JP5261066B2 - Refrigerator and refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerator-freezer can prevent dew condensation in defrosting, and reduce power consumption. <P>SOLUTION: This refrigerator-freezer includes a refrigerating compartment 2 for refrigerating and storing a stored object, a freezing compartment 4 for freezing and storing a stored object, a first compressor 11 for operating a first freezing cycle 10 in which a first refrigerant is circulated, a first evaporator 14 disposed at a low temperature section of the first freezing cycle 10, and cooling the refrigerating compartment 2, a second compressor 21 for operating a second freezing cycle 20 in which a second refrigerant is circulated, and a second evaporator 24 disposed at a low temperature section of the second freezing cycle 20 for cooling the freezing compartment 4, and the second evaporator 24 is defrosted by heat of a high temperature section of the first freezing cycle 10. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a refrigerator-freezer provided with first and second evaporators for cooling a refrigerator compartment and a freezer compartment, respectively. Moreover, it is related with the refrigerator provided with the 1st, 2nd evaporator which cools the 1st, 2nd cooling chamber from which temperature differs, respectively.

  A conventional refrigerator-freezer is disclosed in Patent Document 1. In this refrigerator-freezer, the refrigerant flows through the compressor and the refrigeration cycle is operated, and the first and second evaporators are arranged in parallel in the low temperature part of the refrigeration cycle. The first evaporator is disposed behind the refrigerator compartment, and the second evaporator is disposed behind the freezer compartment. Cold air generated by heat exchange with the first evaporator circulates in the refrigerator compartment, and the refrigerator compartment is cooled. Moreover, the cool air produced | generated by heat-exchanging with a 2nd evaporator circulates through a freezer compartment, and a freezer compartment is cooled.

  A defrost heater is disposed below each of the first and second evaporators. The first and second evaporators are defrosted by stopping the compressor and driving each defrosting heater.

  Patent Document 2 discloses a refrigerator-freezer that performs defrosting of an evaporator by a refrigeration cycle. In this refrigerator-freezer, an evaporator is disposed in the low temperature part of the refrigeration cycle, and a condenser is disposed in the high temperature part. The condenser is installed on a metal back plate or the like of the refrigerator-freezer, and dissipates heat to the outside air through the back plate by the operation of the refrigeration cycle. The evaporator is cooled by the operation of the refrigeration cycle, and the storage chamber is cooled by the cold air exchanged with the evaporator.

  When the evaporator is defrosted, the refrigerant of the refrigeration cycle is circulated in the reverse direction by the switching means. Thereby, an evaporator is distribute | arranged to the high temperature part of a refrigerating cycle, and it heats up, and defrosting is performed.

JP 2002-122374 A (2nd page-7th page, Fig. 1) Japanese Patent Laid-Open No. 2002-340449 (pages 4 to 5, FIG. 1)

  However, according to the refrigerator-freezer disclosed in Patent Document 1, since the defrosting is performed by raising the temperature of the first and second evaporators using the defrost heater, there is a problem that the power consumption of the refrigerator-freezer increases. Moreover, according to the refrigerator-freezer disclosed by patent document 2, since a defrost heater is not provided, power consumption is reduced. However, the condenser arranged in the high temperature part of the refrigeration cycle is arranged in the low temperature part during defrosting, and there is a problem that condensation occurs on the condenser and the back plate.

  An object of the present invention is to provide a refrigerator-freezer that can prevent condensation during defrosting and reduce power consumption.

  In order to achieve the above object, the refrigerator-freezer of the present invention includes a refrigerating room for storing stored items in a refrigerator, a freezing chamber for storing stored items in a frozen state, and a first compression that operates a first refrigeration cycle through which a first refrigerant flows. A first evaporator that is disposed in a low-temperature part of the first refrigeration cycle and cools the refrigerator compartment, a second compressor that operates a second refrigeration cycle through which a second refrigerant flows, and a second refrigeration cycle And a second evaporator arranged in a low temperature part for cooling the freezer compartment, wherein the second evaporator is defrosted by heat of the high temperature part of the first refrigeration cycle.

  According to this configuration, the first and second refrigeration cycles are operated by the first and second compressors, and the first and second refrigerants are circulated to form the low temperature portion and the high temperature portion of the first and second refrigeration cycles, respectively. Is done. The low temperature and low pressure first refrigerant flows into the first evaporator in the low temperature part of the first refrigeration cycle, and the refrigerator compartment is cooled by the cold air cooled by the first evaporator. The low-temperature and low-pressure second refrigerant flows into the second evaporator in the low-temperature part of the second refrigeration cycle, and the freezer compartment is cooled by the cold air cooled by the second evaporator.

  During the defrosting of the second evaporator, the operation of the second refrigeration cycle is stopped and the first refrigeration cycle is operated. The high temperature part of the first refrigeration cycle and the second evaporator exchange heat, the second evaporator is heated and defrosting is performed.

  Further, the present invention provides a refrigerator with the above-described configuration, wherein the first condenser disposed in the high temperature portion of the first refrigeration cycle, the three-way valve provided on the refrigerant inflow side of the first condenser, and the three-way valve are branched. A defrosting heat exchanger that is arranged in parallel with the first condenser and exchanges heat with the second evaporator, and a check valve provided on the refrigerant outflow side of the defrosting heat exchanger, The three-way valve is switched to the defrosting heat exchanger when defrosting the second evaporator.

  According to this configuration, the flow path of the first refrigerant is switched to the first condenser side by the three-way valve when the refrigerator compartment and the freezer compartment are cooled. As a result, the first and second evaporators are cooled and radiated from the first condenser. At this time, the check valve prevents the first refrigerant from flowing into the defrosting heat exchanger from the refrigerant outflow side of the first condenser. During the defrosting of the second evaporator, the flow path of the first refrigerant is switched to the defrosting heat exchanger side by the three-way valve. Thereby, the first evaporator is cooled and radiated from the defrosting heat exchanger. The second evaporator is heated with heat exchange with the defrosting heat exchanger, and defrosting is performed.

  Further, the present invention is characterized in that, in the refrigerator-freezer configured as described above, the check valve is disposed in the vicinity of a confluence of the refrigerant outflow side of the first condenser and the refrigerant outflow side of the defrosting heat exchanger. . According to this configuration, the check valve and the defrosting heat exchanger are arranged apart from each other. For this reason, when the flow path of the first refrigerant is switched to the first condenser side by the three-way valve, the temperature rise of the second evaporator due to the high-temperature first refrigerant flowing out from the first condenser is reduced.

  Moreover, this invention is a refrigerator-freezer of the said structure, A 2nd evaporator and the said heat exchanger for defrost have the 1st, 2nd refrigerant | coolant pipe | tube through which a 1st, 2nd refrigerant | coolant distribute | circulates, respectively, Two refrigerant tubes are connected by a plurality of fins. According to this structure, the heat | fever of a high temperature 1st refrigerant | coolant is transmitted to a 2nd evaporator via the fin which connects a 1st, 2nd refrigerant pipe.

  Moreover, this invention is a refrigerator-freezer of the said structure, A 2nd evaporator and the said heat exchanger for defrost have the 1st, 2nd refrigerant | coolant pipe | tube through which a 1st, 2nd refrigerant | coolant distribute | circulates, respectively, Two refrigerant pipes are adjacent to each other. According to this structure, the heat | fever of a high temperature 1st refrigerant | coolant is transmitted to a 2nd evaporator via the boundary wall of a 1st, 2nd refrigerant pipe.

  Moreover, the present invention is characterized in that, in the refrigerator-freezer configured as described above, the cross-sectional area of the refrigerant tube of the defrosting heat exchanger is set to be ½ or less of the cross-sectional area of the refrigerant tube of the first evaporator. According to this configuration, the internal volume of the refrigerant pipe of the defrosting heat exchanger is reduced, and a large amount of refrigerant is prevented from accumulating in the defrosting heat exchanger after defrosting.

  Moreover, the present invention is characterized in that, in the refrigerator-freezer configured as described above, the first compressor is stopped for a predetermined period before defrosting the second evaporator. According to this configuration, when the first compressor is stopped and the three-way valve is switched to the defrosting heat exchanger side, the room temperature of the refrigerator compartment rises, and the first compressor is driven when a predetermined period elapses. Thus, the first refrigerant flows through the defrosting heat exchanger, the second evaporator is defrosted, and the refrigerator compartment is cooled. The three-way valve may be switched to the defrosting heat exchanger side after the predetermined period has elapsed.

  Moreover, the refrigerator of the present invention is arranged in the first and second cooling chambers, the first compressor that operates the first refrigeration cycle in which the first refrigerant flows, and the low temperature portion of the first refrigeration cycle, so that the first cooling is performed. A first evaporator that cools the chamber, a second compressor that operates a second refrigeration cycle through which the second refrigerant flows, and a second evaporator that is disposed in a low temperature portion of the second refrigeration cycle and cools the first cooling chamber. And the second evaporator is defrosted by the heat of the high temperature part of the first refrigeration cycle.

  According to the present invention, the first and second compressors operate the first and second refrigeration cycles, respectively, and the first and second evaporators cool the refrigerator compartment and the freezer compartment. The temperature of the evaporator is maintained higher than that of the second evaporator, the cooling efficiency is improved, and the power consumption of the refrigerator-freezer can be reduced.

  Moreover, since the 2nd evaporator of a 2nd freezing cycle is defrosted with the heat | fever of the high temperature part of a 1st freezing cycle, the 1st condenser of a 1st freezing cycle and the 2nd condenser of a 2nd freezing cycle do not become low temperature. . Therefore, dew condensation on the back plate of the refrigerator can be prevented. Further, it is not necessary to separately provide a heater for defrosting the second evaporator, and the temperature rise by the heater or the like during defrosting can be suppressed. Further, most of the heat for heating the second evaporator during defrosting is the heat from the refrigerator compartment, and the refrigerator compartment can be cooled while defrosting. Therefore, power consumption due to defrosting can be suppressed and power consumption of the refrigerator-freezer can be kept low.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing a refrigerator-freezer according to an embodiment. In the refrigerator-freezer 1, a refrigerating room 2 for storing stored items in a refrigerated state is arranged on an upper portion of a heat insulating box 6 that forms a main body. Below the refrigerating room 2, there is provided a vegetable room 3 through a heat insulating wall 7 that is maintained at a temperature higher than that of the refrigerating room 2 and suitable for storing vegetables. Below the vegetable room 3, a freezing room 4 for freezing and storing stored items is arranged via a heat insulating wall 8. The front surface of the refrigerator compartment 2 is opened and closed by a rotating heat insulating door 2a. The front surfaces of the vegetable compartment 3 and the freezer compartment 4 are opened and closed by drawer-type heat insulating doors 3a and 4a integrated with the storage cases 3b and 4b, respectively.

  A machine room 5 is provided behind the freezer room 4. First and second compressors 11 and 21 for operating first and second refrigeration cycles 10 and 20 (see FIG. 2), which will be described in detail later, are disposed in the machine room 5. A first evaporator 14 connected to the first compressor 11 is disposed on the back of the refrigerator compartment 2, and a refrigerator refrigerator 31 is disposed above the first evaporator 14. A second evaporator 24 connected to the second compressor 21 is disposed on the back surface of the freezer compartment 4, and a freezer compartment blower 32 is disposed above the second evaporator 24. A defrost heater 33 is provided below the first evaporator 14.

  Cold air cooled by exchanging heat with the first evaporator 14 is discharged to the refrigerator compartment 2 by the refrigerator fan 31. The cold air flows through the refrigerator compartment 2 and flows into the vegetable compartment 3 communicating with the refrigerator compartment 2. The cold air that has flowed into the vegetable compartment 3 flows through the vegetable compartment 3 and returns to the first evaporator 14. Thereby, the refrigerator compartment 2 and the vegetable compartment 3 are cooled. The cold air cooled by exchanging heat with the second evaporator 24 is discharged into the freezer compartment 4 by the freezer blower 32. The cold air discharged into the freezer compartment 4 flows through the freezer compartment 4 and returns to the second evaporator 24. Thereby, the freezer compartment 4 is cooled.

  FIG. 2 shows the refrigeration cycle of the refrigerator 1. The refrigerator-freezer 1 has a first refrigeration cycle 10 operated by a first compressor 11 and a second refrigeration cycle 20 operated by a second compressor 21. The first refrigeration cycle 10 includes a first condenser 12, a first decompression device 13, and a first evaporator 14 connected by a refrigerant pipe 10a. A first refrigerant such as isobutane flows in the direction of arrow S1 in the refrigerant pipe 10a. That is, the first refrigerant circulates through the first compressor 11, the first condenser 12, the first decompressor 13, the first evaporator 14, and the first compressor 11 in this order.

  A defrosting heat exchanger 18 is arranged in parallel with the first condenser 12. A three-way valve 16 for switching the flow path is provided on the refrigerant inflow side of the first condenser 12, and the refrigerant pipe 10 a branched by the three-way valve 16 is connected to the defrosting heat exchanger 18. A check valve 17 is provided on the refrigerant outflow side of the defrosting heat exchanger 18. The check valve 17 is arranged in the vicinity of the junction 10b between the refrigerant outflow side of the first condenser 12 and the refrigerant outflow side of the defrosting heat exchanger 18, and is arranged away from the defrosting heat exchanger 18.

  By switching the three-way valve 16 to the defrosting heat exchanger 18 side, the first refrigerant flows as indicated by an arrow S1 '. As a result, the first refrigerant circulates through the first compressor 11, the defrosting heat exchanger 18, the first decompressor 13, the first evaporator 14, and the first compressor 11 in this order.

  The second refrigeration cycle 20 operated by the second compressor 21 has a second condenser 22, a second decompression device 23, and a second evaporator 24 connected by a refrigerant pipe 20a. A second refrigerant such as isobutane flows in the direction of the arrow S2 in the refrigerant pipe 20a. That is, the second refrigerant circulates through the second compressor 21, the second condenser 22, the second pressure reducing device 23, the second evaporator 24, and the second compressor 21 in this order.

  The defrosting heat exchanger 18 and the second evaporator 24 are formed so as to be able to exchange heat with each other. FIG. 3 is a detailed view of the defrosting heat exchanger 18 and the second evaporator 24. The first and second refrigerant pipes 10 a and 20 a of the defrosting heat exchanger 18 and the second evaporator 24 meander and are close to each other, and are connected by a large number of fins 34. Thereby, heat exchange between the defrosting heat exchanger 18 and the second evaporator 24 is easily performed via the fins 34. The first and second refrigerant pipes 10 a and 20 a may be provided adjacent to each other so as to be able to exchange heat with each other via a boundary wall between the defrosting heat exchanger 18 and the second evaporator 24.

  Further, the cross-sectional area of the first refrigerant pipe 10 a of the defrosting heat exchanger 18 is formed to be ½ or less of the cross-sectional area of the first refrigerant pipe 10 a of the first evaporator 14. Thereby, when the three-way valve 16 is switched to the first condenser 12 side, the amount of the first refrigerant remaining in the defrosting heat exchanger 18 can be reduced.

  The first and second condensers 12 and 22 are provided by being joined to the back side of a metal plate (not shown) that covers the side surface and the back surface of the refrigerator 1. The first and second condensers 12 and 22 extend in the heat insulating box 6 and are arranged in the vicinity of the doors 2a, 3a, and 4a of the heat insulating walls 7 and 8. Thereby, while ensuring sufficient heat dissipation area, the dew condensation of door 2a, 3a, 4a vicinity can be prevented.

  The first and second refrigeration cycles 10 and 20 are provided with first and second internal heat exchangers 15 and 25, respectively. The first internal heat exchanger 15 is adjacent to the heat exchange unit 15a disposed at the rear stage of the first condenser 12 and the heat exchange unit 15b disposed at the rear stage of the first evaporator 14, and mutually passes through a boundary wall. It is formed to be heat exchangeable. The high temperature first refrigerant that has flowed out of the first condenser 12 flows through the heat exchange unit 15a, and the low temperature first refrigerant that flows out of the first evaporator 14 flows through the heat exchange unit 15b. When the first pressure reducing device 13 is formed of a capillary tube, the heat exchanging unit 15a may also serve as the first pressure reducing device 13.

  The second internal heat exchanger 25 is adjacent to the heat exchange unit 25a disposed in the subsequent stage of the second condenser 22 and the heat exchange unit 25b disposed in the subsequent stage of the second evaporator 24, and is mutually connected via a boundary wall. It is formed to be heat exchangeable. The high-temperature second refrigerant that has flowed out of the second condenser 22 flows through the heat exchange unit 25a, and the low-temperature second refrigerant that flows out of the second evaporator 24 flows through the heat exchange unit 25b. In the case where the second decompression device 23 is made of a capillary tube, the heat exchanging portion 25a may also serve as the second decompression device 23.

  In the refrigerator 1 having the above configuration, when the refrigerator compartment 2, the vegetable compartment 3 and the freezer compartment 4 are cooled, the first and second compressors 11 and 21 drive the refrigerant pipes 10a and 20a so that the first and second refrigerants circulate. . The first and second compressors 11 and 21 compress the first and second refrigerants to high temperature and high pressure, and the first and second decompression devices 13 and 23 decompress and expand the first and second refrigerants at low temperature and low pressure. To.

  Accordingly, the first and second refrigeration cycles 10 and 20 until the first and second refrigerants flow out of the first and second compressors 11 and 21 and flow into the first and second decompression devices 13 and 23. It becomes the high temperature part. The low temperature of the first and second refrigeration cycles 10 and 20 until the first and second refrigerant flows out of the first and second decompression devices 13 and 23 and flows into the first and second compressors 11 and 21. Part.

  The first high-temperature and high-pressure first refrigerant compressed by the first compressor 11 is deprived of heat by the first condenser 12 and condensed. The first refrigerant flowing out of the first condenser 12 is prevented from flowing into the defrosting heat exchanger 18 by the check valve 17. At this time, the check valve 17 is arranged away from the defrosting heat exchanger 18 and in the vicinity of the junction 10b. For this reason, the temperature increase of the second evaporator 24 due to heat transfer from the high-temperature first refrigerant flowing out from the first condenser 12 through the first refrigerant pipe 10a can be reduced.

  The first refrigerant liquefied by the first condenser 12 flows into the first internal heat exchanger 15, exchanges heat with the first refrigerant that flows out of the first evaporator 14, and is further cooled. The first refrigerant in the liquid state cooled by the first internal heat exchanger 15 and having a high degree of supercooling flows into the first decompression device 13. The first refrigerant is decompressed and expanded by the first decompression device 13, and becomes a low-temperature wet steam having a low dryness.

  The first refrigerant that has become low-temperature wet steam flows into the first evaporator 14, takes heat from the cold air in the refrigerator compartment 2, evaporates, and becomes wet steam with higher dryness. The first refrigerant in the wet vapor state flowing out of the first evaporator 14 flows into the first internal heat exchanger 15 and evaporates while taking heat from the high-temperature first refrigerant flowing out of the first condenser 12, and is superheated steam. It becomes. The first refrigerant that has become superheated steam returns to the first compressor 11. Thereby, a 1st refrigerant | coolant circulates, the 1st freezing cycle 10 is drive | operated, and the refrigerator compartment 2 and the vegetable compartment 3 are cooled.

  The high-temperature and high-pressure second refrigerant compressed by the second compressor 21 is condensed by being deprived of the ambient air by the second condenser 22. The second refrigerant liquefied by the second condenser 22 flows into the second internal heat exchanger 25, exchanges heat with the second refrigerant that flows out of the second evaporator 24, and is further cooled. The second refrigerant in a liquid state cooled by the second internal heat exchanger 25 and having a high degree of supercooling flows into the second decompression device 23. The second refrigerant is decompressed and expanded by the second decompression device 13, and becomes low-temperature wet steam having a low dryness.

  The second refrigerant that has become low-temperature wet steam flows into the second evaporator 24, takes heat from the cold air in the freezer compartment 4 and evaporates to become wet steam with higher dryness. The second refrigerant in the wet vapor state flowing out from the second evaporator 24 flows into the second internal heat exchanger 25, evaporates while taking heat from the high-temperature second refrigerant flowing out from the second condenser 22, and superheated steam. It becomes. The second refrigerant that has become superheated steam returns to the second compressor 21. As a result, the second refrigerant circulates, the second refrigeration cycle 10 is operated, and the freezer compartment 4 is cooled.

  FIG. 4 is a flowchart showing the operation of the second evaporator 24 during defrosting. In step # 11, the second compressor 21 is stopped to defrost the second evaporator 24. In step # 12, the first compressor 11 is stopped. In step # 13, the three-way valve 16 is switched to the defrosting heat exchanger 18 side.

  In step # 14, the process waits until a predetermined time elapses after the first compressor 11 is stopped. Thereby, the temperature of the refrigerator compartment 2 and the vegetable compartment 3 rises. When the predetermined time has elapsed and the refrigerator compartment 2 and the vegetable compartment 3 are close to the upper limit of the set temperature, the process proceeds to step # 15. The three-way valve 16 may be switched to the defrosting heat exchanger 18 side after the predetermined time has elapsed. Further, the waiting period may not depend on time. That is, a temperature sensor may be provided in the refrigerator compartment 2 or the vegetable compartment 3, and after waiting for a predetermined period until the upper limit of the set temperature is detected by the temperature sensor, the process may proceed to step # 15.

  In step # 15, the first compressor 11 is driven. Thereby, the 1st freezing cycle 10 is drive | operated and the 2nd evaporator 24 is heated up by heat exchange with the heat exchanger 18 for a defrost of a high temperature part, and a defrost is performed. Moreover, the refrigerator compartment 2 and the vegetable compartment 3 are cooled. By preheating the refrigerator compartment 2 and the vegetable compartment 3 in step # 14, overcooling of the refrigerator compartment 2 and the vegetable compartment 3 at the time of defrosting can be prevented.

  In step # 16, the process waits until a predetermined time elapses. Thereby, defrosting of the 2nd evaporator 24 advances, and when predetermined time passes and defrosting is completed, it will transfer to Step # 17. In step # 17, the three-way valve 16 is switched to the first condenser 12 side. In step # 18, the process waits until a predetermined time elapses. The first compressor 11 may be temporarily stopped when the three-way valve 16 is switched. Alternatively, the three-way valve 16 may be switched to the first condenser 12 side after the predetermined time has elapsed.

  When the predetermined time has elapsed, the process proceeds to step # 19 and the second compressor 21 is driven. Thereby, the 2nd freezing cycle 20 is drive | operated and the freezer compartment 4 is cooled.

  The first evaporator 14 that cools the refrigerator compartment 2 has a higher temperature than the second evaporator 24, and therefore has a smaller amount of frost formation than the second evaporator 24. Moreover, the temperature of the air in the refrigerator compartment 2 is 0 degreeC or more. Accordingly, the first evaporator 14 can be defrosted by the heat of the air in the refrigerator compartment 2 simply by stopping the first compressor 11 and operating the refrigerator compartment fan 31. For this reason, the defrost heater 33 is not normally driven, but is driven at the time of abnormal frost formation.

  According to the present embodiment, the first and second refrigeration cycles 10 and 20 are operated by the first and second compressors 11 and 21, respectively, and the refrigerator 2 and the freezer compartment 4 are connected by the first and second evaporators 14 and 24, respectively. Since it cools, the temperature of the 1st evaporator 14 which cools the refrigerator compartment 2 can be maintained higher than the 2nd evaporator 24, cooling efficiency improves, and the power consumption of the refrigerator-freezer 1 can be reduced.

  Further, since the second evaporator 24 of the second refrigeration cycle 20 is defrosted by the heat of the high temperature portion of the first refrigeration cycle 10, the first condenser 12 of the first refrigeration cycle 10 and the second of the second refrigeration cycle 20 are defrosted. The condenser 22 does not become low temperature. Therefore, dew condensation on the side and back of the refrigerator-freezer 1 can be prevented. Moreover, it is not necessary to separately provide a heater for defrosting the second evaporator 22, and the temperature rise by the heater or the like during defrosting can be suppressed. Therefore, the power consumption by defrosting can be suppressed and the power consumption of the refrigerator-freezer 1 can be kept low.

  In addition, the first condenser 12 and the defrosting heat exchanger 18 are arranged in parallel, and the three-way valve 16 and the check valve 17 are provided on the refrigerant inflow side and the refrigerant outflow side, respectively. The refrigerator-freezer 1 which defrosts the 2nd evaporator 24 of the 2nd freezing cycle 20 with the heat of a part can be easily implement | achieved.

  Further, since the check valve 17 is disposed in the vicinity of the junction 10a away from the defrosting heat exchanger 18, heat transfer from the high-temperature first refrigerant flowing out from the first condenser 12 through the first refrigerant pipe 10a. Therefore, the temperature rise of the second evaporator 24 can be reduced. Therefore, the cooling efficiency of the refrigerator-freezer 1 can be improved.

  Moreover, since the 1st compressor 11 was stopped for the predetermined period before the defrost of the 2nd evaporator 24, the refrigerator compartment 2 and the vegetable compartment 3 were heated beforehand, and the excess of the refrigerator compartment 2 and the vegetable compartment 3 at the time of a defrost was carried out. Cooling can be prevented.

  Further, since the cross-sectional area of the first refrigerant pipe 10a of the defrosting heat exchanger 18 is formed to be ½ or less of the cross-sectional area of the first refrigerant pipe 10a of the first evaporator 14, After the defrosting is completed and the three-way valve 16 is switched to the first condenser 12 side, a large amount of the first refrigerant does not remain in the defrosting heat exchanger 18. Therefore, the amount of refrigerant sealed in the first refrigeration cycle 10 can be suppressed.

  The same applies to any refrigerator provided with the first and second refrigeration cycles in which the first and second evaporators 14 and 24 are disposed in the first and second cooling chambers having different indoor temperatures. It can be applied to. In other words, the present invention can be applied to refrigeration cycle application equipment centered on a domestic refrigerator-freezer 1.

  According to this invention, it can utilize for the refrigerator refrigerator provided with the 1st, 2nd evaporator which cools a refrigerator compartment and a freezer compartment, respectively. Moreover, it can utilize for the refrigerator provided with the 1st, 2nd evaporator which cools the 1st, 2nd cooling chamber from which temperature differs, respectively.

Side surface sectional drawing which shows the refrigerator-freezer of embodiment of this invention The figure which shows the refrigerating cycle of the refrigerator-freezer of embodiment of this invention. Detailed drawing which shows the heat exchanger for defrosting of the refrigerator-freezer of embodiment of this invention, and a 2nd evaporator. The flowchart which shows the operation | movement at the time of the defrosting of the 2nd evaporator of the refrigerator-freezer of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Refrigerated refrigerator 2 Refrigerated room 3 Vegetable room 4 Freezer room 10 1st freezing cycle 10a 1st refrigerant pipe 11 1st compressor 12 1st condenser 13 1st decompression device 14 1st evaporator 15 1st internal heat exchanger 16 Three-way valve 17 Check valve 18 Defrosting heat exchanger 20 Second refrigeration cycle 20a Second refrigerant pipe 21 Second compressor 22 Second condenser 23 Second decompression device 24 Second evaporator 25 Second internal heat exchanger 31 Refrigeration room blower 32 Freezer room blower 33 Defrost heater 34 Fin

Claims (7)

It is arranged in a cold room for storing stored items in a refrigerator, a freezing chamber for storing stored items in a frozen state, a first compressor for operating a first refrigeration cycle through which a first refrigerant flows, and a low temperature part of the first refrigeration cycle. A first evaporator that cools the refrigerator compartment, a second compressor that operates a second refrigeration cycle through which a second refrigerant flows, and a second compressor that is disposed in a low temperature part of the second refrigeration cycle and cools the freezer compartment. An evaporator, a first condenser disposed in a high temperature part of the first refrigeration cycle, a three-way valve provided on the refrigerant inflow side of the first condenser, and the three-way valve branches in parallel with the first condenser A defrosting heat exchanger that exchanges heat with the second evaporator and a check valve provided on the refrigerant outflow side of the defrosting heat exchanger, the three-way valve for the defrosting heat by the defrosting child a second evaporator of the high-temperature portion of the first refrigeration cycle by switching on the heat exchanger side Refrigerator according to claim. 2. The refrigerator-freezer according to claim 1 , wherein the check valve is disposed in the vicinity of a confluence of the refrigerant outflow side of the first condenser and the refrigerant outflow side of the defrosting heat exchanger. The second evaporator and the defrosting heat exchanger have first and second refrigerant pipes through which the first and second refrigerants circulate, respectively, and the first and second refrigerant pipes are connected by a plurality of fins. The refrigerator-freezer according to claim 1 , wherein the refrigerator is a refrigerator. The second evaporator and the heat exchanger for defrosting have first and second refrigerant tubes through which the first and second refrigerants circulate, respectively, and the first and second refrigerant tubes are adjacent to each other. The refrigerator-freezer of Claim 1 or Claim 2 . Refrigerator according to claim 1 or claim 2, characterized in that the cross-sectional area of the refrigerant tubes of the heat exchanger for the defrosting to 1/2 or less of the cross-sectional area of the refrigerant tubes of the first evaporator. The refrigerator-freezer according to any one of claims 1 to 5 , wherein the first compressor is stopped for a predetermined period before defrosting the second evaporator. First and second cooling chambers, a first compressor that operates a first refrigeration cycle through which a first refrigerant flows, and a first evaporator that is disposed in a low temperature portion of the first refrigeration cycle and cools the first cooling chamber When, a second compressor to operate the second refrigeration cycle in which the second refrigerant flows, and a second evaporator for cooling the second cooling chamber is arranged in the cold section of the second refrigeration cycle, the first refrigeration cycle A first condenser disposed in the high-temperature section, a three-way valve provided on the refrigerant inflow side of the first condenser, a branching by the three-way valve, and a second evaporator disposed in parallel with the first condenser; A defrosting heat exchanger for performing heat exchange, and a check valve provided on the refrigerant outflow side of the defrosting heat exchanger, and switching the three-way valve to the defrosting heat exchanger side The refrigerator which defrosts a 2nd evaporator with the heat | fever of the high temperature part of 1 freezing cycle.

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