JP2007315666A - Heat exchanger and water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger which properly prevents difficulty in draining from a water tube when the water tube having a spiral tube body part is narrowed. <P>SOLUTION: The heat exchanger B is provided with: a can body 2 having a circumferential wall part 20; a heat exchange water tube 4 having the spiral tube body part 40 arranged in the can body 2 in an attitude with a center axis extending in a vertical direction, and auxiliary tube body parts 41A connected to a lower end of the spiral tube body part 40 and piercing the circumferential wall part of the can body 2 with tip side portions protruding to an exterior of the can body 2; and a header 5A for water inflow or hot water outflow arranged in the exterior of the can body 2 and connected to tips of the auxiliary tube body part 41A. Of the auxiliary tube body parts 41A, in a portion protruding to the exterior of the can body, a bent part 411 is formed such that a height becomes lower toward a tip side portion of the auxiliary tube body part 41A. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a so-called spiral water tube type heat exchanger and a hot water apparatus including the heat exchanger.

  The present applicant has previously proposed, for example, one described in Patent Document 1 as a specific example of a hot water apparatus including a spiral water tube type heat exchanger. The heat exchanger of the hot water device described in the same document includes a can body in which combustion gas is supplied and a plurality of water pipes having a plurality of helical tube portions arranged in the can body. . Auxiliary tube portions are extended from the upper and lower ends of the helical tube portions of the plurality of water tubes, and a pair of headers are connected to these auxiliary tube portions. By using these pair of headers, it is possible to enter and exit the plurality of water pipes. In this heat exchanger, after the combustion gas introduced into the can is passed through a part of the plurality of spiral tube parts to perform the first heat recovery, the other part also The second heat recovery is performed by passing it through. Thus, sensible heat and latent heat can be recovered from the combustion gas, and high heat exchange efficiency can be obtained. As in the case of Patent Document 1, the applicant of the present invention also discloses a hot water apparatus provided with a spiral water tube type heat exchanger capable of recovering sensible heat and latent heat from combustion gas as described in Patent Documents 2 and 3. Proposed earlier.

  However, the prior art has still to be improved as described below.

  That is, from the viewpoint of increasing the heat exchange efficiency while reducing the size of the entire heat exchanger, it is desired to make the water pipe narrower. This is because the thinner the water tube, the greater the number of turns of the spiral tube body in a limited space within the can body, and the larger the heat transfer area of the entire water tube. Therefore, in the latent heat recovery type heat exchanger as in the prior art, it is more desirable to reduce the tube. However, when the water pipe is made narrower in this way, it becomes difficult to drain water from the water pipe. More specifically, for example, when the hot water apparatus is not used for a long period of time in the cold season, the water pipe may be drained for the purpose of preventing freezing in the water pipe. This draining operation is performed, for example, by stopping water supply to the water pipe and allowing the water in the water pipe to flow to the header side connected to the lower end thereof. In this case, if the water pipe is thin and its diameter is small, a water film is stretched at the opening at the lower end of the water pipe due to the surface tension of the water, making it difficult for water to flow into the header from this opening Produce. When such a phenomenon occurs, water remains in the vicinity of the lower end of the water pipe. When the inclination of the spiral tube body is gentle, such a phenomenon is more likely to occur, and the amount of residual water increases. This may cause the water to freeze in the water pipe and damage the water pipe.

  As another example of the conventional heat exchanger, there is one described in Patent Document 4. The heat exchanger described in the document includes a plurality of water pipe spiral tube portions housed in a can body, and the lower ends of the spiral tube body portions extend in the vertical direction. It has the structure connected to the header via. According to such a configuration, since the auxiliary pipe part extending in the vertical direction is connected to the lower end of each helical pipe part, even if the plurality of water pipes are temporarily narrowed, It is possible to make it difficult to form a water film at the lower end opening of the auxiliary tube portion. However, in the thing described in the same literature, since the auxiliary tube part extended in the vertical direction is directly connected to the lower end of the spiral tube part, it is difficult to arrange the header outside the side of the can, for example. It is. The one described in the same document must house the header inside the can body, but with such a configuration, the can body becomes larger, and thus the overall heat exchanger becomes larger and the weight increases. Invite. Further, since the water pipe and the header connected to each other are incorporated in the can body, the manufacturing work is complicated and the cost is high.

JP-A-2005-321170 JP 2005-321171 A JP 2005-321172 A U.S. Pat. No. 4,313,491

  The present invention has been conceived under such circumstances, and it is difficult to drain water from a water pipe when the water pipe having a helical tube portion is thinned. It is an object of the present invention to provide a heat exchanger that can be appropriately prevented 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 can body having a peripheral wall portion, a spiral tube body portion having a central axis extending in the vertical direction and disposed in the can body, and the A water pipe for heat exchange having an auxiliary pipe part that is connected to the lower end of the helical pipe part and penetrates the peripheral wall part of the can body and protrudes toward the outside of the can body, and the can body A heat exchanger provided outside and connected to a front end of the auxiliary pipe body, and a heat exchanger, wherein the can body of the auxiliary pipe body The portion protruding to the outside of the auxiliary tube body is characterized in that a bent portion that is bent so that the height of the portion closer to the tip of the auxiliary tube portion is lower is formed.

  According to such a configuration, the presence of the bent portion of the auxiliary tube body portion causes a difference in height between the lower end of the spiral tube portion and the lower end tip portion of the auxiliary tube portion, and exists in the bent portion. It is possible to apply the water head pressure of the water to be applied to the distal end portion of the auxiliary tube portion. Therefore, in the case where the water pipe is thinned, when draining the water pipe, the water head pressure prevents the water film from being stretched at the tip opening of the auxiliary pipe body, and the water in the water pipe Can be appropriately discharged from the tip opening portion into the header. As a result, it is possible to appropriately avoid the problem that the residual water that could not be removed from the water pipe is frozen and the water pipe is damaged. In addition, as an important effect, in the present invention, since the header is arranged outside the can body, unlike the structure in which both the header and the helical tube body portion are arranged in the can body, the whole This is suitable for reducing the size of the apparatus. Furthermore, since the bent part of the auxiliary tube part is located outside the tube body, it is easy to form the bent part, and it is possible to appropriately avoid problems such as a significant increase in manufacturing cost.

  In a preferred embodiment of the present invention, a plurality of the water pipes are provided, and the spiral tubular body portions of the plurality of water pipes are arranged in a substantially concentric overlapping shape, and the header includes the plurality of water pipes. The plurality of water pipes with respect to the header have a configuration in which a space part communicating with the inside of the auxiliary pipe part of the water pipe is formed inside, and an opening for connecting a pipe body communicating with the space part is provided. As for the connection, the tip of the auxiliary tube portion is positioned closer to the opening as the water tube has a shorter overall length.

  According to such a configuration, when the water in the plurality of water pipes flows into the space part in the header and then is discharged from the header connection opening of the header to the outside of the header, as described below. Thus, it is possible to prevent the air from being accumulated in the space and appropriately perform drainage using the siphon phenomenon. That is, when draining water by flowing water from the inside of each of the plurality of water pipes into the space in the header, the water pipe having a shorter dimensional length is completed earlier. On the other hand, the auxiliary pipe part of the water pipe that completes draining earlier is closer to the opening for connecting the pipe of the header, and the auxiliary pipe part of the water pipe that finishes draining later is the opening part. Far away from. For this reason, even after the drainage of the water pipe closest to the opening is completed, the inflow of water from the auxiliary tube part farthest from the opening into the space of the header is continued. Therefore, until all the water pipes have been drained, water can be filled over a wide area in the space portion of the header, and air can be prevented from collecting in the space portion. If the occurrence of air pockets can be prevented in this way, drainage from a plurality of water pipes can be promoted using a siphon phenomenon.

  In a preferred embodiment of the present invention, the auxiliary tube portion has a straight tube portion that is positioned closer to the spiral tube portion than the bent portion and extends in a substantially horizontal direction, and the bent portion The part is formed by connecting a bend pipe to the straight pipe part, and the peripheral wall part of the can body surrounds the periphery of the spiral pipe body part, and a part thereof is connected to the straight pipe part. A first member provided with a notch for avoiding interference and a through hole through which the straight pipe part of the auxiliary pipe part is inserted are formed, and the first part is closed so as to close the notch. And a second member joined to the first member.

  According to such a configuration, the following method can be employed in manufacturing the heat exchanger. That is, first, the outer periphery of the spiral tube portion is surrounded by the first member of the can body. At that time, by arranging the straight tube portion of the auxiliary tube portion at the location where the cutout portion of the first member of the can body is formed, interference between the first member and the straight tube portion can be avoided. . Then, the 2nd member of a can is joined to the 1st member, and the notch part of this 1st member is plugged up. However, at that time, the straight tube portion of the auxiliary tube portion is inserted through the through hole of the second member. By such a process, the spiral tube body portion is accommodated in the can body, and a part of the straight tube portion connected to the spiral tube body portion penetrates the peripheral wall portion of the can body to the outside of the can body. A projecting configuration is obtained. Thereafter, a bend pipe is connected to the straight pipe portion outside the can body. Through such a series of steps, it becomes possible to manufacture a heat exchanger having a configuration intended by the present invention, and the manufacturing work becomes easy.

  In a preferred embodiment of the present invention, the lowermost portion of the helical tube portion has a larger tube inclination angle than other portions above it.

  According to such a configuration, it is possible to increase the water head pressure of water existing in the portion where the tube inclination angle near the lower end of the spiral tube portion is increased. Therefore, at the time of draining water from the water pipe, a water film is less likely to be generated at the tip opening of the auxiliary pipe body due to the action of the water head pressure, and drainage is further promoted.

  The heat exchanger provided by the second aspect of the present invention includes a can body having a peripheral wall portion, a spiral tube body portion having a central axis extending in the vertical direction and disposed in the can body, and this A water pipe for heat exchange having an auxiliary pipe part that is connected to the lower end of the helical pipe part and penetrates the peripheral wall part of the can body and protrudes toward the outside of the can body, and the can body A heat exchanger including a header for water entry or hot water that is arranged outside and connected to a distal end portion of the auxiliary tube body portion, and is a portion closer to the lowermost end of the spiral tube body portion Is characterized in that the tube inclination angle is made larger than that of other portions above it.

  According to such a configuration, it is possible to increase the water head pressure existing in the portion near the lower end of the spiral tube portion. Therefore, unlike the heat exchanger provided by the first aspect of the present invention, even if the auxiliary tube body is not provided with a bent portion, the auxiliary tube body portion of the auxiliary tube body portion during drainage work is not provided. It is possible to appropriately perform the water draining operation so that the water film is not stretched at the tip opening.

  In a preferred embodiment of the present invention, the distal end portion of the auxiliary tubular body portion enters the inside of the header, and the distal end surface thereof has an axial length direction of the distal end portion of the auxiliary tubular body portion. An oblique cut portion inclined with respect to the surface is formed.

  According to such a structure, the opening area of the front-end | tip part of an auxiliary tube part becomes large, and it can be made hard to produce the water film resulting from the surface tension of water in this part.

  The hot water apparatus provided by the third aspect of the present invention includes the heat exchanger provided by the first or second aspect of the present invention.

  According to such a configuration, the same effect as described for the heat exchanger provided by the first or second 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.

  FIGS. 1-8 has shown the hot water supply apparatus as a specific example of the hot water apparatus with which this invention was applied, and the structure relevant to this. As clearly shown in FIG. 1, the hot water supply apparatus A of this embodiment includes a combustor 1, a heat exchanger B, a bottom casing 80, and an exhaust duct 81.

  The combustor 1 is of a reverse combustion type in which fuel oil such as kerosene or light oil is sprayed downward by a spray nozzle 14 and burned. The sprayed fuel sprayed from the spray nozzle 14 is mixed with combustion air in the burner cylinder 11 and then discharged downward to burn. The combustor 1 is covered and supported by a can body 10 mounted on the heat exchanger B, and fuel is supplied from the outside of the can body 10 via a pipe 12. . A blower fan 13 for supplying combustion air to the combustor 1 and a motor M that drives the blower fan 13 are provided on the upper portion of the can body 10.

  The heat exchanger B includes a can body 2, a plurality of water pipes 4, a pair of headers 5 </ b> A and 5 </ b> B for incoming and outgoing hot water, and a partition member 6.

  The can body 2 has a substantially cylindrical peripheral wall portion 20 and a pair of cover bodies 21A and 21B attached to the upper and lower portions of the peripheral wall portion 20, and is placed on the bottom casing 80. . The cover body 21A forms an opening 22A into which the lower part of the burner cylinder 11 enters. The cover body 21 </ b> B forms an opening 22 </ b> B for guiding the combustion gas after heat recovery by the plurality of water tubes 4 into the bottom casing 80. The can 2 is made of stainless steel, for example, and is not easily corroded due to a drain generated when latent heat is recovered from the combustion gas using the water pipe 4. In general, the drain generated with the recovery of latent heat from the combustion gas is strongly acidic, such as PH3, which has absorbed sulfur oxides, nitrogen oxides, and the like in the combustion gases. For this reason, the can 2 is made of a material excellent in acid resistance. In this respect, the plurality of water tubes 4 are the same, and the material thereof is, for example, stainless steel.

  The plurality of water tubes 4 include a helical tube portion 40 disposed in the can 2 and auxiliary tube portions 41A and 41B connected to the lower and upper ends of the helical tube portion 40. The plurality of helical tube portions 40 has a configuration in which the central axis extends in the vertical direction, and a plurality of loop portions 40a having a hollow circular shape in plan view are stacked and connected in a plurality of stages in the vertical height direction. is doing. However, these spiral tubular body portions 40 have different winding diameters and are arranged in a substantially concentric overlapping winding shape. In the present embodiment, the pipe diameters of the plurality of water pipes 4 are the same, but the pipe diameters may be different. A space 3 is formed inward of the plurality of helical tube portions 40. A combustion gas passage 32 surrounded by the peripheral wall portion 20 of the can body 2 is formed on the outer periphery of the plurality of helical tube portions 40.

  Between each of the loop portions 40a adjacent to each other in the vertical direction of the plurality of spiral tubular body portions 40, a combustion gas passage gap 31 is formed to allow the space portion 3 and the combustion gas passage 32 to communicate with each other. Each gap 31 has spacers (not shown) inserted in a portion between the loop portions 40a, or presses a plurality of locations of each loop portion 40a so that the thickness in the vertical direction of the portion is larger than that of other portions. In addition, it is possible to define the desired dimensions by bringing the portions whose thicknesses in the vertical direction are increased and abutting each other.

  The pair of headers 5 </ b> A and 5 </ b> B are connected to the lower ends and the upper ends of the plurality of water pipes 4. A water supply pipe (not shown) is connected to the header 5 </ b> A, and water such as tap water supplied from the water supply pipe is supplied into the plurality of water pipes 4. A hot water pipe (not shown) is connected to the header 5B, and hot water heated through the plurality of water pipes 4 is sent to a desired hot water supply destination through the hot water pipe. From the viewpoint of improving the water drainability from the plurality of water pipes 4, there is no need to devise in particular for the header 5 </ b> B and the auxiliary pipe part 41 </ b> B. The header 5B is connected to the tip. On the other hand, as for the header 5A and the lower auxiliary pipe portion 41A connected to the header 5A, means for improving water drainage is provided as will be described later.

  The auxiliary pipe part 41A of each water pipe 4 includes a straight pipe part 410 extending from the lower end of each helical pipe part 40 in the tangential direction of each loop part 40a, and a bent part connected to the tip of the straight pipe part 410. 411. The straight pipe part 410 is formed integrally with the helical pipe part 40, for example, and penetrates the peripheral wall part 20 of the can body 2. The bending portion 411 is configured by connecting a separate bend pipe to the straight pipe portion 410, for example, and is bent downward so that the height is lower toward the tip end portion. A header 5 </ b> A is connected to the tip of the bent portion 411.

  As shown in FIGS. 3 and 4, the members constituting the peripheral wall portion 20 of the can body 2 include first and second members 20 </ b> A and 20 </ b> B. The first member 20A is formed by rounding a relatively thin, substantially rectangular stainless steel plate having flexibility into a cylindrical shape, and by joining both end edges 200a and 200b thereof, It is formed in a cylindrical shape. As clearly shown in FIG. 5, the first member 20A is formed with a notch 201 for avoiding interference with the auxiliary tube portion 41A and projecting a part thereof to the outside. Yes. The second member 20B is joined to the first member 20A so as to close the notch 201, and is made of a stainless steel plate that is thicker than the first member 20A. A plurality of through-holes 202 through which the straight pipe portion 410 is inserted are formed in the second member 20B. The first member 20A is also formed with a notch 201 ′ for avoiding interference with the upper auxiliary tube portion 41B. The notch 201 ′ is formed by the auxiliary tube portion 41B. A plurality of through-holes 202 ′ to be inserted are closed by a second member 20B ′ having a hole.

  The heat exchanger B having such a configuration can be easily manufactured through the following steps. That is, first, in a state where the bent portion 411 is not connected to the straight tube portion 410, the first member 20A surrounds the periphery of the plurality of spiral tube portions 40. At that time, the straight pipe part 410 of the lower auxiliary pipe part 41A is inserted into the notch part 201, and the upper auxiliary pipe part 41B is arranged to pass through the notch part 201 ′, thereby Interference can be avoided. Next, the second members 20B and 20B ′ are joined to the first member 20A to close the notches 201 and 201 ′. At that time, the straight pipe part 410 and the upper auxiliary pipe part 41B are inserted into the through holes 202 and 202 'of the second members 20B and 20B'. Thereafter, the bend pipe is connected to the straight pipe section 410 and the bending section 411 is provided. The header 5A may be connected to the bent portion 411 after that or before that. In this heat exchanger B, since the auxiliary pipe portions 41A and 41B are supported through the relatively thick second members 20B and 20B ′, their fixed holding strength is increased. It can be increased. In addition, according to the above configuration, the second member 20B, 20B ′ through which the auxiliary tube portions 41A, 41B penetrates the notches 201, 201 ′, and therefore the combustion gas in the can body 2 Is easily prevented from leaking out of the can 2.

  In addition, when connecting the bending part 411 to 41 A of auxiliary tube parts, the following means can be employ | adopted. That is, as shown in FIG. 4, a flared portion 411a is formed at one end of the bent portion 411 of the auxiliary tube portion 41A, and the distal end portion of the straight pipe portion 410 is fitted therein, and these Is brazed. In this operation, if a brazing material such as silver brazing is filled in the flare processing portion 411a, a gap generated between the inner peripheral surface of the flare processing portion 411a and the front end portion of the straight pipe portion 410 is formed by the brazing material. It can be mitigated. This is preferable in aligning the inner diameter of the connection portion between the bent portion 411 and the straight pipe portion 410 with the inner diameter of the other portion.

  As shown in FIG. 6, the header 5 </ b> A has a cylindrical portion 50 whose axial length direction is substantially horizontal, and the inside thereof is a space portion 51 whose one end in the axial length direction is closed. At the other end of the space 51, an opening 52 for connecting a pipe connected to a water supply pipe (not shown) is formed. The structure of the header 5B is the same as that of the header 5A. The front end portions 412 of the plurality of auxiliary tube portions 41A (the front end portions of the bent portions 411) penetrate the peripheral wall portion of the cylindrical portion 50 from the upper side to the lower side, and enter the space portion 51 in a state where the header 5A is entered. It is connected to. The plurality of auxiliary tube portions 41A are arranged in the axial direction of the cylindrical portion 50, and the arrangement of the auxiliary tube portions 41A is closer to the opening 52 in the water tube 4 having a shorter dimensional length. More specifically, the water pipe 4 having the spiral tube body portion 40 having the smallest winding diameter and the innermost circumference has the shortest dimensional length, and the auxiliary tube portion 41A of the water pipe 4 (at the right end in FIG. 6). The auxiliary tube portion 41 </ b> A) is disposed closest to the opening 52. On the contrary, the water pipe 4 having the spiral tube body portion 40 having the largest winding diameter and located on the outermost circumference has the longest dimensional length, and the auxiliary tube portion 41A of the water tube 4 (the auxiliary tube portion at the left end in FIG. 6). 41A) is arranged farthest from the opening 52.

  The header 5A and each auxiliary pipe part 41A are joined by welding or brazing, and the joined part w1 is located on the inner side of the header 5A. Since the plurality of auxiliary tube portions 41A stand side by side above the outer peripheral surface of the header 5A, when the interval s1 between the plurality of auxiliary tube portions 41A is small, the gap portions thereof It is difficult to perform welding or the like. As a means for solving this problem, in the present embodiment, the joint portion w1 is provided inside the header 5A. As means for realizing this, the tubular portion 50 of the header 5A is configured by joining upper and lower members 50a and 50b. According to such a configuration, when connecting the plurality of auxiliary tube portions 41A to the upper member 50a, as shown in FIGS. 7A and 7B, the lower member is connected to the upper member 50a. It can be set as the state which 50b is not joined. In such a state, the inner peripheral surface of the upper member 50a becomes an open surface that is not covered by the lower member 50b, and the outer peripheral surface of each auxiliary tube portion 41A is appropriately welded to the open surface. It becomes possible to braze. After the joining of the upper member 50a and each auxiliary tube portion 41A is completed, the upper and lower members 50a and 50b may be joined together.

  As shown in FIG. 6, the non-opening end 59 located on the opposite side of the opening 52 of the header 5A can be configured to include a curved wall that swells in a substantially hemispherical shape. . This portion is also formed by the upper and lower members 50a and 50b. According to such a configuration, it is not necessary to use a member different from the upper and lower members 50a and 50b as means for closing the end portion 59, and the number of parts of the header 5A and the number of assembly steps can be reduced. Can be reduced. Of course, even when the end portion 59 is configured as described above, each of the upper and lower members 50a and 50b can be easily formed by, for example, pressing. Moreover, if the wall part of the end part 59 is made into the above-mentioned curved surface shape, compared with the case where it forms in planar shape, the advantage used as a structure strong against water hammer is also acquired.

  An oblique cut portion 413 that is inclined with respect to the axial length direction of the distal end portion 412 is formed at the distal end portion 412 of each auxiliary tube portion 41A. The oblique cut portion 413 is a means for increasing the opening area of the tip portion 412 and making it difficult to form a water film during the water draining operation described later. The oblique cut portion 413 can be shaped as shown in FIG. 8, for example. Further, the oblique cut portion 413 can be formed in a curved shape in place of the cut line shape in a straight line shape. For the upper auxiliary tube portion 41B, it is not necessary to provide the oblique cut portion 413 as described above.

  The partition member 6 is made of, for example, stainless steel, and as shown in FIG. 2, the partition member 6 is formed in a bowl shape or a concave dish shape in which the upper surface portion is recessed, and the upper surface is covered with a heat insulating material 68 such as ceramic fiber. It has a broken main body 60 and a flange 61 connected to the outer periphery of the upper portion of the main body 60. The partition member 6 is attached to the plurality of spiral tubular body portions 40 using the flange portions 61 and closes the intermediate portion in the vertical direction of the space portion 3. As a result, the space 3 is partitioned into the first and second regions 30a and 30b. Further, the plurality of helical tube portions 40 are divided into first and second heat exchange portions HT1 and HT2 that surround the first and second regions 30a and 30b, respectively. If the partition member 6 has a bowl shape or a concave dish shape as described above, there is an advantage that the volume of the first region 30a that also serves as a combustion chamber can be increased.

  Of the bottom portion of the can body 2, a portion between the lower portion of the peripheral wall portion 20 and the annular wall 221 of the cover body 21 </ b> B is a drain for receiving a drain dripping from the water pipe 4 as latent heat is recovered from the combustion gas. It is a receiving part 26. The drain receiving portion 26 is provided with a drain outlet 26a, and as shown in FIG. 1, the drain is discharged to the outside through a pipe 26b connected to the outlet 26a. Has been.

  The bottom casing 80 has a substantially rectangular parallelepiped box shape with a hollow inside, and the heat exchanger B and the exhaust duct 81 are placed on the bottom casing 80 so as to be aligned. The combustion gas that has passed through the can 2 of the heat exchanger B flows downward into the bottom casing 80 from the opening 80a, and then upwards from the other opening 80b to the bottom opening of the exhaust duct 81. Is going to progress. The combustion gas flowing into the exhaust duct 81 is then discharged to the outside as exhaust gas from the exhaust port 81a.

  Next, the operation of the hot water supply apparatus A will be described.

  First, when water supply is started into the plurality of water pipes 4 via the header 5A, the combustor 1 is driven. By driving the combustor 1, combustion gas is supplied into the first region 30 a of the space portion 3, and the combustion gas travels downward and collides with the upper surface portion of the partition member 6, and below it. Progress is prevented. Then, the combustion gas passes through the plurality of gaps 31 of the first heat exchanging part HT1 and enters the combustion gas passage 32 while circulating along a fixed path in the first region 30a as shown by the arrow in the drawing. Inflow. In this process, sensible heat can be recovered from the combustion gas by the first heat exchanging unit HT1. Next, after the combustion gas travels downward in the combustion gas passage 32, it passes through the plurality of gaps 31 of the second heat exchange part HT2 and flows into the second region 30b. In this process, latent heat can be recovered from the combustion gas by the second heat exchange unit HT2. If sensible heat and latent heat are recovered from the combustion gas in this way, the heat exchange efficiency can be increased. Hot water generated by heat exchange when passing through the plurality of water pipes 4 is supplied to a desired hot water supply destination via the header 5B. In the second heat exchanging unit HT2, the drain generated along with the latent heat recovery is received by the drain receiving unit 26 and then discharged to the outside through the discharge port 26a and the pipe 26b.

  When the above-described hot water supply device A is not used for a long time in the cold season, water supply to the header 5A is stopped, and water in the plurality of water tubes 4 is directed to the header 5A side for the purpose of preventing freezing in the plurality of water tubes 4. Drain and drain. On the other hand, a bent portion 411 is formed in the lower auxiliary tube portion 41A, and the tip opening portion of the auxiliary tube portion 41A is lower than the lower end of the spiral tube portion 40 by an appropriate height H. ing. Therefore, even when each water pipe 4 is made thin, due to the action of the water head pressure existing in the bent portion 411, a water film is not generated at the tip opening of the auxiliary pipe portion 41A. Water in the plurality of water pipes 4 can be appropriately discharged toward the header 5A. The height H is preferably in a relationship of H> 15 / R, where R is the diameter of the auxiliary tube portion 41A. When the above equation is satisfied, it is possible to break the water film generated by the surface tension at the tip opening of the auxiliary tube portion 41A by the water head pressure at the height H. Since the oblique cut portion 413 is formed at the tip of the auxiliary tube portion 41A and the opening area of the tip opening is increased, it is possible to make the water film less likely to occur.

  In addition, in the hot water supply apparatus A, during the period in which the water pipes 4 are drained, the space 51 of the header 5A is filled with water, and a smooth drainage operation using the siphon phenomenon is possible. Become. That is, when water is drained from each of the plurality of water pipes 4, the water pipe 4 having a shorter dimensional length completes draining earlier, and finally drains from the water pipe 4 having the longest dimensional length. On the other hand, since the auxiliary pipe part 41A is closer to the pipe connection opening 52 of the header 5A as the water pipe 4 completes draining earlier, draining from the shortest water pipe 4 is completed, for example. Even after, water flows into the space 51 of the header 5A from the auxiliary pipe body 41A of the other water pipe 4 located further away from the opening 52. For this reason, substantially the entire interior of the space 51 is filled with water, and the accumulation of air in the space 51 is suppressed. Unlike the present embodiment, the auxiliary pipe body portion 41A of the shortest water pipe 4 is arranged at the position farthest from the opening 52. When drainage from the water pipe 4 is finished, Of these, water will no longer flow in the vicinity of the auxiliary pipe part 41A of the water pipe 4, and an air pocket will be produced in this part. According to the present embodiment, by preventing the occurrence of such air pockets, drainage from the plurality of water pipes 4 can be promoted using the siphon phenomenon.

  As described above, in this hot water supply apparatus A, water can be drained from each water pipe 4 appropriately. Therefore, it is possible to prevent an accident in which the water pipe 4 is damaged due to freezing of residual water in each water pipe 4 during the cold season. In addition, since the headers 5A and 5B are both arranged outside the can body 2, for example, unlike the case where the headers 5A and 5B are arranged in the can body 2, the overall size can be reduced. Preferred. Further, since the bent portion 411 of the auxiliary tube body portion 41A is also located outside the can body 2, the formation of the bent portion 411 is easy, and a problem such as a significant increase in manufacturing cost can be avoided appropriately. Is done.

  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 embodiment shown in FIG. 9, the coiled tube portion 40 of the water tube 4 is configured using a flat tube. According to such a configuration, the gap 31 formed between the flat tubes has an elongated shape in the passage direction of the combustion gas, and the coiled tube portion 40 and the combustion when the combustion gas passes through the gap 31 It is possible to increase the degree of contact with the gas. Therefore, the effect which can improve heat exchange efficiency similarly to the case where a plurality of coiled tube parts are provided in the form of lap winding is acquired. Even when there is only one water pipe 4, if the diameter of the water pipe 4 is small, it may still be difficult to drain the water. Therefore, the present invention can also be suitably applied to a heat exchanger having only one water pipe 4 as described above. In addition, when making the water pipe 4 into one, the water pipe 4 can also be formed using a round pipe.

  In the embodiment shown in FIG. 10, the tube inclination angle α1 (the inclination angle with respect to the horizontal direction of the one or more loop portions 40a located near the lowermost end of the helical tube portion of each water tube 4 is the following α2 And the tube inclination angle α2 of the auxiliary tube portion 41A is larger than the tube inclination angle of other portions of the spiral tube portion 40. The angles α1 and α2 may be the same or non-identical. According to this embodiment, it is possible to increase the water head pressure of the water present in the portions defined as the tube inclination angles α1 and α2. Therefore, at the time of draining water from the water pipe 4, it becomes difficult to generate a water film at the tip opening of the auxiliary pipe body 41A due to the action of the water head pressure, and it is possible to appropriately perform the draining operation.

  In the embodiment shown in FIG. 10, it is not necessary to provide means corresponding to the bent portion 411 in the auxiliary tube portion 41A. However, if a means corresponding to the bending portion 411 is provided, it is possible to further increase the water head pressure acting on the tip portion of the auxiliary tube portion 41A and further facilitate the smoothing of the water draining operation. It does not matter as a simple configuration.

  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 heat exchanger according to the present invention, from the viewpoint of improving the heat exchange efficiency, the helical tube portion of the water tube is divided into first and second heat exchange portions so that sensible heat and latent heat can be recovered. However, the present invention is not limited to this. It can also be configured as a heat exchanger of a type in which the spiral tube part is not divided into two heat exchange parts.

  The spiral tubular body portion and the auxiliary tubular body portion of the water tube may be integrated or separated. The bending portion of the auxiliary tube portion may be formed integrally with the spiral tube portion without using a bend tube separate from the spiral tube portion, for example. The spiral tubular body portion of the water tube is not limited to a circular loop shape, and may have other shapes such as a rectangular loop shape. The can can also be formed into a rectangular cylinder, for example, corresponding to the shape of each helical tube. As the combustor, a gas combustor or the like may be used in addition to the oil combustor. The combustion method of the combustor may be a normal combustion method in which, for example, the combustion gas advances upward instead of the reverse combustion method in which the combustion gas advances downward of the combustor. The present invention can be applied to various types of heat exchangers that are provided such that the central axis of the helical tube portion of the water pipe extends in the vertical direction.

  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. Includes a device for producing hot water.

It is a schematic sectional drawing which shows an example of the hot water supply apparatus with which this invention was applied. It is principal part sectional drawing of the hot-water supply apparatus shown in FIG. It is sectional drawing which looked at FIG. 2 from the bottom face side. It is a principal part expanded sectional view of FIG. It is a schematic exploded perspective view of the heat exchanger which comprises the hot water supply apparatus shown in FIG. It is principal part sectional drawing which shows the structure of the connection part of the header for water intake of the hot water supply apparatus shown in FIG. 1, and a water pipe. (A) is principal part exploded sectional drawing of the connection structure shown in FIG. 6, (b) is side sectional drawing of (a). It is a principal part side view which shows the other example of the front-end | tip part shape of the auxiliary tube part of a water pipe. It is principal part sectional drawing which shows the other example of the hot water supply apparatus with which this invention was applied. It is principal part sectional drawing which shows the other example of the hot water supply apparatus with which this invention was applied.

Explanation of symbols

A Hot water supply device (hot water device)
B heat exchanger 1 combustor 2 can body (for heat exchanger)
4 Water pipe 5A Header 40 Spiral tube part 40a Loop part 41A Auxiliary pipe part 410 Straight pipe part (of the auxiliary pipe part)
411 Bending part (of auxiliary tube part)
413 Diagonal cut part

Claims (7)

A can having a peripheral wall,
The can body that has a central axis extending in the vertical direction and is connected to the lower end of the helical tube portion disposed in the can body, and penetrates the peripheral wall portion of the can body. A water pipe for heat exchange having an auxiliary pipe body part protruding from the outside of the tip,
A header for water entry or hot water that is arranged outside the can body and connected to the tip of the auxiliary pipe body part; and
A heat exchanger comprising:
Of the auxiliary tube portion, a bent portion is formed at a portion protruding to the outside of the can body so as to be bent so that the height of the portion closer to the tip of the auxiliary tube portion is lower. And a heat exchanger. A plurality of the water pipes are provided, and the spiral tubular body portions of the plurality of water pipes are arranged in a substantially concentric overlapping winding shape,
The header has a configuration in which a space portion communicating with the auxiliary tube body portion of the plurality of water pipes is formed inside, and an opening for connecting a tube body communicating with the space portion is provided.
The heat exchanger according to claim 1, wherein the plurality of water pipes are connected to the header such that the tip of the auxiliary pipe body portion is located closer to the opening as the water pipe has a shorter overall length. The auxiliary tube portion has a straight tube portion that is positioned closer to the spiral tube portion than the bent portion and extends in a substantially horizontal direction, and the bent portion is bent to the straight tube portion. Is formed by connecting
The peripheral wall portion of the can body surrounds the periphery of the helical tube body portion, and a first member provided with a notch portion for avoiding interference with the straight tube portion in a part thereof; A through-hole through which the straight tube portion of the auxiliary tube portion is inserted is formed, and a second member joined to the first member so as to close the notch portion is provided. The heat exchanger according to claim 1 or 2.   The heat exchanger according to any one of claims 1 to 3, wherein a portion closer to the lowermost end of the spiral tubular body portion has a tubular body inclination angle larger than other portions above it. A can having a peripheral wall,
The can body that has a central axis extending in the vertical direction and is connected to the lower end of the helical tube portion disposed in the can body, and penetrates the peripheral wall portion of the can body. A water pipe for heat exchange having an auxiliary pipe body part protruding from the outside of the tip,
A header for water entry or hot water that is arranged outside the can body and connected to the tip of the auxiliary pipe body part; and
A heat exchanger comprising:
The heat exchanger according to claim 1, wherein a portion closer to the lowermost end of the helical tube portion has a larger tube inclination angle than other portions above it.   The distal end portion of the auxiliary tubular body portion enters the inside of the header, and an oblique cut portion inclined with respect to the axial length direction of the distal end portion of the auxiliary tubular body portion is formed on the distal end surface. The heat exchanger according to any one of claims 1 to 5.   A hot water apparatus comprising the heat exchanger according to any one of claims 1 to 6.

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