JP2010048424A - Heat exchanger, and water heater equipped therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger capable of enhancing drainability when executing draining work from a plurality of spiral pipe bodies connected to a header. <P>SOLUTION: A chamber 64 of the header 6 equipped in the heat exchanger is communicated with an inside of each lower end part of plurality of overlappedly wound spiral pipe bodies via a plurality of communication passages 2A-2E. A plurality of opening parts 20a opened toward the chamber 64 out of the communication passages 2A-2E are made uneven in heights Ha-He thereof, and the plurality of communication passages 2A-2E is constituted to make the heights of the opening parts 20a corresponding to outer circumferential side pipe bodies lower than those of corresponding to inner circumferential side pipe bodies. The plurality of communication passages 2A-2E is constituted preferably to make all the heights of the opening parts 20a different each other, and to make the heights of the opening parts 20a get lower sequentially along with advance from that corresponding to the innermost circumferential spiral pipe bodies toward that corresponding to the outermost circumferential spiral pipe bodies. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a heat exchanger used for recovering heat from a heat medium such as combustion gas using a helical tube, and a hot water apparatus such as a hot water supply apparatus provided with the heat exchanger.

  The present applicant has previously proposed a heat exchanger using a helical tube described in Patent Document 1. In the heat exchanger described in the same document, a plurality of helical tubes having different winding sizes are provided in a substantially concentric overlapping shape in a case where combustion gas is introduced. By using this to recover heat from the combustion gas, hot water in each helical tube is heated.

  In the heat exchanger, a structure as shown in FIG. 11 of the present application is adopted as hot water supply means to each spiral tube. In this structure, the header 4 is connected to the lower end 90 projecting outside the case 78 among the plurality of spiral tubes 9 (9A to 9E) via the curved tubes 8 (8A to 8E). Yes. Using this header 4, hot water can be supplied to each helical tube 9. The curved tube 8 is configured to make the header 4 lower than the lower end portion 90 of each helical tube 9 by an appropriate height h. According to such a configuration, for example, in order to prevent the inside of the spiral tube body 9 from freezing in the winter season, when performing the water draining operation in each spiral tube body 9, each spiral tube The operation in which water flows into the header 4 from the lower end portion 90 of the body 9 can be smoothly performed using the height difference h.

  However, in the prior art, there are still points to be improved as described below.

  That is, in the prior art, when draining water by flowing water into the header 4 from the plurality of spiral tubes 9, when draining from all of the plurality of spiral tubes 9, As shown in FIG. 12A, the chamber 40 of the header 4 can be filled with water. However, since the plurality of spiral tubes 9 are different in length and the overall length of the innermost spiral tube 9A is the shortest, the drainage of the spiral tube 9A is first performed. After that, draining of the spiral tubular bodies 9B to 9E will be completed. In this case, for example, when only the spiral tubes 9A and 9B located near the inner periphery are drained, and other spiral tubes 9C to 9E are not yet drained, As shown in FIG. 12B, an air region 48 is generated in the upper part of the chamber 40. On the other hand, the heights of the lower end openings 80 of the plurality of curved tubes 8A to 8E are substantially equal to each other. For this reason, the air region 48 is also generated below the curved tubes 8C to 8E that have not yet been drained. In this state, an air layer is interposed between the curved tubes 8C to 8E and the water flow port 41. In order to improve the water drainage of each spiral tube 9, as understood from the principle of siphon, an air layer is interposed over the entire length of a series of paths from each spiral tube 9 to the water passage 41. Instead, it is desirable to fill with water. However, in the past, it has been difficult to achieve such a state. For this reason, when each helical tube 9 is a thin tube having a considerably small diameter, it may be difficult to drain water appropriately.

JP 2007-333343 A

  The present invention has been conceived under the circumstances as described above, and it is possible to improve drainage performance when performing drainage work from a plurality of spiral tubular bodies to which headers are connected. It is an object of the present invention to provide a possible heat exchanger and a hot water device provided with the heat exchanger.

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

The heat exchanger provided by the first aspect of the present invention includes a plurality of spiral tubes arranged in a substantially concentric wrapping manner with a central axis extending in a substantially vertical direction, and a water passage at the bottom A heat exchanger comprising: a header having a hot water inflow chamber formed therein; and a plurality of communication passages connecting the chamber to the inside of each lower end portion of the plurality of spiral tubes. Of the first and second openings formed at both ends of the plurality of communication passages, the heights of the plurality of first openings opened toward the chamber are non-uniform, The plurality of communication passages have a configuration in which the height of the first opening is lower in the one corresponding to the outer spiral tube than in the inner periphery. It is characterized by having.
More preferably, the plurality of communication passages are configured such that the heights of the first openings are all different from ones corresponding to the innermost spiral tube and the outermost spiral tube. The height of the first opening gradually decreases as the process proceeds to the one corresponding to.

According to such a configuration, the following effects can be obtained.
That is, when water in a plurality of spiral tubes is drained by flowing into the header chamber via a plurality of communication passages, for example, the innermost spiral tube having the shortest overall length dimension. Even if the draining of the water is finished and an air region is generated in the chamber, the first opening portion of the communication path corresponding to the other spiral tube body is low, so there is no air region below it. Can be. Similarly, even when draining of the second spiral tube from the innermost periphery is completed, there is no air region below the communication path corresponding to the spiral tube closer to the outer periphery. Can be. As described above, in the present invention, an air region is prevented from being generated below the communication path corresponding to the spiral tubular body that has not been drained, and a series from the communication path to the header water inlet. It is possible to prevent an air layer that becomes a factor that deteriorates drainage performance from occurring in the path. As a result, it is possible to improve the drainage performance when water is drained from a plurality of spiral tubes, and it is possible to appropriately cope with a case where each spiral tube is a thin tube having a considerably small diameter.

  In a preferred embodiment of the present invention, the chamber is disposed lower than the lower ends of the plurality of spiral tubes, and the first openings of the plurality of communication passages are located above the chamber. The plurality of first openings are different in height because they open to the wall and the upper wall of the chamber is inclined upward and downward.

  According to such a configuration, since there is a difference in height between the chamber and each lower end portion of the plurality of spiral tubes, at the time of draining work, the difference in height is used to move from the spiral tube to the chamber. Can promote the inflow of water. In addition, if a plurality of first openings are opened in the inclined upper wall portion of the chamber, it is possible to easily realize different heights of the plurality of first openings, and formation of a plurality of communication paths. Becomes easy.

  In a preferred embodiment of the present invention, the water inlet is located immediately below the first opening of the communication passage corresponding to the outermost spiral tube, and is formed on the bottom wall of the chamber. The whole or a part is inclined in substantially the same direction as the upper wall portion.

  According to such a configuration, it is possible to reduce the volume of the chamber and reduce the size and weight of the header.

  In a preferred embodiment of the present invention, the chamber has a shape in which a side wall portion extends in a substantially vertical direction, and the first openings of the plurality of communication passages are arranged in a substantially vertical direction. Opened in the side wall of the chamber.

  According to such a configuration, the height difference between the first openings of the plurality of communication paths can be increased while suppressing an increase in the size of the header. As the height difference between the first openings is increased, it is possible to make it difficult to generate an air region below the communication path where drainage is not completed.

  In a preferred embodiment of the present invention, at least the header body forming the chamber among the headers is made of a synthetic resin, and the plurality of communication paths are formed in the header body.

  According to such a configuration, compared with the case where the header is made of metal, for example, manufacturing can be facilitated and raw material costs can be reduced, and the manufacturing cost can be reduced. Further, it is possible to suitably reduce the weight of the header.

  In a preferred embodiment of the present invention, the second openings of the plurality of communication passages are provided to open on one side surface of the header body, and the plurality of second openings are provided with the plurality of the plurality of communication paths. The header and the plurality of spiral tubes are connected by fitting the lower end of the spiral tube.

  According to such a configuration, the connection between the communication path and each helical tube is facilitated, and the manufacturing cost can be further reduced.

  The hot water apparatus provided by the second aspect of the present invention is a hot water apparatus comprising: a combustor that generates combustion gas; and a heat exchanger that recovers heat from the combustion gas. As the exchanger, the heat exchanger provided by the first aspect of the present invention is used.

  According to such a configuration, the same effect as described for the heat exchanger provided by the first aspect of the present invention can be obtained.

  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.

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

  1 to 8 show an example of a hot water apparatus to which the present invention is applied and a configuration related thereto. As shown well in FIG. 1, the hot water device WH of the present embodiment includes a combustor 3, a primary heat exchanger 1, and a secondary heat exchanger HE. The secondary heat exchanger HE corresponds to an example of a heat exchanger to which the present invention is applied.

  The combustor 3 and the primary heat exchanger 1 have the same configuration as that described in Patent Document 1 described in the background art section. That is, the combustor 1 is a positive combustion type gas burner, for example, and is disposed in the case 30 and supplied with fuel gas from the outside via the pipe 32. Combustion air is blown upward from the blower fan 31 into the case 30. The primary heat exchanger 1 is for recovering sensible heat from the combustion gas generated by the combustor 3, and has a structure in which a heat transfer tube 11 having a plurality of fins 12 is arranged in a case 10. ing.

  The secondary heat exchanger HE is for recovering latent heat from the combustion gas, and is disposed above the primary heat exchanger 1 and connected to the case 10 via an auxiliary case 19. . The secondary heat exchanger HE includes a case 7 into which combustion gas is introduced, a plurality of spiral tubes 5 as heat transfer tubes, and headers 6 and 77 for incoming and outgoing hot water.

  The case 7 has a hollow, substantially rectangular parallelepiped shape and surrounds the plurality of spiral tubular bodies 5. As shown in FIGS. 2 and 3A, the rear wall portion 70 a and the front wall portion 70 b of the case 7 are provided with an air supply port 71 and an exhaust port 72. As shown in FIG. 2, the combustion gas that has passed through the primary heat exchanger 1 and has traveled upward enters the case 7 through the air supply port 71, and the latent heat is recovered by the plurality of spiral tubes 5. Is done. The combustion gas that has finished the recovery of latent heat is then discharged from the exhaust port 72 to the outside of the case 7.

  As shown in FIGS. 3A and 3B, the plurality of spiral tubular bodies 5 (5 </ b> A to 5 </ b> E) are configured such that their central axes C extend in a substantially vertical direction, and are elliptical in plan view. In this configuration, straight tubular extending portions 51 and 52 are integrally or separately provided at the lower end and the upper end of the spiral portion 50. One end of each of the extending portions 51 and 52 passes through the side wall 70e of the case 7 and is drawn out of the case 7 so as to be connected to the headers 6 and 77. In addition, the spiral tube referred to in the present invention means a heat transfer tube whose main part is formed as a spiral tube, and the entire tube does not have to be spiral. It is also a concept that includes a body part. The winding sizes of the plurality of spiral tubular bodies 5 are different from each other, and these are substantially concentric lap windings. In such a lap winding structure, the total length of the innermost spiral tube 5A is the shortest, and the total length of the outermost spiral tube 5E is the longest.

  The header 6 is for supplying hot water to each spiral tube 5, but when draining water from each spiral tube 5, each spiral tube is opposite to when supplying hot water. Water flows into the header 6 from 5. As shown in FIG. 4, the header 6 is attached to the side wall 70 e of the case 7 using, for example, a screw body 69, and includes a header body 60, a base plate 61, and a cover 62. These are all made of synthetic resin. The base plate 61 and the cover 62 are members for attaching the header body 60 to the case 7 in a good appearance.

  The header body 60 can be a single resin molded product. The header body 60 includes a hot water inflow chamber 64 having a water passage 63 formed in the lower portion, and a plurality of communication passages 2 connected to the upper portion of the chamber 64. Forming. A water supply pipe (not shown) is connected to the cylindrical portion 63a that forms the water flow port 63, and water is introduced into the chamber 64 from the water supply pipe during hot water supply operation, and from each communication passage 2 into each spiral pipe body 5. Water can be supplied to The communication path 2 is bent in a substantially L shape, and an upper opening 20b (corresponding to an example of the second opening of the communication path in the present invention) is opened on one side surface of the header body 60. is doing. As shown in FIGS. 5 and 6, the lower end portion 53 of each helical tube 5 protrudes to the outside of the case 7, and has a structure in which an O-ring 59 for water-stopping sealing is mounted on the outer periphery thereof. It is said that. The header 6 is attached so that the upper opening 20b of each communication passage 2 is fitted to the lower end 53 of each helical tube 5.

  As shown in FIG. 7, the upper wall portion 65 of the chamber 64 is inclined up and down. On the other hand, the lower openings 20a (corresponding to an example of the first opening of the communication path in the present invention) of the plurality of communication paths 2A to 2E are opened in the upper wall 65. Accordingly, the heights Ha to He of the lower openings 20a of the communication paths 2A to 2E are different from each other. More specifically, the height Ha of the communication passage 2A communicating with the innermost spiral tube body 5A is the highest, and the relationship of Ha> Hb> Hc> Hd> He is established. The water flow port 63 is located immediately below the communication passage 2E, and the lower wall portion 66 of the chamber 64 is inclined upward and downward so as to be substantially parallel to the upper wall portion 65 from the peripheral edge of the communication passage 2E. . If the lower wall portion 66 is inclined substantially parallel to the upper wall portion 65 in this way, the width W1 of the chamber 64 is made substantially constant, the volume of the chamber 64 is reduced, and the overall volume of the header body 60 is reduced. This is preferable.

  The hot water header 77 is connected to the upper end of each helical tube 5, and unlike the above-described header 6, water does not flow into the interior during the draining operation. For this reason, this header 77 does not employ a structure like the header 6, and has a structure in which a hot water outlet 77 a is provided at an appropriate position of a hollow member connected to the upper end of each spiral tube 5, for example. Has been. As shown in FIG. 1, the hot water outlet 77 a is connected to the water inlet 11 a of the primary heat exchanger 1 through an appropriate pipe 81. The primary heat exchanger 1 is configured such that hot water sent from the secondary heat exchanger HE passes through the heat transfer pipe 11 and is further heated. It is sent toward the desired hot water supply destination from the hot water outlet 11b.

  Next, the operation of the above-described secondary heat exchanger HE and the hot water device WH provided with the same will be described.

  First, in FIG. 1, when water is passed through the plurality of spiral tubes 5 of the secondary heat exchanger HE and the heat transfer tubes 11 of the primary heat exchanger 1, the combustor 3 starts to be driven. Then, sensible heat and latent heat are sequentially recovered from the combustion gas generated by the combustor 3 by the primary heat exchanger 1 and the secondary heat exchanger HE. The hot water generated by this heat recovery is supplied from a hot water outlet 11b to a desired hot water supply destination.

  Next, for example, in winter, when the operation of the hot water apparatus WH is stopped for a long period of time, in order to prevent freezing in the primary heat exchanger 1 and the secondary heat exchanger HE, the heat transfer tubes 11 and the respective Water entry into the spiral tubular body 5 is stopped and the water draining operation is performed. At that time, as described below, it is possible to improve drainage from the secondary heat exchanger HE.

  That is, at the beginning of draining, water flows into the chamber 64 from all of the plurality of communication passages 2A to 2E, so that the chamber 64 is filled with water. Thereafter, when draining is continued, as shown in FIG. 8A, drainage from the communication passage 2 </ b> A connected to the spiral tubular body 5 </ b> A having the shortest overall length is stopped, and an air region is formed in the chamber 64. AR occurs. However, this air region AR occurs at the top of the chamber 64 and does not exist directly below the communication passages 2B to 2E. Therefore, an air layer that impedes drainage is not interposed between each of the communication passages 2B to 2E and the water passage 63, and the water is filled, and the communication passages 2B to 2E are similar to the siphon principle. From the water to the water outlet 63 is appropriately performed. Next, as shown in FIG. 5B, even when drainage from the communication passage 2B corresponding to the spiral tubular body 5B is stopped, the air region AR does not exist immediately below the communication passages 2C to 2E. Thus, the water is appropriately distributed from the communication passages 2C to 2E to the water flow port 63. Thereafter, as described above, drainage is stopped in the order of the communication passages 2C, 2D, and 2E. At that time, an air region AR is generated below the communication passage that has not yet been drained. You can avoid it. As a result, it is possible to accurately perform the water draining operation for all of the plurality of spiral tubular bodies 5A to 5E.

  In this embodiment, since the header 6 is made of a synthetic resin, the header 6 is made of metal, for example, so that the manufacture becomes easy and the manufacturing cost can be reduced, and the weight can be reduced. Can do. Further, as shown in FIG. 5, it is possible to easily perform the work of attaching the header 6 to the case 7 so as to be fitted to the respective spiral tubular bodies 5, and the manufacturing cost of the secondary heat exchanger HE. Can be made cheaper.

  9 and 10 show another embodiment of the present invention. In these drawings, elements that are the same as or similar to those in the above embodiment are given the same reference numerals as in the above embodiment.

  In the header 6A shown in FIG. 9, a part of the lower wall part 66 of the chamber 64 is an inclined part 66a, and the other part is a horizontal part 66b having a relatively large area. According to the present embodiment, the volume of the chamber 64 is larger than that of the header 6 shown in the above embodiment, but the water flow port 63 can be provided at a position off from directly below the communication path 2E. The freedom degree of arrangement of 63 increases.

  In the header 6B shown in FIG. 10, the side wall 67 of the chamber 64 extends in a substantially vertical direction, and the openings 20a of the plurality of communication passages 2A to 2E are arranged in the substantially vertical direction. 67 is open. In the present embodiment, the height difference between the openings 20a of the plurality of communication passages 2A to 2E can be increased while suppressing an increase in the size of the header 6B. When the height difference between the plurality of openings 20a is increased, there is an advantage that an air region can be more unlikely to be generated below the opening 20a of the communication path 2 where drainage is not completed when draining. Note that the communication path 2A shown in FIG. 10 is not shaped to be bent downward, but the communication path of the present invention may be configured as described above.

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

  In the present invention, it is preferable that the heights of the first openings of the plurality of communication paths 2A to 2E (for example, heights Ha to He in FIG. 7) are all different as in the above-described embodiment. However, it is not limited to this. Compared with the embodiment described above, although the water draining performance is somewhat inferior, for example, among the plurality of communication passages 2A to 2E, the height of any one of the first openings is the same or substantially the same. It may be configured in a uniform manner (a configuration in which the heights Ha to He have a relationship of Ha> Hb> Hc> Hd = He, for example), and this case is also included in the technical scope of the present invention. Some of the plurality of first openings that are aligned at the same or substantially the same height may be present in part. Even in such a case, the configuration in which the heights Ha to He of all the first openings of the plurality of communication passages 2A to 2E are substantially equal to each other (configuration corresponding to the prior art) This is because the drainage performance can be improved.

  In the present invention, from the viewpoint of reducing the manufacturing cost, it is preferable that the header is made of synthetic resin and a plurality of communication paths are formed in the header as in the above-described embodiment. However, it is not limited to this, and these may be made of metal, for example. That is, in this invention, it can also be set as the structure which connected the metal pipe | tube body, for example to the metal hollow header. In this case, the inside of the tubular body corresponds to the communication path in the present invention. In the above-described embodiment, the second openings (upper openings 20b) of the plurality of communication passages are arranged at substantially the same height, but unlike these, It does not matter if the height is uneven.

  As described above, the spiral tube body may include a tube portion other than the spiral shape, but the shape of the spiral portion is a rectangular shape or a circular shape in plan view instead of a substantially oval shape in plan view. Various shapes such as a shape can be used. Further, the spiral tube body may be provided in a plurality in a posture in which the central axis extends in a substantially vertical direction, and these may be arranged in an overlapping manner, and the specific number, material, aperture, etc. are not limited.

  In the embodiment described above, the present invention is not applied to the primary heat exchanger for sensible heat recovery, but the heat exchanger according to the present invention asks the type for sensible heat recovery and latent heat recovery. is not. In addition, the object (heat medium) for heat recovery by the heat exchanger may be other than the combustion gas. The hot water device as used in the present invention means a device having a function of generating hot water, and is used for various types of hot water supply devices for general hot water supply, bath hot water supply, heating, snow melting, and the like, and hot water supply. It is a concept that includes a wide range of equipment for producing hot water.

It is a schematic front sectional view showing an example of a hot water device to which the present invention is applied. It is II-II sectional drawing of FIG. (A) is a plane sectional view of the secondary heat exchanger of the hot-water apparatus shown in Drawing 1, and (b) is the front sectional view. It is sectional drawing which shows the structure of the header which the secondary heat exchanger of the hot water apparatus shown in FIG. 1 comprises, and its peripheral part. FIG. 5 is an exploded cross-sectional view of a main part of FIG. 4. It is VI-VI plane sectional drawing of FIG. It is VII-VII principal part sectional drawing of FIG. (A), (b) is an effect | action explanatory drawing of the structure part shown in FIG. It is principal part sectional drawing which shows the other example of the header of the heat exchanger to which this invention was applied. It is principal part sectional drawing which shows the other example of the header of the heat exchanger to which this invention was applied. It is a principal part perspective view which shows an example of a prior art. (A), (b) is principal part sectional drawing which shows the effect | action of the prior art shown in FIG.

Explanation of symbols

WH water heater HE secondary heat exchanger (an example of a heat exchanger to which the present invention is applied)
C Center axis (for spiral tube)
2 (2A to 2E) Communication path 3 Combustor 5 (5A to 5E) Spiral tubular body 6, 6A, 6B Header 20a Lower opening (first opening of communication path)
20b Upper opening (second opening of communication path)
60 Header body 63 Water inlet 64 Chamber 65 Upper wall (chamber)
66 Lower wall (chamber)
67 Side wall (chamber)

Claims (8)

A plurality of helical tubes arranged in a substantially concentric lap winding with a central axis extending in a substantially vertical direction;
A header having a hot water inflow chamber having a water passage formed at the bottom;
A plurality of communication passages connecting the chamber to the inside of each lower end portion of the plurality of helical tubes;
A heat exchanger comprising:
Of the first and second openings formed at both ends of the plurality of communication paths, the heights of the plurality of first openings opened toward the chamber are non-uniform, The communication passage has a configuration in which the height of the first opening is lower in the one corresponding to the spiral tube on the outer peripheral side than in the one corresponding to the spiral tube on the inner peripheral side. A heat exchanger characterized by that.   The plurality of communication passages are configured such that the heights of the first openings are all different and correspond to the outermost spiral tube from the innermost spiral tube. The heat exchanger according to claim 1, wherein the height of the first opening gradually decreases as the process proceeds to step (a). The chamber is arranged lower than the lower ends of the plurality of spiral tubes, and the first openings of the plurality of communication passages open to the upper wall of the chamber,
The heat exchanger according to claim 1 or 2, wherein heights of the plurality of first openings are different because an upper wall portion of the chamber is vertically inclined.   The water flow port is located immediately below the first opening of the communication passage corresponding to the outermost spiral tube body, and the whole or a part of the bottom wall portion of the chamber is the upper wall portion. The heat exchanger according to claim 3, wherein the heat exchanger is inclined in substantially the same direction. The chamber has a shape in which a side wall portion extends in a substantially vertical direction,
The heat exchanger according to claim 1 or 2, wherein the first openings of the plurality of communication passages are opened in a side wall of the chamber so as to be arranged in a substantially vertical direction. Among the headers, at least the header body forming the chamber is made of synthetic resin,
The heat exchanger according to claim 1, wherein the plurality of communication passages are formed in the header body. The second openings of the plurality of communication passages are provided to open on one side of the header body,
The header and the plurality of spiral tubes are connected to each other by inserting lower ends of the plurality of spiral tubes into the plurality of second openings. Heat exchanger. A hot water apparatus comprising: a combustor that generates combustion gas; and a heat exchanger that recovers heat from the combustion gas,
A hot water device, wherein the heat exchanger according to any one of claims 1 to 7 is used as the heat exchanger.

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