WO2013088462A1

WO2013088462A1 - Refrigerator

Info

Publication number: WO2013088462A1
Application number: PCT/JP2011/006910
Authority: WO
Inventors: 雄亮田代; 浩史宮崎; 拓也児玉; 足達　威則; 活佳藤沢
Original assignee: 三菱電機株式会社
Priority date: 2011-12-12
Filing date: 2011-12-12
Publication date: 2013-06-20
Also published as: JP5847198B2; CN103917837B; SG11201401031PA; JPWO2013088462A1; CN103917837A

Abstract

A refrigerator having a refrigeration compartment and a freezer compartment, wherein the refrigerator is provided with: a cooler (15) for exchanging heat with a refrigerant to cool air from the refrigeration compartment and the freezer compartment, the cooler having a plurality of aligned fins and a heat transfer tube for conducting the refrigerant, and being configured so that a portion for conducting the air from the refrigeration compartment is positioned on the refrigerator exterior and has a wider fan pitch and/or smaller number of fins than a portion for conducting the air from the freezer compartment; a circulating fan (16) for circulating air between inside the compartments and the cooler; and a dedicated fan (17) for delivering the air that has been cooled by the cooler (15) to the refrigeration compartment.

Description

refrigerator

The present invention relates to a refrigerator. In particular, the present invention relates to a refrigerator that performs a cooling operation using a vapor compression refrigeration cycle.

Conventionally, in a refrigerator, for example, there is a refrigerator that configures a refrigerant circuit using a vapor compression refrigeration cycle and circulates air in the refrigerator to cool an object to be cooled such as food. For example, the refrigerant circuit includes a cooler that cools the air in the refrigerator by using evaporation of the refrigerant. Here, the cooler is a heat exchanger having, for example, a plurality of heat transfer tubes through which the refrigerant passes and a plurality of plate-like fins for expanding the heat transfer area.

Here, when the refrigerator cooler cools the air in the refrigerator, the surface temperature decreases to near -30 ° C. For this reason, the water vapor | steam contained in the air in a refrigerator will become frost on the surface of a cooler (it will form frost). When the frost is formed, the space between the fins of the cooler is narrowed to cause clogging and the like, and the ventilation resistance is increased. For this reason, there existed a problem that the cooling performance of a refrigerator fell and power consumption increased. Therefore, in the refrigerator, in order to remove the frost from the cooler, a defrosting operation (defrosting) is periodically performed. During the defrosting operation, an extra input such as a defrosting heater is required, so that the power consumption increases as the number of times increases.

In order to solve these problems, a refrigerator for reducing the number of defrosting has been proposed. For example, a cooling room is provided on the back of the freezer room and the vegetable room, and the cooler is arranged across the freezer room and the vegetable room, so that the air returning from the freezer room and the air returning from the freezer room flow to the cooler. A refrigerator in which the entrance is divided has been proposed. By dividing the inlet, the cooler is uniformly frosted to prevent clogging of the cooler (see, for example, Patent Document 1).

In addition, a refrigeration and refrigeration cooler for cooling the refrigeration space and the refrigeration space exclusively, and a refrigeration and refrigeration fan for circulating air between each cooling space and each cooler were provided. A refrigerator has been proposed. In this refrigerator, the thickness of the heat insulating layer outside the main body is reduced by arranging the coolers provided on the back of each space so that at least a part thereof overlaps in the front-rear direction (for example, patents) Reference 2).

Japanese Patent No. 4375220 (Fig. 2) Japanese Patent No. 4488966 (Fig. 2)

For example, in the refrigerator described in Patent Document 1 described above, it is possible to make the frost on the cooler uniform. However, a cooler is installed between the freezer compartment and the vegetable compartment, and the freezer return air path is installed in the center of the cooler. For this reason, there has been a problem that the heat transfer area through which the air returning from the freezer compartment to the cooler passes through the cooler is reduced, and is not sufficiently cooled.

For example, in the refrigerator described in Patent Document 2, it is possible to reduce the thickness of the heat insulating layer. However, since the refrigerators for refrigeration and freezing are provided, the volume of the air passage in the refrigerator is increased, and the internal volume is reduced accordingly. In addition, there is a problem that the cost becomes high.

Therefore, an object is to obtain a highly efficient refrigerator by reducing costs and preventing clogging due to frost formation.

The present invention has been made to solve the above-described problem, and in a refrigerator having a refrigerator compartment and a freezer compartment, the refrigerant has a heat transfer tube through which refrigerant passes and a plurality of fins arranged so that air from the refrigerator compartment passes through. The part to be operated is configured so that the fin pitch is wider and / or the number of fins is smaller than the part through which air from the freezer passes, and is located outside the refrigerator, and heat exchange with the refrigerant is performed to store the freezer and the refrigerator. A cooler that cools air from the room, a circulation fan that circulates air between the room and the cooler, and a dedicated fan that sends the air cooled by the cooler to the refrigerator compartment.

According to the present invention, since the fin pitch in the part through which air from the refrigerator compartment passes is wide and / or the number of fins is small, the ventilation resistance due to frost formation on the refrigerator cooler can be reduced, Moreover, since the frequency | count of defrosting can be shortened, defrosting time can be shortened, etc., a highly efficient refrigerator can be obtained. In addition, since the air from the refrigerator compartment has a higher temperature than the air from the refrigerator compartment, the temperature difference from the outside air can be achieved by placing the part through which the air from the refrigerator compartment passes outside. The heat intrusion due to outside air can be reduced. For this reason, it becomes possible to improve cooling performance and to reduce power consumption. And by realizing with one cooler, it is possible to reduce the volume related to the cooler and increase the internal volume.

It is a figure for demonstrating the external appearance and structure of a refrigerator which show Embodiment 1 of this invention. It is a figure which shows the structure of the refrigerant circuit in a refrigerator. It is a figure which shows schematic structure of the evaporator 31 vicinity in the conventional refrigerator. It is a figure which shows the change of the temperature of the freezer compartment return air 37 when passing the evaporator 31. FIG. It is a figure which shows the cooler 15 in Embodiment 1 of this invention. It is a figure which shows arrangement | positioning of the cooler 15 in Embodiment 1 of this invention. It is a figure which shows the cooler 15 in Embodiment 2 of this invention. It is a figure which shows arrangement | positioning etc. of the defrost heater.

Embodiment 1 FIG.
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a view for explaining the appearance and structure of a refrigerator according to Embodiment 1 of the present invention. Fig.1 (a) is an external view seen from the door part 12 side (front side) of the refrigerator, and FIG.1 (b) is sectional drawing for demonstrating the inside of a refrigerator. In the refrigerator, the inside 11 can be sealed with the door 12 and the heat insulating wall 13 to insulate the outside (outside air) from the outside.

Here, the refrigerator compartment 11 has a plurality of rooms. In this embodiment, it is assumed that a refrigerator compartment and a freezer compartment are provided. The refrigerating room is a room for cooling (refrigerating) food or the like (an object to be cooled) with the room air at about 4 ° C., for example. The freezing room is a room for cooling (freezing) foods and the like with room air at about −18 ° C. Here, although the refrigerator having the refrigerator compartment and the freezer compartment is described in FIG. 1, it is possible to achieve the effects described below also for the refrigerator having the vegetable compartment, the ice making compartment, and the like. .

In the refrigerator of the present embodiment, the circulation fan 16 passes the air in the refrigerator 11 (freezer compartment, refrigerator compartment) through the cooler 15 and sends it to the refrigerator 11 again. The dedicated fan 17 is a dedicated fan for the refrigerator compartment for sending the air cooled by the cooler 15 together with the circulation fan 16 to the refrigerator compartment. By having the dedicated fan 17, the air volume in the air circulating between the refrigerators can be adjusted independently. Here, the dedicated fan 17 shown in FIG. 1 is a dedicated fan for cooling the refrigerator compartment. However, for example, when there are other rooms (rooms), not only the refrigerator compartment but also, for example, above the freezer compartment. It can be used as a fan used to cool a room.

The refrigerator of the present embodiment uses a vapor compression refrigeration cycle, for example, performs a cooling operation so as to compensate for heat intrusion from outside air through opening and closing of the door 12 of the refrigerator and the heat insulating wall 13, The inside temperature in the 11 freezer compartments and the refrigerator compartment is maintained.

FIG. 2 is a diagram showing the configuration of the refrigerant circuit in the refrigerator of the present embodiment. In FIG. 2, a compressor circuit, a piping group 21, an expansion means 22 and a cooler 15 are connected to form a refrigerant circuit. Here, for example, isobutane is used as the refrigerant circulating in the refrigerant circuit.

The compressor 14 sucks the refrigerant, compresses it, and discharges it in a high temperature / high pressure state. The piping group 21 is embedded in the heat insulating wall 13. The piping group 21 functions as a condenser, and dissipates heat to the refrigerant so as to be condensed and liquefied. The expansion means 22 expands the refrigerant that passes therethrough by reducing the pressure. For example, a capillary tube (capillary tube) or the like is used.

The cooler 15 evaporates the refrigerant by exchanging heat with the air 23. The cooler 15 of the present embodiment is, for example, a fin tube type that includes a plurality of fins arranged in parallel so that plate-like surfaces are parallel to each other and heat transfer tubes that pass through the fins in the parallel arrangement direction. It is a heat exchanger. The refrigerant circulating in the refrigerant circuit passes through the heat transfer tube. The configuration of the cooler 15 will be further described later.

In the refrigerator according to the present embodiment, the air 23 flowing from the inside 11 (freezer compartment, refrigerated compartment) is cooled by a single cooler 15, and the respective inside temperatures of the freezer compartment and the refrigerator compartment are maintained. The air 23 is air that flows into the cooler 15 from the interior 11 (refrigeration room, freezing room) by driving the circulation fan 16 and the dedicated fan 17. After passing through the cooler 15, it is sent again to the interior 11 (refrigerated room, freezer room). Here, in the refrigerator of the present embodiment, the air that flows from the refrigerator compartment (hereinafter referred to as the refrigerator return air) and the air that flows from the refrigerator compartment (hereinafter referred to as the refrigerator return air) are different from each other in the cooler 15. It is assumed that the air path into which air flows from at least the interior 11 is divided so as to pass through the portion.

Next, the operation of the equipment in the refrigerant circuit during the cooling operation of the refrigerator will be described based on the circulating refrigerant flow. The compressor 14 sucks the refrigerant, compresses it, and discharges it in a high temperature / high pressure state. The compressed refrigerant flows into the pipe group 21 and dissipates heat in the pipe group 21 to become a liquid refrigerant. The liquid refrigerant flows into the expansion means 22 and is decompressed and expanded by the expansion means 22 to become a gas-liquid two-phase refrigerant. In the cooler 15, the gas-liquid two-phase refrigerant exchanges heat with the air 23 that has flowed from the interior 11 by the rotation of the circulation fan 16 and the dedicated fan 17. By the heat exchange in the cooler 15, the gas-liquid two-phase refrigerant absorbs heat from the air 23 and evaporates. The compressor 14 sucks and discharges the refrigerant that has become gas.

On the other hand, the air 23, whose temperature has been reduced due to heat absorbed by the refrigerant, is sent again to the interior 11 by the circulation fan 16 and the dedicated fan 17, and cools the interior 11.

Here, in the refrigerator configured as described above, in the air 23 flowing into the cooler 15, the air inflow state (air temperature and humidity) is greatly different between the refrigerator return air and the freezer return air. This is because the refrigerator compartment has a set temperature of about 4 ° C., whereas the freezer compartment has a temperature of about −18 ° C. In addition, the refrigerator compartment has a larger volume than the freezer compartment, and the surface area increases accordingly, which increases the amount of heat intrusion from the outside air. Further, the refrigerator compartment has a larger number of times of opening and closing the door portion 12, and the amount of outside air intruding into the storage 11 is larger than that of the freezer compartment.

The inventors measured the temperature Tin and humidity φin of the freezer return air and the refrigerator return air, and obtained the following results.
(Refrigerating room return air) Tin = 5 ℃ φin = 80%
(Freezer return air) Tin = -15 ° C φin = 60%

Based on the above results and the air volume of return air from each room, the contribution ratio of the refrigerator return air and the freezer return air in the moisture content of the air 23 flowing into the cooler 15 was calculated. As a result, it was found that the refrigerator return air in the air 23 has a water content of 7 times or more that of the freezer return air. From this, it can be said that the main factor that the cooler 15 forms frost is the return air in the refrigerator compartment.

FIG. 3 is a diagram showing a schematic configuration near the evaporator 31 in a conventional refrigerator. In FIG. 3, the evaporator 31 functions as a cooler. Further, the return air passage 32 becomes a wind passage for the return air 36 in the refrigerator compartment. The defrosting heater 33 serves as a heating means for heating the cooler 15 when the evaporator 31 is defrosted. The dew receiving tray 34 receives, for example, dew dropped from the cooler 15 when defrosting is performed. The guide plate 35 guides the refrigerating room return air 36 and sends it out to the cooler 15 through the opening 35a. The refrigerating room return air 36 is air flowing from the refrigerating room as described above. The freezer return air 37 is air flowing from the freezer compartment.

FIG. 4 is a diagram showing a change in the temperature of the freezer return air 37 when passing through the cooler 15. As shown in FIG. 4B, the temperature of the freezer return air 37 approaches the temperature of the evaporator 31 as it proceeds in the X direction shown in FIG. 4A (the direction toward the outlet from the cooler 15). To go. The freezer return air 37 has a temperature substantially equal to that of the evaporator 31 in the vicinity of the outlet from the evaporator 31.

From this, if the air volume of the freezer return air 37 and the temperature of the evaporator 31 are constant, the evaporator 31 outlet of the freezer return air 37 depends on the size of the evaporator 31 (distance passing through the evaporator 31). The temperature at is determined. If the sizes of the evaporators 31 are the same, when the freezer return air 37 is introduced from the middle of the cooler 15, the passage distance is reduced, so that the freezer return air 37 also has an outlet of the cooler 31. The temperature does not fall down and there is a possibility of insufficient cooling capacity.

FIG. 5 is a diagram showing the cooler 15 according to the first embodiment of the present invention. Fig.5 (a) shows the perspective view of the cooler 15 in this Embodiment 1. FIG. FIG. 5B shows a top view of the cooler 15, and FIG. 5C shows a front view of the cooler 15 as viewed from the inside. For example, as shown in FIG. 5 (b), the cooler 15 of the present embodiment has a structure in which the fin pitch on the back side (outside of the box) viewed from the inside of the box is widened and a region in which the number of fins is reduced is provided. To do. Then, through this region, the return air having a high water content passes through to reduce clogging due to frost. Here, in FIG. 5, both the fin pitch and the number of fins are changed, but it is possible to reduce clogging with only one of them (widening the fin pitch or reducing the number of fins). It is. Further, although not particularly limited, the ratio in the air path (volume) between the part with the wide fin pitch and the part with the fin pitch not widened is, for example, 1: 2 (the flow rate due to the return air in the refrigerator compartment is reduced). ).

Here, in the refrigerator of the present embodiment, as described above, the freezer return air and the refrigerating room return air pass through the cooler 15 so that the temperature related to the freezer return air can be lowered as much as possible. The same distance. This prevents a shortage of cooling capacity of the freezer return air. Further, as described above, the path (wind passage) through which the return air to the refrigerator compartment passes in the cooler 15 is formed in a region close to the outside of the warehouse, which is the back side when the refrigerator is viewed from the inside of the cabinet (front side). Like to do. The reason is to reduce the amount of heat penetration from the outside air. For example, as shown in FIG. 1, the cooler 15 and the outside air are insulated from each other through a heat insulation wall 13. Generally, urethane foam and vacuum heat insulating material are used for the heat insulating wall 13. And the amount Q of heat penetration from the outside air can be expressed as the following equation (1). Here, A is an area, K is a heat transmission rate determined by the structure of the heat insulating wall 13, and ΔT represents a temperature difference between the cooler 15 and the outside air.
Q = A · K · ΔT (1)

From equation (1), it is desirable to reduce the temperature difference ΔT in order to reduce the amount of heat intruding into the interior 11 by the outside air. If the outside air is constant, the heat intrusion increases as the temperature of the cooler 15 increases. The amount can be reduced. As described above, in the refrigerated room return air and the freezer room return air, the freezer room return air is about 20 ° C. lower, and when the freezer room return air passes outside the warehouse, the temperature difference ΔT with the outside air becomes large. Therefore, in the present embodiment, in the cooler 15, the return air in the refrigerator compartment passes through the outside of the refrigerator. For example, when the outside air is set to 30 ° C., the amount of heat penetration can be reduced by 45% by allowing the return air from the refrigerator compartment to pass through the outside of the cooler 15. When it is not necessary to circulate air between the refrigerator compartment, for example, the freezer return air can be introduced into the region of the cooler 15 having a wide fin pitch so that the return air can flow into the refrigerator 15. A damper may be provided on the side so that switching can be performed.

FIG. 6 is a diagram showing the arrangement of the cooler 15 in the first embodiment of the present invention. Fig.6 (a) is a figure which shows arrangement | positioning when it sees from the front side of a refrigerator. FIG.6 (b) is a figure which shows arrangement | positioning when it sees from the upper surface side of a refrigerator. As shown in FIG. 6, the refrigerating room return port 18 is provided on the front surface of the cooler 15 perpendicular to the cooler 15, and flows into the back surface of the cooler 15 from the lower portion of the cooler 15. On the other hand, the freezer return port (not shown) is provided upward from the lower portion of the cooler 15 and flows into the front surface of the cooler 15.

From the above, according to the refrigerator of the first embodiment, in the cooler 15, the fin pitch in the portion through which the return air for the refrigerator compartment passes is widened or the number of fins is reduced. Clogging due to frost can be reduced, and increase in ventilation resistance due to frost can be suppressed. Moreover, the temperature difference with external air can be made small and the amount of heat | fever penetration | invasion from external air can be decreased by making the path | route into which the refrigerator compartment return air flows becomes the warehouse outside of the cooler 15. From the above, a highly efficient refrigerator can be obtained.

Embodiment 2. FIG.
FIG. 7 is a diagram showing a cooler 15 according to Embodiment 2 of the present invention. The arrangement of the cooler 15 in the refrigerator is the same as that of the refrigerator of the first embodiment. The cooler 15 in FIG. 7 has a defrost heater 61 that directly heats in contact with the cooler body. Further, a large number of defrosting heaters 61 are arranged in the cooler 15 in a portion close to the position where the refrigerating room return air, which is the main cause of frost formation, passes. 7A is a perspective view of the cooler 15 according to the second embodiment, FIG. 7B is a top view of the cooler 15 according to the second embodiment, and FIG. 7C is a cooler 15 according to the second embodiment. It is the figure seen from the surface side through which freezer compartment return air flows.

In this cooler 15, as shown in FIG. 7B, a structure is provided in which a fin pitch is widened on the surface opposite to the surface on which the freezer return air flows, and a region in which the number of fins is reduced is provided. To do. Even in the cooler 15 of the present embodiment, it is possible to achieve the effect of reducing clogging due to frost only by increasing the fin pitch or reducing the number of fins. Here, since the structure of the refrigerator having the cooler 15, the refrigerant circuit, and the like in the second embodiment are the same as those in the first embodiment, only the differences from the first embodiment will be described in the present embodiment.

FIG. 8 is a diagram showing the arrangement and the like of the defrost heater 61. As shown in FIG. 8, in this Embodiment, the defrost heater 61 which supplies heat to the cooler 15 from the outside is provided for a defrost. And it arrange | positions so that the number of the defrost heaters 61 may increase in the area | region where the fin pitch of the cooler 15 is wide, the number of fins is small, and the refrigerator compartment return air passes.

As described in the first embodiment, the amount of water contained in the return air from the refrigerator compartment is larger than the amount of water contained in the return air from the freezer compartment, so that the amount of frost on the fin is the portion through which the return air from the refrigerator compartment passes. Will increase. Therefore, a defrost heater 61 is provided so that the region through which the return air for the refrigerator compartment passes can be preferentially heated. For this reason, defrosting time can be shortened compared with the case where it arranges equally. Moreover, the rise in the internal temperature during defrosting can be suppressed by reducing the defrosting time. Therefore, a highly efficient refrigerator can be obtained.

By using the present invention, the cooling performance of the refrigerator can be improved, and a highly efficient refrigerator can be obtained. Moreover, power consumption can be reduced by shortening the defrosting time.

11 interior, 12 door part, 13 heat insulation wall, 14 compressor, 15 cooler, 16 circulation fan, 17 dedicated fan, 18 refrigerator compartment return, 21 piping group, 22 expansion means, 23 air, 31 evaporator, 32 Return air passage, 33 heater for defrost, 34 dew tray, 35 guide plate, 35a opening, 36 return air for refrigerator compartment, 37 return air for freezer compartment, 61 defrost heater.

Claims

In a refrigerator having a refrigerator compartment and a freezer compartment,
It has a heat transfer tube through which the refrigerant passes and a plurality of fins arranged, and the part through which the air from the refrigerator compartment passes is wider than the part through which the air from the freezer compartment passes and / or the number of fins And a cooler that cools the air from the freezer compartment and the refrigerator compartment by exchanging heat with the refrigerant,
A circulation fan for circulating air between the refrigerator and the cooler;
A refrigerator comprising a dedicated fan for sending air cooled by the cooler to the refrigerator compartment.
Further comprising heating means for defrosting the cooler;
The said heating means is comprised so that it may supply more heat to the part through which the air from the said refrigerator compartment passes in the said cooler rather than the part through which the air from the said freezer compartment passes. refrigerator.
The refrigerator according to claim 2, wherein the heating means is disposed in contact with the cooler.
The refrigerator compartment is located above the freezer compartment,
The refrigerator according to any one of claims 1 to 3, wherein the dedicated fan is disposed so as to be positioned above a position where the freezer compartment is located.
The refrigerator according to any one of claims 2 to 4, wherein the heating means supplies heat from outside the cooler.
The refrigerator according to any one of claims 1 to 5, wherein the cooler is configured such that a portion through which air from the refrigerator compartment passes is narrower than a portion through which air from the freezer compartment passes.