refrigerator

Abstract

To provide a refrigerator capable of efficiently performing a defrosting process in a short time by using a hog gas-like refrigerant.SOLUTION: A refrigerator includes: a refrigerating chamber 7; a cooling circuit in which a cooling cycle for making a refrigerant successively flow to a compressor 21, a condenser, and evaporator 24 and then return to the compressor 21 is performed; a hot gas bypass pipe directly connecting an outlet side of the compressor 21 and an inlet side of the evaporator 24; and a fan 12 for circulating a gas inside of the refrigerator. The gas is circulated by the fan 12 so that the gas passing through the evaporator 24 from a lower side to an upper side is made to flow into the refrigerating chamber 7, and the gas flowing in the refrigerating chamber 7 returns to a lower side of the evaporator 24 again. An inlet and an outlet of a heat exchange pipe of the evaporator 24 in which the refrigerant flows, are disposed at an upper side of the evaporator 24, and a first defrosting process is executed to perform a gas defrosting process for supplying the gas flowing in the refrigerating chamber 7 to a lower side of the evaporator 24, with a hot gas defrosting process for supplying the refrigerant discharged from the compressor 21 to the inlet of the heat exchange pipe via the hot gas bypass pipe.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a refrigerator, and more particularly to a refrigerator that removes frost adhering to an evaporator by using a hot gaseous refrigerant. [Background technology]

[0002] The evaporator, which constitutes a part of the cooling circuit of a refrigerator, may become frosted as the surrounding water vapor is cooled, and the cooling performance may be reduced. To address this, a hot gas defrosting process is known in which a hot gas bypass pipe connected to the upstream side of the evaporator is provided downstream of the compressor, which constitutes a part of the cooling circuit, and high-temperature gas is temporarily flowed through the hot gas bypass pipe to heat the evaporator and perform defrosting (see, for example, Patent Document 1). In Patent Document 1, the evaporator is heated and defrosted by directly supplying the hot gas refrigerant discharged from the compressor to the inlet of the heat exchange pipe of the evaporator. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-54287 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the hot gas defrosting process described in Patent Document 1, the temperature difference between the hot gas refrigerant being supplied and the heat exchange pipe is large, so that the refrigerant condenses in the heat exchange pipe. The heat exchange pipe of the evaporator usually extends from the upper inlet of the evaporator to the lower side while meandering from side to side, and then returns to the upper side to reach the outlet. Therefore, the condensed refrigerant accumulates on the lower side of the evaporator, and the temperature rise on the outlet side of the heat exchange pipe slows down, so that the defrosting process may take a long time.

[0005] SUMMARY OF THE PRESENT DISCLOSURE In view of the above, an object of the present invention is to provide a refrigerator capable of efficiently performing defrosting processing of an evaporator in a short time by using a hot gaseous refrigerant. [Means for solving the problem]

[0006] The refrigerator according to the present invention comprises: A refrigerator compartment, a cooling circuit in which a cooling cycle is implemented in which a refrigerant flows through a compressor, a condenser, an evaporator, and then returns to the compressor; a hot gas bypass pipe that directly connects the outlet side of the compressor and the inlet side of the evaporator; A fan for circulating gas inside the cabinet; Equipped with The fan circulates the gas so that the gas that has passed through the evaporator flows from bottom to top into the refrigerator compartment, and the gas that has flowed through the refrigerator compartment returns to the lower side of the evaporator again. The inlet and the outlet of the heat exchange pipe of the evaporator through which the refrigerant flows are disposed above the evaporator, The present invention is characterized in that a first defrosting process is carried out, which performs a hot gas defrosting process in which the refrigerant discharged from the compressor is supplied to the inlet of the heat exchange pipe via the hot gas bypass pipe, and a gas defrosting process in which the gas that has flowed inside the refrigerator compartment is supplied to the lower side of the evaporator.

[0007] When hot gas defrosting is performed using a hot gas refrigerant, the refrigerant may condense and accumulate below the evaporator because the heat exchange pipe of the evaporator is at a low temperature. However, according to the present invention, by supplying gas that has been heated by flowing inside the refrigerator compartment to the lower side of the evaporator, the area below the evaporator is heated, and the condensation of the refrigerant is suppressed, and the refrigerant is prevented from accumulating below the evaporator. Therefore, a refrigerator can be provided that can perform the defrosting process of the evaporator efficiently in a short time using a hot gas refrigerant.

[0008] Further, the refrigerator according to the present invention comprises: When a predetermined time has elapsed or when the temperature of the gas flowing through the refrigerator compartment reaches a predetermined temperature after the first defrosting process is started, the gas defrosting process is stopped and a second defrosting process is carried out in which only the hot gas defrosting process is performed.

[0009] If the gas defrosting process using the gas flowing through the refrigerator compartment is continued, the temperature of the circulating gas may rise, causing a risk of an increase in the temperature inside the refrigerator compartment. According to the present invention, when a predetermined time has elapsed or when the temperature of the gas flowing through the refrigerator compartment reaches a predetermined temperature, the gas defrosting process is stopped and only the hot gas defrosting process is performed. This makes it possible to efficiently perform the defrosting process of the evaporator while suppressing the temperature rise in the refrigerator compartment.

[0010] Further, the refrigerator according to the present invention comprises: a switching valve that switches between an open state in which the refrigerant discharged from the compressor flows to the hot gas bypass pipe side to perform the hot gas defrosting process and a closed state in which the refrigerant discharged from the compressor flows to the condenser side to perform a normal operation; a refrigeration chamber damper that switches between an open state in which gas flows from a cooling flow passage in which the evaporator is disposed to the refrigeration chamber and a closed state in which gas does not flow from the cooling flow passage to the refrigeration chamber; A control unit that controls the compressor, the fan, the switching valve, and the refrigeration chamber damper; Further comprising: The control unit: The first defrosting process is started by opening the switching valve while the compressor is on and by opening the refrigerator compartment damper while the fan is on, and when a predetermined time has elapsed or when the temperature of the gas flowing through the refrigerator compartment has reached a predetermined temperature, at least the refrigerator compartment damper is closed, thereby switching from the first defrosting process to the second defrosting process.

[0011] According to the present invention, the control unit controls the compressor, the fan, the switching valve, and the refrigerator compartment damper, so that the first defrosting process and the second defrosting process can be performed reliably.

[0012] In addition, in the refrigerator according to the present invention, The control unit: The method is characterized in that the first defrosting process is switched to the second defrosting process based on timing data from a timer or measurement data from a temperature sensor placed inside the refrigerator compartment.

[0013] According to the present invention, it is possible to switch from the first defrosting process to the second defrosting process at an appropriate timing based on data from a timer or a temperature sensor.

[0014] Further, the refrigerator according to the present invention comprises: A freezer and a freezing chamber damper that switches between an open state in which gas flows from the cooling flow path to the freezing chamber and a closed state in which gas does not flow from the cooling flow path to the freezing chamber; Further comprising: The control unit: The freezer compartment damper is maintained in a closed state while the first defrosting process and the second defrosting process are performed.

[0015] According to the present invention, by controlling the freezer compartment damper to remain closed, it is possible to carry out the first defrosting process and the second defrosting process while reliably suppressing an increase in the temperature in the freezer compartment. Effect of the Invention

[0016] According to the present invention, it is possible to provide a refrigerator that can perform defrosting processing of an evaporator efficiently in a short time by using a hot gaseous refrigerant. [Brief description of the drawings]

[0017] [Figure 1] 1 is a side cross-sectional view illustrating a refrigerator according to an embodiment of the present invention. [Diagram 2] 1 is a diagram showing the configuration of a cooling circuit of a refrigerator according to one embodiment of the present invention. [Diagram 3]FIG. 1 is a diagram showing piping around an evaporator in a refrigerator according to one embodiment of the present invention. [Figure 4] FIG. 1 is a diagram illustrating a control system related to defrosting of a refrigerator according to one embodiment of the present invention. [Figure 5A] 5 is a time chart showing control when hot gas defrosting process and gas defrosting process are performed. [Figure 5B] 6 is a time chart showing control when only hot gas defrosting processing is performed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment for carrying out the present invention will be described with reference to the drawings. The refrigerator described below is intended to embody the technical idea of ​​the present invention, and the present invention is not limited to the following unless otherwise specified. In each drawing, the same reference numerals may be used for components having the same function. The size and positional relationship of components shown in each drawing may be exaggerated for clarity of explanation. The up and down direction in the drawings, except for the following description and line drawings, indicates the vertical direction in three-dimensional space.

[0019] Fig. 1 is a side cross-sectional view that typically shows a refrigerator 1 according to one embodiment of the present invention. First, an overview of the refrigerator 1 according to one embodiment of the present invention will be described with reference to Fig. 1.

[0020] The refrigerator 1 has a housing 2, and is provided with an upper door 3 and a lower door 4 rotatably attached to the front part of the housing 2 when placed on a horizontal floor. A freezer compartment 6 and a refrigerator compartment 7 are arranged inside the housing 2 (hereinafter referred to as the "interior"). A heat insulating material is arranged between the inner surface of the housing 2 and the outer surfaces of the freezer compartment 6 and the refrigerator compartment 7.

[0021] <Cooling channel> As shown in FIG. 1, a cooling flow path 10 is provided behind the freezer compartment 6 and the refrigerator compartment 7, and is composed of a lower cooling flow path 10A and an upper cooling flow path 10B separated by partition plates 11A and 11B, respectively. An evaporator 24 is provided in the cooling flow path 10 (more specifically, the lower cooling flow path 10A). As will be described later, the evaporator 24 constitutes a part of the cooling circuit 20 of the refrigerator 1. A fan 12 is provided above the evaporator 24 in the cooling flow path 10. The fan 12 can move the gas inside the compartment, and the gas that has passed through the evaporator 24 and been cooled can be supplied from the cooling flow path 10 to the freezer compartment 6 and the refrigerator compartment 7.

[0022] A freezer damper 13 is disposed in the upper opening of the lower partition plate 11A. When the freezer damper 13 is open, the gas that has passed through the evaporator 24 flows from the cooling flow path 10 (lower cooling flow path 10A) to the freezer chamber 6. On the other hand, when the freezer damper 13 is closed, the gas that has passed through the evaporator 24 does not flow from the cooling flow path 10 (lower cooling flow path 10A) to the freezer chamber 6. FIG. 1 shows the freezer damper 13 in a closed state.

[0023] When the fan 12 is operating and the freezer damper 13 is open, the gas that has flowed into the freezer chamber 6 from the cooling flow path 10 (lower cooling flow path 10A) circulates within the freezer chamber 6 and returns to the cooling flow path 10 (lower cooling flow path 10A) from the lower opening of the lower partition plate 11A. As a result, the gas passes through the evaporator 24 again and is cooled, repeating a similar flow cycle. As a result, the stored items in the freezer chamber 6 can be cooled.

[0024] However, the switching of whether or not to allow gas to flow into the freezer chamber 6 is not limited to the case where the freezer chamber damper 13 is used. For example, a movable fan cover that covers the outside of the fan 12 can also be used. When the fan cover is open, the gas discharged from the fan 12 flows into the freezer chamber 6, and when the fan cover is closed, the gas discharged from the fan 12 is prevented from flowing into the freezer chamber 6.

[0025] Furthermore, a refrigerator damper 14 is disposed between the lower cooling flow passage 10A and the upper cooling flow passage 10B. When the refrigerator damper 14 is open, the gas that has passed through the evaporator 24 flows from the lower cooling flow passage 10A to the upper cooling flow passage 10B. Furthermore, the gas that has flowed into the upper cooling flow passage 10B flows into the refrigerator chamber 7 from the cooling flow passage 10 (upper cooling flow passage 10B) through each opening provided at a plurality of height positions. On the other hand, when the refrigerator damper 14 is closed, the gas that has passed through the evaporator 24 does not flow from the lower cooling flow passage 10A to the upper cooling flow passage 10B. In FIG. 1, the refrigerator damper 14 is shown in an open state, and the flow of gas at that time is shown typically by dotted arrows.

[0026] When the fan 12 is operating and the refrigerator compartment damper 14 is open, the gas that has flowed into the refrigerator compartment 7 from the cooling flow path 10 (upper cooling flow path 10B) circulates inside the refrigerator compartment 7 and flows into the inlet 15A of the return flow path 15 that opens to the lower side of the refrigerator compartment 7. While the gas that has passed through the evaporator 24 circulates inside the refrigerator compartment 7, it can cool the items stored in the freezer compartment 6.

[0027] (return flow path) The return flow path 15 is a flow path that allows the gas circulated in the refrigerator compartment 7 to flow into the lower side of the cooling flow path 10 (lower cooling flow path 10A) without flowing into the freezer compartment 6. The return flow path 15 is arranged separated from the cooling flow path 10. The gas that flows into the refrigerator compartment 7 from the cooling flow path 10 (upper cooling flow path 10B) and circulates inside the refrigerator compartment 7 flows into the return flow path 15 from the inlet 15A. The gas flows through the return flow path 15 and flows into the lower side of the cooling flow path 10 (lower cooling flow path 10A) from the lower outlet 15B. That is, the gas flows into the lower side of the evaporator 24 arranged in the cooling flow path 10 (lower cooling flow path 10A). As a result, the gas passes through the evaporator 24 again and is cooled, and a similar flow cycle is repeated. As a result, the stored items in the refrigerator compartment 7 can be cooled.

[0028] A machine room 40 is disposed at the rear and bottom of the housing 2, in which a compressor 21, a condenser 22, an evaporation dish (not shown), and the like are disposed.

[0029] <Cooling circuit> 2 is a diagram showing a configuration of a cooling circuit 20 of a refrigerator 1 according to one embodiment of the present invention. Next, an overview of the cooling circuit 20 will be described with reference to FIG.

[0030] The cooling circuit 20 includes a compressor 21, a condenser 22, a capillary tube 23, and an evaporator 24. The components of the cooling circuit 20 are fluidly connected in the above order by piping, as described below, to form a first refrigerant flow path through which the refrigerant circulates within the cooling circuit 20. The arrows in FIG. 2 indicate the direction of the refrigerant flow.

[0031] The compressor 21 compresses the refrigerant in a gaseous state to a high temperature and high pressure state. The compressed refrigerant is sent to the condenser 22 through a pipe 25. The pipe 25 is provided with a switching valve (three-way valve) 31 as described below, and is divided into a pipe 25a and a pipe 25b. The compressor 21 is equipped with an inverter, and by changing the rotation speed, the amount of refrigerant discharged by the compressor per unit time can be adjusted, and the cooling capacity of the cooling circuit 20 can be controlled. The condenser 22 releases heat from the refrigerant compressed by the compressor 21 and condenses the refrigerant. The condensed refrigerant is sent to the capillary tube 23 through a pipe 26.

[0032] The capillary tube 23 reduces the pressure of the refrigerant condensed in the condenser 22, causing it to expand, and thus reducing the temperature. The expanded refrigerant is sent to the heat exchange pipe 24A of the evaporator 24 through the piping 27. In the heat exchange pipe 24A, where heat exchange is promoted by the fins, the refrigerant decompressed by the capillary tube 23 is evaporated and absorbs heat. The evaporated refrigerant in a gaseous state is sent to the compressor 21 through the suction pipe 28 and compressed again. In this manner, the cooling circuit 20 operates. In this embodiment, the capillary tube 23 is connected to the condenser 22 and the evaporator 24 through the piping 26 and the piping 27, but the capillary tube 23 may include the pipings 26 and 27.

[0033] The suction pipe 28, which carries the refrigerant from the evaporator 24 to the compressor 21, is disposed at least partially in close proximity to the capillary tube 23 so as to exchange heat with the capillary tube 23. In Fig. 2, an area 29 surrounded by a dotted line shows an outline of the heat exchange section.

[0034] When the evaporator 24 exchanges heat with the gas flowing inside the refrigerator 1, water vapor contained in the gas may frost. In order to defrost the evaporator 24, the refrigerator 1 according to this embodiment performs a hot gas defrosting process and a gas defrosting process, as described below. In the hot gas defrosting process, a hot gaseous refrigerant compressed by the compressor 21 is used. For this reason, the cooling circuit 20 includes a hot gas bypass pipe 30 connected to a pipe 25 connecting the downstream of the compressor 21 and the upstream of the condenser 22. A switching valve (three-way valve) 31 is provided at the connection portion, and the switching valve (three-way valve) 31 can change the refrigerant sent from the compressor 21 through the pipe 25a so as to flow to either the condenser 22 (i.e., the pipe 25b) or the hot gas bypass pipe 30. This makes it possible to control whether the refrigerant flows to the condenser 22 to cool the evaporator 24, or flows to the hot gas bypass pipe 30 to defrost the evaporator 24. The hot gas bypass pipe 30 is connected to a pipe that connects the downstream of the capillary tube 23 and the upstream of the evaporator 24 .

[0035] The hot gas bypass pipe 30 constitutes a second refrigerant flow path in which the refrigerant flows through the compressor 21-pipe 25-hot gas bypass pipe 30-pipe 27-evaporator 24, which is different from the first refrigerant flow path in which the refrigerant flows through the compressor 21-pipe 25-condenser 22-pipe 26-capillary tube 23-pipe 27-evaporator 24 in the above-mentioned cooling flow path. In this embodiment, the upstream end of the hot gas bypass pipe 30 is connected to the pipe 25, but the configuration is not limited to this. For example, the upstream end of the hot gas bypass pipe 30 may be connected to the pipe 26 that connects the downstream of the condenser 22 and the upstream of the capillary tube 23.

[0036] The switching valve (three-way valve) 31 is controlled to open and close by a control unit 100 (see FIG. 4). The control unit 100 controls the switching valve (three-way valve) 31 so that the refrigerant discharged from the compressor 21 via the pipe 25a flows to the condenser 22 (i.e., the pipe 25b) during normal operation, and to the hot gas bypass pipe 30 in a hot gas defrosting process described later.

[0037] In this specification, a state in which refrigerator 1 operates normally (i.e., a state in which refrigerator 1 operates to cool the inside of the refrigerator or to maintain the inside temperature) is appropriately referred to as a "normal operation." Also, a state in which refrigerator 1 operates to defrost evaporator 24 (i.e., a state in which refrigerator 1 operates to open switching valve (three-way valve) 31 so that refrigerant flows from switching valve (three-way valve) 31 to hot gas bypass pipe 30 and hot gas flows to evaporator 24) is appropriately referred to as a "hot gas defrosting process."

[0038] <Pipes around the evaporator> Fig. 3 is a diagram showing piping around the evaporator 24 in the refrigerator 1 according to one embodiment of the present invention. As shown in Fig. 3, the capillary tube 23 is connected to the inlet 24A1 of the heat exchange pipe 24A of the evaporator 24 via the piping 27. The outlet 24A2 of the heat exchange pipe 24A of the evaporator 24 is connected to the suction pipe 28. Both the inlet 24A1 and the outlet 24A2 of the heat exchange pipe 24A of the evaporator 24 are disposed on the upper side of the evaporator 24.

[0039] Furthermore, the pipe 27 is connected to a hot gas bypass pipe 30 upstream of the connection portion with the evaporator 24. In Fig. 3, a through-hole 32 is illustrated upstream of the pipe 27 (or the capillary tube 23) and the hot gas bypass pipe 30. The pipe 27 (or the capillary tube 23) and the hot gas bypass pipe 30 are disposed so as to penetrate a lower region of the housing 2 via the through-hole 32.

[0040] The hot gas bypass pipe 30 is not used when the refrigerator 1 is in normal operation. However, during the normal operation, at least a part of the refrigerant is in a liquid state in the cooling 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 into the hot gas bypass pipe 30 in a direction opposite to the direction in which the refrigerant normally flows.

[0041] A predetermined amount of refrigerant is injected into the cooling circuit 20 so as to satisfy a predetermined cooling performance. Therefore, if the refrigerant flows back into the hot gas bypass pipe 30, the amount of refrigerant that can be effectively used by the cooling circuit 20 during normal operation decreases, and the predetermined cooling performance may no longer be satisfied. In addition, a decrease in cooling performance may increase the proportion of the operation of the cooling circuit 20 to cool the evaporator 24, such as by increasing the amount of refrigerant discharged from the compressor 21, which may increase power consumption.

[0042] Therefore, as shown in FIG. 3, the hot gas bypass pipe 30 of the refrigerator 1 according to this embodiment has a connection part 30a configured so that the hot gas bypass pipe 30 is connected to the pipe 27 (or the capillary tube 23) (hereinafter, appropriately, referred to as the first pipe) from above in the vertical direction (up-down direction). Point A represents the connection point between the hot gas bypass pipe 30 and the first pipe 27. The refrigerant flowing in the first pipe 27 downstream of the capillary tube 23 basically flows in a liquid state, and therefore tends to flow vertically downward due to gravity. Therefore, by connecting the pipes from above in the vertical direction like the connection part 30a of the hot gas bypass pipe 30 according to this embodiment, it is possible to suppress the refrigerant from flowing into the hot gas bypass pipe 30.

[0043] 3, a refrigerant backflow prevention part 30b may be provided in the hot gas bypass pipe 30. The refrigerant backflow prevention part 30b is formed such that the upstream side of a part of the hot gas bypass pipe 30 rises substantially vertically relative to the downstream side, so that the upstream side of the hot gas bypass pipe 30 is positioned above the downstream side in the vertical direction, and the further upstream side of the part drops downward in the vertical direction.

[0044] By providing such a generally U-shaped pipe with an open bottom that rises and falls in the vertical position, even if liquid refrigerant flows into the hot gas bypass pipe 30, it becomes difficult for the refrigerant to flow beyond the rising portion downstream of the refrigerant backflow prevention unit 30b and further into the upstream side of the hot gas bypass pipe 30. Therefore, it is possible to suppress the refrigerant from flowing upstream of the refrigerant backflow prevention unit 30b, and it is possible to suppress the amount of refrigerant flowing into the hot gas bypass pipe 30 to a certain amount or less. Note that the inflow of refrigerant to the upstream side can also be suppressed by providing a check valve in the pipe 30c connected to the connection unit 30a of the hot gas bypass pipe 30, instead of the refrigerant backflow prevention unit 30b.

[0045] This makes it possible to suppress a decrease in the cooling performance of the cooling circuit 20 and an increase in power consumption. In addition, the total amount of refrigerant filled in the cooling circuit 20 and the cooling control can be designed taking into account the amount of refrigerant reduction (i.e., taking into account the possibility that the refrigerant will be reduced by the volume from point A to the refrigerant backflow prevention unit 30b described above).

[0046] The refrigerant backflow prevention unit 30b can be provided in a portion that is insulated from the outside air by a foam insulation material or the like, which is at the lower rear of the housing 2. However, the piping around the evaporator 24 is not limited to the above, and any other piping arrangement is also possible as long as at least the inlet 24A1 and the outlet 24A2 of the heat exchange pipe 24A of the evaporator 24 are disposed above the evaporator 24 and the hot gas bypass pipe 30 is communicated with the inlet 24A1 of the heat exchange pipe 24A.

[0047] (Hot gas defrosting) As described above, the hot gas defrosting process of the evaporator 24 can be performed by supplying the hot gas refrigerant discharged from the compressor 21 to the inlet 24A1 of the heat exchange pipe 24A of the evaporator 24 through the hot gas bypass pipe 31. The hot gas refrigerant flows through the heat exchange pipe 24A, which heats the pipe 24A and also heats the fins by thermal conduction. This melts the frost on the evaporator 24, and the melted liquid falls. The fallen liquid is received in a tray disposed below the evaporator 24 and flows into the evaporation tray in the machine room 40 via the drain pipe. The liquid that flows into the evaporation tray evaporates into the atmosphere.

[0048] As shown in Fig. 3, the heat exchange pipe 24A of the evaporator 24 extends downward from an inlet 24A1 located on the upper side of the evaporator 24 while meandering left and right, and then returns upward from the lowest point while meandering left and right again to reach an outlet 24A2 located on the upper side of the evaporator 24. In Fig. 3, the heat exchange pipe 24AA meandering back to the upper side is not shown. In other words, the inlet 24A1 and the outlet 24A2 of the heat exchange pipe 24A are both located on the upper side of the evaporator 24.

[0049] When only the hot gas defrosting process is performed, the temperature difference between the hot gaseous refrigerant and the heat exchange pipe 24A of the evaporator 24 is large, so the refrigerant condenses in the heat exchange pipe 24A and the condensed refrigerant accumulates below the evaporator 24. This slows down the temperature rise on the outlet side of the heat exchange pipe 24A, and there is a risk that the defrosting process will take a long time. Therefore, in the refrigerator 1 according to this embodiment, in addition to the hot gas defrosting process, the following gas defrosting process is performed.

[0050] (Gas defrosting process) As described above, when the fan 12 is operating and the refrigerator compartment damper 14 is open, the gas that has passed through the evaporator 24 disposed in the cooling flow path 10 (lower cooling flow path 10A) flows from the cooling flow path 10 (upper cooling flow path 10B) into the refrigerator compartment 7, circulates inside the refrigerator compartment 7, and then returns to the lower side of the evaporator 24 disposed in the cooling flow path 10 (lower cooling flow path 10A) via the return flow path 15. At this time, the gas circulating inside the refrigerator compartment 7 removes heat from the stored items and the like inside the refrigerator compartment, so that the temperature of the gas has risen when it flows into the return flow path 15. When this gas with a higher temperature passes through the evaporator 24 again, it can warm the evaporator 24.

[0051] In particular, since the gas with an increased temperature passes through the lower region of the heat exchange pipe 24A, it is possible to effectively prevent the gas from condensing and accumulating on the lower side, thereby enabling effective defrosting in the entire evaporator 24 including the outlet 24A2 side of the heat exchange pipe 24A.

[0052] (Control system for defrosting process) FIG. 4 is a diagram showing a control system 100 related to defrosting of the refrigerator 1 according to one embodiment of the present invention. Next, the control system 100 for performing the above-mentioned defrosting process will be described with reference to FIG. 4. The control system 100 constitutes a part of the control system of the refrigerator 1. The control system 100 receives measurement data (signals) from a temperature sensor 50 (see FIG. 1) arranged in the refrigerator compartment 50. The control system 100 also receives timing data (signals) from a timer 51. Furthermore, the control system 100 transmits control signals to the compressor 21, the fan 12, the freezer compartment damper 13, the refrigerator compartment damper 14, and the switching valve (three-way valve) 31.

[0053] (Control when performing hot gas defrosting process and gas defrosting process) 5A is a time chart showing control when hot gas defrosting process and gas defrosting process are performed. In the refrigerator 1 according to this embodiment, the control system 100 performs a first defrosting process in which the hot gas defrosting process and gas defrosting process are performed, and a second defrosting process in which the gas defrosting process is stopped and only the hot gas defrosting process is continued.

[0054] In normal operation, the compressor 21 and the fan 12 are turned on and off, and the freezer damper 13 and the refrigerator damper 14 are opened and closed as appropriate, depending on the temperature condition inside the freezer. When cooling the freezer chamber 6, the compressor 21 and the fan 12 are turned on and the freezer damper 13 is opened, so that the gas that has passed through the evaporator 24 can be supplied to the freezer chamber 6 to cool it. When cooling the refrigerator chamber 7, the compressor 21 and the fan 12 are turned on and the refrigerator damper 14 is opened, so that the gas that has passed through the evaporator 24 can be supplied to the refrigerator chamber 7 to cool it. When the compressor 21 and the fan 12 are turned on and the freezer damper 13 and the refrigerator damper 14 are opened, so that the gas that has passed through the evaporator 24 can be supplied to the freezer chamber 6 and the refrigerator chamber 7 to cool both chambers. In either case, in normal operation, the changeover valve (three-way valve) 31 is held in a closed state.

[0055] When defrosting, a first defrosting process is performed in which both hot gas defrosting and gas defrosting are performed first. Specifically, the changeover valve (three-way valve) 31 is opened while the compressor 21 is on, or the changeover valve (three-way valve) 31 is opened and then the compressor 21 is turned on, thereby performing a hot gas defrosting process in which a hot gaseous refrigerant is supplied to the evaporator 24 via the hot gas bypass pipe 31.

[0056] At the same time, with the fan 12 on, the refrigerator compartment damper 14 is opened to supply gas from the cooling flow path 10 to the refrigerator compartment 7, and the gas whose temperature has increased by circulating in the refrigerator compartment 7 is supplied to the lower side of the evaporator 24 to perform a gas defrosting process. This starts a first defrosting process that performs both the hot gas defrosting process and the gas defrosting process. At this time, the freezer compartment damper 13 is always closed to prevent the gas whose temperature has increased from flowing into the freezer compartment 6.

[0057] If the gas defrosting process is continued, the temperature of the gas circulating in the refrigerator compartment 7 will rise, and there is a possibility that the temperature in the refrigerator compartment 7 will rise too much. For this reason, after the first defrosting process is started, when a certain period of time has elapsed, the gas defrosting process is stopped and a second defrosting process is performed in which only the hot gas defrosting process is continued. In this case as well, the freezer compartment damper 13 is kept constantly closed to prevent the gas with a raised temperature from flowing into the freezer compartment 6.

[0058] If a movable fan cover is used to cover the outside of the fan 12, the fan cover is always kept closed in the first defrosting process and the second defrosting process to prevent the heated gas from flowing into the freezer chamber 6.

[0059] The timing of switching from the first defrosting process to the second defrosting process can be determined, for example, by performing a control process of stopping the gas defrosting process by turning off the fan 12 and closing the refrigerator compartment damper 14 when a predetermined time has elapsed using timing data from the timer 51. Also, when the temperature measured by the temperature sensor 50 arranged in the refrigerator compartment 7 reaches a predetermined temperature, a control process of stopping the gas defrosting process by turning off the fan 12 and closing the refrigerator compartment damper 14 can be performed.

[0060] Furthermore, the timing to switch from the first defrosting process to the second defrosting process can be determined using information from both the timer 51 and the temperature sensor 50. If, in the second defrosting process, a storage compartment into which gas may flow is provided other than the freezer compartment 6 and the refrigerator compartment 7, the refrigerator compartment damper 14 may be closed but the fan 12 may continue to operate.

[0061] After starting the second defrosting process in which only the hot gas defrosting process is performed, the second defrosting process can be terminated when a predetermined time has elapsed based on the timing information from the timer 51. Specifically, the changeover valve (three-way valve) 31 that was in the open state is closed to stop the hot gas defrosting process and return the cooling circuit 20 to the normal operation mode. By the above-mentioned first and second defrosting processes, the evaporator 24 can be effectively defrosted while preventing the temperature in the refrigerator compartment 7 from rising excessively.

[0062] When the cooling circuit 20 returns to normal operation mode and the evaporator 24 is cooled again, the fan 12 is turned on and the freezer compartment damper 13 and the refrigerator compartment damper 14 are opened, thereby cooling the freezer compartment 6 and the refrigerator compartment 7.

[0063] 1 shows the temperature sensor 50 disposed above the refrigerator compartment 7, but this is not limiting and the temperature sensor 50 can be disposed at any position within the refrigerator compartment 7. Also, a temperature sensor can be disposed within the cooling flow path 10, and the timing for switching from the first defrosting process to the second defrosting process can be determined based on temperature data from the temperature sensor.

[0064] 5B is a time chart showing control when only hot gas defrosting is performed. For reference, conventional control when only hot gas defrosting is performed is as follows. The hot gas defrosting process is started by opening the switching valve (three-way valve) 31 while the compressor 21 is on, or by opening the switching valve (three-way valve) 31 and then turning on the compressor 21. After a certain period of time has elapsed, the switching valve (three-way valve) 31 is closed to end the hot gas defrosting process.

[0065] In the above embodiment, the refrigerator compartment 7 is located above the evaporator 24, and the gas that has flowed through the refrigerator compartment 7 is returned to the lower side of the evaporator 24 via the return flow path 15, but this is not limited to the above. For example, if the refrigerator compartment 7 is located at the position where the freezer compartment 6 in Fig. 1 is located, the gas that has flowed through the refrigerator compartment 7 will flow directly into the lower side of the evaporator 24.

[0066] In the above embodiment, a three-way valve is used as the switching valve 31, but the present invention is not limited to this. For example, a function similar to that of a three-way valve can be obtained by attaching a T-shaped pipe to the branch point and providing an on-off valve on the branch side (hot gas bypass pipe 30 side). In this case, the on-off valve functions as the switching valve 31.

[0067] As described above, the refrigerator according to the present invention includes the refrigerator compartment 7, the cooling circuit 20 in which a cooling cycle is performed in which the refrigerant flows through the compressor 21, the condenser 22, and the evaporator 24 in this order and returns to the compressor 21, the hot gas bypass pipe 30 directly connecting the outlet side of the compressor 21 and the inlet side of the evaporator 24, and the fan 12 for moving the gas inside the refrigerator. The fan 12 circulates the gas so that the gas that has passed through the evaporator 24 flows from bottom to top into the refrigerator compartment 7 and the gas that has flowed inside the refrigerator compartment 7 returns to the lower side of the evaporator 24 again. The inlet 24A1 and the outlet 24A2 of the heat exchange pipe 24A of the evaporator 24 through which the refrigerant flows are disposed above the evaporator 24. The first defrosting process is performed to perform a hot gas defrosting process in which the refrigerant discharged from the compressor 21 is supplied to the inlet 24A1 of the heat exchange pipe 24A via the hot gas bypass pipe 30, and a gas defrosting process in which the gas that has flowed inside the refrigerator compartment 7 is supplied to the lower side of the evaporator 24.

[0068] When only hot gas defrosting processing is performed, there is a risk that the refrigerant will condense and accumulate below the evaporator, but in gas defrosting processing, gas that has flowed through refrigerator compartment 7 and has increased in temperature is supplied to the lower side of evaporator 24, thereby warming the area below evaporator 24 and suppressing condensation of the refrigerant and preventing the refrigerant from accumulating below evaporator 24. Thus, it is possible to provide a refrigerator that can perform defrosting processing of the evaporator efficiently in a short time by using a hot gas refrigerant.

[0069] Furthermore, the refrigerator 1 according to this embodiment stops the gas defrosting process when a predetermined time has elapsed after starting the first defrosting process or when the temperature of the gas flowing through the refrigerator compartment 7 reaches a predetermined temperature, and implements a second defrosting process in which only the hot gas defrosting process is performed.

[0070] If the gas defrosting process using the gas flowing through the refrigerator compartment 7 is continued, the temperature of the circulating gas increases, which may cause a rise in the temperature inside the refrigerator compartment 7. However, when a predetermined time has elapsed or when the temperature of the gas flowing through the refrigerator compartment 7 has reached a predetermined temperature, the gas defrosting process is stopped and only the hot gas defrosting process is performed, whereby the defrosting process of the evaporator 24 can be efficiently performed while suppressing a rise in the temperature of the refrigerator compartment 7.

[0071] The refrigerator 1 according to the present embodiment further includes a changeover valve 31 that switches between an open state in which the refrigerant discharged from the compressor 21 flows to the hot gas bypass pipe 30 side and a closed state in which the refrigerant discharged from the compressor 21 flows to the condenser 22 side and a normal operation is performed, a refrigerator compartment damper 14 that switches between an open state in which gas flows from the cooling flow path 10 in which the evaporator 24 is arranged to the refrigerator compartment 7 and a closed state in which gas does not flow from the cooling flow path 10 to the refrigerator compartment 7, and a control unit 100 that controls the compressor 21, the fan 12, the changeover valve 31, and the refrigerator compartment damper 14. The control unit 100 opens the changeover valve 31 when the compressor 21 is on, and opens the refrigerator compartment damper 14 when the fan 12 is on to start a first defrosting process, and when a predetermined time has elapsed or when the temperature of the gas flowing through the refrigerator compartment 7 has reached a predetermined temperature, closes at least the refrigerator compartment damper 14 to switch from the first defrosting process to a second defrosting process.

[0072] In this manner, the control unit 100 controls the compressor 21, the fan 12, the switching valve 31, and the refrigerator compartment damper 14, so that the first defrosting process and the second defrosting process can be performed reliably.

[0073] Furthermore, in the refrigerator 1 according to this embodiment, the control unit 100 switches from the first defrosting process to the second defrosting process based on the timing data from the timer 51 or the measurement data from the temperature sensor 50 arranged in the refrigerator compartment 7, so that the first defrosting process can be switched to the second defrosting process at the right timing.

[0074] In addition, the refrigerator 1 of this embodiment further includes a freezer compartment 6, and a freezer compartment damper 13 that switches between an open state in which gas flows from the cooling flow path 10 to the freezer compartment 6, and a closed state in which gas does not flow from the cooling flow path 10 to the freezer compartment 6, and the control unit 100 maintains the freezer compartment damper 13 in the closed state while performing the first defrosting process and the second defrosting process.

[0075] This makes it possible to carry out the first defrosting process and the second defrosting process while reliably suppressing the temperature in the freezer compartment 6 from increasing.

[0076] Although the embodiments and modes of implementation of the present invention have been described, the disclosed contents may vary in details of the configuration, and changes in the combination and order of elements in the embodiments and modes of implementation may be realized without departing from the scope and spirit of the claimed invention. [Explanation of symbols]

[0077] 1. Refrigerator 2. Chassis 3 Upper door 4 Lower door 6 Freezer 7. Refrigerator 10 Cooling Channel 10A lower cooling channel 10B Upper cooling passage 11A Lower partition plate 11B Upper partition plate 12 Fan 13 Freezer damper 14 Refrigerator damper 15 Return flow path 15A Entrance 15B Exit 20 Cooling circuit 21 Compressor 22 Condenser 23 Capillary tube 24 Evaporator 24A Heat exchange pipe 24A1 Entrance 24A2 Exit 25, 26, 27 Piping 28 Suction pipe 30 Hot gas bypass pipe 31 Switching valve (three-way valve) 40 Machine room 50 Temperature Sensor 51 Timer 100 Control section

Claims

1. A refrigerator compartment, a cooling circuit in which a cooling cycle is implemented in which a refrigerant flows through a compressor, a condenser, an evaporator, and then returns to the compressor; a hot gas bypass pipe that directly connects the outlet side of the compressor and the inlet side of the evaporator; A fan for circulating gas inside the storage compartment; The fan circulates the gas so that the gas that has passed through the evaporator flows from bottom to top into the refrigerator compartment, and the gas that has flowed through the refrigerator compartment returns to the lower side of the evaporator again. The inlet and the outlet of the heat exchange pipe of the evaporator through which the refrigerant flows are disposed above the evaporator, a first defrosting process is carried out to perform a hot gas defrosting process in which the refrigerant discharged from the compressor is supplied to an inlet of the heat exchange pipe via the hot gas bypass pipe, and a gas defrosting process is carried out to supply gas that has flowed inside the refrigerator compartment to a lower side of the evaporator; a second defrosting process in which the gas defrosting process is stopped and only the hot gas defrosting process is performed when a predetermined time has elapsed or when a temperature of the gas flowing through the refrigerator compartment reaches a predetermined temperature after the first defrosting process is started.

2. a switching valve that switches between an open state in which the refrigerant discharged from the compressor flows to the hot gas bypass pipe side to perform the hot gas defrosting process and a closed state in which the refrigerant discharged from the compressor flows to the condenser side to perform a normal operation; a refrigeration chamber damper that switches between an open state in which gas flows from a cooling flow passage in which the evaporator is disposed to the refrigeration chamber and a closed state in which gas does not flow from the cooling flow passage to the refrigeration chamber; A control unit that controls the compressor, the fan, the switching valve, and the refrigeration chamber damper; Further comprising: The control unit:

2. The refrigerator according to claim 1, wherein the first defrosting process is started by opening the changeover valve while the compressor is on and by opening the refrigerator compartment damper while the fan is on, and when a predetermined time has elapsed or when a temperature of gas flowing through the refrigerator compartment has reached a predetermined temperature, at least the refrigerator compartment damper is closed, thereby switching from the first defrosting process to the second defrosting process.

3. The control unit:

3. The refrigerator according to claim 2, wherein the first defrosting process is switched to the second defrosting process based on time data from a timer or measurement data from a temperature sensor disposed in the refrigerator compartment.

4. A freezer and a freezing chamber damper switchable between an open state in which gas flows from the cooling flow path to the freezing chamber and a closed state in which gas does not flow from the cooling flow path to the freezing chamber; Further comprising: The control unit:

4. The refrigerator according to claim 2, wherein the freezer compartment damper is maintained in a closed state while the first defrosting process and the second defrosting process are being carried out.

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