Refrigerator

Abstract

A refrigerator includes a refrigerating chamber, a cooling circuit in which a cooling cycle is implemented in which refrigerant sequentially flows through a compressor, a condenser, an evaporator and returns to the compressor again, a hot gas bypass pipe directly connecting an out side of the compressor and an in side of the evaporator, and a fan for flowing gas in the refrigerator, the gas is circulated by the fan as follows: gas flowing through the evaporator from the lower side to the upper side flows into the refrigerating chamber, the gas flowing in the refrigerating chamber returns to the lower side of the evaporator again, an inlet and an outlet of a heat exchange pipe of the evaporator for the flow of the refrigerant are provided at the upper side of the evaporator, a first defrosting program is implemented in which a hot gas defrosting process in which refrigerant discharged from the compressor is supplied to the inlet of the heat exchange pipe through the hot gas bypass pipe is performed, and a gas defrosting process in which gas flowing in the refrigerating chamber 7 is supplied to the lower side of the evaporator is also performed.

Description

Technical Field

[0001] This invention relates to a refrigerator, and more particularly to a refrigerator that uses hot gaseous refrigerant to remove frost adhering to the evaporator. Background Technology

[0002] The evaporator, which forms part of the cooling circuit of a refrigerator, can accumulate frost due to the cooling of surrounding water vapor, posing a risk of reduced cooling performance. To address this, a hot gas bypass pipe is provided downstream of the compressor, which forms part of the cooling circuit, and connected to the upstream side of the evaporator. Hot gas defrosting is known, where hot gas is temporarily passed through the evaporator via the hot gas bypass pipe to heat it up for defrosting (see, for example, Patent Document 1). In Patent Document 1, the evaporator is heated for defrosting by directly supplying hot gaseous refrigerant discharged from the compressor to the inlet of the heat exchange pipe of the evaporator.

[0003] (Existing technical literature)

[0004] (Patent Documents)

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

[0006] However, in the hot gas defrosting process described in Patent Document 1, the temperature difference between the supplied hot gaseous refrigerant and the heat exchange pipes is relatively large, causing refrigerant condensation to occur within the heat exchange pipes. The heat exchange pipes of the evaporator typically meander from the upper inlet of the evaporator to the lower side, then back up to reach the outlet. Consequently, the condensed refrigerant accumulates on the lower side of the evaporator, resulting in a slower temperature rise at the outlet of the heat exchange pipes, thus posing a risk of prolonged defrosting time.

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

[0008] The purpose of this invention is to provide a refrigerator that can use hot gaseous refrigerant to efficiently defrost the evaporator in a short time.

[0009] To achieve the above objectives, the present invention provides a refrigerator comprising:

[0010] Refrigeration compartment;

[0011] A cooling circuit in which a cooling cycle is implemented, in which the refrigerant flows sequentially through the compressor, condenser, and evaporator and then returns to the compressor;

[0012] A hot gas bypass pipe, which directly connects the outlet side of the compressor to the inlet side of the evaporator; and

[0013] A fan, used to circulate air inside the refrigerator;

[0014] The feature is that the gas is circulated by the fan as follows: gas flowing through the evaporator flows upward into the refrigerator compartment, and gas flowing through the refrigerator compartment returns to the lower side of the evaporator.

[0015] The inlet and outlet of the heat exchange pipes for refrigerant flow in the evaporator are located on the upper side of the evaporator.

[0016] The first defrosting procedure is implemented, wherein hot gas defrosting is performed on the refrigerant discharged from the compressor, which is supplied to the inlet of the heat exchange pipe through the hot gas bypass pipe, and gas defrosting is performed on the gas flowing in the refrigerator compartment, which is supplied to the lower side of the evaporator.

[0017] Therefore, when using hot gaseous refrigerant for hot defrosting, the temperature of the evaporator's heat exchange pipes is relatively low, posing a risk of refrigerant condensation and accumulation on the lower side of the evaporator. However, according to the present invention, by supplying the lower side of the evaporator with warm gas flowing in the refrigerator compartment, the area on the lower side of the evaporator can be warmed, suppressing refrigerant condensation and preventing refrigerant accumulation on the lower side of the evaporator. Thus, a refrigerator capable of efficiently defrosting the evaporator using hot gaseous refrigerant can be provided in a shorter time.

[0018] Furthermore, after the first defrosting procedure begins, a second defrosting procedure is implemented after a specified time has elapsed or when the temperature of the gas flowing in the refrigerator compartment reaches a specified temperature, wherein the gas defrosting process is stopped and only the hot gas defrosting process is performed.

[0019] Thus, as the gas defrosting process using the gas flowing in the refrigerator compartment continues, the temperature of the circulating gas rises, posing a risk of temperature increase within the refrigerator compartment. According to the present invention, the gas defrosting process is stopped after a specified time has elapsed or when the temperature of the gas flowing in the refrigerator compartment reaches a specified temperature, and only hot gas defrosting is performed. This suppresses temperature rise in the refrigerator compartment while efficiently defrosting the evaporator.

[0020] Furthermore, the refrigerator also includes:

[0021] A switching valve that switches between an open state and a closed state, wherein in the open state, refrigerant discharged from the compressor flows to the hot gas bypass pipe side to perform the hot gas defrosting process, and in the closed state, refrigerant discharged from the compressor flows to the condenser side to perform normal operation;

[0022] A refrigerator compartment damper that switches between an open and a closed state, wherein in the open state, gas flows from the cooling path where the evaporator is located to the refrigerator compartment, and in the closed state, gas does not flow from the cooling path to the refrigerator compartment; and

[0023] A control unit for controlling the compressor, the fan, the switching valve, and the refrigerator compartment damper;

[0024] The control unit starts the first defrosting program as follows: while the compressor is on, the switching valve is opened, and the refrigerator compartment damper is opened while the fan is on. After a predetermined time has elapsed or when the temperature of the gas flowing in the refrigerator compartment reaches a preset temperature, the control unit switches from the first defrosting program to the second defrosting program by at least closing the refrigerator compartment damper.

[0025] In this way, by controlling the compressor, fan, switching valve and refrigerator compartment damper through the control unit, the first defrosting program and the second defrosting program can be reliably carried out.

[0026] Furthermore, the control unit switches from the first defrost program to the second defrost program based on timing data from a timer or measurement data from a temperature sensor installed in the refrigerator compartment.

[0027] In this way, based on data from a timer or temperature sensor, the switch from the first defrost program to the second defrost program can be performed at the precise time.

[0028] Furthermore, the refrigerator also includes a freezer compartment and a freezer compartment damper that can switch between an open state and a closed state. In the open state, gas flows from the cooling path to the freezer compartment, and in the closed state, gas does not flow from the cooling path to the freezer compartment. The control unit keeps the freezer compartment damper in the closed state during the execution of the first defrost procedure and the second defrost procedure.

[0029] In this way, by keeping the freezer compartment damper closed, the temperature rise in the freezer compartment can be reliably suppressed while the first or second defrost procedure is being performed.

[0030] The beneficial effect of the present invention is that the refrigerator of the present invention can use hot gaseous refrigerant to perform evaporator defrosting in a shorter time and more efficiently. Attached Figure Description

[0031] Figure 1 This is a side sectional view of the refrigerator of the present invention.

[0032] Figure 2 This is a block diagram of the cooling circuit of the refrigerator of the present invention.

[0033] Figure 3 This is a diagram of the piping near the evaporator in the refrigerator of this invention.

[0034] Figure 4 This is a block diagram of the defrosting control system of the refrigerator of the present invention.

[0035] Figure 5A This is a control timing diagram for hot gas defrosting and gas defrosting.

[0036] Figure 5B This is the control timing diagram for hot gas defrosting only. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] Hereinafter, the refrigerator 10 of the present invention will be described in detail with reference to the accompanying drawings. In the description of this embodiment, the same reference numerals will be used for the same components in principle, and repeated descriptions will be omitted. Furthermore, in the following description, the directions of up, down, front, back, left, and right will be used for explanation, but "left and right" refers to the left and right when viewing the refrigerator 10 from the front.

[0039] Figure 1 This is a side sectional view of the refrigerator 1 of the present invention. First, refer to... Figure 1 This will be used to describe the general features of the refrigerator 1 of the present invention.

[0040] The refrigerator 1 has an outer casing 2. When placed on a horizontal surface, the front portion of the outer casing 2 includes an upper door 3 and a lower door 4 that are rotatably mounted. The interior of the outer casing 2 (hereinafter referred to as the "refrigerator interior") contains a freezer compartment 6 and a refrigerator compartment 7. Insulation material is provided between the inner surface of the outer casing 2 and the outer surfaces of the freezer compartment 6 and the refrigerator compartment 7.

[0041] <Cooling flow path>

[0042] like Figure 1 As shown, a cooling flow path 10 is provided behind the freezer compartment 6 and the refrigerator compartment 7, which consists of a lower cooling flow path 10A and an upper cooling flow path 10B separated by partitions 11A and 11B, respectively. An evaporator 24 is provided in the cooling flow path 10 (specifically the lower cooling flow path 10A). As described later, the evaporator 24 forms part of the cooling circuit 20 of the refrigerator 1. A fan 12 is provided above the evaporator 24 within the cooling flow path 10. The fan 12 can circulate the gas inside the refrigerator, and the gas cooled by the evaporator 24 can be supplied from the cooling flow path 10 to the freezer compartment 6 or the refrigerator compartment 7.

[0043] A freezer compartment damper 13 is provided at the opening on the upper side of the lower partition plate 11A. When the freezer compartment damper 13 is open, gas passing through the evaporator 24 flows from the cooling flow path 10 (lower cooling flow path 10A) to the freezer compartment 6. Conversely, when the freezer compartment damper 13 is closed, gas passing through the evaporator 24 is prevented from flowing from the cooling flow path 10 (lower cooling flow path 10A) to the freezer compartment 6. Figure 1 As shown, the freezer compartment damper 13 is in the closed state.

[0044] With the freezer compartment damper 13 open, the fan 12 is driven, causing the gas flowing into the freezer compartment 6 from the cooling flow path 10 (lower cooling flow path 10A) to circulate within the freezer compartment 6 and return to the cooling flow path 10 (lower cooling flow path 10A) through the opening on the lower side of the lower partition plate 11A. In this way, the gas is cooled again by passing through the evaporator 24, repeating the same flow cycle. This allows the stored items in the freezer compartment 6 to be cooled.

[0045] However, the method is not limited to using the freezer compartment damper 13 to switch whether gas flows into the freezer compartment 6. For example, a movable fan cover covering the outside of the fan 12 can also be used. This allows gas discharged from the fan 12 to flow into the freezer compartment 6 when the fan cover is open, and gas discharged from the fan 12 to not flow into the freezer compartment 6 when the fan cover is closed.

[0046] Furthermore, a refrigerator compartment damper 14 is provided between the lower cooling flow path 10A and the upper cooling flow path 10B. When the refrigerator compartment damper 14 is open, gas passing through the evaporator 24 flows from the lower cooling flow path 10A to the upper cooling flow path 10B. Furthermore, gas flowing into the upper cooling flow path 10B flows into the refrigerator compartment 7 from the cooling flow path 10 (upper cooling flow path 10B) through various openings provided at multiple height positions. On the other hand, when the refrigerator compartment damper 14 is closed, gas passing through the evaporator 24 does not flow from the lower cooling flow path 10A to the upper cooling flow path 10B. Figure 1 In the image, the refrigeration compartment damper 14 is in the open state, and the airflow at this time is shown by a dotted arrow.

[0047] Driven by fan 12, with refrigerator compartment damper 14 open, gas flowing into refrigerator compartment 7 from cooling flow path 10 (upper cooling flow path 10B) circulates within refrigerator compartment 7 and flows into inlet 15A of return flow path 15, which opens at the lower side of refrigerator compartment 7. During the circulation of gas through evaporator 24 within refrigerator compartment 7, the stored items in freezer compartment 6 can be cooled.

[0048] <Return to Flow Path>

[0049] The return flow path 15 is configured such that the gas circulating in the refrigerator compartment 7 does not flow within the freezer compartment 6, but instead flows into the lower side of the cooling flow path 10 (lower cooling flow path 10A). The return flow path 15 is spaced apart from the cooling flow path 10. Gas flowing into the refrigerator compartment 7 from the cooling flow path 10 (upper cooling flow path 10B) and circulating within the refrigerator compartment 7 flows into the return flow path 15 from the inlet 15A. Then, the flowing gas flows within 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 located within the cooling flow path 10 (lower cooling flow path 10A). In this way, the gas is cooled again by passing through the evaporator 24, repeating the same flow cycle. In this way, the stored items in the refrigerator compartment 7 can be cooled.

[0050] At the lower rear of the outer casing 2, there is a mechanical chamber 40, which contains a compressor 21, a condenser 22, an evaporating dish (not shown), etc.

[0051] Cooling Circuit

[0052] Figure 2 This is a block diagram illustrating the configuration of the cooling circuit 20 in the refrigerator 1 of the present invention. (See below for further details.) Figure 2 This will explain the general situation of cooling circuit 20.

[0053] 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 order described above by piping as described later, forming a first refrigerant flow path for circulating refrigerant within the cooling circuit 20. Figure 2 The arrows shown indicate the direction of refrigerant flow.

[0054] Compressor 21 compresses the gaseous refrigerant, bringing it to a high-temperature, high-pressure state. The compressed refrigerant is then sent to condenser 22 via piping 25. Piping 25 is equipped with a switching valve (three-way valve) 31, as described later, dividing piping 25 into piping 25a and piping 25b. Compressor 21 includes an inverter, which can adjust the amount of refrigerant discharged per unit time by changing the rotational speed, thereby controlling the cooling capacity of cooling circuit 20. Condenser 22 releases the heat from the refrigerant compressed by compressor 21, condensing the refrigerant. The condensed refrigerant is then sent to capillary tube 23 via piping 26.

[0055] The capillary tube 23 reduces the pressure of the refrigerant condensed by the condenser 22, causing it to expand and thus lowering its temperature. The expanded refrigerant is then sent to the heat exchange pipe 24A of the evaporator 24 via piping 27. In the heat exchange pipe 24A, where heat exchange is facilitated by fins, the refrigerant, depressurized by the capillary tube 23, evaporates and absorbs heat. The evaporated refrigerant, now in a gaseous state, is sent to the compressor 21 via suction pipe 28 and is compressed again. The cooling circuit 20 operates in this way. According to this embodiment, the capillary tube 23 is connected to the condenser 22 and the evaporator 24 via piping 26 and piping 27, but piping 26 and 27 may also be included within the capillary tube 23.

[0056] The suction tube 28 for the flow of refrigerant from the evaporator 24 to the compressor 21 is disposed close to at least part of the capillary tube 23, so that heat exchange can be performed between the tube and the capillary tube 23. Figure 2 The area 29 enclosed by the dotted line in the figure represents the general layout of the heat exchange section.

[0057] When the evaporator 24 exchanges heat with the gas flowing inside the refrigerator 1, it may become frosted by water vapor contained in the gas. Therefore, in order to defrost the evaporator 24, the refrigerator 1 of this embodiment performs hot gas defrosting and gas defrosting processes as described below. In the hot gas defrosting process, hot gaseous refrigerant compressed by the compressor 21 is used. For this purpose, the cooling circuit 20 includes a hot gas bypass pipe 30, which is connected to the piping 25 connecting the downstream of the compressor 21 and the upstream of the condenser 22. This connection is provided with a switching valve (three-way valve) 31, which can change the direction of the refrigerant supplied from the compressor 21 through the piping 25a, directing it to either the condenser 22 (i.e., piping 25b) or the hot gas bypass pipe 30. In this way, it is possible to control 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 the piping downstream of the capillary tube 23 and upstream of the evaporator 24.

[0058] Unlike the first refrigerant flow path described above, which involves the refrigerant flowing through compressor 21-pipe 25-condenser 22-pipe 26-capillary tube 23-pipe 27-evaporator 24, the hot gas bypass pipe 30 constitutes a second refrigerant flow path, which involves the refrigerant flowing through compressor 21-pipe 25-hot gas bypass pipe 30-pipe 27-evaporator 24. According to this embodiment, the upstream end of the hot gas bypass pipe 30 is connected to pipe 25, but this configuration is not limited to. For example, the upstream end of the hot gas bypass pipe 30 may also be connected to pipe 26, which connects the downstream of condenser 22 and the upstream of capillary tube 23.

[0059] The switching valve (three-way valve) 31 is controlled by the control unit 100 (reference). Figure 4The control unit 100 controls the switching valve (three-way valve) 31 so that the refrigerant discharged from the compressor 21 through the piping 25a flows to the condenser 22 (i.e., piping 25b) during normal operation, and flows to the hot gas bypass pipe 30 during the hot gas defrosting process described later.

[0060] In this specification, the state in which the refrigerator 1 normally operates (i.e., operates to cool the interior of the refrigerator or to maintain the temperature inside the refrigerator) is referred to as "normal operation". Furthermore, the state in which the refrigerator 1 operates to defrost the evaporator 24 (i.e., the state in which the switching valve (three-way valve) 31 is opened, allowing refrigerant to flow from the switching valve (three-way valve) 31 to the hot gas bypass pipe 30, and the refrigerator operates to allow hot gas to flow to the evaporator 24) is referred to as "hot gas defrosting".

[0061] Piping near the evaporator

[0062] Figure 3 This is a diagram of the piping near the evaporator 24 in the refrigerator 1 of this invention. (See diagram below.) Figure 3 As shown, capillary tube 23 is connected to the inlet 24A1 of heat exchange pipe 24A of evaporator 24 via piping 27. The outlet 24A2 of heat exchange pipe 24A of evaporator 24 is connected to suction pipe 28. The inlet 24A1 and outlet 24A2 of heat exchange pipe 24A of evaporator 24 are both located on the upper side of evaporator 24.

[0063] Furthermore, piping 27 connects to the hot gas bypass pipe 30 upstream of the connection with evaporator 24. Figure 3 In the diagram, the through section 32 is located upstream of the pipe 27 (or capillary tube 23) and the hot gas bypass pipe 30. The pipe 27 (or capillary tube 23) and the hot gas bypass pipe 30 are configured to connect to the area on the lower side of the housing 2 through the through section 32.

[0064] The hot gas bypass pipe 30 is not used during normal operation of the refrigerator 1. However, during normal operation, at least a portion of the refrigerant becomes liquid 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 the opposite direction to the normal flow direction of the refrigerant.

[0065] A specified amount of refrigerant is injected into the cooling circuit 20 to achieve the specified cooling performance. Therefore, when the refrigerant flows back to the hot gas bypass pipe 30, the amount of refrigerant effective during normal operation of the cooling circuit 20 decreases, potentially failing to meet the specified cooling performance. Furthermore, due to the reduced cooling performance, the operating ratio of the cooling circuit 20 for cooling the evaporator 24 increases (e.g., an increase in the amount of refrigerant discharged from the compressor 21), thus potentially increasing electrical power consumption.

[0066] Therefore, in this embodiment, the hot air bypass pipe 30 of the refrigerator 1 (such as...) Figure 3 The device shown has a connecting portion 30a, which is configured to connect the hot gas bypass pipe 30 and the piping 27 (or capillary tube 23) (hereinafter referred to as the first piping) from the upper side in the vertical direction (up-down direction). Point A indicates the junction of the hot gas bypass pipe 30 and the first piping 27. The refrigerant flowing to the first piping 27, which is downstream of the capillary tube 23, is essentially flowing in a liquid state, and therefore tends to flow downwards in the vertical direction under the influence of gravity. Thus, due to the piping connection from the upper vertical direction, such as the connecting portion 30a of the hot gas bypass pipe 30 in this embodiment, the flow of refrigerant to the hot gas bypass pipe 30 can be suppressed.

[0067] In addition, such as Figure 3 As shown, the hot gas bypass pipe 30 may also be provided with a refrigerant backflow prevention section 30b. This refrigerant backflow prevention section 30b is placed in a part of the hot gas bypass pipe 30, and the upstream side of this part is erected approximately vertically relative to the downstream side. In this way, the upstream side of the hot gas bypass pipe 30 is located on the upper side in the vertical direction relative to the downstream side, and further upstream of this part, it is formed to descend vertically downward.

[0068] Because of its roughly U-shaped design, with a vertical rise followed by a fall and an open lower side, even if liquid refrigerant flows into the hot gas bypass pipe 30, the refrigerant is unlikely to cross the raised section downstream of the refrigerant backflow prevention section 30b and flow further upstream into the hot gas bypass pipe 30. This suppresses refrigerant flow upstream of the refrigerant backflow prevention section 30b and reduces the amount of refrigerant flowing into the hot gas bypass pipe 30 to below a certain level. Furthermore, instead of the refrigerant backflow prevention section 30b, a check valve can be installed at the pipe 30c that connects to the connection 30a of the hot gas bypass pipe 30 to suppress refrigerant flow upstream.

[0069] In this way, the cooling performance of the cooling circuit 20 can be suppressed, and the increase in power consumption can be suppressed. 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 (that is, taking into account the possibility of refrigerant reduction in the volume portion from point A to the refrigerant backflow prevention section 30b).

[0070] The refrigerant backflow prevention unit 30b is located at the lower rear of the outer casing 2 and is positioned in a location insulated from the outside air by foamed insulation material or the like. However, the piping near the evaporator 24 is not limited to the above-described case. Any other piping arrangement is conceivable as long as at least the inlet 24A1 and outlet 24A2 of the heat exchange pipe 24A of the evaporator 24 are located on the upper side of the evaporator 24 and the hot gas bypass pipe 30 is connected to the inlet 24A1 of the heat exchange pipe 24A.

[0071] <Hot air defrosting process>

[0072] As described above, the hot gaseous refrigerant leaving the compressor 21 is supplied to the inlet 24A1 of the heat exchange pipe 24A of the evaporator 24 through the hot gas bypass pipe 31, thereby enabling hot gas defrosting of the evaporator 24. The hot gaseous refrigerant flows within the heat exchange pipe 24A, heating the pipe and the fins through heat conduction. This melts the frost adhering to the evaporator 24, and the melted liquid falls down. The falling liquid is collected by a receiving dish located on the lower side of the evaporator 24 and flows into the evaporating dish within the machine chamber 40 through a drain pipe. The liquid flowing into the evaporating dish evaporates into the atmosphere.

[0073] like Figure 3 As shown, the heat exchange pipe 24A of the evaporator 24 meanders from the inlet 24A1 located on the upper side of the evaporator 24, extending to the lower side, and then meanders back to the upper side from the lowest point, reaching the outlet 24A2 located on the upper side of the evaporator 24. Figure 3 In the diagram, the heat exchange pipe 24AA is shown meandering back to the upper side, which is omitted from the diagram. That is, the inlet 24A1 and outlet 24A2 of the heat exchange pipe 24A are both located on the upper side of the evaporator 24.

[0074] In the case of hot gas defrosting only, due to the large temperature difference between the hot gaseous refrigerant and the heat exchange pipe 24A of the evaporator 24, the refrigerant condenses within the heat exchange pipe 24A, and the condensed refrigerant accumulates on the lower side of the evaporator 24. As a result, the temperature rise at the outlet of the heat exchange pipe 24A is slower, thus posing a risk of prolonged defrosting time. Therefore, in the refrigerator 1 of this embodiment, in addition to hot gas defrosting, a gas defrosting process as described below is also performed.

[0075] <Gas Defrosting Process>

[0076] As described above, when the refrigerator compartment damper 14 is open, the fan 12 is driven, causing gas passing through the evaporator 24 located in the cooling flow path 10 (lower cooling flow path 10A) to flow into the refrigerator compartment 7 from the cooling flow path 10 (upper cooling flow path 10B). After circulating within the refrigerator compartment 7, the gas returns to the lower side of the evaporator 24 located in the cooling flow path 10 (lower cooling flow path 10A) via the return flow path 15. At this time, since the gas circulating in the refrigerator compartment 7 absorbs heat from the stored items inside, the temperature of the gas rises when it flows into the return flow path 15. When this heated gas passes through the evaporator 24 again, it warms the evaporator 24.

[0077] In particular, since the heated gas passes through the area below the heat exchange pipe 24A, the problem of gas condensation and accumulation below can be effectively suppressed. This allows for effective defrosting throughout the evaporator 24, including the outlet 24A2 side of the heat exchange pipe 24A.

[0078] <Control system for defrosting>

[0079] Figure 4 This is a block diagram illustrating a control system 100 associated with defrosting a refrigerator 1 according to an embodiment of the present invention. Next, refer to... Figure 4 The following describes the control system 100 used to perform the defrosting process as described above. The control system 100 is part of the control system of the refrigerator 1. The control system 100 can operate from a temperature sensor 50 (reference 50) located in the refrigerator compartment 50. Figure 1 The control system 100 can receive measurement data (signals). Furthermore, the control system 100 can receive timing data (signals) from the timer 51. Further, the control system 100 can transmit control signals to the compressor 21, fan 12, freezer compartment damper 13, refrigerator compartment damper 14, and switching valve (three-way valve) 31.

[0080] <Control during hot gas defrosting and gas defrosting>

[0081] Figure 5A This is a control timing diagram for hot gas defrosting and gas defrosting. In the refrigerator 1 of this embodiment, a first defrosting procedure is performed by the control system 100, in which hot gas defrosting and gas defrosting are performed; and a second defrosting procedure is performed, in which gas defrosting is stopped and only hot gas defrosting continues.

[0082] During normal operation, the compressor 21 and fan 12 are switched on and off, and the freezer compartment damper 13 and refrigerator compartment damper 14 are opened and closed according to the temperature inside the refrigerator. When cooling the freezer compartment 6, with the compressor 21 and fan 12 on, opening the freezer compartment damper 13 allows gas passing through the evaporator 24 to be supplied to the freezer compartment 6 for cooling. When cooling the refrigerator compartment 7, with the compressor 21 and fan 12 on, opening the refrigerator compartment damper 14 allows gas passing through the evaporator 24 to be supplied to the refrigerator compartment 7 for cooling. With the compressor 21 and fan 12 on, opening the freezer compartment damper 13 and refrigerator compartment damper 14 allows gas passing through the evaporator 24 to be supplied to both the freezer compartment 6 and refrigerator compartment 7 for cooling. In all cases, during normal operation, the switching valve (three-way valve) 31 remains closed.

[0083] In the event of defrosting, the first defrosting procedure is performed, which includes both hot gas defrosting and gas defrosting. Specifically, hot gas defrosting is performed 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, by supplying hot gaseous refrigerant to the evaporator 24 through the hot gas bypass pipe 31.

[0084] Simultaneously, a gas defrosting process is performed. With fan 12 on, the refrigerator compartment damper 14 is opened, supplying gas from the cooling path 10 to the refrigerator compartment 7. The gas circulating within the refrigerator compartment 7 and experiencing temperature increases is then supplied to the lower side of the evaporator 24. This initiates the first defrosting procedure, combining hot gas defrosting and gas defrosting. During this time, the freezer compartment damper 13 remains closed to prevent the warming gas from flowing into the freezer compartment 6.

[0085] As the gas defrosting process continues, the temperature of the gas circulating in the refrigerator compartment 7 gradually rises, potentially causing the temperature inside the refrigerator compartment 7 to become excessively high. Therefore, after a certain period of time following the start of the first defrosting program, a second defrosting program is initiated, in which the gas defrosting process is stopped, and only the hot gas defrosting process continues. In this case, the freezer compartment damper 13 remains closed to prevent the rising temperature gas from flowing into the freezer compartment 6.

[0086] If a movable fan cover covering the outside of the fan 12 is used, the fan cover remains closed during the first and second defrost cycles, thereby preventing the flow of heated gas into the freezer compartment 6.

[0087] The timing for switching from the first defrosting program to the second defrosting program can be achieved, for example, by using timing data from timer 51. After a predetermined time has elapsed, the fan 12 can be shut off and the refrigerator compartment damper 14 can be closed to stop the gas defrosting process. Alternatively, the fan 12 can be shut off and the refrigerator compartment damper 14 can be closed to stop the gas defrosting process when the temperature measured by the temperature sensor 50 installed in the refrigerator compartment 7 reaches a preset temperature.

[0088] Furthermore, the timing for switching from the first defrost program to the second defrost program can be determined using messages from both the timer 51 and the temperature sensor 50. If, during the second defrost program, gas from outside the freezer compartment 6 and refrigerator compartment 7 can flow into the storage compartment, the refrigerator compartment damper 14 can be closed, but the fan 12 can continue to operate.

[0089] After the second defrosting procedure, which only involves hot gas defrosting, begins, it can be terminated at a predetermined time point based on the timing message from timer 51. Specifically, the open switching valve (three-way valve) 31 is closed, and the hot gas defrosting process is stopped, returning the cooling circuit 20 to its normal operating mode. Through the aforementioned first and second defrosting procedures, excessive temperature rise within the refrigerator compartment 7 can be prevented, while effectively defrosting the evaporator 24.

[0090] At the point when the cooling circuit 20 returns to its normal operating mode and the evaporator 24 is cooled again, the cooling of the freezer compartment 6 or the refrigerator compartment 7 can be achieved by turning off the fan 12 and opening the freezer compartment damper 13 or the refrigerator compartment damper 14.

[0091] exist Figure 1 In this refrigerator compartment 7, the temperature sensor 50 is located on the upper side; however, it is not limited to this and can be located anywhere within the refrigerator compartment 7. Furthermore, the temperature sensor is located within the cooling flow path 10, allowing the timing of switching from the first defrost program to the second defrost program to be determined based on temperature data from the sensor.

[0092] Figure 5B This is the control timing diagram for hot gas defrosting only. For reference, the control for hot gas defrosting only was previously performed as follows: Hot gas defrosting is initiated 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 period of time, the switching valve (three-way valve) 31 is closed to end the hot gas defrosting process.

[0093] In the above embodiment, the refrigerator compartment 7 is located above the evaporator 24, and the gas flowing in the refrigerator compartment 7 returns to the lower side of the evaporator 24 through the return flow path 15; however, this is not the only possibility. For example, in the refrigerator compartment 7... Figure 1 With the freezer compartment 6 positioned as is, the gas flowing in the refrigerator compartment 7 can flow into the lower side of the evaporator 24.

[0094] In the above embodiment, a three-way valve is shown as the switching valve 31, but it is not limited to this. For example, a T-tube can be installed at the bifurcation point, and an on / off valve can be provided on the bifurcation side (hot gas bypass pipe 30 side), thus achieving the same function as a three-way valve. In this case, the on / off valve functions as the switching valve 31.

[0095] As described above, the refrigerator of the present invention includes: a refrigerator compartment 7; a cooling circuit 20 in which a cooling cycle is performed, wherein refrigerant flows sequentially through a compressor 21, a condenser 22, and an evaporator 24 and returns to the compressor 21; a hot gas bypass pipe 30 directly connecting the outlet side of the compressor 21 and the inlet side of the evaporator 24; and a fan 12 for circulating gas within the refrigerator; the fan 12 circulates the gas as follows: gas flowing upward through the evaporator 24 into the refrigerator compartment 7, and the gas flowing within the refrigerator compartment 7 returns to the lower side of the evaporator 24; an inlet 24A1 and an outlet 24A2 of the heat exchange pipe 24A of the evaporator 24 for refrigerant flow are provided on the upper side of the evaporator 24; a first defrosting procedure is performed, wherein hot gas defrosting is performed where refrigerant discharged from the compressor 21 is supplied to the inlet 24A1 of the heat exchange pipe 24A through the hot gas bypass pipe 30, and gas defrosting is performed where gas flowing within the refrigerator compartment 7 is supplied to the lower side of the evaporator 24.

[0096] When using only hot gas defrosting, there is a risk that refrigerant condenses and accumulates on the underside of the evaporator. However, in gas defrosting, by supplying warmed gas flowing within the refrigerator compartment 7 to the underside of the evaporator 24, the area under the evaporator 24 is warmed, suppressing refrigerant condensation and preventing refrigerant accumulation. Therefore, a refrigerator capable of efficiently defrosting the evaporator in a shorter time using hot gaseous refrigerant can be provided.

[0097] Furthermore, in this embodiment, after the first defrosting program begins, the refrigerator 1 implements a second defrosting program when a predetermined time has elapsed or when the temperature of the gas flowing in the refrigerator compartment 7 reaches a preset temperature, wherein gas defrosting is stopped and only hot gas defrosting is performed.

[0098] As defrosting using the gas flowing through the refrigerator compartment 7 continues, the temperature of the circulating gas rises, posing a risk of temperature increase within the refrigerator compartment 7. However, after a predetermined time has elapsed or when the temperature of the gas flowing through the refrigerator compartment 7 reaches a predetermined temperature, the gas defrosting process is stopped, and only hot gas defrosting is performed. This suppresses the temperature rise in the refrigerator compartment 7 while efficiently defrosting the evaporator 24.

[0099] The refrigerator 1 in this embodiment also includes: a switching valve 31 that switches between an open state and a closed state; in the open state, refrigerant discharged from the compressor 21 flows to the hot gas bypass pipe 30 side to perform hot gas defrosting; in the closed state, refrigerant discharged from the compressor 21 flows to the condenser 22 side to perform normal operation; and a refrigerator compartment damper 14 that switches between an open state and a closed state; in the open state, gas flows from the cooling flow path 10, where the evaporator 24 is provided, to the refrigerator compartment 7; in the closed state, gas does not flow from the cooling flow path. 10 flows to the refrigerator compartment 7; and a control unit 100, which controls the compressor 21, fan 12, switching valve 31 and refrigerator compartment damper 14; the control unit 100 starts the first defrosting program in the following manner: while the compressor 21 is on, the switching valve 31 is opened, and the refrigerator compartment damper 14 is opened while the fan 12 is on; after a predetermined time has elapsed or when the temperature of the gas flowing in the refrigerator compartment 7 reaches a preset temperature, the program is switched from the first defrosting program to the second defrosting program by at least closing the refrigerator compartment damper 14.

[0100] In this way, by controlling the compressor 21, fan 12, switching valve 31 and refrigerator compartment damper 14 through the control unit 100, the first defrosting program and the second defrosting program can be reliably carried out.

[0101] Furthermore, in the refrigerator 1 of this embodiment, the control unit 100 switches from the first defrost program to the second defrost program based on the timing data of the timer 51 or the measurement data of the temperature sensor 50 installed in the refrigerator compartment 7, so that the switch from the first defrost program to the second defrost program can be performed at the right time.

[0102] In addition, the refrigerator 1 of this embodiment also includes: a freezer compartment 6; and a freezer compartment damper 13 that switches between an open state and a closed state. In the open state, gas flows from the cooling flow path 10 to the freezer compartment 6, and in the closed state, gas does not flow from the cooling flow path 10 to the freezer compartment 6. The control unit 100 keeps the freezer compartment damper 13 in the closed state during the execution of the first defrost procedure and the second defrost procedure.

[0103] In this way, the temperature rise of the freezer compartment 6 can be reliably suppressed while the first and second defrosting procedures are being implemented.

[0104] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A refrigerator comprising: Refrigeration compartment; A cooling circuit in which a cooling cycle is implemented, in which the refrigerant flows sequentially through the compressor, condenser, and evaporator and then returns to the compressor; A hot gas bypass pipe, which directly connects the outlet side of the compressor to the inlet side of the evaporator; and A fan, used to circulate air inside the refrigerator; The control unit is used to control the compressor and the fan; The characteristic feature is that the control unit circulates the gas via the fan as follows: gas passing through the evaporator flows upward into the refrigerator compartment, and the gas flowing through the refrigerator compartment returns to the lower side of the evaporator. The inlet and outlet of the heat exchange pipes for refrigerant flow in the evaporator are located on the upper side of the evaporator. The control unit controls the implementation of the first defrosting procedure, wherein hot gas defrosting is performed on the refrigerant discharged from the compressor and supplied to the inlet of the heat exchange pipe through the hot gas bypass pipe, and gas defrosting is performed on the gas flowing in the refrigerator compartment and supplied to the lower side of the evaporator. After the first defrosting procedure begins, when a predetermined time has elapsed or when the temperature of the gas flowing in the refrigerator compartment reaches a preset temperature, the control unit controls the implementation of a second defrosting procedure, wherein the gas defrosting process is stopped and only the hot gas defrosting process is performed.

2. The refrigerator according to claim 1, characterized in that, The refrigerator also includes: A switching valve that transitions between an open state and a closed state, wherein in the open state, refrigerant discharged from the compressor flows to the hot gas bypass side to perform the hot gas defrosting process, and in the closed state, refrigerant discharged from the compressor flows to the condenser side to perform normal operation; and A refrigerator compartment damper that switches between an open state and a closed state, wherein in the open state, gas flows from the cooling flow path where the evaporator is located to the refrigerator compartment, and in the closed state, gas does not flow from the cooling flow path to the refrigerator compartment; The control unit is also used to control the switching valve and the refrigerator compartment damper; The control unit starts the first defrosting program as follows: while the compressor is on, the switching valve is opened, and the refrigerator compartment damper is opened while the fan is on. After a predetermined time has elapsed or when the temperature of the gas flowing in the refrigerator compartment reaches a preset temperature, the control unit switches from the first defrosting program to the second defrosting program by at least closing the refrigerator compartment damper.

3. The refrigerator according to claim 2, characterized in that, The control unit switches from the first defrost program to the second defrost program based on timing data from a timer or measurement data from a temperature sensor installed in the refrigerator compartment.

4. The refrigerator according to claim 2 or 3, characterized in that, The refrigerator also includes a freezer compartment and a freezer compartment damper that can switch between an open state and a closed state. In the open state, gas flows from the cooling path to the freezer compartment, and in the closed state, gas does not flow from the cooling path to the freezer compartment. The control unit keeps the freezer compartment damper in the closed state during the execution of the first defrost procedure and the second defrost procedure.

5. The refrigerator according to claim 4, characterized in that, The hot gas bypass pipe is provided with a refrigerant backflow prevention part, which is located in a part of the hot gas bypass pipe and is in a U-shape that rises first and then falls and opens at the bottom.

6. The refrigerator according to claim 5, characterized in that, The refrigerant backflow prevention unit is located on the lower rear side of the refrigerator's outer shell and is positioned in a part that is insulated from the outside air by foamed insulation material.

7. The refrigerator according to claim 1, characterized in that, The heat exchange pipe meanders from the inlet located on the upper side of the evaporator to the lower side, then meanders back to the upper side from the lowest point to the outlet located on the upper side of the evaporator.

8. The refrigerator according to claim 7, characterized in that, The cooling circuit also includes a capillary tube, which is connected to the inlet of the heat exchange pipe of the evaporator via piping. The piping and the hot gas bypass pipe have a through section upstream, which connects to the area on the lower side of the refrigerator's outer shell.

9. The refrigerator according to claim 4, characterized in that, The cooling flow path is located behind the freezer and refrigerator compartments, and includes a lower cooling flow path and an upper cooling flow path separated by a lower and upper partition plate, respectively. When the freezer compartment damper is open, a fan is driven so that the gas flowing into the freezer compartment from the lower cooling flow path circulates in the freezer compartment and returns to the cooling flow path from the opening on the lower side of the lower partition plate.

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