigerator compartment damper 20 and the freezer compartment damper 21 can be closed. In this case, the time for transitioning from the defrosting mode 1 to the defrosting mode 2 may be shorter than that in the case of the present embodiment. When both the refrigerator compartment damper 20 and the freezer compartment damper 21 are closed, the updraft from the defrost heater 22 is suppressed, so that the amount of heat to the wall surface of the toy 23 or the like around the defrost heater 22 can be increased. Therefore, the heating amount of the evaporator 14 in the defrosting mode 1 is reduced, but the temperature of the toy 23 can be raised in a short time. Therefore, the evaporator 14 is shifted to the defrosting mode 2 which can be heated with high efficiency in a short time, and the wall surface in contact with the air passage 8a on the upstream side of the evaporator 14 is intensively heated in the relatively short defrosting mode 1. By mainly heating the wall surface in contact with the air passage 8b on the downstream side of the evaporator 14 and the evaporator 14 itself in the relatively long defrosting mode 2, the evaporator 14 and the evaporator 14 are similar to the refrigerator 1 of the present embodiment. The wall surface in contact with any of the air passages 8a and 8b can be appropriately heated, resulting in a defrosting operation with high energy-saving performance.

The above is an example showing the embodiment of the present embodiment. The present invention is not limited to the above-described examples, and includes various modifications. For example, the above-described examples have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. Further, it is possible to add / delete / replace a part of the configuration of the embodiment with another configuration.

1 Refrigerator 2 Refrigerator room (storage room in refrigerating temperature range)
2a, 2b Refrigerator door 3 Ice making room 3a Ice making room door 4 Upper freezing room 4a Upper freezing room door 4b Upper freezing room container 5 Lower freezing room 5a Lower freezing room door 5b Lower freezing room container 6 Vegetable room 6a Vegetable room door 6b Vegetables Room container 7 Freezing room (storage room in the freezing temperature range)
8 Evaporator storage room 8a, 8b, 8c Air passage 9 Interior fan 10 Insulation box body 10a Outer box 10b Inner box 11 Refrigerator room cold air duct 11a, 11b, 11c, 11d Refrigerator room cold air discharge port 12 Upper freezer room cold air duct 12a , 12b, 12c Discharge port 14 Evaporator 16 Door hinge cover 17 Freezer room cold air return part 18 Vegetable room cold air return duct 18a Cold air return part on the vegetable room side 18b Vegetable room cold air return part 19 Heater 20 Refrigerator room damper 21 Freezer room damper 22 Frost heater 23 Hi 24 Compressor 25 Vacuum insulation 26 Operation unit 27 Drain holes 28, 29 Insulation partition wall 30 Insulation partition wall 31 Control board 32 Evaporation tray 33a, 33b, 33c Door pocket 34a, 34b, 34c, 34d Shelf 35 Storage Chambers 36a, 36b, 36c Partition cover 37 Outside temperature sensor 38 Outside humidity sensor 39 Machine room 40 Evaporator temperature sensor (evaporator temperature)
41 Refrigerator room temperature sensor (refrigerator room temperature)
42 Freezer room temperature sensor 43 Vegetable room temperature sensor 44 Glass tube 45 Melted water dripping prevention part 46 Heat dissipation fin 47 Evaporator inlet pipe 48 Evaporator outlet pipe 50 Refrigerant pipe 100 Fan peripheral wall surface

Claims (1)

A first storage chamber in the refrigerating temperature zone, a second storage chamber in the freezing temperature zone chamber, a compressor, an evaporator for cooling the first storage chamber and the second storage chamber, and the evaporator. A fan that blows air cooled by the above to the first storage chamber and the second storage chamber, a refrigerator chamber damper that controls the blowing of air from the evaporator to the first storage chamber, and the evaporator. In a refrigerator provided with a freezer damper that controls blowing air from the second storage chamber to the second storage chamber, a defrost heater that defrosts frost adhering to the evaporator, and an evaporator temperature detecting means that detects the temperature of the evaporator. ,
While the compressor is stopped, the fan is stopped, the defrost heater is energized, the first defrost mode is set, the freezer damper is closed, and the refrigerator damper is open. The second defrosting mode is provided, and the second defrosting mode is performed after the first defrosting mode is performed to drive the defrosting heater to energize the defrosting heater. the evaporator temperature detecting means is had rows until the temperature higher than the melting temperature of the frost,
A refrigerator that opens the freezer damper during the execution of the first defrosting mode.

Images