TWI642884B - Refrigerator - Google Patents

Abstract

The refrigerator performs the operation described later: in the first defrosting operation, the heater is heated by the heater in the first frosting state in which the frost amount of the cooler is large; and the second defrosting operation is performed in the cooler. In the second frosting state, the cooler is heated by the heater; the second capacity of the heating capacity of the heater during the second defrosting operation is lower than the first heating capacity of the heater as the first defrosting operation capacity.

Description

 Refrigerator  

This invention relates to refrigerators, and more particularly to techniques for removing frost attached to a cooler.

The refrigerator includes a storage room, an air passage that communicates with the storage chamber, and a cooler that is installed in the air passage. Further, the refrigerator cools the air flowing from the storage chamber into the air passage by the cooler, and then flows the cooled air back to the storage chamber, thereby cooling the food or the like in the storage compartment. Here, when the door piece of the storage compartment is opened and closed in order to insert or take out food or the like, humid air outside the refrigerator flows into the storage compartment. In addition, water vapor is also generated in foods and the like stored in the storage room. Therefore, as the operation of the refrigerator continues, the water vapor contained in the air returning from the storage compartment becomes frost and adheres to the cooler.

Therefore, in the past, there has been proposed a refrigerator having a heater that heats a cooler, and the heater is used to heat the cooler to perform a defrosting operation of the cooler. For example, Patent Document 1 discloses a refrigerator which performs a defrosting operation under the premise of reducing power consumption, which is to install a temperature detecting component of two systems to a cooler, and judge the actual knot from the temperature difference thereof. The frost state controls the defrosting interval between the previous defrosting operation and the current defrosting operation.

Advanced technical literature

[Patent Document] Patent Document 1: JP-A-2001-215077

In the refrigerator described in Patent Document 1, when the defrosting operation is performed, the heating capacity [W] (in other words, the power consumption) of the heater is fixed irrespective of the amount of frost formed by the cooler. Therefore, the refrigerator described in Patent Document 1 has a problem as will be described later.

The cooler first starts to frost from the air containing steam that is returned from the storage chamber to the air inlet of the cooler (in other words, the upstream side of the air flow in the cooler). Thereafter, the frosting range of the cooler expands from the air inflow opening toward the air discharge port. And, finally, the entire cooler will be frosted. In other words, in the stage where the frost amount of the cooler is small, the amount of frost formed on the air discharge port side of the cooler is smaller than the amount of frost on the air inlet side of the cooler. Therefore, in the refrigerator described in Patent Document 1 in which the heating capacity of the heater is constant regardless of the amount of frosting, when the cooler of the stage where the amount of frost is small is defrosted, the heating capacity of the heater is relative to The amount of frost of the cooler is excessively large, and when the defrosting of the air inlet side of the cooler ends, the temperature of the air discharge port side of the chiller that has completed the defrosting is excessively increased. Therefore, the refrigerator described in Patent Document 1 has a problem that, after the defrosting of the cooler at the stage where the amount of frost formation is small, and the normal operation is resumed, the air supplied to the storage compartment is in the air discharge of the cooler. The outlet side is heated to raise the temperature inside the storage compartment. Further, the refrigerator described in Patent Document 1 has a problem in that it is necessary to consume electric power to increase the power consumption in order to cool the air in the storage compartment where the temperature has risen.

In order to solve the above problem, it is thought to reduce the heating capacity of the heater. However, in the refrigerator described in Patent Document 1 in which the heating capacity of the heater is constant regardless of the amount of frost, the cooler of the amount of frost is required to be defrosted. When it will lengthen the defrost time. That is, the cooled air cannot be supplied to the storage compartment for a long time. Therefore, in the refrigerator described in Patent Document 1, even if the heating capacity of the heater is made small, there is a problem that the temperature in the storage compartment rises. Further, the refrigerator described in Patent Document 1 has a problem in that it is necessary to consume electric power to increase the power consumption in order to reheat the air in the storage compartment where the temperature has risen.

In order to solve the above problems, an object of the present invention is to provide a refrigerator capable of controlling a temperature increase in a storage compartment due to a defrosting operation.

The refrigerator of the present invention includes: a storage compartment; an air passage communicating with the storage compartment; a cooler disposed on the air passage to cool air flowing in the air passage; and a heater that heats the cooler and In the first frosting state in which the frost is formed on the cooler, the heating capacity is the first capacity, and the heating capacity is the second capacity in the second frosting state in which the frosting of the cooler is less than the first frosting state. a first temperature sensor that detects a temperature of the cooler; wherein the heater heats the cooler by the second capacity when a detected value of the first temperature sensor is greater than a fourth determination value When the detection value of the first temperature sensor is equal to or lower than the fourth determination value, the cooler is heated by the first capacity; and the second capacity is smaller than the first capacity.

In the refrigerator of the present invention, in the first frosting state in which the frost amount of the cooler is large, the heating capacity of the heater can be increased to perform the defrosting operation. Therefore, in the refrigerator of the present invention, it is possible to suppress a case where the defrosting time becomes long when the cooler having a large amount of frost is to be defrosted, and it is possible to suppress an increase in the temperature in the storage chamber. Further, in the refrigerator of the present invention, in the second frosting state in which the amount of frost in the cooler is small, the heating capacity of the heater is lower than the heating capacity in the first frosting state to perform the defrosting operation. Therefore, in the refrigerator of the present invention, it is possible to suppress the temperature of the air discharge port side of the cooler from rising when the amount of frost is small to be defrosted. In other words, in the refrigerator of the present invention, when the cooler having a small amount of frost is to be defrosted, the temperature rise in the storage compartment can be suppressed.

1‧‧‧ frame

1a‧‧‧ inner box

1b‧‧‧outer box

2‧‧‧ machine room

3‧‧‧ Wind Road

4‧‧‧ blowing out the wind

5‧‧‧ blowing out the wind

6‧‧‧ blowing out the wind

7‧‧‧ return air path

8‧‧‧ return air path

9a‧‧‧wind file

9b‧‧‧wind file

10‧‧‧fan

11‧‧‧radiation heater

12‧‧‧Contact heater

21‧‧‧Refrigerator

22‧‧‧Freezer

23‧‧‧ Fruit and Vegetable Room

24‧‧‧ Doors

25‧‧‧ Doors

26‧‧‧ Doors

31‧‧‧ Temperature Sensor

32‧‧‧Temperature Sensor

33‧‧‧Temperature Sensor

34‧‧‧Temperature Sensor

35‧‧‧door opening and closing sensor

36‧‧‧Input current detection sensor

37‧‧‧Humidity sensor

38‧‧‧temperature sensor

50‧‧‧Refrigeration cycle

51‧‧‧Compressor

52‧‧‧ radiator

53‧‧‧Reducing device

54‧‧‧cooler

60‧‧‧Control device

61‧‧‧Control Department

62‧‧‧Determining Department

63‧‧‧Timekeeping Department

64‧‧‧Memory Department

70‧‧‧ Circuitry

71‧‧‧Power supply

72‧‧‧1st wiring department

73‧‧‧2nd wiring department

74‧‧‧resist

75‧‧‧ switch

76‧‧‧1st power supply

77‧‧‧2nd power supply

100‧‧‧ refrigerator

Fig. 1 is a side longitudinal sectional view showing an example of a refrigerator in accordance with a first embodiment of the present invention.

Fig. 2 is a view showing an example of a circuit of a refrigerator in the first embodiment of the present invention.

Fig. 3 is a view showing an example of a circuit of the refrigerator in the first embodiment of the present invention.

Fig. 4 is a perspective view showing the inside of the air passage of the refrigerator in the first embodiment of the present invention.

Fig. 5 is a view showing changes in temperature of the cooler when the cooler is defrosted in a state where the amount of frost is small in the conventional method.

Fig. 6 is a view showing changes in temperature of the cooler when the cooler in the state in which the amount of frost is small is defrosted in the refrigerator according to the first embodiment of the present invention.

Fig. 7 is a view showing another example of the defrosting operation in a state in which the amount of frost formation is small in the refrigerator according to the first embodiment of the present invention.

Fig. 8 is a view showing a temperature change of a cooler when a radiant heater is energized in the refrigerator in the first embodiment of the present invention.

Fig. 9 is a flowchart showing an example of a method of determining the frost amount of the cooler in the refrigerator in the first embodiment of the present invention.

Fig. 10 is a view showing the relationship between the operation time from the end of the defrosting operation and the frosting amount of the cooler in the refrigerator in the first embodiment of the present invention.

Fig. 11 is a view showing the relationship between the number of opening and closing of the door piece and the amount of frost formed by the cooler in the refrigerator according to the first embodiment of the present invention.

Fig. 12 is a side longitudinal sectional view showing an example of the refrigerator in the first embodiment of the present invention.

Fig. 13 is a flow chart showing an example of a method of determining the frost amount of the cooler in the refrigerator in the first embodiment of the present invention.

Fig. 14 is a view showing the P-Q characteristics (air volume-static pressure characteristics) of the fan of the refrigerator in the first embodiment of the present invention.

Fig. 15 is a side longitudinal sectional view showing an example of the refrigerator in the first embodiment of the present invention.

Fig. 16 is a flowchart showing an example of a method of determining the frost amount of the cooler in the refrigerator in the first embodiment of the present invention.

Fig. 17 is a flowchart showing an example of a method of determining the frost amount of the cooler in the refrigerator in the first embodiment of the present invention.

Fig. 18 is a view showing the relationship between the humidity in the storage room and the frosting amount of the cooler in the refrigerator in the first embodiment of the present invention.

Fig. 19 is a side longitudinal sectional view showing an example of the refrigerator in the first embodiment of the present invention.

Fig. 20 is a flowchart showing an example of a method of determining the frost amount of the cooler in the refrigerator in the first embodiment of the present invention.

Figure 21 is a side longitudinal sectional view showing an example of a refrigerator in a second embodiment of the present invention.

Fig. 22 is a perspective view showing the inside of the air passage of the refrigerator in the second embodiment of the present invention.

Fig. 23 is a flow chart showing an example of a method of determining the frost amount of the cooler in the refrigerator in the second embodiment of the present invention.

Fig. 24 is a view showing the relationship between the method of determining the amount of frost formation and the amount of heating of the heater shown in the first embodiment and the second embodiment.

Fig. 25 is a view showing an example of the relationship between the method of determining the amount of frost formation and the amount of heating of the heater of the present invention.

Fig. 26 is a view showing an example of the relationship between the method of determining the amount of frost formation and the amount of heating of the heater of the present invention.

Embodiment 1

Fig. 1 is a side longitudinal sectional view showing an example of a refrigerator in accordance with a first embodiment of the present invention. In addition, the first drawing and the side longitudinal cross-sectional view which will be described later show the refrigerator 100 in the front side of the refrigerator 100 as the left side.

The refrigerator 100 according to the first embodiment includes a storage compartment, an air passage 3 that communicates with the storage compartment, a cooler 54 that is provided in the air passage 3, and a radiant heater 11 that heats the cooler 54 during the defrosting operation.

The storage compartment and the air passage 3 are formed in the casing 1. The casing 1 is composed of a heat insulating material or the like provided between the inner box 1a, the outer box 1b, the inner box 1a, and the outer box 1b. The casing 1 is formed in a box shape having an open front side, and the inside of the inner casing 1a in the casing 1 is a storage compartment. In the first embodiment, the inside of the inner box 1a is partitioned by a partition plate to form a plurality of storage chambers. More specifically, as shown in Fig. 1, the refrigerator 100 of the first embodiment has a refrigerating compartment 21, a freezing compartment 22, and a fruit and vegetable compartment 23 as a storage compartment.

In addition, the type of storage room and the number of storage rooms are only an example.

The refrigerating compartment 21 is a storage compartment of a refrigerating temperature zone cooled to 0° C. to 5° C., and is disposed at the uppermost portion of the casing 1 . The freezing compartment 22 is a storage compartment of a freezing temperature zone of -15 ° C to -20 ° C which is set to freeze the storage, and is disposed below the refrigerator compartment 21 . The vegetable compartment 23 is a storage compartment set to a temperature zone of 0° C. to 5° C. suitable for storage of vegetables, and is disposed below the freezing compartment 22 .

Each of the storage chambers is provided with a door piece that covers the opening of each storage compartment so as to be freely openable and closable. In detail, the opening portion of the refrigerating chamber 21 is provided to cover the door piece 24 of the opening portion so as to be freely openable and closable. The opening portion of the freezing chamber 22 is provided to cover the door piece 25 of the opening so as to be openable and closable. The opening portion of the vegetable and fruit chamber 23 is provided to cover the door piece 26 of the opening so as to be openable and closable. Further, temperature sensors for detecting the temperatures of the respective storage compartments are also provided in each of the storage compartments. In detail, the temperature sensing device 31 is disposed in the refrigerating chamber 21, and the temperature sensor 32 is disposed in the freezing chamber 22, and the temperature sensor 33 is disposed in the vegetable and fruit chamber 23.

The air passage 3 is formed on the back side of the storage compartment. The air passage 3 communicates with each storage chamber by blowing an air passage and a return air passage. In detail, the air passage 3 and the refrigerating chamber 21 are connected by blowing the air passage 4 and a return air passage (not shown). The air passage 3 and the freezing chamber 22 are connected by blowing the air passage 5 and the return air passage 7. The air passage 3 and the vegetable and fruit chamber 23 are connected by blowing the air passage 6 and the return air passage 8.

As described above, the air passage 3 is provided with a cooler 54. The cooler 54 is for cooling the air flowing through the air passage 3, in particular, the air that flows into the air passage 3 from the storage chamber and is supplied to the storage chamber. Further, a fan 10 that blows air cooled by the cooler 54 to each of the storage compartments is also provided above the cooler 3 such as the cooler 54 in the air passage 3. Further, in the air passage 3, for example, below the cooler 54, a radiant heater 11 that heats the entire cooler 54 by radiant heat during the defrosting operation is also provided.

In other words, the air cooled by the cooler 54 flows into the refrigerating chamber 21 through the air outlet 4, and the food or the like stored in the refrigerating chamber 21 is cooled. Further, the air cooled by the food or the like is returned to the air passage 3 through a return air passage (not shown), and is cooled again by the cooler 54. In addition, the air cooled by the cooler 54 flows into the freezing compartment 22 through the blowing air passage 5, and cools the food or the like stored in the freezing compartment 22. Further, the air cooled by the food or the like is returned to the air passage 3 through the return air passage 7, and is cooled again by the cooler 54. Further, the air cooled by the cooler 54 is introduced into the vegetable compartment 23 through the blowing air passage 6, and the food or the like stored in the vegetable compartment 23 is cooled. Further, the air cooled by the food or the like is returned to the air passage 3 through the return air passage 8, and the oil cooler 54 is cooled again.

Further, in the first embodiment, the return air passage that communicates with each of the storage compartments and the air passage 3 communicates with the air passage 3 at a position below the cooler 54. That is, in the first embodiment, the lower end of the cooler 54 is an air inflow port, and the upper end of the cooler 54 is an air discharge port.

Further, in the first embodiment, a damper 9a is provided in the air outlet duct 4 connecting the air passage 3 and the refrigerating chamber 21. Further, a windshield 9b is provided in the blowing air passage 6 connecting the air passage 3 and the vegetable and fruit chamber 23. In other words, the supply amount of the cooling air supplied to the refrigerating compartment 21 can be adjusted by opening and closing the windshield 9a. Further, the supply amount of the cooling air to the vegetable compartment 23 can be adjusted by the opening and closing of the windshield 9b.

The cooler 54 described above constitutes the refrigeration cycle 50. In the refrigeration cycle circuit 50, the compressor 51, the radiator 52, the pressure reducing device 53, and the cooler 54 are connected by piping.

The compressor 51 sucks in the low-temperature and low-pressure refrigerant flowing out of the cooler 54, and compresses it into a high-temperature high-pressure gas refrigerant. This compressor 51 is provided in the machine room 2 formed on the back side of the lower portion of the casing 1. The radiator 52 exotherms the high-temperature and high-pressure gas refrigerant compressed by the compressor 51, so that the gas refrigerant is condensed into a high-pressure liquid refrigerant. The radiator 52 is, for example, a fin tube type heat exchanger provided in the machine room 2.

The decompression device 53 is a capillary or an electromagnetic expansion valve or the like, and is a device that expands the high-pressure liquid refrigerant flowing out of the radiator 52 into a low-temperature low-pressure gas-liquid two-phase refrigerant. The pressure reducing device 53 is provided in the machine room 2. The cooler 54 is, for example, a fin-and-tube heat exchanger that heat-exchanges low-temperature and low-pressure gas-liquid two-phase refrigerant flowing out of the pressure reducing device 53 and air flowing out from the respective storage chambers to cool the air. s installation.

Further, the refrigerator 100 of the first embodiment has a control device 60 composed of, for example, a microcomputer. The control device 60 is provided, for example, on the upper rear side of the casing 1, and includes a control unit 61, a determination unit 62, a timer unit 63, a memory unit 64, and the like. In addition, in the first figure, the control device 60 is not shown in the drawings for the sake of convenience.

The control unit 61 controls the start and stop of the compressor 51, the number of revolutions of the compressor 51, the start and stop of the fan 10, the number of revolutions of the fan 10, the opening degree of the windshields 9a and 9b, and the opening degree of the decompression device 53, Whether or not the radiant heater 11 is energized, and the heating capacity [W] (that is, power consumption) when the radiant heater 11 is energized is used. The determination unit 62 is a device that determines the amount of frost formed by the cooler 54. In the first embodiment, the determination unit 62 determines whether it is the first frosting state in which the frost amount of the cooler 54 is large or the second frosting state in which the frost amount of the cooler 54 is small. The timer unit 63 is a device that measures the time such as the operation time of the refrigerator 100. The memory unit 64 stores the numerical values, mathematical expressions, tables, and the like used when the control unit 61 controls the control target and the determination unit 62 determines the frost amount.

Here, in the refrigerator 100 of the first embodiment, when the frost amount of the cooler 54 is large and the amount of frost is small, the heating capacity of the radiant heater 11 is different. Therefore, the refrigerator 100 is provided with, for example, a circuit to be described later.

Fig. 2 is a view showing an example of a circuit of a refrigerator in the first embodiment of the present invention.

In the circuit 70 shown in FIG. 2, between the radiant heater 11 and the power source 71, the first wiring portion 72 having the resistor 74 and the second wiring portion 73 having no resistor are connected in parallel. Further, the circuit 70 shown in Fig. 2 has a switch 75 which can be switched between the power source 71, the closed circuit in which the first wiring portion 72 and the radiant heater 11 are connected, or the power source 71, the second wiring portion 73, and the radiant heater 11 are connected. Closed circuit. By switching the switch 75 to the closed circuit in which the power source 71, the second wiring portion 73, and the radiant heater 11 are connected, the heating capacity of the radiant heater 11 can be increased. Further, by switching the switch 75 to the power source 71, the first wiring portion 72 having the resistor body 74, and the closed circuit connected to the radiant heater 11, the current flowing to the radiant heater 11 is reduced, and the radiant heater 11 can be made. The heating capacity becomes smaller.

Further, the switching of the switch 75 is performed by the control unit 61. In addition, the second wiring portion 73 may be configured to have a lower resistance than the first wiring portion. Therefore, a resistor having a lower resistance than the resistor 74 may be provided on the second wiring portion.

Fig. 3 is a view showing an example of a circuit of a refrigerator in the first embodiment of the present invention. When the circuit 70 is configured as described above, the heating capacity of the radiant heater 11 can be made different when the amount of frost of the cooler 54 is large and the amount of frost is large.

That is, the circuit 70 shown in Fig. 3 has a switch 75 which can be switched to a closed circuit in which the first power source 76 and the radiant heater 11 are connected, or a closed circuit in which the second power source 77 and the radiant heater 11 are connected. As long as the supply voltage of the first power source 76 and the supply voltage of the second power source 77 are different, the heating capacity of the radiant heater 11 can be different by switching the switch 75. Further, the first power source 76 and the second power source 77 do not necessarily belong to the configuration of the refrigerator 100. When all of the two power supplies having different supply voltages are provided in the installation field of the refrigerator 100, these power sources may be used as the first power source 76 and the second power source 77. Further, for example, the circuit 70 has two transformers, and these transformers are connected to a commercial power source or the like, and these transformers may be used as the first power source 76 and the second power source 77. Further, for example, one of the first power source 76 and the second power source 77 is a commercial power source, and the other of the first power source 76 and the second power source 77 may be a transformer.

[Action Description]

The refrigerator 100 configured as described above operates in accordance with a mode as will be described later.

(usually running)

The normal operation for cooling the food or the like in the storage compartment is performed as will be described later.

The control unit 61 controls the compressor 51 such that the detected value of the temperature sensor 32 provided in the freezing compartment 22 is equal to the set temperature stored in the memory unit 64. That is, when the detected value of the temperature sensor 32 is higher than the set temperature, the control unit 61 activates the compressor 51. Further, when the detected value of the temperature sensor 32 is lower than the set temperature, the control unit 61 stops the compressor 51. It is also possible to change the number of revolutions of the compressor 51 in accordance with the difference between the detected value of the temperature sensor 32 and the set temperature while the compressor 51 is operating.

Further, the control unit 61 controls the opening degree of the windshield 9a so that the detected value of the temperature sensor 31 provided in the freezing compartment 21 is equal to the set temperature stored in the memory section 64. That is, when the detected value of the temperature sensor 31 is higher than the set temperature, the control unit 61 opens the windshield 9a to supply the cooling air to the refrigerating compartment 21. Further, when the detected value of the temperature sensor 31 is lower than the set temperature, the control unit 61 turns off the windshield 9a. When the cooling air is being supplied to the refrigerating compartment 21, the opening degree of the windshield 9a may be changed depending on the difference between the detected value of the temperature sensor 31 and the set temperature.

Similarly, the control unit 61 controls the opening degree of the windshield 9b so that the detected value of the temperature sensor 33 provided in the fruit and vegetable compartment 23 is equal to the set temperature stored in the memory section 64. That is, when the detected value of the temperature sensor 33 is higher than the set temperature, the control unit 61 opens the windshield 9b to supply the cooling air to the vegetable compartment 23. Further, when the detected value of the temperature sensor 33 is lower than the set temperature, the control unit 61 turns off the windshield 9b. When the cooling air is being supplied to the vegetable compartment 23, the opening degree of the windshield 9b may be changed depending on the difference between the detected value of the temperature sensor 33 and the set temperature.

(defrost operation)

In the normal operation, when the door piece of the storage compartment is opened and closed in order to insert or take out food or the like, humid air outside the refrigerator flows into the storage compartment. In addition, water vapor is also generated in foods and the like stored in the storage room. Therefore, the air which flows back from the storage compartment to the air passage 3 contains water vapor generated by food or the like. Therefore, as the normal operation continues, the water vapor contained in the return air from the storage compartment becomes frost and adheres to the cooler 54. Moreover, as the amount of frosting of the cooler 54 increases, the cooling performance of the cooler 54 decreases. Therefore, it is necessary to periodically remove the frost attached to the cooler 54.

Further, in the first embodiment, for example, when the running time of the refrigerator 100 exceeds a predetermined time stored in the storage unit 64, the control unit 61 starts defrosting of the cooler 54 (i.e., defrosting operation). The prescribed time is, for example, one day. Further, the operation of the refrigerator 100 is measured by the timer unit 63.

Further, for example, when the compressor 51 is continuously driven for a predetermined time or longer and the inside of the freezing compartment 22 cannot be cooled to the set temperature, the control unit 61 performs the defrosting operation. In addition, whether or not the compressor 51 has been continuously driven for a predetermined time or longer is determined by comparing the operation time of the compressor 51 measured by the timer unit 63 with a predetermined time stored in the storage unit 64. This determination is performed by, for example, the control unit 61 or the determination unit 62.

Further, the refrigerator 100 of the first embodiment includes a temperature sensor 34 that detects the temperature of the cooler 54. When the detected value of the temperature sensor 34 exceeds the predetermined temperature stored in the memory unit 64, the defrosting operation is ended. The specified temperature is, for example, 5 °C. That is, the control unit 61 stops energizing the radiant heater 11. As will be described later, the cooler 54 starts to form frost from the lower end side which is an air inflow port. Then, the defrosting operation is performed, and the frost attached to the lower end side of the cooler 54 is finally melted. Therefore, it is preferable that the temperature sensor 34 for judging the end of the defrosting operation is provided near the lower end of the cooler 54.

Further, the temperature sensor 34 corresponds to the first temperature sensor of the present invention.

Here, in the past refrigerator, when the defrosting operation is performed, the heating capacity [W] of the heater is fixed irrespective of the amount of frost formed by the cooler. Therefore, the past refrigerator has a problem as described later.

Fig. 4 is a perspective view showing the inside of the air passage of the refrigerator in the first embodiment of the present invention. Further, the hollow arrow shown in Fig. 4 indicates the direction in which the air flows in the air passage 3.

As described above, the return air from each of the storage chambers flows into the cooler 54 from the lower end of the cooler 54 as the air inlet, and then flows out from the upper end of the cooler 54 which is the air discharge port. At this time, in a state where the cooler 54 is not frosted, the return air from each of the storage compartments is easily separated from the vicinity of the center where the ventilation resistance is less in the lower end of the cooler 54 (in other words, the position farther from the side wall of the air passage 3). Flow into the cooler 54. Therefore, the cooler 54 first starts frosting from the vicinity of the center of the lower end shown by the range A in Fig. 4. Further, as the frosting in the range A progresses, the ventilation resistance of the range A becomes large. Therefore, the cooler 54 starts frosting in the range B of the lower end as the frost formation in the range A progresses. Then, when the ranges A, B are frosted, the frosting proceeds toward the upper end side of the cooler 54, and also frosts in the range C, so that the cooler 54 is frosted as a whole.

That is, in the state in which the frost amount of the cooler 54 is small, the amount of frost on the air discharge port side of the cooler 54 is smaller than the amount of frost on the air inlet side of the cooler 54. Therefore, when the heating capacity of the radiant heater 11 is constant regardless of the amount of frosting, the temperature of the cooler 54 during the defrosting operation is as shown in FIG. 5 which will be described later.

Fig. 5 is a view showing changes in temperature of the cooler when the cooler in the state where the amount of frost is small is defrosted in the conventional method. Further, the thick solid line shown in Fig. 5 indicates the temperature in the vicinity of the upper end of the cooler 54 (i.e., in the vicinity of the air discharge port). Further, the thick broken line shown in Fig. 5 indicates the temperature near the lower end of the cooler 54 (i.e., near the air flow inlet).

When the defrosting operation is started and the cooler 54 is heated by the radiant heater 11, the temperature of the entire cooler 54 gradually rises (state D). Then, it becomes 0 °C like the frost until the frost is completely melted, and the temperature of the entire cooler 54 is maintained at 0 ° C (state E). As described above, in the state in which the frost amount of the cooler 54 is small, the amount of frost on the upper end side of the cooler 54 on the air discharge port side is smaller than the knot on the lower end side of the cooler 54 as the air inlet side. The amount of frost. Therefore, before the frost near the lower end of the cooler 54 is completely melted, the frost near the upper end of the cooler 54 is completely melted, and the temperature near the upper end of the cooler 54 rises (state F1). At this time, the frost was not completely melted near the lower end near the upper end, and the frost was still maintained at 0 °C. Thereafter, when the frost near the lower end of the cooler 54 is also completely melted, the temperature near the lower end of the cooler 54 also starts to rise (state G1). Then, when the detected value of the temperature sensor 34 provided in the cooler 54 exceeds a predetermined temperature (for example, 5 ° C), the defrosting operation is ended. That is, the control unit 61 stops energizing the radiant heater 11.

When the defrosting operation of the cooler 54 in the state in which the frost amount is small is performed, the heating capacity of the radiant heater 11 is made constant regardless of the amount of frosting in the past, and when the amount of frosting is large, When the defrosting operation sets the heating capacity as a standard, the heating capacity is excessive. Therefore, in the state F1, the temperature increase rate near the upper end of the cooler 54 becomes large. That is, the vicinity of the upper end of the cooler 54 has been excessively heated before the temperature near the lower end of the cooler 54 rises. Therefore, as indicated by Ta in Fig. 5, when the defrosting operation ends, the temperature near the upper end of the cooler 54 has excessively risen. Therefore, when returning to the normal operation, the air supplied to the storage compartment is heated on the upper end side of the cooler 54, so that the temperature in the storage compartment rises. In addition, in order to cool the air in the storage compartment where the temperature has risen, it is necessary to consume electric power, so that the power consumption is increased.

In order to solve the above problem, it is considered to reduce the heating capacity of the radiant heater 11. However, in the case where the heating capacity of the radiant heater 11 is made small as described above, in the past method in which the heating capacity of the radiant heater 11 is constant regardless of the amount of frosting, the cooler for which the amount of frost is to be increased is large. 54 Defrost will lengthen the defrost time. That is, the cooled air cannot be supplied to the storage compartment for a long time. Therefore, when the defrosting operation is performed by the conventional method, even if the heating capacity of the heater is made small, there is a problem that the temperature in the storage chamber rises. In addition, in order to cool the air in the storage compartment where the temperature has risen, it is necessary to consume electric power, so that the power consumption is increased.

Therefore, in the refrigerator 100 of the first embodiment, the first defrosting operation in the first frosting state in which the frost amount of the cooler 54 is large and the second frosting state in which the frost amount of the cooler 54 is small The second defrosting operation causes the heating capacity of the radiant heater 11 to be different. More specifically, in the refrigerator 100 of the first embodiment, the second capacity of the heating capacity of the radiant heater 11 during the second frosting operation is lower than the heating capacity of the radiant heater 11 during the first frosting operation. The first capacity. For example, the second capacity of the heating capacity of the radiant heater 11 during the second frosting operation is 50% of the rated capacity, so that the first capacity of the heating capacity of the radiant heater 11 during the first frosting operation is 100% of the fixed capacity.

Fig. 6 is a view showing changes in temperature of the cooler when the cooler in the state in which the amount of frost is small is defrosted in the refrigerator according to the first embodiment of the present invention. Further, the thick solid line shown in Fig. 6 indicates the temperature near the upper end of the cooler 54 (i.e., near the air discharge port). Further, the thick broken line shown in Fig. 6 indicates the temperature near the lower end of the cooler 54 (i.e., near the air flow inlet).

In the refrigerator 100 of the first embodiment, the temperature change of the cooler 54 during the defrosting operation is basically the same as in the past. That is, when the defrosting operation is started and the cooler 54 is heated by the radiant heater 11, the temperature of the entire cooler 54 gradually rises (state D). Then, it becomes 0 ° C like the frost until the frost is completely melted, and the temperature of the entire cooler 54 is maintained at 0 ° C (state E). As described above, in the second frosting state in which the frost amount of the cooler 54 is small, the amount of frost on the upper end side of the cooler 54 on the air discharge port side is smaller than the lower end side of the cooler 54 as the air inlet side. The amount of frosting. Therefore, before the frost near the lower end of the cooler 54 is completely melted, the frost near the upper end of the cooler 54 is completely melted, and the temperature near the upper end of the cooler 54 rises (state F2).

At this time, in the refrigerator 100 of the first embodiment, the heating capacity of the radiant heater 11 is reduced in the second defrosting operation in the second frosting state in which the frost amount of the cooler 54 is small. Therefore, in a state where the amount of frost formation is more than the temperature near the lower end near the upper end, the temperature rise near the upper end of the cooler 54 becomes gentle. Therefore, as shown by Tb in FIG. 6, the refrigerator 100 according to the first embodiment can suppress an increase in temperature in the vicinity of the upper end of the cooler 54 when the defrosting operation is completed. In other words, in the refrigerator 100 of the first embodiment, when the air is returned to the normal operation, the air supplied to the storage chamber is heated on the upper end side of the cooler 54, and the temperature rise in the storage chamber can be suppressed. In addition, it is possible to reduce the power required to re-cool the air in the storage compartment where the temperature has risen.

Further, in the refrigerator 100 of the first embodiment, in the first defrosting operation in the first frosting state in which the frost amount of the cooler 54 is large, the heating capacity of the radiant heater 11 is increased. Therefore, the refrigerator 100 of the first embodiment can prevent the time of the first defrosting operation from being lengthened. Therefore, even if the refrigerator 100 of the first embodiment returns to the normal operation after the first defrosting operation, the temperature rise in the storage compartment can be suppressed, and the air in the storage compartment where the temperature has risen can be reduced. The amount of electricity consumed.

Further, in the second defrosting operation in the second frosting state in which the frost amount of the cooler 54 is small, the heating capacity of the radiant heater 11 can be controlled as described later.

Fig. 7 is a view showing another example of the defrosting operation in the state in which the amount of frost formation is small in the refrigerator of the first embodiment of the present invention.

For example, in the second defrosting operation in the second frosting state in which the frost amount of the cooler 54 is small, the radiant can be heated before the frost near the upper end of the cooler 54 on the air discharge port side is completely melted. The heating capacity of the device 11 is larger than the second capacity. For example, the heating capacity of the radiant heater 11 can be made 100% of the rated capacity. Then, the heating capacity of the radiant heater 11 is then lowered to make it the second capacity. For example, the heating capacity of the radiant heater 11 can be made 50% of the rated capacity. By controlling the heating capacity of the radiant heater 11 as described above, the time of the second defrosting operation can be shortened, and the temperature in the storage chamber can be suppressed from rising during the second defrosting operation.

When the heating capacity of the radiant heater 11 is controlled as described above, the radiant heating is improved in a state where the detected value of the temperature sensor 34 that detects the temperature of the cooler 54 is lower than the predetermined value stored in the memory unit 64. The heating capacity of the device 11 may be such that the heating capacity of the radiant heater 11 is lowered after the detected value of the temperature sensor 34 has been increased to a predetermined value or more. Here, the temperature of the predetermined value is lower than a temperature for determining the predetermined temperature at which the defrosting operation ends, and is higher than 0 ° C, for example, 1 ° C. Further, the comparison between the detected value of the temperature sensor 34 and the predetermined value is performed by, for example, the control unit 61.

(judging amount of frost)

The determination of the frosting state of the cooler 54 as described above is performed in accordance with, for example, a method to be described later.

Fig. 8 is a view showing a temperature change of a cooler when a radiant heater is energized in the refrigerator in the first embodiment of the present invention. In addition, FIG. 9 is a flowchart showing an example of a method of determining the frost amount of the cooler in the refrigerator according to the first embodiment of the present invention.

The heat capacity of the cooler 54 is determined by the material used for the cooler 54, the size of the material, and the like. Further, when frost adheres to the cooler 54, the heat capacity of the cooler 54 is a value that combines the frost heat capacity. Therefore, depending on the heat capacity of the cooler 54 and the heating capacity of the radiant heater 11, it is possible to predict the temperature rise amount of the cooler 54 when the cooler 54 is heated by the radiant heater 11 for a predetermined time t1. That is, as shown in Fig. 8, when the cooler 54 is heated by the radiant heater 11 for a predetermined time t1, the amount of temperature rise of the cooler 54 is smaller as the amount of frost is increased. Therefore, the amount of frost rising of the cooler 54 can be determined by the amount of temperature rise.

In this case, the determination unit 62 determines the amount of frost formed by the cooler 54 based on, for example, the flow shown in FIG.

When the normal operation is switched to the defrosting operation (that is, the defrosting operation is started), the determination unit 62 starts the determination of the amount of frost formation (step S11). Then, in step S12, the determination unit 62 obtains the detected value T1 of the temperature sensor 34 (that is, the temperature T1 of the cooler 54) before energizing the radiant heater 11. After step S12, in step S13, the control unit 61 energizes the radiant heater 11 to start heating of the cooler 54. Further, the heating capacity of the radiant heater 11 at this time is arbitrary.

After step S13, in step S14, the timer unit 63 measures the heating time of the radiation heater 11. Then, when the measurement time of the timer unit 63 reaches the predetermined time t1 stored in the storage unit 64, the determination unit 62 acquires the detected value T2 of the temperature sensor 34 (that is, the temperature T2 of the cooler 54) in step S15. And calculate the subtraction value after subtracting T1 from T2 as the temperature difference ΔT. Thereafter, in step S16, the determination unit 62 performs comparison to determine whether or not the temperature difference ΔT is larger than the first determination value stored in the storage unit 64. When the temperature difference ΔT is larger than the first determination value, the determination unit 62 determines that the frosting state of the cooler 54 is the second frosting state in which the frost amount is small (step S17). When the temperature difference ΔT is equal to or less than the first determination value, the determination unit 62 determines that the frosting state of the cooler 54 is the first frosting state in which the frost amount is large (step S18).

Further, for example, the judgment of the frosting state of the cooler 54 can be performed in accordance with the method described later.

Fig. 10 is a view showing the relationship between the operation time from the end of the defrosting operation and the frosting amount of the cooler in the refrigerator in the first embodiment of the present invention. Fig. 11 is a view showing the relationship between the number of opening and closing of the door piece and the amount of frost formed by the cooler in the refrigerator according to the first embodiment of the present invention. Fig. 12 is a side longitudinal sectional view showing an example of the refrigerator in the first embodiment of the present invention. In addition, FIG. 13 is a flowchart showing an example of a method of determining the frost amount of the cooler in the refrigerator in the first embodiment of the present invention.

When the normal operation is resumed after the defrosting operation is completed, as shown in Fig. 10, the amount of frost formed by the cooler 54 increases, for example, as a function of time. In addition, when the door piece of the storage compartment is opened and closed, humid air outside the refrigerator 100 flows into the storage compartment. Therefore, as shown in Fig. 11, the frost amount of the cooler 54 is increased stepwise every time the flap is opened and closed. That is, the number of opening and closing of the door piece is proportional to the amount of frost formed by the cooler 54. Therefore, it is possible to estimate (in other words, determine) the amount of frost formed by the cooler 54 in accordance with the time from the previous defrosting operation to the current defrosting operation and the number of times the door piece is opened and closed during the period.

In this case, as shown in FIG. 12, the opening and closing sensor 35 for detecting the opening and closing of the door piece 24 of the refrigerating compartment 21, and the opening and closing of the door piece 25 of the freezing compartment 22 are provided in the refrigerator 100. The sheet opening and closing sensor 35 and the door opening and closing sensor 35 for detecting the opening and closing of the door piece 25 of the vegetable and fruit chamber 23. Then, the determination unit 62 determines the amount of frost formed by the cooler 54 based on, for example, the flow shown in FIG.

In other words, the determination unit 62 starts the determination of the amount of frost formation when the defrosting operation is completed (step S21). Then, in step S22, the determination unit 62 determines whether or not any of the door pieces of the storage compartment is opened and closed based on the detected value of the shutter opening/closing sensor 35. Then, when any of the door pieces of the storage compartment is opened and closed, the determination unit 62 adds "1" to the number of opening and closing of the door piece stored in the storage unit 64 in step S24. Further, at the time when the defrosting operation is started, the number of opening and closing of the door piece is "0".

In step S23, the timer unit 63 measures the elapsed time from the end of the defrosting operation. Further, in step S23, the determination unit 62 acquires the elapsed time measured by the timer unit 63. Then, in step S25, the determination unit 62 determines whether or not the defrosting operation is to be started. In other words, the determination unit 62 determines whether or not the elapsed time measured by the timer unit 63 exceeds the predetermined time stored in the storage unit 64. Further, in the case where the defrosting operation is not started, step S22 to step S25 are repeatedly executed.

When the defrosting operation is to be started, the determination unit 62 estimates the cooler 54 based on the time from the previous defrosting operation to the current defrosting operation and the number of times the door piece is opened and closed during the period. The amount of frosting. Further, the relationship between the elapsed time from the end of the defrosting operation and the frost amount of the cooler 54 shown in Fig. 10 is stored in the memory unit 64 in the form of a table or a mathematical expression. Further, the relationship between the number of opening and closing of the door piece shown in Fig. 11 and the amount of frost formed by the cooler 54 is stored in the memory unit 64 in the form of a table or a mathematical expression. The determination unit 62 estimates the frost amount x of the cooler 54 using the table or the mathematical expression.

After step S26, in step S27, the determination unit 62 determines whether or not the estimated frost amount x is larger than the second determination value stored in the storage unit 64. When the frost amount x is larger than the second determination value, the determination unit 62 determines that the frosting state of the cooler 54 is the first frosting state in which the frost amount is large (step S28). When the frosting amount x is equal to or less than the second determination value, the determination unit 62 determines that the frosting state of the cooler 54 is the second frosting state in which the frost amount is small (step S29).

Here, it is not necessary to provide the door opening/closing sensor 35 for all the door pieces as long as it corresponds to at least one door piece setting. In the case where the door opening and closing sensor 35 is provided corresponding to all of the door pieces, in the case where the door piece opening and closing sensor 35 is provided corresponding to a part of the door pieces, the estimation accuracy of the frost amount of the cooler 54 is lowered, However, since the door opening and closing sensor 35 can be reduced, the refrigerator 100 can be manufactured at low cost. In addition, when the door opening/closing sensor 35 is provided in a part of the door piece, the door opening/closing sensor 35 that detects the opening and closing of the door piece 24 of the refrigerator compartment 21 may be provided. This is because the door piece 24 of the refrigerating compartment 21 is the door piece which is most easily opened and closed, and therefore, the humid air outside the refrigerator 100 is most likely to flow into the refrigerating compartment 21. That is, this is because the humid air outside the refrigerator 100 flowing into the refrigerating compartment 21 is most likely to frost the cooler 54.

Further, for example, the determination of the frosting state of the cooler 54 can be performed in accordance with the method described later.

Fig. 14 is a view showing the P-Q characteristics (air volume-static pressure characteristics) of the fan of the refrigerator in the first embodiment of the present invention. Fig. 15 is a side longitudinal sectional view showing an example of the refrigerator in the first embodiment of the present invention. In addition, FIG. 16 is a flowchart showing an example of a method of determining the frost amount of the cooler in the refrigerator according to the first embodiment of the present invention.

When the normal operation is resumed after the defrosting operation is completed, the amount of frost of the cooler 54 increases as time passes. Further, since the cross-sectional area of the air passage in the cooler 54 decreases as the amount of frost formed by the cooler 54 increases, as shown in Fig. 14, the ventilation resistance of the air sucked by the fan 10 and passed through the cooler 54 is also from H1. Increase to H2. In addition, the current value of the input fan 10 also increases. Therefore, the amount of frost generated by the cooler 54 can be determined using the current value of the input fan 10.

In this case, as shown in FIG. 15, the input current detecting sensor 36 for detecting the current value input to the fan 10 may be provided in the refrigerator 100. Then, the determination unit 62 determines the amount of frost formed by the cooler 54 based on, for example, the flow shown in FIG.

That is, when switching from the normal operation to the defrosting operation, the determination unit 62 starts the determination of the amount of frost formation (step S31). Then, in step S32, the determination unit 62 acquires the detected value y of the input current detection sensor 36, that is, the current value y input to the fan 10. Thereafter, in step S33, the determination unit 62 performs comparison to determine whether or not the current value y is larger than the third determination value stored in the storage unit 64. When the current value y is larger than the third determination value, the determination unit 62 determines that the frosting state of the cooler 54 is the first frosting state in which the frost amount is large (step S34). When the current value y is equal to or less than the third determination value, the determination unit 62 determines that the frosting state of the cooler 54 is the second frosting state in which the frost amount is small (step S35).

In addition, the current value input to the fan 10 also varies depending on the number of revolutions of the fan 10. In addition, the number of revolutions of the fan 10 can also be variably controlled depending on the temperature of the cooler 54. Therefore, the third judgment value can be changed in accordance with at least one of the number of revolutions of the fan 10 and the temperature of the cooler 54. In other words, at least one of the number of revolutions of the fan 10 and the temperature of the cooler 54 may be previously stored in the memory unit 64 as a variable to obtain a formula for the third judgment value.

In addition, there is a corresponding relationship in which the power consumption of the fan 10 increases as the current value of the input fan 10 increases. Therefore, the refrigerator 100 can be provided with a sensor that detects the power consumption of the fan 10, compares the detected value of the sensor with the third determination value, and determines the frosting state of the cooler 54 accordingly.

Further, for example, the judgment of the frosting state of the cooler 54 can be performed in accordance with the method described later.

Fig. 17 is a flowchart showing an example of a method of determining the frost amount of the cooler in the refrigerator in the first embodiment of the present invention.

When the normal operation is resumed after the defrosting operation is completed, the amount of frost of the cooler 54 increases as time passes. Moreover, as described above, the ventilating resistance of the cooler 54 also increases as the amount of frosting of the cooler 54 increases. In addition, as the amount of frosting of the cooler 54 gradually increases, the fin efficiency deteriorates due to frosting on the surface of the cooler 54, and the heat exchange performance of the cooler 54 also decreases. Therefore, in the refrigeration cycle 50, when the heat exchange performance of the cooler 54 is deteriorated, the temperature of the cooler 54 (i.e., the evaporation temperature of the refrigerant flowing in the cooler 54) is lowered. Therefore, the amount of frost of the cooler 54 can be judged by the temperature of the cooler 54 (that is, the detected value of the temperature sensor 34).

In this case, the determination unit 62 determines the amount of frost formed by the cooler 54 based on, for example, the flow shown in FIG.

That is, when switching from the normal operation to the defrosting operation, the determination unit 62 starts the determination of the amount of frost formation (step S41). Then, in step S42, the determination unit 62 acquires the detected value T3 of the temperature sensor 34 (that is, the temperature T3 of the cooler 54). Thereafter, in step S43, the determination unit 62 performs comparison to determine whether or not the detected value T3 is larger than the fourth determination value stored in the storage unit 64. When the detected value T3 is larger than the fourth determination value, the determination unit 62 determines that the frosting state of the cooler 54 is the second frosting state in which the frost amount is small (step S44). When the detected value T3 is equal to or less than the fourth determination value, the determination unit 62 determines that the frosting state of the cooler 54 is the first frosting state in which the frost amount is large (step S45).

Further, in a state before the cooler 54 is frosted, the number of revolutions of the compressor 51 is changed, and the temperature of the cooler 54 (that is, the evaporation temperature of the refrigerant flowing in the cooler 54) changes. Further, the evaporation temperature of the refrigerant flowing in the cooler 54 may vary depending on the set temperature of the freezing compartment 22. Therefore, the fourth judgment value can be changed in accordance with at least one of the number of revolutions of the compressor 51 and the set temperature of the freezing compartment 22. In other words, at least one of the number of revolutions of the compressor 51 and the set temperature of the freezer compartment 22 can be stored in the memory unit 64 as a variable to obtain the formula for the fourth determination value.

Further, for example, the judgment of the frosting state of the cooler 54 can be performed in accordance with the method described later.

Fig. 18 is a view showing the relationship between the humidity in the storage compartment and the frosting amount of the cooler in the refrigerator in the first embodiment of the present invention. Fig. 19 is a side longitudinal sectional view showing an example of the refrigerator in the first embodiment of the present invention. In addition, FIG. 20 is a flowchart showing an example of a method of determining the frost amount of the cooler in the refrigerator according to the first embodiment of the present invention.

Each storage compartment of the refrigerator 100 is in a sealed state except when the door is opened and closed. Therefore, the humidity change in the storage compartment during operation of the refrigerator 100 is proportional to the amount of frost formed by the cooler 54. In detail, the higher the humidity in the storage compartment, the more the frosting amount of the cooler 54 is increased. For example, the line J1 shown in Fig. 18 indicates a state in which the humidity in the storage compartment is low. Further, the line J2 shown in Fig. 18 indicates a state in which the humidity in the storage compartment is high. Further, by comparing the integral value obtained by integrating the J1 line with time and the integral value obtained by integrating the J2 line at the same time, the integrated value of the J2 line is larger than the integral value of the J1 line. Therefore, the amount of frost formed by the cooler 54 can be determined by the integrated value of the humidity in the storage compartment.

In this case, as shown in Fig. 19, a humidity sensor 37 that detects the humidity of the refrigerator compartment 21 can be provided in the refrigerating compartment 21. Further, the determination unit 62 may determine the amount of frost formed by the cooler 54 based on, for example, the flow shown in FIG.

In other words, the determination unit 62 starts the determination of the amount of frost formation when the defrosting operation is completed (step S51). Then, in step S52, the determination unit 62 acquires the detected value of the humidity sensor 37, and calculates the integrated value K of the detected value. After step S52, in step S53, the timer unit 63 measures the elapsed time from the end of the defrosting operation. Further, in step S53, the determination unit 62 acquires the elapsed time measured by the timer unit 63. Then, in step S54, the determination unit 62 determines whether or not the defrosting operation is to be started. In other words, the determination unit 62 determines whether or not the elapsed time measured by the timer unit 63 exceeds the predetermined time stored in the storage unit 64. Further, in the case where the defrosting operation is not started, step S52 to step S54 are repeatedly executed. That is, the determination unit 62 continues the accumulation of the detected values of the humidity sensor 37 and continuously updates the integrated value K. Further, the accumulated value K is stored in, for example, the storage unit 64.

When the defrosting operation is started, the determination unit 62 compares the cumulative value K of the detected value of the humidity sensor 37 in the time from the previous defrosting operation to the current defrosting operation, and the memory in step S55. The fifth judgment value in the storage unit 64. When the cumulative value K is larger than the fifth determination value, the determination unit 62 determines that the frosting state of the cooler 54 is the first frosting state in which the frost amount is large (step S56). When the cumulative value K is equal to or less than the fifth determination value, the determination unit 62 determines that the frosting state of the cooler 54 is the second frosting state in which the frost amount is small (step S57).

Here, the installation position of the humidity sensor 37 shown in Fig. 19 is only an example. The humidity is easily detected as long as the temperature of the air is above 0 ° C. Therefore, the humidity sensor 37 can also be disposed in, for example, the vegetable compartment 23. Further, for example, the humidity sensor 37 may be provided in all of the storage rooms. The estimation accuracy of the frost amount of the cooler 54 is increased.

Embodiment 2

In the first embodiment, the radiant heater 11 that heats the entire cooler 54 by radiant heat is used to perform defrosting of the cooler 54. However, the heater for performing defrosting of the cooler 54 is not limited to the radiant heater 11. For example, a contact type heater that is in contact with the cooler 54 may be disposed in the refrigerator 100, coexisting with the radiant heater 11, or in place of the radiant heater 11. In this case, the amount of frost formed by the cooler 54 may be determined using the above-described frost amount determination method. In the first defrosting operation in the first frosting state in which the frost amount of the cooler 54 is large, the heating capacity (that is, the first capacity) of the contact heater is increased to, for example, 100% of the rated capacity. Just fine. In the second defrosting operation in the second frosting state in which the frost amount of the cooler 54 is small, the heating capacity (that is, the second capacity) of the contact heater is reduced to, for example, 50% of the constant capacity. Just fine. As a result, as described in the first embodiment, it is possible to suppress an increase in the temperature in the storage chamber in both the first frosting state and the second frosting state, and it is possible to reduce the cost of re-cooling the air in the storage compartment where the temperature has risen. Electricity.

Further, when the refrigerator 100 is provided with a contact heater, the amount of frost formed by the cooler 54 can be determined by a method described later. The configuration that is not described in the second embodiment is the same as that of the first embodiment, and the same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment.

Figure 21 is a side longitudinal sectional view showing an example of a refrigerator in a second embodiment of the present invention. Fig. 22 is a perspective view showing the inside of the air passage of the refrigerator in the second embodiment of the present invention. In addition, FIG. 23 is a flowchart showing an example of a method of determining the frost amount of the cooler in the refrigerator according to the second embodiment of the present invention.

As shown in FIGS. 21 and 22, the refrigerator 100 of the second embodiment includes a contact heater 12 that is provided in contact with the cooler 54, instead of the radiant heater 11. Further, the contact heater 12 is provided with a temperature sensor 38 for detecting the temperature of the contact heater 12.

Here, the temperature sensor 38 corresponds to the second temperature sensor of the present invention.

In the refrigerator 100 configured as described above, during the defrosting operation, the cooler 54 is directly heated by the contact heater 12 to perform defrosting of the cooler 54. Here, since the contact heater 12 and the cooler 54 are in contact with each other, the frost adhering to the cooler 54 is cooled. Therefore, during the defrosting operation, the contact heater 12 is energized, and the amount of temperature rise of the contact heater 12 decreases as the amount of frost of the cooler 54 increases after a predetermined time t1 elapses. Therefore, the amount of frost rising of the cooler 54 can be determined by the amount of temperature rise.

In this case, the determination unit 62 determines the amount of frost formed by the cooler 54 based on, for example, the flow shown in FIG.

When the normal operation is switched to the defrosting operation (that is, the defrosting operation is started), the determination unit 62 starts the determination of the amount of frost formation (step S61). Then, in step S62, the determination unit 62 obtains the detected value T4 of the temperature sensor 38 (that is, the temperature T4 of the contact heater 12) before energizing the contact heater 12. After step S62, in step S63, the control unit 61 energizes the contact heater 12 to start heating of the cooler 54. Further, the heating capacity of the contact heater 12 at this time is arbitrary.

After step S63, in step S64, the timer unit 63 measures the heating time of the contact heater 12. Then, when the measurement time of the timer unit 63 reaches the predetermined time t1 stored in the storage unit 64, the determination unit 62 acquires the detection value T5 of the temperature sensor 38 (that is, the contact type heater 12). Temperature T5), and the subtraction value after subtracting T4 from T5 is calculated as the temperature difference ΔT. Thereafter, in step S66, the determination unit 62 performs comparison to determine whether or not the temperature difference ΔT is larger than the sixth determination value stored in the storage unit 64. When the temperature difference ΔT is larger than the sixth determination value, the determination unit 62 determines that the frosting state of the cooler 54 is the second frosting state in which the frost amount is small (step S67). When the temperature difference ΔT is equal to or less than the sixth determination value, the determination unit 62 determines that the frosting state of the cooler 54 is the first frosting state in which the frost amount is large (step S68).

As described above, in the first and second embodiments described above, the amount of frost formed by the cooler 54 is determined using one determination value. Moreover, as shown in Fig. 24, with the judgment value as a reference, when the amount of frosting is more than the determination value, the heating capacity of the heater is increased, and when the amount of frosting is less than the determination value, the heater is reduced. Heating capacity. However, the method of determining the amount of frost of the cooler 54 in the present invention is not limited to such a method.

For example, as shown in Fig. 25, a plurality of judgment values can be used to determine the amount of frost formed by the cooler 54. That is, when the amount of frosting is greater than the determination value, the heating capacity of the heater is increased, and when the amount of frosting is less than the determination value, the heating capacity of the heater is decreased. The heating capacity of the heater can be made a more appropriate value depending on the amount of frost formed by the cooler 54. In other words, it is possible to further suppress the occurrence of warmth in the storage compartment, and it is possible to further shorten the defrosting time. In this case, in each of the determination values, the state in which the frosting amount is larger than the determination value corresponds to the first frosting state of the present invention, and the state in which the frosting amount is smaller than the determination value corresponds to the second frosting state of the present invention.

Further, in the determination of the frost amount of the cooler 54, each value compared with each judgment value is as described above, and has a proportional relationship with the frost amount of the cooler 54. Therefore, for example, as shown in Fig. 26, the heating capacity of the heater can be continuously made in accordance with the amount of frost formation (that is, each value compared with each judgment value in the judgment of the frost amount of the cooler 54). Variety. In other words, the smaller the amount of frosting, the smaller the heating capacity of the heater. In this case, when the arbitrary frosting amount state is the first frosting state of the present invention, the state in which the frosting amount is smaller than the state is the second frosting state of the present invention.

Further, the method of determining the frost amount of the cooler 54 shown in the first embodiment and the second embodiment is not limited to one, and a plurality of frost amount determination methods may be simultaneously performed. The amount of frost formed by the cooler 54 can be judged more correctly.

Claims (11)

 A refrigerator comprising: a storage compartment; a wind passage communicating with the storage compartment; a cooler disposed on the wind passage to cool air flowing in the air passage; and a heater that heats the cooler and In the first frosting state in which the frost is formed on the cooler, the heating capacity is the first capacity, and in the second frosting state in which the frosting of the cooler is less than the first frosting state, the heating capacity is made smaller than the first one. a second capacity of the capacity; a first temperature sensor that detects the temperature of the cooler; and a control device; wherein the control device, when the detected value of the first temperature sensor is greater than the fourth determination value, The heater is heated by the second capacity, and when the detection value of the first temperature sensor is equal to or less than the fourth determination value, the heater is heated by the first capacity. The refrigerator according to the first aspect of the invention, wherein the heating capacity of the heater is greater than the second capacity in a state in which the temperature of the cooler is lower than a predetermined value in the second frosting state; When the temperature of the cooler has become equal to or higher than the predetermined value, the heating capacity of the heater is set to the second capacity. The refrigerator according to claim 1 or 2, comprising: a first wiring portion having a resistor; the second wiring portion is configured to have a lower resistance than the first wiring portion, and is connected in parallel with the first wiring portion between the heater and the power source; and the switch is switched to the above A power supply, a closed circuit in which the first wiring portion and the heater are connected, or a closed circuit in which the power source, the second wiring portion, and the heater are connected. The refrigerator according to claim 1 or 2, further comprising: a switch that switches to a closed circuit in which the first power source and the heater are connected, or a second power source that is different in voltage from the first power source A closed circuit connected to the above heater. The refrigerator according to claim 1 or 2, wherein, when the defrosting operation is started, the heater is detected when a predetermined time has elapsed after the first temperature sensor is energized by the heater. And subtracting the difference between the detected value of the first temperature sensor before the energization of the heater is greater than the first determination value, heating the cooler with the second capacity; and when the difference is the above When the value is 1 or less, the cooler is heated by the first capacity. The refrigerator according to claim 1 or 2, comprising: a door piece that covers an opening of the storage compartment in a freely openable and closable manner; and a door opening and closing sensor that detects opening and closing of the door piece The above heater is based on the period between the previous defrosting operation and the current defrosting operation. And the amount of frost of the cooler estimated by the number of times the door piece is opened and closed in the period is less than the second determination value, and the cooler is heated by the second capacity, and is larger than the second determination value. Then, the cooler is heated by the first capacity described above. The refrigerator according to claim 1 or 2, further comprising: a fan provided in the air passage, blowing air cooled by the cooler to the storage chamber; detecting a current value input to the fan, Or a sensor for consuming power of the fan; and the heater, when the detection value of the sensor is equal to or less than a third determination value, heating the cooler with the second capacity; when the sensor is inspected When the output value is larger than the third determination value, the cooler is heated by the first capacity. The refrigerator according to any one of claims 1 to 2, further comprising: a humidity sensor that detects the humidity of the storage compartment; the heater, the previous defrosting operation to the current defrosting When the cumulative value of the detected value of the humidity sensor at the time of the operation is less than the fifth determination value, the cooler is heated by the second capacity; and if the value is greater than the fifth determination value, the first value is The capacity is used to heat the above cooler. The refrigerator according to claim 1 or 2, wherein: The heater is a contact heater provided to be in contact with the cooler; the refrigerator includes a second temperature sensor that detects a temperature of the contact heater; and the contact heater is activated when a defrosting operation is started, When the second temperature sensor has passed the predetermined time after the energization of the contact heater, the detected value of the second temperature sensor before the energization of the contact heater is subtracted. When the obtained difference is larger than the sixth determination value, the cooler is heated by the second capacity; and when the difference is equal to or less than the sixth determination value, the cooler is heated by the first capacity. A refrigerator comprising: a storage compartment; a wind passage communicating with the storage compartment; a cooler disposed on the wind passage to cool air flowing in the air passage; and a heater that heats the cooler and In the first frosting state in which the frost is formed on the cooler, the heating capacity is the first capacity, and in the second frosting state in which the frosting of the cooler is less than the first frosting state, the heating capacity is made smaller than the first one. a second capacity of the capacity; a humidity sensor that detects the humidity of the storage compartment; and a control device; wherein the control device receives the wetness of the previous defrosting operation until the current defrosting operation When the integrated value of the detected value of the sensor is equal to or less than the fifth determination value, the heater is heated by the second capacity, and if it is larger than the fifth determination value, the heater is heated by the first capacity. . A refrigerator comprising: a storage compartment; a wind passage communicating with the storage compartment; a cooler disposed on the wind passage to cool air flowing in the air passage; and a heater that heats the cooler and In the first frosting state in which the frost is formed on the cooler, the heating capacity is the first capacity, and the heating capacity is the second capacity in the second frosting state in which the frosting of the cooler is less than the first frosting state; a second temperature sensor that detects a temperature of the heater; wherein the heater is a contact heater provided to be in contact with the cooler; and when the defrosting operation is started, when sensing from the second temperature The difference between the detected value when the predetermined time has elapsed after the contact heater is energized and the detected value of the second temperature sensor before the energization of the contact heater is greater than the sixth The determination value is that the cooler is heated by the second capacity as a heating capacity, and when the difference is equal to or less than the sixth determination value, the cooler is heated by the first capacity as a heating capacity; and the second capacity is smaller than The above first capacity