JP2020020528A - Heat transfer member, heat transfer tube, heat exchanger, manufacturing method of heat transfer tube and manufacturing method of heat exchanger - Google Patents

Abstract

To provide a heat transfer member which can improve heat transfer performance.SOLUTION: A heat transfer member 1 comprises one group of heat transfer promotion parts 2 including one set of upstream side parts 20, one set of downstream side parts 21 and recesses 22 which are formed at a contact face 11 of fluid. One set of the adjacent upstream side parts 20 protrudes at the contact face 11, is formed into acute angles at the side parts with respect to a main flow direction of fluid, and extends so that the side parts approximate each other as progressing toward an upstream side. One set of the adjacent downstream side parts 21 protrudes at a downstream side rather than the upstream side parts, is formed into acute angles at the side parts with respect to the main flow direction, and extends so that the side parts approximate each other as progressing toward a downstream side. The recesses 22 are recessed rather than the upstream side parts 20 and the downstream side parts 21 at the inside of one set of the upstream side parts 20 and one set of the downstream side parts 21. One group of the heat transfer promotion parts 2 is continuously arranged toward a downstream side in a plurality of groups. The downstream side parts 21 of the upstream-side heat transfer promotion part 2 and the upstream side parts 20 of the downstream-side heat transfer promotion part 2 are integrated to each other.SELECTED DRAWING: Figure 1

Description

  The disclosure in this specification relates to a heat transfer member, a heat transfer tube, a heat exchanger, a method of manufacturing a heat transfer tube, and a method of manufacturing a heat exchanger.

  Patent Literature 1 describes a heat transfer tube in which a concave portion and a protrusion are formed on an inner surface of a tube through which a fluid flows.

Japanese Patent No. 3266886

  According to the heat transfer tube described in Patent Document 1, since the shape of the concave portion in a front view is circular, the downstream end of the concave portion when the fluid flowing along the inner surface of the tube flows out of the concave portion from near the surface of the concave portion The flow which concentrates on is easy to be formed. In this way, the flow in which the fluid gathers from the vicinity of the surface of the concave portion to the downstream end has a problem that the flow resistance when flowing out of the concave portion increases and the heat transfer effect at the peripheral edge portion of the concave portion is concentrated in a narrow range. . There is a need for improvement in the heat transfer between the fluid and a member that contacts the fluid.

  An object of the disclosure in this specification is to provide a heat transfer member, a heat transfer tube and a heat exchanger, a method for manufacturing a heat transfer tube, and a method for manufacturing a heat exchanger, which can improve heat transfer performance.

  The embodiments disclosed in this specification employ different technical means from each other in order to achieve the respective objects. Further, the reference numerals in the parentheses described in the claims and this section are examples showing the correspondence with specific means described in the embodiment described below as one aspect, and limit the technical scope. is not.

One of the disclosed heat transfer members is a contact surface (11) with which the flowing fluid contacts, and sides projecting so as to extend linearly at the contact surface, each of which has an acute angle with respect to the main flow direction of the fluid. A pair of adjacent upstream sides (20) extending closer to the upstream and a side protruding so as to extend linearly downstream of the contact surface with respect to the upstream side. A pair of downstream sides (21) extending so as to approach each other at an acute angle with respect to the direction and proceeding downstream, and a pair of upstream sides and a pair of downstream sides inside. A concave portion (22) provided on the contact surface and being recessed from the upstream side portion and the downstream side portion.
A group of heat transfer enhancing portions (2) including a set of upstream side portions, a set of downstream side portions and a concave portion are provided continuously in a plurality of groups on the contact surface toward the downstream side, and the upstream side and the downstream side are provided. The heat transfer promoting portions adjacent to each other are provided such that the downstream side portion of the upstream heat transfer promoting portion and the upstream side portion of the downstream heat transfer promoting portion are integrated.

  According to this heat transfer member, of the side portions where the concave portion is located on the inner side, a pair of adjacent downstream side portions extending so as to approach each other at an acute angle with respect to the main flow direction of the fluid and proceeding downstream are formed. Have. Due to the shape of the pair of downstream sides, the fluid flowing along the concave portion can flow over the downstream sides while being widely dispersed in the downstream sides. According to the fluid flow that is dispersed and climbs over the downstream side portion, heat transfer in the downstream side portion can be promoted, and the flow of the fluid gathering at the downstream end portion of the concave portion is suppressed. Resistance can be suppressed. Further, of the sides where the concave portion is located on the inner side, there is provided a pair of adjacent upstream sides that extend so as to approach each other at an acute angle with respect to the main flow direction of the fluid and to move further upstream. Due to the shape of the set of upstream sides, the fluid flowing over the set of upstream sides and flowing into the recess can form a flow that collides near the surface of the recess. Contributes to increasing heat transfer.

  Further, the above-mentioned group of heat transfer promoting portions is provided continuously in a plurality of groups on the contact surface toward the downstream, and the downstream side portion of the upstream heat transfer promoting portion and the upstream side portion of the downstream heat transfer promoting portion are provided. And are one. With this configuration, the fluid flows from the vicinity of the surface of the concave portion to the recess side across the vicinity of the surface of the downstream side portion and the upstream side portion, and further flows across the vicinity of the surface of the downstream side portion and the upstream side portion. A flow of flowing into the recess can be continuously formed. Therefore, with the flow of the fluid, the above-described effects can be continuously obtained, and a heat transfer member capable of improving heat transfer performance can be provided.

One of the disclosed heat transfer tubes is a tube inner surface with which a fluid flowing down the inside of the tube (4; 104; 204; 304) comes into contact, and a side portion protruding so as to extend along the tube inner surface. A pair of adjacent upstream sides (20) extend so as to form an acute angle with respect to the direction and advance toward the upstream, and protrude so as to extend along the pipe inner surface downstream of the upstream side. A pair of downstream sides (21), which are adjacent to each other, form an acute angle with respect to the tube axis direction, and extend closer to each other as they progress downstream, and a pair of upstream sides on the inner surface of the tube. A concave portion (22) provided inside the pair of downstream side portions and recessed from the upstream side portion and the downstream side portion;
A group of heat transfer promoting portions (2) including a set of an upstream side portion, a set of a downstream side portion, and a concave portion are provided continuously in a plurality of groups on the inner surface of the tube toward the downstream side, and the upstream side and the downstream side are provided. The heat transfer promoting portions adjacent to each other are provided such that the downstream side portion of the upstream heat transfer promoting portion and the upstream side portion of the downstream heat transfer promoting portion are integrated.

  According to this heat transfer tube, among the side portions where the concave portion is located on the inner side, a pair of adjacent downstream side portions that extend so as to approach each other at an acute angle with respect to the tube axis direction and proceed downstream are provided. I have. Due to the shape of the pair of downstream sides, the fluid flowing along the inner surface of the pipe can be made to flow over the downstream side while being widely dispersed from near the surface of the concave portion to the downstream side. In this way, according to the fluid flow that is dispersed near the inner surface of the pipe and passes over the downstream side portion, heat transfer in the downstream side portion can be promoted, and the flow of the fluid gathering at the downstream end near the surface of the concave portion can be suppressed. Therefore, the flow resistance near the inner surface of the pipe due to the concentration of the fluid can be suppressed. Further, the heat transfer tube has a pair of adjacent upstream sides that extend closer to each other and form an acute angle with respect to the tube axis direction toward the upstream side among the sides where the concave portion is located inside. Due to the shape of the set of upstream sides, the fluid flowing over the set of upstream sides near the inner surface of the pipe and flowing into the recess can form a flow of collision near the surface of the recess. The flow contributes to increasing the heat transfer in the recess.

  Further, a plurality of the above-described group of heat transfer promoting portions are provided continuously in the downstream direction on the inner surface of the pipe, and a downstream side portion of the heat transfer promoting portion on the upstream side and an upstream side portion of the heat transfer promoting portion on the downstream side. And are one. With this configuration, the fluid flows from the vicinity of the surface of the concave portion on the inner surface of the pipe to the concave portion across the vicinity of the surface of the downstream side portion and the upstream side portion, and further flows into the vicinity of the surface of the downstream side portion and the upstream side portion. A flow of traversing into the recess can be continuously formed. Therefore, with the flow of the fluid in the pipe, the above-described operation and effect can be continuously obtained, and a heat transfer pipe with improved heat transfer performance can be provided.

  One of the disclosed heat exchangers includes an inner pipe (4) through which a first fluid flows, and an outer flow path provided between the inner pipe and an outer surface (41) of the inner pipe. An outer tube (3) through which the second fluid flows down, and the inner tube has the above-described configuration of the heat transfer tube. According to this, since the same operation and effect as the above-described heat transfer tube can be obtained in the inner tube, it is possible to provide a heat exchanger capable of improving heat transfer performance.

  One of the disclosed methods of manufacturing a heat transfer tube includes a step of preparing a tube (4; 204), and a first spiral groove (42) and a left-handed winding that proceeds clockwise on the outer surface of the tube in the axial direction of the tube. Forming a second spiral groove (43) that advances to the right, and a first spiral protrusion that advances to the right and a second spiral that advances to the left in the axial direction on the inner surface of the pipe. Forming a protrusion. According to this manufacturing method, it is possible to manufacture a heat transfer tube having the above-described effects, and thus it is possible to provide a heat transfer tube capable of improving heat transfer performance.

  One of the disclosed methods of manufacturing a heat exchanger includes providing an outer tube (3), providing an inner tube (4; 204) having an outer diameter smaller than the inner diameter of the outer tube, and By forming a first spiral groove (42) proceeding clockwise and a second spiral groove (43) proceeding leftward in the axial direction on the outer surface of the tube, the tube is formed on the inner surface of the inner tube. Forming, in the axial direction, a first helical protrusion that progresses clockwise and a second helical protrusion that progresses counterclockwise; and forming a passage between the inner surface of the outer tube and the outer surface of the inner tube. Joining the outer tube and the inner tube to form. According to this manufacturing method, it is possible to manufacture a heat exchanger having the above-described operation and effect, and thus it is possible to provide a heat exchanger capable of improving heat transfer performance.

FIG. 3 is a partial view showing a heat transfer member of the first embodiment. FIG. 2 is a partial cross-sectional view taken along a line II-II in FIG. 1. It is the fragmentary sectional view which showed the upstream side part, the downstream side part, and the recessed part which are facing each other in the heat transfer member. It is the fragmentary sectional view which showed the double tube type heat exchanger provided with the heat exchanger tube of a 2nd embodiment as an inner tube. FIG. 5 is a partial cross-sectional view taken along a line VV in FIG. 4. FIG. 5 is a partial cross-sectional view taken along a line VI-VI in FIG. 4. It is the graph which showed the performance evaluation result of the double tube type heat exchanger concerning a 2nd embodiment. It is a figure for explaining an apparatus which manufactures a heat exchanger tube of a 2nd embodiment. It is the fragmentary sectional view which showed the double tube type heat exchanger provided with the heat exchanger tube of a 3rd embodiment as an inner tube. FIG. 10 is a partial cross-sectional view taken along a line XX in FIG. 9. FIG. 10 is a partial cross-sectional view taken along a line XI-XI in FIG. 9. It is the fragmentary sectional view showing the double tube type heat exchanger provided with the heat exchanger tube of a 4th embodiment as an inner tube. FIG. 13 is a partial cross-sectional view taken along a line XIII-XIII in FIG. 12. FIG. 13 is a partial cross-sectional view taken along a line XIV-XIV in FIG. 12. It is the fragmentary sectional view showing the double tube type heat exchanger provided with the heat exchanger tube of a 5th embodiment as an inner tube. It is the fragmentary sectional view which looked at the XVI-XVI cut surface in FIG. FIG. 16 is a partial cross-sectional view taken along a line XVII-XVII in FIG. 15.

  Hereinafter, a plurality of embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, portions corresponding to the items described in the preceding embodiment are denoted by the same reference numerals, and redundant description may be omitted. When only a part of the configuration is described in each embodiment, the other embodiments described above can be applied to other parts of the configuration. Not only the combination of the parts that clearly indicate that a combination is possible in each embodiment, but also the embodiments can be partially combined without being specified, unless there is any particular problem with the combination. It is also possible.

(1st Embodiment)
The heat transfer member 1 according to the first embodiment will be described with reference to FIGS. The heat transfer member 1 is a member in which heat exchange is performed with a fluid flowing down along the surface, and heat transfer is performed between the fluid and the heat transfer member 1. The heat transfer member 1 is applicable to a member that absorbs heat from a fluid or a member that radiates heat to a fluid. The fluid that flows down around the heat transfer member 1 and comes into contact with the heat transfer member 1 is a heat medium of gas, liquid, or gas-liquid mixture, or may be a fluid that does not undergo a state change or a phase change during use. It may be. The heat transfer member 1 is a member having a plate shape, a block shape, or another shape, and is formed of a material having heat conductivity, for example, a metal.

  As shown in FIG. 1, the heat transfer member 1 has a contact surface 11 with which a flowing fluid contacts. The contact surface 11 includes a flat surface, a curved surface, or a combination thereof. The contact surface 11 is provided with a plurality of groups of heat transfer promoting portions 2 that enhance heat transfer with the fluid. The group of heat transfer promoting portions 2 is formed to include a set of an upstream side 20, a set of a downstream side 21, and a recess 22 provided on the contact surface 11. When the heat transfer member 1 is made of metal, the plurality of groups of heat transfer promoting portions 2a can be formed by, for example, pressing, and when the heat transfer member 1 is made of resin, it can be formed by molding using a mold.

  The pair of upstream side portions 20 are adjacent side portions that protrude so as to extend linearly on the contact surface 11 and are adjacent to each other. The pair of upstream sides 20 extend at an acute angle with respect to the main flow direction of the fluid so as to approach the upstream side. The main flow direction of the fluid is not a partial flow direction of the fluid but a general flow direction of the fluid flowing through the contact surface 11. Adjacent upstream side portions 20 cross each other on the upstream side and are separated farther to the downstream. Adjacent upstream sides 20 intersect at an intersection 23 at the upstream end. The upstream side portion 20 has a protrusion dimension d with respect to the surface of the concave portion 22. It is preferable that the surface of the upstream side portion 20 and the surface of the concave portion 22 are connected by a smooth curve.

  The set of downstream side portions 21 is a side portion protruding so as to extend linearly downstream of the contact surface 11 from the upstream side portion 20. The pair of downstream side portions 21 form acute angles with respect to the main flow direction of the fluid, and extend so as to approach the downstream side. The adjacent downstream side portions 21 intersect on the downstream side and are separated farther to the downstream side. The downstream side portion 21 has a protrusion dimension d with respect to the surface of the concave portion 22. It is preferable that the surface of the downstream side portion 21 and the surface of the concave portion 22 are connected by a smooth curve. Adjacent downstream sides 21 intersect at an intersection 23 at the downstream end. The upstream side portion 20 and the downstream side portion 21 intersect at an intersection 23 which is a downstream end of the upstream side portion 20. It is preferable that the intersection 23 has a distal end surface that forms a curved surface. The intersection 23 has a protruding dimension d with respect to the surface of the recess 22. It is preferable that the surface of the intersection 23 and the surface of the recess 22 are connected by a smooth curve.

  As shown in FIG. 3, the upstream side portion 20 and the downstream side portion 21 preferably have a front end surface that forms a curved surface. This suppresses a vortex generated near the upstream side portion 20 when the fluid flowing down along the contact surface 11 flows over the upstream side portion 20 and flows into the concave portion 22. A vortex generated near the downstream side portion 21 when the vehicle gets over the portion 20 can be suppressed.

  The concave portion 22 is a portion that is recessed from the upstream side portion 20 and the downstream side portion 21 inside the pair of upstream side portions 20 and the pair of downstream side portions 21. The concave portion 22 is a portion surrounded by a pair of upstream side portions 20 and a pair of downstream side portions 21 and is surrounded by four sides. As shown in FIGS. 2 and 3, the surface of the concave portion 22 has a flat surface. It is preferable that the entire surface of the concave portion 22 is a flat surface.

  The shortest distance L2 between the inner wall surface 20w of the upstream side portion 20 and the inner wall surface 21w of the downstream side portion 21 with respect to the upstream side portion 20 and the downstream side portion 21 which are in opposition to each other. The width dimension UR of the surface and the width dimension DR of the cross section of the downstream side portion 21 are sufficiently larger. As shown in FIG. 3, the shortest distance L2 is set to be larger than the total dimension obtained by adding the width dimension UR of the cross section of the upstream side section 20 and the width dimension DR of the cross section of the downstream side section 21. Is preferred.

  It is preferable that the length of the group of heat transfer promoting units 2 along the contact surface 11 in the main flow direction of the fluid is larger than the length along the contact surface 11 in a direction orthogonal to the main flow direction. That is, it is preferable that the group of heat transfer promoting portions 2 have a front view shape that is longer in the mainstream direction than in the orthogonal direction. In this case, the length L1 of the recess 22 along the contact surface 11 in the mainstream direction is larger than the length along the contact surface 11 in the orthogonal direction orthogonal to the mainstream direction.

  In addition, it is preferable that the group of heat transfer promoting portions 2 have a rhombic shape when viewed from the front. In this case, one set of the upstream side part 20 and one set of the downstream side part 21 are side parts that form a rhombus whose four sides are equal in length. The distance L1 between the inner wall surface 23w of the intersection 23 located at the upstream end and the inner wall surface 23w of the intersection located at the downstream end in the mainstream direction in the group of heat transfer promoting units 2 is the width dimension of the cross section of the intersection. It is much larger than R1.

  The plurality of groups of heat transfer promoting sections 2 are provided continuously on the contact surface 11 downstream, for example, as shown in FIG. At least two heat transfer promoting portions 2 are adjacent to each other in an intersecting direction intersecting the main flow direction. In FIG. 1, the main flow direction with respect to the heat transfer promoting unit 2 is illustrated by a white arrow, and the flow crossing the surface of the upstream side 20 and the surface of the downstream side 21 is illustrated by an arrow line.

  FIG. 1 shows heat transfer promotion sections 2a, 2b, 2c, and 2d as an example of a plurality of groups of heat transfer promotion sections 2 provided on the contact surface 11. The heat transfer promoting section 2a is provided adjacent to and upstream of the heat transfer promoting section 2b. The heat transfer promoting section 2a is provided adjacent to and upstream of the heat transfer promoting section 2c. The heat transfer promoting portion 2b and the heat transfer promoting portion 2c are adjacent to each other in a direction perpendicular to the main flow direction downstream of the heat transfer promoting portion 2a. The heat transfer promoting portion 2b and the heat transfer promoting portion 2c are adjacent to each other in an orthogonal direction via an intersection 23 between the side portions. The at least two heat transfer promoting sections 2 are adjacent to each other so as to be continuous in the mainstream direction via an intersection 23 between the sides. The upstream heat transfer promoting section 2a and the downstream heat transfer promoting section 2d are adjacent to each other via the intersection 23 in the main flow direction. The heat transfer promoting portion 2b is provided adjacent to and upstream of the heat transfer promoting portion 2d. The heat transfer promoting section 2c is provided adjacent to and upstream of the heat transfer promoting section 2d.

  The upstream heat transfer promoting section 2a and the downstream heat transfer promoting section 2b are provided adjacent to each other in the cross direction. The downstream side portion 21 in the upstream heat transfer promoting portion 2a and the upstream side portion 20 in the downstream heat transfer promoting portion 2b are integrally formed to form one common side portion. The concave portion 22 of the heat transfer promoting portion 2a and the concave portion 22 of the heat transfer promoting portion 2b are adjacent to each other via an integral downstream side portion 21 and an upstream side portion 20. The upstream heat transfer promoting section 2a and the downstream heat transfer promoting section 2c are provided adjacent to the heat transfer promoting section 2b in the cross direction on the side opposite to the heat transfer promoting section 2b. The downstream side portion 21 in the upstream heat transfer promoting portion 2a and the upstream side portion 20 in the downstream heat transfer promoting portion 2c are integrally formed to form one common side portion. The concave portion 22 of the heat transfer promoting portion 2a and the concave portion 22 of the heat transfer promoting portion 2c are adjacent to each other via an integral downstream side portion 21 and an upstream side portion 20.

  With such a configuration, in the vicinity of the surface of the concave portion 22 in the heat transfer promoting portion 2a, the fluid flowing down along the contact surface 11 has a set of the upstream side portions 20 from the heat transfer promoting portion 2 located upstream. They come across each other and come into collision. The fluid that has flowed into the vicinity of the surface of the concave portion 22 is divided into two in the cross direction so as to cross each of the pair of downstream side portions 21, one of which flows into the concave portion 22 of the heat transfer promoting portion 2 b and the other flows into the concave portion 22. The fluid flows into the concave portion 22 of the transmission promoting portion 2c.

  The upstream heat transfer promoting section 2b and the downstream heat transfer promoting section 2d are provided adjacent to each other in the cross direction. The downstream side portion 21 of the upstream heat transfer promoting portion 2b and the upstream side portion 20 of the downstream heat transfer promoting portion 2d are integrally formed to form one common side portion. The concave portion 22 of the heat transfer promoting portion 2b and the concave portion 22 of the heat transfer promoting portion 2d are adjacent to each other via a downstream side portion 21 and an upstream side portion 20 which are integrated. The upstream heat transfer promoting section 2c and the downstream heat transfer promoting section 2d are provided adjacent to the heat transfer promoting section 2b in the cross direction on the side opposite to the heat transfer promoting section 2b. The downstream side portion 21 of the upstream heat transfer promoting portion 2c and the upstream side portion 20 of the downstream heat transfer promoting portion 2d are integrally formed to form one common side portion. The concave portion 22 of the heat transfer promoting portion 2c and the concave portion 22 of the heat transfer promoting portion 2d are adjacent to each other via an integral downstream side portion 21 and an upstream side portion 20.

  With such a configuration, in the vicinity of the surface of the concave portion 22 of the heat transfer promoting portion 2b, a fluid is formed in a pair with the heat transfer promoting portion 2 adjacent to the heat transfer promoting portion 2a in a direction orthogonal to the heat transfer promoting portion 2a. The water flows across each of the upstream side portions 20 and comes into collision with each other. The fluid that has flowed into the vicinity of the surface of the concave portion 22 is divided into two in the cross direction so as to cross each of the pair of downstream side portions 21, and one of the two flows into the concave portion 22 of the heat transfer promoting portion 2 adjacent in the cross direction. The other flows into the concave portion 22 of the heat transfer promoting portion 2d.

  In the vicinity of the surface of the concave portion 22 of the heat transfer promoting portion 2c, a fluid is provided in a set of upstream side portions from the heat transfer promoting portion 2 adjacent to the heat transfer promoting portion 2a in a direction orthogonal to the heat transfer promoting portion 2a. 20 will flow across each other and come into collision. The fluid that has flowed into the vicinity of the surface of the concave portion 22 is divided into two in the cross direction so as to cross each of the pair of downstream side portions 21, one of which flows into the concave portion 22 of the heat transfer promoting portion 2 d and the other crosses. It flows into the concave portion 22 of the heat transfer promoting portion 2 adjacent in the direction. Further, the fluid that has flowed into the concave portion 22 of the heat transfer promoting portion 2d from the heat transfer promoting portion 2b and the heat transfer promoting portion 2c across each of the pair of upstream side portions 20 collides near the surface of the concave portion 22. It will fit. The fluid that has flowed into the vicinity of the surface of the concave portion 22 is divided into two in the cross direction so as to cross each of the pair of downstream side portions 21, and two heat transfer enhancements adjacent to each other in the orthogonal direction via the cross portion 23. It flows into the section 2.

  The operation and effect provided by the heat transfer member 1 of the first embodiment will be described. The heat transfer member 1 is a group of heat transfer including a contact surface 11 with which the flowing fluid contacts, a set of an upstream side 20, a set of a downstream side 21, and a recess 22 provided on the contact surface 11. And a promoting unit 2. A pair of adjacent upstream side portions 20 are side portions protruding so as to extend linearly on the contact surface 11, and extend so as to form an acute angle with respect to the main flow direction of the fluid and to approach the upstream side. I have. A pair of adjacent downstream sides 21 are sides that protrude so as to extend linearly downstream of the contact surface from the upstream side, and form an acute angle with respect to the main flow direction, and become closer to the downstream. So that it extends. The concave portion 22 is a portion that is recessed from the upstream side portion 20 and the downstream side portion 21 inside the pair of upstream side portions 20 and the pair of downstream side portions 21. A plurality of groups of heat transfer promoting portions 2 are provided continuously on the contact surface 11 toward the downstream side. In the heat transfer promoting portion 2 adjacent on the upstream side and the downstream side, the downstream side portion 21 of the heat transfer promoting portion 2 on the upstream side and the upstream side portion 20 of the heat transfer promoting portion 2 on the downstream side are integrated. It is provided.

  According to the heat transfer member 1, the shape of the pair of downstream sides 21 in the mainstream direction allows the fluid flowing along the contact surface 11 to be widely dispersed from near the surface of the concave portion 22 to the downstream sides 21. It can flow out over each downstream side portion 21. Further, the fluid flowing out of the concave portion 22 across the surface of each downstream side portion 21 also flows over the surface of the upstream side portion 20 that is united with the downstream side portion 21 and flows into the internal concave portion 22. Can be repeated near the contact surface 11. As described above, according to the fluid flow passing over the downstream side portion 21 while being dispersed in the vicinity of the contact surface 11, heat transfer of the downstream side portion 21 over a wide range can be promoted. Further, since the flow of the fluid that collects at the downstream end near the surface of the concave portion 22 can be suppressed, the flow resistance in the vicinity of the contact surface 11 due to the concentration of the fluid can be suppressed, which can contribute to the improvement of heat transfer.

  Further, the heat transfer member 1 is configured such that the fluid flowing along the contact surface 11 passes over each of the pair of upstream side portions 20 and then the concave portion 22 has A flow can be formed that collide near the surface. The flow that intersects so as to intersect near the surface of the concave portion 22 contributes to increasing the heat transfer between the fluid flowing down the contact surface 11 and the concave portion 22. The heat transfer member 1 includes a plurality of groups of heat transfer promoting sections 2 provided in a continuous manner. The downstream side section 21 of the upstream heat transfer promoting section 2 and the upstream side section 20 of the downstream heat transfer promoting section 2 are connected to each other. With the single structure, a fluid flow that moves the contact surface 11 in the order of the concave portion 22, the side portion, the concave portion 22, and the side portion can be formed. Therefore, since the heat transfer member 1 can continuously obtain the above-described operation and effect as the fluid flows down, the heat transfer performance can be improved.

  Since the heat transfer member 1 contributes to suppressing the flow resistance in the fluid flow along the contact surface 11 and improving the heat transfer, the heat transfer member 1 is more remarkable in a device in which a gas or a gas-liquid two-layer fluid having a lower viscosity than a liquid flows down. It is effective.

  A group of heat transfer promoting sections 2 are provided adjacent to each other in the contact surface 11 in both the cross direction and the main flow direction crossing the main flow direction of the fluid. According to this configuration, a fluid flow moving in the order of the concave portion 22, the side portion, the concave portion 22, and the side portion in the cross direction and a fluid flow moving in a zigzag manner in the main flow direction can be formed. Therefore, the heat transfer member 1 can continuously obtain the above-described effects over a wide range of the contact surface 11.

  The group of heat transfer promoting sections 2 has a length dimension along the contact surface 11 in the main flow direction of the fluid larger than a length dimension along the contact surface 11 in a direction orthogonal to the main flow direction. According to this configuration, the concave portion 22 can have a shape that is longer along the contact surface 11 in the mainstream direction than in the orthogonal direction along the contact surface 11. As a result, after the fluid flowing along the contact surface 11 gets over each of the pair of upstream side portions 20, the area where the fluid collides near the surface of the concave portion 22 can be lengthened in the main flow direction. The heat transfer between the fluid flowing down and the recess 22 can be improved.

  The recess 22 is a portion surrounded by a set of the upstream side 20 and a set of the downstream side 21. According to this configuration, the heat transfer member 1 includes a plurality of groups of the heat transfer promoting portions 2 each including the concave portions 22 surrounded by the sides protruding in a lattice shape on the contact surface 11. Therefore, by forming the side portions protruding in a lattice shape on the contact surface 11, the heat transfer member 1 having the above-described operational effects can be obtained.

  One set of upstream side parts 20 and one set of downstream side parts 21 are sides forming a rhombus shape. According to this configuration, by forming the side portions protruding in a lattice shape on the contact surface 11 such that the side length of the upstream side portion 20 and the side length of the downstream side portion 21 are equal or almost equal, It is possible to obtain the heat transfer member 1 having the above-described effects. In addition, since the heat transfer promoting portion 2 has such a shape, the heat transfer member 1 with a good balance between the suppression of the flow resistance described above and the improvement of the heat transfer described above can be provided.

  The surface of the recess 22 has a flat surface. According to this configuration, the range in which the fluid that has passed over each of the pair of upstream side portions 20 is mixed near the surface of the concave portion 22 to form a turbulent flow is formed so as not to largely vary with respect to the contact surface 11. can do. Thereby, the effect of improving the heat transfer in the concave portion 22 can be made closer to a uniform state.

  The shortest distance L2 between the inside wall surface 20w of the upstream side portion 20 and the inside wall surface 21w of the downstream side portion 21 of the upstream side portion 20 and the downstream side portion 21 in the opposing relationship is the cross section of the upstream side portion 20. Is larger than the sum of the width dimension UR and the width dimension DR of the cross section of the downstream side 21. Since the concave portion 22 is set to such a size, a turbulent flow can be formed near the surface of the concave portion 22 such that the fluid flowing over the pair of upstream side portions 20 and flowing into the concave portion 22 collides with each other. The heat transfer in the recess 22 can be promoted.

  The upstream side portion 20 and the downstream side portion 21 of the heat transfer member 1 have a distal end surface that forms a curved surface. According to this configuration, when the fluid flowing down along the contact surface 11 flows down from near the surface of the concave portion 22 over the downstream side portion 21 integrated with the upstream side portion 20, the downstream side portion 21 The vortex generated in the vicinity can be suppressed, which contributes to the formation of a smooth fluid flow.

(2nd Embodiment)
A second embodiment will be described with reference to FIGS. The second embodiment discloses a heat transfer tube provided with a plurality of groups of heat transfer promoting units 2 of the first embodiment. Further, the second embodiment discloses a mode in which this heat transfer tube is used as an inner tube 4 provided in a double-tube heat exchanger. In each of the drawings, components having the same configuration as the first embodiment are denoted by the same reference numerals, and have similar functions and effects. Configurations, operations, and effects that are not particularly described in the second embodiment are the same as those in the first embodiment, and differences from the first embodiment will be described below. Regarding the heat transfer tubes provided with the plurality of groups of heat transfer promoting portions 2, the tube axis direction which is the direction along the tube axis 40 which is the center axis of the tube corresponds to the main flow direction of the fluid in the first embodiment.

  As shown in FIGS. 4 to 6, the inner tube 4 as an example of the heat transfer tube has a plurality of groups of heat transfer promoting portions 2 provided on the inner surface of the tube with which the fluid comes into contact. The set of upstream side parts 20 and the set of downstream side parts 21 are side parts protruding so as to extend along the inner surface of the pipe. The concave portion 22 is provided inside the pair of upstream side portions 20 and the pair of downstream side portions 21 on the pipe inner surface, and is located between the upstream side portion 20 and the downstream side portion 21 with respect to the pipe inner surface. It is concave. Therefore, the heat transfer tube is a tube in which the contact surface 11 is rounded into a cylindrical shape so that the contact surface 11 of the first embodiment forms an inner surface of the tube.

  The double-pipe heat exchanger shown in FIG. 4 includes an inner pipe 4 in which the first fluid flows down and an outer flow path provided between the inner pipe 4 and the outer surface 41 of the inner pipe 4. An outer pipe 3 through which the second fluid flows down, and an inflow pipe 31 through which the second fluid flows into the outer flow path are provided. The first fluid and the second fluid exchange heat via the inner pipe 4. In the second embodiment, a low-pressure refrigerant is used as the first fluid, and a high-pressure refrigerant is used as the second fluid. Further, the heat exchanger preferably includes a group of heat transfer promoting portions 2 provided over the entire portion of the inner tube 4 where the first fluid and the second fluid exchange heat.

  In the refrigeration cycle, this heat exchanger is a double-pipe internal heat exchanger that uses the high-temperature high-pressure refrigerant flowing out of the condenser as the second fluid and the low-temperature low-pressure refrigerant flowing out of the evaporator as the first fluid. Can be applied. The double-pipe internal heat exchanger can exchange heat with high efficiency by providing the inner pipe 4 having the plurality of groups of heat transfer promoting sections 2, so that the internal heat exchanger having no heat transfer promoting section can be used. On the other hand, the cooling performance can be improved and the coefficient of performance of the refrigeration cycle can be improved.

  The inner tube 4 includes an outer groove 42 and an outer groove 43 formed on the outer surface. The outer surface side groove portion 42 is a groove portion formed on the outer surface 41 in a spiral shape clockwise with respect to the tube shaft 40. The outer surface side groove portion 43 is a groove portion formed on the outer surface 41 in a helical shape wound leftward with respect to the tube shaft 40. The outer surface side groove portion 42 and the outer surface side groove portion 43 are formed so as to intersect on the outer surface 41. An upstream side portion 20 and a downstream side portion 21 are formed on the back side of the outer surface side groove portion 42 and the outer surface side groove portion 43. The intersection 23 is formed on the back side of the intersection of the outer surface groove 42 and the outer surface groove 43. A concave portion 22 is formed on the back side of a portion of the outer surface 41 surrounded by the outer surface side groove portion 42 and the outer surface side groove portion 43.

  FIG. 7 is a graph showing performance evaluation results of the double-tube internal heat exchanger of the second embodiment. The horizontal axis represents the pressure loss ratio of the inner pipe with the smooth pipe inner surface to the pipe passage. The evaluation results shown on the vertical axis are the heat exchange ratios when the heat exchange amount in the internal heat exchanger having the inner tube whose inner surface is smooth is set to 1. The dimension d is a protrusion dimension of the upstream side portion 20 with respect to the surface of the flat concave portion 22, and is a protrusion size of the downstream side portion 21 with respect to the surface of the flat concave portion 22. The dimension D is an outer diameter dimension of the inner tube 4. The internal heat exchanger with the inner tube 4 set to d / D = 0.07 to 0.1 has higher heat than the internal heat exchanger with the inner tube having only one spiral groove on the inner surface of the tube. It has been confirmed that the exchange ratio can be obtained. The internal heat exchanger with the inner tube 4 set at d / D = 0.05 has higher heat than the internal heat exchanger with the inner tube 4 set at d / D = 0.07-0.1. It has been confirmed that the exchange ratio can be obtained.

  The method for manufacturing the inner tube 4 which is a heat transfer tube includes a step of preparing the inner tube 4, a right-handed first helical protrusion and a left-handed second helical protrusion on the inner surface of the inner tube 4. And a forming step of forming In the forming step, a first helical groove progressing clockwise in the pipe axis direction and a second helical groove progressing clockwise in the pipe axis direction are formed on the outer surface of the inner pipe 4, so that the clockwise winding is performed in the pipe axis direction. And a second spiral projection that progresses counterclockwise. The first helical groove corresponds to the outer groove 42, and the second helical groove corresponds to the outer groove 43. The first helical protrusion and the second helical protrusion correspond to one set of the upstream side part 20 and one set of the downstream side part 21.

  FIG. 8 shows an apparatus for manufacturing the inner tube 4 which is a heat transfer tube. As shown in FIG. 8, the processing device 5 advances the inner pipe 4 clockwise in a state where the groove processing portion 51 provided at the tip of the press tool 50 is pressed against the outer surface of the pipe and the inner pipe 4 is plastically deformed. By doing so, the first spiral groove can be formed. The processing device 5 forms the first spiral groove on the outer surface of the tube and simultaneously forms the first spiral protrusion on the inner surface of the tube. Further, the processing device 5 can form the second spiral groove by moving the inner pipe 4 left-handed in a state where the groove processing part 51 is pressed against the outer surface of the pipe and the inner pipe 4 is plastically deformed. The processing device 5 forms the second spiral groove on the outer surface of the tube and simultaneously forms the second spiral protrusion on the inner surface of the tube. Then, the heat exchanger shown in FIG. 4 performs a joining step of joining the outer tube 3 and the inner tube 4 so as to form a passage between the inner tube 4 thus formed and the inner surface of the outer tube 3. Can be manufactured by

  The operation and effect provided by the heat transfer tube of the second embodiment will be described. The heat transfer tube having the inner tube 4 as an example includes a tube inner surface with which a fluid flowing down the inside of the tube comes into contact, a set of upstream side portions 20, a set of downstream side portions 21, and a concave portion provided on the tube inner surface. And a group of heat transfer promoting portions 2 including the first heat transfer portion 22. A pair of adjacent upstream side portions 20 are side portions protruding so as to extend along the inner surface of the pipe, and form acute angles with respect to the pipe axis direction and extend closer to the upstream side. A pair of adjacent downstream side portions 21 are side portions protruding so as to extend along the pipe inner surface downstream of the upstream side portion 20. It extends to approach. The concave portion 22 is provided inside the pair of upstream side portions 20 and the pair of downstream side portions 21 on the inner surface of the pipe, and is recessed from the upstream side portion 20 and the downstream side portion 21. The group of heat transfer promoting sections 2 is provided continuously in plural groups toward the downstream side on the inner surface of the tube. In the heat transfer promoting portion 2 adjacent on the upstream side and the downstream side, the downstream side portion 21 of the heat transfer promoting portion 2 on the upstream side and the upstream side portion 20 of the heat transfer promoting portion 2 on the downstream side are integrated. It is provided as follows.

  According to this heat transfer tube, the fluid flowing along the inner surface of the pipe is widely dispersed from the vicinity of the surface of the concave portion 22 to the downstream side portion 21 by the shape of the pair of downstream side portions 21 in the tube axis direction. It can flow out over the downstream side portion 21. Further, the fluid that has flowed out of the concave portion 22 across the surface of each downstream side portion 21 also gets over the surface of the upstream side portion 20 that is united with the downstream side portion 21 and flows into the internal concave portion 22. This flow can be continuously repeated near the inner surface of the pipe.

  As described above, according to the fluid flow passing over the downstream side portion 21 while being dispersed near the inner surface of the pipe, heat transfer over a wide range of the downstream side portion 21 can be promoted. Furthermore, since the flow of the fluid that collects at the downstream end near the surface of the concave portion 22 can be suppressed, the flow resistance near the inner surface of the pipe due to the concentration of the fluid can be suppressed, and the heat transfer can also be improved.

  The heat transfer tube contributes to the suppression of flow resistance and the improvement of heat transfer in the fluid flow along the inner surface of the tube, so it exerts a more remarkable effect in devices in which gas or gas-liquid two-layer fluid with lower viscosity than liquid flows down I do.

  Further, the heat transfer tube has a shape in the tube axis direction provided by the set of upstream sides 20, so that the fluid flowing along the inner surface passes over each of the set of upstream sides 20, and then near the surface of the recess 22. A collision flow can be formed. The flow mixed so as to intersect near the surface of the concave portion 22 contributes to enhancing the heat transfer between the fluid flowing down the inner surface of the pipe and the concave portion 22.

  In the heat transfer promotion unit 2 provided in a plurality of groups, the heat transfer tube includes one downstream side 21 of the heat transfer promotion unit 2 on the upstream side and one upstream side 20 of the heat transfer promotion unit 2 on the downstream side. With this configuration, a fluid flow that moves in the order of the concave portion 22, the side portion, the concave portion 22, and the side portion along the inner surface of the pipe can be formed. Therefore, the heat transfer tube can continuously obtain the above-described operation and effect as the fluid flows down in the tube, so that the heat transfer performance can be improved.

  A plurality of heat transfer promoting portions 2 provided in the heat transfer tube are provided adjacent to each other in both the cross direction and the tube axis direction crossing the tube axis direction on the inner surface of the tube. According to this configuration, along the inner surface of the pipe, a fluid flow that moves in the order of the concave portion 22, the side portion, the concave portion 22, and the side portion in the cross direction and a fluid flow that moves in a zigzag manner in the main flow direction are formed. be able to. Therefore, the heat transfer tube can continuously obtain the above-described effects over a wide range of the inner surface of the tube.

  It is preferable that the group of heat transfer promoting portions 2 provided in the heat transfer tube have a length in the tube axis direction larger than a length in the circumferential direction. According to this configuration, it is possible to form the concave portion 22 having a shape in which the length along the pipe inner surface in the pipe axis direction is longer than the length along the pipe inner surface in the circumferential direction. Thereby, after the fluid flowing along the inner surface of the pipe passes over each of the pair of upstream side portions 20, the area where the fluid collides near the surface of the concave portion 22 can be lengthened in the pipe axis direction. The heat transfer between the fluid flowing down the inner surface of the pipe and the recess 22 can be improved.

  The concave portion 22 provided in the heat transfer tube is a portion surrounded by one set of the upstream side part 20 and one set of the downstream side part 21. According to this configuration, the heat transfer tube includes a plurality of groups of the heat transfer promoting portions 2 each including the concave portion 22 surrounded by the side protruding in a lattice shape on the inner surface of the tube. Therefore, by forming the side portions protruding in a lattice shape on the inner surface of the tube, it is possible to obtain a heat transfer tube having the above-described effects.

  The pair of upstream sides 20 and the pair of downstream sides 21 provided in the heat transfer tube are preferably sides that exhibit a rhombic shape when the inner surface of the tube is developed in a plane. According to this configuration, by forming the side portions projecting in a lattice shape on the inner surface of the tube such that the side length of the upstream side portion 20 and the side length of the downstream side portion 21 are equal or almost equal, the above-described configuration is achieved. Thus, it is possible to obtain a heat transfer tube having the function and effect of (1). In addition, since the heat transfer promoting section 2 has such a shape, a heat transfer tube with a good balance between the suppression of the flow resistance described above and the improvement of the heat transfer described above can be provided.

  As for the inner surface of the heat transfer tube, the creepage distance along the inner surface of the inner wall surface 20w of the upstream side portion 20 and the inner wall surface 21w of the downstream side portion 21 is upstream with respect to the upstream side portion 20 and the downstream side portion 21 facing each other. It is larger than the sum of the width dimension UR of the cross section of the side section 20 and the width dimension DR of the cross section of the downstream side section 21. Since the concave portion 22 is set to such a size on the inner surface of the pipe, a turbulent flow in which the fluid flowing over the pair of upstream side portions 20 and flowing into the concave portion 22 collides near the surface of the concave portion 22 is formed. Since it can be formed, heat transfer in the concave portion 22 can be promoted.

  The upstream side portion 20 and the downstream side portion 21 of the heat transfer tube have a distal end surface that forms a curved surface. According to this configuration, when the fluid flowing down along the inner surface of the pipe flows down from near the surface of the concave portion 22 over the downstream side portion 21 integrated with the upstream side portion 20, the vicinity of the downstream side portion 21. The vortex generated in the fluid can be suppressed, which contributes to the formation of a smooth fluid flow.

  The heat transfer tube includes an outer groove 42 and an outer groove 43 formed on the outer surface of the tube. The upstream side portion 20 and the downstream side portion 21 are provided on the back side of the outer surface side groove portion 42 and the outer surface side groove portion 43. According to this configuration, a plurality of groups of the heat transfer promoting portions 2 including the upstream side portion 20 and the downstream side portion 21 provided on the back side of the outer surface side groove portion 42 and the outer surface side groove portion 43 are provided. Therefore, by forming the outer surface side groove portion 42 and the outer surface side groove portion 43 that form the upstream side portion 20 and the downstream side portion 21 on the tube inner surface side on the outer surface of the tube, a heat transfer tube having the above-described operational effects is obtained. be able to.

  The longitudinal cross-sectional shape of the concave portion 22 provided in the heat transfer tube forms a flat surface. It is preferable that each protrusion dimension d of the upstream side portion 20 and the downstream side portion 21 with respect to the flat surface is set to be 0.1 times or less the outer diameter dimension D of the pipe. According to this configuration, as described above with reference to FIG. 7, the conventional heat transfer tube in which the side and the recess are not formed in the tube inner surface or the conventional transfer tube in which only the spiral groove is formed in the tube inner surface. It is possible to provide a heat transfer tube capable of greatly improving heat transfer performance as compared with a heat tube.

  In the double-pipe heat exchanger, the second fluid is supplied to the outer flow path provided between the inner pipe 4 in which the first fluid flows down and the outer surface 41 of the inner pipe 4 that houses the inner pipe 4. And an outer pipe 3 flowing down. The inner tube 4 has the configuration of the heat transfer tube described above. According to this configuration, the same effect as the above-described heat transfer tube can be obtained in the inner tube 4, so that a heat exchanger with improved heat transfer performance can be provided.

  Further, a plurality of groups of heat transfer promoting portions 2 provided in the heat exchanger are provided over the entire portion of the inner pipe 4 where the first fluid and the second fluid exchange heat. According to this configuration, it is possible to provide a double-pipe heat exchanger capable of improving the heat transfer performance over the entire portion where the first fluid and the second fluid exchange heat.

  The method of manufacturing a heat transfer tube includes the steps of preparing a tube and forming, on the outer surface of the tube, a first spiral groove progressing clockwise and a second spiral groove progressing left in the axial direction of the tube. Forming a first helical projection that progresses clockwise and a second helical projection that progresses leftward in the pipe axis direction on the inner surface of the pipe. According to this manufacturing method, by forming right-handed and left-handed spiral grooves on the outer surface of the tube, a plurality of groups of heat transfer promoting portions 2 including the side portions projecting like a lattice and the concave portions 22 on the inner surface of the tube. Can be formed. Therefore, according to this manufacturing method, it is possible to manufacture a heat transfer tube having the above-described operation and effect, and it is possible to provide a heat transfer tube capable of improving heat transfer performance.

  The method for manufacturing the heat exchanger includes a step of preparing the outer pipe 3 and a step of preparing the inner pipe 4 having an outer diameter smaller than the inner diameter of the outer pipe 3. Further, this manufacturing method includes a forming step of forming a spiral groove on the inner surface of the inner tube 4 and a joining step. In the forming step, a first helical groove progressing clockwise in the pipe axis direction and a second helical groove progressing clockwise in the pipe axis direction are formed on the outer surface of the inner pipe 4 so that the pipe shaft is formed on the inner surface of the inner pipe 4. A first helical protrusion that progresses clockwise in the direction and a second helical protrusion that progresses counterclockwise in the direction are formed. In the joining step, the outer tube 3 and the inner tube 4 are joined so as to form a passage between the inner surface of the outer tube 3 and the outer surface of the inner tube 4.

  According to this manufacturing method, by forming the right-handed and left-handed spiral grooves on the outer surface of the inner tube 4, a plurality of groups of heat including the side portions and the recesses 22 projecting in a grid on the inner surface of the inner tube 4 are formed. The transmission promotion part 2 can be formed. Therefore, according to this manufacturing method, since the inner tube 4 can be manufactured as a heat transfer tube having the above-described effects, a double-pipe heat exchanger that can improve heat transfer performance can be provided.

(Third embodiment)
A third embodiment will be described with reference to FIGS. The third embodiment discloses a heat transfer tube provided with a plurality of groups of heat transfer promoting sections 2 as in the second embodiment, and is different from the double tube heat exchanger of the second embodiment. The shape of the outer surface side groove 143 formed on the outer surface 41 of the inner tube 104 is different. In each of the drawings, components having the same configuration as those of the first embodiment and the second embodiment are denoted by the same reference numerals, and have similar functions and effects. Configurations, operations, and effects that are not particularly described in the third embodiment are the same as those in the above-described embodiment, and different points will be described below.

  As shown in FIGS. 9 to 11, the inner tube 104 includes an outer groove 42 and an outer groove 143 formed on the outer surface 41. The outer surface side groove portion 143 is a groove portion formed in a left-handed spiral shape in which a groove portion is not formed partially with respect to the outer surface side groove portion 43. The outer surface side groove portion 42 and the outer surface side groove portion 143 have an angle so as to intersect with each other on the outer surface 41. An upstream side portion 20 and a downstream side portion 21 are formed on the back side of the outer surface side groove portion 42. An upstream side portion 120 and a downstream side portion 121 are formed on the back side of the outer surface side groove portion 42. The upstream side portion 120 and the downstream side portion 121 have the same functions and effects as the upstream side portion 20 and the downstream side portion 21. An intersection 23 is formed on the back side of the intersection of the outer surface groove 42 and the outer surface groove 143. On the outer surface 41, a concave portion 22 is formed on the back side of an inner portion between the outer surface side groove portion 42 and the outer surface side groove portion 143. The first spiral groove corresponds to the outer groove 42, and the second spiral groove corresponds to the outer groove 143.

  According to the third embodiment, the heat transfer tube includes the outer surface side groove portion 42 and the outer surface side groove portion 143 formed on the outer surface of the tube. The upstream side portions 20 and 120 and the downstream side portions 21 and 121 are provided on the back side of the outer surface side groove portion 42 and the outer surface side groove portion 143. According to this configuration, there are provided a plurality of groups of heat transfer promoting portions 2 including the upstream side portions 20 and 120 and the downstream side portions 21 and 121 provided on the back side of the outer surface side groove portion 42 and the outer surface side groove portion 143, respectively. Therefore, by forming the outer surface side groove portion 42 and the outer surface side groove portion 143 which form the upstream side portions 20 and 120 and the downstream side portions 21 and 121 on the tube inner surface side on the outer surface of the tube, the above-described operation and effect can be obtained. Heat transfer tubes can be obtained.

(Fourth embodiment)
A fourth embodiment will be described with reference to FIGS. The fourth embodiment discloses a heat transfer tube provided with a plurality of groups of heat transfer promoting portions 2 as in the second embodiment, and is different from the double tube heat exchanger of the second embodiment. The pitch of the outer surface side groove 43 formed on the outer surface 41 is set small. In each figure, components having the same configuration as the first embodiment and the second embodiment are denoted by the same reference numerals and have the same functions and effects. Configurations, operations, and effects that are not particularly described in the fourth embodiment are the same as those in the above-described embodiment.

  As shown in FIG. 12 to FIG. 14, a pair of upstream side portions 20 and a pair of downstream side portions 21 provided on the inner surface of the inner tube 204 are formed when the inner surface of the tube is developed into a plane. It is a side that exhibits a parallelogram.

(Fifth embodiment)
A fifth embodiment will be described with reference to FIGS. The fifth embodiment discloses a heat transfer tube provided with a plurality of groups of heat transfer promoting sections 2 as in the second embodiment, and is different from the double-tube heat exchanger of the second embodiment. , In that no groove is formed on the outer surface 41 of the inner tube 304. In each of the drawings, components having the same configuration as that of the above-described embodiment are denoted by the same reference numerals, and have similar functions and effects. Configurations, operations, and effects that are not particularly described in the fifth embodiment are the same as those in the above-described embodiment, and different points will be described below.

  As shown in FIG. 15 to FIG. 17, the inner tube 304 has a set of upstream sides forming a group of heat transfer promoting portions 2 on the inner surface of the tube even though the outer surface side groove portion is not formed on the outer surface 41. A portion 20 and a pair of downstream side portions 21 are provided.

(Other embodiments)
The disclosure of this specification is not limited to the illustrated embodiments. The disclosure includes the illustrated embodiments and variations based thereon based on those skilled in the art. For example, the disclosure is not limited to the combination of the components and elements shown in the embodiment, and can be implemented with various modifications. The disclosure can be implemented in various combinations. The disclosure may have additional parts that can be added to the embodiments. The disclosure includes those in which the components and elements of the embodiments are omitted. The disclosure encompasses the replacement or combination of parts, elements, between one embodiment and another. The disclosed technical scope is not limited to the description of the embodiments. The disclosed technical range is shown by the description of the claims, and should be construed to include all modifications within the meaning and scope equivalent to the description of the claims.

  The group of heat transfer promoting portions that can achieve the object disclosed in the specification is not limited to the front view shape disclosed in the above embodiment. A group of heat transfer promoting parts are rhombic, square, and the lengths of adjacent upstream sides are substantially equal, and the lengths of adjacent downstream sides are substantially equal. Alternatively, a front-view shape such as a kite-shaped square having two sets of sides having the same length may be configured.

2 ... heat transfer promoting section, 4,104,204,304 ... inner pipe (pipe, heat transfer pipe)
Reference Signs List 11 contact surface 20 upstream side 20 w inner wall 21 downstream side 21 w inner wall 22 concave portion 41 outer surface 42 outer surface groove (first spiral groove) 43 … Outer surface side groove (second spiral groove)
143: outer surface side groove portion (second spiral groove portion)

Claims (21)

A contact surface (11) with which the flowing fluid contacts,
A pair of adjacent upstream sides (20), which are protruded so as to extend in a straight line on the contact surface, and extend so as to form an acute angle with respect to the main flow direction of the fluid and become closer to the upstream as the fluid advances. )When,
A pair of sides that protrude so as to extend linearly downstream of the contact surface from the upstream side side, and extend so as to approach each other at an acute angle with respect to the main flow direction and progress toward the downstream, and a pair of adjacent ones A downstream side (21) of
A recess (22) provided on the contact surface inside the pair of the upstream side and the pair of the downstream side, and recessed from the upstream side and the downstream side;
With
A group of heat transfer promoting portions (2) including a set of the upstream side portion, a set of the downstream side portion, and the concave portion are provided continuously in a plurality of groups downstream on the contact surface,
The heat transfer promoting portion adjacent on the upstream side and the downstream side is formed by integrating the downstream side portion of the heat transfer promoting portion on the upstream side and the upstream side portion of the heat transfer promoting portion on the downstream side. Heat transfer member is provided.   2. The heat transfer member according to claim 1, wherein a plurality of the groups of heat transfer promoting portions are provided adjacent to each other in both the cross direction intersecting with the main flow direction and the main flow direction on the contact surface.   The group of heat transfer enhancing portions, wherein a length dimension along the contact surface in the mainstream direction is larger than a length dimension along the contact surface in a direction orthogonal to the mainstream direction. The heat transfer member according to claim 2.   4. The heat transfer member according to claim 1, wherein the recess is a portion surrounded by a pair of the upstream side and a pair of the downstream side. 5.   The heat transfer member according to claim 4, wherein the pair of upstream sides and the pair of downstream sides are sides forming a rhombus.   The heat transfer member according to any one of claims 1 to 5, wherein a surface of the recess has a flat surface.   The shortest distance between the inner wall surface (20w) of the upstream side portion and the inner wall surface (21w) of the downstream side portion of the upstream side portion and the downstream side portion that are opposed to each other is the upstream side portion. The heat transfer member according to any one of claims 1 to 6, wherein the heat transfer member is set to be larger than a total dimension obtained by adding a width dimension of a cross section of the portion and a width dimension of a cross section of the downstream side portion. .   The heat transfer member according to any one of claims 1 to 7, wherein the upstream side portion and the downstream side portion have a front end surface that forms a curved surface. A pipe inner surface with which fluid flowing down inside the pipe (4; 104; 204; 304) comes into contact;
A pair of upstream sides (20), which are sides protruding so as to extend along the inner surface of the pipe, and extend so as to approach each other at an acute angle with respect to the pipe axis direction and advance toward the upstream;
A pair of sides that protrude so as to extend along the pipe inner surface downstream of the upstream side part, and extend so as to approach each other at an acute angle with respect to the pipe axis direction and progress toward the downstream, and a pair of adjacent sets A downstream side (21) of
A concave portion (22) provided inside the pair of the upstream side portion and the pair of the downstream side portion on the inner surface of the pipe and recessed from the upstream side portion and the downstream side portion;
With
A group of heat transfer promoting portions (2) including a set of the upstream side portion, a set of the downstream side portion and the concave portion is provided in a plurality of groups continuously downstream on the inner surface of the pipe,
The heat transfer promoting portion adjacent on the upstream side and the downstream side is formed by integrating the downstream side portion of the heat transfer promoting portion on the upstream side and the upstream side portion of the heat transfer promoting portion on the downstream side. Heat transfer tubes are installed as shown.   The heat transfer tube according to claim 9, wherein a plurality of groups of the heat transfer promoting portions are provided adjacent to each other in both the cross direction intersecting with the tube axis direction and the tube axis direction on the inner surface of the tube.   The heat transfer tube according to claim 9, wherein a group of the heat transfer promoting portions has a length in the tube axis direction larger than a length in a circumferential direction.   The heat transfer tube according to any one of claims 9 to 11, wherein the recess is a portion surrounded by a pair of the upstream side portions and a pair of the downstream side portions.   The heat transfer tube according to claim 12, wherein the one set of the upstream side parts and the one set of the downstream side parts are sides that exhibit a rhombus shape when the pipe inner surface is developed in a planar shape.   The creepage distance along the pipe inner surface between the inner wall surface (20w) of the upstream side portion and the inner wall surface (21w) of the downstream side portion of the upstream side portion and the downstream side portion that are opposed to each other is: 14. The method according to claim 9, wherein a total dimension of the width of the cross section of the upstream side and the width of the cross section of the downstream side is set to be larger. Heat transfer tube as described.   The heat transfer tube according to any one of claims 9 to 14, wherein the upstream side portion and the downstream side portion have a tip surface that forms a curved surface. An outer surface side groove (42, 43; 143) formed on an outer surface of the tube;
The heat transfer tube according to any one of claims 9 to 15, wherein the upstream side portion and the downstream side portion are provided on a back side of the outer surface side groove portion. The longitudinal cross-sectional shape of the recess forms a flat surface,
The projection size (d) of each of the upstream side portion and the downstream side portion with respect to the flat surface is set to be 0.1 times or less the outer diameter (D) of the pipe. The heat transfer tube according to claim 16. An inner pipe (4) through which the first fluid flows,
An outer pipe (3) that houses the inner pipe and allows a second fluid to flow down an outer flow path provided between the inner pipe and an outer surface (41) of the inner pipe;
With
The heat exchanger wherein the inner tube is the heat transfer tube according to any one of claims 9 to 17.   The heat exchanger according to claim 18, wherein the plurality of groups of the heat transfer promoting units are provided over an entire portion of the inner pipe where the first fluid and the second fluid exchange heat. Providing a tube (4; 204);
By forming a first spiral groove (42) proceeding clockwise in the tube axis direction and a second spiral groove (43) proceeding leftward in the tube axis direction on the outer surface of the tube, the tube is formed on the inner surface of the tube. Forming, in the axial direction, a first helical projection that advances clockwise and a second helical projection that advances leftward;
A method for manufacturing a heat transfer tube including: Providing an outer tube (3);
Providing an inner tube (4; 204) having an outer diameter smaller than the inner diameter of the outer tube;
By forming a first helical groove (42) proceeding clockwise in the tube axis direction and a second helical groove (43) proceeding leftward in the tube axis direction on the outer surface of the inner tube, the inner surface of the inner tube is formed. Forming a first helical protrusion that proceeds clockwise in the pipe axis direction and a second helical protrusion that proceeds leftward in the tube axis direction;
A coupling step of coupling the outer tube and the inner tube so as to form a passage between the inner surface of the outer tube and the outer surface of the inner tube;
The manufacturing method of the heat exchanger containing.

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