WO2020166308A1

WO2020166308A1 - Defrosting device and refrigerator equipped with same

Info

Publication number: WO2020166308A1
Application number: PCT/JP2020/002659
Authority: WO
Inventors: 元康市場; 雅至中川
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2019-02-14
Filing date: 2020-01-27
Publication date: 2020-08-20
Also published as: JP2020133933A

Abstract

A defrosting device (200) comprises: a cooler (3) that has a refrigerant pipe (1) and a plurality of fins (2); an accumulator (4) that is connected to the refrigerant pipe (1) and stores a liquid refrigerant; and a defrosting heater (111) that is provided below the cooler (3). The defrosting device (200) also has an outlet pipe (5) that communicates with the portion of the refrigerant pipe (1) located at the bottom of the cooler (3). The accumulator (4) is connected to the refrigerant pipe (1) through the outlet pipe (5) and disposed above the cooler (3). The fins (2) have a coating.

Description

Defrosting device and refrigerator equipped with the same

The present disclosure relates to a defrosting device that improves the efficiency of defrosting in a cooler and a refrigerator including the defrosting device.

Conventionally, this type of defrosting device is a defrosting unit (hereinafter referred to as a defrosting heater) configured by an accumulator provided above a cooler and connected to a refrigerant pipe, and a glass tube heater provided below the cooler. Called). This cooler, the accumulator, the compressor, the condenser, and the cooler that has become low temperature by the operation of the cooling cycle configured by annularly connecting the depressurizing means, and the air, heat exchanges with the cool air. It is generated and cooled by a cooling device such as a refrigerator.

In such a defrosting device and a refrigerator equipped with such a defrosting device, air containing humidity generally becomes low temperature by exchanging heat with a cooler. Then, when the air drops to below the dew point temperature, condensed droplets are generated on the surface of the cooler.

Especially in a refrigerator, the refrigerant temperature is 0°C or lower, and the condensed droplets freeze to form frost. Therefore, the heat exchange area in the cooler is reduced, and as a result, the cooling performance of the cooler is reduced. Therefore, the defrost heater is energized at preset time intervals, and the heat from the defrost heater melts the frost adhering to the cooler during the cooling operation to defrost and suppress a decrease in cooling performance. ing. However, even after performing the defrosting operation to melt the frost adhering to the fins and the like, the molten water remains on the surfaces of the fins and the like. For this reason, if the melted water is recooled and frozen after restarting the cooling operation, the heat exchange area of the cooler is reduced and the cooling performance of the cooler is reduced.

Furthermore, the remaining melted water is repeatedly frozen and thawed each time a cooling operation and a defrosting operation are performed. Therefore, unnecessary power is consumed, and as a result, the power consumption of the refrigerator increases.

Therefore, in order to enhance the hydrophilicity of the cooling fin surface and enhance the drainage performance, a compound having an alkoxysilane structure, and a paint composed of a primary amine or a secondary amine are arranged on the fin surface of the cooler. It is considered to do so (for example, refer to Patent Document 1).

FIG. 3 is a sectional view showing a conventional refrigerator described in Patent Document 1.

As shown in FIG. 3, the refrigerator 300 has a refrigerating room 303 and a freezing room 304 which are vertically divided by a horizontal partition 302. A duct 305 is arranged behind the refrigerator compartment 303.

Further, the refrigerator 300 has a cooler 310. The cooler 310 includes a refrigerant pipe 314 that is bent in a meandering shape and has a plurality of stages, and a large number of fins 315 that are orthogonally attached to the refrigerant pipe 314. The fin 315 has a film for improving the hydrophilic property of the surface of the fin 315.

Further, an accumulator 316 connected to the refrigerant pipe 314 is arranged above the cooler 310.

During the cooling operation of the refrigerator 300, the compressor, the condenser, the pressure reducing means, the cooler 310, and the accumulator 316 are annularly connected to each other, and the cooler has a low temperature due to the operation of the refrigeration cycle. Heat exchange between the 310 and the accumulator 316 and the surrounding air generates low-temperature cold air. The cool air is supplied to the refrigerating chamber 303 and the freezing chamber 304 by the cooling fan 318.

When the refrigerator door and the freezer door are opened and closed, the outside air enters the refrigerator room 303 and the freezer room 304. Also, outside air enters the inside of the refrigerating chamber 303 and the freezing chamber 304 through the gap of a gasket (not shown) that seals the gap between each room and the door. Therefore, the air inside the refrigerator compartment 303 and the freezer compartment 304 has a relatively high humidity. The high-humidity air is sucked from the return air passage 308 and the slit and exchanges heat with the cooler 310 and the accumulator 316 having a low temperature, so that frost is attached to the cooler 310 and the accumulator 316.

After the cooling operation starts, frost is formed mainly on the lower part of the cooler 310, but over time, the upper part of the cooler 310 and the accumulator 316 are also frosted. When frost adheres to the cooler 310 and the accumulator 316, the heat exchange area between the cooler 310 and the accumulator 316 and the air decreases, and the cooling capacity decreases. Therefore, the defrost heater 311 provided below the cooler 310 is energized at preset time intervals to melt the frost adhering to the cooler 310 and the accumulator 316.

By the heat generated by the defrost heater 311, the frost attached to the bottom of the cooler 310 is first warmed from the outer surface. The melted water generated by warming the outer surface of the cooler 310 penetrates toward the root side (fin side) of frost, which is a fine structure, by a capillary phenomenon, and the entire frost is in a uniform water-containing state.

Also, since the frost that has become water-containing is warmed from the outer surface by the warm air rising inside the cooler chamber 307, the frost that has adhered to the cooler 310 gradually changes to molten water. When the frost adhering to the lower portion of the cooler 310 is melted and then heating is further continued, the liquid refrigerant in the refrigerant pipe 314 under the cooler 310 is evaporated.

The evaporated refrigerant passes through the inside of the refrigerant pipe 314 and moves upward. Here, since frost still adheres to the central part of the cooler 310, the evaporated refrigerant and the frost in the central part of the cooler 310 exchange heat via the refrigerant pipes 314 and the fins 315. At the time of heat exchange, the evaporated refrigerant releases heat to the frost, is condensed into a liquid refrigerant, and moves to the lower part of the cooler 310.

Also, frost absorbs heat and is melted. That is, during the defrosting operation, there are two actions, namely, heating from the outside such as radiation and convection, and a thermosiphon effect in which the refrigerant repeatedly evaporates and condenses to transport the heat to the upper part. The heat generated from the defrost heater 311 is transferred to the upper part of the cooler 310 by these two actions. As a result, the frost attached to the cooler 310 and the accumulator 316 is heated and melted.

Normally, on the aluminum fin surface with a contact angle of around 90°C, the molten water exists in the state of being separated into multiple water droplets. Therefore, the self-weight of the melted water is small, and the melted water remains on the fin surface even after completely melting. However, since the fin 315 has a hydrophilic film, the contact area between the water droplets of the molten water and the fin 315 is larger than that in the case where the fin 315 is not covered with the film. Therefore, adjacent droplets of the melted water on the surface of the fin 315 come into contact with each other, and the melted water becomes one large lump. As a result, the weight of one water drop becomes large and it easily falls. This enhances the drainage performance during the defrosting operation.

However, in the configuration described in Patent Document 1, since the defrost heater is arranged below the cooler 310, it takes time to completely melt the frost adhering to the surface of the accumulator 316 provided above. .. Therefore, the defrosting of the accumulator 316 causes the lower portion of the cooler 310 to be additionally warmed, which consumes extra energy. Further, since the fin 315 has a hydrophilic film that enhances the drainage property of the fin 315, the frost attached to the fin 315 is easily melted. Therefore, even though the frost attached to the fins 315 is melted, the accumulator 316 is likely to have a frost residual state in which frost remains.

JP, 2016-222787, A

In the present defrosting device, while maintaining the drainage characteristics of the fins during the defrosting operation, the heating of the accumulator is promoted to reduce the power consumption of the device and improve the reliability.

A defrosting device comprising a cooler having a refrigerant pipe and a plurality of fins, an accumulator connected to the refrigerant pipe and storing a liquid refrigerant, and a defrost heater provided below the cooler. The frost device further includes an outlet pipe that communicates with a portion of the refrigerant pipe located below the cooler. The accumulator is connected to the refrigerant pipe through the outlet pipe and is arranged above the cooler, and the plurality of fins have a film.

Thereby, the refrigerant evaporated in the lower refrigerant pipe of the cooler passes through the outlet pipe and reaches the accumulator, so while maintaining the characteristics of the film provided on the fins, during the defrosting operation, the frost attached to the accumulator Can be melted in a short time, and the entire accumulator can be heated uniformly.

FIG. 1 is a cross-sectional view in the center of the refrigerator when the refrigerator according to Embodiment 1 of the present disclosure is viewed from the right side. FIG. 2 is a sectional view taken along the line II-II of the refrigerator in FIG. FIG. 3 is a sectional view showing a conventional refrigerator.

A defrosting device according to an aspect of the present disclosure, a cooler having a refrigerant pipe and a plurality of fins, an accumulator connected to the refrigerant pipe to store a liquid refrigerant, and a defrost heater provided below the cooler. The defrosting device further includes: an outlet pipe that communicates with a portion of the refrigerant pipe located below the cooler. The accumulator is connected to the refrigerant pipe through the outlet pipe and is arranged above the cooler, and the plurality of fins have a film.

With this configuration, the refrigerant evaporated in the refrigerant pipe below the cooler passes through the outlet pipe and reaches the accumulator. Therefore, it is possible to melt the frost adhering to the accumulator in a short time during the defrosting operation while maintaining the characteristics of the film arranged on the fins. Further, since the entire accumulator can be heated uniformly, energy saving performance and reliability can be improved.

In the defrosting device according to another aspect of the present disclosure, the film may be composed of a hydrophilic film and a water-sliding film.

With such a configuration, the contact area between the molten water and the fins increases due to the hydrophilic properties of the film, and the self-weight of the molten water increases. In addition, the water-sliding property of the film makes it easier for the molten water to slip off. For this reason, it becomes possible to improve the drainage characteristic during the defrosting operation, and it is possible to further improve the energy saving performance.

In the defrosting device according to another aspect of the present disclosure, the film may be composed of a water repellent film and a water sliding film.

Due to such a structure, the contact area between the molten water and the fin is reduced due to the water-repellent property of the film, and the adhesive force between the molten water and the fin is reduced. In addition, the water-sliding property of the film makes it easier for the molten water to slip off. For this reason, it becomes possible to improve the drainage characteristic during the defrosting operation, and it is possible to further improve the energy saving performance.

In the defrosting device according to another aspect of the present disclosure, the film is formed of one of a hydrophilic film, a water-sliding film, and a water-repellent film.

With such a structure, when a hydrophilic film is used, the contact area between the molten water and the fins becomes large, and the molten water slides down due to contact with the adjacent molten water and an increase in the weight of the molten water. Easier to do. Further, when a water-sliding film is used, the molten water is likely to slip off due to the water-sliding property. Further, when a water-repellent coating is used, the contact area between the molten water and the fin is small, and the adhesive force between the molten water and the fin is reduced, so that the molten water is likely to slip off. Therefore, the coating can be made of a general-purpose material, the defrosting device can be constructed at a lower cost, and energy saving and reliability can be improved.

In the defrosting device according to another aspect of the present disclosure, the outlet pipe may be arranged on the bent end side of any one of the two bent ends of the refrigerant pipe.

With such a configuration, the outlet pipe is located outside the cooling air passage in the cooler, so the air passage resistance can be reduced. Therefore, the cooling capacity of the cooler can be increased, and the energy saving performance can be further improved.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to this embodiment.

(Embodiment 1)
[1-1. Constitution]
FIG. 1 is a cross-sectional view of the center of the refrigerator when the refrigerator is viewed from the right. FIG. 2 is a sectional view taken along the line II-II of the refrigerator in FIG.

As shown in FIGS. 1 and 2, the refrigerator 100 has a refrigerating room 103 and a freezing room 104 that are vertically divided by a horizontal partition 102. A duct 105 and a cooling chamber 109, which is provided on the rear surface of the freezing chamber and is divided into a cooler chamber 107 and a return air passage 108 by a vertical partition 106, are arranged behind the refrigerating chamber 103. The cooler 3 is arranged in the cooler chamber 107. The cooler 3 constitutes a part of a cold building cycle together with an accumulator 4 (see FIG. 2), a compressor (not shown), a condenser (not shown), and a pressure reducing means (not shown), which will be described later. ..

The front of the cooler 3 is covered with a freezer compartment cover 117. A cooling fan 118 is arranged above the freezer compartment cover 117. The refrigerator 100 also includes a refrigerating compartment door 119 provided in front of the refrigerating compartment 103 and a freezing compartment door 120 provided in front of the freezing compartment 104.

Further, a defrost heater 111 is arranged below the cooler 3. Between the cooler room 107 and the refrigerating room 103, the discharge port 112 which connects these is arrange|positioned. Further, between the refrigerating chamber 103 and the return air passage 108, a suction port 113 that connects them is arranged.

As shown in FIGS. 1 and 2, the cooler 3 is composed of a refrigerant pipe 1 and fins 2. The refrigerant pipe 1 has a shape bent in a plurality of steps so as to meander. The fins 2 are attached to the refrigerant pipe 1 in a state orthogonal to the refrigerant pipe 1. The fins 2 are arranged in parallel at a predetermined interval so that an air flow path is formed.

As shown in FIG. 2, the accumulator 4 is connected to the refrigerant pipe 1 located below the cooler 3 via the outlet pipe 5 of the cooler 3. The outlet pipe 5 is connected to the refrigerant pipe 1 located under the cooler 3 and extends vertically upward. The outlet pipe 5 is arranged on one of the two bent ends (the left and right ends of the refrigerant pipe 1 in FIG. 2) of the refrigerant pipe 1 (the right end side of the refrigerant pipe 1 in FIG. 2). ing. The accumulator 4 is arranged above the cooler 3. Moreover, the pipe length of the outlet pipe 5 is shorter than the pipe length of the refrigerant pipe 1.

The surface of the fin 2 of the cooler 3 is covered with the film 6. As the film, for example, a hydrophilic film made of acrylic resin can be used. The film is formed by immersing the fins 2 in a hydrophilic paint composed of a substance having an alkoxysilane structure and a primary amine, a secondary amine, or the like, or the hydrophilic paint is finned by a roll coater or the like. It may be formed by drying the fins 2 after being painted on. The coating may be a hydrophilic coating and a water-sliding coating. The coating may be a water repellent coating and a water sliding coating. Further, the film may be any of a hydrophilic film, a water-sliding film, and a water-repellent film.

In the present embodiment, the defrosting device 200 is configured to include the cooler 3, the accumulator 4, the defrosting heater 111, and the outlet pipe 5.

[1-2. Operation and action of refrigerator]
The operation and action of the defroster 200 configured as described above and the refrigerator 100 including the defroster 200 will be described below.

During the cooling operation of the refrigerator 100, the cooler 3 and the accumulator are operated by the operation of the refrigeration cycle configured by the compressor, the condenser, the pressure reducing means, the cooler 3, and the accumulator 4 connected in an annular shape. 4 becomes a low temperature state. Then, cool air generated by heat exchange between the cooler 3 and the accumulator 4 that have become low temperature and the air is supplied to the refrigerating chamber 103 and the freezing chamber 104 by the cooling fan 118.

Cold air flows from the outlet 112 through the duct 105 and is supplied to the refrigerating chamber 103. After cooling the refrigerating chamber 103, the cool air flows through the suction port 113, the return air passage 108, and is sucked into the cooler chamber 107 from the lower side surface of the cooler chamber 107.

Further, the cold air flows through the upper part of the freezer compartment cover 117 and is supplied to the freezer compartment 104. The air after cooling the freezing compartment 104 passes through a slit provided in the lower portion of the freezing compartment cover 117 (see FIG. 1) and is sucked into the cooler compartment 107. The sucked air is again heat-exchanged with the cooler 3 and the accumulator 4 to be cooled and supplied to the refrigerating room 103 and the freezing room 104.

At this time, the low-temperature low-pressure liquid refrigerant is passing through the refrigerant pipe 1. The refrigerant flows through the return air passage 108 and is sucked from the lower side surface of the cooler chamber 107, passes through the relatively high temperature air, and the slits provided in the lower portion of the freezer compartment cover 117 to pass through the cooler chamber 107. Air having a temperature higher than that of the cooler 3 sucked in is exchanged with heat via the refrigerant tubes 1 and the fins 2.

During heat exchange, the low-temperature low-pressure liquid refrigerant absorbs heat from the surroundings and evaporates, and the air passing through the surroundings releases the heat to a low temperature. The liquid refrigerant that has not completely evaporated in the cooler is stored in the accumulator 4, and in the accumulator 4 as well as the cooler 3, heat is exchanged with air to evaporate the refrigerant. For this reason, the accumulator 4 is also maintained at a low temperature comparable to that of the cooler 3.

When the refrigerator compartment door 119 and the freezer compartment door 120 are opened and closed, outside air enters the refrigerator compartment 103 and the freezer compartment 104. In addition, outside air enters the inside of the refrigerating chamber 103 and the freezing chamber 104 through the gap of a gasket (not shown) that seals the gap between each room and the door. Therefore, the air inside the refrigerator compartment 103 and the freezer compartment 104 has a relatively high humidity.

Frost is attached to the cooler 3 and the accumulator 4 by sucking the high-humidity air from the return air passage 108 and the slits and exchanging heat with the cooler 3 and the accumulator 4 having a low temperature.

After the cooling operation starts, frost is formed mainly on the lower part of the cooler 3, but over time, the upper part of the cooler 3 and the accumulator 4 are also frosted. When frost adheres to the cooler 3 and the accumulator 4, the heat exchange area between the cooler 3 and the accumulator 4 and the air decreases, and the cooling capacity decreases. Therefore, the defrosting heater 111 provided below the cooler 3 is energized at preset time intervals to melt the frost attached to the cooler 3 and the accumulator 4.

The warm air generated by the heat of the defrost heater 111 is higher in temperature than the air in the cooler chamber 107, so natural convection occurs in the cooler chamber 107. Therefore, starting from the vicinity of the defrost heater 111, the entire inside of the cooler chamber 107 is warmed. That is, the frost attached to the lower portion of the cooler 3 near the defrost heater 111 is first warmed from the outer surface and melted.

After the frost in the lower part of the cooler 3 is melted, if the heating is continued to melt the frost in the upper part of the cooler 3 and the accumulator 4, the liquid refrigerant in the refrigerant pipe 1 below the cooler 3 is evaporated. The evaporated refrigerant passes through the inside of the refrigerant pipe 1 and moves toward the upper side of the cooler 3. At this time, since frost still adheres to the central portion of the cooler 3, the evaporated refrigerant and the frost in the central portion of the cooler 3 exchange heat via the refrigerant pipes 1 and the fins 2.

During heat exchange, the evaporated refrigerant releases heat to frost, condenses into liquid refrigerant, and moves to the bottom of the cooler 3. In addition, frost absorbs heat and is melted. Therefore, when the refrigerant pipe 1 and the accumulator 4 in the upper part of the cooler 3 are connected, it takes time until the frost attached to the upper part of the cooler 3 and the accumulator 4 starts to melt. Therefore, in order to melt the frost attached to the upper part of the cooler 3 and the accumulator 4, the lower part of the cooler 3 and the lower part of the cooler chamber 107 are wastefully heated.

Therefore, in the present embodiment, the accumulator 4 is connected to the refrigerant pipe 1 located below the cooler 3 via the outlet pipe 5 of the cooler 3 (right side of the cooler in FIG. 2). The outlet pipe 5 is connected to the refrigerant pipe 1 located under the cooler 3 and extends vertically upward. The accumulator 4 is arranged above the cooler 3. Further, the surface of the fin 2 is covered with the film 6. As the film, for example, a hydrophilic film made of acrylic resin is used.

Thereby, the warm air generated by the heat of the defrosting heater 111 evaporates the liquid refrigerant in the refrigerant pipe 1 below the cooler 3. When the evaporated refrigerant passes through the inside of the refrigerant pipe 1 and moves upward, part of the evaporated refrigerant moves toward the outlet pipe 5 and moves upward inside the outlet pipe 5.

The refrigerant that has moved upward in the outlet pipe 5 exchanges heat with the frost adhering to the surface of the outlet pipe 5. As a result, the refrigerant releases heat to the frost and condenses to become a liquid refrigerant and moves to the lower portion of the cooler 3, and the frost absorbs heat from the refrigerant and is melted.

Then, the liquid refrigerant that has moved to the lower portion of the cooler 3 is warmed by the warm air generated by the heat of the defrost heater 111, and a series of phenomena that moves upward again is repeated until the frost is completely melted. ..

The outlet pipe 5 is shorter than the refrigerant pipe 1. Therefore, the evaporated refrigerant can reach the accumulator 4 in a short time. Therefore, it is possible to shorten the time until the frost in the accumulator 4 is completely melted.

Further, since the time until the frost in the accumulator 4 is melted is shortened, even if the fin 2 is covered with a hydrophilic film to improve the drainage performance of the fin 2 during the defrosting operation, the accumulator It is possible to prevent the frost remaining state in which the frost remains in No. 4.

As described above, in the present embodiment, the accumulator 4 is connected to the refrigerant pipe 1 located in the lower portion of the cooler 3 via the outlet pipe 5 of the cooler 3 (right side of the refrigerant pipe 1 in FIG. 2). Has been done. The outlet pipe 5 is connected to the refrigerant pipe 1 located under the cooler 3 and extends vertically upward. The accumulator 4 is arranged above the cooler 3.

With this, it is possible to prevent frost residue from the accumulator 4 and provide a refrigerator with high energy efficiency and high reliability.

Also, the fin 2 has a hydrophilic film. Therefore, the drainage performance during the defrosting operation can be improved.

In the present embodiment, the configuration in which the fin 2 has a film has been described, but the same effect can be obtained even when the film 6 is provided on the refrigerant pipe 1 or the accumulator 4 in addition to the fin 2.

The present disclosure can improve the drainage performance of the cooler during defrosting operation, reduce power consumption, and prevent frost residue from the accumulator. Therefore, the present invention can be applied to a cooling device such as a refrigerator of various types and sizes for home use and commercial use.

1 Refrigerant Pipe 2 Fin 3 Cooler 4 Accumulator 5 Outlet Pipe 6 Film 100 Refrigerator 102 Horizontal Partition 103 Refrigerator Room 104 Freezer Chamber 105 Duct 106 Vertical Partition 107 Cooler Room 108 Return Airway 109 Cooling Room 111 Defrost Heater 112 Discharge Port 113 Suction port 117 Freezer compartment cover 118 Cooling fan 200 Defrosting device

Claims

A cooler having a refrigerant pipe and a plurality of fins;
An accumulator connected to the refrigerant pipe and storing a liquid refrigerant,
A defrost heater provided below the cooler,
A defrosting device comprising:
The defrosting device further has an outlet pipe that communicates with a portion of the refrigerant pipe located below the cooler,
The accumulator is connected to the refrigerant pipe through the outlet pipe, and is arranged above the cooler,
The fins have a coating,
Defroster.
The outlet pipe extends vertically upward from the lower portion of the cooler,
The defrosting apparatus according to claim 1.
The pipe length of the outlet pipe is shorter than the pipe length of the refrigerant pipe,
The defrosting apparatus according to claim 1.
The film is a hydrophilic film and a water-sliding film,
The defrosting apparatus according to claim 1.
The film is a water-repellent film and a water-sliding film,
The defrosting apparatus according to claim 1.
The film is any one of a hydrophilic film, a water-sliding film, and a water-repellent film,
The defrosting apparatus according to claim 1.
The outlet pipe is arranged on the side of one of the two bent ends of the refrigerant pipe,
The defrosting device according to any one of claims 1 to 6.
A refrigerator provided with the defrosting device according to any one of claims 1 to 7.
The defrosting device is arranged on the back of the refrigerator inside the refrigerator,
The refrigerator according to claim 8.