refrigerator

Abstract

A refrigerator includes a cooling circuit, wherein the cooling circuit has a first flow path for circulating refrigerant, which is connected in the order of a compressor, a condenser, a capillary tube, and an evaporator. The cooling circuit also includes: a hot gas bypass pipe, which is configured to constitute a second flow path, and the second flow path allows the refrigerant compressed by the compressor to flow from the downstream of the compressor to the upstream of the evaporator; and an opening and closing unit, which opens or closes the hot gas bypass pipe, and the opening and closing unit can allow the refrigerant discharged from the compressor to flow into the first flow path or the second flow path, and the end of the downstream side of the hot gas bypass pipe is configured to be connected to the upper side in the vertical direction relative to the first pipe, and the first pipe connects the capillary tube downstream and the evaporator upstream.

Description

Technical Field

[0001] The present invention relates to a refrigerator, in particular to a refrigerator which removes frost attached to an evaporator by using hot air. Background Art

[0002] The evaporator, part of a refrigerator's cooling circuit, can become frost-prone due to the cooling of surrounding water vapor, reducing cooling performance. To address this issue, a hot gas defrosting method is known. A hot gas bypass pipe, connected to the upstream side of the evaporator, is provided downstream of the compressor, part of the cooling circuit. High-temperature gas is temporarily passed through the hot gas bypass pipe to the evaporator, thereby heating the evaporator and defrosting it (e.g., Patent Document 1).

[0003] [Prior art literature]

[0004] [Patent Document]

[0005] [Patent Document 1]: Japanese Patent Application Publication No. 2018-54287

[0006] However, in refrigerators including a hot gas bypass pipe, such as that disclosed in Patent Document 1, refrigerant flowing within the cooling circuit may sometimes flow into the hot gas bypass pipe during normal operation (i.e., when the hot gas bypass pipe is not in use). Therefore, if refrigerant flows into the hot gas bypass pipe during normal operation, the effective refrigerant flow rate within the cooling circuit may decrease, thereby reducing cooling efficiency.

[0007] In view of this, it is necessary to improve the existing refrigerator to solve the above problems. Summary of the Invention

[0008] An object of the present invention is to provide a refrigerator that can prevent a reduction in cooling efficiency due to a refrigerant flowing into a hot gas bypass pipe.

[0009] To achieve the above object, the present invention provides a refrigerator comprising: a cooling circuit having a first flow path for circulating a refrigerant connected in order of a compressor, a condenser, a capillary tube, and an evaporator, wherein the compressor compresses the refrigerant sent from the evaporator, the condenser condenses the refrigerant sent from the compressor, the capillary tube expands the refrigerant sent from the condenser, and the evaporator evaporates the refrigerant sent from the capillary tube.

[0010] The cooling circuit further comprises:

[0011] a hot gas bypass pipe configured to constitute a second flow path that allows the refrigerant compressed by the compressor to flow from downstream of the compressor to upstream of the evaporator; and

[0012] an opening and closing unit, the opening and closing unit opening or closing the hot gas bypass pipe,

[0013] The opening and closing unit can allow the refrigerant discharged from the compressor to flow into the first flow path or the second flow path.

[0014] The downstream end portion of the hot gas bypass pipe is provided to be connected vertically above a first pipe connecting the capillary tube at the downstream side and the evaporator at the upstream side.

[0015] In this way, in a refrigerator that defrosts the evaporator using hot gas defrosting, refrigerant can be prevented from flowing into the hot gas bypass pipe during normal refrigerator operation, and the refrigerant flows from the capillary tube to the evaporator. This prevents a decrease in the amount of refrigerant effectively used within the cooling circuit, thereby preventing a decrease in cooling efficiency and an increase in power consumption.

[0016] Furthermore, the hot gas bypass pipe has at least one refrigerant backflow prevention portion, and the refrigerant backflow prevention portion is formed into a U-shaped structure that first rises and then falls in the vertical direction and opens downward.

[0017] Even if refrigerant flows into the hot gas bypass pipe, the presence of a vertically height-differenced portion prevents refrigerant from flowing upstream through the refrigerant backflow prevention portion. This prevents the amount of refrigerant effectively used within the cooling circuit from decreasing beyond a predetermined amount, thereby preventing a decrease in cooling efficiency and an increase in power consumption.

[0018] Furthermore, the hot gas bypass pipe has an inclined portion, and the arrangement of the inclined portion enables the height position of the hot gas bypass pipe in the vertical direction to change as its position in the horizontal direction changes.

[0019] When refrigerant flows into the hot gas bypass pipe, it must move against gravity. This prevents refrigerant from flowing into the hot gas bypass pipe and allows it to flow from the capillary tube to the evaporator. This reduces the amount of refrigerant effectively used within the cooling circuit, preventing a decrease in cooling efficiency and suppressing an increase in power consumption.

[0020] Furthermore, the inclined portion is provided so as to extend obliquely so that the upstream side of the flow path is vertically positioned higher than the downstream side.

[0021] Furthermore, the cooling circuit further includes a second pipeline, the second pipeline connecting the suction pipe and the hot gas bypass pipe, and the suction pipe connecting the evaporator and the compressor.

[0022] This allows the refrigerant to gradually return to the cooling circuit used during normal operation, where it flows into the hot gas bypass pipe, via the second pipe. This prevents a decrease in the amount of refrigerant effectively used within the cooling circuit, even if a predetermined amount or more of it flows into the hot gas bypass pipe. This prevents a decrease in cooling efficiency and an increase in power consumption.

[0023] Furthermore, the second pipeline is provided with a control valve, and the control valve is capable of adjusting the flow rate of the refrigerant passing through the second pipeline.

[0024] This allows for arbitrary adjustment of the flow rate of the fluid passing through the second pipe. This allows for control of the amount of refrigerant returned to the cooling circuit used during normal operation via the second pipe. Furthermore, during defrosting, hot gas can be prevented from flowing from the hot gas bypass pipe through the second pipe to the suction pipe, thereby preventing a decrease in defrosting efficiency and suppressing an increase in power consumption.

[0025] Furthermore, the opening of the control valve is controlled by a control device, and the control device controls the opening of the control valve by detecting whether the cooling circuit is in normal operation or defrosting action.

[0026] Furthermore, the control device detects the cooling efficiency according to the rotation speed of the compressor and the temperature sensed by the temperature sensor, and controls the opening of the control valve.

[0027] Furthermore, the cooling circuit also includes a connecting pipeline connecting the downstream compressor and the upstream condenser. In the cooling circuit, the opening and closing unit is a three-way valve arranged on the connecting pipeline and divides it into a first sub-pipeline and a second sub-pipeline. The upstream end of the hot gas bypass pipe is connected to the connecting pipeline, and the flow of refrigerant to the hot gas bypass pipe is controlled by the three-way valve.

[0028] Furthermore, the opening and closing unit is a two-way valve provided on the hot gas bypass pipe.

[0029] The refrigerator of the present invention has the following beneficial effects: The refrigerator of the present invention includes a compact damper that reduces airflow resistance. By disposing a plurality of baffles in the front-to-back and left-to-right directions, the airflow resistance in the damper is reduced. Furthermore, the airflow volume difference between the left and right airflow paths is reduced. Consequently, each storage compartment can be efficiently cooled to a predetermined temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a side sectional view of the refrigerator of the present invention.

[0031] Figure 2 It is a circuit diagram of the cooling circuit of the refrigerator of the present invention.

[0032] Figure 3 It is a schematic diagram of a part of the cooling circuit of the refrigerator of the present invention.

[0033] Figure 4 It is a schematic diagram of another part of the cooling circuit of the refrigerator of the present invention.

[0034] Figure 5 It is a schematic diagram of another part of the cooling circuit of the refrigerator of the present invention.

[0035] Figure 6 It is a schematic diagram of another part of the cooling circuit of the refrigerator of the present invention.

[0036] Figure 7 It is a schematic diagram of another part of the cooling circuit of the refrigerator of the present invention.

[0037] Figure 8 This is a circuit diagram of a cooling circuit in a second embodiment of the refrigerator according to the present invention.

[0038] Figure 9 It is a circuit diagram of a cooling circuit in a third embodiment of the refrigerator according to the present invention. DETAILED DESCRIPTION

[0039] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] Reference Figure 1 The refrigerator 1 of the present invention will be described. Figure 1 It is a side sectional view of the refrigerator. The refrigerator 1 has a refrigerator body 2, a door body 3 and a drawer 4. The door body 3 is rotatably arranged on the front side of the refrigerator body 2 when placed on a horizontal plane, and the drawer 4 is movable in the front-back direction. The door body 3 is connected to the refrigerator body 2 at its upper and lower parts by a hinge provided on at least one of its left and right sides, and rotates around the hinge axis of the hinge. As described above, the refrigerator 1 of the present invention includes two openable and closable components, namely the door body 3 and the drawer 4, but the present invention is not limited thereto. For example, it may have more drawers, or all opening and closing components may be composed of the door body.

[0041] In addition, the refrigerator 1 has: an outer shell 5 constituting the exterior of the refrigerator body 2, and an upper liner 6 and a lower liner 7 constituting the internal storage chamber. In the refrigerator 1 of the invention, the upper liner 6 forms a refrigeration chamber and the lower liner 7 forms a freezer chamber. When the door 3 is opened, the upper liner 6 can be accessed, and when the drawer 4 is opened, the lower liner 7 can be accessed. A storage box (not shown) is installed in the drawer 4, and the storage box moves as a whole with the drawer 4. The storage box is provided with an opening at the top, and when the user stores in the lower liner 7, the storage box is configured and stored through the opening. A foam insulation material 8 is filled between the outer shell 5 and each liner 6, 7 to insulate each liner 6, 7 from the outside of the refrigerator body 2. In addition, a foam insulation material 8 is also filled between the upper liner 6 and the lower liner 7.

[0042] like Figure 1 As shown, a cooling chamber 9 is formed at the rear of the lower inner container 7. An evaporator 24 serving as a cooling device is provided in the cooling chamber 9. As will be described later, the evaporator 24 forms part of the refrigerator's cooling circuit 20a. A fan 10 is provided in the cooling chamber 9, which blows the cool air generated by the evaporator 24 through an air duct 11 into each inner container 6, 7.

[0043] The air duct 11 is arranged at the rear part of each inner liner 6, 7, and the cold air generated by the cooling chamber 9 is guided to the front of each inner liner 6, 7 via the vent provided on the front surface of the air duct 11. A damper 12 is provided in the air duct 11, and the damper 12 is configured to be controlled to be opened or closed by a control device (not shown). The control device senses the temperature inside the refrigerator through a temperature sensor (not shown) provided in the upper inner liner 6, and controls the opening or closing of the damper 12 based on the temperature. In this way, the flow rate of the cold air flowing to the upper inner liner 6 (serving as a refrigerating chamber) can be adjusted, so that the internal temperature of the upper inner liner 6 is maintained constant within a temperature range different from the internal temperature of the lower inner liner 7 (serving as a freezing chamber).

[0044] A machine room 13 is formed at the rear and lower portion of the refrigerator body 2 and is provided with an evaporation dish (not shown) and the like for accumulating and evaporating drainage generated by defrosting the compressor 21 and the evaporator 24 .

[0045] Figure 2 This is the cooling circuit 20a of the refrigerator 1 of the present invention. The cooling circuit 20a includes a compressor 21, a condenser 22, a capillary tube 23, and an evaporator 24. As described later, the components of the cooling circuit 20a are fluidically connected by pipes in the aforementioned order, thereby forming a first flow path for the refrigerant to circulate within the cooling circuit 20a. Figure 2The arrows shown indicate the direction of refrigerant flow. That is, in the cooling circuit 20a, for example, in the relationship between the compressor 21 and the evaporator 24 described later, the refrigerant flows from the evaporator 24 on the upstream side of the flow path to the compressor 21 on the downstream side of the flow path via the suction pipe 28.

[0046] The compressor 21 compresses the gaseous refrigerant, bringing it to a high-temperature, high-pressure state. The compressed refrigerant is delivered to the condenser 22 via a connecting pipe 25. The connecting pipe 25 is equipped with a three-way valve 31, dividing it into a first sub-pipeline 25a and a second sub-pipeline 25b. The compressor 21 includes an inverter that adjusts the amount of refrigerant discharged per unit time by varying its rotational speed, thereby controlling the cooling capacity of the cooling circuit 20a. The condenser 22 dissipates heat from the refrigerant compressed by the compressor 21, condensing the refrigerant. The condensed refrigerant is delivered to the capillary tube 23 via a pipe 26.

[0047] The capillary tube 23 reduces the pressure of the refrigerant condensed by the condenser 22 to expand it, and the temperature decreases accordingly. The expanded refrigerant is sent to the evaporator 24 through the pipe 27. The evaporator 24 causes the refrigerant, which has been decompressed by the capillary tube 23, to evaporate and absorb heat. The evaporated refrigerant in a gaseous state is sent to the compressor 21 through the suction pipe 28 and compressed again. In this way, the cooling circuit 20a operates. In this embodiment, the capillary tube 23 is connected to the condenser 22 and the evaporator 24 via the pipe 26 and the pipe 27, but the capillary tube 23 may also include the pipes 26 and 27.

[0048] The suction pipe 28 is at least partially disposed close to the capillary tube 23 to enable heat exchange with the capillary tube 23 . The suction pipe 28 allows the refrigerant to flow from the evaporator 24 to the compressor 21 . Figure 2 The area 29 surrounded by the dotted line in FIG. 1 schematically shows the heat exchange portion.

[0049] When the evaporator 24 operates to cool the interior of the refrigerator 1, the surrounding water vapor may form frost. To defrost the evaporator 24, the refrigerator 1 of the present invention employs a hot gas defrost method, using hot gas compressed by the compressor 21 as the refrigerant. Therefore, the cooling circuit 20a includes a hot gas bypass pipe 30 connected to a connecting pipe 25, which connects the compressor 21 downstream and the condenser 22 upstream. A three-way valve 31 is provided in this connecting pipe. This valve can be altered to direct the refrigerant delivered from the compressor 21 via the first sub-pipeline 25a toward either the condenser 22 (i.e., the second sub-pipeline 25b) or the hot gas bypass pipe 30. This allows control over whether the refrigerant flows to the condenser 22 to cool the evaporator 24 or to the hot gas bypass pipe 30 to defrost the evaporator 24. The hot gas bypass pipe 30 is connected to a pipe connecting the capillary tube 23 downstream and the evaporator 24 upstream.

[0050] The hot gas bypass pipe 30 forms a second flow path for refrigerant to flow through the compressor 21, connecting pipe 25, hot gas bypass pipe 30, pipe 27, and evaporator 24. This second flow path is different from the refrigerant's flow through the first flow path, which is the compressor 21, connecting pipe 25, condenser 23, pipe 26, capillary tube 23, pipe 27, and evaporator 24. In this embodiment, the upstream end of the hot gas bypass pipe 30 is connected to the connecting pipe 25, but this structure is not limited to this. For example, the upstream end of the hot gas bypass pipe 30 may also be connected to pipe 26, which connects the downstream side of the condenser 22 and the upstream side of the capillary tube 23.

[0051] The three-way valve 31 is connected to a control device (not shown). The control device controls the three-way valve 31 so that the refrigerant flows to the condenser 22 (i.e., the second sub-pipeline 25b) during normal operation, which will be described later, and flows to the hot gas bypass pipe 30 during defrosting, which will be described later. The refrigerant is discharged from the compressor 21 via the first sub-pipeline 25a.

[0052] In this specification, the state in which the refrigerator 1 is normally operated (i.e., the state in which the refrigerator 1 is operated to cool the interior of the refrigerator or maintain the temperature thereof) is appropriately referred to as "normal operation." Furthermore, the state in which the refrigerator 1 is operated to defrost the evaporator 24 (i.e., the state in which the refrigerator 1 is operated to open the three-way valve 31 so that the refrigerant flows from the three-way valve 31 to the hot gas bypass pipe 30, thereby allowing hot gas to flow to the evaporator 24) is appropriately referred to as "defrost operation."

[0053] Figure 3 Schematic diagram of the configuration method of the hot gas bypass pipe 30 of the present invention. Figure 3As shown, the capillary tube 23 is connected to the evaporator 24 via a pipe 27. In addition, the pipe 27 is connected to the hot gas bypass pipe 30 on the upstream side of the connection portion with the evaporator 24. Figure 3 In the embodiment, a through-portion 32 is provided upstream of the pipe 27 (or capillary tube 23) and the hot gas bypass pipe 30. The through-portion 32 is a portion of the lower inner liner 7 that connects the cooling chamber 9 to the side of the lower inner liner 7 where the foam insulation material 8 is located. The pipe 27 (or capillary tube 23) and the hot gas bypass pipe 30 are provided so as to pass through the lower inner liner 7 via the through-portion 32.

[0054] When the refrigerator is in normal operation, the hot gas bypass pipe 30 is not used. However, during this normal operation, at least a portion of the refrigerant becomes liquid in the flow path from the condenser 22 to the evaporator 24, and the liquid refrigerant flowing from the capillary tube 23 to the evaporator 24 may flow in the direction opposite to the direction in which the refrigerant normally flows toward the hot gas bypass pipe 30.

[0055] The refrigerant in the cooling circuit 20a is injected in a predetermined amount to achieve a predetermined cooling performance. Therefore, when refrigerant flows back into the hot gas bypass pipe 30, the amount of refrigerant effectively usable by the cooling circuit 20a during normal operation may decrease, potentially failing to achieve the predetermined cooling performance. Furthermore, due to the reduced cooling performance, the cooling circuit 20a may operate at an increased rate to cool the evaporator 24 (e.g., by increasing the amount of refrigerant discharged from the compressor 21), potentially increasing power consumption.

[0056] Therefore, the hot gas bypass pipe 30 of the refrigerator 1 of the present invention has a connecting portion 30a, such as Figure 3 As shown, the connection portion 30a is configured so that the hot gas bypass pipe 30 is connected to the pipe 27 (or capillary tube 23) (hereinafter, appropriately referred to as the first pipe) from the vertical upper side. Point A represents the junction between the hot gas bypass pipe 30 and the first pipe 27. Since the refrigerant flowing in the first pipe 27 (which is downstream of the capillary tube 23) is essentially in a liquid state, it tends to flow vertically downward due to gravity. Therefore, by connecting the pipes from the vertical upper side, as in the connection portion 30a of the hot gas bypass pipe 30 of this embodiment, it is possible to suppress the flow of refrigerant into the hot gas bypass pipe 30.

[0057] In addition, if Figure 3As shown, a refrigerant backflow prevention portion 30b may be further provided in the hot gas bypass pipe 30. The refrigerant backflow prevention portion 30b is provided in a portion of the hot gas bypass pipe 30, with the upstream side standing substantially perpendicularly relative to the downstream side. As a result, the upstream side of the hot gas bypass pipe 30 is vertically positioned above the downstream side, and further upstream of this portion, the refrigerant backflow prevention portion 30b descends vertically downward.

[0058] By providing a generally U-shaped structure that first rises and then falls in the vertical direction and opens downward, even if liquid refrigerant flows into the hot gas bypass pipe 30, it is difficult for the refrigerant to flow over the raised portion downstream of the refrigerant backflow prevention portion 30b and flow into the upstream side of the hot gas bypass pipe 30. Therefore, it is possible to suppress the refrigerant from flowing into the upstream side of the refrigerant backflow prevention portion 30b, thereby controlling the amount of refrigerant flowing into the hot gas bypass pipe 30 to below a certain level.

[0059] This prevents a decrease in the cooling performance of the cooling circuit 20a and an increase in power consumption. Furthermore, the total amount of refrigerant filled in the cooling circuit 20a and the cooling control can be designed by taking into account the amount of refrigerant reduction (i.e., the amount by which the refrigerant volume may decrease from point A to the refrigerant backflow prevention portion 30b).

[0060] The refrigerant backflow prevention portion 30 b can be provided at a location behind the lower inner liner 7 that is thermally insulated from the outside air by the foam insulation material 8 or the like.

[0061] Figure 4 This diagram shows an embodiment in which a refrigerant backflow prevention portion 30b is provided at this location, and is a schematic diagram showing the lower inner tank 7 from the back. Figure 5 yes Figure 4 The circle B in FIG3 is enlarged in a perspective view. The refrigerant backflow prevention portion 30 b may be provided in the cooling chamber 9 including the evaporator 24 , which is located further downstream in the flow path of the hot gas bypass pipe 30 . Figure 6 An embodiment in which a refrigerant backflow prevention portion 30 b is provided in the cooling chamber 9 is shown, and the evaporator 24 , pipes 27 (or capillary tubes 23 ) and 28 connected to the evaporator 24 , and a hot gas bypass pipe 30 are illustrated.

[0062] In the above embodiment, the refrigerant backflow prevention portion 30b is formed substantially vertically on both its upstream and downstream sides. However, this configuration is not required. It is sufficient to have a configuration that creates a vertical height difference in the hot gas bypass pipe 30 relative to the vertical position of the hot gas bypass pipe 30 on the point A side, with the upstream side being higher. Therefore, for example, the connection between the refrigerant backflow prevention portion 30b and other portions of the hot gas bypass pipe 30 may be formed at either an acute angle or an obtuse angle, such as in the Greek letter Ω. Furthermore, the pipe does not need to be a straight line; it may also be formed in an irregular curve.

[0063] In addition, if Figure 3 As shown, the hot gas bypass pipe 30 may also include an inclined portion 30c, which is configured to extend at an angle such that the upstream side of the flow path is vertically higher than the downstream side. In other words, the vertical height of the hot gas bypass pipe 30 may change as its horizontal position changes. This allows the refrigerant to flow into the hot gas bypass pipe 30 against gravity, thus controlling the flow of refrigerant into the hot gas bypass pipe 30.

[0064] Figure 7 yes Figure 3 Another example of the embodiment shown. Figure 3 In the embodiment shown, a generally U-shaped structure that is open to the bottom in the vertical direction is provided downstream of the capillary tube 23 or downstream of the pipe 27. The downstream of the generally U-shaped structure is connected to the evaporator. In addition, a hot gas bypass pipe 30 is connected to the upper part of the U-shaped structure in the vertical direction. Figure 7 In the embodiment shown, no substantially U-shaped structure is provided downstream of the pipe 27 (or capillary tube 23). Similarly, the pipe to which the hot gas bypass pipe 30 is connected may have any shape.

[0065] Figure 8 This is a circuit diagram of the cooling circuit 20b of the refrigerator 1 according to another embodiment. Compared to the cooling circuit 20a, the cooling circuit 20b further includes a refrigerant return pipe 33 (hereinafter also referred to as a second pipe). The second pipe 33 connects the hot gas bypass pipe 30 and the suction pipe 28. By using a pipe having an inner diameter smaller than that of the hot gas bypass pipe 30 and the suction pipe 28 for the second pipe 33, the refrigerant flowing into the hot gas bypass pipe 30 can be gradually returned to the suction pipe 28 side. Thus, even if the refrigerant flows into the hot gas bypass pipe 30, it is possible to prevent the refrigerant from accumulating in the hot gas bypass pipe 30 in an amount exceeding a certain level, or to suppress an increase in the amount of accumulated refrigerant.

[0066] A control valve 34 can be provided in the second pipeline 33, and the control valve 34 can control the flow rate of the refrigerant and the like flowing through the pipeline. The opening of the control valve 34 is controlled by a control device (not shown). The control device controls the opening by detecting whether the cooling circuits 20a, 20b are in normal operation or in a defrosting operation. In addition, the cooling efficiency can also be detected based on the rotation speed of the compressor 21 and the temperature sensed by the temperature sensor (which is arranged in the refrigerator), thereby controlling the opening of the control valve 34. Thus, during normal operation, the flow rate of the refrigerant returning to the suction pipe 28 side can be adjusted. In addition, during the defrosting operation, the control valve 34 can be closed so that the hot gas flowing through the hot gas bypass pipe 30 does not pass through the second pipeline 33, thereby preventing the defrosting efficiency from being reduced.

[0067] In the cooling circuits 20a and 20b of the refrigerator 1 in the above embodiment, the three-way valve 31 is used to control the flow of the refrigerant to the hot gas bypass pipe 30, but the invention is not limited thereto and any other opening and closing method can be used to achieve this. Figure 9 As shown in the cooling circuit 20c, a two-way valve 35 can be used instead of the three-way valve 31. In the present invention, the two-way valve 35 and the three-way valve 31 can be collectively referred to as an opening and closing unit. Figure 9 The circuit diagram of the cooling circuit 20c is shown. Figure 8 A modification of the cooling circuit 20b of the refrigerator 1 according to the embodiment of FIG. In the cooling circuit 20c, the hot gas bypass pipe 30 is connected to the connecting pipe 25 without using a three-way valve. Furthermore, a two-way valve 35 is provided on the hot gas bypass pipe 30, and the two-way valve 35 is electrically connected to a control device. The control device can switch the two-way valve 35 open or closed, thereby controlling the flow of refrigerant into the hot gas bypass pipe 30. Of course, in the cooling circuit 20a, a two-way valve 35 can also be provided instead of the three-way valve 31, as described above.

[0068] In the cooling circuit 20c, as Figure 9 As shown, even if the two-way valve 35 is opened, switching the refrigerant flow to the hot gas bypass pipe 30, the refrigerant can still flow to the condenser 22 and capillary tube 23. Therefore, the defrosting efficiency of cooling circuit 20c may be lower than that of cooling circuit 20b. Therefore, by providing another two-way valve 35 in the second sub-pipeline 25b or the pipe 26, it is possible to configure the refrigerant to flow only to the hot gas bypass pipe 30 during the defrosting operation.

[0069] As described above, according to the present invention, a refrigerator can be provided that can avoid a decrease in cooling efficiency due to the refrigerant flowing into the hot gas bypass pipe 30 , and therefore can be preferably used in the industrial field of such refrigerators.

[0070] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A refrigerator, characterized in that: The cooling circuit includes a first flow path for circulating a refrigerant, the first flow path being connected in this order to a compressor, a condenser, a capillary tube, and an evaporator, wherein the compressor compresses the refrigerant sent from the evaporator, the condenser condenses the refrigerant sent from the compressor, the capillary tube expands the refrigerant sent from the condenser, and the evaporator evaporates the refrigerant sent from the capillary tube. The cooling circuit further comprises: a hot gas bypass pipe configured to constitute a second flow path that allows the refrigerant compressed by the compressor to flow from downstream of the compressor to upstream of the evaporator; and an opening and closing unit, the opening and closing unit opening or closing the hot gas bypass pipe, The opening and closing unit can allow the refrigerant discharged from the compressor to flow into the first flow path or the second flow path. The downstream end portion of the hot gas bypass pipe is provided to be connected vertically above a first pipe connecting a downstream portion of the capillary tube and an upstream portion of the evaporator.

2. The refrigerator according to claim 1, wherein: The hot gas bypass pipe has at least one refrigerant backflow prevention portion, and the refrigerant backflow prevention portion is formed in a U-shaped structure that first rises and then falls in a vertical direction and is open downward.

3. The refrigerator according to claim 2, characterized in that The hot gas bypass pipe has an inclined portion. The arrangement of the inclined portion causes the height position of the hot gas bypass pipe in the vertical direction to change as its position in the horizontal direction changes.

4. The refrigerator according to claim 3, characterized in that The inclined portion is provided so as to extend obliquely so that the upstream side of the flow path is vertically positioned higher than the downstream side.

5. The refrigerator according to any one of claims 1 to 4, characterized in that The cooling circuit further includes a second pipeline connecting a suction pipe and the hot gas bypass pipe, and the suction pipe connects the evaporator and the compressor.

6. The refrigerator according to claim 5, characterized in that The second pipeline is provided with a control valve, and the control valve is capable of adjusting the flow rate of the refrigerant passing through the second pipeline.

7. The refrigerator according to claim 6, characterized in that The opening degree of the control valve is controlled by a control device, and the control device controls the opening degree of the control valve by detecting whether the cooling circuit is in normal operation or defrosting action.

8. The refrigerator according to claim 6, wherein: The control device detects the cooling efficiency according to the rotation speed of the compressor and the temperature sensed by the temperature sensor, and controls the opening of the control valve.

9. The refrigerator according to claim 5, characterized in that The cooling circuit also includes a connecting pipeline connecting the downstream compressor and the upstream condenser. In the cooling circuit, the opening and closing unit is a three-way valve arranged on the connecting pipeline and divides it into a first sub-pipeline and a second sub-pipeline. The upstream end of the hot gas bypass pipe is connected to the connecting pipeline, and the flow of refrigerant to the hot gas bypass pipe is controlled by the three-way valve.

10. The refrigerator according to claim 5, characterized in that The opening and closing unit is a two-way valve provided on the hot gas bypass pipe.

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