JP7036698B2 - Freezer refrigerator - Google Patents

Description

The present invention relates to a freezer / refrigerator. In particular, it relates to a freezer / refrigerator having a defrosting function.

As defrosting of the conventional refrigerator / freezer, while the compressor is operating, the inflow prevention valve for preventing the refrigerant from flowing into the evaporator is closed, and the refrigerant in the evaporator is forcibly reduced. There is a method of defrosting by generating heat from a defrosting heater (see, for example, Patent Document 1).

FIG. 7 is a freezing cycle piping diagram showing a method of defrosting a conventional refrigerator / freezer described in Patent Document 1.

The freezer / refrigerator of FIG. 7 has a compressor 101, a condenser 102, a dryer 103, a decompressor 104 (capillary tube), an evaporator 105, and a heater 106 for defrosting. An inflow prevention valve 107 is installed between the condenser 102 and the dryer 103. While the compressor 101 is in operation, the inflow prevention valve 107 is closed to forcibly reduce the amount of refrigerant in the evaporator 105. In that state, defrosting is performed by the heat generated by the defrosting heater 106. This makes it possible to prevent the heat of the defrosting heater 106 from being used for the heat of vaporization of the refrigerant in the evaporator 105.

Japanese Unexamined Patent Publication No. 10-38453

However, in the conventional configuration, since the refrigerant is reduced from the inside of the evaporator 105 at the time of defrosting, it is difficult to obtain the effect of equalizing the heat above and below the evaporator 105 by the refrigerant. When it becomes difficult to obtain such an effect, temperature variation occurs, such as a delay in raising the temperature of the upper part of the evaporator 105 and insufficient temperature rise at the inlet of the evaporator 105 to which a large amount of frost is attached. As a result, it takes a long time to complete the defrosting of the entire evaporator 105, the inside of the refrigerator / freezer becomes warm, and electric power is required to cool it again.

In addition, since the defrosting time is long, the energizing time of the defrosting heater 106 is also long, and the power consumption of the heater is also increased. In addition, due to temperature variation, defrosting was completed with partial frost remaining, and there was a risk that the cooling load after the completion of defrosting would increase.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a freezer / refrigerator for efficiently using the heat of a defrosting heater without waste.

In order to achieve the above object, the freezer and refrigerator of the present invention
Compressors, condensers, dryers, decompressors and evaporators that make up the refrigerant cycle,
The first pipe including the inlet pipe of the evaporator and
The second pipe including the outlet pipe of the evaporator and
A first heat coupling portion that thermally couples the decompressor and the second pipe,
A second heat coupling portion that thermally couples the first pipe and the second pipe,
To prepare for.

With this configuration, the finless part on the inlet side of the evaporator where it is difficult to raise the temperature of the upper part of the evaporator due to the outlet side piping warmed by the latent heat of condensation of the refrigerant vaporized by the heat of the heater for defrosting at the lower part of the evaporator. The temperature of the inlet pipe can also be raised.

As described above, according to the configuration of the evaporator of the freezer / refrigerator of the present invention, the heat of the defrosting heater at the time of defrosting can be efficiently used without waste.

Piping diagram of the refrigeration cycle according to the first embodiment of the present invention Front view of the evaporator according to the first embodiment of the present invention. Side view of the evaporator according to the first embodiment of the present invention. The figure which shows an example of the 2nd thermal coupling part in Embodiment 1 of this invention. The figure which shows an example of the 2nd thermal coupling part in Embodiment 1 of this invention. The figure which shows an example of the 2nd thermal coupling part in Embodiment 1 of this invention. The figure which shows an example of the 2nd thermal coupling part in Embodiment 1 of this invention. The figure which shows an example of the 2nd thermal coupling part in Embodiment 1 of this invention. The figure which shows an example of the 2nd thermal coupling part in Embodiment 1 of this invention. The figure which shows an example of the 2nd thermal coupling part in Embodiment 1 of this invention. The figure which shows an example of the 2nd thermal coupling part in Embodiment 1 of this invention. Front view showing the thermal coupling between the inlet pipe of the evaporator and the accumulator in the second embodiment of the present invention. Front view showing the configuration in which the inlet pipe of the evaporator in the third embodiment of the present invention passes through the accumulator. A freezing cycle piping diagram showing a method of defrosting a conventional refrigerator / freezer described in Patent Document 1.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a diagram showing a piping of a refrigeration cycle and its components according to the first embodiment of the present invention. FIG. 2A is a front view of the evaporator 5. FIG. 2B is a side view of the evaporator 5.

In FIG. 1, the refrigerator / freezer has a compressor 1, a condenser 2, a dryer 3, a decompressor 4 (for example, a capillary tube), an evaporator 5, a heater for defrosting 6, a first thermal coupling portion 9, and a second thermal coupling. It has a portion 8 and a pipe 16. The compressor 1, the condenser 2, the dryer 3, the decompressor 4, and the evaporator 5 are connected by a pipe 16. The refrigerant passes through the pipe 16. The pipe 16 has a first pipe 16a and a second pipe 16b. The first pipe 16a connects the outlet of the refrigerant of the decompressor 4 and the inlet of the refrigerant of the evaporator 5. The second pipe 16b connects the outlet of the refrigerant of the evaporator 5 and the inlet of the compressor 1. Here, the first pipe 16a includes the inlet pipe 12a of the evaporator 5. Further, the second pipe 16b includes an outlet pipe 12b of the evaporator 5.

The compressor 1 has a role of compressing the refrigerant in the gas phase in the refrigeration cycle and circulating the refrigerant in the refrigeration cycle.

The condenser 2 condenses and liquefies the compressed gas phase refrigerant, and releases the latent heat of condensation of the refrigerant.

The dryer 3 adsorbs the moisture in the refrigeration cycle.

The decompressor (eg, capillary tube) 4 reduces the pressure of the liquid phase refrigerant.

The evaporator 5 vaporizes the decompressed liquid phase refrigerant, and cools the inside of the refrigerator by using the latent heat of vaporization of the refrigerant.

The defrosting heater 6 is for melting the frost attached to the evaporator 5, and is arranged in the lower part of the evaporator 5 in the present embodiment.

The first heat coupling portion 9 thermally couples the decompressor 4 and the second pipe 16b. During the cooling operation in which the compressor 1 is operating, heat exchange is performed between the high-temperature refrigerant passing through the decompressor 4 and the low-temperature refrigerant discharged from the outlet of the evaporator 5 to improve the cooling performance. .. The first heat coupling portion 9 is a member that connects pipes to each other and transfers heat. The material of the first heat coupling portion 9 is a metal, a carbon material, or the like.

As shown in FIG. 2A, the pipe expansion point 13 is provided in the pipe upstream of the inlet pipe 12a. The diameter of the pipe is increased at the expansion point 13, and the diameter is the same as that of the pipe 12, which is connected to the pipe 12 of the evaporator 5. The pipe expansion portion 13 is a portion of the first pipe 16a where the pipe diameter is large. The pipe diameter on the downstream side of the pipe expansion point 13 is larger than the pipe diameter on the upstream side of the pipe expansion point 13 (for example, the cross-sectional area is about 2 to 5 times larger). The expansion tube portion 13 is for expanding the refrigerant flowing in the decompressor 4.

As shown in FIG. 2A, the second heat coupling portion 8 thermally couples the pipe on the downstream side of the pipe expansion portion 13 and the outlet pipe 12b. During the defrosting operation in which the compressor 1 is stopped and the defrosting heater 6 is energized, the heat of the defrosting heater 6 is transferred from the outlet pipe 12b to the pipe (provided in the inlet pipe 12a) on the downstream side of the pipe expansion point 13. Since it is transmitted, there is no delay in raising the temperature of the upper part of the evaporator 5 far from the heater 6, and there is no insufficient temperature rise at the inlet of the evaporator 5 to which a large amount of frost is attached, so that the occurrence of temperature variation can be suppressed. can. This has the effect of efficiently using the heat of the defrosting heater 6. The second heat coupling portion 8 is a member that connects pipes to each other and transfers heat, similarly to the first heat coupling portion 9. The material of the second heat coupling portion 8 is a metal, a carbon material, or the like.

The refrigerating cycle configured as described above is cooled and operated, and the cold air produced by the evaporator 5 is exchanged for heat using a fan and circulated in the freezer / refrigerator to freeze / cool and store the food.

At that time, the water deprived from the food adheres to the evaporator 5 as frost, and the heat exchange performance of the evaporator 5 deteriorates as the frost grows. In order to reset this deterioration in heat exchange performance, the cooling operation is temporarily stopped (that is, the compressor 1 is stopped), the defrosting heater 6 is energized, and the evaporator 5 is heated to perform defrosting. This series of operations is called defrosting operation. During this defrosting operation, the liquid refrigerant in the evaporator 5 is also vaporized.

<Structure of evaporator 5>
FIG. 2A is a front view of the evaporator 5 according to the first embodiment. In the evaporator 5, one horizontal pipe 12 is arranged in a row in the front-rear direction with 10 steps in the vertical direction and meandering in the horizontal direction. A heat exchange promoting fin is attached to the pipe 12. The evaporator 5 is a fin-and-tube heat exchanger, and in FIG. 2A, the front pipe 12 is shown. At the inlet from the decompressor 4, there is an inlet pipe 12a. The inlet pipe 12a is connected to the pipe 12, and the pipe 12 meanders downward as described above. The pipe 19 at the end of the final end of the pipe 12 is located below. The pipe 19 at the end is connected to the return vertical pipe 11 extending in the vertical direction (from bottom to top) without meandering. The return vertical pipe 11 is connected to the outlet pipe 12b.

FIG. 2B is a side view of another example evaporator 5. In FIG. 2A, the pipe row 18 which is a mass of the pipes 12 is one row, but in FIG. 2B, the pipe rows 18 are three rows in the front-rear direction. The pipe 12 is connected by the lower part of the pipe row 18 in the first row and the lower part of the pipe row 18 in the second row. The pipe 12 is connected by the upper part of the pipe row 18 in the second row and the upper part of the pipe row 18 in the third row.

When the pipe row 18 is an odd number of rows, the outlet pipe 12b of the evaporator 5 located at the lower part and the inlet pipe 12a arranged at the upper part of the evaporator 5 are largely separated in the vertical direction. In the present embodiment, the pipe 19 at the outlet side end of the evaporator 5 located at the lower part is connected to the return vertical pipe 11 extending in the vertical direction (from bottom to top). The return vertical pipe 11 is connected to the outlet pipe 12b. As a result, both the inlet pipe 12a (the pipe on the downstream side of the pipe expansion portion 13) and the outlet pipe 12b are located close to each other, and a second heat coupling portion 8 in which both are thermally coupled to each other is provided.

A part of the return vertical pipe 11 and a part of the inlet pipe 12a are welded to each other at the second heat coupling portion 8 (corresponding to the “bonding portion” of the present invention) to be thermally coupled.

3A to 3C are views showing an example of the second heat coupling portion 8. A cross-sectional view of the second heat coupling portion 8 cut along a plane orthogonal to the flow direction of the refrigerant is shown on the upper side of FIG. 3A, and a perspective view of the second heat coupling portion 8 is shown on the lower side of FIG. 3A.

The second heat coupling portion 8 has a welded portion 15. As shown in FIG. 3A, the welded portion 15 joins the outlet pipe 12b and the inlet pipe 12a. The welded portion 15 is provided in a rod shape along the tangent line between the outlet pipe 12b and the inlet pipe 12a.

Further, the second heat coupling portion 8 may have a welded portion 15. As shown in FIG. 3B, the welded portion 15 has a portion provided in a rod shape along the tangent line between the outlet pipe 12b and the inlet pipe 12a, and a triangular columnar portion provided on both sides thereof. The welded portion 15 is provided by overlaying. Since the area of contact between the outlet pipe 12b and the inlet pipe 12a via the welded portion 15 increases, the effect of heat exchange can be improved.

Further, the second heat coupling portion 8 may have a welded portion 15. The welded portion 15 joins a flat surface made by crushing the outlet pipe 12b in the radial direction and a flat surface made by crushing the inlet pipe 12a in the radial direction. Since the area in which the outlet pipe 12b and the inlet pipe 12a come into contact with each other via the welded portion 15 increases, the effect of heat exchange can be improved.

4A to 4B are views showing another example of the second heat coupling portion 8.
The second heat coupling portion 8 shown in FIG. 4A or FIG. 4B mechanically heat-bonds the outlet pipe 12b and the inlet pipe 12a by a member having good heat conduction (copper or the like).

The second heat coupling portion 8 shown in FIG. 4A thermally couples the outlet pipe 12b and the inlet pipe 12a by bundling the outlet pipe 12b and the inlet pipe 12a with the heat conductive member 14.

The second heat coupling portion 8 shown in FIG. 4B heat-bonds the outlet pipe 12b and the inlet pipe 12a by filling the region including the gap between the outlet pipe 12b and the inlet pipe 12a with the heat conductive member 14. Is.

4C to 4E are views showing another example of the second heat coupling portion 8.
FIG. 4C is a side view of the second heat coupling portion 8. The second heat coupling portion 8 shown in FIG. 4C thermally couples the outlet pipe 12b and the inlet pipe 12a by winding the outlet pipe 12b around the outer periphery of the inlet pipe 12a extending linearly.

FIG. 4D is a plan view of the second heat coupling portion 8. FIG. 4E is a cross-sectional view of the second heat coupling portion 8. The second heat coupling portion 8 shown in FIGS. 4D and 4E heat-bonds the outlet pipe 12b and the inlet pipe 12a by covering the linearly extending inlet pipe 12a with the outlet pipe 12b. In other words, the inlet pipe 12a extending linearly is arranged in the outlet pipe 12b. The thermal coupling portions 8 shown in FIGS. 3A to 4E may be combined.

<Effect>
According to this configuration, during the defrosting operation, the refrigerant collects in a liquid state in the lower part of the evaporator 5 and is vaporized by the heat of the defrosting heater 6. Since the vaporized refrigerant passes through the return vertical pipe 11 and exits, the temperature of the pipe on the outlet side is relatively equal to the saturation temperature of the refrigerant. Compared to the outlet side, the finless portion of the inlet pipe 12a above the evaporator 5 is less likely to receive the heat of the defrosting heater 6, and because it is the coldest portion, the amount of frost formation is large and the temperature rise is slow. The temperature rise can be promoted by thermally coupling the portion of the inlet pipe 12a with the outlet pipe 12b heated by the vaporized refrigerant at the second heat coupling portion 8. This makes it possible to suppress the overall temperature variation of the evaporator 5. By doing so, the heat of the heater 6 for defrosting is not wasted, and the inlet pipe 12a of the evaporator 5, which has been difficult to heat in the past, can be heated by the latent heat of condensation of the refrigerant. ..

In the present embodiment, the inlet pipe 12a is arranged at the upper part and the outlet pipe 12b is arranged at the lower part to configure the piping path of the evaporator 5, but the effect can be obtained even in the reverse configuration.

(Embodiment 2)
FIG. 5 is a piping diagram of the evaporator 5 of the second embodiment of the present invention as viewed from the front. In FIG. 5, the same reference numerals are used for the same components as those in FIGS. 1 and 2, and the description thereof will be omitted. The portion not described is the same as that of the first embodiment.

The evaporator 5 is a fin-and-tube type heat exchanger with 10 stages in the vertical direction and 1 row in the front-rear direction, and the fins 10 are shown in a simplified form in this figure. During the cooling operation, the liquid refrigerant accumulates in the lower part of the return vertical pipe 11 due to gravity. An accumulator 7 is arranged in order to prevent the liquid refrigerant from returning to the compressor 1 and causing compression of the liquid. The outer frame of the accumulator 7 and a part of the inlet pipe 12a are thermally coupled by the second heat coupling portion 8.

The second heat coupling portion 8 may be one in which the outer frame of the accumulator 7 and the inlet pipe 12a are welded, or one in which the inlet pipe 12a is wound around the outer frame of the accumulator 7, or a combination thereof. It may be an accumulator.

<Effect>
According to this configuration, during the defrosting operation, the refrigerant that collects in a liquid state in the lower part of the evaporator 5 and is vaporized by the heat of the defrosting heater 6 passes through the return vertical pipe 11 and is condensed by the accumulator 7. Therefore, the temperature rise of the piping on the outlet side and the accumulator 7 is relatively equal to the saturation temperature of the refrigerant. Compared to the outlet side, the part of the upper part of the evaporator 5 where the inlet side piping does not have fins is harder for the heat of the heater to reach, and since it is the lowest temperature part, the amount of frost formation is large and the temperature rise is slow. By heating this portion with the vaporized refrigerant and thermally coupling it with the accumulator 7 having a heat capacity larger than that of the piping portion to promote the temperature rise, it is possible to suppress the temperature variation of the entire evaporator 5.

By doing so, the heat of the defrosting heater 6 used for vaporizing the refrigerant is not wasted, and the inlet portion of the evaporator 5 which has been difficult to heat in the past is heated by the latent heat of condensation of the refrigerant. be able to.

(Embodiment 3)
FIG. 6 is a piping diagram of the evaporator 5 of the third embodiment of the present invention as viewed from the front. In FIG. 6, the same reference numerals are used for the same components as those in FIGS. 1 and 2 and 3, and the description thereof will be omitted. The parts not described are the same as those of the first and second embodiments.

The evaporator 5 is a fin-and-tube type heat exchanger with 10 stages in the vertical direction and 1 row in the front-rear direction, and the fins 10 are shown in a simplified form in this figure. An accumulator 7 for preventing the liquid refrigerant from returning to the compressor 1 is arranged in the return vertical pipe 11. A part of the inlet pipe 12a passes through the inside of the accumulator 7.

<Effect>
According to this configuration, the refrigerant that has accumulated in the lower part of the evaporator 5 in a liquid state during the defrosting operation and is vaporized by the heat of the defrosting heater 6 passes through the return vertical pipe 11 and is condensed by the accumulator 7. Therefore, the temperature rise of the piping on the outlet side and the accumulator 7 is relatively equal to the saturation temperature of the refrigerant. Compared to the outlet side, the part of the upper part of the evaporator 5 where the inlet side piping does not have fins is harder for the heat of the heater to reach, and since it is the lowest temperature part, the amount of frost formation is large and the temperature rise is slow. This part is warmed by the vaporized refrigerant and passes through the accumulator 7 which has a larger heat capacity than the piping part to suppress frost formation during the cooling operation and promote the temperature rise during the defrosting operation to evaporate during defrosting. It is possible to suppress the temperature variation of the entire vessel. By doing so, the heat of the defrosting heater 6 used for vaporizing the refrigerant is not wasted, and the inlet portion of the evaporator 5 which has been difficult to heat in the past is heated by the latent heat of condensation of the refrigerant. be able to.

In each of the above embodiments, in a heat exchanger in which a predetermined number of horizontal pipes in the vertical direction are arranged in a predetermined number of rows in the front-rear direction, a coupling portion in which the inlet pipe 12a and the outlet pipe 12b are thermally coupled is shown. The invention is not limited to this, and for example, in a heat exchanger in which horizontal pipes having a predetermined number of rows in the front-rear direction are arranged in a predetermined number of stages in the vertical direction, a joint portion in which an inlet pipe 12a and an outlet pipe 12b are thermally coupled may be used.

The refrigerator-freezer of the present application is widely used not only as a household refrigerator-freezer, but also as a commercial-use refrigerator-freezer. Furthermore, it is also used as a freezer / refrigerator for mobile objects such as automobiles and ships.

1 Compressor 2 Condenser 3 Dryer 4 Decompressor (capillary tube)
5 Evaporator 6 Heater for defrosting 7 Accumulator 8 Second heat coupling part 9 First heat coupling part 10 Fin 11 Return vertical piping 12 Piping 12a Inlet piping 12b Outlet piping 13 Expansion point 14 Heat conduction member 15 Welding part 16 Piping 16a No. 1 Piping 16b Second piping 18 Piping row 19 Piping at the end 101 Compressor 102 Condensator 103 Dryer 104 Decompressor (capillary tube)
105 Evaporator 106 Defrosting heater 107 Inflow prevention valve

Claims (5)

Compressors, condensers, dryers, decompressors and evaporators that make up the refrigerant cycle,
The first pipe including the inlet pipe of the evaporator and
The second pipe including the outlet pipe of the evaporator and
A first heat coupling portion that thermally couples the decompressor and the second pipe,
A second heat coupling portion that thermally couples the first pipe and the second pipe,
Equipped with
The entire second thermal coupling portion is arranged on the upper part of the entire evaporator.
The pipe of the evaporator is provided with a return vertical pipe connected to the outlet pipe as well as from the bottom to the top, which is connected to the pipe at the end located on the most outlet side of the evaporator.
The pipes of the evaporator are odd rows of three or more rows of pipes in which one pipe is meandered in the horizontal direction by a predetermined number of steps in the vertical direction, in the vertical direction and in the front-rear direction orthogonal to the horizontal direction. Arranged, heat exchange promoting fins are attached to the pipe,
The inlet pipe is provided in the most inlet side of the pipe row located on one side of the plurality of pipe rows in the front-rear direction, and the outlet pipe is located on the other side of the plurality of pipe rows in the front-rear direction. It is installed in the piping row on the farthest outlet side.
The inlet pipe and the outlet pipe are located close to each other by inclining in the front-rear direction toward the central pipe row side in the pipe row in the odd-numbered row.
A freezer / refrigerator provided with a heater for heating the evaporator along the horizontal direction directly below the central piping row . The refrigerator / freezer according to claim 1, wherein the first pipe has a pipe expansion point, and the pipe diameter on the downstream side of the pipe expansion point is larger than the pipe diameter on the upstream side of the pipe expansion point. The freezer / refrigerator according to claim 2, wherein the second heat coupling portion is located on the evaporator side after the tube expansion portion. The freezer / refrigerator according to any one of claims 1 to 3, wherein the second heat coupling portion thermally couples the accumulator provided in the outlet pipe of the evaporator and the inlet pipe of the evaporator. The second thermal coupling portion is any one of claims 1 to 3 composed of an accumulator provided in the outlet pipe of the evaporator and an inlet pipe of the evaporator passing through the inside of the accumulator. Refrigerator as described in the section.

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