JP2013066907A - Twisted tube heat exchanger and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve heat transfer performance by enabling an inner tube serving as a core tube and an outer tube to be brought into close contact with each other without applying high pressure to the interior of the inner tube.SOLUTION: A plurality of lines of spiral ridges 1a are formed so as to be higher than the outer tube 2 on the inner tube 1 serving as the core tube on the outer periphery of which the outer tube 2 is wound; an assembled tube is manufactured by winding the outer tube 2 on the inner tube 1 along the spiral groove 1b which is formed between the spiral ridges 1a; a core bar 4 is inserted into the inner tube 1 of the manufactured assembled tube and also a caulking implement 3 which can be diametrically enlarged and reduced is attached to the outer periphery of the assembled tube; and an external force is applied so that the diameter of the caulking implement 3 is made smaller. By caulking parts where the spiral ridge 1a is projected from the outer tube 2 which is wound on the spiral groove 1a of the inner tube 1 so that a cavity 1d which becomes a flow passage is left, the inner tube 1 forms the outer tube 2 in such a manner that the outer tube 2 is held from both sides of the axis, and the inner tube 1 and the outer tube 2 are closely joined.

Description

  The present invention relates to a twisted tube heat exchanger for exchanging heat between water and a refrigerant, and more particularly to a heat exchanger in which a refrigerant tube is wound around an outer periphery of a water tube serving as a core tube, and a method for manufacturing the heat exchanger.

  Conventionally, in a heat exchanger in which a refrigerant pipe is wound around the outer circumference of a water pipe serving as a core pipe, for the purpose of improving heat transfer performance, a water pipe serving as a core pipe and a refrigerant pipe wound spirally around the outer circumference are provided. As a method of closely adhering, expand the pipe by applying a high hydraulic pressure to the water pipe (straight pipe) that becomes the core pipe, or expand the pipe through the expansion die inside the water pipe that becomes the core pipe. There is a type in which a water pipe of a core pipe and a refrigerant pipe wound around the outer circumference thereof are closely joined without being used (for example, see Patent Document 1).

  In addition, the large diameter pipe is provided with a spiral groove and a protrusion on its edge, the small diameter pipe is embedded in the large diameter pipe groove, and the protrusion is crushed from the left and right sides of the small diameter pipe with a die or a roller. There is one in which the tube is fixed (for example, see Patent Document 2).

  In addition, there is a type in which a fin having a diameter smaller than the fin height is fixed to the finned tube by tilting the fin of the tube with the spiral fin in one direction by drawing or the like (for example, see Patent Document 3).

Japanese Patent Laid-Open No. 2004-093057 (FIGS. 2 to 5) Japanese Patent Laying-Open No. 2005-076915 (FIG. 12 and FIG. 14) Japanese Patent Laying-Open No. 2004-190922 (FIG. 5)

However, the water pipe (straight pipe) that becomes the core pipe is expanded by applying a high hydraulic pressure, or the water pipe that becomes the core pipe is expanded through the expansion die, and the water pipe of the core pipe and its outer periphery are expanded. In the case where the refrigerant tube wound around is tightly joined, the core tube is expanded until the surface contact is originally made only with the line contact, so the tube is expanded at a very high pressure. However, there is a concern that the water pipe of the core pipe is destroyed by increasing the pressure.
In addition, if the refrigerant pipe is loosely wound, the water pipe and the refrigerant pipe do not adhere well even if the pipe is expanded at a high pressure, and a gap is formed between the water pipe and the refrigerant pipe, which becomes a thermal resistance and does not improve the heat transfer performance. There was a problem.

  In addition, the large diameter pipe is provided with a spiral groove and a protrusion on its edge, the small diameter pipe is embedded in the large diameter pipe groove, and the protrusion is crushed from the left and right sides of the small diameter pipe with a die or a roller. In the case where the tube is fixed, there is no cavity serving as a flow path in the caulking projection, and the heat transfer performance does not increase so much.

  In addition, even if a pipe with a spiral fin is tilted in one direction by drawing or the like, and a circular pipe having a diameter smaller than the fin height is fixed to the finned pipe, it flows into the fin to be caulked. There were no cavities for the road, and the heat transfer performance did not increase so much.

  The present invention has been made in order to solve the above-described problems. The inner tube and the outer tube can be brought into close contact with each other without applying high pressure to the inside of the inner tube serving as the core tube, and the heat transfer performance is improved. It aims to be able to improve.

  The torsion tube heat exchanger according to the present invention comprises an inner tube that becomes a core tube having a plurality of spiral peaks and spiral grooves on an outer peripheral surface, and an outer tube that is wound along the spiral groove of the inner tube. In the torsion tube heat exchanger provided, the inner tube has a higher height of the spiral mountain than the outer tube wound around the spiral groove, and a portion protruding from the spiral groove of the spiral mountain becomes a flow path inside. It is crimped so as to leave a cavity and is formed so as to wrap the outer tube.

  Further, the manufacturing method of the torsion tube heat exchanger according to the present invention forms a plurality of spiral ridges on the inner tube that is a core tube around which the outer tube is wound so as to be higher than the outer tube. Create an assembly tube by winding an outer tube along the spiral groove formed between the spiral peaks on the tube, insert a mandrel into the inner tube of the created assembly tube, and Attach a caulking jig whose diameter can be expanded and contracted, apply external force so that the diameter of the caulking jig becomes smaller, and pass the part where the spiral mountain protrudes from the outer pipe wound around the spiral groove of the inner pipe The outer tube is formed so as to be wrapped from both sides sandwiching the axis by the inner tube, and the inner tube and the outer tube are tightly joined.

  In the torsion tube heat exchanger of the present invention, a plurality of spiral ridges are formed on the inner tube, which is a core tube around which the outer tube is wound, so as to be higher than the outer tube. After the outer tube is wound along the spiral groove formed between the inner tube and the assembly tube is created, the cavity protruding from the spiral groove of the spiral mountain of the inner tube remains inside the cavity. By caulking, the inner tube is formed so as to wrap the outer tube from both sides sandwiching its axis, and the inner tube and the outer tube are tightly joined. The tube and the outer tube can be brought into close contact with each other, and the crimped portion of the inner tube also becomes a flow path, so that the heat transfer performance can be improved.

It is process drawing which shows the manufacturing method of the twisted tube type heat exchanger which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the mode of the inner tube | pipe and outer tube | pipe at the time of the manufacturing process of the twisted tube type heat exchanger which concerns on Embodiment 1 of this invention. It is process drawing which shows the manufacturing method of the twisted tube heat exchanger which concerns on Embodiment 2 of this invention. It is sectional drawing which shows the mode of the inner tube | pipe and outer tube | pipe at the time of the manufacturing process of the twisted tube type heat exchanger which concerns on Embodiment 2 of this invention.

Embodiment 1. FIG.
FIG. 1 is a process diagram illustrating a manufacturing method of a torsion tube heat exchanger according to Embodiment 1 of the present invention, and FIG. 2 illustrates an inner tube and a manufacturing process of the torsion tube heat exchanger according to Embodiment 1 of the present invention. It is sectional drawing which shows the mode of an outer tube | pipe.

  As shown in FIGS. 1 and 2, the torsion tube heat exchanger 6A according to the first embodiment of the present invention includes an inner tube that is a core tube having a plurality of spiral ridges 1a and a spiral groove 1b, that is, a water tube 1 and a spiral tube. The outer tube wound around the groove 1b, that is, a plurality of refrigerant tubes 2 is formed. FIG. 2 shows an axial cross section of the water pipe 1.

  Next, the manufacturing method of the twisted tube heat exchanger which concerns on Embodiment 1 of this invention is demonstrated, referring FIG. 2 based on FIG. First, a plurality of spiral ridges 1 a are formed on the water pipe 1 around which the refrigerant pipe 2 is wound so as to be higher than the refrigerant pipe 2. At this time, the position of the hollow inside the spiral mountain 1a is also formed so as to be higher than the refrigerant pipe 2. Next, the refrigerant pipe 2 is wound around a plurality of spiral grooves 1b formed between the spiral peaks 1a of the water pipe 1 to create an assembly pipe (FIG. 1 (a)). Next, the mandrel 4 is inserted into the water tube 1, and the crimping jig 3 is attached to the outer periphery of the water tube 1 (FIGS. 1B and 2A). The caulking jig 3 can be configured, for example, by winding a belt-like plate in a spring shape. Thereafter, an external force is applied so that the diameter of the caulking jig 3 is reduced, and a cavity 1d that becomes a flow path remains in a portion where the spiral mountain 1a protrudes from the refrigerant pipe 2 wound around the spiral groove 1b of the water pipe 1. As a result, the water pipe 1 and the refrigerant pipe 2 are tightly joined to obtain the torsion pipe heat exchanger 6A (FIGS. 1 (c), (d), FIGS. 2 (b), (c)).

  Since the torsion tube heat exchanger according to the first embodiment of the present invention is manufactured by the above manufacturing method, a force is applied to the spiral mountain 1a from the outside in the radial direction to the inside by the caulking jig 3 at the time of caulking. It is done. For this reason, the spiral crests 1a located on both sides of the refrigerant pipe of the water pipe 1 are uniformly plastically deformed left and right so as to wrap the refrigerant pipe 2, and even if the winding of the refrigerant pipe 2 is somewhat loose, the plastic crest 1a The portion 1c wraps the refrigerant pipe 2 from both sides of the axis, and presses the refrigerant pipe 2 from the outside, so that the water pipe 1 and the refrigerant pipe 2 are in close contact with each other without a gap. Thereby, the contact area of the water pipe 1 and the refrigerant pipe 2 increases, and heat transfer performance improves.

  Further, at the time of the caulking, the plastic deformation portion 1c of the spiral mountain 1a is caulked so that the cavity 1d remains therein, so that the cavity 1d becomes a flow path, and the water pipe 1 and the refrigerant pipe 2 are brought into close contact and contact by caulking. Combined with the area increasing effect, the heat transfer performance is greatly improved.

    Furthermore, since no pressure is applied to the water pipe 1, the water pipe 1 is not ruptured, yield is improved, and manufacturing costs can be reduced.

Embodiment 2. FIG.
FIG. 3 is a process diagram showing a manufacturing method of a twisted tube heat exchanger according to Embodiment 2 of the present invention, and FIG. It is sectional drawing which shows the mode of an outer tube. In each figure, the same reference numerals are given to the same parts as those in the first embodiment.

  As shown in FIGS. 3 and 4, the torsion tube heat exchanger 6B according to the second embodiment includes an inner tube that is a core tube having a plurality of spiral peaks 1a and a spiral groove 1b, that is, a water tube 1 and a spiral groove 1b. It is comprised with the outer tube | pipe wound around along, ie, a plurality of refrigerant tubes 2. FIG. 4 shows an axial cross section of the water pipe 1.

  Next, the manufacturing method of the twisted tube heat exchanger which concerns on Embodiment 2 of this invention is demonstrated, referring FIG. 4 based on FIG. First, a plurality of spiral ridges 1 a are formed on the water pipe 1 around which the refrigerant pipe 2 is wound so as to be higher than the refrigerant pipe 2. At this time, the position of the hollow inside the spiral mountain 1a is also formed so as to be higher than the refrigerant pipe 2. Next, the refrigerant pipe 2 is wound around a plurality of spiral grooves 1b formed between the spiral peaks 1a of the water pipe 1 to create an assembly pipe (FIG. 3A). Next, the water pipe 1 around which the refrigerant pipe 2 is wound is passed through the caulking die 5 from one end side (FIGS. 3B, 4A and 4B). As a result, the portion where the spiral mountain 1a protrudes from the refrigerant tube 2 wound around the spiral groove 1b of the water tube 1 is caulked so that the cavity 1f serving as a flow path remains inside, and the water tube 1 and the refrigerant tube 2 are in close contact. The torsion tube heat exchanger 6B is obtained by joining them (FIGS. 3B, 3C, 4B, 4C).

  Since the torsion tube heat exchanger according to the second embodiment of the present invention is manufactured by the above manufacturing method, at the time of caulking, a force is applied to the spiral mountain 1a from the one end side in the axial direction by the caulking die 5 to the other end side. Added. For this reason, the helical crest 1a of the water pipe 1 is plastically deformed so as to wrap the refrigerant pipe 2 from one side of the axis, and even if the winding of the refrigerant pipe 2 is somewhat loose, the plastic deformation portion 1c of the helical crest 1a is The refrigerant pipe 2 is wrapped from one side across the axis, and the refrigerant pipe 2 is pressed from the outside, and the water pipe 1 and the refrigerant pipe 2 are in close contact with each other without any gap. Thereby, the contact area of the water pipe 1 and the refrigerant pipe 2 increases, and heat transfer performance improves. That is, almost the same effect as that obtained when the caulking jig of the first embodiment is used can be obtained.

  Further, at the time of the caulking, the plastic deformation portion 1e of the spiral mountain 1a is caulked so that the cavity 1f remains therein, so that the cavity 1f serves as a flow path, and the water pipe 1 and the refrigerant pipe 2 are brought into close contact and contact by caulking. Combined with the area increasing effect, the heat transfer performance is greatly improved.

  Furthermore, since no pressure is applied to the water pipe 1, the water pipe 1 is not ruptured, yield is improved, and manufacturing costs can be reduced.

  1 water pipe (inner pipe that becomes the core pipe), 1a spiral mountain, 1b spiral groove, 1c, 1e plastic deformation part, 1d, 1f cavity, 2 refrigerant pipe (outer pipe), 3 crimping jig, 4 core metal, 5 crimping die, 6A, 6B Twisted tube heat exchanger.

Claims (5)

In a torsion tube heat exchanger comprising an inner tube that becomes a core tube having a plurality of spiral peaks and a spiral groove on the outer peripheral surface, and an outer tube wound around the spiral groove of the inner tube,
The inner tube has a higher height of the spiral mountain than the outer tube wound around the spiral groove, and a portion protruding from the spiral groove of the spiral mountain remains in the cavity serving as a flow path. A torsion tube heat exchanger, wherein the torsion tube heat exchanger is formed so as to wrap around the outer tube.   The torsion tube heat exchanger according to claim 1, wherein the spiral crest of the inner tube is formed so as to wrap the outer tube from both sides sandwiching the axis thereof by the caulking.   2. The torsion tube heat exchanger according to claim 1, wherein the spiral crest of the inner tube is formed so as to wrap the outer tube from one side sandwiching the axis thereof by the caulking. Forming a plurality of spiral ridges on the inner tube, which is a core tube around which the outer tube is wound, so as to be higher than the outer tube;
Winding the outer tube along the spiral groove formed between the spiral ridges on the inner tube to create an assembly tube;
Inserting a mandrel into the inner tube of the assembled tube created, and attaching a caulking jig whose diameter can be expanded and contracted to the outer periphery of the assembled tube;
An external force is applied so that the diameter of the caulking jig becomes smaller, and a cavity that becomes a flow path remains in a portion where the spiral mountain protrudes from the outer tube wound around the spiral groove of the inner tube. By caulking, the outer tube is formed by the inner tube so as to be wrapped from both sides sandwiching the axis, and the inner tube and the outer tube are tightly joined, and
The manufacturing method of the twisted tube type heat exchanger characterized by having. Forming a plurality of spiral ridges on the inner tube, which is a core tube around which the outer tube is wound, so as to be higher than the outer tube;
Winding the outer tube along the spiral groove formed between the spiral ridges on the inner tube to create an assembly tube;
The prepared assembly pipe is passed through a caulking die from one end side, and the part where the spiral mountain protrudes from the outer pipe wound around the spiral groove of the inner pipe is caulked so that a cavity serving as a flow path remains in the inside. Forming the outer tube so as to be wrapped from one side of the axis sandwiched by the inner tube, and bonding the inner tube and the outer tube tightly;
The manufacturing method of the twisted tube type heat exchanger characterized by having.

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