Manufacturing method for hot water storage tank

Abstract

To provide a welding method that can easily weld a heat exchange intermediate socket and a heat exchange pipe to an upper mirror, and can restrain corrosion caused by a gap.SOLUTION: A manufacturing method for a hot water storage tank according to the present disclosure sequentially performs: a step of welding a heat exchange intermediate socket 31 to a heat exchange pipe 30; a step of welding a heat exchange socket 32 to the heat exchange pipe 30; a step of inserting the heat exchange pipe 30 into a heat exchange pipe attachment hole 14 of an upper mirror 11, and positioning the heat exchange intermediate socket 31; and a step of performing butt welding of the upper mirror 11 and the heat exchange intermediate socket 31 from a surface side of the upper mirror 11.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to a method for manufacturing a hot water tank. [Background technology]

[0002] Patent Document 1 discloses a hot water storage tank for a hot water heating system that is provided with an internal heat exchanger inside the tank. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-257585 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a welding method that can easily weld a heat exchange intermediate socket and a heat exchange pipe to an upper head and can suppress corrosion due to gaps. [Means for solving the problem]

[0005] The manufacturing method of a hot water storage tank in the present disclosure is for manufacturing a hot water storage tank comprising a main body, an upper mirror and a lower mirror which close the top and bottom surfaces of the main body, an internal heat exchanger housed inside the main body, and a heat exchange pipe which is attached to the upper mirror via a heat exchange intermediate socket and has a heat exchange socket which allows a medium to flow through the internal heat exchanger, and sequentially includes a step of welding the heat exchange intermediate socket to the heat exchange pipe, a step of welding the heat exchange socket to the heat exchange pipe, a step of inserting the heat exchange pipe into a heat exchange pipe mounting hole of the upper mirror and positioning the heat exchange intermediate socket, and a step of butt-welding the upper mirror and the heat exchange intermediate socket from the surface side of the upper mirror. Effect of the Invention

[0006] According to the manufacturing method of the hot water storage tank of the present disclosure, a step of welding a heat exchange intermediate socket to the heat exchange pipe and a step of welding a heat exchange socket to the heat exchange pipe are performed before a step of welding the heat exchange pipe to the upper mirror, so that when welding the heat exchange socket and the heat exchange intermediate socket to the heat exchange pipe, a welding work space can be secured, and the welding work can be easily and appropriately performed. In addition, since the welding work can be appropriately performed, it is possible to suppress the occurrence of a gap between the heat exchange pipe and the heat exchange intermediate socket. Therefore, it is possible to suppress corrosion due to the gap. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a front view of a hot water tank according to a first embodiment; [Diagram 2] FIG. 1 is a front view showing an upper mirror and an internal heat exchanger of a hot water tank according to a first embodiment; [Diagram 3] FIG. 1 is a front view showing an internal heat exchanger according to a first embodiment; [Figure 4] FIG. 1 is a perspective view of an upper mirror in the first embodiment; [Diagram 5] FIG. 3 is a cross-sectional view of a portion of the upper mirror in the first embodiment; [Figure 6] FIG. 1 is a cross-sectional view of an upper head with a heat exchange pipe attached in the first embodiment. [Figure 7] FIG. 1 is a front view of a lower head in the first embodiment; [Figure 8] FIG. 1 is a perspective view showing a water supply pipe according to a first embodiment; [Figure 9] FIG. 1 is a perspective view showing a heat exchange pipe according to a first embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] (The knowledge and other information that formed the basis of this disclosure) At the time the inventors came up with this disclosure, the following procedure was proposed for connecting the upper mirror and the heat exchange pipe connected to the internal heat exchanger in a hot water storage tank for a hot water heating system equipped with an internal heat exchanger. First, the heat exchange intermediate socket is welded to the upper mirror. Next, the end of the internal heat exchanger pipe is inserted from inside the upper mirror and the heat exchange intermediate socket is welded to the end of the internal heat exchanger pipe. Next, the heat exchange socket is welded to the end of the internal heat exchanger pipe located on the outside of the upper mirror.

[0009] Generally, the surface of the upper mirror is curved, so when welding the heat exchange intermediate socket to the upper mirror, it is necessary to weld along the curved surface of the upper mirror. Therefore, it is difficult to secure a sufficient welding work space. In addition, after welding the heat exchange intermediate socket to the pipe tip of the internal heat exchanger, it is necessary to weld the heat exchange socket to the pipe tip, but in this case, it is difficult to secure a sufficient welding work space. In addition, since the end of the pipe of the internal heat exchanger is inserted into the heat exchange intermediate socket welded from the inside of the upper mirror, the inner diameter of the heat exchange intermediate socket needs to be larger than the outer diameter of the end of the pipe, and a gap is generated between the outer diameter of the end of the pipe of the internal heat exchanger and the inner diameter of the socket. The inventors discovered a problem that corrosion may occur from this gap, and in order to solve this problem, the subject of the present disclosure has been constituted. The present disclosure provides a welding method that can easily weld a heat exchange intermediate socket and a heat exchange pipe to an upper head and can suppress corrosion due to gaps.

[0010] Hereinafter, the embodiments will be described in detail with reference to the drawings. However, more detailed description than necessary may be omitted. For example, detailed description of already well-known matters or duplicate description of substantially the same configuration may be omitted. It should be noted that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0011] (Embodiment 1) Hereinafter, the first embodiment will be described with reference to the drawings. [1-1. Configuration] [1-1-1. Hot water tank configuration] FIG. 1 is a front view of a hot water storage tank manufactured using the welding method of the present disclosure. FIG. 2 is a front view showing an upper mirror and an internal heat exchanger portion of a hot water storage tank in embodiment 1. FIG. 3 is a front view showing the internal heat exchanger in embodiment 1. FIG. 4 is a perspective view of the upper mirror in embodiment 1. FIG. 5 is a cross-sectional view of a portion of the upper mirror in embodiment 1. FIG. 6 is a cross-sectional view of the upper mirror with a heat exchange pipe attached in embodiment 1. FIG. 7 is a front view of the lower mirror in embodiment 1.

[0012] As shown in FIG. 1, the hot water tank 1 includes a substantially cylindrical main body 10, an upper mirror 11 that closes the upper end of the main body 10, and a lower mirror 12 that closes the lower end of the main body 10. As shown in FIG. 2, the main body 10 accommodates an internal heat exchanger 20 disposed along the inner circumferential surface of the main body 10 . The internal heat exchanger 20 is composed of an internal heat exchange pipe 21 formed by winding a long pipe in a spiral shape along the inner surface of the main body 10, a medium inlet pipe 22 extending linearly upward from the lower end of the internal heat exchange pipe 21, and a medium outlet pipe 23 extending upward from the upper end of the heat exchange section. The medium circulating through a medium circuit consisting of a compressor, a condenser, medium piping, etc. (not shown) is passed sequentially through a medium inlet pipe 22, an internal heat exchange pipe 21, and a medium outlet pipe 23, thereby performing heat exchange between the medium in the internal heat exchanger 20 and the water stored in the hot water storage tank 1.

[0013] Two heat exchange pipes 30 are provided penetrating the upper mirror 11. The upper end of the medium inlet pipe 22 is connected to the lower end of one of the heat exchange pipes 30. The upper end of the medium outlet pipe 23 is connected to the lower end of the other heat exchange pipe 30. 3, 4 and 5, a flat surface 13 is formed at each of the insertion portions of the two heat exchange pipes 30 of the upper mirror 11. The flat surface 13 is formed with a heat exchange pipe mounting hole 14 for inserting the heat exchange pipe 30 therethrough. A heat exchange intermediate socket 31 is attached to the flat surface 13 at the midpoint of the axial direction of each heat exchange pipe 30. A heat exchange socket 32 ​​is attached to the upper end of each heat exchange pipe 30 to connect piping that constitutes a medium circulation circuit. The outer diameter of the heat exchange socket 32 ​​is smaller than the outer diameter of the heat exchange intermediate socket 31 . The outer diameter of the heat exchange intermediate socket is formed to be substantially the same as the inner diameter of the heat exchange pipe mounting hole 14 .

[0014] As shown in FIG. 3, a water supply pipe 40 is provided in the upper mirror 11 so as to penetrate therethrough. A flat surface 15 is formed at the portion of the upper mirror 11 where the water supply pipe 40 is inserted. A water supply socket 41 is attached to the flat surface 15 at the midpoint of the water supply pipe 40 in the axial direction.

[0015] The lower end of the water supply pipe 40 is connected to the upper end of a water supply pipe 42 that extends in the vertical direction of the main body 10. The water supply pipe 42 extends downward from the main body 10, and the lower end of the water supply pipe 42 is located near the lower mirror 12. Furthermore, as shown in FIG. 7, a lower water pipe 50 for allowing water to flow is attached to the lower head 12.

[0016] [1-2. Hot water tank manufacturing method] Next, a method for manufacturing the hot water storage tank 1 in the first embodiment will be described. Fig. 8 is a perspective view showing the water supply pipe 40 in the first embodiment. Fig. 9 is a perspective view showing the heat exchange pipe 30 in the first embodiment.

[0017] First, as shown in FIG. 8, the water supply pipe 40 and the water supply socket 41 are joined by welding. By welding the water supply pipe 40 to the water supply socket 41 before welding the water supply pipe 40 to the upper mirror 11, sufficient welding work space can be secured and the welding work can be performed easily. This makes it possible to obtain the water supply pipe 40 with the water supply socket 41 fixed thereto by welding.

[0018] Next, the heat exchange pipe 30 and the heat exchange intermediate socket 31 are joined by welding. By welding the heat exchange pipe 30 and the heat exchange intermediate socket 31 to each other before welding the heat exchange pipe 30 to the upper mirror 11, a sufficient welding work space can be secured and the welding work can be easily performed. Next, the heat exchange pipe 30 and the heat exchange socket 32 ​​are joined by welding, whereby the heat exchange pipe 30 in which the heat exchange intermediate socket 31 and the heat exchange socket 32 ​​are fixed by welding can be obtained.

[0019] Next, the water supply pipe 40 to which the water supply socket 41 is welded is attached to the upper mirror 11. The lower end of the water supply pipe 40 to which the water supply socket 41 is welded is inserted from above the upper mirror 11, and the water supply socket 41 is positioned on the flat surface 13. In this state, the outer periphery of the water supply socket 41 is butt-welded from the top surface side of the upper mirror 11, and the water supply socket 41 is fixed to the upper mirror 11. In this case, since the upper mirror 11 is provided with the flat surface 13, welding can be performed while the water supply socket 41 is stably held, and welding can be performed without gaps.

[0020] Next, the heat exchange pipe 30 to which the heat exchange socket 32 ​​and the heat exchange intermediate socket 31 are welded is attached to the upper mirror 11 . As shown in Figure 6, a heat exchange pipe 30 to which a heat exchange intermediate socket 31 and a heat exchange socket 32 ​​are welded is inserted from above the upper mirror 11, and the heat exchange intermediate socket 31 is positioned in the heat exchange pipe mounting hole 14 formed in the flat surface 13 of the upper mirror 11. In this state, butt welding is performed between the outer circumferential portion of the heat exchange intermediate socket 31 and the heat exchange pipe mounting hole 14 (indicated by a circle in Figure 6) from the upper surface side of the upper mirror 11, thereby fixing the heat exchange intermediate socket 31 to the upper mirror 11.

[0021] In this case, since the upper mirror 11 is provided with the flat surface 13, welding can be performed in a state in which the heat exchange intermediate socket 31 is stably held, and welding can be performed without gaps. In this embodiment, the outer diameter of the heat exchange socket 32 ​​is formed smaller than the outer diameter of the heat exchange intermediate socket 31. Therefore, when welding the heat exchange intermediate socket 31 and the upper mirror 11, the heat exchange socket 32 ​​does not get in the way, a large welding work space can be secured, and welding can be performed easily.

[0022] After the water supply pipe 40 and the heat exchange pipe 30 are fixed to the upper mirror 11 by welding, the upper end of the medium inlet pipe 22 and the upper end of the medium outlet pipe 23 of the internal heat exchanger 20 are connected to the lower end of the heat exchange pipe 30 by welding. Additionally, the upper end of the water supply pipe 42 is connected to the lower end of the water supply pipe 40 by welding. Next, the lower water pipe 50 is connected to the lower head 12 by welding.

[0023] Thereafter, both sides of the flat plate-like main body 10 are welded together to form the main body 10 into a cylindrical shape. Then, the internal heat exchanger 20 is inserted inside the main body 10, and the upper end of the main body 10 is fixed to the upper head 11 by welding, and the lower end of the main body 10 is fixed to the lower head 12 by welding. Thus, in this embodiment, welding can be performed in all welding steps while ensuring a large welding work space. Through the above steps, the hot water tank 1 is completed.

[0024] [1-3. Effects, etc.] As described above, the manufacturing method of the hot water storage tank 1 in this embodiment sequentially includes the steps of welding the heat exchange intermediate socket 31 to the heat exchange pipe 30, welding the heat exchange socket 32 ​​to the heat exchange pipe 30, inserting the heat exchange pipe 30 into the heat exchange pipe mounting hole 14 of the upper mirror 11 and positioning the heat exchange intermediate socket 31, and butt-welding the upper mirror 11 and the heat exchange intermediate socket 31 from the surface side of the upper mirror 11. As a result, before the process of welding the heat exchange pipe 30 to the upper mirror 11, the process of welding the heat exchange intermediate socket 31 to the heat exchange pipe 30 and the process of welding the heat exchange socket 32 ​​to the heat exchange pipe 30 are performed, so that when welding the heat exchange socket 32 ​​and the heat exchange intermediate socket 31 to the heat exchange pipe 30, welding work space can be secured and the welding work can be performed easily and appropriately. In addition, since the welding work can be performed appropriately, it is possible to prevent a gap from being generated between the heat exchange pipe 30 and the heat exchange intermediate socket 31. Therefore, it is possible to prevent corrosion due to the gap.

[0025] In addition, the manufacturing method of the hot water storage tank 1 in this embodiment further includes a step of welding the heat exchange pipe 30 to the medium inlet pipe 22 and the medium outlet pipe 23 (pipes) of the internal heat exchanger 20 after welding the heat exchange pipe 30 to the heat exchange intermediate socket 31. This allows the heat exchange pipe 30 to be welded to the upper mirror 11 before welding the medium inlet pipe 22 and medium outlet pipe 23 of the internal heat exchanger 20 to the heat exchange pipe 30, so that the welding work for the heat exchange pipe 30 can be performed without the internal heat exchanger 20 getting in the way.

[0026] In addition, in the manufacturing method of the hot water storage tank 1 in this embodiment, the outer diameter of the heat exchange socket 32 ​​is formed smaller than the outer diameter of the heat exchange intermediate socket 31 . As a result, when welding the heat exchange intermediate socket 31 and the upper mirror 11, the heat exchange socket 32 ​​does not get in the way, a large welding work space can be secured, and welding can be easily performed.

[0027] In the manufacturing method of hot water storage tank 1 in this embodiment, the periphery of heat exchange pipe mounting hole 14 of upper mirror 11 is formed into flat surface 13 that is approximately perpendicular to the axial direction of main body 10. Thus, by providing the flat surface 13 on the upper mirror 11, welding can be performed while the heat exchange intermediate socket 31 is stably held, and welding can be performed without gaps.

[0028] (Other embodiments) As described above, the first embodiment has been described as an example of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. In addition, it is also possible to combine the components described in the first embodiment to create new embodiments.

[0029] In embodiment 1, the outer diameter of the heat exchange intermediate socket is formed to be approximately the same as the inner diameter of the heat exchange pipe mounting hole 14, and the heat exchange intermediate socket is fixed to the flat portion 13 of the upper mirror 11 by butt welding at the boundary between this heat exchange intermediate socket 31 and the heat exchange pipe mounting hole 14, but the present disclosure is not limited to this. For example, the outer diameter of the heat exchange intermediate socket 31 may be formed larger than the inner diameter of the heat exchange pipe mounting hole 14, and welding may be performed with the heat exchange intermediate socket 31 placed on the flat portion 13.

[0030] [Configuration supported by the above embodiment] The above embodiment supports the following configurations.

[0031] (Additional Note) (Technology 1) In a manufacturing method for a hot water storage tank for manufacturing a hot water storage tank comprising a main body, an upper mirror and a lower mirror which close the top and bottom surfaces of the main body, an internal heat exchanger housed inside the main body, and a heat exchange pipe which is attached to the upper mirror via a heat exchange intermediate socket and has a heat exchange socket which allows a medium to flow through the internal heat exchanger, the manufacturing method for a hot water storage tank sequentially carries out the steps of welding the heat exchange intermediate socket to the heat exchange pipe, welding the heat exchange socket to the heat exchange pipe, inserting the heat exchange pipe into a heat exchange pipe mounting hole of the upper mirror and positioning the heat exchange intermediate socket, and butt-welding the upper mirror and the heat exchange intermediate socket from the surface side of the upper mirror. According to this, before the process of welding the heat exchange pipe to the upper mirror, a process of welding the heat exchange intermediate socket to the heat exchange pipe and a process of welding the heat exchange socket to the heat exchange pipe are performed.Therefore, when welding the heat exchange socket and the heat exchange intermediate socket to the heat exchange pipe, welding work space can be secured, and the welding work can be performed easily and appropriately. In addition, since the welding work can be performed appropriately, it is possible to prevent the occurrence of a gap between the heat exchange pipe and the heat exchange intermediate socket, thereby preventing corrosion due to the gap.

[0032] (Technology 2) The method for manufacturing a hot water storage tank described in Technology 1 further includes a step of welding the heat exchange pipe and the heat exchange intermediate socket together, and then welding the heat exchange pipe and the pipe of the internal heat exchanger together. According to this, the heat exchange pipe can be welded to the upper mirror before welding the internal heat exchanger pipe to the heat exchange pipe, so that the welding work for the heat exchange pipe can be performed without the internal heat exchanger getting in the way.

[0033] (Technical Technique 3) The method for manufacturing a hot water tank according to Technical Technique 1, wherein an outer diameter of the heat exchange socket is smaller than an outer diameter of the heat exchange intermediate socket. According to this, when welding the heat exchange intermediate socket and the upper mirror, the heat exchange socket does not get in the way, a large welding work space can be secured, and welding can be performed easily.

[0034] (Technical 4) A method for manufacturing a hot water tank according to Technical Claim 1, in which the periphery of the heat exchange pipe mounting hole of the upper head is formed into a flat surface approximately perpendicular to the axial direction of the main body. According to this, by providing a flat surface on the upper mirror, welding can be performed while the heat exchange intermediate socket is stably held, and welding can be performed without gaps. [Industrial Applicability]

[0035] The present disclosure is suitably applicable to a welding method that can easily weld a heat exchange intermediate socket and a heat exchange pipe to an upper head and can suppress corrosion due to gaps. [Explanation of symbols]

[0036] 1 Hot water tank 10 Main unit 11 Upper mirror 12 Lower mirror 13 Flat surface 14 Heat exchange pipe mounting hole 15 flat surface 20 Internal heat exchanger 21 Internal heat exchange pipe 22 Media introduction pipe 23 Media outlet pipe 30 Heat exchange pipe 31 Heat exchange intermediate socket 32 Heat exchange socket 40 Water Supply Pipe 41 Water supply socket 42 Water Supply Pipe 50 Lower water pipe

Claims

1. A method for manufacturing a hot water storage tank, the hot water storage tank comprising: a main body; an upper mirror and a lower mirror closing the upper and lower surfaces of the main body; an internal heat exchanger housed inside the main body; and a heat exchange pipe attached to the upper mirror via a heat exchange intermediate socket and having a heat exchange socket for flowing a medium through the internal heat exchanger, the method comprising the steps of: welding the heat exchange intermediate socket to the heat exchange pipe; welding the heat exchange socket to the heat exchange pipe; a step of inserting the heat exchange pipe into a heat exchange pipe mounting hole of the upper mirror and positioning the heat exchange intermediate socket; and butt-welding the upper mirror and the heat exchange intermediate socket from the front surface side of the upper mirror. A method for manufacturing a hot water tank.

2. The method further includes a step of welding the heat exchange pipe and the internal heat exchanger pipe after welding the heat exchange pipe and the heat exchange intermediate socket. A method for manufacturing the hot water tank according to claim 1.

3. The outer diameter of the heat exchange socket is smaller than the outer diameter of the heat exchange intermediate socket. A method for manufacturing the hot water tank according to claim 1.

4. The periphery of the heat exchange pipe mounting hole of the upper mirror is formed into a flat surface that is substantially perpendicular to the axial direction of the main body. A method for manufacturing the hot water tank according to claim 1.

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