Refrigerator

Abstract

The invention provides a refrigerator capable of defrosting in a short time and with higher heating efficiency. A refrigerator (1) is provided with: a compressor (24) that compresses a refrigerant; a heat dissipation mechanism (50) that dissipates heat from the refrigerant; a refrigeration evaporator (R evaporator 14a) that evaporates the refrigerant during the refrigeration cooling operation; a freezing evaporator (F evaporator 14b) that evaporates the refrigerant during the freezing-cooling operation; and a defrosting pipe (102) which is disposed inside or near the freezing evaporator and exchanges heat with the freezing evaporator during the defrosting operation. The flow path resistance (R1) of a refrigerant path (FP8) connecting the outlet (Out102) of the defrosting pipe (102) to the inlet (In14a) of the refrigeration evaporator is set to be lower than the flow path resistance (R2) of refrigerant paths (FP3, FP4a) connecting the outlet (Out50) of the heat dissipation mechanism (50) to the inlet (In14a) of the refrigeration evaporator.

Description

Technical Field

[0001] The invention relates to a refrigerator. Background Art

[0002] In the past, as technologies related to refrigerators, there are technologies described in Patent Documents 1 and 2, for example. Patent Documents 1 and 2 describe refrigerators that use heat dissipation of a refrigeration cycle to heat the refrigerant using a freezing cooler (first cooler) while causing the refrigerant to flow to a refrigerating cooler (second cooler), thereby performing a defrosting operation to remove frost attached to the freezing cooler. A freezing cooler is a cooler used in an operation to cool a freezing chamber (freezing cooling operation). A refrigerating cooler is a cooler used in an operation to cool a refrigerating chamber (refrigerating cooling operation). These conventional refrigerators can cool the refrigerating chamber during a defrosting operation, and can use the heat obtained by the refrigerant during the defrosting operation to heat the freezing cooler, so that defrosting can be performed more efficiently than defrosting using an electric heater.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Patent Publication No. 6687384

[0006] Patent Document 2: Japanese Patent Application Publication No. 2019-215147 Summary of the invention

[0007] Problems to be solved by the invention

[0008] However, the refrigerator described in Patent Document 1 and the refrigerator described in Patent Document 2 tend to take a long time to defrost for the following reasons, and it is desired to perform defrosting with higher heating efficiency.

[0009] For example, the refrigerator described in Patent Document 1 allows the refrigerant to flow from the downstream side of the first heat dissipation mechanism to the defrost pipe. Therefore, the heat of the refrigerant flowing into the defrost pipe decreases. In addition, the defrost pipe is described as a refrigerant flow path branched from the high-temperature side refrigerant flow path where the high-temperature liquid refrigerant circulates. As a result, the refrigerant flowing into the defrost pipe releases at least the amount of heat before the gas refrigerant just after being ejected from the compressor becomes a gas-liquid state. Therefore, the refrigerant flowing into the defrost pipe is liquefied at the moment of inflow, so the amount of heat that can be dissipated is less. Therefore, the refrigerator described in Patent Document 1 can use a smaller amount of heat for heating the freezing cooler (first cooler) through the defrost pipe, and the defrosting time tends to be longer.

[0010] In addition, since at least a portion of the refrigerant flowing into the defrost pipe is liquefied, heat exchange is performed by the first heat dissipation mechanism until it flows into the defrost pipe, so that the condensation temperature becomes higher than the external temperature. That is, the refrigerator described in Patent Document 1 condenses the refrigerant at the location where heat exchange is performed with the external air, and therefore dissipates heat to the external air at this location. At this time, since the refrigerant dissipates heat, the temperature of the refrigerant is higher than the temperature of the external air. In other words, the refrigerant reaches the condensation temperature by dissipating heat, so the condensation temperature of the refrigerant becomes higher than the temperature of the external air. For defrosting, it is sufficient as long as the temperature of the refrigerant exceeds the freezing point, but since the condensation temperature is higher than the external temperature, that is, since the pressure of the refrigerant is increased to a higher condensation pressure, the workload of the compressor increases. As a result, the heating efficiency of the refrigerator (the amount of heating of the freezer cooler (first cooler) relative to the amount of power consumed) becomes lower. Therefore, it is desired that the refrigerator defrosts in a short time and with higher heating efficiency.

[0011] On the other hand, in the refrigerator described in Patent Document 2, the refrigerant just ejected from the compressor flows to the defrost pipe, but the return portion of the defrost pipe is before the cooling switching valve. In addition, in the refrigerator described in Patent Document 2, a decompression device used for cooling is connected to the downstream side of the cooling switching valve. In such a refrigerator described in Patent Document 2, when the refrigerant flows to the defrost pipe, the heat dissipation mechanism is only the defrost pipe, and the expansion mechanism becomes a decompression device used for refrigeration cooling. In the case where the heat dissipation mechanism is only the defrost pipe, the condensation temperature becomes a temperature close to the heat exchange object of the defrost pipe (the frost-covered refrigeration cooler (first cooler)). Therefore, there is a possibility that the condensation temperature is close to the freezing point temperature, that is, the condensation pressure is lower than that during refrigeration cooling. If the decompression device for refrigeration cooling is used to reduce the pressure from the lower condensation pressure, the evaporation pressure drops excessively. Therefore, the pressure of the gas refrigerant sucked by the compressor drops. If the pressure of the gas refrigerant is low, the density of the refrigerant becomes low, the ratio of the refrigerant circulation volume to the displacement and the rotation speed of the compressor becomes small, and the heat used for heating the refrigeration cooler (first cooler) becomes small. In addition, since the pressure of the gas refrigerant sucked by the compressor is low, the workload of the compressor for increasing the pressure to the condensing pressure (more precisely, the workload per refrigerant circulation) increases, and the heating efficiency decreases. Therefore, it is hoped that the refrigerator can be defrosted in a shorter time and with higher heating efficiency.

[0012] The present invention is a solution proposed to solve the above-mentioned problems, and a main object of the present invention is to provide a refrigerator capable of defrosting in a short time and with higher heating efficiency.

[0013] Solutions to Solve Problems

[0014] In order to achieve the above-mentioned purpose, the present invention provides a refrigerator, comprising: a refrigerating chamber; a freezing chamber; a compressor, which compresses a refrigerant; a heat dissipation mechanism, which releases heat from the refrigerant; a refrigerating evaporator, which evaporates the refrigerant during a refrigerating and cooling operation for cooling the refrigerating chamber; a freezing evaporator, which evaporates the refrigerant during a freezing and cooling operation for cooling the freezing chamber; and a defrosting pipe, which is arranged inside or near the freezing evaporator and exchanges heat with the freezing evaporator, and is constructed so that, during a defrosting operation, the refrigerant ejected from the compressor flows in the order of the defrosting pipe, the refrigerating evaporator, and the compressor, thereby heating the freezing evaporator to remove frost attached to the freezing evaporator, and adopts the following structure, wherein the flow resistance of the refrigerant path connecting the outlet of the defrosting pipe to the inlet of the refrigerating evaporator is set to be lower than the flow resistance of the refrigerant path connecting the outlet of the heat dissipation mechanism to the inlet of the refrigerating evaporator.

[0015] Other options will be described later.

[0016] Effects of the Invention

[0017] According to the present invention, it is possible to provide a refrigerator capable of performing defrosting in a short time and with higher heating efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a front view showing the structure of the refrigerator according to the first embodiment.

[0019] Figure 2 yes Figure 1 A cross-sectional view taken along line X1-X1 is shown.

[0020] Figure 3 yes Figure 2 A cross-sectional view taken along line X2-X2 is shown.

[0021] Figure 4A It is a perspective view showing the structure of the F evaporator in the refrigerator of the first embodiment.

[0022] Figure 4B It is an enlarged side view showing the structure of the fins of the F evaporator in the refrigerator of the first embodiment.

[0023] Figure 5 It is a schematic diagram showing the structure of a refrigeration cycle (refrigerant flow path) in the refrigerator of the first embodiment.

[0024] Fig. 6A It is an explanatory diagram showing the flow of the refrigerant during the refrigeration cooling operation (R cooling operation) in the refrigerator according to the first embodiment.

[0025] Figure 6BIt is an explanatory diagram showing the flow of the refrigerant during the freezing and cooling operation (F cooling operation) in the refrigerator according to the first embodiment.

[0026] Figure 6C It is an explanatory diagram showing the flow of the refrigerant during the defrosting operation in the refrigerator according to the first embodiment.

[0027] Figure 7 This is a P-h diagram showing the refrigeration cycle state during defrosting operation.

[0028] Figure 8 It is a schematic diagram showing a refrigeration cycle (refrigerant flow path) of a first comparative example.

[0029] Fig. 9 It is a schematic diagram showing a refrigeration cycle (refrigerant flow path) of a second comparative example.

[0030] Fig.10 It is a Ph diagram showing the states in the defrosting operation of the refrigeration cycle of the first embodiment, the refrigeration cycle of the first comparative example, and the refrigeration cycle of the second comparative example.

[0031] Fig.11 It is a schematic diagram showing the structure of a refrigeration cycle (refrigerant flow path) in a refrigerator according to a second embodiment.

[0032] In the figure:

[0033] 1, 1A, 1001, 1002—refrigerator, 2—refrigerating chamber, 7—freezing chamber, 8a—R evaporator chamber (evaporator chamber for refrigerating), 8b—F evaporator chamber (evaporator chamber for freezing), 14a—R evaporator (evaporator for refrigerating, cooler for refrigerating), 14b—F evaporator (evaporator for freezing, cooler for freezing), 24—compressor, 31—control substrate (control device, control unit), 50—heat dissipation mechanism, 50a—external radiator, 50b—wall heat dissipation piping, 50c—condensation prevention piping, 51—dryer, 52—three-way valve (first refrigerant control mechanism), 52a, 52b, 101a, 101b—outlet, 53—capillary tube (decompression mechanism), 53a—R capillary tube (decompression mechanism for refrigerating), 53b—F capillary tube (decompression mechanism for freezing) , 54a—R gas-liquid separator, 54b—F gas-liquid separator, 55, 104, 204—check valve, 56, 113—refrigerant confluence, 57—suction pipe, 58—internal heat exchange part (heat exchange part), 59—F evaporator refrigerant piping, 101—three-way valve (second refrigerant control mechanism), 102—defrost pipe (refrigerant pipe), 103—defrost capillary (defrost pressure reducing mechanism), 105, 106, 110, 113—confluence part, 111—branch part, 112—two-way valve (refrigerant flow path closing mechanism, third refrigerant flow path control mechanism), 120—fin, 201—three-way valve, 203—defrost capillary (defrost pressure reducing mechanism), In14a—inlet, Out50—outlet, R1, R2, R53a, R103—flow path resistance. DETAILED DESCRIPTION

[0034] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail with reference to the accompanying drawings. In addition, each figure is merely a schematic illustration to enable a full understanding of the present invention. Therefore, the present invention is not limited to the illustrated examples. In addition, in each figure, the same symbols are marked for common components and the same components, and their repeated descriptions are omitted.

[0035] [First embodiment]

[0036] <Overall structure of refrigerator 1>

[0037] Below, refer to Figures 1 to 3 , the structure of the refrigerator 1 of the first embodiment is described. Figure 1 It is a front view showing the structure of the refrigerator 1 according to the first embodiment. Figure 2 yes Figure 1 A cross-sectional view taken along line X1-X1 is shown. Figure 3 yes Figure 2 The cross-sectional view is shown along the line X2 - X2. In the following description, a six-door refrigerator 1 is taken as an example, but the refrigerator 1 is not limited to six doors.

[0038] The refrigerator 1 has the functions of performing refrigeration and cooling operation, freezing and cooling operation, and defrosting operation. The refrigeration and cooling operation is for the refrigerating chamber 2 ( Figure 1 ) is operated to cool. The refrigeration cooling operation is performed on the freezing chamber 7 ( Figure 1 ) to cool. The defrosting operation is to remove the F evaporator 14b ( Figure 2 as well as Figure 3 ) of frost (even attached to the freezing chamber 7 (described later) Figure 1 ) of frost) of operation.

[0039] In the following description, "refrigerated cooling" may be referred to as "R cooling" and "refrigerated cooling operation" may be referred to as "R cooling operation". In addition, "frozen cooling" may be referred to as "F cooling" and "frozen cooling operation" may be referred to as "F cooling operation". In addition, refrigerated cooling operation and frozen cooling operation may be collectively referred to as "cooling operation". In addition, regarding components related to "refrigerated cooling operation", "R" which means "refrigerated cooling" is added to the beginning for description. In addition, regarding components related to "frozen cooling operation", "F" which means "frozen cooling" is added to the beginning for description.

[0040] like Figure 1 As shown, the heat-insulating box body 10 of the refrigerator 1 has storage rooms in the order of a refrigerator compartment 2, an ice-making compartment 3 and an upper freezer compartment 4 arranged side by side, a lower freezer compartment 5, and a vegetable compartment 6 from the top. The refrigerator 1 is provided with doors for opening and closing the openings of the respective storage rooms. These doors are the doors 2a and 2b of the refrigerator compartment 2 which are divided into the left and right and which are rotary, and the door 3a of the ice-making compartment 3, the door 4a of the upper freezer compartment 4, the door 5a of the lower freezer compartment 5, and the door 6a of the vegetable compartment 6 which are drawer-type and which respectively open and close the openings of the ice-making compartment 3, the upper freezer compartment 4, the lower freezer compartment 5, and the vegetable compartment 6. In order to fix the doors 2a and 2b of the refrigerator compartment 2 to the refrigerator 1, door hinges (not shown) are provided at the upper and lower parts of the refrigerator compartment 2, and the upper door hinge is covered by a door hinge cover 16.

[0041] The refrigerator compartment 2 and the vegetable compartment 6 are refrigerated storage compartments that are basically controlled to a refrigerated temperature zone (above 0°C), for example, the refrigerator compartment 2 is controlled to about 4°C, and the vegetable compartment 6 is controlled to about 6°C. The ice-making compartment 3, the upper freezer compartment 4, and the lower freezer compartment 5 are frozen storage compartments that are controlled to a freezing temperature zone (less than 0°C), for example, to an average of about -20°C. In addition, the ice-making compartment 3, the upper freezer compartment 4, and the lower freezer compartment 5 that are frozen storage compartments are hereinafter referred to as the freezer compartment 7.

[0042] like Figure 2As shown, the refrigerator 1 is formed by filling a foam insulation material (such as foamed polyurethane) between an outer box 10a (steel plate) and an inner box 10b (synthetic resin) to form an insulated box 10, which is called a structure that separates the outside of the box from the inside of the box. In the insulated box 10, in addition to installing a foam insulation material such as foamed polyurethane foam, a vacuum insulation material 25 with a lower thermal conductivity than the foam insulation material is installed between the outer box 10a and the inner box 10b, thereby improving the insulation performance without reducing the food storage volume. Here, the vacuum insulation material 25 is formed by using an outer packaging material to cover a core material such as glass wool and polyurethane. The outer packaging material includes a metal layer (such as aluminum) to ensure gas barrier properties. In addition, the above-mentioned vacuum insulation material 25 is arranged on the top wall, left and right walls, back wall, and bottom wall of the insulated box 10. In addition, in order to improve the insulation performance, the door 5a of the lower freezer 5, which is a relatively large frozen storage room, is also embedded with a vacuum insulation material 25.

[0043] The cold storage room 2, the ice making room 3 and the upper freezer room 4 are separated by an insulating partition wall 28. The lower freezer room 5 and the vegetable room 6 are separated by an insulating partition wall 29. In addition, an insulating partition wall 30 is provided on the front side between the ice making room 3, the upper freezer room 4 and the lower freezer room 5 to prevent the air in the refrigerator 1 from leaking out of the box through the gaps between the doors 3a, 4a and 5a, and to prevent the air outside the box from invading the storage rooms. In addition, in the first embodiment, an electric heater (not shown) for heating the vegetable room 6 is provided at the lower part of the insulating partition wall 29 to prevent the vegetable room 6 from becoming excessively low in temperature.

[0044] The doors 2a, 2b of the refrigerator room 2 are provided with a plurality of door pockets 33a, 33b, 33c on the inner side of the box. In addition, the refrigerator room 2 is divided into a plurality of storage spaces by shelves 34a, 34b, 34c, 34d. In addition, a low-temperature storage space 36 is provided at the lower part of the refrigerator room 2 (the upper part of the insulating partition wall 28). The interior of the storage room 35 in the box is maintained at about -1 to +1°C, and the refrigerator room 2 is particularly maintained at a low temperature. In addition, the generally closed space where cold air is not directly delivered to the storage room 35 in the box becomes a space for storing food (such as meat, fish, etc.) that is required to be prevented from drying out, especially at low temperatures.

[0045] The ice making room 3, upper freezer room 4, lower freezer room 5 and vegetable room 6 are respectively provided with an ice making room container, an upper freezer room container 4b, a lower freezer room container 5b and a vegetable room container 6b which are pulled out integrally with the doors 3a, 4a, 5a and 6a.

[0046] The R evaporator 14a, which is a refrigeration evaporator (cooler), is housed in the R evaporator chamber 8a, which is a refrigeration evaporator chamber. The R evaporator chamber 8a is formed by an R air duct component 61 provided at approximately the back of the refrigeration chamber 2 and an inner box 10b. The air in the R evaporator chamber 8a, which has undergone heat exchange with the R evaporator 14a and has become low temperature, passes through the R fan 9a, which is a refrigeration fan provided above the R evaporator 14a, and is sent to the refrigeration chamber 2 from the refrigeration chamber outlet 11a provided in the R air duct component 61 via the refrigeration chamber air duct 11, thereby cooling the inside of the refrigeration chamber 2. The air sent to the refrigeration chamber 2 is sent from the refrigeration chamber return ports 15a, 15b ( Figure 3 ) returns to the R evaporator chamber 8a and is cooled again by the R evaporator 14a.

[0047] The refrigerating chamber discharge port 11a is mainly provided at the upper part of the refrigerating chamber 2. In addition, the refrigerating chamber return ports 15a and 15b are provided at the lower part of the refrigerating chamber 2, the refrigerating chamber return port 15a is provided at the substantially back side of the in-box storage chamber 35 at the lowest level of the refrigerating chamber 2 (between the shelf 34d and the heat-insulating partition wall 28), and the refrigerating chamber return port 15b is provided at the second level from the bottom of the refrigerating chamber 2 (between the shelf 34c and the shelf 34d).

[0048] The F evaporator 14b, which is a freezing evaporator (cooler), is housed in the F evaporator chamber 8b, which is a freezing evaporator chamber. The F evaporator chamber 8b is composed of an F air duct component 62 provided substantially at the back of the freezing chamber 7 and an inner box 10b. The air in the F evaporator chamber 8b, which has been subjected to heat exchange with the F evaporator 14b and has become low temperature, is blown to the freezing chamber 7 from the freezing chamber outlet 12a provided in the F air duct component 62 by the F fan 9b, which is a freezing fan provided above the F evaporator 14b, through the freezing chamber air duct 12, thereby cooling the freezing chamber 7. The air transported to the freezing chamber 7 returns to the F evaporator chamber 8b from the freezing chamber return port 17 provided in the F air duct component 62, and is cooled again by the F evaporator 14b.

[0049] In the refrigerator 1 of the first embodiment, the vegetable compartment 6 is also cooled by low-temperature air through the F evaporator 14b. The air in the F evaporator chamber 8b that has become low-temperature through the F evaporator 14b is transported to the vegetable compartment 6 by the F fan 9b via the vegetable compartment air path (not shown) and the vegetable compartment damper (not shown), thereby cooling the inside of the vegetable compartment 6. In addition, although the low-temperature air generated by the F evaporator 14b is transported to the vegetable compartment 6, the low-temperature air is not allowed to directly enter the vegetable compartment container 6b for storing food, thereby suppressing the drying of the vegetables. When the vegetable compartment 6 is at a low temperature, the cooling of the vegetable compartment 6 is suppressed by closing the vegetable compartment damper. The air transported to the vegetable compartment 6 returns to the lower part of the F evaporator 14b through the vegetable compartment cold air return air path 18 from the cold air return port 18a provided on the vegetable compartment side in front of the lower part of the heat-insulating partition wall 29.

[0050] When air containing moisture flows into the refrigerator by opening and closing the door, the moisture in the air becomes frost and adheres to the surfaces of the low-temperature R evaporator 14a and F evaporator 14b. If the frost grows, it hinders the heat exchange between the evaporator and the air, and the air volume flowing through the evaporator decreases due to the ventilation resistance of the frost. Therefore, the refrigerator performs a defrosting operation to melt the frost on the evaporator.

[0051] F evaporator 14b passes Figure 4A The defrosted water (melted water) generated by the F evaporator 14b during defrosting falls to the F gutter 23b provided at the bottom of the F evaporator chamber 8b, and is discharged to the evaporation pan 32 provided at the top of the compressor 24 through the F drain port 22b and the F drain pipe 27b.

[0052] The R evaporator 14a circulates the air of the refrigerating chamber 2 and performs defrosting by stop-cycle defrosting using the heat of the refrigerating chamber 2. Defrosted water generated by the R evaporator 14a during defrosting falls toward the R flow channel 23a provided at the lower portion of the R evaporator chamber 8a, and is discharged to the evaporation pan 32 provided in the machine chamber 39 through the R drain port (not shown) and the R drain pipe (not shown).

[0053] The water discharged to the evaporation pan 32 is heated by heat dissipation of the compressor 24 and the external radiator 50a, etc., and is vaporized by air blown by the machine room fan 38, etc., and is discharged to the outside of the refrigerator.

[0054] A refrigerator compartment temperature sensor 41, a freezer compartment temperature sensor 42, and a vegetable compartment temperature sensor 43 are provided on the back side of the refrigerator compartment 2, the freezer compartment 7, and the vegetable compartment 6, respectively. An R evaporator temperature sensor 40a is provided on the upper part of the R evaporator 14a, and an F evaporator temperature sensor 40b is provided on the upper part of the F evaporator 14b. These sensors are used to detect the temperatures of the refrigerator compartment 2, the freezer compartment 7, the vegetable compartment 6, the R evaporator 14a, and the F evaporator 14b. In addition, an external air temperature sensor 37a for detecting the temperature of the external air (air outside the box) and an external air humidity sensor 37b for detecting the humidity are provided inside the door hinge cover 16 on the top surface of the refrigerator 1. As other sensors, door sensors (not shown) for detecting the open and closed states of the doors 2a, 2b, 3a, 4a, 5a, and 6a are also provided.

[0055] A control substrate 31 (control device, control unit) equipped with a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory) and other memories, an interface circuit and the like as a part of the control device is arranged in the machine room 39 of the refrigerator 1. The control substrate 31 is connected to an outside air temperature sensor 37a, an outside air humidity sensor 37b, a refrigerating chamber temperature sensor 41, a freezing chamber temperature sensor 42, a vegetable chamber temperature sensor 43, an R evaporator temperature sensor 40a, an F evaporator temperature sensor 40b, a door sensor and the like through electrical wiring (not shown).

[0056] In addition, the control board 31 controls the compressor 24, the R fan 9a, the F fan 9b, the machine room fan 38, and the vegetable room damper based on the output values ​​of the sensors, the settings of the operation unit 26, the program recorded in advance in the ROM, etc. In addition, the operation unit 26 is provided in the inner box 10b ( Figure 2 ) can provide instructions for adjusting the temperatures of the refrigerator compartment 2, freezer compartment 7, and vegetable compartment 6, and for implementing additional functions such as a quick freezing function for improving the cooling capacity of the freezer compartment 7.

[0057] <Structure of F evaporator 14b>

[0058] Below, refer to Figure 4A as well as Figure 4B , the structure of the F evaporator 14b is described. Figure 4A It is a perspective view showing the structure of the F evaporator 14b. Figure 4B It is an enlarged side view showing the structure of the fin 120 of the F evaporator 14b.

[0059] like Figure 4AAs shown in FIG. 1 , the F evaporator 14b includes an F evaporator refrigerant pipe 59 and fins 120. The F evaporator refrigerant pipe 59 is a pipe described later. Figure 5 The F evaporator 14b is a refrigerant pipe extending from the refrigerant inflow portion of the F evaporator chamber 8b to the F gas-liquid separator 54b downstream of the F capillary tube 53b shown in FIG. 1 . The F evaporator 14b cools the air in the cabinet by exchanging heat between the air and the low-temperature refrigerant in the F evaporator refrigerant pipe 59 during cooling operation. The fin 120 is a heat dissipation component for improving the heat exchange efficiency from the F evaporator refrigerant pipe 59 to the air. The fin 120 is provided to perform heat exchange with a refrigerant pipe different from the F evaporator refrigerant pipe 59, namely, a defrost pipe 102, in addition to the F evaporator refrigerant pipe 59. In the cycle defrosting described later, the frost attached to the fin 120, namely, the F evaporator 14b, is heated by flowing a high-temperature refrigerant into the defrost pipe 102, and the frost is melted to perform defrosting. Furthermore, in order to improve the heat transfer performance to the fins 120 , the F evaporator refrigerant pipe 59 and the defrost pipe 102 are expanded to improve the contact with the fins 120 .

[0060] <Structure and operation of refrigeration cycle (refrigerant flow path) in refrigerator 1>

[0061] Below, refer to Figure 5 , Figure 6A to Figure 6C , the structure and operation of the refrigeration cycle (refrigerant flow path) in the refrigerator 1 are explained. Figure 5 It is a schematic diagram showing the structure of a refrigeration cycle (refrigerant flow path) in the refrigerator 1 according to the first embodiment. Fig. 6A It is an explanatory diagram showing the flow of the refrigerant during the refrigeration cooling operation (R cooling operation) in the refrigerator 1. Figure 6B It is an explanatory diagram showing the flow of the refrigerant during the freezing and cooling operation (F cooling operation) in the refrigerator 1. Figure 6C It is an explanatory diagram showing the flow of the refrigerant during the defrosting operation in the refrigerator 1.

[0062] like Figure 5 As shown, the refrigerator 1 includes a compressor 24, a heat dissipation mechanism 50, a dryer 51, a three-way valve 52, a capillary tube 53, an R evaporator 14a, an F evaporator 14b, an R gas-liquid separator 54a, an F gas-liquid separator 54b, and a check valve 55. In addition, the refrigerator 1 includes a three-way valve 101, a defrosting pipe 102, a defrosting capillary tube 103, and a check valve 104.

[0063] The compressor 24 is a component that compresses the refrigerant.

[0064] The heat dissipation mechanism 50 is a component that releases heat from the refrigerant. Here, the heat dissipation mechanism 50 is described as having an external radiator 50a and a wall heat dissipation pipe 50b for dissipating heat from the refrigerant, and a condensation prevention pipe 50c for suppressing condensation on the front part of the insulating partition walls 28, 29, and 30.

[0065] The dryer 51 is a component that removes moisture in the refrigeration cycle.

[0066] The three-way valve 52 is a refrigerant control mechanism that controls whether the refrigerant flows to the R evaporator 14a side or the F evaporator 14b side. Hereinafter, the "three-way valve 52" may be referred to as the "first refrigerant control mechanism". The three-way valve 52 includes an outflow port 52a connected to the R capillary tube 53a via a refrigerant pipe, and an outflow port 52b connected to the F capillary tube 53b via a refrigerant pipe, and can switch the outflow port through which the refrigerant flows.

[0067] The capillary tube 53 is a decompression mechanism for decompressing the refrigerant. The capillary tube 53 includes an R capillary tube 53a (refrigeration capillary tube) for decompressing the refrigerant flowing toward the R evaporator 14a side, and an F capillary tube 53b (freezing capillary tube) for decompressing the refrigerant flowing toward the F evaporator 14b side.

[0068] The R evaporator 14 a is an evaporator for refrigeration (cooler) that absorbs the heat in the refrigerating room 2 by exchanging heat between the air in the refrigerating room 2 and the refrigerant.

[0069] The F evaporator 14 b is a freezing evaporator (cooler) that absorbs heat in the freezing chamber 7 by exchanging heat between the air in the freezing chamber 7 and the refrigerant.

[0070] The R gas-liquid separator 54a and the F gas-liquid separator 54b are components for separating the gas refrigerant from the liquid refrigerant and preventing the liquid refrigerant from flowing into the compressor 24. The R gas-liquid separator 54a is provided on the downstream side of the R evaporator 14a. The F gas-liquid separator 54b is provided on the downstream side of the F evaporator 14b.

[0071] The check valve 55 is a component for suppressing the backflow of the refrigerant. The check valve 55 is provided between the F gas-liquid separator 54b and the refrigerant junction 56. The refrigerant junction 56 is a location where the refrigerant flow path FP4 and the refrigerant flow path FP5 described later merge (connect) with each other.

[0072] The three-way valve 101 is a refrigerant control mechanism that switches the direction of the refrigerant flow when performing cooling operation (refrigerated cooling operation and frozen cooling operation) and when performing defrosting operation. The three-way valve 101 allows the refrigerant to flow to the heat dissipation mechanism 50 side when performing cooling operation (refrigerated cooling operation and frozen cooling operation), and on the other hand, allows the refrigerant to flow to the defrosting pipe 102 side when performing defrosting operation. Hereinafter, there is a case where the "three-way valve 101" is referred to as the "second refrigerant control mechanism". The three-way valve 101 has an outlet 101a connected to the external radiator 50a via a refrigerant piping, and an outlet 101b connected to the defrosting pipe 102, and can switch the outlet through which the refrigerant flows.

[0073] The defrosting pipe 102 is a pipe through which a high-temperature refrigerant for heating the F evaporator 14 b flows during the defrosting operation of the F evaporator 14 b.

[0074] The defrosting capillary tube 103 is a decompression mechanism that decompresses the refrigerant flowing in the defrosting pipe 102 .

[0075] The check valve 104 is a component that suppresses the refrigerant from flowing into the defrosting pipe 102 during cooling operation. The check valve 104 is provided between the defrosting pipe 102 and the confluence portion 105. The confluence portion 105 is a portion where the refrigerant piping (refrigerant flow path FP4) of the refrigeration and cooling operation and the refrigerant piping (refrigerant flow path FP8) of the defrosting operation merge (connect).

[0076] The refrigerator 1 has a refrigerant flow path FP so that the refrigerant flows between these components. Figure 6A to Figure 6C In the example shown, the refrigerant flow path FP has a structure including refrigerant flow paths FP1 to FP8. Figure 6A to Figure 6C The example shown is merely an example, and the refrigerant flow path FP may be formed by partially subdividing (dividing) the refrigerant flow paths FP1 to FP8 into a plurality of pipes, or by partially connecting the refrigerant flow paths FP1 to FP8.

[0077] The refrigerant flow path FP1 is configured to connect the compressor 24 to the three-way valve 101 .

[0078] The refrigerant flow path FP2 is configured to connect the three-way valve 101 to the condensation prevention pipe 50 c of the heat dissipation mechanism 50 through the external radiator 50 a and the wall surface heat dissipation pipe 50 b of the heat dissipation mechanism 50 .

[0079] The refrigerant flow path FP3 is configured to connect the condensation prevention pipe 50 c of the heat dissipation mechanism 50 to the three-way valve 52 via the dryer 51 .

[0080] The refrigerant flow path FP4 is configured to pass through the R capillary tube 53a, the R evaporator 14a, and the R gas-liquid separator 54a, and connect the three-way valve 52 to the refrigerant confluence portion 56. In addition, in the following description, the portion of the refrigerant flow path FP4 connecting the three-way valve 52 to the inlet In14a of the R evaporator 14a is referred to as "refrigerant flow path FP4a". In addition, the portion connecting the confluence portion 105 to the refrigerant confluence portion 56 is referred to as "refrigerant flow path FP4b".

[0081] The refrigerant flow path FP5 is configured to connect the three-way valve 52 to the refrigerant junction 56 via the F capillary tube 53 b , the F evaporator 14 b , the F gas-liquid separator 54 b , and the check valve 55 .

[0082] The refrigerant flow path FP6 is configured to connect the refrigerant junction 56 to the compressor 24. The refrigerator 1 has an internal heat exchanger 58. The internal heat exchanger 58 is a heat exchanger in which the R capillary tube 53a, the F capillary tube 53b and the defrosting capillary tube 103 can exchange heat with the refrigerant flow path FP6 (suction pipe 57 described later).

[0083] The refrigerant flow path FP7 is configured to connect the three-way valve 101 to the defrosting pipe 102 .

[0084] The refrigerant flow path FP8 is configured to connect the defrost pipe 102 to the junction 105 via the defrost capillary tube 103 and the check valve 104. The order of the defrost capillary tube 103 and the check valve 104 may be reversed.

[0085] The three-way valve 52 has two outflow ports 52a and 52b, and is a component that can switch the direction of the refrigerant flow. In addition, the three-way valve 52 can be in a fully closed state in a manner that the refrigerant does not flow to both the outflow port 52a and the outflow port 52b. In addition, the three-way valve 52 can also be in a two-open state in a manner that the refrigerant flows to both the outflow port 52a and the outflow port 52b. The outflow port 52a of the three-way valve 52 is connected to the R capillary 53a via the refrigerant piping. On the other hand, the outflow port 52b of the three-way valve 52 is connected to the F capillary 53b via the refrigerant piping.

[0086] In the present embodiment, the refrigerant return pipe (refrigerant flow path FP6) for returning the refrigerant from the R evaporator 14a and the F evaporator 14b to the compressor 24 in the refrigerant pipe FP is referred to as a "suction pipe 57". Figure 4A As shown, the capillary 53b ( Figure 5 )'s outlet passes through the F evaporator 14b and is connected to the F gas-liquid separator 54b through the F evaporator 14b, and is referred to as the F evaporator refrigerant pipe 59.

[0087] The suction pipe 57 (refrigerant flow path FP6 ) can exchange heat with part or all of the R capillary tube 53 a , part or all of the F capillary tube 53 b , and part or all of the defrosting capillary tube 103 in the internal heat exchange portion 58 .

[0088] In addition, the internal heat exchange part 58 only needs to allow the R capillary tube 53a, the F capillary tube 53b, and the defrosting capillary tube 103 to be close to the suction pipe 57 (refrigerant flow path FP6) for heat exchange. In the refrigerator 1 of the first embodiment, the R capillary tube 53a, the F capillary tube 53b, and the defrosting capillary tube 103 are welded to the suction pipe 57 (refrigerant flow path FP6). Through this welding, the metal parts are used for fixed connection, so that the refrigerator 1 improves the heat exchange efficiency.

[0089] In addition, in this embodiment, the refrigerator 1 is described as a configuration using isobutane, which is a flammable refrigerant, as a refrigerant. In addition, the compressor 24 is provided with an inverter and is described as a configuration capable of changing the rotation speed.

[0090] In this embodiment, the defrosting pipe 102 is connected to the outlet 101b and one end of the defrosting capillary tube 103 via the refrigerant piping. In addition, the other end of the defrosting capillary tube 103 is connected to the inflow side of the check valve 104 via the refrigerant piping. Furthermore, the outflow side of the check valve 104, which is the outlet of the refrigerant piping for the defrosting operation, is connected to the above-mentioned confluence portion 105 via the refrigerant piping.

[0091] The three-way valve 101 is the same as the three-way valve 52, and has two outflow ports 101a and 101b, and is a component that can switch the direction of the refrigerant flow. The outflow port 101a of the three-way valve 101 is connected to the external radiator 50a via the refrigerant piping. On the other hand, the outflow port 101b of the three-way valve 101 is connected to the defrosting pipe 102 via the refrigerant piping. In addition, the outlet Out102 of the defrosting pipe 102 is the outlet of the part that performs heat exchange with the F evaporator 14b (freezing evaporator) during the defrosting operation.

[0092] In addition, the flow resistance (pressure loss under the same conditions) of the defrosting capillary tube 103 is set to be lower (smaller) than the flow resistance of the R capillary tube 53a, and the reason will be described later. That is, the flow resistance from the defrosting pipe 102 to the R evaporator 14a is set to be lower (smaller) than the flow resistance from the three-way valve 52 to the R evaporator 14a.

[0093] Fig. 6A , Figure 6B , Figure 6C 1 is an explanatory diagram showing the flow of the refrigerant in the refrigerator 1 of the first embodiment. Specifically, Fig. 6AThis indicates that the refrigerant flows to the R evaporator 14a to cool the refrigerating chamber 2 ( Figure 1 ) during the refrigeration cooling operation (R cooling operation). Figure 6B The refrigerant flows to the F evaporator 14b to the freezing chamber 7 ( Figure 1 ) etc. during the refrigeration cooling operation (F cooling operation). Figure 6C The flow of the refrigerant during the defrosting operation in which the F evaporator 14b is defrosted is shown.

[0094] First, refer to Fig. 6A , the flow of refrigerant during refrigeration and cooling operation is explained. Fig. 6A As shown, in the refrigeration cooling operation, the refrigerant discharged from the compressor 24 flows through the refrigerant flow paths FP1 , FP2 , FP3 , FP4 , and FP6 and returns to the compressor 24 .

[0095] like Fig. 6A As shown, in the refrigeration and cooling operation, the refrigerator 1 opens the three-way valve 101 to the outlet 101a on the side of the heat dissipation mechanism 50 (external radiator 50a). In the refrigerator 1, if the compressor 24 is driven, the refrigerant is compressed to become a high-temperature and high-pressure gas refrigerant. After the high-temperature and high-pressure gas refrigerant passes through the three-way valve 101, it flows through the external radiator 50a, the wall heat dissipation pipe 50b, and the anti-condensation pipe 50c to dissipate heat and become a liquid refrigerant. Then, the refrigerant flows through the dryer 51 to remove moisture, and then reaches the three-way valve 52.

[0096] Furthermore, the refrigerator 1 opens the three-way valve 52 toward the outlet 52a side so that the refrigerant flows toward the outlet 52a side. The refrigerant flowing out of the outlet 52a is decompressed in the R capillary 53a to become a low-temperature and low-pressure gas-liquid two-phase refrigerant, and then reaches the inlet of the R evaporator 14a through the confluence portion 105. In the refrigerator 1, the air is driven from the refrigerating chamber 2 ( Figure 2 ) flows into the R evaporator chamber 8a. The air flowing into the R evaporator chamber 8a exchanges heat with the low-temperature refrigerant in the R evaporator 14a when passing through the R evaporator 14a, and becomes low temperature, and then flows into the refrigerating chamber 2 ( Figure 2 ) is sent out. At this time, the refrigerant is sent out from the box (refrigerating room 2 ( Figure 2 The air in the R evaporator 14a absorbs heat and the enthalpy rises, the dryness increases, and the refrigerant becomes a substantially saturated gas refrigerant. Then, the refrigerant reaches the outlet of the R evaporator 14a, passes through the R gas-liquid separator 54a, and reaches the suction pipe 57. The suction pipe 57 constitutes the refrigerant flow path FP6, and is connected to the compressor 24. The refrigerant flows in the suction pipe 57 (refrigerant flow path FP6) and returns to the compressor 24.

[0097] Next, refer to Figure 6B, the flow of refrigerant during refrigeration and cooling operation is explained. Figure 6B As shown, in the refrigeration and cooling operation, the refrigerant discharged from the compressor 24 flows through the refrigerant flow paths FP1 , FP2 , FP3 , FP5 , and FP6 and returns to the compressor 24 .

[0098] like Figure 6B As shown, in the freezing and cooling operation, the refrigerator 1 opens the three-way valve 101 to the outlet 101a on the side of the heat dissipation mechanism 50 (external radiator 50a) as in the refrigeration and cooling operation. In the refrigerator 1, if the compressor 24 is driven, the refrigerant is compressed to become a high-temperature and high-pressure gas refrigerant. After the high-temperature and high-pressure gas refrigerant passes through the three-way valve 101, it flows through the external radiator 50a, the wall heat dissipation pipe 50b, and the anti-condensation pipe 50c to dissipate heat and become a liquid refrigerant. Then, the refrigerant flows through the dryer 51 to remove moisture and reaches the three-way valve 52.

[0099] Furthermore, unlike the refrigeration and cooling operation, the refrigerator 1 opens the three-way valve 52 to the outlet 52b side so that the refrigerant flows to the outlet 52b side. The refrigerant flowing out of the outlet 52b is decompressed in the F capillary 53b to become a low-temperature and low-pressure gas-liquid two-phase refrigerant, and then reaches the inlet of the F evaporator 14b. In the refrigerator 1, the air is driven from the freezing chamber 7 ( Figure 2 ) and vegetable room 6( Figure 2 ) flows into the F evaporator chamber 8b. The air flowing into the F evaporator chamber 8b exchanges heat with the low-temperature refrigerant in the F evaporator 14b when passing through the F evaporator 14b and becomes low temperature, and then flows into the freezing chamber 7( Figure 2 ) and vegetable room 6( Figure 2 ) is sent out. At this time, the refrigerant is sent out from the box (freezer 7 ( Figure 2 ) and vegetable room 6( Figure 2 The air in the R evaporator 14a absorbs heat and the enthalpy rises, the dryness increases, and the refrigerant becomes a substantially saturated gas refrigerant. Then, the refrigerant reaches the outlet of the F evaporator 14b, passes through the F gas-liquid separator 54b and the check valve 55, and reaches the suction pipe 57 (refrigerant flow path FP6). The suction pipe 57 has a refrigerant confluence portion 56 that makes the downstream side of the R gas-liquid separator 54a and the downstream side of the F gas-liquid separator 54b merge (connect), and becomes a structure that connects the refrigerant confluence portion 56 and the compressor 24. The refrigerant flows in the suction pipe 57 (refrigerant flow path FP6) and returns to the compressor 24.

[0100] exist Fig. 6A as well as Figure 6BIn the cooling operation shown, the refrigerant passes through the suction pipe 57 (refrigerant flow path FP6) and returns to the compressor 24. At this time, the suction pipe 57 (refrigerant flow path FP6) is configured to perform heat exchange with the R capillary tube 53a and the F capillary tube 53b in the internal heat exchange portion 58. Therefore, the refrigerant passing through the suction pipe 57 is heated by the refrigerant in the R capillary tube 53a or the F capillary tube 53b, and returns to the compressor 24 with an increase in enthalpy (increase in temperature).

[0101] The refrigerator 1 is provided with such an internal heat exchanger 58, so that the temperature of the refrigerant sucked into the compressor 24 can be increased. Figure 3 ) in the suction tube 57 ( Figure 3 ) has a higher refrigerant temperature, so condensation and frost on the suction pipe 57 can be prevented. In addition, the refrigerator 1 can reduce the enthalpy of the refrigerant flowing into the R evaporator 14a and the F evaporator 14b by heat exchange. Therefore, the refrigerator 1 can improve the cooling capacity of the R evaporator 14a and the F evaporator 14b. In addition, in the refrigerator 1 using a refrigerant such as isobutane, by providing an internal heat exchange part 58, the cooling efficiency (the ratio of the cooling heat to the input of the compressor 24), that is, the energy-saving performance can also be improved according to the relationship between the ratio of the improvement in cooling capacity obtained by providing the internal heat exchange part 58 and the increase in compression power of the compressor 24.

[0102] Next, refer to Figure 6C , the flow of refrigerant during defrosting operation is explained. Figure 6C As shown, in the defrosting operation, the refrigerant discharged from the compressor 24 flows through the refrigerant flow paths FP1, FP7, FP8, FP4b, and FP6 and returns to the compressor 24. The refrigerant flow path FP4b is a portion of the refrigerant flow path FP4 that connects the junction 105 to the refrigerant junction 56.

[0103] like Figure 6CAs shown, during the defrosting operation, the refrigerator 1 opens the three-way valve 101 to the outlet 101b on the defrosting pipe 102 side. In the refrigerator 1, if the compressor 24 is driven, the refrigerant is compressed to become a high-temperature and high-pressure gas refrigerant. After the high-temperature and high-pressure gas refrigerant passes through the three-way valve 101, it flows through the defrosting pipe 102 and exchanges heat with the F evaporator 14b. As a result, the refrigerator 1 dissipates heat from the gas refrigerant in the defrosting pipe 102 to heat the F evaporator 14b. By this heat dissipation, the temperature of the gas refrigerant decreases and liquefies. The liquefied refrigerant passes through the defrosting capillary 103. At this time, the refrigerant is decompressed by the defrosting capillary 103 to become a low-temperature and low-pressure gas-liquid two-phase refrigerant. After the low-temperature and low-pressure refrigerant passes through the check valve 104, it reaches the inlet of the R evaporator 14a via the confluence portion 105. The low-temperature R evaporator 14a exchanges heat with the surrounding air. As a result, the surrounding air becomes low temperature. The low-temperature ambient air is sent to the refrigerating chamber 2 ( Figure 1 ). Thus, the refrigerator 1 cools the refrigerating chamber 2. Through this heat exchange, the refrigerant in the R evaporator 14a is cooled from the refrigerator (refrigerating chamber 2 ( Figure 1 The air in the R evaporator 14a absorbs heat and the enthalpy rises, the dryness increases, and the refrigerant becomes a substantially saturated gas refrigerant. Then, the refrigerant reaches the outlet of the R evaporator 14a, passes through the R gas-liquid separator 54a, and reaches the suction pipe 57 (refrigerant flow path FP6). Then, the refrigerant flows in the suction pipe 57 (refrigerant flow path FP6) and returns to the compressor 24.

[0104] The flow of the refrigerant from the junction 105 to the compressor 24 during the defrosting operation is similar to that during the refrigeration and cooling operation ( Fig. 6A However, during the defrosting operation, the refrigerant in the suction pipe 57 (refrigerant flow path FP6) mainly exchanges heat with the refrigerant in the defrosting capillary tube 103 via the internal heat exchange portion 58.

[0105] In addition, the flow path resistance R103 ( Figure 6C ) is set to be lower than the flow resistance R53a of the R capillary tube 53a (the refrigeration decompression mechanism). In addition, the flow resistance R1 ( Figure 6C ), which is set to be greater than the flow resistance R2 ( Figure 6C ) is low. In addition, the refrigerant flow path FP4a is a portion of the refrigerant flow path FP4 that connects the three-way valve 52 to the inlet In14a of the R evaporator 14a.

[0106] Figure 7 Yes means Figure 6C The P-h diagram of the refrigeration cycle state during defrosting operation is shown in FIG. Figure 7 In the figure, the vertical axis represents pressure P and the horizontal axis represents specific enthalpy h. Figure 7 Indicates a theoretical cycle that ignores all kinds of losses. In addition, Figure 7 The difference Δq between the two enthalpies shown is the same value (equal). Figure 7 The heat amount q and the power consumption amount wa shown are the energy per 1 kg of the refrigerant, but the description per 1 kg of the refrigerant is omitted.

[0107] exist Figure 7 In FIG. 1 , state C1 indicates the state of the inlet of the compressor 24. In addition, state C2 indicates the state of the outlet of the compressor 24. In addition, state C3 indicates the state of the inlet of the defrosting capillary tube 103. In addition, state C4 indicates the state of the outlet of the defrosting capillary tube 103. In addition, state C5 indicates the state of the outlet of the F evaporator 14b.

[0108] The refrigerant in the state C1 is compressed by the compressor 24 to a condensation pressure P d The state C2. The power consumption of the compressor 24 at this time is wa. The refrigerant in the state C2 dissipates heat equivalent to the heat dissipation q by heat exchange with the F evaporator 14b. H , becoming state C3. The refrigerant in state C3 passes through the defrosting capillary tube 103, and the pressure increases from the condensing pressure P d The refrigerant in state C3 decreases its specific enthalpy by the difference Δq between q3 in state C3 and q4 in state C4 through heat exchange in the internal heat exchange section 58, and reaches state C4. The refrigerant in state C4 absorbs heat by the heat exchange with the R evaporator 14a, and absorbs heat by the amount of heat absorbed q c , reaching state C5. The refrigerant in state C5 passes through the suction pipe 57 and returns to the compressor 24. At this time, the refrigerant in state C5 increases its specific enthalpy by the difference Δq between q1 in state C1 and q5 in state C5 through the heat exchange in the internal heat exchange section 58, and reaches state C1. That is, the refrigerant in state C5 passes through the suction pipe 57 and returns to the inlet of the compressor 24.

[0109] Here, Figure 7 The difference Δq between the two enthalpies shown in FIG. 1 and FIG. 2 becomes the same value (equal). Therefore, the difference (q1-q3) in the specific enthalpy between the state C1 and the state C3 and the heat absorption q c Become the same (equal). In addition, from Figure 7 It can be seen that the heat dissipation q H Become a "q H =(wa+(q1-q3))=(wa+q c)". Therefore, in the theoretical cycle, the heat dissipation used for heating the F evaporator 14b is q H The power consumption wa of the compressor 24 and the heat absorption q of the R evaporator 14a are obtained. c The combined value (wa+q c ). Therefore, the refrigerator 1 can obtain a heat dissipation amount q greater than the power consumption wa of the compressor 24. H (heating capacity).

[0110] The above is the basic method of the refrigerator 1 of the first embodiment.

[0111] <Effect of the defrosting structure of refrigerator 1>

[0112] The following is the Figure 6C The effect of the defrosting structure of the refrigerator 1 of the first embodiment achieved by the refrigeration cycle shown will be described. The defrosting structure of the refrigerator 1 of the first embodiment is a defrosting structure with high energy saving performance compared to a defrosting structure using an electric heater for the following reasons.

[0113] (Reason 1) In the defrosting structure using a general electric heater, the heating amount of the heater used for heating the evaporator is equal to the amount of power consumed. In contrast, in the defrosting structure of the refrigerator 1 of the first embodiment, Figure 7 As shown, the heat dissipation q used by the refrigerator 1 as the heating of the F evaporator 14b H , a greater amount of heat dissipation q can be obtained than the amount of power consumption wa of the compressor 24 H (Heating amount). In addition, in the defrosting structure using an electric heater such as a radiation heater to heat the F evaporator 14b through radiation and air convection, the heat generated is mostly used to heat the surrounding wall surface. Therefore, the heating amount of the F evaporator 14b becomes less relative to the heat generated. In contrast, in the defrosting structure of the refrigerator 1 of the first embodiment, the refrigerant in the defrosting pipe 102 as a heating source directly exchanges heat with the F evaporator 14b. Therefore, the refrigerator 1 can reduce the loss of heat. Compared with the defrosting structure using an electric heater, the defrosting structure of the refrigerator 1 of the first embodiment becomes a defrosting operation with high heating efficiency.

[0114] (Reason 2) In the defrosting structure of the refrigerator 1 of the first embodiment, during the defrosting operation, the heat q is absorbed from the refrigerating chamber 2 via the R evaporator 14a. c Therefore, the defrosting structure of the refrigerator 1 of the first embodiment can be achieved by performing Figure 6C The defrosting operation is performed to carry out the heat load of the refrigerating chamber 2, and it is possible to Fig. 6A The power consumption of the compressor 24 is reduced by performing refrigeration and cooling operation.

[0115] For these reasons, the defrosting structure of the refrigerator 1 of the first embodiment is a defrosting structure with high energy saving performance.

[0116] <Bypass and independent capillary effects in the heat dissipation section>

[0117] The refrigerator 1 of the first embodiment is provided with a defrosting pipe 102 as an independent refrigerant pipe in contact with the F evaporator 14b in order to perform heat exchange with the F evaporator 14b. In addition, the refrigerator 1 of the first embodiment is provided with a defrosting capillary tube 103 as an independent capillary tube. Furthermore, the refrigerator 1 of the first embodiment is provided with the features described later, and in the defrosting operation, the defrosting time is short and the defrosting can be performed with higher heating efficiency.

[0118] In order to clearly and simply explain the effect of the refrigeration cycle of the refrigerator 1 of the first embodiment, first, refer to Figure 8 as well as Fig. 9 , the structure of the refrigerator 1001 having the refrigeration cycle of the first comparative example and the structure of the refrigerator 1002 having the refrigeration cycle of the second comparative example are described. Fig.10 , the states of the refrigeration cycle of the first embodiment, the refrigeration cycle of the first comparative example, and the refrigeration cycle of the second comparative example during the defrosting operation are described. Figure 8 It is a schematic diagram showing a refrigeration cycle (refrigerant flow path) of a first comparative example. Fig. 9 It is a schematic diagram showing a refrigeration cycle (refrigerant flow path) of a second comparative example. Fig.10 : is a P-h diagram showing the defrosting operation of the refrigeration cycle of the first embodiment, the refrigeration cycle of the first comparative example, and the refrigeration cycle of the second comparative example. The refrigeration cycle of the first comparative example and the refrigeration cycle of the second comparative example are based on the refrigeration cycle of the first embodiment ( Figure 5 ) and a hypothetical refrigeration cycle designed.

[0119] like Figure 8 As shown, if the refrigeration cycle of the first comparative example is compared with the refrigeration cycle of the first embodiment ( Figure 5 ) are different in the following aspects: the three-way valve 101 is not provided immediately after the compressor 24 ( Figure 5 ), but a three-way valve 201 is provided between the outlet of the wall heat dissipation pipe 50b and the inlet of the anti-condensation pipe 50c. The three-way valve 201 and the three-way valve 101 ( Figure 5) is the same as the refrigerant control mechanism that switches the direction of the refrigerant flow when performing cooling operation (refrigeration cooling operation and freezing cooling operation) and when performing defrosting operation. The three-way valve 201 allows the refrigerant to flow to the condensation prevention pipe 50c side when performing cooling operation (refrigeration cooling operation and freezing cooling operation), and on the other hand, allows the refrigerant to flow to the defrosting pipe 102 side when performing defrosting operation. The refrigeration cycle of the first comparative example has the following structure: the refrigerant ejected from the compressor 24 passes through a part of the heat dissipation mechanism (the external radiator 50a and the wall heat dissipation pipe 50b) and is then transported to the defrosting pipe 102.

[0120] In addition, if the refrigeration cycle of the first comparative example is compared with the refrigeration cycle of the first embodiment ( Figure 5 ) are different in the following aspects: a defrosting capillary 203 is provided to replace the defrosting capillary 103 ( Figure 5 ). The defrosting capillary tube 203 is a capillary tube having a flow path resistance equivalent to that of the R capillary tube 53a.

[0121] In addition, if the refrigeration cycle of the first comparative example is compared with the refrigeration cycle of the first embodiment ( Figure 5 ) compared, the structure becomes as follows: the refrigerant flow paths FP11 to FP18 are provided to replace the refrigerant flow paths FP1 to FP8.

[0122] The refrigerant flow path FP11 is configured to connect the compressor 24 to the three-way valve 101 .

[0123] The refrigerant flow path FP12 is configured to connect the three-way valves 101 to 201 through the external radiator 50 a and the wall surface radiating pipe 50 b of the radiating mechanism 50 .

[0124] The refrigerant flow path FP13 is configured to connect the three-way valve 201 to the three-way valve 52 via the condensation prevention pipe 50 c of the heat dissipation mechanism 50 .

[0125] The refrigerant flow path FP14 is configured to connect the three-way valve 52 to the refrigerant junction 56 through the R capillary tube 53 a , the R evaporator 14 a , and the R gas-liquid separator 54 a .

[0126] The refrigerant flow path FP15 is configured to connect the three-way valve 52 to the refrigerant junction 56 through the F capillary tube 53 b , the F evaporator 14 b , the F gas-liquid separator 54 b , and the check valve 55 .

[0127] Refrigerant flow path FP16 is configured to connect refrigerant junction 56 to compressor 24 .

[0128] The refrigerant flow path FP17 is configured to connect the three-way valve 201 to the defrosting pipe 102 .

[0129] The refrigerant flow path FP18 is configured to connect the defrost pipe 102 to the junction 105 via the defrost capillary tube 103 and the check valve 104 .

[0130] In the refrigeration cycle of the first comparative example, other parts are similar to the refrigeration cycle of the first embodiment ( Figure 5 )same.

[0131] On the other hand, Fig. 9 As shown, if the refrigerator of the second comparative example is compared with the refrigeration cycle of the first embodiment ( Figure 5 ) are compared, the following points are different: a check valve 204 and refrigerant flow paths FP21 to FP28 are provided to replace the defrosting capillary 103, the check valve 104 and the refrigerant flow paths FP1 to FP8.

[0132] The refrigerant flow path FP21 is configured to connect the compressor 24 to the three-way valve 101 .

[0133] The refrigerant flow path FP22 is configured to connect the three-way valve 101 to the condensation prevention pipe 50 c of the heat dissipation mechanism 50 through the external radiator 50 a and the wall surface heat dissipation pipe 50 b of the heat dissipation mechanism 50 .

[0134] The refrigerant flow path FP23 is configured to connect the condensation prevention pipe 50 c of the heat dissipation mechanism 50 to the three-way valve 52 via the dryer 51 .

[0135] The refrigerant flow path FP24 is configured to connect the three-way valve 52 to the refrigerant junction 56 through the R capillary tube 53 a , the R evaporator 14 a , and the R gas-liquid separator 54 a .

[0136] The refrigerant flow path FP25 is configured to connect the three-way valve 52 to the refrigerant junction 56 through the F capillary tube 53 b , the F evaporator 14 b , the F gas-liquid separator 54 b , and the check valve 55 .

[0137] Refrigerant flow path FP26 is configured to connect the refrigerant junction 56 to the compressor 24 .

[0138] The refrigerant flow path FP27 is configured to connect the three-way valve 101 to the defrosting pipe 102 .

[0139] Refrigerant flow path FP28 is configured to connect defrost pipe 102 to junction 106 via check valve 204. Junction 106 is a location where the refrigerant pipe for cooling operation (refrigerant flow path FP22) and the refrigerant pipe for defrosting operation (refrigerant flow path FP28) merge (connect).

[0140] The refrigeration cycle of the second comparative example is configured such that the refrigerant passes through the defrosting pipe 102 and flows to the upstream of the dryer 51 and the three-way valve 52. That is, the refrigeration cycle of the second comparative example is configured such that the refrigerant passes through the R capillary tube 53a and flows to the R evaporator 14a (refrigeration cooler) during the defrosting operation.

[0141] In the refrigeration cycle of the second comparative example, other parts are similar to the refrigeration cycle of the first embodiment ( Figure 5 )same.

[0142] Below, refer to Fig.10 , for the refrigeration cycle of the first embodiment ( Figure 5 ), the refrigeration cycle of the first comparative example ( Figure 8 ), the refrigeration cycle of the second comparative example ( Fig. 9 ) will be described below. In addition, here, the description will be made assuming that the outside air temperature is sufficiently higher than the melting point (0° C.) of frost (for example, 20° C. or higher).

[0143] In addition, Fig.10 Among the various parameters shown, the parameters with "1" at the end of the symbol are the same as the refrigeration cycle of the first comparative example ( Figure 8 ) corresponding parameters. In addition, the parameters marked with "2" at the end of the symbol are the parameters corresponding to the refrigeration cycle of the second comparative example ( Fig. 9 ) corresponding parameters. The parameters marked with "3" at the end of the symbol are the parameters corresponding to the refrigeration cycle ( Figure 5 ) corresponding to the parameter.

[0144] First, regarding the heating efficiency of each refrigeration cycle, the refrigeration cycle of the first comparative example ( Figure 8 ), the refrigeration cycle of the second comparative example ( Fig. 9 ) and the refrigeration cycle of the first embodiment ( Figure 5 ) for comparison.

[0145] Refrigeration cycle of the first comparative example ( Figure 8 ) dissipates heat through the external radiator 50a and the wall heat dissipation pipe 50b during defrosting operation. Therefore, in the refrigeration cycle of the first comparative example, the condensation temperature of the refrigerant during defrosting operation is higher than the outside air temperature and becomes close to the value during normal cooling operation. In addition, the refrigerant is depressurized by the defrosting capillary 203 having the same flow resistance as the R capillary 53a. Therefore, in the refrigeration cycle of the first comparative example, the condensation pressure P of the refrigerant during defrosting operation is d1 and evaporation pressure P s1 Both are values ​​close to those during normal cooling operation.

[0146] On the other hand, the refrigeration cycle of the second comparative example ( Fig. 9) During the defrosting operation, the F evaporator 14b (freezing cooler) with frost at a lower temperature than outside the box exchanges heat with the refrigerant. Therefore, in the refrigeration cycle of the second comparative example, the condensation temperature of the refrigerant during the defrosting operation tends to be lower. Compared with the cooling operation in which heat is dissipated to the outside of the box, the condensation pressure P of the refrigerant during the defrosting operation is lower than that during the cooling operation in which heat is dissipated to the outside of the box. d2 In addition, in the refrigeration cycle of the second comparative example, the condensation pressure P of the refrigerant during the defrosting operation is d2 In the lower state, the refrigerant is depressurized by the R capillary 53a which is the same as that in the cooling operation. Therefore, in the refrigeration cycle of the second comparative example, the evaporation pressure P of the refrigerant in the defrosting operation is s2 It is also easy to go low.

[0147] In contrast, the refrigeration cycle of the first embodiment ( Figure 5 ) makes the refrigeration cycle of the second comparative example ( Fig. 9 ) The same F evaporator 14b (refrigeration cooler) exchanges heat with the refrigerant. Therefore, in the refrigeration cycle of the first embodiment, the condensation temperature of the refrigerant during the defrosting operation tends to be low. The refrigeration cycle of the first embodiment can reduce the condensation pressure P of the refrigerant during the defrosting operation. d3 Here, although the refrigeration cycle of the first embodiment has a condensing pressure P d3 However, the defrosting capillary tube 103 having a lower flow resistance than the F capillary tube 53b is used to reduce the pressure. Therefore, in the refrigeration cycle of the first embodiment, the evaporation pressure P of the refrigerant during the defrosting operation is s3 Compared with the refrigeration cycle of the second comparative example ( Fig. 9 ) during defrosting operation. s2 The refrigeration cycle of the first embodiment can make the condensation pressure of the refrigerant during the defrosting operation d3 Relatively low, and can make the evaporation pressure P s3 Relatively high, and can reduce the evaporation pressure P s and condensing pressure P d difference.

[0148] Generally, if the evaporation pressure P s and condensing pressure P d The greater the difference in , the greater the power consumption wa of the compressor 24 per 1 kg of refrigerant. Fig.10 It can be seen that the power consumption wa of the compressor 24 per 1 kg of refrigerant is Figure 5 ) has the smallest power consumption w3.

[0149] In addition, in the refrigeration cycle ( Figure 8), the refrigerant that has radiated heat through the external radiator 50a and the wall heat dissipation pipe 50b reaches the defrosting pipe 102. Here, the state of the inlet of the defrosting pipe 102 is referred to as state C. 61 The heat dissipated by the external radiator 50a and the wall heat dissipation pipe 50b is defined as the heat dissipation amount q LOSS1 (loss amount). Then, through this heat dissipation q LOSS1 , State C 61 The refrigeration cycle of the first embodiment ( Figure 5 ) is less than the state C2 at the inlet of the defrosting pipe 102. In addition, the refrigeration cycle ( Figure 8 ) in the state C of the outlet of the defrosting pipe 102 31 The specific enthalpy under the refrigeration cycle of the first embodiment ( Figure 5 ) in the state C of the outlet of the defrosting pipe 102 33 Therefore, the refrigeration cycle of the first embodiment ( Figure 5 ) can make the heat dissipation q LOSS1 The heat dissipation of the defrosting pipe 102 is q H1 decline.

[0150] In addition, the refrigeration cycle of the second comparative example ( Fig. 9 ), the pressure increase by the compressor 24 is relatively large. Therefore, the refrigeration cycle ( Fig. 9 ) of the compressor 24 and the inlet of the defrosting pipe 102. 22 The specific enthalpy of the refrigeration cycle under the first embodiment is ( Figure 5 )'s entry state C 22 In addition, the refrigeration cycle of the second comparative example ( Fig. 9 ) of the defrosting pipe 102 H2 It is also better than the refrigeration cycle of the first embodiment ( Figure 5 ) of the defrosting pipe 102 H3 However, the heat dissipation per 1kg of refrigerant is q H2 With q H3 The difference is relatively small.

[0151] In the first comparative example, the second comparative example, and the first embodiment, if the heat dissipation q of the defrosting pipe 102 is H (heating amount) compared, it becomes "q H2 ≈q H3 >q H1 Therefore, if the power consumption wa consumed by the compressor 24 is compared, it becomes "w1≈w2>w3". In addition, regarding the heating efficiency (heat dissipation q of the defrosting pipe 102), H(heating amount) relative to the amount of power consumed by the compressor 24) , the refrigeration cycle ( Figure 5 ) is the highest. The refrigeration cycle of the first embodiment ( Figure 5 ) and a refrigerator 1001 ( Figure 8 ) and a refrigerator 1002 having a refrigeration cycle of the second comparative example ( Fig. 9 ) compared to conventional heating systems, defrosting can be performed with higher heating efficiency.

[0152] Next, the heat dissipation q of the defrosting pipe 102 H (heating amount), for the refrigeration cycle of the first comparative example ( Figure 8 ), the refrigeration cycle of the second comparative example ( Fig. 9 ) and the refrigeration cycle of the first embodiment ( Figure 5 ) is used for comparison. The heat dissipation q of the defrosting pipe 102 H (Heating amount) is a parameter that affects the defrosting time. Heat dissipation q of the defrosting pipe 102 H The greater the amount of heating, the shorter the defrosting time can be.

[0153] Furthermore, since the F evaporator 14 b does not perform freezing and cooling during the defrosting time, the defrosting time is shortened, and the refrigerator 1 suppresses the time during which the F evaporator 14 b does not perform freezing and cooling, thereby suppressing the temperature fluctuation of the storage room.

[0154] Here, the heat dissipation amount q of the defrosting pipe 102 is H The (heating amount) and the power consumption wa consumed by the compressor 24 are, as mentioned above, the heating amount and power consumption per 1 kg of refrigerant, and the unit is [J / kg]. On the other hand, the actual heating amount per unit time and the power consumption of the compressor 24, which are in [W], depend on the refrigerant circulation amount. Specifically, if the refrigerant circulation amount [kg / s] per 1 second is G, then the actual heat dissipation Q of the defrosting pipe 102 considering the refrigerant circulation amount G is H Become a "Q H =q H ×G”, the amount of power actually consumed by the compressor 24 is W A24 Become a "W A24 =wa×G”.

[0155] Here, the refrigerant circulation amount G, if the volumetric efficiency is constant, is mainly determined by the pressing amount and rotation speed of the piston of the compressor 24, and the density of the refrigerant flowing into the compressor 24. The density of the refrigerant flowing into the compressor 24 is mainly determined by the pressure and temperature of the refrigerant flowing into the compressor 24. In addition, the refrigerant flowing into the compressor 24 is a gas refrigerant, so if the refrigerant pressure becomes higher, the refrigerant density becomes higher, and on the other hand, if the refrigerant temperature becomes higher, the refrigerant density becomes lower.

[0156] Here, assuming that there is no pressure loss other than the capillary tube, the pressure of the refrigerant flowing into the compressor 24 can be replaced by the evaporation pressure P s About evaporation pressure P s , as described above, the refrigeration cycle ( Figure 5 ) evaporation pressure P s3 In comparison, the refrigeration cycle of the second comparative example ( Fig. 9 ) evaporation pressure P s2 On the other hand, it is considered that the refrigerant temperature will not have a large difference. Therefore, when the piston pressing amount and rotation speed of the compressor 24 are the same, the refrigeration cycle of the second comparative example ( Fig. 9 ) and the refrigerant circulation amount G2 of the refrigeration cycle of the first embodiment ( Figure 5 ) is less than G3. H2 ≈q H3 Therefore, considering the actual heat dissipation Q of the defrosting pipe 102 of the refrigerant circulation volume G H Become a "Q H3 >Q H2 ". In addition, in the refrigeration cycle of the first comparative example ( Figure 8 ), the refrigeration cycle of the second comparative example ( Fig. 9 ) and the refrigeration cycle of the first embodiment ( Figure 5 ), the state of the refrigerant flowing into the compressor 24 is the same. Figure 8 ), the refrigeration cycle of the second comparative example ( Fig. 9 ) and the refrigeration cycle of the first embodiment ( Figure 5 ), the refrigerant circulation amount G (i.e., the refrigerant circulation amount G1, G3) is also the same. In addition, as described above, due to the heat dissipation amount q H (heating amount) becomes "q H3 >q H1 Therefore, the actual heat dissipation of the defrosting pipe 102 is Q H Also known as "Q H3 >Q H1 ”.

[0157] Thus, the refrigeration cycle ( Figure 5 ) and the refrigeration cycle of the first comparative example ( Figure 8 ) and the refrigeration cycle of the second comparative example ( Fig. 9 ) compared to the heat dissipation Q of the defrosting pipe 102 that heats the F evaporator 14b. H Therefore, the refrigeration cycle of the first embodiment ( Figure 5 ) can shorten the defrost time during defrost operation.

[0158] In addition, in the refrigeration cycle ( Figure 5 ), a defrosting capillary 103 (thin diameter tube) is used to generate a pressure difference between the heat dissipation side and the heat absorption side. However, the frost can be melted as long as the temperature of the heat dissipation side exceeds the melting temperature of the frost (0°C). In addition, the heat absorption from the refrigerator 2 can be absorbed as long as the temperature of the evaporation side is lower than that of the refrigerator 2 (about 4°C on average, about 10°C at high temperature). Therefore, a large pressure difference is not required. Therefore, as long as the structure is used to sufficiently reduce the condensation temperature, the refrigeration cycle of the first embodiment ( Figure 5 ) It is also possible to use a structure in which there is basically no pressure difference between the heat dissipation side and the heat absorption side due to the pressure loss caused in the refrigerant piping without using the defrosting capillary tube 103 such as a narrow-diameter tube.

[0159] In addition, the refrigeration cycle ( Figure 5 ) and the refrigeration cycle of the first comparative example ( Figure 8 ) is different from the first embodiment, and the heat dissipation mechanism 50 (especially the external radiator 50a and the wall heat dissipation pipe 50b) is bypassed during the defrosting operation. Figure 5 ) suppresses heat dissipation from the compressor 24 to the defrosting pipe 102, suppresses heat dissipation to the outside of the box, and increases the specific enthalpy when the defrosting pipe 102 flows. Figure 5 ) can suppress the reduction of heat dissipation qH (heating amount), etc., and thus can improve the heating efficiency. However, the refrigeration cycle ( Figure 5 ) does not necessarily have to completely suppress the heat dissipation outside the defrosting pipe 102. In addition, the refrigeration cycle ( Figure 5 ) is provided with a three-way valve 101, which switches between cooling operation and defrosting operation before the flow of the foamed polyurethane from the compressor 24 to the wall heat dissipation pipe 50b. Generally, the heat dissipation of the refrigerator is mainly through the wall heat dissipation pipe 50b, so the refrigerant is made to flow in a manner that bypasses the wall heat dissipation pipe 50b, so that the refrigeration cycle of the first embodiment ( Figure 5 ) can efficiently suppress heat dissipation between the compressor 24 and the defrost pipe 102.

[0160] In addition, for example, the refrigeration cycle ( Figure 5) By providing the three-way valve 101 in the machine chamber 39 instead of in the foamed polyurethane, it is possible to improve the ease of manufacturing or the ease of replacement in the event of a failure.

[0161] <Effects of the internal heat exchange section 58>

[0162] The refrigerator 1 of the first embodiment has an internal heat exchanger 58. Thus, the refrigerator 1 of the first embodiment can increase the temperature of the refrigerant sucked into the compressor 24, and can prevent the refrigerant in the machine room 39 from being sucked into the suction pipe 57 ( Figure 3 ) of condensation and frost.

[0163] In addition, from Figure 7 It can be seen that the refrigerator 1 of the first embodiment can increase the enthalpy of the refrigerant (state C1) sucked into the compressor 24 by the difference Δq described above. Thus, the refrigerator 1 of the first embodiment can increase the enthalpy of the state C2 of the refrigerant protruding from the compressor 24. Thus, the refrigerator 1 of the first embodiment can increase the heat dissipation (heating amount) of the refrigerant used for heating the F evaporator 14b (freezing cooler).

[0164] In addition, the refrigerator 1 of the first embodiment can also improve the heating efficiency of refrigerants such as isobutane (the ratio of the heating amount in the F evaporator 14b to the amount of power consumed), that is, improve energy-saving performance, based on the relationship between the ratio of the increase in the heat dissipation (heating amount) and the increase in the compression power of the compressor 24.

[0165] Furthermore, the refrigerator 1 of the first embodiment also cools the refrigerating chamber 2 during the defrosting operation by an amount of heat absorption q c , even if the cooling amount q c , Δq is also increased by the internal heat exchanger 58. That is, the refrigerator 1 of the first embodiment can obtain the effects of improving the cooling capacity and energy saving performance of the internal heat exchanger 58 described in connection with the cooling operation.

[0166] <Main Features of Refrigerator 1 of First Embodiment>

[0167] (1) Figure 6C As shown, the refrigerator 1 of the first embodiment includes a refrigerating chamber 2 ( Figure 1 )、Freezer 7( Figure 1), compressor 24, heat dissipation mechanism 50, R evaporator 14a (refrigeration cooler), F evaporator 14b (freezing cooler), and defrosting pipe 102. The compressor 24 is a component that compresses the refrigerant. The heat dissipation mechanism 50 is a component that releases heat from the refrigerant. The R evaporator 14a is a refrigeration evaporator that evaporates the refrigerant during the refrigeration cooling operation of cooling the refrigerating chamber 2. The F evaporator 14b is a freezing evaporator that evaporates the refrigerant during the freezing cooling operation of cooling the freezing chamber 7. The defrosting pipe 102 is a component that exchanges heat with the F evaporator 14b during the defrosting operation. The defrosting operation is an operation to remove frost attached to the F evaporator 14b by causing the refrigerant ejected from the compressor 24 to flow in the order of the defrosting pipe 102, the R evaporator 14a, and the compressor 24. The flow resistance R1 of the refrigerant path FP8 connecting the outlet Out102 of the defrost pipe 102 to the inlet In14a of the R evaporator 14a is set to be lower than the flow resistance R2 of the refrigerant paths FP3 and FP4a connecting the outlet Out50 of the heat dissipation mechanism 50 to the inlet In14a of the R evaporator 14a.

[0168] The refrigerator 1 of the first embodiment is set such that the flow resistance R1 of the refrigerant path FP8 is lower than the flow resistance R2 of the refrigerant paths FP3 and FP4. Therefore, the refrigerator 1 of the first embodiment can heat the refrigerant ejected from the compressor 24 by the F evaporator 14b while flowing smoothly during the defrosting operation, and the amount of refrigerant used for defrosting can be increased. The refrigerator 1 of the first embodiment can perform defrosting in a short time and with higher heating efficiency during the defrosting operation.

[0169] (2) Figure 6CAs shown, the refrigerator 1 of the first embodiment further includes a refrigerant flow path FP, an R capillary tube 53a, an F capillary tube 53b, a three-way valve 52, and a three-way valve 101. The refrigerant flow path FP is a flow path for the refrigerant to flow. The R capillary tube 53a is a refrigeration pressure reducing mechanism that reduces the pressure of the refrigerant during refrigeration cooling. The F capillary tube 53b is a freezing pressure reducing mechanism that reduces the pressure of the refrigerant during freezing cooling. The three-way valve 52 is a first refrigerant control mechanism that switches the direction of the refrigerant ejected from the heat dissipation mechanism 50 to either the direction of the R capillary tube 53a (refrigeration pressure reducing mechanism) or the direction of the F capillary tube 53b (freezing pressure reducing mechanism). The three-way valve 101 is provided between the compressor 24 and the three-way valve 52 (first refrigerant control mechanism), and is a second refrigerant control mechanism that switches the direction of the refrigerant ejected from the compressor 24 to either the direction of the heat dissipation mechanism 50 or the direction of the defrosting pipe 102. The refrigerant flow path FP is configured such that, during the refrigeration cooling operation, the refrigerant discharged from the compressor 24 flows in the order of the three-way valve 101 (second refrigerant control mechanism), the heat dissipation mechanism 50, the three-way valve 52 (first refrigerant control mechanism), the R capillary tube 53a (refrigeration pressure reducing mechanism), the R evaporator 14a, and the compressor 24. In addition, the refrigerant flow path FP is configured such that, during the freezing cooling operation, the refrigerant discharged from the compressor 24 flows in the order of the three-way valve 101 (second refrigerant control mechanism), the heat dissipation mechanism 50, the three-way valve 52 (first refrigerant control mechanism), the F capillary tube 53b (freezing pressure reducing mechanism), the F evaporator 14b, and the compressor 24. In addition, the refrigerant flow path FP is configured such that, during the defrosting operation, the refrigerant discharged from the compressor 24 flows in the order of the three-way valve 101 (second refrigerant control mechanism), the defrosting pipe 102, the R evaporator 14a, and the compressor 24.

[0170] The refrigerator 1 of the first embodiment can realize a structure that performs defrosting in a short time and with higher heating efficiency.

[0171] (3) Figure 6C As shown, the refrigerator 1 of the first embodiment further includes a confluence portion 105 and a check valve 104. The confluence portion 105 is a portion where the pipe on the refrigerant path FP4 connecting the compressor 24 to the R evaporator 14a and the pipe on the refrigerant path FP8 connecting the defrosting pipe 102 to the R evaporator 14a merge (connect). The check valve 104 is a component that suppresses the refrigerant from flowing into the defrosting pipe 102 during cooling operation. The check valve 104 is provided between the confluence portion 105 and the defrosting pipe 102.

[0172] The refrigerator 1 of the first embodiment is provided with a check valve 104 between the confluence portion 105 and the F evaporator 14b. The refrigerator 1 of the first embodiment can suppress the movement (reverse movement) of the refrigerant toward the F evaporator 14b (freezing and cooling evaporator) during cooling operation. Thus, the refrigerator 1 of the first embodiment can prevent the shortage of refrigerant during cooling operation.

[0173] (4) Figure 4A As shown, in the refrigerator 1 of the first embodiment, the defrosting pipe 102 is expanded so as to efficiently contact the fins provided on the F evaporator 14b.

[0174] The refrigerator 1 of the first embodiment can efficiently contact the fins of the F evaporator 14b with the defrosting pipe 102. Therefore, the refrigerator 1 of the first embodiment can increase the heat exchange amount between the fins of the F evaporator 14b and the refrigerant in the defrosting pipe 102. The refrigerator 1 of the first embodiment can perform defrosting in a short time and with higher heating efficiency during defrosting operation.

[0175] (5) Figure 6C As shown, the refrigerator 1 of the first embodiment further includes a defrosting capillary tube 103 (defrosting pressure reducing mechanism), which is provided between the defrosting pipe 102 and the R evaporator 14a and reduces the pressure of the refrigerant during the defrosting operation. The flow path resistance R103 of the defrosting capillary tube 103 (defrosting pressure reducing mechanism) is set to be lower than the flow path resistance R53a of the R capillary tube 53a (refrigeration pressure reducing mechanism).

[0176] The refrigerator 1 of the first embodiment is set such that the flow resistance R103 of the defrosting capillary tube 103 (defrosting pressure reducing mechanism) is lower than the flow resistance R53a of the R capillary tube 53a (refrigeration pressure reducing mechanism). Therefore, the refrigerator 1 of the first embodiment can increase the amount of refrigerant used for defrosting and increase the heat dissipation (heating amount) of the refrigerant. The refrigerator 1 of the first embodiment can perform defrosting in a short time and with higher heating efficiency.

[0177] (6) Figure 6C As shown, the refrigerator 1 of the first embodiment further includes an internal heat exchanger 58 (heat exchanger). The internal heat exchanger 58 (heat exchanger) is a component that performs heat exchange between the refrigerant flow paths FP3 and FP4a from the outlet Out102 of the defrost pipe 102 to the inlet In14a of the R evaporator 14a and the refrigerant flow path FP8 from the R evaporator 14a to the compressor 24 during the defrosting operation.

[0178] The refrigerator 1 of the first embodiment can heat the refrigerant returning to the compressor 24 by using the internal heat exchange part 58. Therefore, the refrigerator 1 of the first embodiment can increase the heat amount of the refrigerant returning to the compressor 24 and improve energy saving. The refrigerator 1 of the first embodiment can perform defrosting in a short time and with higher heating efficiency.

[0179] (7) Figure 6C As shown, the refrigerator 1 of the first embodiment includes a refrigerating chamber 2 ( Figure 1 )、Freezer 7( Figure 1 ), compressor 24, R evaporator 14a (refrigeration cooler), F evaporator 14b (freezing cooler), refrigerant flow path FP, R capillary tube 53a (refrigeration pressure reducing mechanism), and F capillary tube 53b (freezing pressure reducing mechanism). The compressor 24 is a component that compresses the refrigerant. The heat dissipation mechanism 50 is a component that releases heat from the refrigerant. The R evaporator 14a is a refrigeration evaporator that evaporates the refrigerant during the refrigeration cooling operation of cooling the refrigerating chamber 2. The F evaporator 14b is a freezing evaporator that evaporates the refrigerant during the freezing cooling operation of cooling the freezing chamber 7. The refrigerant flow path FP is a flow path for the refrigerant to flow. The R capillary tube 53a is a refrigeration pressure reducing mechanism that reduces the pressure of the refrigerant during refrigeration cooling. The F capillary tube 53b is a freezing pressure reducing mechanism that reduces the pressure of the refrigerant during freezing cooling. The refrigerant flow path FP is configured to allow the refrigerant to flow while bypassing a portion or all of the R capillary tube 53a (the decompression mechanism for refrigeration) and the F capillary tube 53b (the decompression mechanism for freezing) during the defrosting operation. Figure 6C In the example shown, the refrigerant flow path FP is configured to allow the refrigerant to flow through the defrost capillary 103 (defrost pressure reducing mechanism) instead of bypassing the entire R capillary 53a and the F capillary 53b during the defrost operation. In addition, the defrost operation is an operation in which the refrigerant ejected from the compressor 24 exchanges heat with the F evaporator 14b and then flows through the R evaporator 14a and the compressor 24 in this order, thereby removing frost attached to the F evaporator 14b.

[0180] The refrigerator 1 of the first embodiment can adjust the decompression amount of the refrigerant during the defrosting operation. Therefore, the refrigerator 1 of the first embodiment can increase the amount of refrigerant used for defrosting. The refrigerator 1 of the first embodiment can perform defrosting in a short time and with higher heating efficiency during the defrosting operation.

[0181] In addition, if Fig.11 As shown, the refrigerator 1A of the second embodiment described later is different from the refrigerator 1 ( Figure 6C ) is the same as that of the refrigerator 1A of the second embodiment described later ( Fig.11 ) Equipped with 2 cold storage rooms ( Figure 1)、Freezer 7( Figure 1 ), compressor 24, R evaporator 14a (refrigeration cooler), F evaporator 14b (freezing cooler), refrigerant flow path FP, R capillary tube 53a (refrigeration decompression mechanism), and F capillary tube 53b (freezing decompression mechanism). In addition, in the refrigerator 1A ( Fig.11 ) in which the refrigerant flow path FP is configured to bypass a portion or all of the R capillary tube 53a (the decompression mechanism for refrigeration) and the F capillary tube 53b (the decompression mechanism for freezing) to allow the refrigerant to flow during the defrosting operation. Fig.11 In the example shown, the refrigerant flow path FP is configured to allow the refrigerant to flow through the defrosting capillary 103 (defrosting pressure reducing mechanism) instead of bypassing the R capillary 53a and the F capillary 53b during the defrosting operation. Figure 6C ) is the same as the conventional method, which can increase the amount of refrigerant used for defrosting, and can perform defrosting in a shorter time and with higher heating efficiency during defrosting operation.

[0182] (8) Figure 6C As shown, the refrigerator 1 of the first embodiment is also provided with a defrosting capillary tube 103 (defrosting pressure reducing mechanism) and a confluence portion 105. The defrosting capillary tube 103 is a defrosting pressure reducing mechanism that reduces the pressure of the refrigerant during the defrosting operation. The confluence portion 105 is a portion where the pipe on the refrigerant path FP4 connecting the compressor 24 to the R evaporator 14a and the pipe on the refrigerant path FP8 connecting the F evaporator 14b to the R evaporator 14a are merged (connected). The defrosting capillary tube 103 is arranged in the flow path to the confluence portion 105 where the refrigerant reaches after heat exchange with the F evaporator 14b during the defrosting operation. In addition, the R capillary tube 53a is arranged between the compressor 24 and the confluence portion 105 on the refrigerant path FP4 connecting the compressor 24 to the R evaporator 14a during the cooling operation. The flow path resistance R103 of the defrosting capillary tube 103 is set to be lower than the flow path resistance R53a of the R capillary tube 53a.

[0183] The refrigerator 1 of the first embodiment is set such that the flow resistance R103 of the defrosting capillary tube 103 is lower than the flow resistance R53a of the R capillary tube 53a. Therefore, the refrigerator 1 of the first embodiment can increase the amount of refrigerant used for defrosting and increase the heat dissipation (heating amount) of the refrigerant. In this way, the refrigerator 1 of the first embodiment can perform defrosting in a short time and with higher heating efficiency during defrosting operation.

[0184] As described above, according to the refrigerator 1 of the first embodiment, defrosting can be performed in a short time and with higher heating efficiency.

[0185] [Second embodiment]

[0186] The refrigerator 1 ( Figure 5 ) is provided with a defrost pipe 102, and heat exchange is performed between the F evaporator 14b and the refrigerant in the defrost pipe 102. In contrast, in the second embodiment, the defrost pipe 102 is removed, and the refrigerant is instead allowed to flow into the inside of the F evaporator 14b, thereby providing a refrigerator 1A ( Fig.11 ).

[0187] Below, refer to Fig.11 , the structure of the refrigerator 1A of the second embodiment is described. Fig.11 This is a schematic diagram showing the structure of the refrigeration cycle (refrigerant flow path) in the refrigerator 1A of the second embodiment. The refrigerator 1A of the second embodiment has the following structure: by allowing the high-temperature refrigerant ejected from the compressor 24 during the defrosting operation to flow to the F evaporator refrigerant pipe 59 of the F evaporator 14b used during the cooling operation, the frost attached to the F evaporator 14b is heated and thawed.

[0188] like Fig.11 As shown, if the refrigerator 1A of the second embodiment is compared with the refrigerator 1 ( Figure 5 ) are different in the following aspects.

[0189] (1) Refrigerant flow paths FP31 to FP38 are provided instead of the defrosting pipe 102 and the refrigerant flow paths FP1 to FP8.

[0190] (2) The two-way valve 112 is provided between the F gas-liquid separator 54 b and the check valve 55 .

[0191] The refrigerant flow path FP31 is configured to connect the compressor 24 to the three-way valve 101 .

[0192] The refrigerant flow path FP32 is configured to connect the three-way valve 101 to the condensation prevention pipe 50 c of the heat dissipation mechanism 50 through the external radiator 50 a and the wall surface heat dissipation pipe 50 b of the heat dissipation mechanism 50 .

[0193] The refrigerant flow path FP33 is configured to connect the condensation prevention pipe 50 c of the heat dissipation mechanism 50 to the three-way valve 52 via the dryer 51 .

[0194] The refrigerant flow path FP34 is configured to connect the three-way valve 52 to the refrigerant confluence portion 113 through the R capillary tube 53a, the R evaporator 14a, and the R gas-liquid separator 54a. The refrigerant confluence portion 113 is a portion where the refrigerant flow path FP34 and the refrigerant flow path FP35 merge (connect). The refrigerant flow path FP34 includes: a refrigerant flow path FP34a connecting the three-way valve 52 to the confluence portion 105; and a refrigerant flow path FP34b connecting the confluence portion 105 to the refrigerant confluence portion 113.

[0195] The refrigerant flow path FP35 is configured to connect the three-way valve 52 to the refrigerant confluence portion 113 through the F capillary tube 53b, the F evaporator 14b, the F gas-liquid separator 54b, and the check valve 55. The refrigerant flow path FP35 includes: a refrigerant flow path FP35a connecting the three-way valve 52 to the confluence portion 110; and a refrigerant flow path FP35b connecting the confluence portion 110 to the refrigerant confluence portion 113.

[0196] The refrigerant flow path FP36 is configured to connect the refrigerant junction 113 to the compressor 24. The refrigerator 1A has a structure in which the R capillary tube 53a, the F capillary tube 53b, and the defrosting capillary tube 103 can exchange heat with the refrigerant flow path FP36 (suction pipe 57) in the internal heat exchange part 58.

[0197] The refrigerant flow path FP37 is configured to connect the three-way valve 101 to the merging portion 110. The merging portion 110 is a portion where the refrigerant flow path FP37 and the refrigerant flow path FP35 merge (are connected).

[0198] The refrigerant flow path FP38 is configured to pass through the defrosting capillary tube 103 and the check valve 104, and connect the branching portion 111 to the converging portion 105. The branching portion 111 is a portion configured to branch the refrigerant flow path FP38 from the refrigerant flow path FP35. The order of the defrosting capillary tube 103 and the check valve 104 may be reversed.

[0199] The two-way valve 112 is a refrigerant flow path closing mechanism. The two-way valve 112 functions as a third refrigerant flow path control mechanism that switches the direction of the refrigerant flow to either the direction of the refrigerant junction 113 (that is, the direction of the refrigerant flow path FP36) or the direction of the R evaporator 14a (that is, the direction of the refrigerant flow path FP38) by selectively opening and closing.

[0200] The refrigerator 1A is a structure in which a confluence portion 110 provided between the F capillary tube 53b and the F evaporator 14b is connected to the outflow port 101b of the three-way valve 101 by using the refrigerant flow path FP. In addition, the refrigerator 1A is a structure in which a branch portion 111 provided downstream of the F evaporator 14b is connected to the defrosting capillary tube 103 by using the refrigerant flow path FP. In addition, the refrigerator 1A is a structure in which a pipe on the refrigerant path connecting the R evaporator 14a to the compressor 24 and a pipe on the refrigerant path connecting the F evaporator 14b to the compressor 24 are joined (connected) at a refrigerant confluence portion 113. In addition, the refrigerator 1A is provided with a two-way valve 112 between the branch portion 111 and the refrigerant confluence portion 113. The two-way valve 112 is opened (opened) during freezing and cooling operation, and is closed (closed) during defrosting operation.

[0201] In the refrigerator 1A of the second embodiment, other parts are similar to the refrigerator 1 of the first embodiment ( Figure 5 )same.

[0202] In the second embodiment, the refrigerator 1A opens the outlet 101b side of the three-way valve 101 during the defrosting operation and closes the two-way valve 112. As a result, the high-temperature refrigerant from the compressor 24 directly flows through the F evaporator 14b to heat the F evaporator 14b. The refrigerant thereafter flows to the defrosting capillary tube 103 side because the two-way valve 112 side is closed, and absorbs heat in the R evaporator 14a.

[0203] The refrigerator 1A of the second embodiment is the same as the refrigerator 1 of the first embodiment. The high-temperature refrigerant from the compressor 24 heats the F evaporator 14b, and the R evaporator 14a absorbs heat during the heating, thereby achieving defrosting operation. The refrigerator 1A of the second embodiment is the same as the refrigerator 1 of the first embodiment. In the internal heat exchange section 58, the R capillary tube 53a, the F capillary tube 53b, and the defrosting capillary tube 103 exchange heat with the refrigerant flow path FP36. The state of the refrigeration cycle of the refrigerator 1A of the second embodiment is the same as Figure 7 as well as Fig.10 The state of the refrigeration cycle of the refrigerator 1 of the first embodiment shown is the same. Therefore, the refrigerator 1A of the second embodiment has the same effect as the refrigerator 1 of the first embodiment. Therefore, the effect of the refrigerator 1 of the first embodiment is not limited to the F evaporator 14b having the defrosting pipe 102, and the same effect can be achieved as long as the refrigerant ejected from the compressor 24 can be used to heat the F evaporator 14b.

[0204] Furthermore, when comparing the refrigerator 1 of the first embodiment with the refrigerator 1A of the second embodiment, the refrigerator 1 of the first embodiment is different from the refrigerator 1A of the second embodiment in that the two-way valve 112 is not used. In this respect, the refrigerator 1 of the first embodiment has the possibility of suppressing space and cost by an amount equivalent to that of not using the two-way valve 112, compared with the refrigerator 1A of the second embodiment.

[0205] In contrast, the refrigerator 1A of the second embodiment can use a general evaporator without the defrosting pipe 102 as the F evaporator 14b. Therefore, the refrigerator 1A of the second embodiment can reduce the cost of the F evaporator 14b accordingly, and can improve the versatility and design freedom of the F evaporator 14b.

[0206] As described above, the refrigerator 1A according to the second embodiment is different from the refrigerator 1 ( Figure 5 ) is the same as the conventional heating system, and can defrost in a shorter time and with higher heating efficiency.

[0207] Moreover, according to the refrigerator 1A of the second embodiment, the refrigerator 1 ( Figure 5 ) compared to the conventional evaporator 14a, since a general evaporator without the defrosting pipe 102 can be used as the F evaporator 14b, the cost of the F evaporator 14b can be reduced accordingly, and the versatility and design freedom of the F evaporator 14b can be improved.

[0208] The present invention is not limited to the above-mentioned embodiments, and includes various modifications. For example, the above-mentioned embodiments are described in detail to explain the present invention in an easy-to-understand manner, and are not necessarily limited to all the structures described. In addition, a part of the structure of the embodiment can be replaced with other structures, and other structures can also be added to the structure of the embodiment. In addition, for a part of each structure, other structures can be added, removed, or replaced.

[0209] For example, the pressure reducer of the refrigerator may be provided with an expansion valve (not shown) capable of pressure control instead of the capillary tube. Such a refrigerator can adjust the pressure of the refrigerant as necessary.

Claims

1. A refrigerator, characterized in that: have: Cold room; Freezer; a compressor, which compresses the refrigerant; a heat dissipation mechanism that dissipates heat from the refrigerant; a refrigeration evaporator for evaporating a refrigerant during a refrigeration cooling operation for cooling the refrigeration chamber; a freezing evaporator for evaporating a refrigerant during a freezing and cooling operation for cooling the freezing chamber; and The defrosting pipe is arranged inside or near the refrigerating evaporator and performs heat exchange with the refrigerating evaporator. The structure is such that, during the defrosting operation, the refrigerant ejected from the compressor flows in the order of the defrosting pipe, the refrigerating evaporator, and the compressor, thereby heating the freezing evaporator to remove frost attached to the freezing evaporator. The flow resistance of the refrigerant path connecting the outlet of the defrosting pipe to the inlet of the refrigerating evaporator is set to be lower than the flow resistance of the refrigerant path connecting the outlet of the heat dissipation mechanism to the inlet of the refrigerating evaporator.

2. The refrigerator according to claim 1, characterized in that: Also available: a refrigerant flow path in which a refrigerant flows; A refrigeration pressure reducing mechanism that reduces the pressure of the refrigerant during refrigeration cooling; A refrigeration pressure reducing mechanism that reduces the pressure of the refrigerant during refrigeration cooling; a first refrigerant control mechanism that switches the direction of the refrigerant discharged from the heat dissipation mechanism to either the direction of the refrigeration pressure reducing mechanism or the direction of the freezing pressure reducing mechanism; as well as The second refrigerant control mechanism is provided between the compressor and the first refrigerant control mechanism, and switches the flow direction of the refrigerant ejected from the compressor to either the direction of the heat dissipation mechanism or the direction of the defrosting pipe. The refrigerant flow path is configured such that, during refrigeration and cooling operation, the refrigerant ejected from the compressor flows in the order of the second refrigerant control mechanism, the heat dissipation mechanism, the first refrigerant control mechanism, the refrigeration pressure reducing mechanism, the refrigeration evaporator, and the compressor. The refrigerant flow path is configured such that, during the refrigeration and cooling operation, the refrigerant ejected from the compressor flows in the order of the second refrigerant control mechanism, the heat dissipation mechanism, the first refrigerant control mechanism, the refrigeration pressure reducing mechanism, the refrigeration evaporator, and the compressor. The refrigerant flow path is configured such that, during a defrosting operation, the refrigerant discharged from the compressor flows in the order of the second refrigerant control mechanism, the defrosting pipe, the refrigeration evaporator, and the compressor.

3. The refrigerator according to claim 1, characterized in that: Also available: a merging portion that merges a pipe on a refrigerant path connecting the compressor to the refrigeration evaporator and a pipe on a refrigerant path connecting the defrosting pipe to the refrigeration evaporator; and A check valve is provided between the confluence portion and the defrosting pipe.

4. The refrigerator according to claim 1, characterized in that: The defrosting pipe is expanded so as to efficiently contact the fins provided in the refrigeration evaporator.

5. The refrigerator according to claim 2, characterized in that: The defrosting pressure reducing mechanism is provided between the defrosting pipe and the refrigerating evaporator and reduces the pressure of the refrigerant during the defrosting operation. The flow path resistance of the defrosting pressure reducing mechanism is set to be lower than the flow path resistance of the refrigerating pressure reducing mechanism.

6. The refrigerator according to claim 1, characterized in that: A heat exchange unit is further provided for performing heat exchange between a refrigerant flow path from the outlet of the defrosting pipe to the inlet of the refrigerating evaporator and a refrigerant flow path from the refrigerating evaporator to the compressor during a defrosting operation.

7. A refrigerator, characterized in that: have: Cold room; Freezer; a compressor, which compresses the refrigerant; a refrigeration evaporator for evaporating a refrigerant during a refrigeration cooling operation for cooling the refrigeration chamber; a freezing evaporator for evaporating a refrigerant during a freezing and cooling operation for cooling the freezing chamber; a refrigerant flow path in which a refrigerant flows; A refrigeration pressure reducing mechanism that reduces the pressure of the refrigerant during refrigeration cooling operation; and A refrigeration decompression mechanism that reduces the pressure of the refrigerant during refrigeration and cooling operations. The refrigerant flow path is structured as follows: after the refrigerant ejected from the compressor exchanges heat with the freezing evaporator, it flows in the order of the refrigerating evaporator and the compressor, thereby removing frost attached to the freezing evaporator. During the defrosting operation, the refrigerant flows bypassing the refrigerating pressure reducing mechanism and part or all of the freezing pressure reducing mechanism.

8. The refrigerator according to claim 7, characterized in that: Also available: a defrosting pressure reducing mechanism that reduces the pressure of the refrigerant during a defrosting operation; and a merging portion that merges a pipe on a refrigerant path connecting the compressor to the refrigerating evaporator in a cooling operation with a pipe on a refrigerant path connecting the compressor to the refrigerating evaporator in a defrosting operation, The defrosting pressure reducing mechanism is provided in the flow path from the refrigerant after heat exchange with the freezing evaporator in the defrosting operation to the confluence portion, and The refrigeration pressure reducing mechanism is provided between the compressor and the confluence portion on the refrigerant path connecting the compressor to the refrigeration evaporator during cooling operation. The flow path resistance of the defrosting pressure reducing mechanism is set to be lower than the flow path resistance of the refrigerating pressure reducing mechanism.

9. A refrigerator, characterized in that: have: Cold room; Freezer; a compressor, which compresses the refrigerant; a heat dissipation mechanism that dissipates heat from the refrigerant; a refrigeration evaporator for evaporating a refrigerant during a refrigeration cooling operation for cooling the refrigeration chamber; a freezing evaporator for evaporating a refrigerant during a freezing and cooling operation for cooling the freezing chamber; A refrigeration pressure reducing mechanism that reduces the pressure of the refrigerant during refrigeration cooling; A refrigeration pressure reducing mechanism that reduces the pressure of the refrigerant during refrigeration cooling; a defrosting pressure reducing mechanism for reducing the pressure of the refrigerant during a defrosting operation for removing frost adhering to the refrigeration evaporator; a first refrigerant control mechanism that switches the direction of the refrigerant discharged from the heat dissipation mechanism to either the direction of the refrigeration pressure reducing mechanism or the direction of the freezing pressure reducing mechanism; A second refrigerant control mechanism, which is disposed between the compressor and the first refrigerant control mechanism and switches the direction of the refrigerant discharged from the compressor to either the direction of the heat dissipation mechanism or the direction of the refrigeration evaporator; as well as A refrigerant path causes the refrigerant discharged from the compressor to flow in the order of the evaporator for freezing, the decompression mechanism for defrosting, the evaporator for refrigeration, and the compressor during the defrosting operation.

10. The refrigerator according to claim 9, characterized in that: Also available: a refrigerant converging portion that merges a pipe on a refrigerant path connecting the refrigerating evaporator to the compressor with a pipe on a refrigerant path connecting the freezing evaporator to the compressor; as well as The third refrigerant flow control mechanism is disposed between the freezing evaporator and the refrigerant junction, and switches the direction of the refrigerant flow to either the direction of the refrigerant junction or the direction of the refrigerating evaporator.

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