JP6203079B2 - Method for manufacturing twisted tube heat exchanger - Google Patents

Description

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

A torsion pipe heat exchanger that exchanges heat between water and refrigerant uses a torsion pipe having a spiral groove on the outer periphery as a water pipe, and wraps the refrigerant pipe from the outer circumference side along the spiral groove of the water pipe. It is a heat exchanger which performs heat exchange between the water which flows through, and the refrigerant which flows through the refrigerant | coolant piping.
The spiral groove has a function of generating a turbulent flow on the water side and improving the heat exchange performance by its effect.

  In such a case, for the purpose of improving the heat transfer performance, a method is known in which a flux (oxide film removing agent) is applied to a water pipe wrapped with a refrigerant pipe and then immersed in a molten solder bath. (For example, Patent Document 1).

  In addition, a low melting point solder paste is applied in advance to the bottom of the spiral groove of the water pipe, the refrigerant pipe is wound along the shape of the spiral groove on the outer periphery of the water pipe, and the water pipe spirally wound on the water pipe is There is known a method of bending a shape, flowing a high-temperature fluid in a water pipe, melting a low melting point solder paste, and heat-transfer joining the water pipe and the refrigerant pipe (for example, see Patent Document 2).

Japanese Patent No. 4435008 (Claims 1, 2) JP 2009-47394 (Abstract, FIG. 4)

  However, in the method in which the flux is applied to the water pipe wrapped around the water pipe and then immersed in the molten solder tank, not only the gap between the water pipe and the refrigerant pipe but also the refrigerant not in contact with the water pipe Solder also adheres to the outer surface of the pipe, resulting in a large amount of excess solder that does not contribute to heat transfer. Therefore, there has been a problem that extra material costs are generated.

  In addition, a method in which a low melting point solder paste is applied to a spiral groove, a coolant pipe is wound, a high temperature fluid is flowed into the water pipe, the low melting point solder paste is melted, and the water pipe and the refrigerant pipe are heat-transfer bonded. When the low melting point solder is melted, there is a problem that the low melting point solder drips and a large amount of solder remains in a portion that does not contribute to heat transfer.

  The present invention has been made to solve the above-described problems, and is effective in heat transfer contact in heat transfer joining between water piping and refrigerant piping in a torsion tube heat exchanger that performs heat exchange between water and refrigerant. An object of the present invention is to provide a method for manufacturing a twisted tube heat exchanger that can reduce the manufacturing cost while maintaining the area.

A method for manufacturing a torsion tube heat exchanger according to the present invention includes a step of winding a refrigerant pipe along a spiral groove around a water pipe serving as a core pipe having a plurality of spiral grooves on the outer periphery, At the same time or in advance of winding, only the surface where the water pipe and the refrigerant pipe face each other, the step of applying a flux to one of the water pipe and the refrigerant pipe, the water pipe and the refrigerant pipe after winding the refrigerant pipe, And a step of heat transfer joining by immersing the substrate in a molten solder bath.

  According to the manufacturing method of the twisted tube heat exchanger of the present invention, the flux is applied to one of the surfaces of the water pipe and the refrigerant pipe facing at the same time or in advance of the winding of the refrigerant pipe, The water pipe and the refrigerant pipe are immersed in a molten solder tank and heat transfer joined. At this time, the solder adheres only to the portion where the flux is applied. Therefore, the solder adheres only to the gap between the water pipe that contributes to heat transfer to which the flux is applied and the refrigerant pipe, and the outer surface of the refrigerant pipe that does not contribute to heat transfer (no flux is applied, It does not adhere to the surface that is not in contact with the piping. As a result, manufacturing costs (particularly material costs) can be reduced while maintaining an effective heat transfer contact area.

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 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 cut | disconnects and shows the twisted tube type heat exchanger manufactured with the manufacturing method of the twisted tube type heat exchanger which concerns on Embodiment 1 of this invention along a pipe axis. It is sectional drawing which cut | disconnects and shows the twisted tube type heat exchanger of a comparative example along a pipe axis. 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 process drawing which shows the manufacturing method of the twisted tube heat exchanger which concerns on Embodiment 2 of this invention.

Embodiment 1. FIG.
The present invention will be described below with reference to illustrated embodiments.
1 and 2 are process diagrams showing a method for manufacturing a twisted tube heat exchanger according to Embodiment 1 of the present invention.
As shown in FIGS. 1 and 2, the torsion tube heat exchanger according to the first embodiment of the present invention includes a torsion tube having a plurality of spiral grooves 2 on the outer periphery, that is, a water pipe 1 and a spiral to the water pipe 1. The refrigerant pipe 4 is wound along the groove 2.

  Next, the manufacturing method of the twisted tube heat exchanger which concerns on Embodiment 1 of this invention is demonstrated, referring FIG. 3 based on FIG.1 and FIG.2. First, the surface of the water pipe 1 (FIG. 1 (a)) that is a core pipe having a plurality of spiral-shaped grooves (hereinafter referred to as spiral grooves) 2 on the outer periphery, that is, the surface facing the refrigerant pipe 4, that is, the spiral of the water pipe 1. A flux 3 is applied to the groove 2 (FIG. 1B). Next, the refrigerant pipe 4 is wound along the spiral groove 2 of the water pipe 1 (FIG. 1C). Note that the flux 3 may be applied to the spiral groove 2 of the water pipe 1 simultaneously with the winding of the refrigerant pipe 4.

  Next, the water pipe 1 and the refrigerant pipe 4 after winding the refrigerant pipe are bent in a U shape to create a U-shaped assembly pipe 6A (FIG. 2A). Thereafter, the water pipe 1 and the refrigerant pipe 4 after bending, that is, the U-shaped assembly pipe 6A are immersed in a molten solder tank 7 and heat transfer joined (FIG. 2B).

FIG. 3 is a cross-sectional view of the torsion tube heat exchanger manufactured by the manufacturing method of the torsion tube heat exchanger according to the first embodiment of the present invention, cut along the tube axis. The state of solder joining of the water pipe 1 and the refrigerant pipe 4 of the vessel 6 is shown.
The solder 8 adheres only to the portion where the flux 3 is applied. In this embodiment, since the flux 3 is applied only to the spiral groove 2 of the water pipe 1, the solder 8 is placed in the gap between the water pipe 1 and the refrigerant pipe 4 that contributes to heat transfer as shown in FIG. 3. It does not adhere to the outer surface of the refrigerant pipe 4 that does not contribute to heat transfer (the surface that is not coated with the flux 3 and is not in contact with the water pipe 1).

FIG. 4 is a cross-sectional view showing the twisted tube heat exchanger of the comparative example cut along the tube axis, and the flux 3 is applied to the entire assembly tube formed by winding the refrigerant pipe 4 around the water pipe 1. The water pipe 1 and the refrigerant pipe 4 are heat-transfer joined by being immersed in a molten solder tank 7.
In the case of the twisted tube heat exchanger of this comparative example, since the flux is applied to the entire assembly tube, not only the solder 8 in the gap between the water pipe 1 and the refrigerant pipe 4 as shown in FIG. The solder 8a also adheres to the outer surface of the refrigerant pipe 4 that is not in contact with the water pipe 1, that is, the part that does not contribute to heat transfer. As described above, in the comparative example, a large amount of extra solder 8a that does not contribute to heat transfer adheres, resulting in extra material costs.

  As in the manufacturing method of the twisted tube heat exchanger according to the first embodiment of the present invention, the flux 3 is applied only to the spiral groove 2 of the water pipe 1, thereby maintaining an effective heat transfer contact area. Further, it is possible to suppress the adhesion of excess solder 8a, and it is possible to reduce manufacturing costs (particularly material costs).

Embodiment 2. FIG.
5 and 6 are process diagrams showing a method for manufacturing a torsion tube heat exchanger according to Embodiment 2 of the present invention. In each drawing, the same parts as those in Embodiment 1 are given the same reference numerals. It is.
As shown in FIGS. 5 and 6, the torsion tube heat exchanger according to the second embodiment of the present invention also includes a torsion tube having a plurality of spiral grooves 2 on the outer periphery, that is, a water pipe 1 and a spiral to the water pipe 1. The refrigerant pipe 4 is wound along the groove 2.

  Next, the manufacturing method of the twisted tube heat exchanger which concerns on Embodiment 2 of this invention is demonstrated, referring FIG. 3 based on FIG.5 and FIG.6. First, the refrigerant 3 wound around the spiral groove 2 of the water pipe 1, that is, the surface of the refrigerant pipe 4 that is drawn out from the refrigerant pipe winding bobbin 5 and wound around the spiral groove 2 is opposed to the spiral groove 2. Is applied (FIGS. 5A and 5B). Next, the refrigerant pipe 4a to which the flux 3 is applied is wound around the spiral groove 2 along the spiral groove 2 of the water pipe 1 and with the flux application surface facing the spiral groove 2 side (FIG. 5C). )). The flux 3 may be applied to the refrigerant pipe 4 simultaneously with the winding of the refrigerant pipe 4.

  Next, the water pipe 1 and the refrigerant pipe 4a after winding of the refrigerant pipe are bent into a U shape to create a U-shaped assembly pipe 6B (FIG. 6A). Thereafter, the water pipe 1 and the refrigerant pipe 4a after bending, that is, the U-shaped assembly pipe 6B are immersed in a molten solder tank 7 and heat transfer joined (FIG. 6B).

  Also in this embodiment, since the flux 3 is applied only to the surface of the refrigerant pipe 4a that faces the spiral groove 2, the solder 8 is formed between the water pipe 1 and the refrigerant pipe 4 that contribute to heat transfer as shown in FIG. It adheres only to the gaps between them, and does not adhere to the outer surface of the refrigerant pipe 4a that does not contribute to heat transfer (the surface on which the flux 3 is not applied and is not in contact with the water pipe 1).

  As in the manufacturing method of the twisted tube heat exchanger according to Embodiment 2 of the present invention, effective heat transfer contact is achieved by applying the flux 3 only to the surface facing the spiral groove 2 of the refrigerant pipe 4a. While maintaining the area, it is possible to suppress the adhesion of excess solder 8a (FIG. 4), and to reduce manufacturing costs (particularly material costs).

  1 water pipe, 2 spiral groove, 3 flux, 4,4a refrigerant pipe, 5 refrigerant pipe winding bobbin, 6 torsion pipe heat exchanger, 6A, 6B U-shaped assembly pipe, 7 molten solder bath, 8, 8a Solder.

Claims (3)

A step of winding a refrigerant pipe along the spiral groove on a water pipe that becomes a core pipe having a plurality of spiral grooves on the outer periphery;
At the same time or in advance of winding of the refrigerant pipe, a step of applying a flux to one of the water pipe and the refrigerant pipe only on the surface where the water pipe and the refrigerant pipe face each other;
The step of immersing the water pipe and the refrigerant pipe after winding the refrigerant pipe in a molten solder bath and heat transfer joining;
The manufacturing method of the twisted tube type heat exchanger characterized by having. The method for manufacturing a torsion tube heat exchanger according to claim 1, wherein a flux is applied only to the spiral groove of the water pipe. 2. The method of manufacturing a torsion tube heat exchanger according to claim 1, wherein a flux is applied only to a surface of the refrigerant pipe facing the spiral groove.

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