WO2023284589A1

WO2023284589A1 - Refrigerator

Info

Publication number: WO2023284589A1
Application number: PCT/CN2022/103925
Authority: WO
Inventors: 大木达也; 和田芳彦; 馆野恭也
Original assignee: 海尔智家股份有限公司; 青岛海尔电冰箱有限公司; Aqua 株式会社
Priority date: 2021-07-15
Filing date: 2022-07-05
Publication date: 2023-01-19
Also published as: JP2023013290A; CN117751265A

Abstract

A refrigerator, comprising: a refrigeration compartment; a cooling loop, in which a cooling cycle is implemented, wherein, during the cooling cycle, a refrigerant successively flows through a compressor, a condenser, and an evaporator and again returns to the compressor; a hot gas bypass pipe, which is directly connected to a discharge side of the compressor and an intake side of the evaporator; and a fan, which is used for enabling a gas in the refrigerator to flow. The gas is circulated by the fan as follows: gas that passes through the evaporator from bottom to top flows into the refrigeration compartment, and the gas flowing in the refrigeration compartment again returns to a lower side of the evaporator; an inlet and an outlet of a heat exchange pipeline of the evaporator through which the refrigerant flows are matchingly disposed on an upper side of the evaporator; a first defrosting procedure is implemented, wherein hot gas defrosting treatment is performed, in which a refrigerant discharged from the compressor is supplied, by means of the hot gas bypass pipe, to the inlet of the heat exchange pipeline, and, at the same time, gas defrosting treatment is performed, in which gas flowing in the refrigeration compartment 7 is supplied to the lower side of the evaporator.

Description

refrigerator

technical field

The present invention relates to a refrigerator, and more particularly to a refrigerator that removes frost adhering to an evaporator with a hot gaseous refrigerant.

Background technique

The evaporator that constitutes a part of the cooling circuit of the refrigerator has frost formed due to the cooling of the surrounding water vapor, and there is a risk of lowering the cooling performance. In order to cope with this situation, a hot gas bypass pipe connected to the upstream side of the evaporator is provided downstream of the compressor constituting a part of the cooling circuit, by means of which the high temperature gas temporarily flows through the evaporator so that the evaporator becomes A hot gas defrosting process in which heat is used to defrost is known (for example, refer to Patent Document 1). In Patent Document 1, the evaporator is heated by directly supplying the hot gaseous refrigerant discharged from the compressor to the inlet of the heat exchange pipe of the evaporator to perform defrosting treatment.

(Prior art literature)

(patent documents)

Patent Document 1: Japanese Patent Application Laid-Open No. 2018-54287

However, in the hot gas defrosting process described in Patent Document 1, since the temperature difference between the supplied hot gas refrigerant and the heat exchange pipe is large, condensation of the refrigerant occurs in the heat exchange pipe. The heat exchange pipe of the evaporator usually meanders from the inlet on the upper side of the evaporator to the lower side, and then returns to the upper side to reach the outlet. As a result, the condensed refrigerant accumulates on the lower side of the evaporator, and the temperature rise on the outlet side of the heat exchange tube becomes slower, so that the defrosting process may take longer.

In view of this, it is necessary to improve existing refrigerators to solve the above problems.

Contents of the invention

An object of the present invention is to provide a refrigerator capable of efficiently defrosting an evaporator in a short time using a hot gaseous refrigerant.

To achieve the above object, the present invention provides a refrigerator comprising:

cold room;

a cooling circuit, in which a cooling cycle is implemented in which the refrigerant flows sequentially through the compressor, the condenser, the evaporator and returns to said compressor again;

a hot gas bypass directly connecting the outlet side of the compressor with the inlet side of the evaporator; and

a fan, which is used to move the air in the refrigerator;

It is characterized in that the gas is circulated by the fan as follows: the gas passing through the evaporator flows into the refrigerating chamber from bottom to top, and the gas flowing in the refrigerating chamber returns to the lower side of the evaporator again,

The inlet and outlet of the heat exchange pipes of the evaporator for refrigerant flow are arranged on the upper side of the evaporator,

A first defrosting process is performed in which the refrigerant discharged from the compressor is supplied to the inlet of the heat exchange pipe through the hot gas bypass pipe, and at the same time the refrigerant flowing in the refrigerating chamber is also defrosted. The gas is supplied to the underside of the evaporator for the gas defrosting process.

Thus, when the hot gas defrosting process is performed with the hot gas refrigerant, the temperature of the heat exchange pipe of the evaporator is low, so there is a risk that the refrigerant condenses and accumulates on the lower side of the evaporator. However, according to the present invention, by supplying the temperature-increased gas flowing in the refrigerating room to the lower side of the evaporator, it is possible to warm the lower side of the evaporator, suppress the condensation of the refrigerant, and prevent the refrigerant from accumulating on the lower side of the evaporator. . Accordingly, it is possible to provide a refrigerator capable of efficiently defrosting the evaporator in a short time using a hot gaseous refrigerant.

Further, after the start of the first defrosting procedure, when a specified time elapses or when the temperature of the gas flowing in the refrigerating chamber reaches a specified temperature, a second defrosting procedure is implemented, in which the Gas defrosting treatment, and only the hot gas defrosting treatment.

In this way, as the gas defrosting process using the gas flowing in the refrigerator compartment continues, the temperature of the circulating gas rises, and there is a risk that the temperature in the refrigerator compartment rises. According to the present invention, when a predetermined time elapses or when the temperature of the gas flowing in the refrigerator reaches a predetermined temperature, the gas defrosting process is stopped, and only the hot gas defrosting process is performed. In this way, the defrosting process of the evaporator can be efficiently performed while suppressing the temperature rise of the refrigerator compartment.

Further, the refrigerator also includes:

A switching valve that switches between an open state in which 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 closed state , the refrigerant discharged from the compressor flows to the side of the condenser to perform normal operations;

The damper of the refrigerating room is switched between an open state in which gas flows from the cooling flow path provided with the evaporator to the refrigerating room, and a closed state in which gas does not flow from the cooling channel provided with the evaporator. The cooling flow path flows to the refrigerator compartment; and

a control section for controlling the compressor, the fan, the switching valve, and the refrigerating compartment damper;

The control part starts the first defrosting process by opening the switching valve while the compressor is turned on, and simultaneously opening the refrigerating compartment damper while the fan is turned on, When a predetermined time elapses or when a temperature of air flowing in the refrigerating chamber reaches a preset temperature, the first defrosting procedure is switched to the second defrosting procedure by closing at least the refrigerating chamber damper.

In this way, the first defrosting course and the second defrosting course can be reliably performed by controlling the compressor, the fan, the switching valve, and the refrigerator compartment damper by the controller.

Further, the control unit switches from the first defrosting program to the second defrosting program based on timing data of a timer or measurement data of a temperature sensor provided in the refrigerator compartment.

In this way, based on the data of the timer or the temperature sensor, switching from the first defrosting routine to the second defrosting routine can be performed at an accurate timing.

Further, the refrigerator further includes a freezer compartment and a freezer damper switchable between an open state and a closed state. In the open state, gas flows from the cooling flow path to the freezer compartment. In the state, the gas does not flow from the cooling channel to the freezing compartment; the control unit maintains the freezing compartment damper in a closed state during the execution of the first defrosting process and the second defrosting process.

In this manner, by maintaining the freezer door in the closed state, it is possible to reliably suppress a rise in the temperature of the freezer compartment while performing the first defrosting course or the second defrosting course.

The beneficial effects of the present invention are: the refrigerator of the present invention can efficiently defrost the evaporator in a short time by using the hot gas refrigerant.

Description of drawings

Fig. 1 is a side sectional view of the refrigerator of the present invention.

Fig. 2 is a block diagram showing the configuration of the cooling circuit of the refrigerator of the present invention.

Fig. 3 is a diagram of piping near an evaporator in the refrigerator of the present invention.

Fig. 4 is a block diagram of a control system associated with defrosting of the refrigerator of the present invention.

Fig. 5A is a control timing chart when hot gas defrosting processing and gas defrosting processing are performed.

Fig. 5B is a control time chart when only the hot gas defrosting process is performed.

detailed description

In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Hereinafter, the refrigerator 10 of the present invention will be described in detail with reference to the drawings. In the description of this embodiment, in principle, the same reference numerals are used for the same components, and overlapping descriptions are omitted. In addition, in the following description, each direction of up, down, front, back, left, and right is used for description, but left and right are left and right when refrigerator 10 is seen from the front.

Fig. 1 is a side sectional view of a refrigerator 1 of the present invention. First, the outline of the refrigerator 1 of the present invention will be described with reference to FIG. 1 .

Refrigerator 1 has casing 2 , and the front portion of casing 2 includes an upper door 3 and a lower door 4 rotatably mounted in a state placed on a horizontal floor. The inside of the housing 2 (hereinafter referred to as “inside the refrigerator”) is provided with a freezer compartment 6 and a refrigerator compartment 7 . A heat insulating material is arranged between the inner surface of the shell 2 and the outer surfaces of the freezing chamber 6 and the refrigerating chamber 7 .

As shown in FIG. 1 , behind the freezer compartment 6 and the refrigerator compartment 7 , there is provided a cooling flow path 10 consisting of a lower cooling flow path 10A and an upper cooling flow path 10B separated by

partition plates

11A, 11B, respectively. The cooling flow path 10 (to be precise, the lower side cooling flow path 10A) is provided with an evaporator (evaporator) 24 . The evaporator 24 constitutes a part of the cooling circuit 20 of the refrigerator 1 as will be described later. A fan 12 is provided above the evaporator 24 in the cooling flow path 10 . The air in the refrigerator can be circulated by the fan 12 , and the air cooled by the evaporator 24 can be supplied to the freezer compartment 6 or the refrigerator compartment 7 from the cooling flow path 10 .

A freezer compartment damper 13 is provided at an upper opening of the lower partition plate 11A. In the open state of freezer compartment damper 13 , the gas passing through evaporator 24 flows from cooling flow path 10 (lower side cooling flow path 10A) to freezer compartment 6 . On the other hand, in the closed state of freezer compartment damper 13 , the gas passing through evaporator 24 is prevented from flowing from cooling flow path 10 (lower side cooling flow path 10A) to freezer compartment 6 . As shown in FIG. 1 , the freezer door 13 is in a closed state.

When the freezer door 13 is opened, the fan 12 is driven so that the air flowing into the freezer 6 from the cooling flow path 10 (lower cooling flow path 10A) circulates in the freezer 6 and flows from the bottom of the lower partition plate 11A. The side opening returns to the cooling flow path 10 (lower side cooling flow path 10A). In this way, the gas is cooled again by passing through the evaporator 24 to repeat the same flow cycle. In this way, the stored goods in the freezer compartment 6 can be cooled.

However, it is not limited to the case where the freezer compartment damper 13 is used to switch whether or not the gas flows into the freezer compartment 6 . For example, a movable fan cover that covers the outside of the fan 12 may also be used. It can be made that: when the fan cover is opened, the gas discharged from the fan 12 flows into the freezer compartment 6, and when the fan cover is closed, the gas discharged from the fan 12 does not flow into the freezer compartment 6.

Further, a refrigerator compartment damper 14 is provided between the lower cooling flow path 10A and the upper cooling flow path 10B. With the refrigerator compartment damper 14 open, the gas passing through the evaporator 24 flows from the lower cooling flow path 10A to the upper cooling flow path 10B. Further, the 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 the respective openings provided at a plurality of height positions. On the other hand, in the closed state of the refrigerator compartment damper 14 , the gas passing through the evaporator 24 is prevented from flowing from the lower cooling flow path 10A to the upper cooling flow path 10B. As shown in FIG. 1 , the damper 14 of the refrigerator compartment is in an open state, and the gas flow at this time is shown by dotted arrows.

The fan 12 is driven, and when the refrigerating compartment damper 14 is opened, the gas flowing into the refrigerating compartment 7 from the cooling flow path 10 (upper side cooling flow path 10B) circulates in the refrigerating compartment 7 and flows into the lower opening of the refrigerating compartment 7. The inlet 15A of the return flow path 15. While the gas passing through the evaporator 24 circulates in the refrigerator compartment 7, the stored items in the freezer compartment 6 can be cooled.

The return flow path 15 is provided so that the gas circulating in the refrigerator compartment 7 flows into the lower side of the cooling flow path 10 (lower side cooling flow path 10A) instead of flowing in the freezer compartment 6 . The return flow path 15 is provided spaced apart from the cooling flow path 10 . The gas that flows into refrigerator compartment 7 from cooling channel 10 (upper cooling channel 10B) and circulates in refrigerator compartment 7 flows into return channel 15 from inlet 15A. Then, the inflowing gas flows in 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 provided in the cooling channel 10 (the lower cooling channel 10A). In this way, the gas is cooled again by passing through the evaporator 24 to repeat the same flow cycle. In this way, the goods stored in the refrigerator compartment 7 can be cooled.

In the rear lower part of the casing 2, there is provided a machine room 40 in which a compressor 21, a condenser 22, an evaporating dish (not shown) and the like are provided.

Fig. 2 is a block diagram showing the configuration of the cooling circuit 20 of the refrigerator 1 according to the present invention. Next, an outline of the cooling circuit 20 will be described with reference to FIG. 2 .

The cooling circuit 20 includes a compressor (compressor) 21 , a condenser (condenser) 22 , a capillary tube 23 and an evaporator 24 . The components of the cooling circuit 20 are fluidly connected in the above-mentioned order by pipes to be described later, and form a first refrigerant flow path through which the refrigerant circulates in the cooling circuit 20 . The arrows described in FIG. 2 indicate the flow direction of the refrigerant.

The compressor 21 compresses the refrigerant in a gaseous state to bring it into a state of high temperature and high pressure. The compressed refrigerant is sent to the condenser 22 through the pipe 25 . The piping 25 is provided with a switching valve (three-way valve) 31 to be described later, and the piping 25 is divided into a piping 25a and a piping 25b. The compressor 21 includes an inverter, and the amount of refrigerant discharged by the compressor per unit time can be adjusted by changing the rotation speed, thereby controlling the cooling capacity of the cooling circuit 20 . The condenser 22 releases the heat of the refrigerant compressed by the compressor 21 to condense the refrigerant. The condensed refrigerant is sent to the capillary tube 23 through the pipe 26 .

The capillary 23 reduces the pressure of the refrigerant condensed by the condenser 22 to expand it, thereby lowering the temperature. The expanded refrigerant is sent to heat exchange pipe 24A of evaporator 24 through pipe 27 . In the heat exchange tube 24A that promotes heat exchange with fins, the refrigerant decompressed by the capillary tube 23 evaporates and absorbs heat. The evaporated refrigerant in a gaseous state is sent to the compressor 21 through the suction pipe 28 and compressed again. The cooling circuit 20 operates in this way. According to the present embodiment, the capillary 23 is connected to the condenser 22 and the evaporator 24 through the piping 26 and the piping 27 , but the

piping

26 , 27 may also be included in the capillary 23 .

A suction pipe 28 for flowing the refrigerant from the evaporator 24 to the compressor 21 is provided close to at least part of the capillary tube 23 so as to enable heat exchange with the capillary tube 23 . The area 29 enclosed by the dotted line in FIG. 2 shows the outline of this heat exchange part.

When the evaporator 24 exchanges heat with the gas flowing in the refrigerator 1, it may be frosted by water vapor contained in the gas. Then, in order to defrost the evaporator 24, in the refrigerator 1 of this embodiment, the hot gas defrosting process and the gas defrosting process described later are performed. In the hot gas defrosting process, a hot gas refrigerant compressed by the compressor 21 is used. To this end, the cooling circuit 20 comprises a hot gas bypass 30 connected to a pipe 25 connecting downstream of the compressor 21 and upstream of the condenser 22 . The connection part is provided with a switching valve (three-way valve) 31, which can change the refrigerant delivered from the compressor 21 through the piping 25a, and make it flow to the condenser 22 (that is, the piping 25b) or the hot gas side. Either side of the through pipe 30. In this way, it can be controlled 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 connecting the downstream of the capillary 23 and the upstream of the evaporator 24 .

Unlike the first refrigerant flow path in which the refrigerant flows through the path of compressor 21-pipe 25-condenser 22-pipe 26-capillary 23-pipe 27-evaporator 24 in the above-mentioned cooling flow path, the hot gas bypass pipe 30 constitutes a The refrigerant flows through the second refrigerant flow path of the compressor 21 -pipe 25 -hot gas bypass pipe 30 -pipe 27 -evaporator 24 . According to the present embodiment, the upstream side end portion of the hot gas bypass pipe 30 is connected to the piping 25 , however, it is not limited to this configuration. For example, the upstream end of the hot gas bypass pipe 30 may be connected to the pipe 26 connecting the downstream of the condenser 22 and the upstream of the capillary 23 .

The switching valve (three-way valve) 31 is opened and closed by a control unit 100 (see FIG. 4 ). The controller 100 controls the switching valve (three-way valve) 31 so that the refrigerant discharged from the compressor 21 through the pipe 25a flows to the condenser 22 (that is, the pipe 25b) during normal operation, and flows to the condenser 22 (that is, the pipe 25b) during hot gas defrosting processing described later. Hot gas bypass pipe 30.

In this specification, the state in which the refrigerator 1 operates normally (that is, the state in which it operates to cool the inside of the refrigerator or to maintain the temperature in the refrigerator) is referred to as "normal operation". In addition, the state in which the refrigerator 1 is operated to defrost the evaporator 24 (that is, the state in which the switching valve (three-way valve) 31 is opened so that the refrigerant flows from the switching valve (three-way valve) 31 to the hot gas bypass pipe 30, and The operation of the refrigerator to cause the hot gas to flow to the evaporator 24) is called "hot gas defrosting process".

Fig. 3 is a diagram of piping near the evaporator 24 in the refrigerator 1 of the present invention. As shown in FIG. 3 , the capillary tube 23 is connected to an inlet 24A1 of the heat exchange pipe 24A of the evaporator 24 through a pipe 27 . An outlet 24A2 of the heat exchange pipe 24A of the evaporator 24 is connected to a suction pipe 28 . Both the inlet 24A1 and the outlet 24A2 of the heat exchange pipe 24A of the evaporator 24 are provided on the upper side of the evaporator 24 .

In addition, the pipe 27 is connected to the hot gas bypass pipe 30 on the upstream side of the connection with the evaporator 24 . In FIG. 3 , the penetration portion 32 is shown upstream of the pipe 27 (or the capillary 23 ) and the hot gas bypass pipe 30 . The piping 27 (or the capillary tube 23 ) and the hot gas bypass pipe 30 are provided so as to communicate with the lower area of the case 2 through the penetration portion 32 .

The hot gas bypass pipe 30 is not used during normal operation of the refrigerator 1 . However, during this normal operation, at least a part 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 23 to the evaporator 24 may be different from the normal flow of the refrigerant. The opposite direction flows into the hot gas bypass pipe 30 .

A specified amount of refrigerant is injected into the cooling circuit 20 so that specified cooling performance is satisfied. As a result, when the refrigerant flows backward into the hot gas bypass pipe 30 , the amount of refrigerant that can be effective during the normal operation of the cooling circuit 20 decreases, and the specified cooling performance may not be satisfied. In addition, due to the reduction in cooling performance, the operation rate of the cooling circuit 20 for cooling the evaporator 24 increases (for example, the amount of refrigerant discharged from the compressor 21 increases, etc.), and thus the amount of power consumed may increase.

Then, the hot gas bypass pipe 30 (as shown in FIG. 3 ) of the refrigerator 1 of the present embodiment has a connecting portion 30 a configured to connect the hot gas bypass pipe 30 and the piping 27 ( or the capillary 23) (hereinafter referred to as the first pipe as appropriate). Point A represents a joint point between the hot gas bypass pipe 30 and the first pipe 27 . Since the refrigerant flowing toward the first pipe 27 downstream of the capillary 23 basically flows in a liquid state, it tends to flow downward in the vertical direction due to the force of gravity. As a result, the flow of the refrigerant to the hot gas bypass pipe 30 can be suppressed due to the piping connection from the vertical direction upward like the connecting portion 30a of the hot gas bypass pipe 30 of the present embodiment.

In addition, as shown in FIG. 3 , the hot gas bypass pipe 30 may be provided with a refrigerant backflow preventing portion 30b. The refrigerant backflow preventing portion 30b is placed in a part of the hot gas bypass pipe 30, and the upstream side of the part stands up substantially vertically with respect to the downstream side, so that the upstream side of the hot gas bypass pipe 30 is perpendicular to the downstream side. It is located on the upper side, and on the upstream side of this part, it is formed so as to descend downward in the vertical direction.

Since the position in the vertical direction rises first, then falls, and the lower side is opened in a substantially U-shape, even if the liquid refrigerant flows into the hot gas bypass pipe 30, it is difficult for the refrigerant to pass through the vertical pipe on the downstream side of the refrigerant backflow preventing portion 30b. The hot gas further flows into the upstream side of the hot gas bypass pipe 30 from the raised portion. Accordingly, it is possible to suppress the flow of the refrigerant upstream of the refrigerant backflow preventing portion 30b, and suppress the amount of refrigerant flowing into the hot gas bypass pipe 30 to a certain amount or less. In addition, instead of the refrigerant backflow preventing portion 30b, a check valve may be provided at the piping 30c for connecting to the connection portion 30a of the hot gas bypass pipe 30, so that the refrigerant can be suppressed from flowing into the upstream side.

In this way, it is possible to suppress a reduction in the cooling performance of the cooling circuit 20 and to suppress an increase in the amount of power consumption. In addition, it is also possible to design the refrigerant filled in the cooling circuit 20 in consideration of the reduction of the refrigerant (that is, in consideration of the possible reduction of the refrigerant in the volume portion from the above-mentioned point A to the refrigerant backflow prevention part 30b). The total amount of refrigerant and cooling control.

The refrigerant backflow preventing portion 30b is located on the lower rear side of the casing 2, and is provided at a portion that is thermally insulated from the outside air by a foam heat insulating material or the like. However, the piping in the vicinity of the evaporator 24 is not limited to the above, as long as at least the inlet 24A1 and the outlet 24A2 of the heat exchange pipe 24A of the evaporator 24 are provided on the upper side of the evaporator 24 and the hot gas bypass pipe 30 communicates with the heat exchange pipe 24A. Inlet 24A1, any other piping arrangements are also conceivable.

As described above, the hot gas 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 , so that the hot gas defrosting process of the evaporator 24 can be performed. The heat exchange pipe 24A is heated by the hot gaseous refrigerant flowing through the heat exchange pipe 24A, and the fins are also heated by heat conduction. This melts the frost attached to the evaporator 24, and the melted liquid falls. The falling liquid is received by a receiving pan provided on the lower side of the evaporator 24 , and flows into the evaporating pan in the machine room 40 through the draft tube. The liquid flowing into the evaporating pan evaporates into the atmosphere.

As shown in FIG. 3 , the heat exchange pipe 24A of the evaporator 24 meanders from the inlet 24A1 located on the upper side of the evaporator 24 to the lower side, and then meanders from the lowest point to the upper side again, and reaches the evaporator. The outlet 24A2 on the upper side of the device 24. In FIG. 3 , the heat exchange pipe 24AA is shown in an omitted manner meandering back to the upper side. That is, both the inlet 24A1 and the outlet 24A2 of the heat exchange pipe 24A are located on the upper side of the evaporator 24 .

In the case of only hot gas defrosting treatment, since the temperature difference between the hot gas refrigerant and the heat exchange pipe 24A of the evaporator 24 is large, the refrigerant condenses in the heat exchange pipe 24A, and the condensed refrigerant accumulates in the evaporator. The underside of the device 24. As a result, the temperature rise on the outlet side of the heat exchange pipe 24A becomes slower, and thus the defrosting process may take longer. Therefore, in the refrigerator 1 of the present embodiment, in addition to the hot gas defrosting process, the gas defrosting process described below is also performed.

As described above, when the refrigerator compartment damper 14 is opened, the fan 12 is driven so that the gas passing through the evaporator 24 provided in the cooling flow path 10 (lower side cooling flow path 10A) is cooled from the cooling flow path 10 (upper side cooling flow path 10A). Flow path 10B) flows into refrigerator compartment 7 , circulates in refrigerator compartment 7 , and returns to the lower side of evaporator 24 provided in cooling flow path 10 (lower side cooling flow path 10A) through return flow path 15 . At this time, since the gas circulating in the refrigerator compartment 7 absorbs heat from the items in the refrigerator compartment, etc., when the gas flows into the return flow path 15, the temperature of the gas rises. When the temperature-raised gas passes through the evaporator 24 again, the evaporator 24 can be warmed.

In particular, since the gas whose temperature has risen passes through the lower region of the heat exchange pipe 24A, it is possible to effectively suppress the problem that the lower gas condenses and accumulates. In this way, efficient defrosting can be performed in the entire evaporator 24 including the outlet 24A2 side of the heat exchange pipe 24A.

FIG. 4 is a block diagram showing a control system 100 associated with defrosting of the refrigerator 1 according to one embodiment of the present invention. Next, a control system 100 for performing the defrosting process as described above 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 may receive measurement data (signals) from the temperature sensor 50 (refer to FIG. 1 ) provided in the refrigerator compartment 50 . In addition, the control system 100 may receive timing data (signal) from the timer 51 . Further, the control system 100 may transmit control signals to the compressor 21 , the fan 12 , the freezer damper 13 , the refrigerator compartment damper 14 and the switching valve (three-way valve) 31 .

Fig. 5A is a control timing chart when hot gas defrosting processing and gas defrosting processing are performed. In the refrigerator 1 of the present embodiment, the first defrosting program is performed by the control system 100, wherein the hot gas defrosting process and the gas defrosting process are performed; and the second defrosting process is performed, wherein the gas defrosting process is stopped, and only the hot gas The defrosting process continues.

In normal operation, the on-off of the compressor 21 and the fan 12 and the opening and closing of the freezer compartment damper 13 and the refrigerating compartment damper 14 are controlled correspondingly according to the temperature condition in the refrigerator. In the case of cooling the freezer compartment 6, by opening the freezer compartment damper 13 in a state where the compressor 21 and the fan 12 are turned on, the gas passing through the evaporator 24 can be supplied into the freezer compartment 6 to cool it. In the case of cooling the refrigerator compartment 7, by opening the refrigerator compartment damper 14 in a state where the compressor 21 and the fan 12 are turned on, the gas passing through the evaporator 24 can be supplied into the refrigerator compartment 7 to cool it. Under the state that compressor 21 and fan 12 are switched on, by opening freezer compartment damper 13 and refrigerating compartment damper 14, the gas that can pass through evaporator 24 can be supplied in freezing compartment 6 and refrigerating compartment 7 so that these two compartments are cooled. cool down. In any case, during normal operation, the switching valve (three-way valve) 31 is kept closed.

In the case of performing defrosting, first, a first defrosting process is performed in which both the hot gas defrosting process and the gas defrosting process are performed. Specifically, by opening the switching valve (three-way valve) 31 in the state where the compressor 21 is turned on, or turning on the compressor 21 after opening the switching valve (three-way valve) 31, the hot gas bypass pipe 31 is turned on. The hot gas refrigerant is supplied to the evaporator 24 for the hot gas defrosting process.

At the same time, a gas defrosting process is performed in which the refrigerating compartment damper 14 is opened with the fan 12 turned on, the gas is supplied from the cooling flow path 10 to the refrigerating compartment 7, and the gas is circulated in the refrigerating compartment 7 to raise the temperature. The gas is supplied to the lower side of the evaporator 24. In this way, the first defrosting process that performs both the hot gas defrosting process and the gas defrosting process starts. At this time, the freezer compartment damper 13 is always closed, which can prevent the gas with temperature rise from flowing into the freezer compartment 6 .

As the gas defrosting process continues, the temperature of the gas circulating in the refrigerator compartment 7 gradually rises, so the temperature in the refrigerator compartment 7 may rise too high. Therefore, after a certain time elapses after the start of the first defrosting process, a second defrosting process is performed in which the gas defrosting process is stopped and only the hot gas defrosting process is continued. In this case, the freezer compartment damper 13 is also always closed, which can prevent the temperature-rising gas from flowing into the freezer compartment 6 .

If the movable fan cover covering the outside of the fan 12 is used, the fan cover is always closed during the first defrosting process and the second defrosting process, thereby preventing the temperature-rising air from flowing into the freezing chamber 6 .

The timing of switching from the first defrosting program to the second defrosting program, for example, uses the timing data according to the timer 51. After a predetermined time has elapsed, the fan 12 can be cut off and the refrigerator compartment damper 14 can be closed to stop the gas defrosting process. control processing. In addition, when the temperature measured by the temperature sensor 50 provided in the refrigerator compartment 7 reaches a preset temperature, the control process of turning off the fan 12 and closing the refrigerator compartment damper 14 to stop the gas defrosting process may also be performed.

Further, the information from both the timer 51 and the temperature sensor 50 can be used to determine the timing of switching from the first defrosting procedure to the second defrosting procedure. In the second defrosting program, if there is a store room into which gas other than the freezer compartment 6 and the refrigerator compartment 7 may flow, the refrigerator compartment damper 14 may be closed, but the fan 12 may continue to be driven.

After the start of the second defrosting process of only the hot gas defrosting process, the second defrosting process may be ended when a predetermined time point elapses based on the timing message from the timer 51 . Specifically, the open switching valve (three-way valve) 31 is closed to stop the hot gas defrosting process, and the cooling circuit 20 returns to the normal operation mode. Through the first and second defrosting procedures described above, the temperature inside the refrigerator compartment 7 can be prevented from rising excessively, and at the same time, the evaporator 24 can be effectively defrosted.

When the cooling circuit 20 returns to the normal operation mode and the evaporator 24 is cooled again, the freezer compartment 6 or the refrigerator compartment 7 can be cooled by turning off the fan 12 and opening the freezer compartment damper 13 or the refrigerator compartment damper 14 .

In FIG. 1 , the temperature sensor 50 is disposed on the upper side of the refrigerating chamber 7 , however, it is not limited thereto, and the temperature sensor 50 may be disposed at any position in the refrigerating chamber 7 . In addition, a temperature sensor is provided in the cooling flow path 10, and the timing of switching from the first defrosting course to the second defrosting course can be determined based on temperature data from the temperature sensor.

Fig. 5B is a control time chart when only the hot gas defrosting process is performed. For reference, conventionally performed control when only the hot gas defrosting process 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, the switching valve (three-way valve) 31 is closed to end the hot gas defrosting process.

In the above-mentioned embodiment, the refrigerator compartment 7 is 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, but the present invention is not limited thereto. For example, when the refrigerator compartment 7 is located at the position where the freezer compartment 6 in FIG. 1 is installed, the gas flowing in the refrigerator compartment 7 can flow into the lower side of the evaporator 24 as it is.

In the above-described embodiments, the case where a three-way valve is used as the switching valve 31 is shown, however, it is not limited thereto. For example, a T-shaped pipe is installed at the branch, and an on-off valve is provided on the branch side (the side of the hot gas bypass pipe 30 ), so that the same function as that of the three-way valve can also be realized. In this case, the on-off valve functions as the switching valve 31 .

As mentioned above, the refrigerator of the present invention includes: a refrigerating chamber 7; a cooling circuit 20, in which a cooling cycle is implemented, and in the cooling cycle, the refrigerant flows through the compressor 21, the condenser 22, the evaporator 24 and returns to the compressor 21 again ; hot gas bypass pipe 30, which directly connects the outlet side of compressor 21 and the inlet side of evaporator 24; and fan 12, which is used to make the gas flow in the refrigerator; the gas is circulated as follows by fan 12: passing from bottom to top The gas of the evaporator 24 flows into the refrigerating room 7, and the gas flowing in the refrigerating room 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 for refrigerant flow are arranged in the evaporator 24; implement the first defrosting process, wherein the refrigerant discharged from the compressor 21 passes through the hot gas bypass pipe 30 and is supplied to the inlet 24A1 of the heat exchange pipe 24A. The gas flowing inside 7 is supplied to the lower side of the evaporator 24 for the gas defrosting process.

When only the hot gas defrosting process is performed, there is a risk that the refrigerant condenses and accumulates on the lower side of the evaporator. The lower side warms the lower side of the evaporator 24 , suppresses condensation of the refrigerant, and prevents the refrigerant from accumulating on the lower side of the evaporator 24 . Accordingly, it is possible to provide a refrigerator capable of efficiently defrosting the evaporator in a short time using a hot gaseous refrigerant.

Further, the refrigerator 1 of this embodiment implements the second defrosting procedure after the first defrosting procedure starts, when a predetermined time elapses or when the temperature of the gas flowing in the refrigerating chamber 7 reaches a preset temperature, the second defrosting procedure is stopped. Gas defrost treatment, and hot gas defrost treatment only.

As the defrosting process using the gas flowing in the refrigerator compartment 7 continues, the temperature of the circulating gas rises, and there is a risk that the temperature inside the refrigerator compartment 7 rises. However, when a predetermined time elapses or when the temperature of the gas flowing in the refrigerator compartment 7 reaches a predetermined temperature, the gas defrosting process is stopped, and only the hot gas defrosting process is performed. In this way, the defrosting process of the evaporator 24 can be efficiently performed while suppressing the temperature rise of the refrigerator compartment 7 .

The refrigerator 1 of the present embodiment also includes: a switching valve 31 that switches between an open state and a closed state. In the open state, the refrigerant discharged from the compressor 21 flows to the hot gas bypass pipe 30 side to implement hot gas defrosting treatment. In the closed state, the refrigerant discharged from the compressor 21 flows to the side of the condenser 22 to implement normal operation; the refrigerating room damper 14 switched between the open state and the closed state, in the open state, the gas is cooled from the evaporator 24. The flow path 10 flows to the refrigerating chamber 7, and in the closed state, the gas does not flow from the cooling flow path 10 to the refrigerating chamber 7; and the control unit 100 is used to control the compressor 21, the fan 12, the switching valve 31 and the refrigerating chamber damper 14; The control unit 100 starts the first defrosting process in the following manner: the switching valve 31 is opened while the compressor 21 is turned on, and the refrigerating compartment damper 14 is opened while the fan 12 is turned on. When the temperature of the gas flowing in the refrigerating chamber 7 reaches a preset temperature, at least the refrigerating chamber damper 14 is closed to switch from the first defrosting program to the second defrosting program.

In this way, by controlling the compressor 21, the fan 12, the switching valve 31, and the refrigerating compartment damper 14 by the control unit 100, the first defrosting course and the second defrosting course can be reliably performed.

In addition, in the refrigerator 1 of the present embodiment, the control unit 100 performs the defrosting process from the first defrosting process to the second defrosting process based on the timing data of the timer 51 or the measurement data of the temperature sensor 50 provided in the refrigerator compartment 7. Therefore, the conversion from the first defrosting program to the second defrosting program can be performed at an accurate timing.

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, the gas flows from the cooling flow path 10 to the freezer compartment 6. In the process, the gas does not flow from the cooling channel 10 to the freezing compartment 6; the control unit 100 maintains the freezing compartment damper 13 in a closed state during the implementation of the first defrosting procedure and the second defrosting procedure.

In this way, the temperature rise of freezer compartment 6 can be reliably suppressed while the first defrosting course and the second defrosting course are executed.

The above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced. Without departing from the spirit and scope of the technical solution of the present invention.

Claims

A refrigerator comprising:

cold room;

a cooling circuit, in which a cooling cycle is implemented in which the refrigerant flows sequentially through the compressor, the condenser, the evaporator and returns to said compressor again;

a hot gas bypass directly connecting the outlet side of the compressor with the inlet side of the evaporator; and

a fan, which is used to move the air in the refrigerator;

It is characterized in that the gas is circulated by the fan as follows: the gas passing through the evaporator flows into the refrigerating chamber from bottom to top, and the gas flowing in the refrigerating chamber returns to the lower side of the evaporator again,

The inlet and outlet of the heat exchange pipes of the evaporator for refrigerant flow are arranged on the upper side of the evaporator,

A first defrosting process is performed in which the refrigerant discharged from the compressor is supplied to the inlet of the heat exchange pipe through the hot gas bypass pipe, and at the same time the refrigerant flowing in the refrigerating chamber is also defrosted. The gas is supplied to the underside of the evaporator for the gas defrosting process.
The refrigerator according to claim 1, wherein after the first defrosting procedure starts, when a predetermined time elapses or when the temperature of the gas flowing in the refrigerating chamber reaches a preset temperature, the second defrosting procedure is executed. A defrosting procedure, wherein the gas defrosting process is stopped, and only the hot gas defrosting process is performed.
The refrigerator according to claim 2, further comprising:

A switching valve that switches between an open state in which 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 closed state , the refrigerant discharged from the compressor flows to the side of the condenser to perform normal operations;

The damper of the refrigerating room is switched between an open state in which gas flows from the cooling flow path provided with the evaporator to the refrigerating room, and a closed state in which gas does not flow from the cooling channel provided with the evaporator. The cooling flow path flows to the refrigerator compartment; and

a control section for controlling the compressor, the fan, the switching valve, and the refrigerating compartment damper;

The control part starts the first defrosting process by opening the switching valve while the compressor is turned on, and simultaneously opening the refrigerating compartment damper while the fan is turned on, When a predetermined time elapses or when a temperature of air flowing in the refrigerating chamber reaches a preset temperature, the first defrosting procedure is switched to the second defrosting procedure by closing at least the refrigerating chamber damper.
The refrigerator according to claim 3, wherein the control unit performs the steps from the first defrosting process to the defrosting process based on counting data of a timer or measurement data of a temperature sensor installed in the refrigerator compartment. Switching to the second defrost program.
The refrigerator according to claim 3 or 4, characterized in that, the refrigerator further comprises a freezer compartment and a freezer compartment damper switchable between an open state and a closed state, and in the open state, the gas is cooled from the The flow path flows to the freezer compartment, and in the closed state, gas does not flow from the cooling flow path to the freezer compartment; the control unit is implementing the first defrosting procedure and the second defrosting procedure During this period, the freezer damper is maintained in a closed state.
The refrigerator according to claim 5, wherein the hot gas bypass pipe is provided with a refrigerant backflow prevention part, and the refrigerant backflow prevention part is provided in a part of the hot gas bypass pipe, and rises first, then descends, and the lower side is opened. U shape.
The refrigerator according to claim 6, wherein the refrigerant backflow prevention unit is located behind a lower side of a casing of the refrigerator, and is provided at a portion that is insulated from outside air by a foam heat insulating material or the like.
The refrigerator according to claim 1, wherein the heat exchange pipe meanders from the inlet on the upper side of the evaporator to the lower side, meanders left and right from the lowest point, and returns to the upper side to reach The outlet located on the upper side of the evaporator.
The refrigerator according to claim 8, wherein the cooling circuit further comprises a capillary tube, the capillary tube is connected to the inlet of the heat exchange pipe of the evaporator through a pipe, and a through pipe is provided upstream of the pipe and the hot gas bypass pipe. part, and the pipe and the hot gas bypass pipe communicate with the lower side of the outer casing of the refrigerator through the through part.
The refrigerator according to claim 5, wherein the cooling flow path is arranged behind the freezing chamber and the refrigerating chamber, and includes a lower cooling flow path and a lower cooling flow path separated by lower and upper partition plates, respectively. The upper cooling flow path, when the freezer door is opened, drives the fan, so that the gas flowing into the freezer from the lower cooling flow path circulates in the freezer chamber and returns to the cooling flow path from the lower opening of the lower partition plate .