JP2011226763A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger that can prevent or suppress such a phenomenon that an rotational moment is produced between a heat transfer tube and a connecting member such as a header or the like connected therewith when a pressure within a spiral tube type heat transfer tube increases and improve the stability of fitting of heat transfer tubes or connecting members.SOLUTION: The heat exchanger HE1 includes a plurality of heat transfer tubes T1 and connecting members 2A and 2B that are fixed and connected therewith, wherein the plurality of heat transfer tubes T1 includes a plurality of straight tubes 1 extending in nearly same direction from the connection position with the connecting members 2A and 2B, and then spiral recesses 12 are formed on the inside surfaces of the plurality of straight tubes 1. First and second straight tubes 1L and 1R are provided as the plurality of straight tubes 1, and the spiral winding directions of the recesses 12 are different from each other in the first and second straight tubes 1L and 1R.

Description

  The present invention relates to a heat exchanger of a type in which water or other desired fluid is circulated in a heat transfer tube and the fluid is heated or cooled.

  As a heat transfer tube constituting the heat exchanger, there is a so-called spiral tube type in which spiral concave portions and convex portions are formed on the inner surface and the outer surface (see, for example, Patent Documents 1 and 2). According to such a heat transfer tube, in addition to an increase in the surface area (heat transfer area) of the outer surface and the inner surface of the heat transfer tube, the heat transfer medium acts as a fluid circulating in the heat transfer tube and a heat exchange medium acting on the outer surface of the heat transfer tube. A turbulent flow is produced, and the contact time between them and the heat transfer tube can be increased. Therefore, it is preferable for increasing the heat transfer efficiency. In the case where a plurality of such heat transfer tubes are used, the heat transfer tubes are connected to a header for inflow and outflow of fluid, as in other types of heat transfer tubes such as finned tubes.

  However, when the header is connected to the above-described spiral tube type heat transfer tube, the present inventor has found that the following problems occur.

  That is, in the fluid flow path communicating with the inside of the heat transfer tube, for example, when a water hammer occurs and the pressure in the heat transfer tube becomes considerably high, a twisting force (center extending in the longitudinal direction of the heat transfer tube) is applied to the heat transfer tube. Torque around the shaft) is generated. This phenomenon occurs because the concave portion formed on the inner surface of the heat transfer tube is spiral. The direction of the torsional force is opposite to the spiral winding direction of the recess, and is independent of the fluid flow direction in the heat transfer tube. When the header is fixedly connected to the heat transfer tube, the torsional force of the heat transfer tube may generate a rotating moment that rotates the header. In this case, the rotational moment acts as a reaction force that causes the header to rotate the heat transfer tube. Such force increases as the number of heat transfer tubes increases. The occurrence of the rotational moment described above between the header and the heat transfer tube causes unnecessary stress at the mounting location of the header and heat transfer tube, and the stability and reliability of the header and heat transfer tube mounting. From the viewpoint of increasing the thickness, it is not preferable.

Japanese Patent No. 4082058 JP-A-9-310991

  The present invention has been conceived under the circumstances as described above, and when the pressure in the so-called spiral tube type heat transfer tube becomes high, the heat transfer tube and the header connected to the heat transfer tube. Providing a heat exchanger that can appropriately prevent or suppress the phenomenon of rotational moments between connecting members such as heat exchangers and improve the stability and reliability of the installation of heat transfer tubes and connecting members. And that is the challenge.

  In order to solve the above problems, the present invention takes the following technical means.

The heat exchanger provided by the present invention includes a plurality of heat transfer tubes and a connection member fixedly connected to the plurality of heat transfer tubes, and the plurality of heat transfer tubes are connected to the connection member. A heat exchanger having a plurality of straight tubular body portions extending in substantially the same direction from a connection position, and having a spiral recess formed on the inner surface of the plurality of straight tubular body portions. The first and second straight tube portions are provided as the plurality of straight tube portions, and the first and second straight tube portions have a spiral winding direction of the recess. It is characterized by being different from each other.

  According to such a configuration, even if the pressure in the heat transfer tube is increased and a torsional force is generated in the plurality of straight tube portions, the heat transfer tube is generated in each of the first and second straight tube portions. The directions of torsional forces are opposite to each other. Therefore, the rotational moment generated by these torsional forces is canceled or reduced, so that a large rotational moment is not generated between the heat transfer tube and the connecting member. As a result, it is possible to avoid the occurrence of a large stress at the mounting position of the heat transfer tube and the connecting member due to the rotational moment, and it is possible to improve the mounting stability and reliability.

  In the present invention, preferably, as the plurality of heat transfer tubes, a heat transfer tube having the first straight tube portion and a heat transfer tube having the second straight tube portion are provided.

  According to such a configuration, the configuration of the heat exchanger intended by the present invention is obtained by combining the heat transfer tube having the first straight tube portion and the heat transfer tube having the second straight tube portion. It can be easily realized.

  In the present invention, preferably, the numbers of the first and second straight tube portions are substantially the same.

  According to such a configuration, it becomes easy to balance the magnitude of the torsional force generated in each of the first and second straight tube portions, and the rotational moment generated between the heat transfer tube and the connecting member. It is more preferable to reduce the size.

  In the present invention, preferably, the plurality of straight tube portions are arranged in one or a plurality of rows, and one of the first and second straight tube portions is provided in each row. They are lined up alternately.

  According to such a configuration, the first and second straight tube portions can be brought close to each other. For this reason, the rotational moment generated around the first straight tubular body portion is efficiently canceled or reduced by the rotational moment generated around the second straight tubular body portion. Therefore, it is more preferable to reduce the rotational moment generated between the heat transfer tube and the connecting member.

  In the present invention, preferably, all or a part of the plurality of heat transfer tubes have both the first and second straight tube portions, and the first and second straight tube portions. Are arranged in series in the longitudinal direction of the tube.

  According to such a configuration, the torsional force generated in the first straight tubular body portion of each heat transfer tube is offset or reduced by the torsional force generated in the second straight tubular body portion. It is possible to suppress a large torsional force from acting on the connecting member from each heat transfer tube. Therefore, it is more preferable in reducing the stress generated at the connecting portion between the heat transfer tube and the connecting member.

  In the present invention, preferably, a spiral convex portion is formed on the outer surface of each of the straight tubular body portions.

  Such a configuration is suitable for increasing the heat transfer area of each heat transfer tube and further improving the heat transfer efficiency.

  In the present invention, preferably, each of the heat transfer tubes further includes an additional straight tube portion connected to each of the straight tube portions via a curved tube portion. Helical concave portions and convex portions are also formed on the inner and outer surfaces of the straight tube portion.

  According to such a configuration, not only is the heat transfer area of the heat transfer tube expanded by providing the additional straight tube portion, but also the spiral shape formed in the additional straight tube portion. The heat transfer area can be further expanded by the presence of the concave and convex portions. Therefore, it is more suitable to obtain high heat exchange efficiency while reducing the total number of heat transfer tubes and suppressing the overall size.

  Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention with reference to the accompanying drawings.

(A) is a plane sectional view showing an example of the heat exchanger concerning the present invention, and (b) is an II section explanatory view of (a). (A) is a partially omitted front view showing an example of a heat transfer tube used in the heat exchanger shown in FIG. 1, and (b) is an enlarged view of a portion A in (a). (A)-(c) is sectional explanatory drawing which shows the other example of an arrangement | sequence of the 1st and 2nd straight pipe | tube part in the heat exchanger shown in FIG. (A) is a perspective view which shows the other example of the heat exchanger which concerns on this invention, (b) is IV-IV sectional explanatory drawing of (a). (A) is a perspective view which shows the other example of the heat exchanger which concerns on this invention, (b) is VV sectional explanatory drawing of (a). It is a perspective view which shows the other example of the heat exchanger which concerns on this invention. It is a perspective view which shows the other example of the heat exchanger which concerns on this invention. (A) is a plane sectional view showing other examples of the heat exchanger concerning the present invention, and (b) is a VIII-VIII sectional view of (a). It is a plane sectional view showing other examples of the heat exchanger concerning the present invention. FIG. 10 is a partially omitted front view showing an example of a heat transfer tube used in the heat exchanger shown in FIG. 9. It is a plane sectional view showing other examples of the heat exchanger concerning the present invention.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

1 and 2 show an example of a heat exchanger to which the present invention is applied.
The heat exchanger HE1 of the present embodiment is used as, for example, a component of a hot water supply device to perform hot water heating for hot water supply, and includes a plurality of heat transfer tubes T1, a pair of headers 2A and 2B, and these. The case 3 accommodated in the inside is provided. The heat exchanger HE1 is characterized by the configuration of the plurality of heat transfer tubes T1, and the overall basic structure of the other heat exchanger HE1 is the same as that conventionally known. Therefore, descriptions other than the configuration of the plurality of heat transfer tubes T1 are simple.

The case 3 has an inlet 30 and an outlet 31 for a heating medium that acts on each heat transfer tube T1. As the heating medium, for example, combustion gas generated by a combustion device (not shown) is used. The pair of headers 2A and 2B corresponds to an example of the “connecting member” in the present invention, and serves to support the heat transfer tubes T1 while allowing the hot water to flow into and out of the heat transfer tubes T1. Both end portions 10 of each heat transfer tube T1 are fixedly connected to the wall portions of the pair of headers 2A and 2B by means such as brazing or welding. Inside the header 2A, a water inlet chamber 20a connected to the water supply port 21 and a hot water discharge chamber 20b connected to the hot water outlet 22 are formed. Inside the header 2B, a hot water return chamber is formed. 20c is formed. When water is supplied from the water supply port 21 to the inlet chamber 20a, the water passes through the plurality of heat transfer tubes T1 near the inlet 30 and reaches the hot water return chamber 20c, and thereafter from the chamber 20c. It passes through the plurality of heat transfer tubes T1 near the discharge port 31 and flows into the hot water discharge chamber 20b. In such a process, the water is heated by the heating medium supplied into the case 3 to generate hot water, and this hot water is supplied from the hot water outlet 22 to a predetermined location.

  Each heat transfer tube T1 is made of a metal such as stainless steel or copper, and has a straight tube shape extending in a certain direction. That is, in the present embodiment, the entire heat transfer tube T1 is a straight tube portion 1. As clearly shown in FIG. 2, a spiral convex portion 11 is formed on the outer surface of the substantially full length region excluding both end portions 10 of the straight tubular body portion 1, and on the inner surface, A spiral recess 12 is formed. A spiral recess is formed between the projections 11, and a spiral projection is formed between the recesses 12. FIG. 2 shows an example in which the spiral convex portion 11 and the concave portion 12 are in the form of a multiple thread such as a four thread. If the convex part 11 and the recessed part 12 are made into the form of a multi-thread screw, it will become easy to provide the convex part 11 and the recessed part 12 closely. However, it is not limited to this, The convex part 11 and the recessed part 12 can also be made into the form of a single thread | thread.

  As the plurality of straight tube portions 1, two types of first and second straight tube portions 1 (1L, 1R) are provided. The first straight tube portion 1L has a spiral convex portion 11 and a concave portion 12 in the same winding direction as a left-hand screw (a screw that advances counterclockwise), and is shown in FIG. This is the case. On the other hand, in the second straight tubular body portion 1R, the spiral convex portion 11 and the concave portion 12 are wound in the same winding direction as a right-handed screw (a screw that advances clockwise). As the plurality of heat transfer tubes T1, there are two types, one having the first straight tube portion 1L and one having the second straight tube portion 1R. Note that, in FIG. 1, the spiral convex portion 11 is simply illustrated using a solid oblique line. The spiral concave portion 12 is formed on the back surface side of the convex portion 11. This is the same in the drawings of other embodiments described later.

  The spiral convex portions 11 and the concave portions 12 as described above can be formed by subjecting a metal tube, which is a raw material of the heat transfer tube T1, to a rolling process. According to the rolling process, when the male screw-like convex portion 11 is formed on the outer surface of the metal tube, the female screw-like concave portion can be simultaneously formed on the inner surface of the metal tube. Further, if the tube that has been subjected to the rolling process is further twisted, the pitch of the spiral convex portions 11 and the concave portions 12 can be reduced, which is more advantageous for increasing the surface area of the heat transfer tube T1. It becomes.

  The plurality of straight tubular body portions 1 are arranged so as to be substantially parallel to each other, and the first and second straight tubular body portions 1L and 1R are arranged as shown in FIG. 1B, for example. ing. In the drawing, the first straight tube portion 1L is denoted by “L”, and the second straight tube portion 1R is denoted by “R”. This also applies to other figures such as FIG. The first and second straight tube portions 1L, 1R are, for example, in a staggered arrangement, and in each of the columns (the columns in the vertical height direction, which are eight in the drawing), The first and second straight tube portions 1L and 1R are arranged so as to be alternately positioned one by one. Unlike the present embodiment, when a plurality of straight tube sections 1 are arranged in a matrix in the vertical and horizontal directions, the first and second straight tube sections 1L and 1R are added to the columns in the vertical direction. Thus, it is preferable that the horizontal rows are alternately arranged one by one. The total number of each of the first and second straight tube portions 1L and 1R is substantially the same (including the same number).

  Next, the operation of the heat exchanger HE1 described above will be described.

  When hot water heating is performed, a heating medium is caused to flow into the case 3 from the inlet 30 and water is supplied to the water supply port 21 to circulate water in each heat transfer tube T1. Since the spiral convex portion 11 and the concave portion 12 are formed on the outer surface and the inner surface of each heat transfer tube T1, the heat transfer area of the heat transfer tube T1 is increased as described in the background section. Moreover, it becomes possible to make the contact time between these and the heat transfer tube T1 longer by using a heating medium or water as a turbulent flow, and heat transfer efficiency is improved.

  In a hot water distribution path (not shown) communicating with the water supply port 21 and the hot water outlet 22, for example, when a water hammer is generated and the pressure in each heat transfer tube T <b> 1 becomes considerably high, each straight tube portion 1. A torsional force is generated at. As described above, this is because the spiral recess 12 is formed on the inner surface of each straight tube portion 1. The direction of the torsional force is opposite to the spiral winding direction of the recess 12. Therefore, as shown in FIG. 1B, a clockwise twisting force Ta is generated in the first straight tubular body portion 1L, whereas in the second straight tubular body portion 1R. Produces a counterclockwise torsional force Tb. Therefore, the rotational moments generated by each of these torsional forces Ta and Tb, that is, the rotational moments that cause the plurality of heat transfer tubes T1 and the headers 2A and 2B to rotate relative to each other are canceled or reduced. In particular, in the present embodiment, the number of the first and second straight tube portions 1L and 1R is substantially the same, and these are alternately arranged one by one in each column in the vertical direction so as to approach each other. Therefore, the rotational moments generated by the torsional forces Ta and Tb can be offset or reduced more appropriately.

  Thus, in this heat exchanger HE1, even if a phenomenon such as a water hammer occurs, a large rotational moment is not generated between the heat transfer tube T1 and the headers 2A and 2B so as to relatively rotate them. can do. As a result, it is possible to appropriately prevent a large stress from being generated at the connecting portion (such as a brazed portion) between the heat transfer tube T1 and the headers 2A and 2B and other portions, and to stabilize the mounting of these heat transfer tubes T1 and headers 2A and 2B And reliability can be improved.

  3 to 11 show other embodiments of the present invention. In these drawings, the same or similar elements as those of the previous embodiment are denoted by the same reference numerals as those of the previous embodiment.

  In the configuration shown in FIG. 3A, as a plurality of columns arranged in the vertical height direction of the plurality of straight tubular body portions 1, a row in which only the first straight tubular body portions 1L are arranged, There are rows in which only the straight tubular body portions 1R are arranged, and these rows are alternately located one row at a time in the horizontal direction. In the configuration shown in FIG. 2B, a column in which only the first straight tubular body portion 1L is arranged and a column in which only the second straight tubular body portion 1R is arranged are alternately arranged in two rows in the horizontal direction. Is located. In the configuration shown in FIG. 5C, a plurality of examples in which a plurality of straight tubular body portions 1 are collected together by only the first straight tubular body portion 1L, and a second straight tubular body portion. Only 1R is divided into a plurality of rows collected together.

  In any of the above-described configurations, it is possible to preferably cancel or reduce the rotational moment based on the torsional forces Ta and Tb generated in the first and second straight tube portions 1L and 1R, respectively. . As understood from these configurations, the specific arrangement of the first and second straight tube sections 1L and 1R can be various arrangements. This also applies to heat exchangers HE2 to HE6 having other configurations as described later.

In the heat exchanger HE2 shown in FIG. 4A, each heat transfer tube T2 is configured as a U-shaped tube, and one end portion of the pair of straight tube portions 1 passes through the curved tube portion 4. Connected to each other. Each other end of the pair of straight tube portions 1 is connected to the header 2A. Although the spiral concave portion 11 and the convex portion 12 are provided in each straight tubular body portion 1, they are not provided in the curved tubular body portion 4. Further, as the straight tubular body portion 1, as in the above-described embodiment, the first and second straight tubular body portions 1L and 1R are different from each other in the spiral winding directions of the convex portion 11 and the concave portion 12. Is provided. As shown in FIG. 4B, in the direction in which the heat transfer tubes T2 are arranged (in the horizontal direction in the drawing), the first and second straight tube portions 1L and 1R are alternately positioned one by one. Are lined up.

  According to the present embodiment, as in the above-described embodiment, the rotational moment based on the torsional forces Ta and Tb generated in the first and second straight tube portions 1L and 1R is reduced. It is possible. Each heat transfer tube T2 has a one-sided shape in which only one end side is connected to and restrained by the header 2A, and the other end side is a free end, and the heat transfer tubes T2 and the header 2A are relatively rotated. However, in this embodiment, such a situation can be prevented appropriately, although there is a possibility that the heat transfer tubes T2 may be distorted. The curved tubular body portion 4 is formed by bending the heat transfer tube T2, but the curved tubular body portion 4 is not provided with the spiral convex portion 11 and the concave portion 12, and therefore, Can be easily bent. That is, unlike the present embodiment, if the spiral convex portion 11 and the concave portion 12 are provided in the portion formed as the curved tubular body portion 4, the rigidity of the portion becomes high and bending is difficult. However, according to the present embodiment, such a situation is appropriately avoided.

  In the heat exchanger HE3 shown in FIG. 5A, one of the pair of straight tube portions 1 constituting one U-shaped tube as the heat transfer tube T2 is the first straight tube portion 1L. And the other is the second straight tube portion 1R. According to such a configuration, as shown in FIG. 5B, the first and second straight tube portions 1L and 1R are alternately arranged one by one in the lateral direction in which the plurality of heat transfer tubes T2 are arranged. In addition to being able to make it possible, the first and second straight tube sections 1L and 1R can be arranged side by side in the longitudinal direction. As will be understood from the present embodiment, when a plurality of straight tube portions are provided in one heat transfer tube, the spiral winding direction of the convex portions 11 and the concave portions 12 formed in the plurality of straight tube portions is as follows. However, they are not necessarily aligned in the same direction.

  In the heat exchanger HE4 shown in FIG. 6, the pair of straight tube sections 1 of the heat transfer tubes T2 are individually connected to the two headers 2B and 2C. These two headers 2B and 2C correspond to a configuration in which the header 2A shown in FIG. 4A and FIG. 5A is divided into two. The header 2B is for incoming water and the header 2C is for hot water. In this way, even when the pair of straight tube portions 1 of the heat transfer tube T2 configured as a U-shaped tube is individually connected to the two headers 2B and 2C, the implementation shown in FIG. 4 and FIG. The same effect as the form can be obtained. The configuration in which the header is divided into two is also applicable to the embodiment shown in FIG.

  In the heat exchanger HE5 shown in FIG. 7, each heat transfer tube T3 is configured as a meandering tube having a meandering shape as a whole. More specifically, each heat transfer tube T3 includes a plurality of curved tube portions 4a to 4c and a plurality of additional tube portions between a pair of straight tube portions 1 having one end connected to the header 2D. In this configuration, a straight tubular body portion 5 (a pair of straight tubular body portions 5 in the figure) is provided. The spiral convex portion 11 and the concave portion 12 are provided not only in the straight tubular body portion 1 but also in the additional straight tubular body portion 5. The convex tube portions 4 a to 4 c are not provided with the convex portion 11 and the concave portion 12. For example, the first and second straight tube portions 1L and 1R are alternately arranged one by one in the direction in which the heat transfer tubes T3 are arranged (in the vertical direction in the figure). They are arranged side by side.

In the present embodiment, the overall length of each heat transfer tube T3 can be increased, which is advantageous for increasing the entire heat transfer area. In addition, since the additional straight tubular body portion 5 is also provided with the spiral convex portion 11 and the concave portion 12 in the same manner as the straight tubular body portion 1, this portion is also similar to the straight tubular body portion 1. Similarly, the heat transfer efficiency becomes a favorable part, which is more preferable for obtaining high heat exchange efficiency. Note that the additional straight tube portion 5 is not directly connected to the header 2D, and even if a torsional force is generated in the additional straight tube portion 5, the header 2D and the heat transfer tube T3 There is almost no rotation moment that tries to rotate the. Therefore, regardless of the spiral winding direction of the convex portion 11 and the concave portion 12 provided in the additional straight tube portion 5, the straight tube portion 1 connected to the additional straight tube portion 5 is provided. Either the same or non-identical winding direction of the convex portion 11 and the concave portion 12 may be used.

  In the heat exchanger HE6 shown in FIG. 8, each heat transfer tube T4 is configured to have a helical loop tube portion LO that is oval in plan view. More specifically, in this heat exchanger HE6, it has headers 2E and 2F for water entry and hot water provided separately in the upper and lower sides, and as a plurality of straight tubular body parts 1, A plurality of lower straight tubular body portions 1 whose one end portions are connected to the lower water intake header 2E via the curved pipe 90, and a plurality of one end portions connected to the upper hot water header 2F. There is an upper straight tube portion 1.

  Each straight tube portion 1 passes through the wall portion 32 of the case 3A, and is fixed to the wall portion 32 by means such as brazing. Therefore, in the present embodiment, the case 3A corresponds to the “connecting member” in the present invention, and the torsional force generated in the straight tubular body portion 1 is caused by the wall portion 30 of the case 3A and the plurality of heat transfer tubes T4. There is a possibility of generating a rotational moment that attempts to rotate them relative to each other. Since the headers 2E and 2F are located outside the case 3A, they do not receive the torsional force described above. The plurality of lower and upper straight tube portions 1 are each arranged in a line in a substantially horizontal direction. In such an arrangement, the first and second straight tube portions 1L and 1R are They are lined up alternately in a substantially horizontal direction.

  The spiral loop tube portion LO has a configuration in which a plurality of loop portions having an oval shape in plan view are connected in series and stacked in the vertical direction. The loop portion extends in the same direction as the straight tube portion 1 and is paired with a pair of additional straight tube portions 5A that are spaced apart in the front-rear direction of the case 3A, and the pair of additional straight shapes. It has the curved pipe parts 4e and 4f which connect the both ends of the pipe part 5A. The plurality of heat transfer tubes T4 are configured so that the sizes of the spiral loop tube portions LO are different from each other, and these spiral loop tube portions LO are substantially concentrically overlapped. The spiral loop tube portion LO has a lower end portion connected to one end of the lower straight tube portion 1 and an upper end portion connected to one end of the upper straight tube portion 1. Although not shown in the drawing, the spiral loop tube portion LO is supported by using an appropriate support member in the case 3A, and is provided so as not to cause an inadvertent displacement. On the outer surface and inner surface of the additional straight tubular body portion 5 </ b> A, similarly to the straight tubular body portion 1, spiral convex portions 11 and concave portions 12 are formed. Convex portions 11 and concave portions 12 are not formed in the curved tubular body portions 4d and 4e.

In the present embodiment, since each heat transfer tube T4 has the spiral loop tube portion LO, it is possible to lengthen the overall length and significantly increase the heat transfer area while suppressing the overall bulkiness. it can. Therefore, it is more preferable to obtain a high heat exchange efficiency while reducing the overall size by reducing the total number of heat transfer tubes T4. In the additional straight tubular body portion 5A, since the spiral convex portion 11 and the concave portion 12 are formed, it is possible to further improve the heat exchange efficiency. On the other hand, the plurality of straight tube portions 1 are fixed to the wall portion 32 of the case 3A in a state where the first and second straight tube portions 1L and 1R are alternately arranged in a substantially horizontal direction one by one. Therefore, even if the pressure in each heat transfer tube T4 becomes considerably high and a torsional force is generated in each of the first and second straight tube portions 1L and 1R, the first straight shape The rotational moment based on the torsional force generated in the tubular body portion 1L and the rotational moment based on the torsional force generated in the second straight tubular body portion 1R are also canceled out or reduced. Therefore, the generation of a rotational moment that attempts to relatively rotate the plurality of heat transfer tubes T4 and the wall portion 30 of the case 3A is appropriately prevented or suppressed. As a result, for example, a large stress due to the rotational moment can be prevented from being generated at the brazed portion between the heat transfer tube T4 and the wall portion 30 and other support portions of the heat transfer tube 4.

  In the heat exchanger HE7 shown in FIG. 9, each of the plurality of heat transfer tubes T5 is divided into first and second regions A1 and A2, and these regions A1 and A2 are divided into the first and second direct passages. It is formed as a cylindrical tube portion 1R, 1L. As clearly shown in FIG. 10, the first and second straight tube portions 1R and 1L are arranged in the longitudinal direction of the heat transfer tube T5 with the non-spiral portion 10a at the substantially central portion in the longitudinal direction of the heat transfer tube T5 interposed therebetween. Lined up in series in the direction. The non-spiral portion 10a is a portion for clamping the raw material pipe when the raw material pipe is twisted to produce the heat transfer tube T5. In this heat exchanger HE7, the plurality of heat transfer tubes T5 are all in the same direction (for example, the direction in which the first straight tube portion 1R is located on the left side and the second straight tube portion 1L is located on the right side). ). The configuration of the heat exchanger HE7 shown in FIG. 9 other than the heat transfer tube T5 is the same as that of the heat exchanger HE1 shown in FIG.

  In the present embodiment, when water hammer occurs in a hot water distribution path (not shown) communicating with the water supply port 21 and the hot water outlet 22 and the pressure in each heat transfer tube T5 becomes considerably high, A counterclockwise twisting force Tc is generated in the first straight tubular body portion 1R, and a clockwise twisting force Td is generated in the second straight tubular body portion 1L. When such two torsional forces Tc and Td are generated in each heat transfer tube T5, they are offset or reduced. Therefore, it is possible to reduce the torsional force of each heat transfer tube T5 acting on the connection portion between each heat transfer tube T5 and the headers 2A and 2B, and to prevent a large stress from being generated in the connection portion.

  As will be understood from the embodiment shown in FIGS. 9 and 10, in the present invention, the plurality of heat transfer tubes have the first straight tube portion and the second straight tube portion. It can replace with using a thing and can also be set as the structure using what has the 1st and 2nd straight pipe | tube part arranged in series in the longitudinal direction of the pipe. In the case where the first and second straight tube sections are arranged in series on one heat transfer tube, the heat transfer tube to be applied is not limited to a heat transfer tube extending in a straight line. For example, even in a U-shaped tube, a meandering tube, and a heat transfer tube such as a spiral shape as shown in FIGS. 4 to 8, both the first and second straight tube portions are included in the straight portion. Can be provided appropriately.

  In the heat exchanger HE8 shown in FIG. 11, the directions of the plurality of heat transfer tubes T5 (the left and right arrangements of the first and second straight tube portions 1R, 1L) are not the same, and the plurality of heat transfer tubes In the arrangement direction of T5, the first and second straight tube portions 1R and 1L are set to be alternately positioned. According to such a configuration, in addition to the effect that the torsional forces Tc and Td generated in each heat transfer tube T5 cancel each other or are reduced, the rotational moment acting on the headers 2A and 2B from the adjacent heat transfer tubes T5. Will be offset or reduced. Therefore, it is more preferable in reducing the stress generated at the connecting portion between each heat transfer tube T5 and the headers 2A and 2B.

  The present invention is not limited to the contents of the above-described embodiment. The specific configuration of each part of the heat exchanger according to the present invention can be varied in design in various ways.

In the above-described embodiments, the heat transfer tubes are configured as so-called straight tubes, U-shaped tubes, serpentine tubes, and spiral loop tubes. However, the heat transfer tubes can be formed in other forms. In short, the heat transfer tube has only to have at least a part of the straight tube body, and a spiral recess may be formed on the inner surface of the straight tube body. The spiral recess may not be formed over the entire length region of the inner surface of the straight tube portion, and may be formed only in a part of the straight tube portion. Further, the spiral concave portion may be formed using means other than rolling or twisting, such as cutting. From the viewpoint of increasing the heat transfer efficiency, although it is preferable to provide a spiral convex portion on the outer surface of the straight tubular body portion, a configuration in which this convex portion is not formed can also be adopted. Moreover, it can replace with a helical convex part, and can also be set as the structure which provided the fin for heat exchanges, such as a non-spiral simple disk shape, in the outer surface part of each heat exchanger tube, and improved the heat transfer efficiency.

  The first and second straight tube portions referred to in the present invention are only required to have different spiral winding directions of the concave portions formed on the inner surfaces thereof. Contrary to the above-described embodiment, the one in which the spiral winding direction of the concave portion is in the right direction may be referred to as the first straight tube portion, and the left direction may be referred to as the second straight tube portion. . There may be differences between the first and second straight tube portions other than the spiral winding direction of the recesses, for example, differences in items such as the number of recesses, the pitch, or the overall tube length. There is no problem. As a connection member as used in the field of this invention, although a header and the case surrounding a heat exchanger tube can be mentioned as a specific example like embodiment mentioned above, it is not limited to these as well.

  The heat exchanger according to the present invention is not limited to that for a hot water supply apparatus. Instead of heating the fluid, it can also be used for cooling. Therefore, the type of medium that acts on the outer surface of the heat transfer tube is not limited. Various fluids other than water or gas (including water vapor) can be applied as the fluid flowing through the heat transfer tube.

HE1 to HE8 heat exchangers T1 to T5 Heat transfer tube 1 Straight tube portion 1L First straight tube portion 1R Second straight tube portion 2A to 2D Header (connection member)
3A case (connecting member)
4, 4a to 4e Curved tube portions 5, 5A Additional straight tube portion 11 Spiral convex portion 12 Spiral concave portion

Claims (7)

A plurality of heat transfer tubes, and a connecting member fixedly connected to the plurality of heat transfer tubes,
The plurality of heat transfer tubes have a plurality of straight tube portions extending in substantially the same direction from a connection position with the connecting member, and a spiral recess is formed on the inner surface of the plurality of straight tube portions. A heat exchanger formed,
As the plurality of straight tubular body portions, first and second straight tubular body portions are provided, and the first and second straight tubular body portions are arranged such that the spiral winding direction of the concave portion is mutually A heat exchanger characterized in that it is different.   The heat exchange according to claim 1, wherein a heat transfer tube having the first straight tubular body portion and a heat transfer tube having the second straight tubular body portion are provided as the plurality of heat transfer tubes. vessel.   The heat exchanger according to claim 2, wherein the number of each of the first and second straight tube portions is substantially the same.   The plurality of straight tube portions are arranged in one or a plurality of rows, and in each of the rows, the first and second straight tube portions are alternately positioned one by one. The heat exchanger according to claim 3, which is lined up.   All or some of the plurality of heat transfer tubes have both the first and second straight tube portions, and the first and second straight tube portions are in series in the longitudinal direction of the tube. The heat exchanger according to any one of claims 1 to 4, wherein the heat exchanger is configured in a line.   The heat exchanger according to any one of claims 1 to 5, wherein a spiral convex portion is formed on an outer surface of each straight tube portion. Each of the heat transfer tubes further includes an additional straight tube portion connected to each of the straight tube portions via a curved tube portion,
The heat exchanger according to any one of claims 1 to 6, wherein spiral concave portions and convex portions are also formed on the inner surface and the outer surface of the additional straight tubular body portion.

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