JP5709618B2 - Heat exchanger, refrigeration cycle apparatus, refrigerator, and air conditioner - Google Patents

Description

  The present invention relates to a heat exchanger, a refrigeration cycle apparatus including the heat exchanger, a refrigerator, and an air conditioner.

  A heat exchanger constituting a refrigeration cycle apparatus used in a conventional refrigerator, air conditioner or the like is known as a fin tube type heat exchanger. The heat exchanger includes plate-like fins arranged at regular intervals and through which gas (air) flows, and a plurality of circular heat transfer tubes inserted perpendicular to the plate-like fins and through which refrigerant flows. It is comprised by. Factors that affect the heat transfer performance of the finned tube heat exchanger include the refrigerant side heat transfer coefficient between the refrigerant and the heat transfer tube, the contact heat transfer coefficient between the heat transfer tube and the fin, and the air and fin The air side heat transfer coefficient between is known. In order to improve the refrigerant side heat transfer coefficient between the refrigerant and the heat transfer tube, the in-pipe performance is promoted by the expansion of the area of the heat transfer tube and the grooved inner surface of the heat transfer tube that provides the effect of stirring the refrigerant. Moreover, as a method of promoting the air side heat transfer coefficient between the air and the fin, a slit group formed by cutting and raising a plate-like fin between adjacent heat transfer tubes was provided. This slit group is provided so that the side end portion of the slit faces the wind direction, and heat transfer is promoted by thinning the velocity boundary layer and the temperature boundary layer of the air flow at the side end portion. The crack heat exchange capacity is said to increase. The contact heat transfer coefficient between the heat transfer tube and the fin is affected by the contact state between the heat transfer tube and the fin.

A refrigeration cycle apparatus (refrigeration cycle circuit) is formed by sequentially connecting a compressor, a condenser, an expansion valve, and an evaporator with piping. In order to improve the performance of such a refrigeration cycle, the following studies have been made in the prior art.
For example, when a heat transfer tube of an outdoor heat exchanger has a double structure consisting of an inner tube and an outer tube, when defrosting the outdoor heat exchanger during heating operation, the low-temperature liquid refrigerant from the expansion valve is By flowing a part of the high-temperature gas refrigerant discharged from the compressor to the outer pipe through the bypass pipe, the heat of the gas refrigerant is effectively transferred to the fins of the outdoor heat exchanger, and the defrosting time is reduced. It has been proposed that it can be shortened (see, for example, Patent Document 1).
In addition, when the refrigerant condensed in the condenser is further cooled to a temperature equal to or lower than the saturation temperature and sent to the evaporator by the expansion device, the refrigerant dryness at the inlet of the evaporator is reduced and the refrigeration capacity can be increased. Providing a heat exchanger separately is proposed (for example, refer patent document 2).

JP-A-8-261585 (FIG. 1) JP 2009-236396 A (FIG. 1)

However, the above-described prior art has the following problems.
In the technique described in Patent Document 1, all the heat transfer tubes in the entire region of the outdoor heat exchanger have a double structure including an inner tube and an outer tube. And at the time of heating operation before defrosting, the low-temperature liquid refrigerant which came out of the expansion valve is simultaneously flowing into the inner pipe and the outer pipe. For this reason, the refrigerant in the inner pipe has a problem that heat transfer performance (heat exchange capacity) is low because heat exchange is performed between the fins via the refrigerant between the outer pipe and the inner pipe. there were. Moreover, there existed a problem that refrigeration cycle performance fell by applying such a heat exchanger to a refrigeration cycle apparatus.

  Moreover, in the heat exchanger of patent document 2, since the air heat exchanger and the internal heat exchanger were provided separately, there existed a problem that the volume of an outdoor unit was taken significantly and manufacturing cost also rose.

The present invention has been made to solve the above-described problems, and provides a heat exchanger capable of improving heat transfer performance, a refrigeration cycle apparatus including the heat exchanger, a refrigerator, and an air conditioner. is there.
Moreover, the refrigerating-cycle apparatus, refrigerator, and air conditioner which can improve refrigerating-cycle capability are obtained.

A heat exchanger according to the present invention includes a plurality of plate-like fins arranged side by side at a predetermined interval, and a plurality of heat transfer tubes inserted in a direction orthogonal to the plate-like fins, and at least of the plurality of heat transfer tubes. A part has an external heat transfer tube and an internal heat transfer tube, and a heat exchanger that exchanges heat between a heat medium that flows between the external heat transfer tube and the internal heat transfer tube and a heat medium that flows through the internal heat transfer tube A plurality of protrusions extending in the length direction on the inner surface of the external heat transfer tube, and partitioning the flow path between the external heat transfer tube and the internal heat transfer tube on the outer surface of the internal heat transfer tube A plurality of partitions are formed extending in the length direction, and formed on the outer surface of the internal heat transfer tube and an angle formed by a direction in which the protrusions formed on the inner surface of the external heat transfer tube extend and a straight line parallel to the tube axis direction. The direction in which the partition extends and a straight line parallel to the tube axis direction form Is different from the degree, the number of the formed on the inner surface of the outer heat transfer pipe protrusions, the rather multi than the number of the partition formed on the outer surface of the inner heat transfer tube, wherein the projection extends which is formed on the inner surface of the outer heat transfer tube The angle formed by the direction and the straight line parallel to the tube axis direction is larger than the angle formed by the direction in which the partition formed on the outer surface of the internal heat transfer tube extends and the straight line parallel to the tube axis direction .

  The present invention provides an angle formed between a direction in which the protrusion formed on the inner surface of the external heat transfer tube extends and a straight line parallel to the tube axis direction, and a direction in which the protrusion formed on the outer surface of the internal heat transfer tube extends in parallel with the tube axis direction. Since the angle formed by the straight line is different, the heat transfer performance of the heat exchanger can be improved.

It is a front view which shows the outline | summary of the heat exchanger which concerns on Embodiment 1. FIG. It is a side view which shows the outline | summary of the heat exchanger which concerns on Embodiment 1. FIG. 2 is a perspective view showing a configuration of a double pipe according to Embodiment 1. FIG. 2 is a perspective view showing an outline of an internal heat transfer tube according to Embodiment 1. FIG. It is a figure which shows typically the angle which concerns on Embodiment 1, and the protrusion. It is a figure which shows arrangement | positioning in the outdoor unit of the heat exchanger which concerns on Embodiment 1. FIG. It is a front view which shows the outline | summary of the heat exchanger which concerns on Embodiment 1. FIG. It is a side view which shows the outline | summary of the heat exchanger which concerns on Embodiment 1. FIG. FIG. 3 is an explanatory diagram of a tube expansion means for a heat transfer tube according to Embodiment 1. It is a figure which shows the outline | summary of the air conditioner which concerns on Embodiment 2. FIG.

Embodiment 1 FIG.
1 is a front view showing an outline of a heat exchanger according to Embodiment 1. FIG.
FIG. 2 is a side view showing an outline of the heat exchanger according to the first embodiment.
1 and 2, reference numeral 1 denotes a heat exchanger, which is inserted into a plurality of plate fins 2 arranged side by side at a predetermined interval and in a direction perpendicular to the plate fins 2, and is expanded (also referred to as diameter expansion). Thus, a plurality of external heat transfer tubes 31 joined to the plate-like fins 2 and a double tube 3 in which internal heat transfer tubes 32 are inserted into some of the external heat transfer tubes 31 are configured.
The plate-like fin 2 is made of a metal plate such as copper, copper alloy, aluminum, or aluminum alloy (the same applies to other embodiments), and is parallel to the air flow direction A and in the vertical direction (depth) in the figure. Direction) at a predetermined interval. In addition, the plate-like fins 2 are provided with a plurality of double tubes 3 described later in one or more rows in a direction perpendicular to the air flow direction A (vertical direction in the figure).
In the example of FIGS. 1 and 2, the double pipe 3 is formed from the lowest stage to the second stage, but the present invention is not limited to this. For example, all the heat transfer tubes may be the double tubes 3, or the range from the uppermost stage to a predetermined number of steps may be the double tubes 3. Moreover, although the example of FIG. 1, FIG. 2 demonstrates the case where 2 rows of heat exchanger tubes (external heat exchanger tube 31, double tube 3) are arrange | positioned, this invention is not limited to this, 1 row or 3 rows or more But it ’s okay.

The double tube 3 has an external heat transfer tube 31 and an internal heat transfer tube 32, a refrigerant (heat medium) flowing through a first refrigerant flow path 33 a between the external heat transfer tube 31 and the internal heat transfer tube 32, and an internal The refrigerant (heat medium) flowing through the second refrigerant flow path 33b in the heat transfer tube 32 is configured to be able to exchange heat.
A plurality of protrusions 34 are formed on the inner surface of the external heat transfer tube 31 so as to extend in the tube axis direction. The protrusion 34 has a continuous protrusion shape, and is formed such that a straight line parallel to the tube axis direction and the direction in which the protrusion 34 extends have an angle.
A plurality of partitions 33 are formed on the outer surface of the internal heat transfer tube 32 so as to extend in the tube axis direction. The partition 33 has a continuous protrusion shape, and is formed such that a straight line parallel to the tube axis direction and the direction in which the partition 33 extends have an angle.
In order to reduce the contact heat resistance between the external heat transfer tube 31 and the internal heat transfer tube 32, the internal heat transfer tube 32 is preferably expanded (also referred to as diameter expansion). The double pipe 3 is made of a metal material such as copper, copper alloy, aluminum, or aluminum alloy, and is formed of an extruded material or a drawing material (the same applies to other embodiments).

In the present embodiment, the case where the refrigerant flows as the heat medium in the first refrigerant channel 33a and the second refrigerant channel 33b will be described, but the present invention is not limited to this. For example, an arbitrary medium such as water may be used as the heat medium (the same applies to other embodiments).
In addition, the protrusion 34 in this Embodiment is corresponded to the "protrusion formed in the inner surface of an external heat exchanger tube" in this invention.
Moreover, the partition 33 in this Embodiment is corresponded to the "protrusion formed in the outer surface of an internal heat exchanger tube" in this invention.

FIG. 3 is a perspective view showing the configuration of the double pipe according to the first embodiment.
FIG. 4 is a perspective view showing an outline of the internal heat transfer tube according to the first embodiment.
As shown in FIGS. 3 and 4, the outer surface of the internal heat transfer tube 32 has a plurality of partitions having a substantially square cross section (the tip is slightly rounded) at a predetermined height and interval. 33 is provided in the axial direction. On the inner surface of the external heat transfer tube 31, a plurality of protrusions 34 are provided in the axial direction with a predetermined height and interval and a substantially square cross section (the tip is slightly rounded). .
The partition 33 and the protrusion 34 expand the heat transfer area of the inner surface of the external heat transfer tube 31 and the outer surface of the internal heat transfer tube 32. Further, the partition 33 and the protrusion 34 cause a disturbance in the flow of the refrigerant flowing through the second refrigerant flow path 33b. Thereby, there exists an effect which accelerates | stimulates the heat transfer between the refrigerant | coolant of the 1st refrigerant flow path 33a, and the 2nd refrigerant flow path 33b. Moreover, there exists an effect which accelerates | stimulates the heat transfer between the 2nd refrigerant | coolant flow path 33b and the plate-shaped fin 2. FIG.
In addition, the cross-sectional shape of the partition 33 and the protrusion 34 is not limited to a quadrilateral shape, and can be an appropriate cross-sectional shape such as a triangular shape, a trapezoidal shape, or a semicircular shape.
In addition, the partition 33 and the protrusion 34 may be formed continuously in the length direction of the heat transfer tube, or may be formed discontinuously in a part of the length direction.

FIG. 5 is a diagram schematically showing the angles of the partitions and protrusions according to the first embodiment.
As shown in FIG. 5, the angle θ1 formed by the direction in which the protrusion 34 extends and the straight line parallel to the tube axis direction are different from the angle θ2 formed by the direction in which the partition 33 extends and the straight line parallel to the tube axis direction. Is formed.
It is preferable that the angle θ1 formed by the direction in which the protrusion 34 extends and the straight line parallel to the tube axis direction is larger than the angle θ2 formed by the direction in which the partition 33 extends and the straight line parallel to the tube axis direction. This is because the residence time of the refrigerant flowing along the inner surface of the external heat transfer tube 31 is increased, and the heat transfer coefficient between the external heat transfer tube 31 and the plate-like fins 2 is improved.
For example, if the angle θ1 of the protrusion 34 and the angle θ2 of the partition 33 are the same, the refrigerant flow in the second refrigerant flow path 33b is less likely to be disturbed. As a result, heat transfer between the refrigerant in the first refrigerant flow path 33a and the second refrigerant flow path 33b and heat transfer between the second refrigerant flow path 33b and the plate-like fins 2 are performed. It becomes difficult to be accelerated, and the heat transfer performance (heat transfer performance in the pipe) decreases.

The number of protrusions 34 provided on the inner surface of the external heat transfer tube 31 is different from the number of partitions 33 provided on the outer surface of the internal heat transfer tube 32.
In addition, it is preferable that the number of protrusions 34 is larger than the number of partitions 33. This is because the amount of refrigerant retained between the protrusions 34 on the inner surface of the external heat transfer tube 31 is increased, and the heat transfer coefficient between the external heat transfer tube 31 and the plate-like fins 2 is improved.
For example, if the number of protrusions 34 and the number of partitions 33 are the same, the refrigerant flow in the second refrigerant flow path 33b is less likely to be disturbed. As a result, heat transfer between the refrigerant in the first refrigerant flow path 33a and the second refrigerant flow path 33b and heat transfer between the second refrigerant flow path 33b and the plate-like fins 2 are performed. It becomes difficult to be accelerated, and the heat transfer performance (heat transfer performance in the pipe) decreases.

FIG. 6 is a diagram showing the arrangement of the heat exchanger according to Embodiment 1 in the outdoor unit.
In FIG. 6, the case where the heat exchanger 1 mentioned above is arrange | positioned, for example in the outdoor unit of an air conditioner, is used as an outdoor heat exchanger. As shown in FIG. 6, in the heat exchanger 1 arranged in the outdoor unit, the upper region of the heat exchanger 1 (upward direction in the figure) with respect to the direction perpendicular to the air flow direction A (up and down direction in the figure). ) Or the lower region of the heat exchanger 1 (downward in the figure) is a region where the flow of air is small.
Therefore, in the present embodiment, as shown in FIGS. 1 and 2, a plurality of stages in the lower region (downward direction in the figure) with respect to the direction perpendicular to the air flow direction A (upward and downward direction in the figure). About (for example, 2 steps | paragraphs), the heat exchanger tube was comprised with the double tube 3. FIG.
The refrigerant in the external heat transfer tube 31 of the double tube 3 simultaneously performs heat exchange with the air in the plate-like fins 2 and heat exchange with the refrigerant in the internal heat transfer tube 32 to absorb heat. Thereby, the heat transfer performance in the pipe is improved in a region where the air flow is small.
In addition, although the case where the lower stage region is constituted by the double pipe 3 has been described here, the present invention is not limited to this, and the heat transfer pipes arranged in a predetermined number of stages from the uppermost stage and the predetermined number of stages from the lowermost stage. At least one of the arranged heat transfer tubes may be constituted by the double tube 3. For example, as shown in FIGS. 7 and 8, the heat transfer tube has a plurality of stages (for example, two stages) in the upper region (upward direction in the figure) with respect to the direction perpendicular to the air flow direction A (upward and downward direction in the figure). May be constituted by a double pipe 3.
In the above description, the case where a plurality of heat transfer tubes are arranged in the vertical direction has been described, but the present invention is not limited to this. A plurality of heat transfer tubes may be arranged in a plurality of stages in a direction orthogonal to the air flow direction, and the heat transfer tubes arranged in a predetermined number of stages from the endmost stage may be configured by the double pipe 3.

Next, an example of the procedure for expanding the diameter of the external heat transfer tube 31 as described above and the procedure for attaching the mounting hole (long hole) 25 provided in the plate-like fin 2 will be described.
FIG. 9 is an explanatory view of the expansion means of the heat transfer tube according to the first embodiment.
As shown in FIG. 9, the fin collar portion 24 of the pressed plate-like fin 2 is provided with a long mounting hole 25, and each plate-like fin 2 has the fin collar portion 24 aligned in the same direction. It is held with a jig. And the external heat exchanger tube 31 mentioned above is inserted in the attachment hole 25 of each plate-like fin 2, and the tube expansion bullet ball 100 is then used with the tube expansion device using the tube expansion bullet ball 100 made of a metal material such as cemented carbide. It is pushed into the external heat transfer tube 31 by a mechanical method. Then, the diameter of the external heat transfer tube 31 is increased, and the external heat transfer tube 31 is sequentially joined to each plate-like fin 2 and fixed integrally. Thereafter, the internal heat transfer tube 32 is inserted into the external heat transfer tube 31. In order to reduce the contact heat resistance between the external heat transfer tube and the internal heat transfer tube, the internal heat transfer tube is preferably expanded (also referred to as diameter expansion).

As described above, in the present embodiment, at least a part of the plurality of heat transfer tubes has the external heat transfer tubes 31 and the internal heat transfer tubes 32, and the heat flowing between the external heat transfer tubes 31 and the internal heat transfer tubes 32. The medium and the heat medium flowing through the internal heat transfer tube 32 are configured by the double tube 3 that exchanges heat. And the some protrusion 34 is formed in the inner surface of the external heat exchanger tube 31, the some partition 33 is formed in the outer surface of the internal heat exchanger tube 32, and the direction where the protrusion 34 extends, and the straight line parallel to a pipe-axis direction make | form. The angle is different from the angle formed by the direction in which the partition 33 extends and the straight line parallel to the tube axis direction.
For this reason, the heat transfer area which the refrigerant | coolant between the external heat exchanger tube 31 and the internal heat exchanger tubes 32 contacts can be increased. Further, the refrigerant flow flowing between the external heat transfer tube 31 and the internal heat transfer tube 32 can be disturbed. Therefore, there is an effect of promoting heat transfer between the refrigerant in the first refrigerant flow path 33a and the second refrigerant flow path 33b. Moreover, there exists an effect which accelerates | stimulates the heat transfer between the 2nd refrigerant | coolant flow path 33b and the plate-shaped fin 2. FIG. Therefore, the heat transfer performance of heat exchange between the medium of the external heat transfer tube 31 and the medium of the internal heat transfer tube 32 can be improved.

In the present embodiment, the number of ridges 34 and the number of partitions 33 are different. For example, the number of protrusions 34 is made larger than the number of partitions 33.
For this reason, the refrigerant | coolant amount hold | maintained between the protrusion 34 and the protrusion 34 of the inner surface of the external heat exchanger tube 31 increases, and the heat transfer rate between the external heat exchanger tube 31 and the plate-shaped fin 2 can be improved. The heat transfer performance of the heat exchanger 1 can be improved.

In the present embodiment, the angle formed by the direction in which the protrusion 34 extends and the straight line parallel to the tube axis direction is larger than the angle formed by the direction in which the partition 33 extends and a straight line parallel to the tube axis direction. .
For this reason, the residence time of the refrigerant flowing along the inner surface of the external heat transfer tube 31 is lengthened, the heat transfer rate between the external heat transfer tube 31 and the plate-like fins 2 can be improved, and the heat transfer of the heat exchanger 1 is improved. Thermal performance can be improved.

In the present embodiment, the plurality of heat transfer tubes are arranged in a plurality of stages in the vertical direction, and at least of the heat transfer tubes arranged in a predetermined number of stages from the uppermost stage and the heat transfer pipes arranged in a predetermined number of stages from the lowermost stage. One was constituted by a double tube 3.
For this reason, heat transfer performance can be improved in a region where the flow of air flowing through the plate-like fins 2 is small.
Moreover, by making some of the plurality of heat transfer tubes into the double tubes 3, the manufacturing cost can be reduced as compared with the case where all the heat transfer tubes are made into the double tubes 3.

Embodiment 2. FIG.
FIG. 10 is a diagram showing an outline of the air conditioner according to the second embodiment.
10, the air conditioner of the present embodiment includes a compressor 10, a four-way valve 11, a gas pipe 12, an indoor heat exchanger 13, a liquid pipe 14, a first expansion valve 15, a second expansion valve 16, and outdoor heat. A refrigeration cycle circuit in which the exchanger 17 is sequentially connected by piping is provided. In addition, fans 18 are provided in the vicinity of the indoor heat exchanger 13 and the outdoor heat exchanger 17, respectively.
The refrigeration cycle circuit in the present embodiment corresponds to the “refrigeration cycle apparatus” in the present invention.
Further, the first expansion valve 15 and the second expansion valve 16 in the present embodiment correspond to “expansion means” in the present invention.

The outdoor heat exchanger 17 of the refrigeration cycle circuit in the present embodiment is configured by the heat exchanger 1 using the double pipe 3 as a part of the heat transfer tube described in the first embodiment.
In the outdoor heat exchanger 17, one end of the first refrigerant flow path 33 a of the double pipe 3 is connected to the four-way valve 11, and the other end is connected to the suction side of the compressor 10. One end of the second refrigerant flow path 33 b of the double pipe 3 is connected to the first expansion valve 15, and the other end is connected to the second expansion valve 16.
In addition, as a partial area | region which arrange | positions the double tube 3 among the some heat exchanger tubes of the heat exchanger 1, the exit area | region of a condenser or the exit area | region of an evaporator is preferable. The outlet of the condenser is a single-phase region, and when the refrigerant flows through the annular portion between the external heat transfer tube 31 and the internal heat transfer tube 32, the refrigerant speed increases, the internal performance can be improved, and the heat exchange capacity can be increased. It is because the heat exchanger which can be obtained is obtained.

With such a configuration, in the heating operation, as indicated by the solid line arrow in FIG. 10, the refrigerant discharged from the compressor 10 is sent to the indoor heat exchanger 13 (condenser) via the four-way valve 11. The heat is exchanged with room air supplied by the fan 18 to be condensed. The refrigerant depressurized by the first expansion valve 15 flows through the second refrigerant flow path 33 b of the double pipe 3 of the outdoor heat exchanger 17. The degree of dryness of the refrigerant flowing through the second refrigerant flow path 33b of the double pipe 3 is reduced by exchanging heat with a low-temperature refrigerant (described later) flowing through the first refrigerant flow path 33a.
After that, the pressure is further reduced by the second expansion valve 16 and flows through the heat transfer pipe (other than the double pipe 3) of the outdoor heat exchanger 17 serving as an evaporator, through the outdoor air supplied by the fan 18 and the plate-like fins 2. Then, heat exchange is performed to evaporate and become a low-temperature and low-pressure gas refrigerant. Thereafter, the first refrigerant flow path 33a of the double pipe 3 of the outdoor heat exchanger 17 is circulated through the four-way valve 11 to exchange heat with the refrigerant flowing through the second refrigerant flow path 33b. Heat is exchanged with the outdoor air supplied through the plate-like fins 2. Thereafter, it is sucked into the compressor 10.

  In this way, during the heating operation, the refrigerant flowing out from the outlet of the outdoor heat exchanger 17 (evaporator) flows through the first refrigerant flow path 33a of the double pipe 3 and the second pipe 3 The refrigerant flowing from the outlet of the first expansion valve 15 flows through the refrigerant flow path 33b, whereby the refrigerant between the first refrigerant flow path 33b and the second refrigerant flow path 33b exchanges heat. Thereby, the dryness of the refrigerant at the inlet of the outdoor heat exchanger 17 (evaporator) is reduced, and the refrigeration cycle capacity can be improved.

In the cooling operation, as indicated by the dotted arrows in FIG. 10, the refrigerant discharged from the compressor 10 is sent to the outdoor heat exchanger 17 (condenser) via the four-way valve 11 and supplied by the fan 18. Heat is exchanged through the outdoor air and the plate-like fins 2 for condensation. Thereafter, the refrigerant decompressed by the second expansion valve 16 flows through the second refrigerant flow path 33 b of the double pipe 3 of the outdoor heat exchanger 17. The degree of dryness of the refrigerant flowing through the second refrigerant flow path 33b of the double pipe 3 is reduced by exchanging heat with a low-temperature refrigerant (described later) flowing through the first refrigerant flow path 33a.
Thereafter, the pressure is further reduced by the first expansion valve 15, flows through the indoor heat exchanger 13 serving as an evaporator, heat-evaporates by exchanging heat with the indoor air supplied by the fan 18, and low-temperature / low-pressure gas refrigerant Become. Thereafter, the first refrigerant flow path 33a of the double pipe 3 of the outdoor heat exchanger 17 is circulated through the four-way valve 11 to exchange heat with the refrigerant flowing through the second refrigerant flow path 33b. Heat is exchanged with the outdoor air supplied through the plate-like fins 2. Thereafter, it is sucked into the compressor 10.

  Thus, during the cooling operation, the refrigerant flowing out from the outlet of the indoor heat exchanger 13 (evaporator) flows through the first refrigerant flow path 33a of the double pipe 3 and the second pipe 3 The refrigerant flowing from the outlet of the outdoor heat exchanger 17 (condenser) through the second expansion valve 15 flows through the refrigerant flow path 33b, so that the space between the first refrigerant flow path 33b and the second refrigerant flow path 33b. The refrigerant exchanges heat. Thereby, the dryness of the refrigerant at the inlet of the indoor heat exchanger 13 (evaporator) is reduced, and the refrigeration cycle capacity can be improved.

As described above, in the present embodiment, the refrigerant from the outlet of the condenser is cooled by the double pipe 3 and then circulated to the evaporator.
For this reason, the dryness of the refrigerant | coolant in an evaporator inlet_port | entrance becomes small, the superheat degree of the refrigerant | coolant in an evaporator exit becomes large, and it can improve a refrigerating-cycle capability.
Further, by exchanging heat between the first refrigerant flow path 33a and the second refrigerant flow path 33b of the double pipe 3, a heat exchanger can be formed inside the heat transfer pipe. Thereby, the heat exchanger inside a heat exchanger tube and the air heat exchanger by the plate-shaped fin 2 can be integrated, and manufacturing cost can be reduced. Moreover, the volume of the heat exchanger can be reduced. A highly efficient and high density heat exchanger can be obtained.

  In this embodiment, the case where the heat exchanger 1 having the double pipe 3 is used as the outdoor heat exchanger 17 has been described. However, the present invention is not limited to this. You may make it comprise at least one of a condenser and an evaporator with the said heat exchanger 1. FIG.

  In addition, in this Embodiment, although the air conditioner which has a refrigerating cycle circuit was demonstrated, it is applicable not only to this but arbitrary apparatuses, such as a refrigerator which has said refrigeration cycle apparatus. In the refrigeration cycle circuit used in the refrigerator, the four-way valve 11 is omitted, and the heat exchanger 1 having the double pipe 3 is used as a heat exchanger that acts as an evaporator.

  In each of the above embodiments, the working fluid flowing through the heat exchanger 1 is a single HC refrigerant or a mixed refrigerant containing HC, or R32, R410A, R407C, tetrafluoropropene, and tetrafluoropropene. Also, a non-azeotropic refrigerant mixture composed of an HFC refrigerant having a low boiling point or a refrigerant such as carbon dioxide can be used.

  DESCRIPTION OF SYMBOLS 1 Heat exchanger, 2 Plate fin, 3 Double pipe, 10 Compressor, 11 Four-way valve, 12 Gas piping, 13 Indoor heat exchanger, 14 Liquid piping, 15 1st expansion valve, 16 2nd expansion valve, 17 Outdoor heat exchanger, 18 fan, 24 fin collar part, 25 mounting hole, 31 external heat transfer pipe, 32 internal heat transfer pipe, 33 partition, 33a first refrigerant flow path, 33b second refrigerant flow path, 34 ridge, 100 Expanded burette ball.

Claims (8)

A plurality of plate-like fins arranged side by side at a predetermined interval;
A plurality of heat transfer tubes inserted in a direction perpendicular to the plate fins,
At least some of the plurality of heat transfer tubes are
It has an external heat transfer tube and an internal heat transfer tube, and is constituted by a double tube that exchanges heat between a heat medium that flows between the external heat transfer tube and the internal heat transfer tube, and a heat medium that flows through the internal heat transfer tube,
On the inner surface of the external heat transfer tube, a plurality of protrusions are formed extending in the length direction,
On the outer surface of the internal heat transfer tube, a plurality of partitions that partition the flow path between the external heat transfer tube and the internal heat transfer tube are formed extending in the length direction,
An angle formed by a direction in which the protrusion formed on the inner surface of the external heat transfer tube extends and a straight line parallel to the tube axis direction, and a straight line parallel to the direction in which the partition formed on the outer surface of the internal heat transfer tube extends and the tube axis direction Unlike the angle between
The number of the projections formed on the inner surface of the outer heat transfer tubes, Many than the number of the partition formed on the outer surface of the inner heat transfer tube,
The angle formed between the direction in which the protrusions formed on the inner surface of the external heat transfer tube extend and the straight line parallel to the tube axis direction is a straight line parallel to the direction in which the partition formed on the outer surface of the internal heat transfer tube extends and the tube axis direction. A heat exchanger characterized by being larger than the angle formed by . The plurality of heat transfer tubes are arranged in a plurality of stages in a direction orthogonal to the air flow direction, and the heat transfer tubes arranged in a range of a predetermined number of stages from the endmost stage are constituted by the double pipes. 1 Symbol heat exchanger of the mounting. The plurality of heat transfer tubes are arranged in a plurality of stages in the vertical direction, and at least one of the heat transfer tubes arranged in the range of the predetermined number of stages from the uppermost stage and the heat transfer tubes arranged in the range of the predetermined number of stages from the lowermost stage, The heat exchanger according to claim 1 or 2 , wherein the heat exchanger is constituted by the double pipe. A refrigeration cycle apparatus for circulating a refrigerant by sequentially connecting a compressor, a condenser, an expansion means, and an evaporator with piping,
A refrigeration cycle apparatus, wherein at least one of the condenser and the evaporator is configured by the heat exchanger according to any one of claims 1 to 3 . A refrigeration cycle apparatus for circulating a refrigerant by sequentially connecting a compressor, a condenser, an expansion means, and an evaporator with piping,
The evaporator is constituted by the heat exchanger according to any one of claims 1 to 3 ,
The refrigerant from the outlet of the expansion means flows through the refrigerant flow path in the internal heat transfer pipe of the heat transfer pipe constituted by the double pipe,
A refrigeration cycle apparatus, wherein a refrigerant from the evaporator outlet flows through a refrigerant flow path between the external heat transfer tube and the internal heat transfer tube of the heat transfer tube constituted by the double tube. A refrigeration cycle apparatus for circulating a refrigerant by sequentially connecting a compressor, a condenser, an expansion means, and an evaporator with piping,
The condenser is constituted by the heat exchanger according to any one of claims 1 to 3 ,
The refrigerant from the condenser outlet flows through the refrigerant flow path in the internal heat transfer pipe of the heat transfer pipe constituted by the double pipe,
A refrigeration cycle apparatus, wherein a refrigerant from the evaporator outlet flows through a refrigerant flow path between the external heat transfer tube and the internal heat transfer tube of the heat transfer tube constituted by the double tube. A refrigerator comprising the refrigeration cycle apparatus according to any one of claims 4 to 6 . An air conditioner comprising the refrigeration cycle apparatus according to any one of claims 4 to 6 .

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