JP2010071550A - Heat exchanger - Google Patents

Abstract

A lightweight and highly efficient heat exchanger is provided.
A heat exchanger includes a plurality of first heat transfer tubes through which a first fluid flows, and a plurality of second heat transfer tubes through which a second fluid to be exchanged with the first fluid flows. The first heat transfer tube 13 has a vortex shape. The second heat transfer tube 14 has a vortex shape corresponding to the first heat transfer tube 13 so that the locus of the center of the first heat transfer tube 13 and the locus of the center of the second heat transfer tube 14 are in translational symmetry. Have. The first heat transfer tubes 13 and the second heat transfer tubes 14 are alternately stacked so as to contact each other along the longitudinal direction of each heat transfer tube.
[Selection] Figure 1

Description

  The present invention relates to a heat exchanger.

  In conventional heat pump hot water heaters, air conditioners, floor heating devices, and the like, heat exchangers for exchanging heat between two types of fluids (for example, water and refrigerant) are used.

  For example, Patent Document 1 describes a heat exchanger including a housing having a rectangular flow path and a heat transfer tube disposed in a flow path inside the housing.

Patent Document 2 describes a heat exchanger including a water pipe and a refrigerant pipe having different inner diameters. In this heat exchanger, the water pipe and the refrigerant pipe are formed into a track shape in contact with each other.
JP 2005-24109 A JP 2006-162204 A

  In the heat exchanger described in Patent Document 1, it is necessary that the heat transfer tube through which the refrigerant flows has a double structure (so-called detection tube structure) so that water and the refrigerant are not mixed even if the refrigerant tube is damaged. . For this reason, there is a problem that it is difficult to achieve weight reduction (resource saving).

  The heat exchanger described in Patent Document 2 is advantageous in terms of weight reduction because it does not need to employ a detector tube structure. However, in response to the recent global warming problem, even higher efficiency is required for this type of heat exchanger.

  Therefore, an object of the present invention is to provide a heat exchanger that is lightweight and highly efficient.

That is, the present invention
A plurality of first heat transfer tubes through which the first fluid flows;
A plurality of second heat transfer tubes through which a second fluid to exchange heat with the first fluid flows;
The first heat transfer tube has a vortex shape with one end positioned on the vortex center side and the other end on the outer periphery side of the vortex,
When the direction from the center side of the vortex toward the outer peripheral side is defined as a horizontal direction, and any two portions of the first heat transfer tube adjacent to each other in the horizontal direction are defined as an inner portion and an outer portion, the first portion at the inner portion is The distance in the horizontal direction between the center of the first heat transfer tube and the center of the first heat transfer tube at the outer portion is equal to or greater than the outer diameter of the first heat transfer tube;
The second heat transfer tube has a vortex shape corresponding to the first heat transfer tube so that the locus of the center of the first heat transfer tube and the locus of the center of the second heat transfer tube have a translational symmetry. And
Provided is a heat exchanger in which the first heat transfer tubes and the second heat transfer tubes are alternately stacked so as to contact each other along the longitudinal direction of each heat transfer tube.

  In the present invention, the first heat transfer tube has a vortex shape. Similar to the first heat transfer tube, the second heat transfer tube also has a vortex shape. The shape of the vortex of the second heat transfer tube corresponds to the shape of the vortex of the first heat transfer tube. The first heat transfer tubes and the second heat transfer tubes are alternately stacked, whereby the first heat transfer tubes and the second heat transfer tubes are in contact with each other along the longitudinal direction. Except for the uppermost heat transfer tube and the lowermost heat transfer tube, one heat transfer tube is sandwiched by another set of heat transfer tubes. With such a configuration, a sufficient contact area between the first heat transfer tube and the second heat transfer tube is ensured, so that excellent heat exchange efficiency can be expected. Moreover, according to the heat exchanger of this invention, since the fluid which flows through a 1st heat exchanger tube does not contact a 2nd heat exchanger tube directly, it is not necessary to employ | adopt a detector tube structure.

  Moreover, regarding the first heat transfer tube, the distance in the horizontal direction between the center at the inner portion and the center at the outer portion is equal to or greater than the outer diameter of the first heat transfer tube. That is, the inner part and the outer part are separated in the horizontal direction. Therefore, the spiral first heat transfer tubes and the second spiral heat transfer tubes can be alternately stacked, and the height of the entire heat exchanger can be easily limited. In addition, stacking work becomes easy, which is advantageous in reducing production costs.

  FIG. 1 is a plan view of a heat exchanger according to an embodiment of the present invention. FIG. 2 is a II-II cross-sectional view of the heat exchanger shown in FIG. As shown in FIGS. 1 and 2, the heat exchanger 100 of the present embodiment includes a plurality of first heat transfer tubes 13, a plurality of second heat transfer tubes 14, and a connector for bundling the end portions of the same type of heat transfer tubes. 15.

  The first fluid circulates inside the first heat transfer tube 13, and the second fluid circulates inside the second heat transfer tube 14. Thereby, heat exchange is performed between the first fluid and the second fluid. Specific examples of the first fluid are refrigerants such as carbon dioxide and hydrofluorocarbon, and specific examples of the second fluid are water. A specific application of the heat exchanger 100 is, for example, a heat pump type water heater 200 (see FIG. 11). However, the kind of each fluid and the use of the heat exchanger 100 are not limited to these.

As shown in FIG. 1, the first heat transfer tube 13 has a vortex shape. One end 13a of the first heat transfer tube 13 is located on the center side of the vortex, and the other end 13b of the first heat transfer tube 13 is located on the outer periphery side of the vortex. As shown in FIG. 2, arbitrary two portions of the first heat transfer tubes 13 adjacent to each other in the horizontal direction WL are defined as an inner portion 13 j and an outer portion 13 k. At this time, the distance W _{1 in} the horizontal direction WL between the center C ₁ of the first heat transfer tube 13 at the inner portion 13j and the center C ₁ of the first heat transfer tube 13 at the outer portion 13k is the outside of the first heat transfer tube. larger than the diameter D _1. In other words, the inner portion 13j and the outer portion 13k are separated from each other in the horizontal direction WL. A gap AG is formed between the inner portion 13j and the outer portion 13k.

  In this specification, the direction from the center side of the vortex toward the outer peripheral side is defined as the horizontal direction WL, and the direction perpendicular to the horizontal direction WL is defined as the vertical direction HL (see FIG. 2). 2 shows a cross section parallel to both the horizontal direction WL and the vertical direction HL.

As shown in FIGS. 1 and 2, like the first heat transfer tube 13, the second heat transfer tube 14 also has a vortex shape. One end 14b of the second heat transfer tube 14 is located on the vortex center side, and the other end 14a of the second heat transfer tube 14 is located on the outer periphery side of the vortex. The shape of the vortex of the second heat transfer tube 14 is the same as the shape of the vortex of the first heat transfer tube 13. Specifically, the locus of the center C ₁ of the first heat transfer tube 13 and the locus of the center C ₂ of the second heat transfer tube 14 are in a translational symmetry relationship. “Translational symmetry” refers to a relationship that can be superimposed by translation. In the present embodiment, when the locus of the center C ₂ of the second heat transfer tube 14 is translated in the vertical direction HL, the locus of the center C ₁ of the first heat transfer tube 13 overlaps.

  That is, the heat exchanger 100 is configured by alternately stacking the first heat transfer tubes 13 and the second heat transfer tubes 14. The first heat transfer tube 13 and the second heat transfer tube 14 are in contact with each other along the longitudinal direction, and are bonded to each other using a bonding material such as a brazing material or solder. Except for the first heat transfer tube 13 located at the top and the first heat transfer tube 13 located at the bottom, one heat transfer tube is sandwiched between another set of heat transfer tubes. Thereby, a sufficiently large heat transfer area can be ensured. Further, when one heat transfer tube is sandwiched by another set of heat transfer tubes, the temperature distribution of the sandwiched heat transfer tube itself becomes uniform.

  The ease of heat transfer is inversely proportional to the distance from the heat source. Therefore, when the water pipe (for example, the second heat transfer pipe 14) and the refrigerant pipe (for example, the first heat transfer pipe 13) are in contact only on one side, the heat of the refrigerant pipe becomes difficult to move to the opposite side of the water pipe, and the heat exchange amount Becomes smaller. On the other hand, when the water pipe is sandwiched between the refrigerant pipes, efficient heat transfer occurs on both the upper and lower sides of the water pipe, so that the heat exchange amount can be increased.

  In the present embodiment, the number of first heat transfer tubes 13 is four, and the number of second heat transfer tubes 14 is three. In other words, the total number of heat transfer tubes stacked is an odd number. Since the number of the second heat transfer tubes 14 is smaller than that of the first heat transfer tubes 13, all the second heat transfer tubes 14 are sandwiched between the sets of the first heat transfer tubes 13. If the configuration is such that the water to be heated flows through the second heat transfer tube 14, all the water tubes (second heat transfer tubes 14) are sandwiched between the refrigerant tubes (first heat transfer tubes 13) from above and below, and the amount of heat exchange is increased. it can. However, the number of the first heat transfer tubes 13 and the number of the second heat transfer tubes 14 may be equal.

  In a general heat exchanger, a desired heat exchange capability is provided by adjusting the length of the heat transfer tube and the diameter of the heat transfer tube. In addition to this, according to the heat exchanger 100 of the present embodiment, the heat exchange capacity can be adjusted also by increasing or decreasing the number of heat transfer tubes, so it is easy to provide a wide range of specifications.

  As shown in FIG. 2, the outer diameter of the first heat transfer tube 13 and the outer diameter of the second heat transfer tube 14 may be equal to each other. The outer diameter of the heat transfer tube 14 may be different. In the modification shown in FIG. 3, the outer diameter of the first heat transfer tube 13 is smaller than the outer diameter of the second heat transfer tube 14. Usually, since the type of fluid flowing through the first heat transfer tube 13 and the type of fluid flowing through the second heat transfer tube 14 are different, the outer diameters of the heat transfer tubes are also different.

  Further, in the present embodiment, the first heat transfer tube 13 and the second heat exchanger 100 are shaped so that the heat exchanger 100 has a rectangular frame shape in plan view, specifically, a rectangular frame shape having four round corners. The shape of the vortex of the heat transfer tube 14 is determined. In addition, all the bent portions of the first heat transfer tube 13 and the second heat transfer tube 14 as the portions constituting the four corner portions of the heat exchanger 100 have a predetermined bending radius R. Therefore, in the four corner portions, the gap AG is wider than the portion other than the corner portions.

  For example, the bending radius of the heat transfer tube of the heat exchanger described in Patent Document 2 described above changes stepwise. Therefore, there is a high possibility that the process of bending the heat transfer tube becomes complicated. Specifically, there is a possibility that the number of molds corresponding to the number of windings of the heat transfer tube is prepared, and it is necessary to perform hot bending of the heat transfer tube and replacement of the mold alternately. On the other hand, according to the heat exchanger 100 of this embodiment, since the 1st heat exchanger tube 13 and the 2nd heat exchanger tube 14 should just be bent with the predetermined | prescribed bending radius R, the process of bending a heat exchanger tube is easy. .

The bending radius R is preferably adjusted so as to satisfy the relationship of 3.5D ₁ >R> 2.5D ₁ (where D ₁ = the outer diameter of the first heat transfer tube). Each heat transfer tube is bent under conditions of a bending radius R and a bending angle of 90 °.

  As shown in FIGS. 1 and 2, a spacer 12 is disposed between the inner portion 13j and the outer portion 13k. The spacer 12 forms an air gap AG between the inner portion 13j and the outer portion 13k. The spacer 12 and the gap AG are not essential, and when the heat exchange between the inner portion 13j and the outer portion 13k is so small as not to affect the heat exchange efficiency, the inner portion 13j and the outer portion 13k. And may be in contact with each other. However, the presence of the gap AG, that is, the fact that the inner portion 13j and the outer portion 13k are not in direct contact brings about the following effects.

  For example, when paying attention to the first heat transfer tube 13, there is always a temperature difference between the fluid flowing through the inner portion 13j and the fluid flowing through the outer portion 13k. Therefore, when the inner part 13j and the outer part 13k are in contact, heat exchange occurs between the inner part 13j and the outer part 13k. Then, heat exchange that should occur between the fluid flowing through the first heat transfer tube 13 and the fluid flowing through the second heat transfer tube 14 is hindered, and as a result, the heat exchange efficiency may be reduced. On the other hand, when the inner portion 13j and the outer portion 13k are separated by the air gap AG, heat exchange hardly occurs between the inner portion 13j and the outer portion 13k.

  Further, in the present embodiment, all the first heat transfer tubes 13 and the second heat transfer tubes 14 are arranged in a line in the vertical direction HL. The first heat transfer tube 13 and the second heat transfer tube 14 are in direct contact only with portions belonging to the same row. That is, as shown in FIG. 2, the portion 13j of the first heat transfer tube 13 is in direct contact with only the portion 14j of the second heat transfer tube 14 belonging to the same row as this, and the portion 14k on the outer circumference or the portion 14j on the inner circumference. The portion 14 i is separated from the gap AG and / or the spacer 12. The temperature of the 2nd fluid (for example, water) which distribute | circulates the 2nd heat exchanger tube 14 is each different in each part 14i, 14j, 14k. Therefore, when only the portions 13j and 14j belonging to the same row are in contact with each other, more efficient heat exchange can be performed than in contact with a plurality of portions having different temperatures.

“All the first heat transfer tubes 13 and the second heat transfer tubes 14 are arranged in a line in the vertical direction HL” means that the position of the center C ₁ of the first heat transfer tube 13 and the second heat transfer tube 14 This means that the position with the center C ₂ coincides with the horizontal direction WL. However, this does not necessarily mean complete matching, and assembly tolerances and minute deviations are allowed as long as the above-described effects are obtained.

  In general, the heat transfer tubes 13 and 14 are made of a metal having high thermal conductivity such as copper or aluminum. The spacer 12 only needs to be made of a material having a lower thermal conductivity than such a metal. Specifically, examples of the material of the spacer 12 include metals, resins, glasses, and ceramics having low thermal conductivity such as stainless steel. The spacer 12 extends in the vertical direction HL so as to straddle the uppermost heat transfer tube and the lowermost heat transfer tube. Although the dimension of the spacer 12 regarding the longitudinal direction of a heat exchanger tube is not specifically limited, It is better not to be too large. This is to prevent heat exchange from occurring between the inner part and the outer part via the spacer 12.

  Note that each heat transfer tube can be bent so that the gap AG is formed without providing the spacer 12. However, by providing the spacer 12, the bending process is facilitated, and the contact between the inner portion and the outer portion can be reliably prevented with respect to each heat transfer tube.

  4 is a partial side view of the heat exchanger shown in FIG. 1, and shows a portion surrounded by a broken line SD in FIG. As shown in FIG. 4, the first heat transfer tube 13 and the second heat transfer tube 14 include a corrugated portion 19 having a predetermined amplitude P in the stacking direction of these heat transfer tubes (= vertical direction HL). In such a corrugated part 19, the fluid flowing through each heat transfer tube meanders in the vertical direction HL, so that a boundary layer is hardly formed, and heat exchange efficiency is improved.

The amplitude P of the waveform portion 19 is a value specified by the distance between the center of the heat transfer tube and the horizontal reference plane HF. The horizontal reference plane HF is a plane parallel to the horizontal direction WL, and is a plane that bisects an arbitrary first heat transfer tube 13 (for example, the first heat transfer tube 13 positioned at the top) in the vertical direction HL. The amplitude P can be adjusted so as to satisfy the relationship of 2.0D ₁ >P> 0.3D ₁ (where D ₁ = the outer diameter of the first heat transfer tube 13).

Further, the corrugated portion 19 may have a predetermined period K (for example, one period is a range of 10D ₁ >K> 3D ₁ ) with respect to the longitudinal direction of each heat transfer tube. In that case, in the area where the corrugated portion 19 is formed, the locus of the center of each heat transfer tube shows, for example, a sine curve. The corrugated portion 19 may be formed over the entire circumference of the heat exchanger 100 or may be formed only in a part of the area. As shown in FIG. 1, for example, the corrugated portion 19 may be formed only in the straight areas E ₁ and E ₂ excluding the four corner portions. The straight area E ₁ is an area corresponding to the long side portion of the heat exchanger 100. The straight line area E ₂ is an area corresponding to the short side portion of the heat exchanger 100. Further, the corrugated portion 19 may be formed only in _{one of} the straight section E ₁ and the straight section E ₂ .

  Moreover, in the cross section parallel to both the horizontal direction WL and the vertical direction HL (the cross section of FIG. 2 in this specification), the position of the inner portion 13j of the first heat transfer tube 13 and the outer portion 13k of the first heat transfer tube 13 The corrugated portion 19 is formed so that the position coincides with the vertical direction HL. That is, the inner part 13j and the outer part 13k are in phase. In the cross-sectional view shown in FIG. 2 (or FIG. 3), the first heat transfer tubes 13 and the second heat transfer tubes 14 show a grid-like arrangement. According to such a configuration, it is easy to make the heat exchanger 100 compact. Further, it is advantageous in that the corrugated portion 19 can be formed by press-molding the stacked first heat transfer tube 13 and second heat transfer tube 14. The die used for press molding is also simplified.

However, as shown in FIG. 6A, the corrugated portion 19 may be formed so that the inner portion 13j of the first heat transfer tube 13 and the outer portion 13k of the first heat transfer tube 13 are in opposite phases. That is, the corrugated portion 19 may be formed such that the first heat transfer tube 13 and the second heat transfer tube 14 have a staggered arrangement in a cross section parallel to both the horizontal direction WL and the vertical direction HL. The locus of the center C ₁₂ of the first heat transfer pipe 13 in the inner portion 13j, and a locus of the center C ₁₁ of the first heat transfer pipe 13 in the outer portion 13k, when viewed from the side of the heat exchanger 100, in FIG. 6B As shown, each trajectory exhibits sinusoidal curves that are opposite in phase. Similarly, shows the locus of the center C ₂₁ of the second heat transfer pipe 14 in the interior portion 14j, the locus of the center C ₂₂ of the second heat transfer pipe 14 in the outer portion 14k is, the sine curve of opposite phases. According to such a configuration, with respect to each heat transfer tube, the distance between the inner portion and the outer portion can be earned, so that heat exchange between the inner portion and the outer portion can be effectively suppressed.

  In addition, as shown in FIG. 5, the 1st heat exchanger tube 13 and the 2nd heat exchanger tube 14 do not have a corrugated part, but each heat exchanger tube 13 and 14 may have a flat plate shape. That is, the shape of each heat transfer tube may be determined so that the center locus of each heat transfer tube shows a vortex in the horizontal reference plane. According to this structure, since the process which makes a heat exchanger tube into a waveform is unnecessary, manufacture is easy.

  As shown in FIG. 7, the first heat transfer tube 13 has flat surfaces 13p and 13q as contact surfaces with the second heat transfer tube 14. Similarly, the second heat transfer tube 14 has flat surfaces 14p and 14q as contact surfaces with the first heat transfer tube 13. The flat surface 13q of the first heat transfer tube 13 and the flat surface 14p of the second heat transfer tube 14 are in contact with each other to form a bonding surface (heat transfer surface). According to such a structure, the area of the joint surface of the 1st heat exchanger tube 13 and the 2nd heat exchanger tube 14 becomes large, and heat exchange efficiency increases. Further, the presence of the flat surfaces 13p, 13q, 14p, and 14q makes it difficult for assembly tolerances to occur. Thereby, it becomes possible to make the 1st heat exchanger tube 13 and the 2nd heat exchanger tube 14 contact reliably. Only one of the first heat transfer tube 13 and the second heat transfer tube 14 may have a flat surface.

As shown in FIG. 7, the flat surface 13p and the flat surface 13q of the first heat transfer tube 13 are symmetrical with respect to the surface VF including the center C ₁ of the first heat transfer tube 13 and parallel to the vertical direction HL. . Similarly, with respect to the surface VF, the flat surface 14p and the flat surface 14q of the second heat transfer tube 14 are respectively left-right symmetric. The width W ₁ of the flat surface 13p and the flat surface 13q can be adjusted so as to satisfy the relationship of W ₁ > 0.05 × (the outer diameter D ₁ of the first heat transfer tube 13), for example. Similarly, the width W ₂ of the flat surface 14p and the flat surface 14q can be adjusted so as to satisfy the relationship of W ₂ > 0.05 × (the outer diameter D ₂ of the second heat transfer tube 14), for example.

  As shown in FIG. 7, the first heat transfer tube 13 and the second heat transfer tube 14 are joined together by a joining material such as a brazing material or solder. The bonding material 17 is interposed between the flat surface 13q of the first heat transfer tube 13 and the flat surface 14p of the second heat transfer tube 14 in the form of a thin layer, and spans the first heat transfer tube 13 and the second heat transfer tube 14. To form a fillet. The fillet not only improves the joint strength between the first heat transfer tube 13 and the second heat transfer tube 14, but also contributes to an improvement in heat exchange efficiency. In addition, the joining material 17 does not need to be arrange | positioned in the whole region regarding the longitudinal direction of the contact surface of the 1st heat exchanger tube 13 and the 2nd heat exchanger tube 14. FIG. For example, there may be a portion where the bonding material 17 is not disposed within a predetermined range from the spacer 12.

  As shown in FIG. 8, minute dimples 13 g (concave portions) may be formed on the surface of the first heat transfer tube 13. If dimples 13g exist on the joint surface between the first heat transfer tube 13 and the second heat transfer tube 14, the dimple 13g contributes to an increase in the area of the joint surface between the first heat transfer tube 13 and the second heat transfer tube 14. The heat exchange efficiency of the exchanger 100 is improved. Moreover, when the dimple 13g is formed, the wettability between the bonding material 17 and the first heat transfer tube 13 is improved. Furthermore, if the dimple 13g protrudes inside the first heat transfer tube 13, an effect of preventing the boundary layer from becoming thick inside the first heat transfer tube 13 can be obtained. Such a dimple 13g is preferably formed so that the depth of the dimple 13g is shallower than the thickness of the first heat transfer tube 13. Similar dimples 14 g may be formed on the surface of the second heat transfer tube 14. Instead of the dimples 13g and 14g, or together with the dimples 13g and 14g, convex portions may be formed.

  As shown in FIG. 1, one end 13 a and the other end 13 b of the four first heat transfer tubes 13 are bundled together by a connector 15. A fluid is sent to each of the first heat transfer tubes 13 via the connector 15. The fluid after flowing through the first heat transfer tube 13 joins at the downstream connector 15 to become one flow. Similarly, one end 14 a and the other end 14 b of the three second heat transfer tubes 14 are bundled together by a connector 15. Each connector 15 serves as a branch pipe that branches the fluid flow or a junction pipe that joins the fluid flow.

  When the heat exchanger 100 is used as a water-refrigerant heat exchanger, a high-temperature refrigerant is passed through the first heat transfer tube 13 and water is passed through the second heat transfer tube 14. For example, with respect to the first heat transfer tube 13, an end 13 a located on the center side of the vortex is used as a discharge port, and an end 13 b located on the outer periphery side of the vortex is used as an introduction port. Regarding the second heat transfer tube 14, an end portion 14a located on the outer peripheral side of the vortex is used as a discharge port, and an end portion 14b located on the center side of the vortex is used as an introduction port. In this way, the water flowing through the first heat transfer tube 13 and the refrigerant flowing through the second heat transfer tube 14 form a counter flow, which is advantageous in terms of heat exchange efficiency.

  Next, a method for manufacturing the heat exchanger 100 shown in FIG. 1 will be briefly described. In the present embodiment, the first heat transfer tube 13 and the second heat transfer tube 14 are each configured by a single heat transfer tube. However, the first heat transfer tube 13 and the second heat transfer tube 14 may each include a plurality of portions connected to each other by welding or a joint.

  As shown in FIG. 9 (S1), a plurality of straight first heat transfer tubes 13 and a plurality of straight second heat transfer tubes 14 are prepared. These heat transfer tubes 13 and 14 are arranged alternately and in parallel on the support base. The heat transfer tubes 13 and 14 are temporarily fixed by the spacer 12 so that they are in close contact with each other. A bonding material (see FIG. 7) is disposed at the contact portion between the first heat transfer tube 13 and the second heat transfer tube 14. When a wire-shaped member is used as the bonding material, it is easy to arrange the bonding material along the longitudinal direction of each heat transfer tube. Further, a sheet-like bonding material may be disposed between the first heat transfer tube 13 and the second heat transfer tube 14.

  Next, in order to melt the bonding material, the assembly 21 including the first heat transfer tube 13, the second heat transfer tube 14, and the spacer 12 is carried into a heat treatment furnace and heated. As a result, the first heat transfer tube 13 and the second heat transfer tube 14 are joined by the joining material and integrated.

  In addition, the joining material may be arrange | positioned in the whole area of the longitudinal direction of each heat exchanger tube, and there may be an area where the joining material is not arrange | positioned. For example, the area L between the spacer 12 and a position advanced from the spacer 12 toward one end of the heat transfer tube by a predetermined distance can be defined as an area where no bonding material is disposed. If there is a section L in which the bonding material is not arranged, it becomes possible to cause the section L to absorb distortion generated during thermal deformation and bending, and the dimensional accuracy of the heat exchanger 100 is improved. In addition, you may make it perform joining operation | movement with the spacer 12 and each heat exchanger tube separately.

  Next, the assembly 21 is bent sequentially from the end so as to have a vortex shape by using a mold for giving a predetermined bending radius R (see FIG. 1) to each heat transfer tube (S2). Further, the spiral assembly 21 is pressed with a mold for corrugating each heat transfer tube (S3). As a result, the waveform portion 19 described with reference to FIG. 4 is formed. Finally, the heat exchanger 100 is completed by connecting both ends of each heat transfer tube to the connector.

  At the same time when the corrugated portion 19 is formed by press working, the heat transfer tubes 13 and 14 are crushed in the vertical direction HL, and the flat surfaces 13p, 13q, 14p, and 14q described with reference to FIG. 7 can be formed. . By forming the flat surfaces 13p, 13q, 14p, and 14q, there is no problem even if the heat transfer tubes 13 and 14 are deformed somewhat horizontally (ellipse).

  Moreover, you may implement the press work for forming the waveform part 19 (FIG. 4) before the process of bending the 1st heat exchanger tube 13 and the 2nd heat exchanger tube 14 in a vortex. As shown in FIG. 10, first, first straight heat transfer tubes 13 and second heat transfer tubes 14 are prepared (ST1). Next, each of the first heat transfer tube 13 and the second heat transfer tube 14 is pressed into a wave shape (ST2). At this time, flat surfaces 13p, 13q, 14p, and 14q can be formed on each heat transfer tube. Next, the 1st heat exchanger tube 13 with which the waveform was attached and the 2nd heat exchanger tube 14 with the waveform similarly were arranged alternately. The heat transfer tubes 13 and 14 are temporarily fixed by the spacer 12 so that they are in close contact with each other. A bonding material is disposed at a contact portion between the first heat transfer tube 13 and the second heat transfer tube 14 (ST3).

  Next, in order to melt the bonding material, the assembly 23 including the first heat transfer tube 13, the second heat transfer tube 14, and the spacer 12 is carried into a heat treatment furnace and heated. As a result, the first heat transfer tube 13 and the second heat transfer tube 14 are joined by the joining material and integrated. Finally, the heat exchanger 100 is completed by bending the assembly 23 in a spiral shape (ST4).

  In addition, you may prepare the assembly 21 shown to step S1 of FIG. 9 using the heat exchanger tubes 13 and 14 in which the flat surfaces 13p, 13q, 14p, and 14q were formed previously by press work. Furthermore, firstly, a step of bending each heat transfer tube in a spiral shape is performed, then a step of imparting a waveform to each heat transfer tube is performed, and finally, a step of stacking and brazing each heat transfer tube is performed. It may be. Thus, even if the order of each process is changed, the same heat exchanger 100 can be manufactured.

  Next, a specific application of the heat exchanger 100 will be described. FIG. 11 is a configuration diagram of a heat pump type water heater as an application target of the heat exchanger 100.

  The heat pump hot water supply apparatus 200 includes a heat pump unit 201 and a tank unit 203. Hot water produced by the heat pump unit 201 is stored in the tank unit 203. Hot water is supplied from the tank unit 203 to the hot-water tap 204. The heat pump unit 201 includes a compressor 205 that compresses the refrigerant, a radiator 207 that radiates the refrigerant, an expansion valve 209 that expands the refrigerant, an evaporator 211 that evaporates the refrigerant, and a refrigerant pipe 213 that connects these devices in this order. I have. Instead of the expansion valve 209, a positive displacement expander that can recover the expansion energy of the refrigerant may be used. The heat exchanger 100 can be used as the radiator 207.

The perspective view of the heat exchanger concerning one Embodiment of this invention. II-II sectional view of the heat exchanger shown in FIG. Sectional drawing concerning the modification using the 1st heat exchanger tube and 2nd heat exchanger tube from which an outer diameter differs mutually Partial side view of the heat exchanger shown in FIG. Side view of a modification using straight heat transfer tubes Sectional drawing concerning the modification in which the inner part and outer part of a heat exchanger tube show a reverse phase Conceptual diagram showing the center trajectory of the heat transfer tube Enlarged sectional view of the first heat transfer tube and the second heat transfer tube Schematic showing the dimples formed on the surface of the heat transfer tube Process drawing of the manufacturing method of the heat exchanger shown in FIG. Process drawing of another manufacturing method of the heat exchanger shown in FIG. Configuration diagram of a heat pump type water heater including the heat exchanger shown in FIG.

Explanation of symbols

12 spacer 13 first heat transfer tube 14 second heat transfer tube 13p, 13q, 14p, 14q flat surface 13g, 14g dimple 13j, 14j inner portion 13k, 14k outer portion 19 corrugated portion 100 heat exchanger WL horizontal direction HL vertical direction AG gap

Claims (9)

A plurality of first heat transfer tubes through which the first fluid flows;
A plurality of second heat transfer tubes through which a second fluid to exchange heat with the first fluid flows;
The first heat transfer tube has a vortex shape having one end positioned on the vortex center side and the other end on the outer periphery side of the vortex,
When the direction from the center side of the vortex toward the outer peripheral side is defined as a horizontal direction, and any two portions of the first heat transfer tube adjacent to each other with respect to the horizontal direction are defined as an inner portion and an outer portion, the first portion at the inner portion is A distance in the horizontal direction between the center of the first heat transfer tube and the center of the first heat transfer tube at the outer portion is equal to or greater than the outer diameter of the first heat transfer tube;
The second heat transfer tube has a vortex shape corresponding to the first heat transfer tube so that the locus of the center of the first heat transfer tube and the locus of the center of the second heat transfer tube are in translational symmetry. And
The heat exchanger in which the first heat transfer tubes and the second heat transfer tubes are alternately stacked so as to contact each other along the longitudinal direction of each heat transfer tube. All the first heat transfer tubes and the second heat transfer tubes are arranged in a vertical direction orthogonal to the horizontal direction,
The heat exchanger according to claim 1, wherein the first heat transfer tube and the second heat transfer tube are in direct contact with each other only in portions belonging to the same row.   The heat exchanger according to claim 1 or 2, wherein the first heat transfer tube and the second heat transfer tube include a corrugated portion having a predetermined amplitude in a stacking direction of the heat transfer tubes.   4. The corrugated portion is formed so that a position of the inner portion and a position of the outer portion coincide with each other in the vertical direction in a cross section parallel to both the horizontal direction and the vertical direction. The described heat exchanger.   The number of the first heat transfer tubes and the number of the second heat transfer tubes are equal, or the number of the second heat transfer tubes is one less than the number of the first heat transfer tubes. The heat exchanger according to item. The outer diameter of the second heat transfer tube is equal to or greater than the outer diameter of the first heat transfer tube;
Further comprising a spacer disposed between the inner portion and the outer portion;
The heat exchanger according to any one of claims 1 to 5, wherein a gap is formed between the inner portion and the outer portion by the spacer.   The heat exchanger according to any one of claims 1 to 6, wherein the first heat transfer tube has a flat surface as a contact surface with the second heat transfer tube.   The heat exchanger according to any one of claims 1 to 7, wherein the second heat transfer tube has a flat surface as a contact surface with the first heat transfer tube. The vortex shapes of the first heat transfer tube and the second heat transfer tube are determined so that the heat exchanger has a rectangular frame shape in plan view,
All the bending parts of the said 1st heat exchanger tube as a part which comprises the four corner parts of the said heat exchanger, and a 2nd heat exchanger tube have predetermined | prescribed bending radius R, Any one of Claims 1-8. The heat exchanger according to item.

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