JP2006002979A - Electric water heater with heat exchanger and heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact heat exchanger and an electric water heater comprising the same, superior in heat exchanging performance. <P>SOLUTION: This heat exchanger comprises a hot water supply pipe 5 including a plurality of linear parts 21a and a plurality of curved parts 21b, and a refrigerant pipe 5 including a plurality of linear parts 25a and a plurality of curved parts 25b. The heat exchanger is constituted in such a state that the extending direction of the linear parts 21a and the extending direction of the linear parts 25a are approximately in parallel with each other. The plurality of linear parts 21a and the plurality of linear parts 25a are alternately formed in the direction perpendicular to the extending direction of the linear parts 21a, and at least a part of the linear parts 21a and the linear parts 25a adjacent to each other are partially bonded to each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat exchanger and an electric water heater provided with the heat exchanger.

  In the heat exchanger, a pipe through which one fluid flows and a pipe through which another fluid flows are formed, and the pipes are bonded to each other, or an intermediate member is interposed between the pipes. And other fluids exchange heat.

  For example, in Japanese Patent Application Laid-Open No. 2001-280696, as a heat exchanger for an electric water heater, at least two or more flat hot water pipes and refrigerant pipes having substantially the same outer shape in cross section as the hot water pipe are alternately stacked. In a heat exchanger in which end plates provided at both ends are fastened so that the pipes are pressed against each other by bolts and nuts, the thickness of the hot water pipe is made thicker than the thickness of the refrigerant pipe A heat exchanger is disclosed.

  This heat exchanger is formed by winding a hot water supply pipe and a refrigerant pipe spirally. Supports (end plates) are provided on both sides of the spiral body, and a heat exchanger in which the support body is formed in a spiral shape is mechanically fastened by a bolt provided in the center of the spiral body. In addition, a spring washer is inserted between the nut and the support to prevent changes in tightening force due to repeated expansion and contraction due to heat of the heat exchanger. And the heat insulating material for preventing the heat loss to the exterior is wound cylindrically on the outer periphery of the hot-water supply water tube and the refrigerant tube wound spirally.

By adopting this configuration for the heat exchanger, no significant design changes are required, the deformation of the hot water supply pipe can be suppressed at low cost, the electric heating area can be secured, the heat exchange rate does not deteriorate, reliability and durability It is disclosed that a heat exchanger excellent in performance can be provided.
JP 2001-280696 A

  In the heat exchanger disclosed in Patent Document 1 above, the hot water pipe and the refrigerant pipe are formed by being wound in a cylindrical spiral shape, and therefore there is a lower limit to the radius at which these pipes are wound. is there. That is, the hot water supply pipe and the refrigerant pipe need to be spiral with a certain radius or more. For this reason, there is a problem that the internal space surrounded by the hot water supply pipe and the refrigerant pipe becomes large, and the heat exchanger itself becomes large.

  Moreover, a support body (end plate) is formed at both ends of the spiral body, and a hot water supply pipe and a refrigerant pipe are pressed by a spring washer and upper and lower end plates. The pressing force of the spring washer is uniformly applied to each hot water supply pipe and the refrigerant pipe, but the shape of the hot water supply pipe or the refrigerant pipe is not uniform, and the tubes are not uniformly adhered to each other, and the contact thermal resistance There is a problem that becomes large. For this reason, it is necessary to lengthen the pipe lengths of the hot water supply pipe and the refrigerant pipe, and there is a problem that it is difficult to reduce the size of the heat exchanger.

  Further, in the heat exchanger disclosed in Patent Document 1 above, the hot water supply pipe and the refrigerant pipe are each processed so that the cross-sectional shape is flat. There was a problem that the tube of this was easy to deform. The heat exchange performance is not stabilized by this deformation, and there is a problem that the heat exchange performance is easily affected by the deformation of the pipe.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a small heat exchanger excellent in heat exchange performance and an electric water heater provided with the heat exchanger.

  In order to achieve the above object, a heat exchanger according to the present invention includes a first pipe including a plurality of first straight portions having linear shapes substantially parallel to each other and a plurality of linear shapes substantially parallel to each other. And a second pipe including the second straight portion. The first piping includes a plurality of first curved portions having a curved shape that connects the first straight portions to each other, and the second piping has a curved shape that connects the second straight portions to each other. A plurality of second curved portions are included. The extending direction of the first straight portion and the extending direction of the second straight portion are formed so as to be substantially parallel to each other. A plurality of the first straight portions and a plurality of the second straight portions are alternately formed in a direction perpendicular to the extending direction of the first straight portions, and the adjacent first straight portions and the second straight portions. Are at least partially joined to each other.

  In order to achieve the above object, an electric water heater according to the present invention includes the above heat exchanger.

  ADVANTAGE OF THE INVENTION According to this invention, it is excellent in heat exchange performance and can provide a small heat exchanger and an electric water heater provided with the same.

(Embodiment 1)
(Constitution)
With reference to FIGS. 1-14, the heat exchanger and electric water heater in Embodiment 1 based on this invention are demonstrated.

  FIG. 1 is a perspective view of a heat exchanger in the present embodiment. The heat exchanger in the present embodiment includes a hot water supply pipe 1 as a first pipe and a refrigerant pipe 5 as a second pipe. In the present embodiment, hot water supply pipe 1 and refrigerant pipe 5 are each formed of copper.

  FIG. 2 is a perspective view when the hot water supply pipe is extracted from the heat exchanger. The hot water supply pipe 1 includes a straight portion 21a having a linearly extending shape as the first straight portion. Hot water pipe 1 includes a curved portion 21b having a curved shape for connecting the straight portions 21a to each other as the first curved portion.

  A plurality of straight portions 21a and curved portions 21b are formed. The straight portions 21a are formed so that their extending directions are substantially parallel to each other. In the present embodiment, the curved portions 21b connected to one end of the straight portion 21a are formed so as to be substantially parallel to each other, and are connected to the other end of the straight portion 21a. The curved portions 21b are formed so as to be substantially parallel to each other.

  The hot water supply pipe 1 includes a U-shaped long pipe 1a and a U-shaped short pipe 1b each having a U-shaped planar shape. The U-shaped long tube 1a includes a straight portion 21a and a curved portion 21b, and is a long tube having a straight portion 21a. The U-shaped short tube 1b includes a straight portion 21a and a curved portion 21b, and is a short tube having the straight portion 21a. The U-shaped short tube 1b may be a tube formed only from a curved portion without including a straight portion. By connecting the U-shaped long pipe 1a and the U-shaped short pipe 1b to each other, the hot water supply water pipe 1 is formed as one communicating pipe.

  FIG. 3 shows a perspective view when the refrigerant pipe is extracted from the heat exchanger. The refrigerant pipe 5 in the present embodiment is formed from a single pipe. The refrigerant pipe 5 includes a straight portion 25a as a second straight portion and a curved portion 25b as a second curved portion. A plurality of straight portions 25a and curved portions 25b are formed. The straight portions 25a have a straight shape and are formed so that their extending directions are substantially parallel to each other. The curved portion 25b has a curved planar shape. In the present embodiment, the curved portion 25b is formed to have an arc shape. The curved portion 25b is formed so as to connect the plurality of straight portions 25a to each other.

  In FIG. 1, the extending direction of the straight portion 21 a of the hot water supply pipe 1 and the extending direction of the straight portion 25 a of the refrigerant pipe 5 are formed so as to be substantially parallel. Further, the straight portion 21a of the hot water supply pipe 1 and the straight portion 25a of the refrigerant pipe 5 are formed so as to contact each other. The refrigerant enters the refrigerant pipe 5 as indicated by an arrow 35a and exits as indicated by an arrow 35b. The refrigerant in the present embodiment is a gas. Water or hot water (hereinafter referred to as “water” or the like) enters the hot water supply pipe 1 as indicated by an arrow 31a, and water or the like exits as indicated by an arrow 31b. The curved portion 21b of the hot water supply pipe 1 and the curved portion 25b of the refrigerant pipe 5 are formed so as to intersect each other.

  As shown in FIG. 1, the inlet and outlet of the hot water pipe 1 are formed so as to face the same side. Moreover, the inlet part and outlet part of the refrigerant pipe 5 are formed so as to face the same side. The inlet part of the hot water supply pipe 1 and the outlet part of the refrigerant pipe 5 are formed so as to face opposite sides, and the outlet part of the hot water pipe 1 and the inlet part of the refrigerant pipe 5 are formed so as to face opposite sides. Yes.

  The hot water supply pipe 1 has a shape in which a pipe is wound around a quadrangular column at a predetermined interval. In other words, the hot water pipe 1 has a shape in which the spiral shape is flattened so that the planar shape is a quadrangle. Similarly, the refrigerant pipe 5 has such a shape that the pipe is wound around the quadrangular column at a constant interval. In the present embodiment, the direction in which hot water supply pipe 1 is wound and the direction in which refrigerant pipe 5 is wound are formed in opposite directions.

  FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. FIG. 4 is a cross-sectional view of the straight portion of the hot water supply pipe and the straight portion of the refrigerant pipe taken along a plane perpendicular to the extending direction of each straight portion. In the heat exchanger according to the present embodiment, in the cross section perpendicular to the extending direction of the straight portion of the hot water pipe, the straight portion of the hot water pipe 1 and the straight portion of the refrigerant pipe 5 are alternately formed, and this row includes two rows. It is formed to become. In other words, the straight portion of the hot water pipe 1 and the straight portion of the refrigerant pipe 5 are formed on two planes whose main surfaces are parallel to each other. In FIG. 4, the row in which the hot water supply pipes and the refrigerant pipes are alternately arranged has an upper row and a lower row. In each row, the hot water pipe 1 is formed so as to sandwich the refrigerant pipe 5, and the refrigerant pipe 5 is formed so as to sandwich the hot water pipe 1.

  In the present embodiment, the outer diameter of the refrigerant pipe 5 is formed to be smaller than the outer diameter of the hot water supply pipe 1. The hot water supply pipe 1 and the refrigerant pipe 5 are formed so that the cross-sectional shapes thereof are not flattened. That is, the hot water supply pipe 1 and the refrigerant pipe 5 are formed by cylindrical pipes.

  The heat exchanger according to the present embodiment is formed so that a straight line connecting two cross-sectional openings of the hot water supply pipe communicating with each other is inclined in a cross section taken along a plane perpendicular to the straight line portion of the hot water supply pipe. That is, in the cross-sectional view of FIG. 4, the extending direction of the curved portion is formed to be oblique. Alternatively, in FIG. 4, the extending direction of the curved portion is inclined with respect to the direction in which the straight portion of the hot water supply pipe and the straight portion of the refrigerant pipe are arranged.

  FIG. 5 shows an enlarged view of a portion A in FIG. The hot water supply pipe 1 and the refrigerant pipe 5 are formed so as to be fixed to each other at every other joint in the respective straight portions. In the present embodiment, one straight portion of hot water supply pipe 1 and one straight portion of refrigerant pipe 5 are fixed by brazing material 15 so as to form a pair.

  For example, in the upper row of FIG. 4, except for the hot water supply water pipe 1 at the right end, one straight part of the refrigerant pipe 5 and one straight part of the hot water supply pipe 1 are fixed in pairs in order from the right side. ing. In the lower row of FIG. 4, except for the hot water supply water pipe 1 at the left end, one straight part of the refrigerant pipe 5 and one straight part of the hot water supply pipe 1 are fixed in pairs in order from the left side. . In the present embodiment, no brazing material is disposed between the refrigerant pipe and the hot water supply pipe between these pairs.

  In FIG. 6, the perspective view when the heat exchanger in this Embodiment is covered with the heat insulating material is shown. The heat insulating material 16 is formed so that heat is not radiated to the outside. The heat insulating material 16 in the present embodiment is formed so as to surround the heat exchanger. The heat insulating material 16 is formed so that the inlet portion and the outlet portion of the hot water pipe 1 protrude from the surface. Moreover, the heat insulating material 16 is formed so that the inlet part and outlet part of the refrigerant pipe 5 may protrude from the surface.

  7 and 8 are cross-sectional views of the connection portion between the U-shaped long pipe and the U-shaped short pipe of the hot water supply pipe in the present embodiment. FIG. 7 is a cross-sectional view before connecting the U-shaped long tube and the U-shaped short tube, and FIG. 8 is a cross-sectional view when the U-shaped long tube and the U-shaped short tube are connected.

  As shown in FIG. 7, the U-shaped long pipe 1a is formed so that the inner diameter through which the fluid flows becomes the inner diameter D2, and the U-shaped short pipe 1b is formed so that the inner diameter through which the fluid flows becomes the inner diameter D1. Is formed. The inner diameter D2 is formed to be larger than the inner diameter D1. That is, in this embodiment, the inner diameter of the U-shaped long tube is formed to be larger than the inner diameter of the U-shaped short tube.

  As shown in FIG. 8, the U-shaped short tube 1b is fitted into the end of the U-shaped long tube 1a. The fluid passing through the hot water supply pipe flows in the direction indicated by the arrow 41. The hot water supply pipe in the present embodiment is formed so that the inner diameter of the pipe increases at the position where the fluid flowing through the curved portion enters the straight portion.

  The electric water heater in this embodiment includes the above-described heat exchanger. The electric water heater in this embodiment is a heat pump type electric water heater. A heat pump type electric water heater compresses a refrigerant gas such as carbon dioxide to form a high-temperature refrigerant gas, and then transfers the heat to water to heat the water. The heat exchanger in the present embodiment is formed as a heat exchanger for performing heat exchange between water and the refrigerant. That is, in the electric water heater, the heat exchanger according to the present invention is arranged in a portion where heat exchange is performed between the refrigerant and water.

(Action / Effect)
1, in the heat exchanger in the present embodiment, water or the like flows through a hot water supply water pipe 1 as a first pipe, and a refrigerant flows through a refrigerant pipe 5 as a second pipe. Heat exchange is performed between the hot water supply pipe 1 and the refrigerant pipe 5. The heat of the high-temperature refrigerant passing through the refrigerant pipe 5 is transmitted to low-temperature water passing through the hot water supply pipe 1.

  With reference to FIGS. 1 and 4, in the heat exchanger in the present embodiment, mainly in a portion where the straight portion 21a of the hot water supply pipe 1 and the straight portion 25a of the refrigerant pipe 5 are fixed by a brazing material, Heat exchange is performed between the refrigerant and water.

  The refrigerant enters the heat exchanger from the inlet of the refrigerant pipe 5 as shown by an arrow 35a, passes through the refrigerant pipe 5, and exits the heat exchanger from the outlet of the refrigerant pipe 5 as shown by an arrow 35b. The refrigerant is deprived of heat while passing through the refrigerant pipe 5, and has a high temperature at the inlet of the refrigerant pipe 5 and a low temperature at the outlet of the refrigerant pipe 5. Water or the like enters the heat exchanger from the inlet of the hot water pipe 1 as indicated by an arrow 31a, passes through the hot water pipe 1 and exits the heat exchanger from the outlet of the hot water pipe 1 as indicated by an arrow 31b. Water or the like receives heat while flowing through the hot water supply pipe 1. Water or the like is cold at the inlet of the hot water supply pipe 1 and is hot at the outlet of the hot water pipe 1.

  In the heat exchanger according to the present invention, the hot water supply pipe as the first pipe includes a straight part and a curved part, and the refrigerant pipe as the second pipe includes a straight part and a curved part. The straight line part of the hot water supply pipe and the straight line part of the refrigerant pipe are formed so as to be substantially parallel, and at least a part of the straight line part of the adjacent hot water pipe and the straight part of the refrigerant pipe is joined to each other. By adopting this configuration, the space surrounded by the first pipe or the second pipe can be reduced, and the heat exchanger can be reduced.

  In the heat exchanger according to the present embodiment, the straight part of the hot water supply pipe and the straight part of the refrigerant pipe that are paired with each other are fixed to each other by the brazing material. When the first pipe and the second pipe are brought into contact with each other, the first pipe and the second pipe are not uniformly brought into close contact with each other at each contact point, and the contact thermal resistance increases. However, as in the present embodiment, the heat transfer area between the first pipe and the second pipe can be increased by fixing the first pipe and the second pipe with the brazing material. The brazing material is excellent in heat conduction to the same extent as the member forming the pipe. For this reason, comparing the case where two pipes are brought into contact with the case where two pipes are brought into contact and further fixed by brazing, the case where the two pipes are fixed by brazing improves the heat transfer efficiency by about 10 times. be able to.

  Thus, heat transfer efficiency can be improved by fixing the 1st straight line part of the 1st piping, and the 2nd straight line part of the 2nd pipe with brazing material, and the pipe length of the 1st pipe and the 2nd pipe Each can be shortened. As a result, the heat exchanger can be further downsized. In addition, the pipe length is shortened and an inexpensive heat exchanger can be provided, and the manufacturing is facilitated and the productivity is improved.

  In the present embodiment, the straight line part of one hot water supply pipe and the straight line part of one refrigerant pipe are joined so as to form a pair. However, the present invention is not limited to this form. The hot water supply pipe and the refrigerant pipe may be fixed by a brazing material.

  In the present embodiment, the first pipe and the second pipe are fixed to each other by the brazing material. However, the present invention is not limited to this form, and even if the first pipe and the second pipe are fixed by solder. I do not care. Alternatively, the first pipe and the second pipe may be fixed by an adhesive having excellent thermal conductivity. By adopting any one of these configurations, the same operations and effects as described above can be obtained.

  In addition, when a flat pipe is used as the pipe in order to increase the contact area between the first pipe and the second pipe, the heat exchanger itself is easily deformed by the pressure of the fluid flowing through the pipe, Replacement performance is likely to change. That is, the strength of the heat exchanger is reduced by using a flat tube. However, in the heat exchanger according to the present invention, it is not necessary to use a flat tube, and a tube having a circular cross section can be used. As a result, it is possible to provide a heat exchanger that prevents deformation of the heat exchanger due to the internal pressure of the pipe. Moreover, the fluctuation | variation of the heat exchange capability by deformation | transformation of heat exchanger itself can be prevented. That is, a heat exchanger excellent in heat exchange performance can be provided.

  In addition, the heat exchanger in the present embodiment is formed such that the curved portion of the hot water supply pipe and the curved portion of the refrigerant pipe have respective circular arc shapes. Further, in a cross section perpendicular to the extending direction of the straight line portion of the hot water supply pipe, a plurality of rows in which the straight line portion of the hot water supply pipe and the straight line portion of the refrigerant pipe are alternately fixed are formed. By adopting this configuration, the first pipe and the second pipe can each be formed into a flattened spiral shape, and the heat exchanger can be downsized. Moreover, if necessary, the number of turns of the hot water supply pipe or the refrigerant pipe can be changed, and the pipe length can be easily lengthened or shortened.

  The heat exchanger in the present embodiment is formed so that a straight line connecting two cross-sectional mouths of a hot water supply water pipe communicating with each other is inclined in a cross section when cut by a plane perpendicular to the straight line portion of the hot water supply water pipe. . That is, the extending direction of the curved portion is inclined. By adopting this configuration, the thickness of the heat exchanger can be reduced. The heat exchanger is not particularly limited to this form, and is formed so that the line connecting the two openings in the cross section of the U-shaped long pipe and the direction in which the hot water supply pipe and the refrigerant pipe are alternately arranged are perpendicular to each other. May be.

  In the present embodiment, the straight line portion of the hot water supply pipe and the straight line portion of the refrigerant pipe are formed so that the alternately formed rows are two rows. This row may be formed. For example, the above-described rows may be formed in four rows, and each straight line portion may be connected by a curved portion.

  As shown in FIG. 7, the connecting portion between the U-shaped long tube and the U-shaped short tube of the hot water pipe of the heat exchanger in the present embodiment is formed so that the inner diameter increases along the direction of the fluid. . That is, the inner diameter of the tube is increased at the connection portion where the fluid is directed from the curved portion to the straight portion. 7 and 8, the inner diameter D2 is formed to be larger than the inner diameter D1. By adopting this configuration, the flow rate of the fluid flowing in the direction indicated by the arrow 41 is increased at the inner diameter D2, and the flow along the inner surface of the pipe at the straight portion is disturbed. For this reason, a heat transfer rate improves and heat exchange performance improves. Therefore, the pipe length can be further shortened, and a smaller heat exchanger can be provided.

  In the present embodiment, the inner diameter of the U-shaped short tube including the curved portion is made smaller than the inner diameter of the U-shaped long tube including the straight portion. However, the present invention is not limited to this configuration. For example, FIG. 9 and FIG. As shown, the distal end of the short tube 12b including the curved portion may be contracted to form the contracted tube portion 20.

  FIG. 9 is a cross-sectional view before the short tube 12b is connected to the long tube 12a, and FIG. 10 is a cross-sectional view when the short tube 12b is connected to the long tube 12a. The fluid flow is in the direction indicated by arrow 42. As shown in FIG. 10, a hot water pipe is formed by connecting a short tube 12b having a reduced tube portion 20 formed at the tip thereof to a long tube 12a including a straight portion. Also by adopting this configuration, it is possible to form a portion where the inner diameter of the pipe increases in the connection portion where the fluid is directed from the curved portion to the straight portion, and the heat exchange performance in the straight portion is improved as described above. .

  Further, in the present embodiment, the hot water pipe is formed with a portion where the inner diameter changes. However, the present invention is not particularly limited to this configuration, and the portion of the refrigerant pipe that transitions from the curved portion to the straight portion has a small inner diameter. A portion that changes to a large one may be formed. Alternatively, the portion with the larger inner diameter may be formed in the middle of the straight portion, in addition to the portion that transitions from the curved portion to the straight portion.

  In the present embodiment, one hot water supply pipe and one refrigerant pipe are formed so as to be joined to each other. However, the present invention is not particularly limited to this, and the number of hot water supply pipes and refrigerant pipes should be plural. Can do.

  For example, FIG. 11 is a cross-sectional view of another heat exchanger in the present embodiment, and is a cross-sectional view of a heat exchanger in which two hot water supply pipes are formed with respect to one refrigerant pipe. The hot water supply pipe 2 is formed of two pipes. As shown by arrows 32a, fluid such as water enters the inlets of the two pipes, and as shown by arrows 32b, each of the two pipes. It is formed so that fluid such as water comes out from the outlet. The refrigerant pipe 5 is formed from a single pipe. The refrigerant enters the refrigerant pipe 5 as indicated by an arrow 35a and exits from the refrigerant pipe 5 as indicated by an arrow 35b. FIG. 11 shows an example in which the number of water supply pipes is plural. Similarly, the number of refrigerant pipes may be plural.

  Thus, the heat exchanger based on this invention can make the number of 1st piping or 2nd piping arbitrary. As a result, it is possible to set an arbitrary heat exchange capacity corresponding to the heat load. Moreover, the flow volume of the fluid which flows through 1st piping or 2nd piping can be changed.

  In the present embodiment, the fluid flowing through the first pipe is a liquid, and the fluid flowing through the second pipe is a gas. However, the present invention is not limited to this configuration, and the fluid flowing through the first pipe and the second pipe is a gas. Or a liquid. Alternatively, it may be a mixed fluid of gas and liquid.

  The electric water heater in this embodiment includes the above-described heat exchanger. By adopting this configuration, the heat exchanger can be made small, and the electric water heater can be miniaturized. Moreover, the effect of the above-mentioned heat exchanger can be acquired.

(Manufacturing method of heat exchanger)
With reference to FIG. 3, FIG. 4, and FIG. 12 to FIG. 14, the manufacturing method of the heat exchanger in the present embodiment will be described.

  As shown in FIG. 3, the refrigerant | coolant pipe | tube 5 containing the linear part 25a and the curve part 25b is formed. The refrigerant pipe 5 is formed by bending a single pipe. In the bending process in the present embodiment, a metal core is put in the pipe, and a bending jig is placed on the outside, and the pipe is bent so that they are aligned with each other. In the bending process, as shown in FIG. 4, the straight portions 25a of the refrigerant tubes 5 are formed so as to be arranged in two rows. In the row | line | column of one linear part 25a, it forms so that the space | interval of linear part 25a may become substantially the same as the outer diameter of a hot water supply pipe. That is, it forms so that a hot water supply pipe | tube can be arrange | positioned between the linear parts of a refrigerant | coolant pipe | tube.

  Next, as shown in FIGS. 12 and 13, a U-shaped long pipe 1a and a U-shaped short pipe 1b, which are components of a hot water supply pipe, are formed. In the present embodiment, the U-shaped long tube 1a and the U-shaped short tube 1b are formed by bending a tube. The U-shaped long tube 1a includes a long straight portion 21a and a curved portion 21b, and the U-shaped short tube 1b is formed to include a short straight portion 21a and a curved portion 21b. The planar shapes of the curved portion 21b in the U-shaped long tube 1a and the curved portion 21b in the U-shaped short tube 1b may be different from each other. A plurality of U-shaped long tubes 1a and U-shaped short tubes 1b are formed.

  Next, as shown in FIG. 14, the U-shaped long pipe 1a is inserted between the straight portions 25a of the formed refrigerant pipe 5, and the temporary fixing is fixed by a jig. At this time, the U-shaped long tube 1a is fixed so that the straight portion 21a of the U-shaped long tube 1a and the straight portion 25a of the refrigerant tube 5 are parallel to each other. Moreover, it fixes so that the linear part 21a of the U-shaped long tube which should become a pair, and the linear part 25a of the refrigerant pipe 5 may contact.

  Next, the U-shaped short tube 1b is arranged so as to be connected to the U-shaped long tube 1a so that the U-shaped long tubes 1a are connected to each other, and the temporary fixing is fixed. Of the two upper and lower rows shown in FIG. 4, with respect to the adjacent U-shaped long tube 1a, the opening of the U-shaped long tube in one row and the opening of the U-shaped long tube in the other row are It arrange | positions so that it may connect with the short tube 1b.

  Thus, after assembling the whole and fixing the temporary fixing, paste paste, flux and brazing material, or brazing material is paired between the straight portion 21a of the hot water supply water pipe and the straight portion 25a of the refrigerant pipe 5. To place. Moreover, in a hot water supply pipe, it arrange | positions in the connection part of the U-shaped long pipe 1a and the U-shaped short pipe 1b.

  After the brazing material and the like are arranged in the heat exchanger, the temporarily fixed heat exchanger is arranged in the brazing furnace. The brazing material and the like are melted to fix each member. The heat exchanger in this Embodiment can be manufactured by brazing.

  Thus, in this embodiment, one tube is formed from one tube by bending, and the other tube is formed into a U-shaped long tube and a U-shaped short tube. Next, the U-shaped long tube of the other tube is inserted into the one tube and temporarily fixed. Next, the U-shaped short tube is temporarily fixed to the U-shaped long tube so that the U-shaped short tube becomes a tube connecting the U-shaped long tubes. Finally, each member is brazed. By adopting this method, it is possible to manufacture a heat exchanger in which the straight portions of two pipes wound in opposite directions are in contact with each other.

  In the present embodiment, the brazing of the respective members is performed collectively. However, the present invention is not limited to this embodiment, and the brazing of the respective members may be performed in a plurality of steps.

  The first pipe and the second pipe in the present embodiment are formed so that the cross-sectional shape is substantially circular. When bending a flat tube with a cross-sectional shape, the radius of curvature must be increased to maintain the strength of the tube, but by making the cross-sectional shape of the tube circular as in this embodiment, The radius of curvature of the curved portion can be reduced. As a result, it is possible to further reduce the size of the heat exchanger.

  In the present embodiment, the planar shape of the straight line portion is formed to be a straight line shape, and the planar shape of the curved line portion is formed to be an arc shape. However, the present invention is not limited to this form. It only needs to have a linear shape. For example, the planar shape of the straight line portion may be formed to wave. That is, even if a slight curve is included in the planar shape of the linear portion, it is only necessary to have a linear extending direction. Moreover, as a curved part, as long as the linear parts are connected, you may form in arbitrary planar shapes.

  In the present embodiment, the hot water supply water pipe and the refrigerant pipe are made of copper. However, the present invention is not limited to this form, and it is only necessary that each pipe is made of a material having excellent heat conduction. For example, in addition to copper, a pipe made of brass or aluminum may be formed as a hot water supply pipe or a refrigerant pipe.

(Embodiment 2)
(Constitution)
With reference to FIGS. 15 to 18, a heat exchanger and an electric water heater in Embodiment 2 based on the present invention will be described.

  FIG. 15 is a perspective view of the heat exchanger in the present embodiment. A hot water supply pipe 1 as a first pipe including a plurality of straight portions 21a substantially parallel to each other and a refrigerant pipe 5 as a second pipe including a plurality of straight portions 25a substantially parallel to each other, the extending direction of the straight portions 21a, In the vertical direction, the plurality of straight portions 21a and the plurality of straight portions 25a are alternately formed, and at least some of them are joined to each other, as in the heat exchanger in the first embodiment.

  In the heat exchanger in the present embodiment, the refrigerant pipe 5 includes a U-shaped long pipe 5a and a U-shaped short pipe 5b. In the first embodiment, the refrigerant pipe is formed from one pipe, but the refrigerant pipe in the present embodiment is formed by joining two types of pipes.

  FIG. 16 is a perspective view of the U-shaped long pipe 5a among the components of the refrigerant pipe 5. The U-shaped long tube 5a includes a straight portion 25a and a curved portion 25b. The straight part 25a is a part formed so as to extend linearly. The curved portion 25b is a portion that connects the straight portions 25a. The U-shaped long pipe 5a includes two straight portions 25a, and the straight portions 25a are formed so that their extending directions are substantially parallel to each other. The curved portion 25b is formed so that the planar shape is an arc shape.

  FIG. 17 is a perspective view of the U-shaped short pipe 5b among the components of the refrigerant pipe 5. The U-shaped short tube 5b includes a straight portion 25a formed so as to extend linearly and a curved portion 25b connecting the straight portions 25a. The curved portion 25b is formed so that the planar shape is an arc shape.

  The refrigerant pipe 5 is formed by connecting a U-shaped long pipe 5a and a U-shaped short pipe 5b. The refrigerant pipe 5 has a configuration in which straight portions are arranged in two rows, as in the refrigerant pipe in the first embodiment (see FIG. 3). The heat exchanger in the present embodiment is the same as the heat exchanger in the first embodiment except that the refrigerant tube 5 is formed using the U-shaped long tube 5a and the U-shaped short tube 5b.

  The electric water heater in this embodiment includes the above-described heat exchanger. Since other configurations are the same as those in the first embodiment, description thereof will not be repeated here.

(Operation, effect and manufacturing method)
The heat exchanger in the present embodiment is different from the heat exchanger in the first embodiment in the configuration of the refrigerant pipe and the method of manufacturing the heat exchanger.

  FIG. 18 is an explanatory diagram of a method for manufacturing a heat exchanger in the present embodiment. FIG. 18 is a perspective view for explaining the manufacturing method. First, as shown in FIGS. 16 and 17, a U-shaped long tube 5a and a U-shaped short tube 5b for forming a refrigerant tube are formed. In the present embodiment, the U-shaped long tube 5a and the U-shaped short tube 5b are formed by bending the tube. Moreover, the U-shaped long pipe 1a and the U-shaped short pipe 1b for forming a hot water supply pipe are prepared similarly to Embodiment 1 (refer FIG. 12 and FIG. 13).

  Next, as shown in FIG. 18, the U-shaped long pipe 1a of the hot water supply pipe and the U-shaped long pipe 5a of the refrigerant pipe are alternately arranged so that the straight portions forming a pair come into contact with each other in the respective straight portions. And temporarily fix it. At this time, the opening side of the U-shaped long pipe 1a of the hot water supply pipe and the opening side of the U-shaped long pipe 5a of the refrigerant pipe are arranged in opposite directions. That is, the curved portion 21b of the U-shaped long tube 1a and the curved portion 25b of the U-shaped long tube 5a are arranged so as to be opposite to each other. Further, in a cross section perpendicular to the extending direction of the straight portion 21a of the U-shaped long tube 1a, there is a row in which the straight portions 21a of the U-shaped long tube 1a and the straight portions 25a of the U-shaped long tube 5a are alternately arranged. Arrange them in two rows.

  Next, the U-shaped short tube 1b is arranged so that the openings of the adjacent U-shaped long tubes 1a are connected by the U-shaped short tube 1b, and the temporary fixing is fixed. In the connection of the U-shaped short tube 1b, the opening of the U-shaped long tube 1a in one row and the opening of the U-shaped long tube 1a in the other row are fixed to each other. In a plurality of places, the U-shaped long pipes 1a are connected to each other by using the U-shaped short pipe 1b to form one pipe to be a hot water supply water pipe.

  Further, on the side of the refrigerant tube where the opening of the U-shaped long tube 5a is formed, the U-shaped short tube 5b is connected so that the openings of the U-shaped long tubes 5a adjacent to each other are connected by the U-shaped short tube 5b. To fix the temporary fixing. In the connection of the U-shaped short tube 5b, the opening of the U-shaped long tube 5a in one row and the opening of the U-shaped long tube 5a in the other row are fixed to each other. In a plurality of locations, the U-shaped long pipes 5b are connected to each other to form one pipe to be a refrigerant pipe.

  Next, paste solder or the like is bonded to the heat exchanger fixed and fixed temporarily, a joint portion between the straight portion 21a of the hot water pipe 1 and the straight portion 25a of the refrigerant tube 5, the U-shaped long tube 1a and the U-shaped short tube. It arrange | positions in the connection part of the connection part with 1b and the U-shaped long tube 5a and the U-shaped short pipe 5b. Next, brazing is performed by placing the temporarily secured heat exchanger inside the brazing furnace. The U-shaped long pipe 1a and the U-shaped short pipe 1b are connected and fixed to form a hot water supply water pipe. Further, the U-shaped long pipe 5a and the U-shaped short pipe 5b are connected and fixed to form a refrigerant pipe. Further, of the portions where the straight portion 21a of the hot water supply pipe 1 and the straight portion 25a of the refrigerant pipe 5 are in contact with each other, some are fixed to each other by a brazing material (see FIG. 5).

  Thus, the heat exchanger in this Embodiment can be manufactured by forming 1st piping and 2nd piping, respectively using two types of U-shaped pipes. In addition, there is no step of forming a refrigerant tube having a flat spiral shape from a single tube, and the heat exchanger of the present invention can be manufactured more easily than the manufacturing method in the first embodiment.

  In the present embodiment, the first pipe and the second pipe are formed with two types of U-shaped pipes. However, the present invention is not particularly limited to this form, and a pipe obtained by dividing the first pipe and the second pipe is formed and connected. You may combine them. For example, the first pipe or the second pipe may be formed by forming a pipe obtained by dividing the first pipe or the second pipe into a straight part and a curved part and connecting these pipes.

  As in the first embodiment, it is preferable to include a portion where the inner diameter of the tube changes from a small one to a large one in the connection portion where the fluid flows from the curved portion to the straight portion of the heat exchanger.

  Since other operations, effects, and manufacturing methods are the same as those in the first embodiment, description thereof will not be repeated here.

(Embodiment 3)
(Constitution)
With reference to FIGS. 19 to 25, a heat exchanger and an electric water heater in Embodiment 3 according to the present invention will be described.

  FIG. 19 is a perspective view of the heat exchanger in the present embodiment, and FIG. 20 is a cross-sectional view taken along the line XX-XX in FIG.

  The heat exchanger in the present embodiment includes a hot water supply pipe 3 and a refrigerant pipe 6. The hot water supply pipe 3 includes a straight portion 23a and a curved portion 23b. The refrigerant pipe 6 includes a straight portion 26a and a curved portion 26b. The hot water supply pipe 3 is formed of a U-shaped long pipe 3a and a U-shaped short pipe 3b. The refrigerant pipe 6 is formed from a single pipe.

  As shown in FIGS. 19 and 20, the straight portions 23 a of the hot water pipe 3 and the straight portions 26 a of the refrigerant pipe 6 are alternately arranged in a cross section perpendicular to the extending direction of the straight portion 23 a of the hot water pipe 3. The rows are formed in two rows.

  FIG. 21 shows an enlarged view of a portion B in FIG. The heat exchanger in the first embodiment is that the contact portions where the straight portions of the straight portion 23a of the hot water pipe 3 and the straight portion 26a of the refrigerant tube 6 are paired are fixed to each other by the brazing material 15. It is the same.

  As shown in FIGS. 19 and 20, water or the like enters hot water pipe 3 as shown by arrow 33a and exits hot water pipe 3 as shown by arrow 33b. Further, the refrigerant enters the refrigerant pipe 6 as indicated by an arrow 36a and exits from the refrigerant pipe 6 as indicated by an arrow 36b.

  The hot water supply pipe 3 and the refrigerant pipe 5 of the heat exchanger in the present embodiment have a flattened spiral shape such that each pipe is wound around the rectangular parallelepiped at a constant interval. Further, the direction in which the hot water supply pipe 3 is wound and the direction in which the refrigerant pipe 5 is wound are formed in the same direction. Further, the curved portion of the hot water supply pipe 3 and the curved portion of the refrigerant pipe 5 are formed so as to extend in parallel with each other without intersecting.

  The inlet of the hot water supply pipe 3 and the outlet of the refrigerant pipe 5 are formed so as to face the same side, and are further formed adjacent to each other. Further, the outlet of the hot water supply pipe 3 and the inlet of the refrigerant pipe 6 are formed so as to face the same side, and are further formed adjacent to each other.

  Here, attention is paid to the direction of the flow of the fluid flowing through the hot water supply pipe 3 and the direction of the flow of the fluid flowing through the refrigerant pipe 5. In the hot water supply pipe 3 and the refrigerant pipe 6 adjacent to each other, the direction of the fluid flowing through the hot water supply pipe 3 and the direction of the fluid flowing through the refrigerant pipe 6 are formed to be opposite to each other. That is, the heat exchanger in the present embodiment is formed so that the fluid in the hot water supply pipe 1 and the fluid in the refrigerant pipe 5 are opposed to each other.

  For example, in FIG. 20, in the upper row and the lower row in which the straight portions of the hot water pipe 3 and the straight portions of the refrigerant pipe 6 are alternately arranged, one is sequentially arranged from the left in FIG. Paying attention to the pair of the refrigerant pipe 6 and one hot water pipe 3, the direction of the flow of the straight part of the refrigerant pipe 6 shown by the arrow 36b is opposite to the direction of the flow of the straight part of the hot water pipe 3 shown by the arrow 33a. It is formed to become. As described above, the fluid is formed so that the fluid flows in the opposite directions in the straight line portion of the refrigerant pipe and the straight line portion of the hot water supply pipe which are paired.

  The electric water heater in this embodiment includes the above-described heat exchanger. Since other configurations are the same as those in the first embodiment, description thereof will not be repeated here.

(Action / Effect)
Embodiment 1 is that at least a part of the contact portion between the straight line portion 23a of the hot water supply pipe 3 and the straight line portion 26a of the refrigerant pipe 6 is joined and fixed to each other by brazing, and heat exchange is performed in each straight line portion It is the same as the heat exchanger in In the heat exchanger of this Embodiment, it forms so that the flow of the hot water supply pipe | tube and the refrigerant | coolant pipe | tube joined and fixed by brazing may become a countercurrent flow.

  If the flow of the two fluids of the first pipe and the second pipe are made parallel, the temperature difference between the outlet of the low temperature side fluid and the outlet of the high temperature side fluid becomes small, resulting in poor heat exchange efficiency. Become. On the other hand, by making the flow of the fluid that performs heat exchange countercurrent, the temperature difference between the fluids can always be increased, and the temperature efficiency can be improved. As a result, the pipe length of the heat exchanger can be shortened, and the heat exchanger can be further downsized.

  Since other operations and effects are the same as those in the first embodiment, description thereof will not be repeated here.

(Production method)
With reference to FIGS. 22 to 25, a method for manufacturing the heat exchanger in the present embodiment will be described.

  As shown in FIG. 22, by bending the pipe that becomes the refrigerant pipe, a portion that becomes the curved portion 26b is formed, and the refrigerant pipe 6 that includes the straight portion 26a and the curved portion 26b is formed. The linear portions 26a are formed so that the extending directions thereof are parallel to each other. In addition, in a cross section obtained by cutting along a cross section perpendicular to the extending direction of the straight portion 26a, the straight portions 26a are formed in two rows.

  Next, as shown in FIGS. 23 and 24, a pipe which is a component part of the hot water supply pipe is formed. FIG. 23 is a perspective view of the U-shaped long tube 3a, and FIG. 24 is a perspective view of the U-shaped short tube 3b. The U-shaped long tube 3a and the U-shaped short tube 3b are formed by the same method as in the first embodiment. In forming the U-shaped short tube 3b, the U-shaped long tubes 3a are formed so that they can be connected later.

  FIG. 25 is a perspective view illustrating a method for manufacturing a heat exchanger in the present embodiment. The straight portion 26a of the refrigerant pipe 6 and the straight portion 23a of the U-shaped long tube 3a are arranged so as to contact each other at a paired portion, and the temporary fixing is fixed. Moreover, it arrange | positions so that the extension direction of the linear part 26a and the extension direction of the linear part 23a may become substantially parallel. Furthermore, in this Embodiment, it arrange | positions so that the inlet_port | entrance part of a hot water supply pipe | tube and the exit part of a refrigerant | coolant pipe | tube may mutually join. Moreover, it arrange | positions so that the exit part of a hot water supply pipe and the entrance part of a refrigerant pipe may mutually join.

  Next, fixing the temporary fixing of the U-shaped short tube 3b so that the opening of one U-shaped long tube 3a and the opening of another U-shaped long tube 3a adjacent to each other are connected by the U-shaped short tube 3b. To do. In the arrangement of the U-shaped short tube 3b, the opening in one row of the U-shaped long tube 3a and the other of the two rows arranged in a cross section perpendicular to the longitudinal direction of the straight portion of the U-shaped long tube 3a It arrange | positions so that it may connect with the opening part of this row | line | column. In addition, the U-shaped short pipe 3b is arranged so that the fluid flow in the hot water pipe and the fluid flow in the refrigerant pipe face each other in the straight part of the hot water pipe and the straight part of the refrigerant pipe. Further, the U-shaped short tube 3b is arranged so that the curved portion 23b of the U-shaped short tube 3b and the curved portion 26b of the refrigerant tube 6 are substantially parallel to each other.

  It is the same as the manufacturing method of the heat exchanger in the first embodiment that the brazing is performed by placing a paste brazing or the like at the joint portion between the corresponding straight portion of the hot water pipe and the straight portion of the refrigerant pipe. .

  Since other manufacturing methods are the same as those of the heat exchanger manufacturing method according to the first embodiment, description thereof will not be repeated here.

(Embodiment 4)
(Constitution)
With reference to FIGS. 26 to 31, a heat exchanger and an electric water heater in Embodiment 4 according to the present invention will be described.

  FIG. 26 is a perspective view of the heat exchanger in the present embodiment. The heat exchanger in the present embodiment includes a hot water supply pipe 4 as a first pipe and a refrigerant pipe 7 as a second pipe. The hot water supply pipe 4 is formed of a U-shaped short pipe 4b and a U-shaped long pipe 4a as a first U-shaped pipe. The refrigerant tube 7 is formed of a U-shaped short tube 7b and a U-shaped long tube 7a as a second U-shaped tube.

  The hot water pipe 4 includes a straight portion 24a and a curved portion 24b, and the refrigerant tube 7 includes a straight portion 27a and a curved portion 27b. The straight portion 24a of the hot water supply pipe 4 and the straight portion 27a of the refrigerant pipe 7 are arranged so that the extending directions are parallel to each other.

  FIG. 27 is a cross-sectional view taken along the line XXVII-XXVII in FIG. In the cross section perpendicular to the extending direction of the straight portion 24 a of the hot water supply pipe 4, the hot water supply pipes 4 and the refrigerant pipes 7 are formed so that two rows are alternately arranged.

  26 and 27, in the heat exchanger according to the present embodiment, the U-shaped long tube 4a of hot water supply water pipe 4 and the U-shaped long pipe 7a of refrigerant pipe 7 have respective U-shaped shapes. Are formed to be substantially the same, and the U-shaped long tube 4a and the U-shaped long tube 7a are alternately fixed so as to overlap the U-shaped shape.

  The U-shaped short pipe 4b of the hot water supply pipe 4 and the U-shaped short pipe 7b of the refrigerant pipe 7 are arranged so that the curved portion 24b and the curved portion 27b face the same direction. The U-shaped short tube 4b is formed so as to connect the opening of one U-shaped long tube 4a and the opening of another U-shaped long tube 4a adjacent to each other. The U-shaped short pipe 4b includes, in a cross section perpendicular to the extending direction of the straight portion of the hot water pipe, an opening of the U-shaped long pipe 4a in one row and an opening of the U-shaped long tube 4a in the other row. It is formed to connect.

  The U-shaped short tube 7b is formed so as to connect the opening of one U-shaped long tube 7a and the opening of another U-shaped long tube 7a adjacent to each other. The U-shaped short tube 7b is formed so as to connect the opening of the U-shaped long tube 7a in one row and the opening of the U-shaped long tube 7a in the other row.

  As shown in FIG. 26, the heat exchanger in the present embodiment is formed such that water or the like enters the hot water supply pipe 4 as indicated by an arrow 34a, and water or the like exits from the hot water supply pipe 4 as indicated by an arrow 34b. ing. Further, the refrigerant pipe 7 is formed such that the refrigerant enters the refrigerant pipe 7 as indicated by an arrow 37a and the refrigerant exits from the refrigerant pipe 7 as indicated by an arrow 37b.

  In FIG. 26, the inlet of the hot water supply pipe 4 and the outlet of the refrigerant pipe 7 are formed so as to face the same side, and further adjacent to each other. Further, the outlet of the hot water supply pipe 4 and the inlet of the refrigerant pipe 7 are formed so as to face each other, and are further formed adjacent to each other. The heat exchanger in the present embodiment is formed so that the fluid flow in hot water supply pipe 4 and the fluid flow in refrigerant pipe 7 face each other. Thus, the heat exchanger in this Embodiment is formed so that the fluid which flows through an inside may become a counterflow.

  FIG. 28 shows an enlarged cross-sectional view of a portion C shown in FIG. In the present embodiment, the hot water supply pipe 4 and the refrigerant pipe 7 are adjacent to each other in the respective straight portions, and the corresponding pair portions are fixed by the brazing material 15. For example, in the upper row shown in FIG. 27, one straight portion of the refrigerant pipe 7 and one straight portion of the hot water supply pipe 4 are fixed to each other by the brazing material 15 in order from the left. Further, in the lower row, one straight portion of the refrigerant pipe 7 and one straight portion of the hot water supply pipe 4 are fixed to each other by the brazing material 15 in order from the left.

  In the hot water supply pipe 4, the U-shaped long pipe 4a and the U-shaped short pipe 4b are fixed to each other by a brazing material. In the refrigerant pipe 7, the U-shaped long pipe 7a and the U-shaped short pipe 7b are fixed to each other by a brazing material.

  The electric water heater in this embodiment includes the above-described heat exchanger. Since other configurations are the same as those in the first embodiment, description thereof will not be repeated here.

(Action / Effect)
Referring to FIGS. 26 and 27, in the heat exchanger of the present embodiment, high-temperature refrigerant flows through refrigerant pipe 7, and low-temperature water or the like flows through hot-water supply water pipe 4. Heat exchange is performed between the refrigerant pipe 7 and the hot water supply pipe 4.

  In the present embodiment, the heat exchange is performed between the straight portion 24 a of the hot water supply pipe 4 and the straight portion 27 a of the refrigerant pipe 7, and the curved portion 24 b of the hot water supply pipe 4 and the curved portion 27 b of the refrigerant pipe 7. Also performed between. Thus, heat exchange is performed in the entire portion where the hot water supply pipe 4 and the refrigerant pipe 7 are in contact with each other.

  In the heat exchanger according to the present embodiment, a hot water supply pipe as a first pipe includes a U-shaped long pipe as a first U-shaped pipe, and a refrigerant pipe as a second pipe is a U-shaped long as a second U-shaped pipe. Including tubes. The U-shaped long pipe of the hot water supply pipe and the U-shaped long pipe of the refrigerant pipe are formed so that the U-shapes are substantially the same size, and are arranged so as to overlap the U-shapes. By adopting this configuration, the fluid flowing through the first pipe and the fluid flowing through the second pipe can be made to counter flow, and the temperature efficiency is improved.

  In addition, as will be described later, the heat exchanger in the present embodiment can be easily formed by combining a U-shaped long pipe of a hot water supply pipe and a U-shaped long pipe of a refrigerant pipe, thereby improving productivity.

  Since other operations and effects are the same as those in the first embodiment, description thereof will not be repeated here.

(Production method)
With reference to FIGS. 29 to 31, a method for manufacturing the heat exchanger in the present embodiment will be described.

  As shown in FIG. 29, a U-shaped long pipe 7a of the refrigerant pipe is formed. The U-shaped long tube 7a is formed so as to include two straight portions 27a and a curved portion 27b that connects the straight portions 27a. The curved portion 27b is formed so that the planar shape is an arc shape. The two straight portions 27a are formed so that their extending directions are parallel to each other. Next, a U-shaped short pipe of the refrigerant pipe is formed. In forming the U-shaped short tube of the refrigerant tube, the U-shaped short tube is formed so as to include a curved portion (not shown).

  Next, as shown in FIG. 30, the U-shaped long pipe 4a of the hot water supply pipe is formed. The U-shaped long tube 4a is formed so as to include two straight portions 24a and a curved portion 24b that connects the straight portions 24a. The two straight portions 24a are formed so that their extending directions are parallel to each other. The curved portion 24b is formed so that the planar shape is an arc shape. The U-shaped long tube 4a of the hot water supply tube and the U-shaped long tube 7a of the refrigerant tube are formed so that the U-shaped shape of the planar shape is almost the same size. Next, a U-shaped short pipe of a hot water supply pipe is formed. In the formation of the U-shaped short pipe of the hot water supply pipe, the U-shaped short pipe is formed so as to include a curved portion (not shown).

  Next, as shown in FIG. 31, the U-shaped long pipe 4a of the hot water supply pipe and the U-shaped long pipe 7a of the refrigerant pipe are arranged so that the U-shapes overlap each other, and the temporary fixing is fixed. Temporary fixing is performed by arranging the opening of the U-shaped long tube 4a and the opening of the U-shaped long tube 7a so as to face the same side.

  Next, using the U-shaped short tube 4b, the U-shaped short tube 4b is arranged so as to connect the U-shaped long tubes 4a to each other, and the temporary fixing is fixed. In the arrangement of the U-shaped short tube 4b, as shown in FIG. 31, the opening of one U-shaped long tube 4a and the opening of another adjacent U-shaped long tube 4a are connected to the U-shaped short tube 4b. Use them to connect. In the arrangement of the U-shaped short tubes 4b, the openings of one row of the U-shaped long tubes 4a and the openings of the other row of the adjacent U-shaped long tubes 4a are arranged to be connected. In this way, one communicating pipe to be a hot water pipe is formed.

  Next, the U-shaped long tubes 7a of the refrigerant tubes are connected by a U-shaped short tube 7b. In the arrangement of the U-shaped short tubes 7b, as shown in FIG. 31, the openings in the rows above one U-shaped long tube 7a, and the openings in the rows below the other adjacent U-shaped long tubes 7a. Arrange to connect. In this way, one communicating pipe that is to be the refrigerant pipe is formed.

  In the arrangement of the U-shaped short tube 4b and the U-shaped short tube 7b, the U-shaped short tube 4b and the U-shaped short tube 7b are arranged so as not to cross each other. It arrange | positions so that the extension direction of each curve part may become mutually parallel.

  Next, paste wax or the like is placed on the fixed part. In the present embodiment, a paste braze or the like is disposed at the contact portion between the pair of hot water supply pipe and the refrigerant pipe among the contact portions between the straight line portion of the hot water supply pipe and the straight line portion of the refrigerant pipe. In the hot water supply pipe, a paste wax or the like is disposed at the joint between the U-shaped long pipe 4a and the U-shaped short pipe 4b. In the refrigerant pipe, a paste wax or the like is disposed at a joint portion between the U-shaped long pipe 7a and the U-shaped short pipe 7b. After this, the temporarily secured heat exchanger is placed inside the brazing furnace, and each part is fixed with a brazing material.

  Thus, the heat exchanger in this Embodiment can be easily formed by combining a U-shaped long tube and a U-shaped short tube.

  In the present embodiment, brazing material is disposed at the contact portion between the straight portion of the hot water pipe and the straight portion of the refrigerant tube. However, the present invention is not limited to this configuration, and brazing material is also disposed at the curved portion. Then, the curved portion of the hot water supply pipe and the curved portion of the refrigerant pipe may be fixed by a brazing material.

  Since other manufacturing methods are the same as those in the first embodiment, description thereof will not be repeated here.

  In all the embodiments described above, a small-diameter pipe is used as the refrigerant pipe, and a large-diameter pipe is used as the hot water supply pipe. However, the present invention is not limited to this, and the diameter of the refrigerant pipe and the hot water pipe The diameters of the refrigerant pipes may be substantially the same, or the diameter of the refrigerant pipe may be larger than the diameter of the hot water supply pipe. That is, the first pipe and the second pipe may be formed so that any diameter becomes larger.

  Further, in all the above embodiments, the heat exchanger between the refrigerant used in the heat pump in which the compressor is formed and the hot water supply pipe through which water for supplying hot water flows is described. However, the present invention can be applied to any heat exchanger.

  For example, some hot water heaters include a heat exchanger in which a high-temperature fluid and a low-temperature fluid are liquids such as water, and the present invention can be applied to this heat exchanger. In particular, the present invention can be applied to a heat exchanger used for reheating a bath in an electric water heater. In this case, for example, high-temperature water or the like flows through the first pipe, and the low-temperature water or the like flowing through the second pipe can be warmed. Furthermore, the heat exchanger based on this invention can be applied about the heat exchanger of arbitrary apparatuses not only in a water heater.

  In addition, the said embodiment disclosed this time is an illustration in all the points, Comprising: It is not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and includes all modifications within the scope and meaning equivalent to the terms of the claims.

1 is a perspective view of a heat exchanger according to Embodiment 1. FIG. 3 is a perspective view of a hot water supply pipe of the heat exchanger according to Embodiment 1. FIG. 3 is a perspective view of a refrigerant pipe of the heat exchanger in Embodiment 1. FIG. 3 is a cross-sectional view of the heat exchanger in Embodiment 1. FIG. 2 is a partial enlarged cross-sectional view of a heat exchanger in Embodiment 1. FIG. It is a perspective view when the heat insulating material is arrange | positioned around the heat exchanger in Embodiment 1. FIG. 2 is an enlarged cross-sectional view of a connection portion between a U-shaped long tube and a U-shaped short tube in Embodiment 1. FIG. It is sectional drawing when the U-shaped long tube and U-shaped short tube in Embodiment 1 are made to fit. 4 is an enlarged cross-sectional view of a connection portion between another U-shaped long tube and a U-shaped short tube in Embodiment 1. FIG. It is sectional drawing when the other U-shaped long pipe and U-shaped short pipe in Embodiment 1 are fitted. It is sectional drawing of the other heat exchanger in Embodiment 1. FIG. FIG. 3 is a first process explanatory diagram of the method of manufacturing a heat exchanger in the first embodiment. FIG. 4 is a second process explanatory diagram of the method of manufacturing the heat exchanger in the first embodiment. FIG. 4 is a third process explanatory diagram of the method of manufacturing the heat exchanger in the first embodiment. It is a perspective view of the heat exchanger in Embodiment 2. FIG. 10 is a first process explanatory diagram of a method for manufacturing a heat exchanger in Embodiment 2. FIG. 10 is a second process explanatory diagram of the method of manufacturing the heat exchanger in the second embodiment. FIG. 10 is a third process explanatory diagram of the method of manufacturing the heat exchanger in the second embodiment. 6 is a perspective view of a heat exchanger according to Embodiment 3. FIG. 6 is a cross-sectional view of a heat exchanger according to Embodiment 3. FIG. 6 is a partial enlarged cross-sectional view of a heat exchanger according to Embodiment 3. FIG. FIG. 11 is a first process explanatory diagram of a method for manufacturing a heat exchanger in a third embodiment. FIG. 10 is a second process explanatory diagram of the heat exchanger manufacturing method according to Embodiment 3. FIG. 10 is a third process explanatory diagram of the heat exchanger manufacturing method according to Embodiment 3. FIG. 10 is a fourth process explanatory diagram of the heat exchanger manufacturing method according to Embodiment 3. It is a perspective view of the heat exchanger in Embodiment 4. It is sectional drawing of the heat exchanger in Embodiment 4. FIG. FIG. 6 is a partial enlarged cross-sectional view of a heat exchanger in a fourth embodiment. It is 1st process explanatory drawing of the manufacturing method of the heat exchanger in Embodiment 4. It is 2nd process explanatory drawing of the manufacturing method of the heat exchanger in Embodiment 4. FIG. FIG. 10 is a third process explanatory diagram of the method of manufacturing a heat exchanger in the fourth embodiment.

Explanation of symbols

  1, 2, 3, 4 Hot water pipe, 1a, 3a, 4a, 5a, 7a U-shaped long pipe, 1b, 3b, 4b, 5b, 7b U-shaped short pipe, 5, 6, 7 Refrigerant pipe, 12a long pipe, 12b short pipe, 15 brazing material, 16 heat insulating material, 20 contraction pipe part, 21a, 23a, 24a, 25a, 26a, 27a straight line part, 21b, 23b, 24b, 25b, 26b, 27b curved part, 31a, 31b, 32a 32b, 33a, 33b, 34a, 34b, 35a, 35b, 36a, 36b, 37a, 37b, 41, 42 Arrows.

Claims (8)

A first pipe including a plurality of first straight portions having linear shapes substantially parallel to each other;
A second pipe including a plurality of second straight portions having linear shapes substantially parallel to each other;
The first pipe includes a plurality of first curved portions having a curvilinear shape connecting the first straight portions to each other,
The second pipe includes a plurality of second curved portions having a curvilinear shape connecting the second straight portions to each other,
The extending direction of the first straight portion and the extending direction of the second straight portion are formed so as to be substantially parallel to each other,
In a direction perpendicular to the extending direction of the first linear portion, a plurality of the first linear portions and a plurality of the second linear portions are alternately formed,
A heat exchanger in which at least a part of the adjacent first straight portion and the second straight portion are joined to each other.   2. The heat exchanger according to claim 1, wherein at least a part of the adjacent first straight portion and the second straight portion are fixed to each other by solder or brazing material. The first curved portion and the second curved portion are formed so that a planar shape is an arc shape,
The cross section perpendicular to the extending direction of the first straight line portion is formed so that there are a plurality of rows in which the first straight line portions and the second straight line portions are alternately joined. The heat exchanger as described in. Formed such that an inlet of the first pipe and an outlet of the second pipe are adjacent to each other;
The heat exchanger according to any one of claims 1 to 3, wherein an outlet of the first pipe and an inlet of the second pipe are formed adjacent to each other. The first pipe includes a plurality of first U-shaped pipes,
The second pipe includes a plurality of second U-shaped pipes,
The first U-shaped tube and the second U-shaped tube are formed so that the U-shaped shapes are substantially the same size.
The heat exchanger according to any one of claims 1 to 4, wherein the first U-shaped tube and the second U-shaped tube are alternately arranged so as to overlap the U-shaped shape. In at least one of the connection portion where the fluid is directed from the first curved portion to the first straight portion, or the first straight portion,
The heat exchanger according to any one of claims 1 to 5, including a portion in which the inner diameter of the first pipe is increased. In at least one of the connection portion where the fluid is directed from the second curved portion to the second straight portion, or the second straight portion,
The heat exchanger according to any one of claims 1 to 6, including a portion in which the inner diameter of the second pipe is increased.   An electric water heater comprising the heat exchanger according to any one of claims 1 to 7.

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