JP2014020736A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerator capable of reducing power consumption.SOLUTION: The refrigerator comprises: a first storage room 5 for cold-storing a stored object; a second storage room 4 for frozen-storing a stored object; a cold air passage 7 in which a blower is arranged and cold air is circulated in a vertical direction; and an evaporator 30 arranged in the cold air passage 7 and generating the cold air. The evaporator 30 has: a first cooling section 31 arranged at a rear part of the cold air passage 7, and formed of micro-tubes formed by parting a flat pipe 34 into plural fine passages in which a refrigerant is circulated; and a second cooling section 36 arranged at a front part of the cold air passage 7 adjacent to the first cooling section 31, and formed by adhering multiple fins 37 to a refrigerant pipe 21. The cold air flowing from the first storage room 5 is introduced to the rear part of the cold air passage 7, and the cold air flowing from the second storage room 4 is introduced to the front part of the cold air passage 7.

Description

  The present invention relates to a refrigerator provided with an evaporator.

  A conventional refrigerator is disclosed in Patent Document 1. This refrigerator is provided with a refrigerator compartment, a vegetable compartment, and a freezer compartment in a heat insulating box. The refrigerator compartment and the vegetable compartment store the stored items in a refrigerator, and the freezer compartment stores the stored items in a frozen state. A cool air passage through which cool air flows is arranged at the rear of the heat insulation box. A blower is disposed above the cool air passage, and an evaporator is disposed below the blower. In addition, a defrosting heater for defrosting when the evaporator is frosted is disposed below the cold air passage.

  The evaporator is formed in a fin tube type in which a large number of fins are fixed to a refrigerant pipe through which the refrigerant flows, and is arranged in a plurality of stages in the vertical direction by meandering of the refrigerant pipe. The fins at the bottom of the evaporator are formed with a short depth and are arranged rearwardly. Thereby, a frosting space is formed in front of the lower part of the evaporator.

  In the refrigerator having the above configuration, cold air generated by exchanging heat with the evaporator by driving the blower flows through the cold air passage. Cold air is discharged to the refrigerator compartment, vegetable compartment and freezer compartment, respectively, and cools each storage compartment. And the cold air which flowed out from each store room is returned below the evaporator of a cold passage.

  Since the cold air flowing through the cold air passage flows through the storage chamber and contains moisture, the evaporator forms frost due to the solidification of moisture during heat exchange. At this time, since a frosting space is provided in the lower part of the evaporator, clogging due to frosting of the evaporator is reduced. Thereby, the air volume of the cool air discharged to each store room can be secured, and the number of defrosting times by the defrosting heater can be reduced.

Japanese Patent No. 4895958 (pages 4 to 10, FIG. 6)

  However, according to the conventional refrigerator, clogging at the bottom of the evaporator is suppressed, but clogging due to frost occurs above the bottom of the evaporator. For this reason, there existed a problem that a defrosting interval is still short and the power consumption of a refrigerator is large.

  An object of this invention is to provide the refrigerator which can reduce power consumption.

  In order to achieve the above object, the present invention provides a first storage chamber for storing stored items in a refrigerator, a second storage chamber for storing stored items in a frozen state, a cold air passage through which a cooler flows in a vertical direction by arranging a blower. A refrigerator including an evaporator disposed in the cold air passage to generate cold air, wherein the evaporator is disposed at a rear portion of the cold air passage and is partitioned into a plurality of narrow passages through which a refrigerant flows in a flat tube A first cooling section formed by a tube; and a second cooling section that is disposed adjacent to the first cooling section at the front portion of the cold air passage and is formed by fixing a number of fins to the refrigerant pipe. The cold air flowing out from the first storage chamber is guided to the rear part of the cold air passage, and the cold air flowing out from the second storage chamber is guided to the front part of the cold air passage.

  According to this configuration, the cold air flowing out from the first storage chamber for storing the stored items in a refrigerated state is guided to the rear part of the cold air passage and exchanges heat with the first cooling unit formed by the microtube. The cold air flowing out from the second storage chamber for freezing and storing the stored material is guided to the front portion of the cold air passage, and exchanges heat with the fin-tube-type second cooling portion. Since the cold air that flows through the first storage chamber and contains a large amount of water exchanges heat with the first cooling unit that is not provided with fins, clogging due to frosting of the first cooling unit is suppressed. Since the second cooling unit circulates through the second storage chamber and exchanges heat with cold air having little moisture, frost formation is suppressed. In addition, since the second cooling unit has a large heat exchange area due to the fins, low-temperature cold air can be generated by heat exchange even when frost with low thermal conductivity is formed.

  In the refrigerator having the above-described configuration, the plurality of flat tubes are connected in parallel between an inflow tube and an outflow tube in which the first cooling portion extends vertically and the refrigerant flows, and the flat tubes are connected to the thin tube. The passage is arranged in contact with the second cooling section so that the passages are arranged in the vertical direction.

  According to this configuration, the refrigerant flowing through the inflow pipe branches into a plurality of flat pipes and flows through the narrow passages in each flat pipe, and then merges to flow through the outflow pipe. The inside of the cold air passage is partitioned in the front-rear direction by a plate-like flat tube, and the cold air that exchanges heat with the first cooling unit and the cold air that exchanges heat with the second cooling unit are separated and circulated.

  Moreover, the present invention is characterized in that, in the refrigerator having the above-described configuration, the flat tube meanders in a horizontal plane, and an air flow path is formed between the back wall of the cold air passage and the first cooling part. According to this configuration, heat exchange is performed between the cold air flowing between the meandering flat tubes and the air flow path behind the first cooling unit and the first cooling unit.

  Moreover, the present invention is characterized in that in the refrigerator configured as described above, the outlet of the cold air flowing out from the second storage chamber is arranged facing the second cooling section. According to this configuration, the cold air flowing out from the second storage chamber through the outlet facing the second cooling part flows through the front part of the cold air passage and exchanges heat with the second cooling part.

  Moreover, this invention is a refrigerator of the said structure. WHEREIN: It arrange | positions under the 2nd cooling part, The defrost heater which defrosts the said evaporator, and the heater cover which covers the upper direction of the said defrost heater are provided, 1st storage Cold air flowing out of the chamber passes through the lower part of the defrosting heater and is guided to the lower part of the first cooling unit.

  According to this configuration, the cold air that has flowed out of the first storage chamber passes through the lower portion of the defrost heater and flows through the rear portion of the cold air passage to exchange heat with the first cooling portion. When the evaporator is frosted, the defrost heater is driven to defrost the evaporator.

  In the refrigerator having the above-described configuration, the present invention provides a compressor that operates a refrigeration cycle, a condenser connected to the compressor, and a first expander disposed between the condenser and the evaporator. A first switching passage branched from between the compressor and the condenser and connected between the first cooling part and the second cooling part, and branched from between the condenser and the expander. And a second switching passage connected between the first cooling section and the second cooling section, and the refrigerant discharged from the compressor flows in the order of the condenser, the first expander, and the evaporator. Then, cold air is generated by heat exchange with the evaporator, and the refrigerant discharged from the compressor passes through the first switching passage, the first cooling portion, the first expander, the second switching passage, and the second cooling portion. A hot gas defrosting operation is performed at a predetermined time in which the first cooling unit is defrosted by the condensation of the refrigerant in sequence. It is characterized in that.

  According to this configuration, the refrigeration cycle is operated by driving the compressor. When each storage chamber is cooled, the high-temperature refrigerant discharged from the compressor is condensed while releasing heat from the condenser. The high-temperature refrigerant expands in the first expander, becomes low-temperature and low-pressure, and is sent to the evaporator. The refrigerant flowing into the evaporator exchanges heat with the cold air flowing through the cold air passage, evaporates while absorbing heat, and is sent to the compressor as a low-temperature gas refrigerant. When the first cooling section is frosted, the hot gas defrosting operation is performed by switching the refrigerant flow path. The high-temperature refrigerant discharged from the compressor flows through the first switching passage and condenses while dissipating heat in the first cooling section. Thereby, defrosting of the 1st cooling part is performed. The high-temperature refrigerant expands in the first expander to become low-temperature and low-pressure, and is sent to the second cooling unit through the second switching passage. Thereby, a 2nd cooling part is maintained at low temperature, and a low temperature gas refrigerant is sent to a compressor.

  According to the present invention, in the refrigerator configured as described above, a second expander is provided between the first expander and the condenser, and the second switching passage branches from between the first expander and the second expander. After the refrigerant flows in parallel through the path through the first switching passage, the first cooling unit and the first expander and the path through the condenser and the second expander during the hot gas defrosting operation, It is characterized by doing.

  According to this configuration, when the hot gas defrosting operation is performed, the high-temperature refrigerant discharged from the compressor branches into the condenser and the first switching passage, and condenses while releasing heat in the condenser and the first cooling unit. . Thereby, defrosting of the 1st cooling part is performed. The high-temperature refrigerant expands in the first expander and the second expander to become low temperature and low pressure, merges in the second switching passage, and is sent to the second cooling unit. Thereby, a 2nd cooling part is maintained at low temperature, and a low temperature gas refrigerant is sent to a compressor.

  According to the present invention, the evaporator has the first cooling part formed by the microtube and the second cooling part in which the fin is fixed to the refrigerant pipe, and the cold air flowing out from the first storage chamber arranges the first cooling part. The cool air that has been guided to the rear of the cool air passage and has flowed out of the second storage chamber is guided to the front of the cool air passage in which the second cooling section is arranged. As a result, cold air with a high amount of water exchanges heat with the first cooling unit where fins are not provided, and the cold air with a low amount of water exchanges heat with the second cooler, and clogging of the evaporator due to frost formation is suppressed. Therefore, the power consumption of the refrigerator can be reduced by lengthening the defrosting interval of the evaporator.

Side surface sectional drawing which shows the refrigerator of 1st Embodiment of this invention. The front view which shows the evaporator of the refrigerator of 1st Embodiment of this invention. The top view which shows the evaporator of the refrigerator of 1st Embodiment of this invention. The right view which shows the evaporator of the refrigerator of 1st Embodiment of this invention. Sectional drawing which shows the microtube of the evaporator of the refrigerator of 1st Embodiment of this invention Side surface sectional drawing which shows the detail of the evaporator vicinity of the refrigerator of 1st Embodiment of this invention The circuit diagram which shows the refrigerating cycle of the refrigerator of 1st Embodiment of this invention. The circuit diagram which shows the refrigerating cycle of the refrigerator of 2nd Embodiment of this invention.

<First Embodiment>
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing the refrigerator of the first embodiment. The refrigerator 1 is provided with a refrigerator compartment 3, a freezer compartment 4, and a vegetable compartment 5 in order from above the heat insulating box 2. The refrigerator compartment 3 stores the stored items in a refrigerator, and the freezer compartment 4 stores the stored items in a frozen state. The vegetable room 5 is maintained at a higher temperature than the refrigerated room 3 and refrigerates stored items such as vegetables.

  The refrigerator compartment 3 is opened and closed by a pivotable door 3a pivoted at one end. The freezer compartment 4 and the vegetable compartment 5 are opened and closed by drawer type doors 4a and 5a formed integrally with a storage case (not shown), respectively.

  Cold air passages 7 and 8 communicating with each other via a damper 15 are provided on the back surfaces of the freezer compartment 4 and the refrigerator compartment 3. A blower 12 that distributes cool air is disposed in the cool air passage 7. Below the blower 12, an evaporator 30 for generating cold air is disposed. A defrost heater 16 that performs defrosting of the evaporator 30 is disposed below the evaporator 30. The upper surface of the defrost heater 16 is covered with a heater cover 17. The heater cover 17 prevents the defrost heater 16 from being broken due to the defrost water dripping onto the defrost heater 16.

  The cold air passage 7 has an outlet 7 a for discharging cold air to the freezer compartment 4 and an outlet 7 b for discharging cold air from the freezer compartment 4. In the cold air passage 8, a discharge port 8 a for discharging cold air to the refrigerator compartment 3 is opened. In addition, a communication path (not shown) that connects the refrigerator compartment 3 and the vegetable compartment 5 is provided. The vegetable compartment 5 has an outlet 7c through which cold air flows out.

  A machine room 6 is provided behind the vegetable room 5, and a compressor 22 is installed in the machine room 6. The refrigerant flows through the refrigerant pipe 21 (see FIG. 7) by driving the compressor 22, and the refrigeration cycle 20 (see FIG. 7) is operated.

  When the blower 12 is driven, the cold air that has exchanged heat with the evaporator 30 flows through the cold air passage 7. At this time, when the damper 15 is opened, cold air flows through the cold air passage 8. The cold air flowing through the cold air passage 7 and the cold air passage 8 is discharged into the freezer compartment 4 and the refrigerator compartment 3 through the discharge ports 7a and 8a, respectively.

  The cold air discharged from the discharge port 7a circulates in the freezer compartment 4 to cool the stored item, and returns to the cold air passage 7 through the outlet port 7b. The cold air discharged from the discharge port 8a circulates in the refrigerator compartment 3 to cool the stored items, and flows into the vegetable compartment 5 through the communication path. The cold air that has flowed into the vegetable compartment 5 flows through the vegetable compartment 5 to cool the stored items, and returns to the cold air passage 7 through the outlet 7c.

  2, 3 and 4 show a front view, a top view and a right side view of the evaporator 20, respectively. The evaporator 30 includes a first cooling unit 31 and a second cooling unit 36 that are adjacent to each other in the front-rear direction. The first cooling unit 31 is disposed in the rear part of the cold air passage 7 (see FIG. 1), and the second cooling unit 36 is disposed in the front part of the cold air passage 7. As will be described in detail later, the first cooling unit 31 mainly cools the cold air returning from the vegetable compartment 5 to the cold air passage 7, and the second cooling portion 36 mainly cools the cold air returning from the freezer compartment 4 to the cold air passage 7.

  The first cooling unit 31 is formed of a microtube, and a plurality of flat tubes 34 are connected in parallel in the vertical direction between an inflow tube 32 and an outflow tube 33 that extend in the vertical direction. FIG. 5 shows a cross-sectional view of the flat tube 34. The flat tube 34 is partitioned into a plurality of narrow passages 35 through which the refrigerant flows, and the narrow passages 35 are arranged in one direction. The first cooling part 31 made of a microtube is branched into a plurality of narrow passages 35 having a small cross-sectional area so that the refrigerant is circulated. For this reason, the 1st cooling part 31 can obtain a desired heat exchange amount with a small volume, and space saving of the 1st cooling part 31 can be achieved.

  The flat tubes 34 are arranged in contact with the second cooling unit 36 with the juxtaposed direction of the narrow passages 35 arranged in the vertical direction. As a result, the inside of the cold air passage 7 (see FIG. 1) is partitioned forward and backward by the flat tubes 34 arranged vertically, and the cold air is separated forward and backward. Further, the flat tube 34 is formed by meandering in a U shape in a horizontal plane. Thereby, between the flat tubes 34 which oppose, cold air distribute | circulates upwards from the downward direction, and is heat-exchanged.

  The second cooling part 36 is formed in a fin tube type in which a large number of thin plate-like fins 37 are fixed to the refrigerant pipe 21 meandering in the vertical direction. Thereby, when the cold air which has circulated through the freezer compartment 4 and cooled the stored material returns to the cold air passage 7 via the outlet 7b, the inside of the second cooling part 36 can be smoothly circulated from the front to the upper side. . Moreover, by forming the 2nd cooling part 36 in a fin tube type, production cost can be held down rather than the case where it forms with a micro tube.

  FIG. 6 is a side sectional view showing details in the vicinity of the evaporator 30. The second cooling unit 36 faces the outflow port 7 b of the freezer compartment 4 and is disposed in the front part of the cool air passage 7. The defrosting heater 16 and the heater cover 17 are arranged below the second cooling unit 36 so as to be biased toward the front part of the cold air passage 7. The outlet 7 c of the vegetable room 5 is provided below the defrost heater 16. Further, a space 7 d that forms an air flow path is provided between the back wall of the cold air passage 7 and the first cooling unit 31.

  As shown by the arrow A1, the cold air flowing out from the vegetable compartment 5 through the outlet 7c is guided to the rear part of the cold air passage 7 by the heater cover 17 and the defrosting heater 16. Then, as indicated by an arrow A 2, the cold air mainly flows between the flat tubes 34 facing each other of the first cooling unit 31 and the space 7 d (air flow path) and exchanges heat with the first cooling unit 31. By providing the space 7d, the heat exchange area between the first cooling unit 31 and the cold air can be further increased.

  As shown by the arrow B1, the cold air flowing out from the freezer compartment 4 through the outlet 7b is guided to the second cooling part 36 facing the outlet 7b. Then, as indicated by an arrow B <b> 2, the cold air circulates mainly in the front part of the cold air passage 7 partitioned by the flat tube 34 of the first cooling part 31 and exchanges heat with the second cooling part 36.

  The cold air exchanged with the first cooling unit 31 and the second cooling unit 36 merges above the evaporator 30 and is guided to the discharge ports 7a and 8a (see FIG. 1).

  FIG. 7 is a circuit diagram showing the refrigeration cycle 20 of the refrigerator 1. A condenser 23, an expander 24, a first cooling unit 31 of the evaporator 30, and a second cooling unit 36 of the evaporator 30 are sequentially connected to the compressor 22 via a refrigerant pipe 21 through which the refrigerant flows. Return to. The inflator 24 (first inflator) is formed by a capillary tube.

  A switching valve 27 a is provided between the compressor 22 and the condenser 23. A switching valve 27 b is provided between the condenser 23 and the expander 24. A switching valve 27 c is provided between the first cooling unit 31 and the second cooling unit 36. The switching valves 27 a and 27 c are connected by a switching passage 28 including a refrigerant pipe 21. A switching passage 29 including the refrigerant pipe 21 is led out from the switching valve 27 b and connected between the switching valve 27 c and the second cooling unit 36 via the check valve 26.

  The refrigeration cycle 20 is driven by driving the compressor 22, and the refrigerant flows in the direction indicated by the arrow S1 (shown in white in the figure) by switching the switching valves 7a, 7b, and 7c when each storage chamber is cooled. The high-temperature and high-pressure refrigerant compressed by the compressor 22 is condensed while dissipating heat in the condenser 23. The high-temperature refrigerant expands in the expander 24 to become low-temperature and low-pressure and is sent to the evaporator 30. The refrigerant flowing into the evaporator 30 exchanges heat with the cold air flowing through the cold air passage 7, evaporates while absorbing heat, and is sent to the compressor 22 as a low-temperature gas refrigerant. Thereby, the refrigerant circulates to operate the refrigeration cycle 20, and cold air is generated by the airflow exchanged with the evaporator 30.

  The refrigerator 1 performs a hot gas defrosting operation and a heater defrosting operation for defrosting the evaporator 30 at a predetermined time. In the heater defrosting operation, the evaporator 30 is defrosted by the defrosting heater 16 (see FIG. 6). In the hot gas defrosting operation, the first cooling unit 31 is mainly defrosted by the refrigeration cycle 20.

  As described above, the first cooling section 31 mainly exchanges heat with the cold water with a large amount of water returning from the vegetable compartment 5 to the cold air passage 7, and the second cooling section 36 with the cold air with a small amount of water returning from the freezer compartment 4 to the cold air passage 7. Mainly heat exchange. For this reason, the 1st cooling part 31 which frosts more easily than the 2nd cooling part 36 is defrosted by hot gas defrosting operation, the temperature rise of the 2nd cooling part 36 is suppressed, and clogging by frost formation is prevented. be able to.

  During the hot gas defrosting operation, the blower 12 is stopped, and the refrigerant flows in the direction indicated by the arrow S2 (shown in black in the drawing) by switching the switching valves 7a, 7b, and 7c. The high-temperature and high-pressure refrigerant compressed by the compressor 22 flows through the switching passage 26 and condenses while radiating heat in the first cooling unit 31. Thereby, the 1st cooling part 31 is defrosted. The high-temperature refrigerant expands in the expander 24 to become low-temperature and low-pressure, and is sent to the second cooling unit 36 via the switching passage 29. The refrigerant flowing into the second cooling unit 36 exchanges heat with the cold air in the cold air passage 7, evaporates while absorbing heat, and is sent to the compressor 22 as a low-temperature gas refrigerant.

  At this time, since the 2nd cooling part 36 is maintained at low temperature, the temperature rise in the freezer compartment 4 is prevented. Moreover, since the back surface of the 2nd cooling part 36 touches the 1st cooling part 31, the defrost of the rear part of the 2nd cooling part 36 which is easy to form frost with a part of cold air with much moisture which flowed out from the vegetable compartment 5 is also simple. Can be done.

  When the heater defrosting operation is started, the blower 12 and the compressor 22 are stopped, and the defrost heater 16 is driven. Thereby, the 2nd cooling part 36 and the 1st cooling part 31 which were distribute | arranged above the defrost heater 16 by the radiant heat of the defrost heater 16 are defrosted.

  According to this embodiment, the evaporator 30 has the 1st cooling part 31 formed with the micro tube, and the 2nd cooling part 36 which fixed the fin 37 to the refrigerant | coolant pipe | tube 21, The vegetable compartment 5 (1st storage room) The cool air flowing out from the cool air passage 7 in which the first cooling unit 31 is arranged is guided to the rear part of the cold air passage 7 and the cold air flowing out from the freezer compartment 4 (second storage chamber) is in front of the cold air passage 7 in which the second cooling unit 36 is arranged. Led to.

  As a result, cold air with a high amount of water exchanges heat with the first cooling unit 31 where fins are not provided, and the cold air with a low amount of water exchanges heat with the second cooler 36, and clogging of the evaporator 30 due to frost formation is suppressed. The Therefore, the power consumption of the refrigerator 1 can be reduced by lengthening the defrosting interval of the evaporator 30. Moreover, by forming the 2nd cooling part 36 in a fin tube type, production cost can be held down rather than the case where it forms with a micro tube.

  In addition, a plurality of flat tubes 34 are connected in parallel between the inflow pipe 32 and the outflow pipe 33 in which the first cooling section 31 extends vertically, and the flat tubes 34 are arranged in parallel in the vertical direction. It arrange | positions in contact with the 2nd cooling part 31. FIG. Thereby, the inside of the cold air passage 7 is partitioned forward and backward by the flat tube 34, and the cold air flowing out from the vegetable compartment 5 and the cold air flowing out from the freezer compartment 4 are separated, and the first and second cooling parts 31, 36 and the heat are respectively separated. Exchange. Therefore, the frost formation of the second cooling unit 36 can be further reduced.

  Further, since the flat tube 34 meanders in a horizontal plane and an air flow path composed of the space 7d is formed between the back wall of the cold air passage 7 and the first cooling part 31, the heat exchange area of the first cooling part 31 is further increased. Can be bigger.

  In addition, an outlet 7 b for the cold air flowing out from the freezer compartment 4 is disposed facing the second cooling unit 36. Accordingly, it is possible to easily guide the cool air with little moisture returning to the cool air passage 7 through the outlet 7b to the second cooling unit 36 and smoothly circulate the inside of the second cooling unit 36 upward from the front surface.

  In addition, the defrost heater 16 and the heater cover 17 are arranged below the second cooling unit 36, and the cold air flowing out from the vegetable compartment 5 is guided below the first cooling unit 31 through the bottom of the defrost heater 16. Thereby, cold air with a lot of moisture can be easily guided to the first cooling unit 31.

  In addition, the refrigerant discharged from the compressor 22 during the hot gas defrosting operation is the switching passage 28 (first switching passage), the first cooling unit 31, the expander 24 (first expander), and the switching passage 29 (second switching). The first cooling unit 31 is defrosted through the passage) and the second cooling unit 36 in this order. Thereby, the 2nd cooling part 36 can be maintained at low temperature, and the 1st cooling part 31 with much frost formation can be defrosted. Therefore, the temperature increase in the freezer compartment 4 can be suppressed, and the power consumption of the refrigerator 1 can be further reduced.

Second Embodiment
Next, FIG. 8 is a circuit diagram showing the refrigeration cycle 20 of the refrigerator 1 of the second embodiment. For convenience of explanation, the same reference numerals are assigned to the same parts as those in the first embodiment shown in FIGS. In the present embodiment, an expander 25 is disposed between the condenser 23 and the expander 24. Other parts are the same as those in the first embodiment.

  The expander 24 (first expander) and the expander 25 (second expander) are connected in series by a capillary tube. The switching valve 27b is provided between the expander 24 and the expander 25, and the switching passage 29 is led out from the switching valve 27b. Further, the switching valve 27b can be switched between a state in which the refrigerant flows only in the direction of the condenser 23 and a state in which the refrigerant branches through the condenser 23 and the switching passage 28. Thereby, a refrigerant | coolant can be distribute | circulated in parallel with the path | route which distribute | circulates the switching channel | path 28, the 1st cooling part 31, and the expander 24, and the path | route which distribute | circulates the condenser 23 and the expander 25. FIG.

  When each storage chamber is cooled, the refrigerant flows in the direction indicated by the arrow S1 (shown in white in the figure) by switching the switching valves 7a, 7b, and 7c. The high-temperature and high-pressure refrigerant compressed by the compressor 22 is condensed while dissipating heat in the condenser 23. The high-temperature refrigerant expands in the expander 25 and the expander 24 to become low-temperature and low-pressure, and is sent to the evaporator 30. The refrigerant flowing into the evaporator 30 exchanges heat with the cold air flowing through the cold air passage 7, evaporates while absorbing heat, and is sent to the compressor 22 as a low-temperature gas refrigerant.

  The blower 12 is stopped during the hot gas defrosting operation, and the refrigerant flows in the direction indicated by the arrow S2 (shown in black in the drawing) by switching the switching valves 7a, 7b, and 7c. The high-temperature and high-pressure refrigerant compressed by the compressor 22 branches at the switching valve 27b and condenses while releasing heat at the condenser 23 and the first cooling unit 31. Thereby, the 1st cooling part 31 is defrosted.

  The high-temperature refrigerant that has flowed out of the condenser 23 flows into the expander 25, and the high-temperature refrigerant that has flowed out of the first cooling unit 31 flows into the expander 24. The refrigerant expands in the expanders 24 and 25 to become low temperature and low pressure, merges in the switching passage 29, and is sent to the second cooling unit 36. The refrigerant flowing into the second cooling unit 36 exchanges heat with the cold air in the cold air passage 7, evaporates while absorbing heat, and is sent to the compressor 22 as a low-temperature gas refrigerant.

  According to this embodiment, the same effect as that of the first embodiment can be obtained. Further, an expander 24 (first expander) and an expander 25 (second expander) are provided, and the refrigerant that branches in the switching valve 27a and flows in parallel at the time of hot gas defrosting is the condenser 23 and the first cooler. 31 is condensed. For this reason, the heat dissipation amount of the refrigerant is increased by the condenser 23 and the first cooler 31, and the second cooling unit 36 can be maintained at a lower temperature. Therefore, the temperature increase of the freezer 4 can be further suppressed, and the refrigerator 1 can save more power.

  In the first and second embodiments, a hot gas defrosting operation that mainly defrosts the first cooling unit 31 is performed, and the refrigerator 1 that performs only the heater defrosting operation without providing the hot gas defrosting operation is provided. Also good. In this case as well, the power consumption of the refrigerator 1 can be reduced by increasing the defrosting interval of the evaporator 30 as described above.

  According to this invention, it can utilize for the refrigerator provided with the evaporator.

DESCRIPTION OF SYMBOLS 1 Refrigerator 2 Heat insulation box 3 Refrigerating room 3a, 4a, 5a Door 4 Freezer room 5 Vegetable room 6 Machine room 7, 8 Cold air passage 7a, 8a Outlet 7b, 7c Outlet 7d Space 12 Blower 15 Damper 16 Defrost heater 17 Heater cover 20 Refrigeration cycle 21 Refrigerant pipe 22 Compressor 23 Condenser 24, 25 Expander 26 Check valve 27a, 27b, 27c Switching valve 28, 29 Switching passage 30 Evaporator 31 First cooling section 32 Inflow pipe 33 Outflow pipe 34 Flat tube 35 Narrow passage 36 Second cooling part 37 Fin

Claims (7)

  A first storage room for storing stored items in a refrigerator, a second storage room for storing stored items in a frozen state, a cool air passage through which a blower is provided to distribute cool air in the vertical direction, and a cool air passage for generating cold air. A first cooling unit formed by a microtube partitioned by a plurality of narrow passages through which the refrigerant flows in a flat tube, with the evaporator disposed at the rear of the cold air passage. A second cooling part disposed adjacent to the first cooling part in the front part of the cold air passage and formed by fixing a number of fins to the refrigerant pipe, and the cold air flowing out of the first storage chamber The refrigerator, wherein the refrigerator is led to a rear portion of the cold air passage, and cool air flowing out from the second storage chamber is led to a front portion of the cold air passage.   A plurality of the flat tubes are connected in parallel between an inflow pipe and an outflow pipe through which the first cooling portion extends vertically and the refrigerant flows, and the flat passages are arranged in parallel in the vertical direction. The refrigerator according to claim 1, wherein the refrigerator is disposed in contact with the second cooling unit.   The refrigerator according to claim 2, wherein the flat tube meanders in a horizontal plane, and an air flow path is formed between a back wall of the cold air passage and the first cooling part.   The refrigerator according to any one of claims 1 to 3, wherein an outlet for cold air flowing out of the second storage chamber is arranged facing the second cooling unit.   A defrosting heater disposed below the second cooling unit to defrost the evaporator; and a heater cover covering the top of the defrosting heater, and the cool air flowing out of the first storage chamber is The refrigerator according to any one of claims 1 to 4, wherein the refrigerator is guided below the first cooling unit through the lower part.   A compressor for operating a refrigeration cycle; a condenser connected to the compressor; a first expander disposed between the condenser and the evaporator; and between the compressor and the condenser A first switching passage branched from the first cooling section and connected between the first cooling section and the second cooling section, and a first switching section and a second cooling section branched from between the condenser and the expander And a second switching passage connected between the refrigerant, the refrigerant discharged from the compressor flows in the order of the condenser, the first expander, and the evaporator, and cold air is exchanged by heat exchange with the evaporator. And the refrigerant discharged from the compressor flows in the order of the first switching passage, the first cooling section, the first expander, the second switching passage, and the second cooling section, and the first cooling section is the refrigerant. 6. The hot gas defrosting operation for defrosting by condensation is performed at a predetermined time. The refrigerator according to or Re.   A second expander is provided between the first expander and the condenser, and a second switching passage branches from between the first expander and the second expander, and the first switching is performed during the hot gas defrosting operation. 7. The refrigerant merges after the refrigerant flows in parallel through the passage, the path through the first cooling unit and the first expander, and the path through the condenser and the second expander. Refrigerator.

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