WO2018134975A1 - Heat exchanger, refrigeration cycle device, and method for manufacturing heat exchanger - Google Patents

Abstract

This heat exchanger is provided with: a heat transfer pipe through which an operating fluid flows; and a plurality of fins through which the heat transfer pipe is extended and which are parallelly arranged with gaps therebetween. The heat transfer pipe has a first groove formed in the inner peripheral wall of the heat transfer pipe and reduces the wall thickness of the pipe to a level less than the thickness of the inner peripheral wall; and a second groove which is formed in the inner peripheral wall of the heat transfer pipe, reduces the wall thickness of the pipe to a level less than the thickness of the inner peripheral wall, and has a different shape from the first groove.

Description

Heat exchanger, refrigeration cycle apparatus, and method of manufacturing heat exchanger

The present invention relates to a heat exchanger, a refrigeration cycle apparatus, and a heat exchanger manufacturing method in which a groove is formed in an inner peripheral wall of a heat transfer tube.

In a heat source side heat exchanger used for an air conditioner, a groove formed at the time of manufacturing the heat transfer tube is formed on the inner peripheral wall of the heat transfer tube through which the working fluid flows. This heat transfer tube is expanded using a tube expansion burette having a diameter larger than the inner diameter of the heat transfer tube in which a groove is formed in the inner peripheral wall in the manufacturing process of the heat source side heat exchanger. Thereby, the several fin arranged in the heat exchanger tube at intervals is being fixed to the expanded heat exchanger tube.

Conventionally, the manufacture of a heat exchanger in which a tube expansion burette is inserted into a heat transfer tube having a convex portion sandwiched between two spiral grooves by an inner peripheral wall and the outer diameter of the heat transfer tube is expanded over the length of the heat transfer tube. A method is known (see, for example, Patent Document 1).
In the technique of Patent Document 1, a V-shaped groove extending straight in the insertion direction is formed on the outer peripheral surface of the expanded burette. And when a pipe expansion burette is advanced in a heat exchanger tube, a part of convex part of a heat exchanger tube is formed in the processus | protrusion which protruded in radial direction rather than the convex part by the V-shaped groove | channel.
Thereby, it is supposed that the heat transfer performance (heat transfer efficiency) of a heat exchanger tube can be improved.

JP 2009-058186 A

In the technique of Patent Document 1, a liquid film of working fluid that flows along the groove is formed in the heat transfer tube of the heat source side heat exchanger. At this time, in the liquid film of the working fluid, convection heat transfer is performed and evaporation from the liquid film surface is predominantly performed. Therefore, with respect to the protrusion, there is little convective heat transfer from the heat transfer tube to the liquid film of the working fluid, and the effect of improving the heat transfer efficiency of the newly formed protrusion is limited.
In addition, the working fluid that circulates in the heat transfer tube is laminar in the low mass velocity region. Even if the working fluid becomes laminar in this way, the liquid film of the working fluid that flows along the groove inside the heat transfer tube is limited, and convective heat transfer to the liquid film of the working fluid is difficult, and heat transfer efficiency is reduced. To do.

This invention is for solving the said subject, and it aims at providing the manufacturing method of the heat exchanger which can improve the heat transfer efficiency of a heat exchanger tube, the refrigerating cycle apparatus, and a heat exchanger.

A heat exchanger according to the present invention includes a heat transfer tube through which a working fluid flows, and a plurality of fins that are inserted through the heat transfer tube and arranged in parallel at intervals, and the heat transfer tube is disposed on an inner peripheral wall. A first groove formed and made thinner in the wall than the inner wall, and a second groove formed in the inner wall and made thinner in the wall than the inner wall and having a shape different from the first groove. And a groove.

The refrigeration cycle apparatus according to the present invention includes the heat exchanger described above.

A method of manufacturing a heat exchanger according to the present invention is a method of manufacturing a heat exchanger comprising: a heat transfer tube through which a working fluid flows; and a plurality of fins that are inserted through the heat transfer tube and arranged in parallel at intervals. In the method, a first groove is formed in the inner peripheral wall of the heat transfer tube to be thinner than the inner peripheral wall at the time of manufacturing the heat transfer tube, and the inner peripheral wall of the heat transfer tube is less than the inner peripheral wall. Also, the thickness of the tube is reduced, and the second groove having a shape different from that of the first groove is formed at the time of expansion of the heat transfer tube inserted through the plurality of fins.

According to the heat exchanger, the refrigeration cycle apparatus, and the method for manufacturing a heat exchanger according to the present invention, the heat transfer tube is formed on the inner peripheral wall, and the first groove having a smaller wall thickness than the inner peripheral wall, and the inner peripheral wall It was formed, and the tube thickness was made thinner than the inner peripheral wall, and the second groove had a shape different from the first groove. Thereby, the area | region where the tube thickness of a heat exchanger tube is thin increases, and the heat-transfer area which is easy to transfer heat with a thin tube thickness can be expanded. Moreover, the unevenness | corrugation formed in the inner peripheral wall of a heat exchanger tube becomes complicated, and the turbulent flow of the working fluid which distribute | circulates a heat exchanger tube can be promoted. Therefore, the heat transfer efficiency of the heat transfer tube can be further improved.

It is a perspective view which shows the heat exchanger which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the longitudinal cross-section of the heat exchanger which concerns on Embodiment 1 of this invention. It is a figure which shows collectively the internal structure 1 of the heat exchanger tube which concerns on Embodiment 1 of this invention, FIG. 3 (a) is a figure which expand | deploys and shows the inner surface of a heat exchanger tube, FIG.3 (b) is a heat exchanger tube. It is a perspective view which shows the outline | summary of an inner surface, and FIG.3 (c) is explanatory drawing which shows the cross section which orthogonally crosses the inner surface of a heat exchanger tube to the length direction of a heat exchanger tube. It is a figure which shows collectively the internal structure 2 of the heat exchanger tube which concerns on Embodiment 1 of this invention, Fig.4 (a) is a figure which expand | deploys and shows the inner surface of a heat exchanger tube, FIG.4 (b) is a heat exchanger tube. It is a perspective view which shows the outline | summary of the inner surface of this, and FIG.4 (c) is explanatory drawing which shows the cross section which orthogonally crosses the inner surface of a heat exchanger tube to the length direction of a heat exchanger tube. It is a figure which shows collectively the internal structure 3 of the heat exchanger tube which concerns on Embodiment 1 of this invention, Fig.5 (a) is a figure which expand | deploys and shows the inner surface of a heat exchanger tube, FIG.5 (b) is a heat exchanger tube. FIG. 5C is an explanatory view showing a cross section of the inner surface of the heat transfer tube perpendicular to the length direction of the heat transfer tube. It is a figure which shows collectively the internal structure 4 of the heat exchanger tube which concerns on Embodiment 1 of this invention, FIG. 6 (a) is a figure which expand | deploys and shows the inner surface of a heat exchanger tube, FIG.6 (b) is a heat exchanger tube. FIG. 6C is an explanatory view showing a cross section of the inner surface of the heat transfer tube perpendicular to the length direction of the heat transfer tube. It is a figure which shows collectively the cross-sectional shape of the 2nd groove | channel which concerns on Embodiment 1 of this invention, FIG.7 (a) is a figure which shows the cross-sectional shape of a 2nd groove | channel of cross-sectional square shape, FIG.7 (b) FIG. 7C is a diagram showing a sectional shape of a second groove having a trapezoidal section, FIG. 7C is a diagram showing a sectional shape of a second groove having a U-shaped section, and FIG. 7D is a V-shaped section. It is a figure which shows the cross-sectional shape of this 2nd groove | channel, and FIG.7 (e) is a figure which shows the cross-sectional shape of a 2nd groove | channel with a W-shaped cross section. It is a perspective view which shows the other example of the heat exchanger which concerns on Embodiment 1 of this invention. It is a figure which shows collectively the structure of the heat exchanger tube at the time of manufacture which concerns on Embodiment 1 of this invention, Fig.9 (a) is a figure which expand | deploys and shows the inner surface of a heat exchanger tube, FIG.9 (b) is FIG. It is a perspective view which shows the outline | summary of the inner surface of a heat tube, and FIG.9 (c) is explanatory drawing which shows the cross section which orthogonally crosses the inner surface of a heat exchanger tube to the length direction of a heat exchanger tube. It is a figure which shows collectively the pipe expansion process at the time of the pipe expansion of the heat exchanger tube which concerns on Embodiment 1 of this invention, and is a figure which shows the pipe expansion process S1 which Fig.10 (a) inserts a pipe expansion burette straightly in the length direction of a heat exchanger tube. FIG. 10B is a diagram showing a tube expansion step S2 in which the tube expansion burette is inserted while being rotated with respect to the length direction of the heat transfer tube. It is a figure which shows collectively the shape of the tube expansion burette which concerns on Embodiment 1 of this invention, and is FIG. 11 (a1) is a side view which shows the tube expansion burette which has a convex part parallel to the length direction of a heat exchanger tube. 11 (a2) is a front view of the expanded burette of FIG. 11 (a1) as viewed from the tip, and FIG. 11 (b) is a side view showing the expanded burette having a spiral convex portion with respect to the length direction of the heat transfer tube. FIG. 11 (c) is a side view showing a tube expansion burette having a convex portion whose length is shorter than the width of the cross section perpendicular to the groove length direction of the second groove in the length direction of the heat transfer tube; FIG. 11D is a side view showing a tube expansion burette having a convex portion having a length shorter than the width of the cross section perpendicular to the groove length direction of the second groove in the length direction of the heat transfer tube. It is a figure which shows collectively the state of the working fluid in the heat exchanger tube which concerns on Embodiment 1 of this invention, Fig.12 (a) shows the case where the groove depth of a 1st groove | channel and the groove depth of a 2nd groove | channel are the same. FIG. 12B is a diagram illustrating a case where the groove depth of the first groove is different from the groove depth of the second groove. It is a schematic block diagram which shows the air conditioning apparatus which concerns on Embodiment 2 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In addition, in each figure, what attached | subjected the same code | symbol is the same or it corresponds, and this is common in the whole text of a specification.
Furthermore, the forms of the constituent elements shown in the entire specification are merely examples, and are not limited to these descriptions.

Embodiment 1 FIG.
[Heat exchanger]
FIG. 1 is a perspective view showing a heat exchanger 1 according to Embodiment 1 of the present invention. FIG. 2 is an explanatory view showing a longitudinal section of the heat exchanger 1 according to Embodiment 1 of the present invention.
The heat exchanger 1 shown in FIG. 1 and FIG. 2 is used for the heat source side heat exchanger 103 with which the outdoor unit of the air conditioning apparatus 100 mentioned later is equipped, for example.
As shown in FIGS. 1 and 2, the heat exchanger 1 includes a plurality of heat transfer tubes 2 through which a working fluid flows, and a plurality of fins 3 through which the plurality of heat transfer tubes 2 are inserted and arranged in parallel at intervals. And.
The plurality of fins 3 are formed with through holes 4 having fin collars 4a around them. The straight heat transfer tube 2 is inserted into the through hole 4 and the heat transfer tube 2 is expanded. As a result, the plurality of fins 3 are fixed to the heat transfer tube 2 at intervals. The heat exchanger 1 shown in FIGS. 1 and 2 is in this state.

[Internal configuration of heat transfer tube 1]
FIG. 3 is a diagram collectively showing the internal configuration 1 of the heat transfer tube 2 according to Embodiment 1 of the present invention, and FIG. 3A is a diagram showing the inner surface of the heat transfer tube 2 expanded. (B) is a perspective view which shows the outline | summary of the inner surface of the heat exchanger tube 2, FIG.3 (c) is explanatory drawing which shows the cross section which orthogonally crosses the inner surface of the heat exchanger tube 2 to the length direction of a heat exchanger tube.

On the inner surface of the heat transfer tube 2 shown in FIG. 3, there are a plurality of first grooves 6 formed on the inner peripheral wall 5 and made thinner than the inner peripheral wall 5.
In addition, the inner surface of the heat exchanger tube 2 means the whole surface including the unevenness | corrugation inside the heat exchanger tube 2 as wording. The inner peripheral wall 5 of the heat transfer tube 2 refers to an inner peripheral reference surface that the cylindrical heat transfer tube 2 inherently has as an inner diameter.

The plurality of first grooves 6 are formed in a spiral shape with respect to the length direction of the heat transfer tube 2. The plurality of first grooves 6 are formed at an equal pitch. The plurality of first grooves 6 are formed when the heat transfer tube 2 is manufactured.
The plurality of first grooves 6 are not necessarily limited to the spiral shape shown in FIG. The plurality of first grooves 6 may be formed in a range of 0 ° <θ1 <90 ° with respect to an orthogonal plane orthogonal to the length direction of the heat transfer tube 2. Further, the plurality of first grooves 6 may be formed straight in the length direction of the heat transfer tube 2.

On the inner surface of the heat transfer tube 2, a plurality of second grooves 7 are formed on the inner peripheral wall 5, which are thinner than the inner peripheral wall 5 and have a shape different from that of the plurality of first grooves 6. .
The plurality of second grooves 7 are formed in inner surface portions different from the plurality of first grooves 6 so as to intersect the plurality of first grooves 6. The plurality of second grooves 7 are formed in a straight line parallel to the length direction of the heat transfer tube 2. The plurality of second grooves 7 are formed at an equal pitch. The plurality of second grooves 7 are formed when the heat transfer tubes 2 inserted through the plurality of fins 3 are expanded. The plurality of second grooves 7 have the same shape.
Note that the groove depth of the first groove 6 and the groove depth of the second groove 7 are preferably matched. The groove depth of the second groove 7 may be a depth different from the groove depth of the first groove 6.

[Internal structure of heat transfer tube 2]
4 is a diagram collectively showing the internal configuration 2 of the heat transfer tube 2 according to Embodiment 1 of the present invention, and FIG. 4A is a diagram showing the inner surface of the heat transfer tube 2 expanded. (B) is a perspective view which shows the outline | summary of the inner surface of the heat exchanger tube 2, and FIG.4 (c) is explanatory drawing which shows the cross section orthogonal to the length direction of a heat exchanger tube at the inner surface of a heat exchanger tube.
Here, in the internal configuration 2 of the heat transfer tube 2, features that are different from the internal configuration 1 of the heat transfer tube 2 will be described, and the same configuration will be omitted.

As shown in FIG. 4, the plurality of second grooves 7a and 7b have different shapes. Thus, the heat exchanger tube 2 may have a plurality of types of second grooves 7a and 7b by combining two or more shapes of the second grooves 7a and 7b.

[Internal configuration of heat transfer tube 3]
FIG. 5 is a diagram collectively showing the internal configuration 3 of the heat transfer tube 2 according to Embodiment 1 of the present invention, and FIG. 5A is a diagram showing the inner surface of the heat transfer tube 2 expanded. FIG. 5B is a perspective view showing an outline of the inner surface of the heat transfer tube 2, and FIG. 5C is an explanatory view showing a cross section of the inner surface of the heat transfer tube 2 orthogonal to the length direction of the heat transfer tube 2.
Here, in the internal configuration 3 of the heat transfer tube 2, features that are different from the internal configurations 1 and 2 of the heat transfer tube 2 will be described, and the same configuration will be omitted.

As shown in FIG. 5, the plurality of second grooves 7 c are formed in a spiral shape with respect to the length direction of the heat transfer tube 2. The plurality of spiral second grooves 7 c intersect the plurality of spiral first grooves 6. The plurality of spiral second grooves 7c may be formed in a range of 90 ° <θ2 <180 ° with respect to an orthogonal plane orthogonal to the length direction of the heat transfer tube 2. Accordingly, the plurality of second grooves 7 c can be formed so as to intersect perpendicularly with respect to the plurality of first grooves 6.
When the second groove 7c is provided, the heat transfer efficiency of the heat transfer tube 2 can be further improved by vigorously mixing the working fluid flowing through the first groove 6 and the second groove 7c in the heat transfer tube 2.

[Internal structure of heat transfer tube 4]
6 is a diagram collectively showing the internal configuration 4 of the heat transfer tube 2 according to Embodiment 1 of the present invention, and FIG. 6A is a diagram showing the inner surface of the heat transfer tube 2 in an exploded manner. FIG. 6B is a perspective view showing an outline of the inner surface of the heat transfer tube 2, and FIG. 6C is an explanatory view showing a cross section of the inner surface of the heat transfer tube 2 perpendicular to the length direction of the heat transfer tube 2.
Here, in the internal configuration 4 of the heat transfer tube 2, characteristic portions different from the internal configurations 1 to 3 of the heat transfer tube 2 will be described, and the same configuration will be omitted.

As shown in FIG. 6, the plurality of second grooves 7 d are parallel to the plurality of first grooves 6. That is, the plurality of second grooves 7 d are formed in a spiral shape in parallel with the plurality of first grooves 6 formed in a spiral shape in the length direction of the heat transfer tube 2. The plurality of second grooves 7d are formed in a range of 0 ° <θ1 <90 ° with respect to the orthogonal plane orthogonal to the length direction of the heat transfer tube 2, and the angle θ1 is equal to the angle θ1 of the plurality of first grooves 6. Match. The plurality of second grooves 7 d are formed at equal intervals in accordance with the intervals between the plurality of first grooves 6.
Although not shown, the plurality of second grooves may be formed in parallel to the plurality of linear first grooves 6 parallel to the length direction of the heat transfer tube 2. In this case, the plurality of second grooves are formed in a straight line parallel to the length direction of the heat transfer tube 2.

[Cross-sectional shape of second groove]
FIG. 7 is a view collectively showing the cross-sectional shape of the second groove 7 according to Embodiment 1 of the present invention, and FIG. 7A is a view showing the cross-sectional shape of the second groove 7 having a square cross section. FIG. 7B is a diagram showing a sectional shape of the second groove 7 having a trapezoidal section, and FIG. 7C is a diagram showing a sectional shape of the second groove 7 having a U-shaped section. (D) is a figure which shows the cross-sectional shape of the 2nd groove | channel 7 with a V-shaped cross section, and FIG.7 (e) is a figure which shows the cross-sectional shape of the 2nd groove | channel 7 with a W-shaped cross section.
Here, the second groove 7 of the internal configuration 1 of the heat transfer tube 2 will be described as a representative. However, these shapes may be applied to the other second grooves 7a, 7b, 7c, and 7d.

As shown in FIG. 7A, the plurality of second grooves 7 may be formed in a cross-sectional square shape in a cross-sectional shape orthogonal to the length direction. In the square shape in the second groove 7, the groove opening width 8 and the groove bottom width 9 are equal in length. In this case, the region where the tube thickness is thinner than the inner peripheral wall 5 in the heat transfer tube 2 can be increased. Moreover, the unevenness | corrugation formed in the inner peripheral wall 5 of the heat exchanger tube 2 can be complicated.

As shown in FIG. 7B, the plurality of second grooves 7 may be formed in a trapezoidal cross-sectional shape perpendicular to the length direction. In the trapezoidal cross section of the second groove 7, the groove opening width 8 and the groove bottom width 9 are different lengths. That is, in FIG. 7B, the groove bottom width 9 of the second groove 7 is longer than the groove opening width 8. In this case, the speed of the working fluid flowing through the groove bottom 10 of the second groove 7 is increased, and the heat transfer efficiency of the heat transfer tube 2 can be further improved.

Also, contrary to FIG. 7B, the plurality of second grooves 7 may be formed in a trapezoidal cross-sectional shape perpendicular to the length direction. In the trapezoidal cross section of the second groove 7, the groove opening width 8 and the groove bottom width 9 are different lengths. That is, although not shown, the groove bottom width 9 of the second groove 7 may be formed to be shorter than the groove opening width 8. In this case, when the working fluid flowing in the heat transfer tube 2 flows into the second groove 7, the contact efficiency with the heat transfer surface of the heat transfer tube 2 can be improved, and the heat transfer efficiency of the heat transfer tube 2 can be further improved.

As shown in FIG. 7C, the plurality of second grooves 7 may be formed in a U-shaped cross section in a cross-sectional shape orthogonal to the length direction. In the U-shaped cross section of the second groove 7, the groove bottom 10 is a curved surface. That is, the groove bottom width 9 of the second groove 7 is formed in a cross-sectional arc shape with a thinner groove thickness toward the center. In this case, an increase in pressure loss to the working fluid flowing through the second groove 7 is suppressed.

As shown in FIG. 7D, the plurality of second grooves 7 may be formed in a V-shaped cross section in a cross-sectional shape orthogonal to the length direction. In the V-shaped cross section of the second groove 7, the groove bottom 10 has no width. In this case, when the working fluid flowing in the heat transfer tube 2 flows into the second groove 7, the contact efficiency with the heat transfer surface of the heat transfer tube 2 can be improved, and the heat transfer efficiency of the heat transfer tube 2 can be further improved.

As shown in FIG.7 (e), the some 2nd groove | channel 7 may be formed in the cross-sectional shape orthogonal to the length direction in cross-sectional W shape. In the W-shaped cross section of the second groove 7, one mountain shape parallel to the groove length direction is formed at the groove bottom 10. In this case, when the working fluid flowing in the heat transfer tube 2 flows into the second groove 7, the contact efficiency with the heat transfer surface of the heat transfer tube 2 can be improved, and the heat transfer efficiency of the heat transfer tube 2 can be further improved.
The plurality of second grooves 7 may be formed in the groove bottom 10 with two or more mountain shapes parallel to the groove length direction. In this case, the same effect as described above can be obtained.

[Other examples of heat exchangers]
FIG. 8 is a perspective view showing another example of the heat exchanger 1 according to Embodiment 1 of the present invention. The different types of heat transfer tubes 2a and 2b in which different types of hatching in the region of the heat transfer tubes 2a and 2b shown in FIG. 8 form different types of first grooves 6 and second grooves 7 are shown.
As shown in FIG. 8, two or more different types of heat transfer tubes 2 a and 2 b in which different types of first grooves 6 and second grooves 7 are formed in one heat exchanger 1 may be used. Further, like the internal configuration 2 of the heat transfer tube 2 shown in FIG. 4, the plurality of second grooves 7 a and 7 b of one heat transfer tube 2 may have different shapes.
In this case, heat transfer tubes 2a and 2b effective for individual working fluids having different properties can be arranged. Alternatively, effective heat transfer tubes 2a and 2b can be arranged in accordance with changes in the state of the working fluid. Therefore, the heat transfer efficiency of the heat transfer tubes 2a and 2b can be further improved.

[Configuration of heat transfer tube during manufacturing]
FIG. 9 is a diagram collectively showing the configuration of the heat transfer tube 2 during manufacture according to Embodiment 1 of the present invention, and FIG. 9A is a diagram showing the inner surface of the heat transfer tube 2 in an exploded manner. 9 (b) is a perspective view showing an outline of the inner surface of the heat transfer tube 2, and FIG. 9 (c) is an explanatory view showing a cross section of the inner surface of the heat transfer tube 2 perpendicular to the length direction of the heat transfer tube 2. FIG.

As shown in FIG. 9, the heat transfer tube 2 has a plurality of first grooves 6 formed on the inner surface at the time of manufacture. The plurality of first grooves 6 may be integrally formed when the heat transfer tube 2 is formed. That is, the plurality of first grooves 6 are simultaneously formed in the manufacturing process when the heat transfer tube 2 is manufactured.

[Explanation when expanding the heat transfer tube]
FIG. 10 is a diagram collectively showing tube expansion steps S1 and S2 when the heat transfer tube 2 according to Embodiment 1 of the present invention is expanded. FIG. 10 (a) shows the tube expansion burette 11a in the length direction of the heat transfer tube 2. FIG. 10B is a diagram showing a tube expansion step S2 in which the tube expansion bullet 11b is inserted while rotating in the length direction of the heat transfer tube 2;

As shown in FIG. 10 (a), in order to fix the plurality of fins 3 arranged at intervals with respect to the plurality of heat transfer tubes 2 to the heat transfer tube 2 that has been expanded, the tube expansion burette 11 a is made longer than the length of the heat transfer tube 2. The heat transfer tube 2 is expanded by inserting it straight forward. The step of expanding the heat transfer tube 2 by inserting the tube expansion bullet 11a straightly in the length direction of the heat transfer tube 2 and inserting the same is referred to as a tube expansion step S1.
In the tube expansion step S1, the tube expansion burette 11a has a plurality of convex portions 12a parallel to the length direction of the heat transfer tube 2, as will be described later. For this reason, the plurality of second grooves 7 are inserted into the plurality of second grooves 7 straightly in the length direction of the heat transfer tube 2 by inserting the tube expansion burette 11 a having a plurality of convex portions 12 a parallel to the length direction of the heat transfer tube 2. It is formed on the locus of the convex portion 12a. In this case, the plurality of second grooves 7 are formed in a straight line parallel to the length direction of the heat transfer tube 2. Further, in this case, when the first groove 6 and the second groove 7 are intersected and formed so that the groove depth of the first groove 6 and the groove depth of the second groove 7 coincide with each other, the plurality of second grooves 7 are formed. The inner peripheral wall 5 portion of the heat transfer tube 2 protruding between the first grooves 6 can be formed to be scraped off, which is easy to manufacture.

As shown in FIG. 10 (b), in order to fix the plurality of fins 3 arranged at intervals with respect to the plurality of heat transfer tubes 2 to the heat transfer tube 2 that has been expanded, the tube expansion burette 11 b is formed in the length of the heat transfer tube 2. The heat transfer tube 2 is expanded by inserting while rotating with respect to the vertical direction. The step of expanding the heat transfer tube 2 by inserting the tube expansion bullet 11b while rotating the heat transfer tube 2 in the longitudinal direction is referred to as a tube expansion step S2.
In the tube expansion step S2, the tube expansion burette 11b has a plurality of convex portions 12b that are spiral with respect to the length direction of the heat transfer tube 2, as will be described later. For this reason, the plurality of second grooves 7c or the second grooves 7d in the tube expansion step S2 are changed from the length of the heat transfer tube 2 to the tube expansion burette 11b having the plurality of convex portions 12b spiral to the length direction of the heat transfer tube 2. It is inserted along the plurality of convex portions 12b that are spiral with respect to the vertical direction and is formed on the locus of the plurality of convex portions 12b. In this case, the plurality of second grooves 7 c or the second grooves 7 d are formed in a spiral shape with respect to the length direction of the heat transfer tube 2. In this case, if the first groove 6 and the second groove 7c are crossed and formed so that the groove depth of the first groove 6 and the groove depth of the second groove 7c coincide with each other, a plurality of second grooves 7c are formed. The inner peripheral wall 5 portion of the heat transfer tube 2 protruding between the first grooves 6 can be formed to be scraped off, which is easy to manufacture.

Here, as will be described later, the expanded burette 11c has a plurality of convex portions 12c having a length shorter than the width of the cross section perpendicular to the groove length direction of the second groove 7 in the length direction of the heat transfer tube 2. good. In this case, the tube expansion step S1 and the tube expansion step S2 can be selected using one type of tube expansion burette 11c. For this reason, it is not necessary to prepare a plurality of types of expanded burettes 11c, which is efficient.

[Shape of expanded burette]
FIG. 11 is a diagram collectively showing the shapes of the expanded burettes 11 a, 11 b, 11 c, and 11 d according to Embodiment 1 of the present invention, and FIG. 11 (a 1) is a protrusion that is parallel to the length direction of the heat transfer tube 2. 11A is a side view showing the expanded burette 11a having 12a, FIG. 11A2 is a front view of the expanded burette 11a of FIG. 11A1, viewed from the tip, and FIG. 11B is the length of the heat transfer tube 2. It is a side view which shows the pipe expansion burette 11b which has the helical convex part 12b with respect to the direction, FIG.11 (c) is a cross section orthogonal to the groove length direction of the 2nd groove | channel 7 in the length direction of the heat exchanger tube 2. FIG. 11B is a side view showing the expanded burette 11c having a convex portion 12c that is shorter than the width, and FIG. 11D is a cross-sectional view perpendicular to the length direction of the second groove 7 in the length direction of the heat transfer tube 2; Expanded bure having a convex portion 12d having a length shorter than the width in a spiral shape Is a side view showing the door 11d.

The expanded burettes 11a, 11b, 11c, and 11d as shown in Fig. 11 are used when expanding the heat transfer tube 2 having the first groove 6. By inserting the expanded burettes 11a, 11b, 11c, and 11d having an outer shape larger than the inner diameter of the heat transfer tube 2 into the heat transfer tube 2, the tube diameter of the heat transfer tube 2 is increased, and the heat transfer tube 2 is inserted into the through hole 4. The fin 3 having the fin collar 4 a over the entire circumference is fixed to the outside of the heat transfer tube 2.

The expanded burette 11a as shown in FIG. 11 (a) has a plurality of convex portions 12a parallel to the length direction of the heat transfer tube 2 on the side surface. The pipe expansion burette 11a is used in the pipe expansion process S1 described above, and at the time of pipe expansion, a plurality of linear second grooves 7 parallel to the length direction of the heat transfer pipe 2 are formed in the heat transfer pipe 2 by the trajectories of the plurality of convex portions 12a. To do.
Note that the expanded burette 11a may have different shapes of the plurality of second grooves 7a or second grooves 7b formed by changing the shapes of the plurality of convex portions 12a.

The expanded burette 11b as shown in FIG. 11 (b) has a plurality of convex portions 12b that are spiral with respect to the length direction of the heat transfer tube 2 on the side surface. The pipe expansion burette 11b is used in the pipe expansion process S2 described above, and the pipes are expanded to the heat transfer pipe 2 at the time of pipe expansion by the plurality of second grooves 7c spirally with respect to the length direction of the heat transfer pipe 2 by the trajectories of the plurality of convex portions 12b. Two grooves 7d are formed.
In addition, the tube expansion bullet 11b may vary the shape of the plurality of second grooves 7d to be formed by varying the shape of the plurality of convex portions 12b.

The expanded burette 11c as shown in FIG. 11C has a plurality of convex portions 12c whose length is shorter than the width of the cross section perpendicular to the groove length direction of the second groove 7 in the length direction of the heat transfer tube 2 on the side surface. have. When the pipe expansion burette 11c is used in the above-mentioned pipe expansion process S1, a plurality of linear second grooves 7, 7a, 7b are formed in the heat transfer tube 2 by the trajectories of the plurality of convex portions 12c during the pipe expansion. When used in the above-described tube expansion step S2, the tube expansion burette 11c forms a plurality of spiral second grooves 7c or second grooves 7d in the heat transfer tube 2 by the trajectories of the plurality of convex portions 12c during tube expansion.
In addition, the tube expansion bullet 11c may vary the shape of the plurality of second grooves 7 to be formed by varying the shape of the plurality of convex portions 12c.

The expanded burette 11d as shown in FIG. 11 (d) spirals a plurality of convex portions 12d having a length shorter than the width of the cross section perpendicular to the groove length direction of the second groove 7 in the length direction of the heat transfer tube 2. It has a shape. In this case, it can be used similarly to the expanded burette 11c as shown in FIG.

[Description of working fluid in heat transfer tube]
FIG. 12 is a diagram collectively showing the state of the working fluid in the heat transfer tube 2 according to Embodiment 1 of the present invention. FIG. 12 (a) shows the groove depth of the first groove 6 and the groove of the second groove 7. It is a figure which shows the case where the depth is the same, FIG.12 (b) is a figure which shows the case where the groove depth of the 1st groove | channel 6 and the groove depth of the 2nd groove | channel 7 differ.

Generally, the working fluid that receives heat in the heat transfer tube 2 is in the state of an annular flow or an annular spray flow that has a high heat transfer coefficient. In the heat transfer tube 2, a liquid film 13 that flows along the heat transfer surface that is the inner surface of the heat transfer tube 2 is formed. In the liquid film 13, convection heat transfer is performed, and evaporation from the liquid film surface is predominantly performed. The gas 14 that has evaporated by receiving heat from the working fluid flows through the center of the heat transfer tube 2.

As shown in FIGS. 12A and 12B, when the groove depth of the first groove 6 and the groove depth of the second groove 7 are the same, the groove depth of the first groove 6 and the second groove 7 There are cases where the groove depth is different. However, in any heat transfer tube 2, the plurality of first grooves 6 and the plurality of second grooves 7 are thinner than the inner peripheral wall 5 of the heat transfer tube 2. That is, a plurality of first grooves 6 and a plurality of second grooves 7 are formed in the heat transfer tube 2, and an area where the tube thickness is thinner than the inner peripheral wall 5 increases, and the liquid film 13 and the heat transfer tube 2 are in contact with each other. Increases area. For this reason, in the heat transfer tube 2, the heat transfer area where heat transfer is easy with a thin tube thickness that is easy to contact the liquid film 13 can be expanded. Therefore, the heat transfer efficiency of the heat transfer tube 2 can be further improved.

Further, as shown in FIGS. 3 to 6, the plurality of first grooves 6 and the plurality of second grooves 7 form the inner surface of the heat transfer tube 2 in a complicated unevenness. Therefore, the unevenness formed on the inner peripheral wall 5 on the inner surface of the heat transfer tube 2 is complicated, and the turbulent flow of the working fluid flowing through the heat transfer tube 2 can be promoted. Therefore, the heat transfer efficiency of the heat transfer tube 2 can be further improved.

In the first embodiment, the working fluid is an HFO refrigerant, an HFC refrigerant, a natural refrigerant represented by R1234yf, R1234ze, CO ₂ or the like, or a mixed refrigerant thereof.
In addition, in FIG. 12, about the two-phase fluid of the working fluid in the heat exchanger tube 2, the single refrigerant | coolant or the azeotropic mixed refrigerant | coolant was simulated as an example. However, the same effect can be obtained even in a non-azeotropic refrigerant mixture.

[Effect of Embodiment 1]
According to the first embodiment, the heat exchanger 1 includes the heat transfer tube 2 through which the working fluid flows. The heat exchanger 1 includes a plurality of fins 3 through which heat transfer tubes 2 are inserted and arranged in parallel at intervals. The heat transfer tube 2 has a first groove 6 that is formed in the inner peripheral wall 5 and has a thinner tube thickness than the inner peripheral wall 5. The heat transfer tube 2 has second grooves 7, 7 a, 7 b, 7 c, and 7 d that are formed on the inner peripheral wall 5 and are thinner than the inner peripheral wall 5 and have shapes different from those of the first groove 6. Yes.
According to this structure, the area | region where pipe | tube thickness is thinner than the inner peripheral wall 5 in the heat exchanger tube 2 increases, and the heat transfer area which is easy to transfer heat with thin pipe | tube thickness can be expanded. Moreover, the unevenness | corrugation formed in the inner peripheral wall 5 of the heat exchanger tube 2 becomes complicated, and the turbulent flow of the working fluid which distribute | circulates the heat exchanger tube 2 can be accelerated | stimulated. Therefore, the heat transfer efficiency of the heat transfer tube 2 can be further improved.

According to the first embodiment, the first groove 6 is formed when the heat transfer tube 2 is manufactured. The second grooves 7, 7 a, 7 b, 7 c, 7 d are formed when the heat transfer tube 2 inserted through the plurality of fins 3 is expanded.
According to this configuration, the first groove 6 and the second grooves 7, 7 a, 7 b, 7 c, and 7 d different from the first groove 6 exchange heat with the inner peripheral wall 5 of the heat transfer tube 2. The heat transfer tube manufacturing process and the heat transfer pipe expanding process, which are two manufacturing processes essential to the vessel 1, can be formed. For this reason, the manufacturing process for forming only the groove is not required, and the heat exchanger 1 in which the first groove 6 and the second grooves 7, 7a, 7b, 7c, and 7d are formed can be easily manufactured, and the manufacturing efficiency can be improved. Is good.

According to the first embodiment, the groove depth of the first groove 6 and the groove depths of the second grooves 7, 7a, 7b, and 7c coincide with each other.
According to this configuration, particularly when the first groove 6 and the second grooves 7, 7 a, 7 b, 7 c are formed so as to intersect with each other, the plurality of second grooves 7, 7 a, 7 b, 7 c are formed in the first groove 6. The inner peripheral wall 5 portion of the heat transfer tube 2 protruding in between can be formed to be scraped off, which is easy to manufacture.

According to the first embodiment, the second grooves 7, 7 a, 7 b, 7 c are formed so as to intersect the first groove 6.
According to this structure, the area | region where pipe | tube thickness is thinner than the inner peripheral wall 5 in the heat exchanger tube 2 can be increased. Moreover, the unevenness | corrugation formed in the inner peripheral wall 5 of the heat exchanger tube 2 can be complicated.
In addition, since the second grooves 7, 7 a, 7 b, and 7 c intersect the first groove 6, the working fluid that flows through the first groove 6 and the second grooves 7, 7 a, 7 b, and 7 c in the heat transfer tube 2. Are mixed with each other, and the heat transfer efficiency of the heat transfer tube 2 can be further improved.

According to the first embodiment, the second groove 7 d is formed in parallel to the first groove 6.
According to this structure, the area | region where pipe | tube thickness is thinner than the inner peripheral wall 5 in the heat exchanger tube 2 can be increased. Moreover, the unevenness | corrugation formed in the inner peripheral wall 5 of the heat exchanger tube 2 can be complicated.

According to the first embodiment, a plurality of second grooves 7, 7c, 7d are formed. The plurality of second grooves 7, 7c, 7d have the same shape.
According to this configuration, the second grooves 7, 7c, 7d can be easily and efficiently formed.
Further, the second grooves 7, 7c and 7d effective for individual working fluids having different properties can be selected. Alternatively, the effective second grooves 7, 7c, 7d can be selected according to the change in the state of the working fluid. Therefore, the heat transfer efficiency of the heat transfer tube 2 can be further improved.

According to the first embodiment, a plurality of second grooves 7a and 7b are formed. The plurality of second grooves 7a and 7b have different shapes.
According to this configuration, the unevenness formed on the inner peripheral wall 5 of the heat transfer tube 2 can be made more complicated.
Further, the second grooves 7a and 7b effective for individual working fluids having different properties can be arranged. Alternatively, effective second grooves 7a and 7b can be arranged in accordance with a change in the state of the working fluid. Therefore, the heat transfer efficiency of the heat transfer tube 2 can be further improved.

According to the first embodiment, the second grooves 7, 7 a, 7 b are formed in a straight line parallel to the length direction of the heat transfer tube 2.
According to this configuration, the second grooves 7, 7a, 7b can be easily and efficiently formed.
Further, the second grooves 7, 7a, 7b are linear in parallel to the length direction of the heat transfer tube 2, and extend in the working fluid flow direction. As a result, the increase in pressure loss is suppressed without hindering the flow of the working fluid.

According to the first embodiment, the second grooves 7, 7 a, 7 b are formed by straightly inserting the expanded burette 11 a having the convex portion 12 a parallel to the length direction of the heat transfer tube 2 in the length direction of the heat transfer tube 2. Has been.
According to this configuration, the second grooves 7, 7a, 7b can be easily and efficiently formed.

According to the first embodiment, the second grooves 7 c and 7 d are formed in a spiral shape with respect to the length direction of the heat transfer tube 2.
According to this configuration, the unevenness formed on the inner peripheral wall 5 of the heat transfer tube 2 can be made more complicated.
Further, for example, the spiral second grooves 7 c and 7 d can be formed in the spiral first groove 6 in the orthogonal direction. In this case, the working fluid flowing through the first groove 6 and the second grooves 7c and 7d in the heat transfer tube 2 is vigorously mixed, and the heat transfer efficiency of the heat transfer tube 2 can be further improved.

According to the first embodiment, the second grooves 7 c and 7 d are formed so that the expanded burette 11 b having the spiral convex portion 12 b with respect to the length direction of the heat transfer tube 2 is spiral with respect to the length direction of the heat transfer tube 2. It is formed by being inserted while being rotated along the convex portion 12b.
According to this configuration, the unevenness formed on the inner peripheral wall 5 of the heat transfer tube 2 can be made more complicated.

According to the first embodiment, the second groove 7 is a convex portion 12c having a length shorter than the width of the cross section perpendicular to the groove length direction of the second grooves 7, 7a, 7b in the length direction of the heat transfer tube 2. An expanded burette 11 c having a straight line is formed by straight insertion in the length direction of the heat transfer tube 2. Alternatively, the second grooves 7 c and 7 d are formed by inserting a tube expansion burette 11 c having a convex portion 12 c having a short length in the length direction of the heat transfer tube 2 while rotating it in the length direction of the heat transfer tube 2. Yes.
According to this configuration, the second grooves 7, 7 a, 7 b, 7 c, and 7 d are linear grooves parallel to the length direction of the heat transfer tube 2 or the length of the heat transfer tube 2 using one type of expanded burette 11 c. It can be formed in one of two types of grooves called spiral grooves with respect to the vertical direction. For this reason, it is not necessary to prepare a plurality of types of expanded burettes 11c, which is efficient.

According to the first embodiment, the protrusions 12a, 12b, 12c, and 12d have cross sections orthogonal to the insertion direction of the tube expansion bullets 11a, 11b, 11c, and 11d in the second grooves 7, 7a, 7b, 7c, and 7d. Equal to the cross section perpendicular to the groove length direction.
According to this configuration, the shapes of the second grooves 7, 7a, 7b, 7c, 7d can be changed according to the shapes of the convex portions 12a, 12b, 12c, 12d.

According to the first embodiment, the second groove 7 has a length equal to the groove opening width 8 and the groove bottom width 9.
According to this structure, the area | region where pipe | tube thickness is thinner than the inner peripheral wall 5 in the heat exchanger tube 2 can be increased. Moreover, the unevenness | corrugation formed in the inner peripheral wall 5 of the heat exchanger tube 2 can be complicated.

According to the first embodiment, the second groove 7 has a length in which the groove opening width 8 and the groove bottom width 9 are different.
According to this structure, the area | region where pipe | tube thickness is thinner than the inner peripheral wall 5 in the heat exchanger tube 2 can be increased. Moreover, the unevenness | corrugation formed in the inner peripheral wall 5 of the heat exchanger tube 2 can be complicated.
Further, for example, the groove bottom width 9 of the second groove 7 can be formed to be longer than the groove opening width 8. In this case, the speed of the working fluid flowing through the groove bottom 10 is increased, and the heat transfer efficiency of the heat transfer tube 2 can be further improved.
For example, the groove bottom width 9 of the second groove 7 can be formed to be shorter than the groove opening width 8. In this case, when the working fluid flowing in the heat transfer tube 2 flows into the second groove 7, the contact efficiency with the heat transfer surface of the heat transfer tube 2 can be improved, and the heat transfer efficiency of the heat transfer tube 2 can be further improved.

According to Embodiment 1, as for the 2nd groove | channel 7, the groove bottom part 10 is a curved surface.
According to this structure, the area | region where pipe | tube thickness is thinner than the inner peripheral wall 5 in the heat exchanger tube 2 can be increased. Moreover, the unevenness | corrugation formed in the inner peripheral wall 5 of the heat exchanger tube 2 can be complicated.
Also, for example, the groove bottom width 9 of the second groove 7 can be formed in a circular arc shape with a thinner groove thickness toward the center. In this case, an increase in pressure loss to the working fluid flowing through the second groove 7 is suppressed.

According to Embodiment 1, as for the 2nd groove | channel 7, the groove bottom part 10 does not have a width | variety, and the cross section orthogonal to a groove | channel length direction is V-shaped.
According to this structure, the area | region where pipe | tube thickness is thinner than the inner peripheral wall 5 in the heat exchanger tube 2 can be increased. Moreover, the unevenness | corrugation formed in the inner peripheral wall 5 of the heat exchanger tube 2 can be complicated.
Further, when the working fluid flowing in the heat transfer tube 2 flows into the second groove 7, the contact efficiency with the heat transfer surface of the heat transfer tube 2 can be improved, and the heat transfer efficiency of the heat transfer tube 2 can be further improved.

According to the first embodiment, the second groove 7 is formed in the groove bottom portion 10 in a mountain shape parallel to the groove length direction.
According to this structure, the area | region where pipe | tube thickness is thinner than the inner peripheral wall 5 in the heat exchanger tube 2 can be increased. Moreover, the unevenness | corrugation formed in the inner peripheral wall 5 of the heat exchanger tube 2 can be complicated.
Further, when the working fluid flowing in the heat transfer tube 2 flows into the second groove 7, the contact efficiency with the heat transfer surface of the heat transfer tube 2 can be improved, and the heat transfer efficiency of the heat transfer tube 2 can be further improved.

According to the first embodiment, the working fluid is an HFO refrigerant, an HFC refrigerant, a natural refrigerant, or a mixed refrigerant thereof.
According to this configuration, the working fluid has good heat transfer efficiency from the heat transfer tube 2.

According to the first embodiment, the method of manufacturing the heat exchanger 1 includes a heat transfer tube 2 through which a working fluid flows, and a plurality of fins 3 that are inserted through the heat transfer tube 2 and arranged in parallel at intervals. The provided heat exchanger 1 is manufactured. A first groove 6 is formed in the inner peripheral wall 5 of the heat transfer tube 2 to make the tube thickness thinner than the inner peripheral wall 5 when the heat transfer tube 2 is manufactured. Unlike the first groove 6, the second grooves 7, 7 a, 7 b, 7 c, and 7 d that are thinner than the inner peripheral wall 5 in the inner peripheral wall 5 of the heat transfer tube 2 are inserted into the plurality of fins 3. It is formed when the heat pipe 2 is expanded.
According to this configuration, the first groove 6 and the second grooves 7, 7 a, 7 b, 7 c, and 7 d different from the first groove 6 exchange heat with the inner peripheral wall 5 of the heat transfer tube 2. It can be divided into two essential manufacturing steps of the vessel 1. For this reason, the manufacturing process for forming only the groove is not required, and the heat exchanger 1 in which the first groove 6 and the second grooves 7, 7a, 7b, 7c, and 7d are formed can be easily manufactured, and the manufacturing efficiency can be improved. Is good.

According to the first embodiment, the second grooves 7, 7 a, 7 b formed when the heat transfer tube 2 is expanded have the expanded burette 11 a having the convex portions 12 a parallel to the length direction of the heat transfer tube 2 of the heat transfer tube 2. It is formed by inserting straight in the length direction.
According to this configuration, the second grooves 7, 7a, 7b can be easily and efficiently formed.

According to the first embodiment, the second grooves 7 c and 7 d formed when the heat transfer tube 2 is expanded include the expanded burette 11 b having the spiral convex portion 12 b with respect to the length direction of the heat transfer tube 2. It is formed by being inserted while rotating along the spiral convex portion 12b with respect to the length direction.
According to this configuration, the unevenness formed on the inner peripheral wall 5 of the heat transfer tube 2 can be made more complicated.

According to the first embodiment, the second groove 7 formed when the heat transfer tube 2 is expanded has a cross-sectional width orthogonal to the length direction of the second grooves 7, 7 a and 7 b in the length direction of the heat transfer tube 2. Further, the expanded pipe burette 11 c having the convex portion 12 c having a shorter length is inserted straight in the length direction of the heat transfer tube 2. Alternatively, the second grooves 7 c and 7 d formed when the heat transfer tube 2 is expanded are formed so that the expanded burette 11 c having the convex portion 12 c having a short length in the length direction of the heat transfer tube 2 is in the length direction of the heat transfer tube 2. It is formed by inserting while rotating.
According to this configuration, the second grooves 7, 7 a, 7 b, 7 c, and 7 d are linear grooves parallel to the length direction of the heat transfer tube 2 or the length of the heat transfer tube 2 using one type of expanded burette 11 c. It can be formed in one of two types of grooves called spiral grooves with respect to the vertical direction. For this reason, it is not necessary to prepare a plurality of types of expanded burettes 11c, which is efficient.

Embodiment 2. FIG.
[Configuration of air conditioner]
FIG. 13 is a schematic configuration diagram showing an air-conditioning apparatus 100 according to Embodiment 2 of the present invention. In FIG. 13, the refrigerant flow during the cooling operation is indicated by a solid arrow, and the refrigerant flow during the heating operation is indicated by a dotted arrow.

As shown in FIG. 13, the air conditioner 100 includes a compressor 101, a four-way valve 102, a heat source side heat exchanger 103 using the heat exchanger 1 of the first embodiment, a throttle device 104, a load side And a heat exchanger 105. The air conditioner 100 includes a heat source side fan 106 that blows air to the heat source side heat exchanger 103 and a load side fan 107 that blows air to the load side heat exchanger 105. The air conditioning apparatus 100 includes pipes 108 and 109 that connect an indoor unit and an outdoor unit. The air conditioner 100 includes control devices 110 and 111 that control various movable parts of the air conditioner 100.
In the air conditioner 100, the compressor 101, the four-way valve 102, the heat source side heat exchanger 103, the expansion device 104, and the load side heat exchanger 105 are connected by a refrigerant pipe to form a refrigerant circulation circuit.

For example, a compressor 101, a four-way valve 102, a throttle device 104, a heat source side fan 106, a load side fan 107, various sensors, and the like are connected to the control devices 110 and 111 via communication lines.
By switching the flow path of the four-way valve 102 by the control devices 110 and 111, the cooling operation and the heating operation are switched. The heat source side heat exchanger 103 acts as a condenser during the cooling operation, and acts as an evaporator during the heating operation. The load side heat exchanger 105 acts as an evaporator during the cooling operation, and acts as a condenser during the heating operation.

[Refrigerant flow during cooling operation]
The high-pressure and high-temperature gas refrigerant discharged from the compressor 101 flows into the heat source side heat exchanger 103 via the four-way valve 102. The refrigerant that has flowed into the heat source side heat exchanger 103 is condensed by heat exchange with the outside air supplied by the heat source side fan 106 to become a high-pressure liquid refrigerant and flows out of the heat source side heat exchanger 103. The high-pressure liquid refrigerant flowing out of the heat source side heat exchanger 103 flows into the expansion device 104 and becomes a low-pressure gas-liquid two-phase refrigerant. The low-pressure gas-liquid two-phase refrigerant flowing out of the expansion device 104 flows into the load-side heat exchanger 105 and evaporates by heat exchange with the indoor air supplied by the load-side fan 107, thereby causing a low-pressure gas state. And flows out of the load-side heat exchanger 105. The low-pressure gaseous refrigerant flowing out from the load-side heat exchanger 105 is sucked into the compressor 101 via the four-way valve 102.

[Refrigerant flow during heating operation]
The high-pressure and high-temperature gas refrigerant discharged from the compressor 101 flows into the load-side heat exchanger 105 through the four-way valve 102. The refrigerant that has flowed into the load-side heat exchanger 105 is condensed by heat exchange with room air supplied by the load-side fan 107, becomes a high-pressure liquid refrigerant, and flows out of the load-side heat exchanger 105. The high-pressure liquid refrigerant flowing out of the load-side heat exchanger 105 flows into the expansion device 104 and becomes a low-pressure gas-liquid two-phase refrigerant. The low-pressure gas-liquid two-phase refrigerant flowing out of the expansion device 104 flows into the heat source side heat exchanger 103 and evaporates by heat exchange with the outside air supplied by the heat source side fan 106, thereby being in a low pressure gas state. It becomes a refrigerant and flows out of the heat source side heat exchanger 103. The low-pressure gaseous refrigerant flowing out of the heat source side heat exchanger 103 is sucked into the compressor 101 via the four-way valve 102.

[Effect of Embodiment 2]
According to the second embodiment, the air conditioner 100 includes the heat exchanger 1 of the first embodiment described above as the heat source side heat exchanger 103.
According to this structure, the air conditioning apparatus 100 can further improve the heat transfer efficiency of the heat transfer tube 2 by including the heat exchanger 1 of the first embodiment.

In the second embodiment, the air conditioner 100 is exemplified as the refrigeration cycle apparatus. However, the present invention is not limited to this. The refrigeration cycle apparatus of the present invention only needs to use the heat exchanger 1 of Embodiment 1 as a condenser or an evaporator. Moreover, you may use the heat exchanger 1 of Embodiment 1 not only for a heat source side heat exchanger but for a load side heat exchanger.

1 heat exchanger, 2 heat transfer tube, 2a heat transfer tube, 2b heat transfer tube, 3 fin, 4 through-hole, 4a fin collar, 5 inner wall, 6 first groove, 7 second groove, 7a second groove, 7b second Groove, 7c 2nd groove, 7d 2nd groove, 8 groove opening width, 9 groove bottom width, 10 groove bottom, 11a tube expansion burette, 11b tube expansion burette, 11c tube expansion burette, 11d tube expansion burette, 12a convex portion, 12b convex portion , 12c convex part, 12d convex part, 13 liquid film, 14 gas, 100 air conditioner, 101 compressor, 102 four-way valve, 103 heat source side heat exchanger, 104 expansion device, 105 load side heat exchanger, 106 heat source side Fan, 107 load side fan, 108 piping, 109 piping, 110 control device, 111 control device.

Claims (23)

1. A heat transfer tube through which the working fluid flows;
   A plurality of fins through which the heat transfer tubes are inserted and arranged in parallel at intervals;
   With
   The heat transfer tube is formed on an inner peripheral wall and has a first groove having a thinner tube thickness than the inner peripheral wall, and is formed in the inner peripheral wall and has a tube thickness thinner than the inner peripheral wall, and the first groove And a second groove having a different shape.
2. The first groove is formed when the heat transfer tube is manufactured,
   The heat exchanger according to claim 1, wherein the second groove is formed when the heat transfer tube inserted through the plurality of fins is expanded.
3. The heat exchanger according to claim 1 or 2, wherein a groove depth of the first groove and a groove depth of the second groove coincide with each other.
4. The heat exchanger according to any one of claims 1 to 3, wherein the second groove is formed to intersect the first groove.
5. The heat exchanger according to any one of claims 1 to 3, wherein the second groove is formed in parallel to the first groove.
6. A plurality of the second grooves are formed,
   The heat exchanger according to any one of claims 1 to 5, wherein the plurality of second grooves have the same shape.
7. A plurality of the second grooves are formed,
   The heat exchanger according to any one of claims 1 to 5, wherein the plurality of second grooves have different shapes.
8. The heat exchanger according to any one of claims 1 to 7, wherein the second groove is formed in a linear shape parallel to a length direction of the heat transfer tube.
9. The heat exchanger according to claim 8, wherein the second groove is formed by straightly inserting a tube expansion burette having a convex portion parallel to the length direction of the heat transfer tube in the length direction of the heat transfer tube.
10. The heat exchanger according to any one of claims 1 to 7, wherein the second groove is formed in a spiral shape with respect to a length direction of the heat transfer tube.
11. The second groove is inserted while rotating a tube expansion burette having a spiral convex portion in the length direction of the heat transfer tube along the spiral convex portion in the length direction of the heat transfer tube. The heat exchanger according to claim 10 formed by:
12. The second groove has an expanded burette having a convex portion whose length is shorter than the width of the cross section perpendicular to the groove length direction of the second groove in the length direction of the heat transfer tube. The heat exchanger according to claim 8 or 10, wherein the heat exchanger is formed by being inserted straight into the heat transfer tube or inserted while being rotated with respect to a length direction of the heat transfer tube.
13. The heat exchanger according to any one of claims 1 to 12, wherein the second groove has a length equal to a groove opening width and a groove bottom width.
14. The heat exchanger according to any one of claims 1 to 12, wherein the second groove has a length different from a groove opening width and a groove bottom width.
15. The heat exchanger according to any one of claims 1 to 12, wherein the second groove has a curved bottom surface.
16. The heat exchanger according to any one of claims 1 to 12, wherein the second groove has a groove bottom portion having no width and a V-shaped cross section perpendicular to the groove length direction.
17. The heat exchanger according to any one of claims 1 to 12, wherein the second groove is formed in a mountain shape parallel to the groove length direction at the groove bottom.
18. The heat exchanger according to any one of claims 1 to 17, wherein the working fluid is an HFO refrigerant, an HFC refrigerant, a natural refrigerant, or a mixed refrigerant thereof.
19. A refrigeration cycle apparatus comprising the heat exchanger according to any one of claims 1 to 18.
20. A heat transfer tube through which the working fluid flows;
    A plurality of fins through which the heat transfer tubes are inserted and arranged in parallel at intervals;
    A method of manufacturing a heat exchanger comprising:
    A first groove is formed in the inner peripheral wall of the heat transfer tube to make the tube thickness thinner than the inner peripheral wall when the heat transfer tube is manufactured;
    The inner wall of the heat transfer tube is made thinner than the inner wall, and a second groove having a shape different from the first groove is formed when the heat transfer tube is inserted through the fins. Heat exchanger manufacturing method.
21. 21. The method of manufacturing a heat exchanger according to claim 20, wherein the second groove is formed by straightly inserting a tube expansion burette having a convex portion parallel to the length direction of the heat transfer tube in the length direction of the heat transfer tube. .
22. The second groove is inserted while rotating a tube expansion burette having a spiral convex portion in the length direction of the heat transfer tube along the spiral convex portion in the length direction of the heat transfer tube. The method for manufacturing a heat exchanger according to claim 20, wherein the method is formed.
23. The second groove has an expanded burette having a convex portion whose length is shorter than the width of the cross section perpendicular to the groove length direction of the second groove in the length direction of the heat transfer tube. 21. The method of manufacturing a heat exchanger according to claim 20, wherein the heat exchanger is formed by being inserted straight into the heat transfer tube or inserted while being rotated with respect to the length direction of the heat transfer tube.

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