Refrigerator

Abstract

To provide a refrigerator which can effectively keep a small cold room at low temperature and constant temperature.SOLUTION: A refrigerator 10 of the invention includes: a cold room 12; a small cold room 20 defined in the cold room 12; a small cold room temperature sensor 22 which measures an in-room temperature of the small cold room 20; a cooling room 115 in which air blown to the small cold room 20 is cooled by a cooler; a heating part 117 configured to defrost the cooler by heating; a blower 25 which blows air from the cooling room 115 to the cold room 12; and a calculation control unit 26. Further, the calculation control unit 26 executes a cooling cycle in which the cooler and the blower 25 are operated so that the in-room temperature of the small cold room 20 measured by the small cold room temperature sensor 22 is lower than or equal to a first upper limit temperature and higher than or equal to a first lower limit temperature and decreases the first lower limit temperature in the cooling cycle immediately before a defrosting operation.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a refrigerator, and more particularly to a refrigerator having a small refrigerator compartment inside a refrigerator compartment.

Background Art

[0002] Conventionally, a refrigerator in which a storage container is disposed inside a refrigerator compartment as described in Patent Document 1 is known. Here, a chilled container is stored at the lowermost part of the refrigerator compartment. The air blown by the blower is supplied to the refrigerator compartment via a blower passage formed at the rear side of the refrigerator compartment. On the other hand, a part of the air blown into the blower passage is blown to the chilled container without passing through the refrigerator compartment, and cold air is directly supplied to the stored items such as meat. By doing so, the temperature inside the chilled container is made lower than the temperature inside the refrigerator compartment, for example, about 0°C. Therefore, foods such as meat stored in the chilled container can be preserved.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the refrigerator described in Patent Document 1 mentioned above, there is room for improvement from the viewpoints of lowering the temperature and maintaining a constant temperature in the small refrigerator compartment.

[0005] Referring to the graph of FIG. 5, such problems will be described in detail. In this graph, the horizontal axis represents the passage of time, and the vertical axis represents temperature. Also, the temperature inside the refrigerator compartment is shown by a solid line, the temperature inside the chiller compartment is shown by a dotted line, and the temperature inside the freezer compartment is shown by a dashed-dotted line. Referring to this graph, during the defrosting process, the temperatures inside all the storage compartments are rising. The reason for this is that during the defrosting process, cooling by the evaporator is not performed, and furthermore, the inside of the cooling chamber is heated by the defrosting heater. In this case, when the temperature inside the chiller compartment becomes 0°C or higher, the meat and fish stored in the chiller compartment will temporarily melt, and there will be a problem that their freshness will deteriorate.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a refrigerator that can effectively achieve low temperature and constant temperature of a small refrigerator compartment.

Means for Solving the Problems

[0007] The refrigerator according to an embodiment of the present invention includes a refrigerator compartment, a small refrigerator compartment partitioned inside the refrigerator compartment, a small refrigerator compartment temperature sensor for measuring the temperature inside the small refrigerator compartment, a cooling chamber for cooling the air blown into the small refrigerator compartment by a cooler, a heating unit for defrosting the cooler by heating, a blower for blowing the air from the cooling chamber to the refrigerator compartment, and an arithmetic control unit. It is configured to be able to select a mode for preferentially cooling the small refrigerator compartment. When the mode for preferentially cooling the small refrigerator compartment is not selected, the arithmetic control unit executes a cooling cycle for operating the cooler and the blower so that the temperature inside the small refrigerator compartment measured by the small refrigerator compartment temperature sensor is equal to or lower than a first upper limit temperature and equal to or higher than a first lower limit temperature. When the mode for preferentially cooling the small refrigerator compartment is selected, the set value of the first lower limit temperature is decreased.

Effects of the Invention

[0008] According to the refrigerator of the present invention, it is possible to provide a refrigerator that can effectively achieve low temperature and constant temperature of a small refrigerator compartment.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0010] Hereinafter, the refrigerator 10 according to the embodiment of the present invention will be described in detail with reference to the drawings. In the description of this embodiment, the same reference numerals are generally used for the same members, and repeated descriptions are omitted.

[0011] FIG. 1 is a side cross-sectional view of the refrigerator 10.

[0012] The heat-insulating box body 11 constituting the main body of the refrigerator 10 includes an outer box 111 made of a steel plate bent into a predetermined shape, an inner box 112 made of a synthetic resin plate disposed inside and separated from the outer box 111, and a heat-insulating material 113 filled between the outer box 111 and the inner box 112.

[0013] The refrigerator compartment inside the heat-insulating box body 11 is partitioned into a refrigerator compartment 12 and a freezer compartment 13 from above. The refrigerator compartment 12 and the freezer compartment 13 are partitioned by a heat-insulating wall 17. Further, the front opening of the refrigerator compartment 12 is closed by a heat-insulating door 18, and the front opening of the freezer compartment 13 is closed by a heat-insulating door 19.

[0014] The small refrigerating chamber 20 is a refrigerating chamber partitioned from other areas of the refrigerating chamber 12 below the interior of the refrigerating chamber 12. The small refrigerating chamber 20 is a chilled chamber whose interior is cooled to a lower temperature, for example, about -3°C, than other areas of the refrigerating chamber 12. The small refrigerating chamber 20 is formed inside a storage container 21 made of synthetic resin with an open top. The storage container 21 is arranged to be pull-out forward. Inside the small refrigerating chamber 20, stored items 23 such as meat or fish are stored in a semi-frozen state.

[0015] The cooling chamber 115 is formed at the back side of the freezer compartment 13. An evaporator 116, which is a cooler, is disposed inside the cooling chamber 115. A machine room 14 is partitioned and formed at the rear side of the lower end of the refrigerator 10, and a compressor 15 is arranged in the machine room 14. The evaporator 116 and the compressor 15, together with a condenser and expansion means not shown here, form a vapor compression refrigeration cycle. By operating the vapor compression refrigeration cycle, the air inside the cooling chamber 115 is cooled by the evaporator 116, and by blowing this air into each refrigerating chamber, the temperature inside each refrigerating chamber becomes within a predetermined cooling temperature range.

[0016] The blower 25 is arranged above the evaporator 116 inside the cooling chamber 115. The blower 25 is an axial flow blower or a centrifugal blower, and blows the air inside the evaporator 116 cooled by the evaporator 116 toward the refrigerating chamber 12 and the freezer compartment 13.

[0017] The heating part 117 is inside the evaporator 116 and is arranged below the evaporator 116. The heating part 117 is, for example, a heater that generates heat by energization.

[0018] The air duct 118 is formed upward from the cooling chamber 115. An air outlet 16, which is an opening for blowing air into the refrigerating chamber 12, is formed in the upper part of the air duct 118. Also, a part of the air cooled by the evaporator 116 is blown into the freezer compartment 13. Further, a part of the air cooled by the evaporator 116 is also sent into the interior of the small refrigerating chamber 20 via the air duct 118 and the air outlet 30.

[0019] The damper 28 is an opening / closing means installed in the air duct 118. By setting the damper 28 to the open state, air can be blown from the cooling chamber 115 to the refrigerator compartment 12 and the small refrigerator compartment 20. On the other hand, by setting the damper 28 to the closed state, the air duct 118 is closed. Further, the damper 28 is a multi-damper that can individually open and close both the air duct 118 connected to the refrigerator compartment 12 and the air duct 118 connected to the small refrigerator compartment 20.

[0020] The small refrigerator compartment temperature sensor 22 is a sensor that measures the temperature inside the small refrigerator compartment 20. The freezer compartment temperature sensor 27 is a sensor that measures the temperature inside the freezer compartment 13. The defrost sensor 29 is a temperature sensor disposed inside the cooling chamber 115 in the vicinity of the evaporator 116. As will be described later, the defrost sensor 29 is used in the defrosting process for defrosting the evaporator 116.

[0021] Figure 2 is a block diagram showing the connection configuration of the refrigerator 10.

[0022] The arithmetic control unit 26 is composed of a CPU, a RAM, a ROM, etc., executes predetermined arithmetic processing based on information input from the input side terminals, and outputs the output signal generated by this processing from the output terminal side. The small refrigerator compartment temperature sensor 22, the freezer compartment temperature sensor 27, the timer 24, and the defrost sensor 29 are connected to the input side terminals of the arithmetic control unit 26. The compressor 15, the blower 25, and the heating unit 117 are connected to the output side terminals of the arithmetic control unit 26.

[0023] The small refrigerator compartment temperature sensor 22 measures the temperature inside the small refrigerator compartment 20 described above, and inputs information indicating this temperature to the arithmetic control unit 26.

[0024] The freezer compartment temperature sensor 27 measures the temperature inside the freezer compartment 13 described above, and inputs information indicating this temperature to the arithmetic control unit 26.

[0025] The timer 24 measures time or hours, and inputs information indicating these to the arithmetic control unit 26.

[0026] As will be described later, the defrost sensor 29 measures the internal temperature of the cooling chamber 115 during the defrosting process and inputs information indicating this temperature to the arithmetic control unit 26.

[0027] Based on the information output from the arithmetic control unit 26, the compressor 15 compresses the refrigerant used in the refrigeration cycle described above.

[0028] Based on the information output from the arithmetic control unit 26, the blower 25 blows the air in the cooling chamber 115 into the refrigerating chamber 12 and the freezing chamber 13.

[0029] Based on the information output from the arithmetic control unit 26, the heating unit 117 generates heat to raise the temperature inside the cooling chamber 115 and defrost the frost adhering to the evaporator 116.

[0030] The basic operation of the refrigerator 10 having the above-described configuration will be described below.

[0031] When the cooling operation is executed, the arithmetic control unit 26 cools the air inside the cooling chamber 115 by operating the compressor 15 with the evaporator 116. Further, the arithmetic control unit 26 blows the air inside the cooling chamber 115 by operating the blower 25. The blown air is blown into the refrigerating chamber 12 via the air duct 118 and the air outlet 16, thereby cooling the interior of the refrigerating chamber 12. Also, a part of the blown air is blown into the small refrigerating chamber 20, thereby cooling the interior of the small refrigerating chamber 20. Further, a part of the blown air is blown into the freezing chamber 13, thereby cooling the interior of the freezing chamber 13 to a predetermined freezing temperature range. Also, the air that has cooled each storage chamber returns to the cooling chamber 115 via a return air duct (not shown here).

[0032] The cooling operation is performed so that the temperature inside the freezer compartment 13 falls within a predetermined temperature range. Specifically, when the temperature inside the freezer compartment 13 detected by the freezer compartment temperature sensor 27 reaches or exceeds the upper limit temperature (the second upper limit temperature), the arithmetic control unit 26 operates the compressor 15 and the blower 25 to cool the inside of the freezer compartment 13. Thereafter, when the temperature inside the freezer compartment 13 detected by the freezer compartment temperature sensor 27 reaches or falls below the lower limit temperature (the second lower limit temperature), the arithmetic control unit 26 stops the compressor 15 and the blower 25 to stop the cooling of the freezer compartment 13. For example, the upper limit temperature of the freezer compartment 13 is -18°C, and the lower limit temperature is -22°C. Here, the upper limit temperature is also referred to as the ON point, and the lower limit temperature is also referred to as the OFF point.

[0033] The process in which the operation of the compressor 15 and the blower 25 starts and stops, and then starts again until the next start is referred to as one refrigeration cycle.

[0034] Similarly, the temperature of the small refrigerating compartment 20 is controlled so that the temperature inside the compartment falls within a predetermined temperature range. Specifically, when the temperature inside the small refrigerating compartment 20 detected by the small refrigerating compartment temperature sensor 22 reaches or exceeds the upper limit temperature (the first upper limit temperature), the arithmetic control unit 26 introduces air from the cooling chamber 115 into the small refrigerating compartment 20. Also, when the temperature inside the small refrigerating compartment 20 reaches or falls below the lower limit temperature (the first lower limit temperature), the arithmetic control unit 26 stops the cooling of the small refrigerating compartment 20. For example, the upper limit temperature of the small refrigerating compartment 20 is -2°C, and the lower limit temperature is -4°C.

[0035] Furthermore, the arithmetic control unit 26 similarly performs temperature control on the refrigerating compartment 12 so that the temperature inside the compartment falls within a predetermined temperature range, for example, +2°C or higher and +5°C or lower.

[0036] The defrosting operation is an operation for melting the frost adhering to the surface of the evaporator 116. Specifically, with the operation of the vapor compression refrigeration cycle, thick frost forms on the surface of the evaporator 116. If the cooling operation is continued in this state, heat transfer and air blowing will be hindered by the frost. Therefore, in the defrosting operation, the arithmetic control unit 26 stops the compressor 15 and the blower 25, closes the damper 28, and energizes the heating unit 117 to heat it, thereby performing a defrosting operation to melt and remove the frost.

[0037] Referring to the flowchart of FIG. 3, a method for performing a defrost operation while suppressing an increase in the internal temperature of the small refrigerator compartment 20 when the user selects the "Freshness Retaining Chilled Mode" will be described.

[0038] In step S10, the arithmetic control unit 26 is executing a normal cooling operation. That is, as described above, the arithmetic control unit 26 operates the compressor 15 and the blower 25 so that the internal temperature of the freezer compartment 13 detected by the freezer compartment temperature sensor 27 falls within the temperature range defined by the upper limit temperature and the lower limit temperature.

[0039] In step S11, by the user operating an operation panel (not shown here), the arithmetic control unit 26 executes the freshness retaining chilled mode. In the freshness retaining chilled mode, as will be described later, before executing the defrosting process, the internal temperature of the small refrigerator compartment 20 is lowered more than in the normal cooling cycle. Therefore, it is possible to suppress the internal temperature of the small refrigerator compartment 20 from becoming 0°C or higher during the defrosting process, and to maintain the freshness of the stored item 23 stored in the small refrigerator compartment 20 well.

[0040] In step S12, the arithmetic control unit 26 lowers the lower limit temperature of the small refrigerator compartment temperature sensor 22 of the small refrigerator compartment 20 by, for example, 2°C to 3°C with respect to the normal operation, and cools the entire small refrigerator compartment 20.

[0041] Here, the normal operation is an operation in which a mode such as the freshness retaining chilled mode is not selected. In the normal operation, in order to reduce the power consumption and save the electricity cost, the arithmetic control unit 26 cools the internal temperature of the small storage compartment 20 to, for example, about 0 degrees. On the other hand, in the freshness retaining chilled mode, the arithmetic control unit 26 lowers the lower limit temperature to about -3°C.

[0042] In step S13, when the operation integration time of the compressor 15 reaches a certain time, the arithmetic control unit 26 enters the defrost control in the freshness retaining chilled mode.

[0043] In step S14, the arithmetic control unit 26 checks, using the timer 24, whether the operation integrated time of the compressor 15 has reached a predetermined time. Here, the predetermined time is the time when defrosting in the evaporator 116 becomes necessary, for example, 88 hours.

[0044] If the answer in step S14 is YES, that is, if the operation integrated time of the compressor 15 has reached the predetermined time, the arithmetic control unit 26 proceeds to step S15.

[0045] If the answer in step S14 is NO, that is, if the operation integrated time of the compressor 15 has not reached the predetermined time, the arithmetic control unit 26 returns to step S13.

[0046] In step S15, the arithmetic control unit 26 determines whether the temperature inside the freezer compartment 13 measured by the freezer compartment temperature sensor 27 has reached the lower limit temperature of the freezer compartment (second lower limit temperature) or lower. Here, the lower limit temperature of the freezer compartment is, for example, -22°C.

[0047] If the answer in step S15 is YES, that is, if the temperature inside the freezer compartment 13 has reached the lower limit temperature of the freezer compartment or lower, the arithmetic control unit 26 proceeds to step S16.

[0048] If the answer in step S15 is NO, that is, if the temperature inside the freezer compartment 13 has not reached the lower limit temperature of the freezer compartment or lower, the arithmetic control unit 26 returns to step S13.

[0049] In step S16, the arithmetic control unit 26 further cools the inside of the small storage compartment 20 in the cooling cycle immediately before the defrost operation. Specifically, the arithmetic control unit 26 determines whether the temperature inside the small cold storage compartment 20 measured by the freezer compartment temperature sensor 27 has reached the lower limit temperature of the small storage compartment (first lower limit temperature) or lower. Here, the lower limit temperature of the small storage compartment is, for example, -4°C, which is a temperature lower than the lower limit temperature of the small storage compartment in the normal freshness-keeping chilled mode.

[0050] If YES in step S16, that is, if the temperature inside the small refrigerator compartment 20 has reached below the lower limit temperature of the small storage compartment, since the small refrigerator compartment 20 is sufficiently cooled, the arithmetic control unit 26 proceeds to step S17.

[0051] If NO in step S16, that is, if the temperature inside the small refrigerator compartment 20 has not reached below the lower limit temperature of the small storage compartment, the arithmetic control unit 26 returns to step S13.

[0052] In step S17, the arithmetic control unit 26 stops the compressor 15, thereby stopping the cooling of the cooling chamber 115 by the evaporator 116.

[0053] In step S18, after the arithmetic control unit 26 stops the compressor 15, it sets the damper 28 to a state where it blows air only to the small refrigerator compartment 20, and operates the blower 25 for a predetermined time. By doing so, prior to the defrosting process, cold air can be supplied only to the inside of the small refrigerator compartment 20, and the temperature inside the small refrigerator compartment 20 can be further reduced.

[0054] In step S19, the arithmetic control unit 26 stops the blower 25 and closes the damper 28. By closing the damper 28, it is possible to suppress the warm air heated by the heating unit 117 from entering the small refrigerator compartment 20 and the refrigerator compartment 12 during the defrosting operation.

[0055] In step S20, the arithmetic control unit 26 starts the defrosting process. Specifically, the arithmetic control unit 26 energizes the heating unit 117 to raise the temperature inside the cooling chamber 115 and melt the frost adhering to the evaporator 116.

[0056] In step S21, the arithmetic control unit 26 determines whether the temperature detected by the defrosting sensor 29 has reached the upper limit temperature.

[0057] If YES in step S21, that is, if the temperature detected by the defrosting sensor 29 has reached the upper limit temperature, the arithmetic control unit 26 proceeds to step S22. That is, the power supply to the heating unit 117 is stopped.

[0058] In the case of NO in step S21, that is, if the temperature detected by the defrost sensor 29 has not reached the upper limit temperature, the arithmetic control unit 26 proceeds to step S20.

[0059] In step S22, the arithmetic control unit 26 waits until a safety time of about several minutes has elapsed, and then operates the compressor 15 to cool the air inside the cooling chamber 115 by the evaporator 116.

[0060] In step S23, the arithmetic control unit 26 operates the blower 25 and opens the damper 28. By doing so, the air inside the cooling chamber 115 cooled by the evaporator 116 is blown into the refrigerator compartment 12, the freezer compartment 13, and the small refrigerator compartment 20.

[0061] In step S24, the arithmetic control unit 26 ends the defrosting process and returns to the normal cooling operation or the freshness-keeping chilled mode.

[0062] The above is the explanation of the defrosting operation by the refrigerator 10 according to the present embodiment.

[0063] With reference to the graph in FIG. 4, the temperature changes in the small refrigerator compartment 20 and the like in the operation of the above-described refrigerator 10 will be described. The horizontal axis of this graph indicates the elapsed time, and the vertical axis indicates the temperature inside the compartment. Further, in this graph, the temperature inside the refrigerator compartment 12 is indicated by a solid line, the temperature inside the small refrigerator compartment 20 is indicated by a dotted line, and the temperature inside the freezer compartment 13 is indicated by a dashed-dotted line.

[0064] With reference to this graph, in the cooling cycle immediately before the defrosting process, the temperature inside the small refrigerator compartment 20 has dropped to -5°C. Such a temperature drop is performed by lowering the lower limit temperature in step S12 described above.

[0065] Also, in the defrosting process, the refrigeration cycle is stopped, and further heating is performed by the heating unit 117. Therefore, the internal temperatures of the refrigerator compartment 12, the small refrigerator compartment 20, and the freezer compartment 13 gradually rise. However, since the internal temperature of the small refrigerator compartment 20 has been lowered prior to the defrosting process, the maximum temperature of the small refrigerator compartment 20 is about -1°C, and the internal temperature of the small refrigerator compartment 20 does not exceed 0°C. Thus, the stored item 23 stored in the small refrigerator compartment 20 does not melt, and its freshness can be maintained well.

[0066] According to this embodiment, the following main effects can be achieved.

[0067] That is, by lowering the lower limit temperature in the cooling cycle immediately before the defrosting operation, the internal temperature of the small refrigerator compartment 20 immediately before the defrosting operation can be lowered. Therefore, even if the temperature of the refrigerator compartment 12 rises due to the defrosting operation, it is possible to suppress the internal temperature of the small refrigerator compartment 20 from rising above 0°C, and the freshness of the food stored in the small refrigerator compartment 20 can be maintained. For example, according to this embodiment, the internal temperature of the small refrigerator compartment 20 can be set in the range of -2°C to -4°C, and the freshness of the stored item 23 stored in a semi-frozen state inside the small refrigerator compartment 20 can be maintained for, as an example, 10 days or more.

[0068] Also, when both the freezer compartment 13 is below the lower limit temperature and the small refrigerator compartment 20 is below the lower limit temperature, the defrosting operation is started. Specifically, the arithmetic control unit 26 stops the compressor 15 after lowering the internal temperatures of the freezer compartment 13 and the small refrigerator compartment 20 to the lower limit temperature immediately before defrosting, and executes the defrosting operation. Therefore, in the defrosting operation, it is possible to prevent the internal temperature of the small refrigerator compartment 20 from rising above a certain level.

[0069] Furthermore, by operating the blower 25 with the damper of the small refrigerator compartment 20 in the open state before executing the defrosting operation, the small refrigerator compartment 20 can be further cooled, and the rise in the internal temperature of the small refrigerator compartment 20 during the defrosting operation can be suppressed.

[0070] Furthermore, when the user selects a mode to preferentially cool the small refrigerator compartment 20, in the cooling cycle immediately before the defrost operation, by lowering the lower limit temperature, the small refrigerator compartment 20 can be suitably cooled according to the user's request, and furthermore, the energy required for cooling can be reduced.

[0071] The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. In addition, the above-described embodiments can be combined with each other.

[0072] The invention understood from the above-described embodiments will be described below together with its effects.

[0073] The refrigerator of the present invention includes a refrigerating compartment, a small refrigerator compartment partitioned inside the refrigerating compartment, a small refrigerator compartment temperature sensor for measuring the temperature inside the small refrigerator compartment, a cooling chamber for cooling the air blown into the small refrigerator compartment by a cooler, a heating unit for defrosting the cooler by heating, a blower for blowing the air from the cooling chamber to the refrigerating compartment, and an arithmetic control unit. The arithmetic control unit executes a cooling cycle for operating the cooler and the blower so that the temperature inside the small refrigerator compartment measured by the small refrigerator compartment temperature sensor is equal to or lower than a first upper limit temperature and equal to or higher than a first lower limit temperature. In the cooling cycle immediately before the defrost operation, the set value of the first lower limit temperature is lowered. According to the refrigerator of the present invention, the low temperature and constant temperature of the small refrigerator compartment can be effectively achieved. Specifically, by lowering the lower limit temperature in the cooling cycle immediately before the defrost operation, the temperature inside the small refrigerator compartment immediately before the defrost operation can be lowered. Therefore, even if the temperature of the refrigerating compartment rises due to the defrost operation, it is possible to suppress the excessive rise of the temperature inside the small refrigerator compartment and maintain the freshness of the food stored in the small refrigerator compartment.

[0074] In addition, the refrigerator of the present invention further includes a freezer compartment and a freezer compartment temperature sensor for measuring the temperature inside the freezer compartment. The arithmetic control unit cools the freezer compartment so that the temperature inside the freezer compartment measured by the freezer compartment temperature sensor is equal to or lower than a second upper limit temperature and equal to or higher than a second lower limit temperature. In the cooling cycle immediately before the defrost operation, when the temperature inside the freezer compartment measured by the freezer compartment temperature sensor is equal to or lower than the second lower limit temperature and the temperature inside the small refrigerator compartment measured by the small refrigerator compartment temperature sensor is equal to or lower than the first lower limit temperature, the defrost operation is executed. According to the refrigerator of the present invention, since the defrost operation is started when the freezer compartment is equal to or lower than the second lower limit temperature and both the small refrigerator compartments are equal to or lower than the first lower limit temperature, it is possible to prevent the temperature inside the small refrigerator compartment from rising above a certain level.

[0075] In addition, the refrigerator of the present invention further includes a damper provided in an air duct connecting the cooling chamber and the small refrigerator compartment. The arithmetic control unit operates the blower with the damper open before executing the defrost operation. According to the refrigerator of the present invention, by operating the blower with the damper open before executing the defrost operation, the small refrigerator compartment can be further cooled, and an increase in the temperature inside the small refrigerator compartment during the defrost operation can be suppressed.

[0076] In addition, the refrigerator of the present invention is configured to be able to select a mode for preferentially cooling the small refrigerator compartment. When the mode for preferentially cooling the small refrigerator compartment is selected, the arithmetic control unit lowers the set value of the first lower limit temperature in the cooling cycle immediately before the defrost operation. According to the refrigerator of the present invention, when the user selects the mode for preferentially cooling the small refrigerator compartment, by lowering the lower limit temperature in the cooling cycle immediately before the defrost operation, the small refrigerator compartment can be suitably cooled according to the user's request, and furthermore, the energy required for cooling can be reduced.

Description of Reference Numerals

[0077] 10 Refrigerator 11 Heat-insulating Box Body 111 Outer Box 112 Inner box 113 Heat insulation material 115 Cooling chamber 116 Evaporator 117 Heating section 118 Air duct 12 Refrigerating chamber 13 Freezing chamber 14 Machine room 15 Compressor 16 Air outlet 17 Heat insulation wall 18 Heat insulation door 19 Heat insulation door 20 Small refrigerating chamber 21 Storage container 22 Small refrigerating chamber temperature sensor 23 Stored item 24 Timer 25 Blower 26 Arithmetic control unit 27 Freezing chamber temperature sensor 28 Damper 29 Defrost sensor

Claims

1. A refrigerator compartment, A small refrigerator compartment partitioned inside the refrigerator compartment; A small refrigerator compartment temperature sensor that measures the temperature inside the small refrigerator compartment; A cooling chamber in which the air blown into the small refrigerator chamber is cooled by a cooler; A heating unit that defrosts the cooler by heating; a blower that blows the air from the cooling chamber to the refrigeration chamber; A calculation control unit; A mode for preferentially cooling the small refrigerator compartment can be selected, The arithmetic and control unit is When a mode for preferentially cooling the small refrigerator compartment is not selected, a cooling cycle is executed in which the cooler and the blower are operated so that the inside temperature of the small refrigerator compartment measured by the small refrigerator compartment temperature sensor is equal to or lower than a first upper limit temperature and equal to or higher than a first lower limit temperature; The refrigerator is characterized in that, when a mode for preferentially cooling the small refrigerator compartment is selected, a set value of the first lower limit temperature is lowered.

2. The small refrigeration compartment is a chilled compartment, 2. The refrigerator according to claim 1, wherein the mode in which the small refrigerating compartment is cooled preferentially is a freshness-preserving chilling mode in which the chilled compartment is cooled preferentially.

3. The arithmetic and control unit is 2. The refrigerator according to claim 1, wherein the set value of the first lower limit temperature is further reduced in the cooling cycle immediately before a defrosting operation.

4. 3. The refrigerator according to claim 1, wherein a defrosting operation is performed while the mode for preferentially cooling the small refrigerator compartment is being executed.

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