JP2011017475A - Heat exchanger for hot water supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance heat exchanging performance of a heat exchanger for hot water supply without making a design change of cross-sectional shape of the heat exchanger for hot water supply.SOLUTION: The heat exchanger for hot water supply includes a refrigerant passage through which a refrigerant for heating water by heat exchange between the refrigerant and water flows, and a water passage through which water heated by the refrigerant flows. Both of the refrigerant passage and water passage are formed of tubes. The water passage tube forming the water passage includes first circular arc parts 31a, 31b, 31c repeated by turns, and second circular arc parts 32a, 32b, 32c having reverse curvature to the first circular arc parts. When an end-to-end length between the end of the first circular arc part and the end of the second circular arc part is set to L (mm) and a radius of curvature of the first circular arc part and second circular arc part is set to R (mm), an expression (1): 0≤L/R≤1 is to be satisfied.

Description

  The present invention relates to a hot water supply heat exchanger that performs heat exchange between a refrigerant and water.

  2. Description of the Related Art Conventionally, as a heat exchanger for exchanging heat between a heat exchange medium (refrigerant) and a fluid such as water, a flow path for circulating a refrigerant and a flow path for a fluid heated by heat exchange such as water are provided. Various heat exchangers configured by combining two heat transfer tubes so as to exchange heat between water or the like and a refrigerant have been used.

  Conventionally, as a heat exchanger of a system for exchanging heat between refrigerant and water, as disclosed in Patent Documents 1 to 5, heat transfer tubes for circulating the refrigerant inside, and water for circulating inside Various proposals have been made in which a single heat exchanger is configured by combining the heat transfer tubes.

  For example, Patent Documents 1 and 2 disclose a double-pipe type hot water supply heat exchanger in which a refrigerant channel pipe is disposed in a water channel pipe, and Patent Documents 3 and 4 disclose a water channel pipe. There is disclosed a heat exchanger for hot water supply of a hot water supply type in which a refrigerant channel tube is wound around a refrigerant channel tube, and Patent Document 5 discloses a refrigerant channel tube as a water channel tube. A heat exchanger for hot water supply arranged so as to be embedded is disclosed.

  In such a heat exchanger for hot water supply, the entire heat exchanger is accommodated in a certain space, for example, by winding a long water channel tube in a spiral shape.

  For example, a conventional heat exchanger for hot water supply is wound in a rectangular spiral shape in Patent Document 1, wound in a spiral shape in Patent Document 2, and a core tube (straight portion and hairpin in Patent Document 3). Part) and U-shaped connecting pipes are alternately connected, and in Patent Document 4, it is spirally wound on a plane, and in Patent Document 5, it is spirally wound. These are intended to make the heat exchanger compact by making the winding method of the heat exchanger into such a shape.

JP 2006-170571 A (Claims, FIG. 1) Japanese Patent Laying-Open No. 2005-147466 (Claims, FIG. 3) JP 2003-28583 A (Claims, FIG. 9) JP 2007-218523 A (Claims, FIG. 1) Japanese Patent Laying-Open No. 2003-14382 (Claims, FIG. 3)

  In the above Patent Documents 1 to 5, in order to improve the heat exchange performance of the heat exchanger for hot water supply, studies are being made to improve the cross-sectional shape.

  However, since there is a limit to the improvement of the cross-sectional shape, and the change of the cross-sectional shape is a great design change in manufacturing, a new improvement means for improving the heat exchange performance is desired.

  Accordingly, an object of the present invention is to increase the heat exchange performance of the hot water supply heat exchanger and to increase the heat exchange performance per unit length without changing the cross-sectional shape of the hot water supply heat exchanger. is there.

  As a result of intensive studies to solve the problems in the prior art, the present inventors, as a result of alternately repeating the first circular arc portion and the first circular arc portion of the water flow channel tube forming the water flow channel, Water that circulates in the water flow channel pipe is configured by a second arc portion having an opposite curvature and the length between the end portions of the first arc portion and the second arc portion is shortened. When moving from the first arc portion to the second arc portion and when moving from the second arc portion to the first arc portion, the centrifugal force acting on the water in the cross section in the water channel pipe Since the direction is suddenly reversed from side to side, the effect of promoting turbulence of water in the water channel pipe can be enhanced, and this has found that heat transfer characteristics can be enhanced, leading to the completion of the present invention. It was.

That is, the present invention has a refrigerant channel through which a refrigerant for heating water by heat exchange between the refrigerant and water flows, and a water channel through which water heated by the refrigerant flows,
Both of the refrigerant channel and the water channel are formed by a tube,
The water flow path tube forming the water flow path includes a first arc portion that is alternately repeated, and a second arc portion having a curvature opposite to that of the first arc portion,
The length between the end portions of the first arc portion and the end portion of the second arc portion is L (mm), and the curvature radii of the first arc portion and the second arc portion are R (mm). When the following formula (1):
0 ≦ L / R ≦ 1 (1)
Meeting,
The heat exchanger for hot water supply characterized by these is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the heat exchange performance of the heat exchanger for hot water supply can be made high, and the heat exchange performance per unit length can be made high, without changing the cross-sectional shape of the heat exchanger for hot water supply.

It is a form example of the refrigerant | coolant flow path and water flow path which concern on the heat exchanger for hot water supply of this invention. It is a form example of the refrigerant | coolant flow path and water flow path which concern on the heat exchanger for hot water supply of this invention. It is a form example of the refrigerant | coolant flow path and water flow path which concern on the heat exchanger for hot water supply of this invention. It is a form example of the refrigerant | coolant flow path and water flow path which concern on the heat exchanger for hot water supply of this invention. It is a form example of the refrigerant | coolant flow path and water flow path which concern on the heat exchanger for hot water supply of this invention. It is a schematic diagram which shows the expansion | extension shape of the planar direction of the form example of the water flow-path pipe | tube which concerns on the heat exchanger for hot water supply of this invention. It is the figure which extracted one part of the 1st circular arc part and the 2nd circular arc part in FIG. It is a schematic diagram which shows the expansion | extension shape of the planar direction of the other form example of the water flow-path pipe | tube which concerns on the heat exchanger for hot water supply of this invention. It is a figure for demonstrating the length L between edge parts. It is a schematic diagram which shows a two-stage heat exchanger. It is a figure which shows the conventional heat exchanger for hot water supply. It is a figure which shows the shape of the heat exchange part of the comparative example 1.

The heat exchanger for hot water supply of the present invention has a refrigerant flow path through which a refrigerant for heating water by heat exchange between the refrigerant and water, and a water flow path through which water heated by the refrigerant flows,
Both of the refrigerant channel and the water channel are formed by a tube,
The water flow path tube forming the water flow path includes a first arc portion that is alternately repeated, and a second arc portion having a curvature opposite to that of the first arc portion,
The length between the end portions of the first arc portion and the end portion of the second arc portion is L (mm), and the curvature radii of the first arc portion and the second arc portion are R (mm). When the following formula (1):
0 ≦ L / R ≦ 1 (1)
It is a heat exchanger for hot water supply that satisfies

  The heat exchanger for hot water supply of the present invention has the refrigerant channel and the water channel. And in the hot water supply heat exchanger of this invention, heat exchange is performed between the refrigerant | coolant which flows through this refrigerant flow path, and the water which flows through this water flow path, and the water which flows through this water flow path is heated.

  In the heat exchanger for hot water supply of the present invention, the refrigerant channel and the water channel are formed by pipes, but the form is not particularly limited. Examples of the tubular body forming the refrigerant flow path (hereinafter also referred to as the refrigerant flow path pipe) and the tubular body forming the water flow path (hereinafter also referred to as the water flow path pipe) will be described below.

  For example, as shown in FIG. 1, the refrigerant channel and the pipe forming the water channel include a water channel tube 2 and a refrigerant channel tube 1 inserted into the water channel tube 2. And a double tube consisting of In the embodiment shown in FIG. 1, the inner side 3 of the refrigerant channel tube 1 serves as the refrigerant channel, and the gap 4 between the refrigerant channel tube 1 and the water channel tube 2 serves as the water channel. FIG. 1 is a schematic cross-sectional view of the pipe forming the refrigerant flow path and the water flow path taken along a plane perpendicular to the direction in which the water flow path is formed.

  In addition, as an example of the pipe forming the refrigerant flow path and the water flow path, as shown in FIG. 2, a water flow path pipe 6 and two refrigerants inserted into the water flow path pipe 6 are used. A double pipe comprising the flow path pipe 7 is mentioned. In the embodiment shown in FIG. 2, a gap 8 between the water flow channel pipe 6 and the refrigerant flow channel pipe 7 becomes the water flow channel, and an inner side 9 of the refrigerant flow channel tube 7 becomes the refrigerant flow channel. FIG. 2 is a schematic cross-sectional view of the pipe forming the refrigerant flow path and the water flow path taken along a plane perpendicular to the direction in which the water flow path is formed. Further, the two or more refrigerant flow pipes may be spirally twisted.

  In addition, as an example of the tubular body forming the refrigerant flow path and the water flow path, as shown in FIG. 3, the water flow path pipe 11 is wound around the water flow path pipe 11 in a spiral shape. The shape which consists of the refrigerant | coolant flow-path pipe | tube 12 is mentioned. In the embodiment shown in FIG. 3, the inner side 13 of the water flow channel tube 11 is the water flow channel, and the inner side 14 of the refrigerant flow channel tube 12 is the refrigerant flow channel. FIG. 3 is a schematic cross-sectional view of the pipe forming the refrigerant flow path and the water flow path taken along a plane parallel to the direction in which the water flow path is formed. The refrigerant flow path 12 is spirally wound around the water flow path pipe 11 in the order of 12 a, 12 b, 12 c, 12 d, 12 e, and 12 f, and is installed in contact with the water flow path pipe 11.

  Further, as an example of the tubular body forming the refrigerant flow path and the water flow path, as shown in FIG. 4, the water flow path pipe 16 and the water flow path pipe 16 are spirally wound around the water flow path pipe 16. The shape which consists of the refrigerant | coolant flow path pipe | tube 17 is mentioned. In the embodiment shown in FIG. 4, the inner side of the water flow channel pipe 16 is the water flow channel, and the inner side of the refrigerant flow channel tube 17 is the refrigerant flow channel. FIG. 4 is a schematic perspective view in which a part of a pipe forming the refrigerant flow path and the water flow path is cut out. In FIG. 4, three refrigerant flow path pipes 17a, 17b and 17c are shown. The refrigerant channel pipe is spirally wound and arranged so as to be embedded in the outer wall side groove 18 a formed by the spiral convex portion 18 b provided on the outer wall of the water channel pipe 16.

  In addition, as an example of the tubular body forming the refrigerant flow path and the water flow path, as shown in FIG. 5, the water flow path pipe 21 and the water flow path pipe 21 are installed so as to be recessed from the outside. The shape which consists of the refrigerant | coolant flow-path pipe | tube 22 is mentioned. In the embodiment shown in FIG. 5, the inner side 23 of the water flow channel tube 21 is the water flow channel, and the inner side 24 of the refrigerant flow channel tube 22 is the refrigerant flow channel. FIG. 5 is a schematic cross-sectional view of the pipe forming the refrigerant flow path and the water flow path taken along a plane perpendicular to the direction in which the water flow path is formed.

  In the heat exchanger for hot water supply of the present invention, the elongated shape in the plane direction of the water channel tube is a specific shape. Below, the expansion | extension shape of the planar direction of this water flow path pipe is shown. The extension shape in the planar direction of the water flow channel tube shown below indicates the extension shape of the water flow channel tube 2 in the embodiment shown in FIG. 1, and in the heat exchanger, the extension shape in the planar direction shown below. The coolant channel tube 1 is disposed in the water channel tube 2. Further, the extension shape in the planar direction of the water channel pipe shown below shows the extension shape in the plane direction of the water channel pipe 6 in the embodiment shown in FIG. The coolant channel tube 7 is disposed in the water channel tube 6 that is elongated in the plane direction. Further, the extension shape in the planar direction of the water channel pipe shown below indicates the extension shape in the plane direction of the water channel pipe 11 in the embodiment shown in FIG. 3. The refrigerant channel tube 12 is disposed around the water channel tube 11 having an elongated shape in the planar direction. Further, the extension shape in the planar direction of the water channel pipe shown below shows the extension shape in the plane direction of the water channel pipe 16 in the embodiment shown in FIG. The refrigerant flow channel pipe 17 is disposed around the water flow path pipe 16 that is elongated in the planar direction. Further, the extension shape in the planar direction of the water channel pipe shown below shows the extension shape in the planar direction of the water channel pipe 21 in the embodiment shown in FIG. The refrigerant channel tube 22 is arranged so as to be embedded in the water channel tube 21 having an elongated shape in the planar direction.

  With reference to FIGS. 6 to 9, the planar shape of the water channel pipe according to the heat exchanger for hot water supply of the present invention will be described. FIG. 6 is a schematic diagram showing an elongated shape in a planar direction of a configuration example of a water channel pipe according to the heat exchanger for hot water supply of the present invention, and FIG. 7 is a first arc portion and a second arc portion in FIG. FIG. 8 is a schematic view showing an elongated shape in the plane direction of another embodiment of the water channel pipe according to the heat exchanger for hot water supply of the present invention, and FIG. It is a figure for demonstrating the length between edge parts. In addition, in FIGS. 6-9, only this water flow path pipe | tube which concerns on the heat exchanger for hot water heaters of this invention is shown, and description of this refrigerant flow path pipe | tube which concerns on the heat exchanger for hot water heaters of this invention was abbreviate | omitted.

  In FIG. 6, the water channel tube 30 includes a first arc portion 31 and a second arc portion 32. Then, as shown in FIG. 6, the first arc portion 31a, the second arc portion 32a, the first arc portion 31b, the second arc portion 32b, the first arc portion 31c, and the second arc portion 32c in this order. The first arc portion 31 and the second arc portion 32 are alternately repeated. The inflection point 33a to the inflection point 33b is the first arc portion 31a, and the inflection point 33b to the inflection point 33c is the second arc portion 32a. The first arc part 31b is the point up to the inflection point 33d, the second arc part 32b is from the inflection point 33d to the inflection point 33e, and the inflection point 33f to the inflection point 33f is the first arc part 31b. One arc portion 31c is the second arc portion 32c from the inflection point 33f to the inflection point 33g. In the water channel pipe 30 shown in FIG. 6, the first arc portion 31 and the second arc portion 32 are directly connected at the inflection point 33.

  In the water channel tube 30, the water 35 flows from one end 34 a of the water channel tube 30 toward the other end 34 b of the water channel tube 30.

  FIG. 7 shows a diagram in which the first arc portion 31a and the second arc portion 32a in FIG. 6, that is, a portion from the inflection point 33a to the inflection point 33c are extracted. The first arc portion 31a and the second arc portion 32a have opposite curvatures. In the present invention, the fact that the curvature of the arc is reversed will be described with reference to FIGS. 6 and 7. When the curvature of the arc is reversed, the position of the center of curvature of the arc is the water channel pipe. The relationship which is right and left opposite to the advancing direction of 30 water flow paths is said. That is, when water flows through the water flow path pipe 30, the relationship between the arc in which the direction of water flow curves to the right and the arc that curves to the left is said to be that the curvature of the arc is reversed. For example, in FIG. 7, the center of curvature of the first arc portion 31 a is the position indicated by reference numeral 36 a and is on the right side of the water flow direction 37. On the other hand, the center of curvature of the second arc portion 32a is the position indicated by reference numeral 36b and is on the left side of the water flow direction 37.

  In FIG. 7, the central angle (°) of the first arc portion 31a and the central angle (°) of the second arc portion 32a are indicated by θ. The central angle θ of the first arc portion 31a is equal to one end of the first arc portion 31a (the starting point of the first arc portion 31), that is, the inflection point 33a and the center of curvature 36a of the first arc portion 31a. And the other end of the first arc portion 31a (the end point of the first arc portion 31), that is, the angle formed by the inflection point 33b. Similarly, the central angle θ of the second arc portion 32a is equal to one end of the second arc portion 32a (the start point of the second arc portion 32), that is, the inflection point 33b and the second arc portion 32a. This is the angle formed by the center of curvature 36b and the other end of the second arc portion 32a (the end point of the second arc portion 32), that is, the inflection point 33c.

  In FIG. 7, the radius of curvature (mm) of the first arc portion 31a and the radius of curvature (mm) of the second arc portion 32a are denoted by R. The radius of curvature R of the first arc portion 31a is the distance between the center line of the water channel pipe of the first arc portion 31a and the center of curvature 36a of the first arc portion 31a. The center line of the water flow channel pipe is the water flow channel tube of the embodiment shown in FIGS. 1 to 5, and the center of the water flow channel tube in the cross section perpendicular to the water flow direction is the water flow direction. It is a connected line. The same applies to the radius of curvature of the second arc portion 32a.

  In FIG. 8, the example in case (theta) of the 1st circular arc part and the 2nd circular arc part in this water channel pipe is 180 degrees is shown.

  In the embodiment shown in FIGS. 6 and 7, the first arc portion 31 and the second arc portion 32 are directly connected at the inflection point 33. The distance from the end of the second arc part 32 (the distance between the start point of the first arc part 31 and the end point of the second arc part 32 and the end point of the first arc part 31 and the second arc part 32 The distance from the start point) is 0 (mm).

  Further, in the water flow channel pipe according to the heat exchanger for hot water supply of the present invention, the first arc portion 31 and the second arc portion 32 may not be directly connected, as in the embodiment shown in FIG. And may be connected via a straight line portion (connecting portion).

  The length L between ends will be described with reference to FIG. The distance between the end of the first arc portion and the end of the second arc portion (the distance between the start point of the first arc portion and the end point of the second arc portion, and the end point of the first arc portion and the end of the first arc portion The distance from the starting point of the two arc portions) is the length L (mm) between the end portions of the first arc portion and the second arc portion. FIG. 9 is a diagram for explaining the length between the end portions. In FIG. 9, the first arc portion 41 and the second arc portion 42 are connected to both ends of a straight portion (connecting portion) 45. That is, one end of the first arc portion 41 (the end point of the first arc portion) and one end of the straight portion (connecting portion) 45 are connected by the connection point 44, and The end and one end of the second arc portion 42 (start point of the second arc portion) are connected by a connection point 46. The other end of the first arc portion 41 is connected to another straight portion (connecting portion), and the other end of the second arc portion 42 is connected to another straight portion (connecting portion). Yes. An end-to-end length L between the end of the first arc portion and the end of the second arc portion is the length of the straight portion (connecting portion) 45.

  Since the curvatures of the first arc portion and the second arc portion are opposite, when water flows through the water channel tube, the water flows in the water channel tube in the cross section of the water channel tube. The direction of the centrifugal force is reversed between the first arc portion and the second arc portion. And in the heat exchanger for hot water supply of this invention, the water which distribute | circulates this water flow pipe is shortened by shortening the length between the edge part of the edge part of this 1st circular arc part and the edge part of the 2nd circular arc part. When moving from the first arc portion to the second arc portion and when moving from the second arc portion to the first arc portion, the direction of the centrifugal force applied to the water flowing in the water channel pipe is determined. , Suddenly flip left and right. As a result, the region where the velocity boundary layer and the thin region of the temperature boundary layer in the cross section of the flow path are abruptly reversed left and right, so that a high turbulence promoting effect can be obtained, so that the heat transfer characteristics are high. Become.

And in the heat exchanger for hot water supply of this invention, the length between the edge part of the edge part of this 1st circular arc part and the edge part of this 2nd circular arc part is set to L, this 1st circular arc part and this 2nd circular arc The radius of curvature of the part is the following formula (1):
0 ≦ L / R ≦ 1 (1)
Meet. And it is preferable that it is 0 <= L / R <= 0.5.

  More preferably, the first arc portion and the second arc portion are directly connected. When the first arc portion and the second arc portion are directly connected, the length L between the end portions is 0 mm. That is, the value of L / R is more preferably 0.

In the heat exchanger for hot water supply of the present invention, when the outer diameter of the water channel pipe is D (mm), the following formula (2):
1 ≦ R / D ≦ 10 (2)
Is preferably satisfied, and 2 ≦ R / D ≦ 7 is particularly preferable. When the value of R / D is within the above range, the effect of promoting turbulence is enhanced. On the other hand, if the R / D value exceeds the above range, the effect of promoting turbulence tends to be low, and if it is less than the above range, failures such as buckling of the heat transfer tube are likely to occur, resulting in a decrease in reliability. It becomes easy to invite. The outer diameter D of the water channel pipe is an outer diameter of a cross section when the water channel pipe is cut along a plane perpendicular to the water flow direction.

  θ is preferably 60 to 290 °, particularly preferably 180 to 290 °. When θ is in the above range, the effect of promoting turbulence is enhanced.

  A total extension of the first arc portion and the second arc portion (when the connecting portion is between the first arc portion and the second arc portion, the first arc portion, the second arc portion, and The total extension of the connecting part) preferably occupies 70% or more of the length of the water flow path pipe of the heat exchange part, and particularly preferably 90% or more. When the total extension of the first arc portion and the second arc portion occupying the length of the water flow path pipe of the heat exchange portion is within the above range, the heat exchange performance is improved. In addition, this heat exchange part refers to the part in which heat exchange is performed between the refrigerant | coolant which distribute | circulates this refrigerant flow path, and the water which distribute | circulates this water flow path. The length of the water flow path pipe of the heat exchange section is, for example, the portion of the water flow path pipe in the double pipe of the refrigerant path pipe 1 and the water flow path pipe 2 in the embodiment shown in FIG. Refers to the length. Further, in the embodiment shown in FIG. 2, the length of the water flow path pipe in a portion that is a double pipe of the water flow path pipe 6 and the refrigerant flow path pipe 7 is indicated. Further, in the embodiment shown in FIG. 3, the length of the water flow path pipe of the portion where the refrigerant flow path pipe 12 is wound around the water flow path pipe 11 is indicated. Further, in the embodiment shown in FIG. 4, it indicates the length of the water flow path pipe where the refrigerant flow path pipe 17 is wound around the water flow path pipe 16. Further, in the embodiment shown in FIG. 5, the length of the water flow path pipe in the portion where the refrigerant flow path pipe 22 is recessed into the water flow path pipe 23 is indicated.

  In FIG. 6, although the 1st circular arc part and this 2nd circular arc part showed the example repeated in one plane, the heat exchanger for water heaters of this invention is not limited to this, The first arc portion and the second arc portion may be repeated on two or more planes. FIG. 10 is a schematic diagram showing the shape of a water flow path pipe according to a two-stage heat exchanger. In FIG. 10, the second stage 52 in which the first arc part and the second arc part are repeated is arranged on the first stage 51 in which the first arc part and the second arc part are repeated. Thus, one end of the first-stage 51 water channel pipe and one end of the second-stage water channel pipe are connected by a joint 53. In FIG. 10, the first stage 51 is shown in black, the second stage 52 is shown in dark gray, and the joint 53 is shown in light gray. Further, FIG. 10 shows only the water channel pipe related to the heat exchanger for hot water heater of the present invention, and the description of the refrigerant channel pipe related to the heat exchanger for hot water heater of the present invention is omitted.

  Since the water channel pipe according to the heat exchanger for hot water supply of the present invention is usually obtained by processing a seamless pipe, the first arc part and the second arc part (if the connecting part is present, The first arc portion, the second arc portion and the connecting portion) are one continuous tube. Therefore, when the first arc portion and the second arc portion are repeated on one plane, the first arc portion and the second arc portion that are normally repeated on the one plane are continuous. It is formed of one seamless tube. In addition, when the first arc portion and the second arc portion are repeated in two or more planes, usually the first arc portion and the second arc portion that are repeated in each step, The first arc portion and the second arc portion are formed by one continuous seamless pipe over two or more stages.

  The refrigerant flowing through the refrigerant flow path is not particularly limited. It is also possible to use a refrigerant mainly composed of carbon dioxide as the refrigerant flowing through the refrigerant flow path. The refrigerant mainly composed of carbon dioxide is carbon dioxide alone or a carbon dioxide refrigerant containing 0 to 15% by mass of refrigerating machine oil.

  FIG. 11 shows a conventional heat exchanger for hot water supply. In FIG. 11, a heat exchanger 61 is a double tube 62 in which a water channel tube is inserted into a solvent channel tube and is wound in a rectangular spiral shape. In the heat exchanger 61, since the curved portion 63 between the straight portion 64 and the straight portion 64 is all on the same curvature side, the velocity boundary layer and the temperature boundary layer are only in one direction of the flow path cross section. Since there is a thin region, a sufficient turbulence promoting effect cannot be obtained.

  EXAMPLES Next, although an Example is given and this invention is demonstrated more concretely, this is only an illustration and does not restrict | limit this invention.

(Example 1 and Comparative Example 1)
<Production of Heat Exchanger of Example 1>
The shape of the water channel tube was changed to the shape of the water channel tube shown in FIG. 6, and the heat exchanger of FIG. 3 was produced with the following dimensions.
・ Water channel tube: Outer diameter (D) = 9.5 mm, Wall thickness = 0.7 mm, Material is phosphorous deoxidized copper ・ Refrigerant channel tube: Outer diameter = 4 mm, Wall thickness = 0.5 mm, Material is phosphorus-removed Curvature radius R of the first arc part and second arc part of acid copper / water flow pipe R = 64mm
・ Center angle θ = 290 ° of the first arc portion and the second arc portion of the water channel pipe
・ The number of first arc portions of the water channel pipe = 3, the number of second arc portions of the water channel tube = 3, and the length L between the ends of the water channel tube = 0 mm.
・ R / D = 6.7, L / R = 0
・ Total length of heat exchange part = 2300mm
-Plane occupancy area S = 130,000 mm ^{2 of the} heat exchange part (plane occupancy width W1 = 520 mm of the heat exchange part, plane occupancy depth T1 = 250 mm of the heat exchange part)
In addition, W1 and T1 are the width | variety and depth of a heat exchange part also including the refrigerant | coolant flow path pipe wound helically around the water flow path pipe and the water flow path pipe.

<Production of Heat Exchanger of Comparative Example 1>
The shape of the water channel tube was as shown in FIG. 12, and the heat exchanger shown in FIG. 3 was produced with the following dimensions.
・ Water channel tube: outer diameter (D) = 16 mm, wall thickness = 0.7 mm, material is phosphorous deoxidized copper ・ Refrigerant channel tube: outer diameter = 4 mm, wall thickness = 0.5 mm, material is phosphorous deoxidized copper -Rectangular spiral, quadruple winding-Heat exchange part total length = 4500mm
-Plane occupancy area S of heat exchange part = 130,000 mm ² (Plane occupancy width W2 of heat exchange part = 520 mm, plane occupancy depth T2 = 250 mm of heat exchange part)
FIG. 12 shows the shape of the heat exchange part in which the water channel pipe and the refrigerant channel pipe spirally wound around the water channel pipe are integrated. In FIG. The description of the channel tube was omitted. W2 and T2 are the width and depth of the heat exchange section including the water flow path pipe and the refrigerant flow path pipe spirally wound around the water flow path pipe.

<Performance evaluation>
Evaluation Method Heat exchange performance was measured by circulating carbon dioxide refrigerant gas in the refrigerant channel tube and water in the water channel tube under the conditions shown in Table 1.

<Evaluation results>
When the heat exchange amount of Example 1 and Comparative Example 1 at a water flow rate of 1 L / min was compared, the heat exchange amount of Example 1 was the same as the heat exchange amount of the Comparative Example. When this is compared with the heat exchange amount per unit mass (per unit length) of the heat exchanger, the heat exchange amount per unit mass of the heat exchanger of Example 1 is 1.95 times that of Comparative Example 1. there were.

  ADVANTAGE OF THE INVENTION According to this invention, the heat exchanger for hot water supply which is excellent in heat exchange performance can be manufactured.

1, 7, 12, 17, 22 Refrigerant flow pipe 2, 6, 11, 16, 21, 30 Water flow pipe 31, 41 First arc portion 32, 42 Second arc portion 33 Inflection point 35 Water 36 Center of curvature 37 Water flow direction 45 Straight section (connecting section)
51 First stage 52 Second stage 61 Heat exchanger 62 Double pipe 63 Curved part 64 Straight line part θ Center angle R of arc part Curvature radius D of arc part Outer diameter of water channel pipe

Claims (4)

A coolant channel through which a coolant for heating water by heat exchange between the coolant and water flows, and a water channel through which water heated by the coolant flows,
Both of the refrigerant channel and the water channel are formed by a tube,
The water flow path tube forming the water flow path includes a first arc portion that is alternately repeated, and a second arc portion having a curvature opposite to that of the first arc portion,
The length between the end portions of the first arc portion and the end portion of the second arc portion is L (mm), and the curvature radii of the first arc portion and the second arc portion are R (mm). When the following formula (1):
0 ≦ L / R ≦ 1 (1)
Meeting,
A heat exchanger for hot water supply. When the outer diameter of the water channel pipe is D (mm), the following formula (2):
1 ≦ R / D ≦ 10 (2)
The hot water supply heat exchanger according to claim 1, wherein:   The total extension of said 1st circular arc part, said 2nd circular arc part, and a connection part occupies 70% or more of the length of the water flow-path pipe | tube of a heat exchange part, Either 1 or 2 characterized by the above-mentioned. Heat exchanger for hot water supply.   The heat exchanger for hot water supply according to any one of claims 1 to 3, wherein the refrigerant is a refrigerant mainly composed of carbon dioxide.