JP2017150749A - Heat exchanger and combustion apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger which can improve efficiency for transmitting a calorie of a combustion gas to a heat transfer pipe, and a combustion apparatus having the same.SOLUTION: A heat exchanger comprises a plurality of fins 51 and heat transfer pipes 52. A plurality of the fins 51 have a plurality of through-holes H which are arranged side by side along a first direction D1 on a main surface S. The heat transfer pipes 52 pass through the inside of a plurality of the through-holes of a plurality of the fins 51. A plurality of the through-holes H include even-numbered first stage through-holes H1 and even-numbered second stage through-holes H2. The even-numbered first stage through-holes H1 are arranged at an upstream side in a flow direction of a combustion gas rather than the even-numbered second stage through-holes H2 in a second direction D2. The number of the even-numbered first stage through-holes H1 is larger than the number of the even numbered second stage through-holes H2. Each of the even-numbered second stage through-holes H2 is arranged so as to be displaced from each of the even numbered first stage through-holes H1 in the first direction D1.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a heat exchanger and a combustion apparatus, and more particularly to a heat exchanger for recovering heat of combustion gas and a combustion apparatus including the heat exchanger.

  Conventionally, a combustion apparatus including a fin-and-tube heat exchanger has been used. This fin-and-tube heat exchanger is described in, for example, Japanese Patent Publication No. 6-86995 (Patent Document 1). The heat exchanger described in this publication includes a fin group and a plurality of rows of heat transfer tube groups inserted into the fin group. The plurality of heat transfer tube groups include a first heat transfer tube group that is an air inflow side row and a second heat transfer tube group that is an air outflow side row. The heat transfer tubes of the first row of heat transfer tube groups and the second row of heat transfer tube groups are arranged side by side along the first direction. The heat transfer tube group in the second row is arranged with a space in the second direction intersecting the first direction with the heat transfer tube group in the first row. The heat transfer tubes of the second row of heat transfer tube groups are arranged in the second direction so as to be shifted from the heat transfer tubes of the first row of heat transfer tube groups in the first direction. Specifically, the heat transfer tube group in the first row includes six heat transfer tubes, and the heat transfer tube group in the second row includes eight heat transfer tubes.

Japanese Patent Publication No. 6-86995

  Since the temperature of the combustion gas is higher on the upstream side in the flow direction of the combustion gas than on the downstream side, the amount of heat of the combustion gas can be transmitted to the heat transfer tube more than that on the downstream side.

  However, in the heat exchanger described in the above publication, the number of heat transfer tubes included in the air inflow side column upstream of the combustion gas flow direction is equal to the air outflow side downstream of the combustion gas flow direction. Less than the number of heat transfer tubes in the column. For this reason, the calorie | heat amount of the combustion gas transmitted to a heat exchanger tube in the upstream of the flow direction of combustion gas decreases. For this reason, the efficiency with which the amount of heat of the combustion gas is transmitted to the heat transfer tube is lowered.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a heat exchanger capable of improving the efficiency with which the amount of heat of combustion gas is transmitted to a heat transfer tube, and a combustion apparatus including the heat exchanger. It is to be.

  The heat exchanger of the present invention is for recovering the heat of combustion gas. The heat exchanger includes a plurality of fins and a heat transfer tube. Each of the plurality of fins has a main surface and a plurality of through-holes arranged side by side along the first direction on the main surface, and is laminated and spaced from each other. The heat transfer tube passes through the plurality of through holes of each of the plurality of fins. The plurality of through-holes through which the heat transfer tubes pass include even-numbered first-stage through-holes and even-numbered second-stage through-holes. The even numbered first-stage through holes are arranged side by side in the first direction. The even-numbered second-stage through holes are arranged side by side in the first direction, and the even-numbered first-stage through holes are arranged at intervals in a second direction that intersects the first direction. Yes. The even-numbered first-stage through holes are arranged upstream of the even-numbered second-stage through holes in the second direction in the combustion gas flow direction. The number of even-numbered first-stage through holes is larger than the number of even-numbered second-stage through holes. Each of the even-numbered second-stage through holes is disposed so as to be shifted in the first direction from each of the even-numbered first-stage through holes.

  According to the heat exchanger of the present invention, the even-numbered first-stage through holes are arranged upstream of the even-numbered second-stage through holes in the second gas direction in the second direction. The number of even-numbered first-stage through holes is larger than the number of even-numbered second-stage through holes. For this reason, the amount of heat of the combustion gas that is transmitted to the heat transfer tubes that pass through the even-numbered second through holes on the upstream side in the flow direction of the combustion gas increases. For this reason, the efficiency by which the calorie | heat amount of combustion gas is transmitted to a heat exchanger tube can be improved. In addition, since the plurality of through holes include an even number of first-stage through holes and an even number of second-stage through holes, one end and the other end of the heat transfer tube passing through the plurality of through holes are used as the main surface. Can be placed on the side. Therefore, connection of piping to the heat transfer tube can be facilitated. Further, each of the even-numbered second-stage through holes is arranged so as to be shifted in the first direction from each of the even-numbered first-stage through holes. For this reason, combustion gas can be made easy to flow to the circumference of a heat exchanger tube which passes through each of even-numbered 2nd stage through-holes. Therefore, the heat quantity of the combustion gas can be efficiently transmitted to the heat transfer tubes passing through the even-numbered second stage through holes.

  In the above heat exchanger, the pitch of the even numbered second stage through holes is larger than the pitch of the even numbered first stage through holes. The even numbered first stage through holes arranged at both ends in the first direction are outside in the first direction than the even numbered second stage through holes arranged at both ends in the first direction. Respectively. For this reason, each of the even-numbered second-stage through holes can be shifted from each of the even-numbered first-stage through holes in the first direction. In addition, the combustion gas can easily flow outside each of the even-numbered second-stage through holes arranged at both ends in the first direction. Thereby, the efficiency with which the calorie | heat amount of combustion gas is transmitted to the heat exchanger tube which passes the 2nd step | paragraph through-hole of an even number can be improved.

  In the above heat exchanger, the distance between any of the even-numbered first-stage through holes and the even-numbered second-stage through-holes through which the heat transfer tubes continuously pass is equal to the even-numbered first-stage through-holes. It is equal to either the pitch or the pitch of the even numbered second stage through holes. Therefore, the bent portion of the heat transfer tube connecting the heat transfer tubes passing through the adjacent first-stage through holes among the even-numbered first-stage through holes and the adjacent second of the even-numbered second-stage through holes. One of the bent portions of the heat transfer tubes connecting the heat transfer tubes passing through the step through holes, one of the even numbered first step through holes through which the heat transfer tubes pass continuously, and any of the even numbered second step through holes. The bent portion of the heat transfer tube that passes continuously can have the same shape. Thereby, productivity of a heat exchanger can be improved.

  In the above heat exchanger, the even-numbered first-stage through holes and the even-numbered second-stage through holes have symmetrical axes passing through the centers of the plurality of fins in the first direction in the second direction. They are arranged symmetrically with respect to the line. Therefore, the combustion gas can be brought into contact with the heat transfer tubes passing through the even-numbered first-stage through holes and the even-numbered second-stage through holes arranged symmetrically with respect to the symmetry axis. Therefore, the heat quantity of the combustion gas can be transmitted to the heat transfer tube evenly with respect to the symmetry axis. Thereby, the efficiency by which the calorie | heat amount of combustion gas is transmitted to a heat exchanger tube can be improved.

  In the above heat exchanger, at least one of the plurality of fins includes a cut-and-raised slit having a tunnel-like hole protruding from the main surface and extending in the second direction. The cut-and-raised slit is disposed in a region adjacent to at least one of the plurality of second-stage through holes in the first direction. For this reason, the flow of the combustion gas is divided into the combustion gas flowing in the tunnel-shaped hole of the cut and raised slit and the combustion gas flowing outside the tunnel-shaped hole. Thereby, since the turbulent flow can be generated in the flow of the combustion gas, it is possible to improve the efficiency in which the heat amount of the combustion gas is transmitted to the heat transfer tube passing through at least one of the plurality of second stage through holes. .

  In the heat exchanger, at least one of the plurality of fins includes a cut-and-raised wall portion that protrudes from the main surface and extends in the first direction. The cut-and-raised wall portion is disposed on the opposite side of the even-numbered first-stage through holes with respect to the even-numbered second-stage through holes in the second direction, and at least one of the even-numbered second-stage through holes. Is shifted in the first direction. For this reason, the flow of the combustion gas flowing in the second direction can be cut up and changed in the first direction by the wall portion on the downstream side in the flow direction of the combustion gas from the even-numbered second stage through holes. Thereby, the efficiency by which the heat quantity of combustion gas is transmitted to the heat transfer tube passing through at least one of the even-numbered second stage through holes can be improved.

  In the above heat exchanger, at least one of the plurality of fins includes a protrusion protruding from the main surface. The convex portion is disposed on the even-numbered first-stage through hole side with respect to the even-numbered second-stage through-holes in the second direction, and from the at least one of the even-numbered first-stage through-holes in the first direction. It is shifted and arranged. For this reason, the flow of combustion gas can be changed by a convex part. Thereby, turbulent flow can be generated in the flow of the combustion gas flowing downstream through the periphery of the heat transfer tube passing through at least any of the even-numbered first-stage through holes. The efficiency transmitted to the heat transfer tube passing through at least one of the second-stage through holes can be improved.

  The combustion apparatus of the present invention includes the above heat exchanger and a burner for supplying combustion gas to the heat exchanger. According to the combustion apparatus of the present invention, the efficiency with which the amount of heat of the combustion gas supplied from the burner is transmitted to the heat transfer tube of the heat exchanger can be improved.

  As described above, according to the present invention, it is possible to provide a heat exchanger capable of improving the efficiency with which the amount of heat of combustion gas is transmitted to the heat transfer tube, and a combustion apparatus including the heat exchanger.

It is the schematic which shows the structure of the combustion apparatus in one embodiment of this invention. It is a perspective view which shows roughly the structure of the primary heat exchanger and can body in one embodiment of this invention. It is sectional drawing which follows the III-III line of FIG. It is a schematic perspective view which mainly shows the structure of the heat exchanger tube of the primary heat exchanger in one embodiment of this invention. It is a schematic top view which mainly shows the structure of the heat exchanger tube of the primary heat exchanger in one embodiment of this invention. It is a schematic sectional drawing which mainly shows the structure of the primary heat exchanger, the can body, and the exhaust gas collection cylinder in one embodiment of this invention. It is a perspective view which shows roughly the structure of the fin of the primary heat exchanger in one embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, the structure of the combustion apparatus in one embodiment of the present invention will be described.

  Referring to FIGS. 1 and 2, combustion apparatus 1 of the present embodiment is a latent heat recovery type heat source machine that can recover the latent heat of combustion gas. The combustion apparatus 1 includes a housing 2, a burner 3, a burner case 3a, a blower 4, a primary heat exchanger (heat exchanger) 5, a can 5a, a secondary heat exchanger 6, and a secondary Heat exchanger case 6a, exhaust collecting cylinder 7, silencer 8, neutralizer 9, pipe 10, water supply pipe 11, water inlet 11a, hot water supply pipe 12, hot water outlet 12a, and drain pipe 20 And has mainly.

  In the housing 2, a burner 3, a burner case 3a, a blower 4, a primary heat exchanger 5, a can 5a, a secondary heat exchanger 6, a secondary heat exchanger case 6a, an exhaust collecting cylinder 7, a silencer 8, The neutralizer 9, the pipe 10, the water supply pipe 11, the hot water supply pipe 12, and the drain pipe 20 are accommodated.

  An exhaust port EP is provided on the upper surface of the housing 2. The exhaust port EP is configured to be able to exhaust the combustion gas from which sensible heat has been recovered by the primary heat exchanger 5 and latent heat has been recovered by the secondary heat exchanger 6 to the outside of the housing 2. Further, a water inlet 11a for water supply and a hot water outlet 12a for hot water supply are provided on the side surface of the housing 2.

  The burner 3 is for supplying fuel gas to the primary heat exchanger 5 and the secondary heat exchanger 6. This combustion gas is for exchanging heat between the primary heat exchanger 5 and the secondary heat exchanger 6. That is, the burner 3 generates combustion gas for performing heat exchange between the primary heat exchanger 5 and the secondary heat exchanger 6 and supplies the combustion gas to the primary heat exchanger 5 and the secondary heat exchanger 6. belongs to. In the present embodiment, the burner 3 is a reverse combustion type device in which fuel such as kerosene supplied via a fuel pipe from a fuel supply source (not shown) is sprayed downward and burned. Specifically, the burner 3 is, for example, a gun type burner.

  The burner 3 is accommodated in the burner case 3a. Therefore, the burner 3 burns fuel inside the burner case 3a to generate combustion gas. In the burner case 3a, the blower 4 is disposed above the burner case 3a, and the primary heat exchanger 5 is disposed below the burner case 3a.

  The blower 4 is for supplying combustion air to the burner 3. The blower 4 is configured to be able to supply combustion air downward from above the burner 3. Specifically, the blower 4 includes a fan, for example.

  The primary heat exchanger (heat exchanger) 5 is for recovering the heat of the combustion gas. Specifically, the primary heat exchanger 5 is for recovering sensible heat of the combustion gas supplied by the burner 3. That is, the primary heat exchanger 5 is a sensible heat recovery type heat exchanger. The primary heat exchanger 5 is accommodated in the can 5a. The primary heat exchanger 5 is arranged at a height position below the burner 3. The can body 5 a communicates with the burner case 3 a and the exhaust collecting cylinder 7.

  The secondary heat exchanger 6 is for recovering the latent heat of the combustion gas supplied by the burner 3. That is, the secondary heat exchanger 6 is a latent heat recovery type heat exchanger. The secondary heat exchanger 6 is accommodated in the secondary heat exchanger case 6a. The secondary heat exchanger case 6a communicates with the exhaust port EP.

  The exhaust collecting cylinder 7 and the silencer 8 constitute a combustion gas flow path connected in series. The exhaust collecting cylinder 7 is located downstream of the primary heat exchanger 5 in the flow direction of the combustion gas. The silencer 8 is located downstream of the exhaust collecting cylinder 7 in the flow direction of the combustion gas. The silencer 8 communicates with the secondary heat exchanger case 6a. As indicated by arrows in the figure, the combustion gas generated in the burner 3 passes through the periphery of the primary heat exchanger 5 and exchanges heat with water in the primary heat exchanger 5, and then silences through the exhaust collecting cylinder 7. Sent to vessel 8. The combustion gas sent to the silencer 8 passes through the periphery of the secondary heat exchanger 6 and exchanges heat with water in the secondary heat exchanger 6, and then is discharged out of the housing 2 from the exhaust port EP. .

  One end of the primary heat exchanger 5 and one end of the secondary heat exchanger 6 are connected to each other by a pipe 10. A water supply pipe 11 is connected to the other end of the secondary heat exchanger 6, and a hot water supply pipe 12 is connected to the other end of the primary heat exchanger 5. The primary heat exchanger 5 is arranged closer to the burner 3 than the secondary heat exchanger 6. The primary heat exchanger 5 is located upstream of the secondary heat exchanger 6 in the combustion gas flow.

  The water inlet 11 a is connected to the water supply pipe 11 and configured to be able to supply water to the secondary heat exchanger 6 and the primary heat exchanger 5 via the water supply pipe 11. The hot water outlet 12 a is connected to the hot water supply pipe 12 and is configured to be able to supply hot water heated by the secondary heat exchanger 6 and the primary heat exchanger 5. As a result, the water introduced from the water inlet 11a is heated by the combustion gas when passing through the secondary heat exchanger 6 and the primary heat exchanger 5, and is discharged from the hot water outlet 12a.

  At this time, hot water in the primary heat exchanger 5 is heated by heat exchange with the high-temperature combustion gas. The combustion gas after heat exchange in the primary heat exchanger 5 is passed to the secondary heat exchanger 6 so that the water in the secondary heat exchanger 6 is preheated. In this process, the temperature of the combustion gas is lowered to about 60 ° C., whereby moisture contained in the combustion gas is condensed and latent heat is recovered. Due to the structure in which the water vapor of the combustion gas is condensed in the secondary heat exchanger 6, condensed water (drain) is generated, so drainage of the drain is necessary.

  Drain generated by collecting the latent heat of the combustion gas in the secondary heat exchanger 6 is received on the lower surface of the secondary heat exchanger case 6a. A drain pipe 20 is connected to the lower surface of the secondary heat exchanger case 6 a and the neutralizer 9. The drain pipe 20 is configured to be able to supply drain from the secondary heat exchanger 6 to the neutralizer 9. A neutralizer 9 is disposed below the lower surface of the secondary heat exchanger case 6a. For this reason, the drain received on the lower surface of the secondary heat exchanger case 6 a flows into the neutralizer 9 through the drain pipe 20.

  The neutralizer 9 is for storing the drain generated by collecting the latent heat of the combustion gas in the secondary heat exchanger 6. Since the combustion gas contains nitrogen oxides and the like, the nitride oxides and the like dissolve in the drain and the drain becomes acidic. The neutralizer 9 is for neutralizing the acidic drain generated by recovering the latent heat of the combustion gas in the secondary heat exchanger 6. The neutralizer 9 is filled with a neutralizing agent for neutralizing acidic drain. The drain neutralized by the neutralizer 9 is discharged out of the housing 2 through a drainage channel (not shown).

  With reference to FIGS. 2-7, the structure of the primary heat exchanger 5 and the can 5a is demonstrated concretely. With reference to FIG. 2 and FIG. 3, the primary heat exchanger 5 is accommodated in the can body 5a, and is arrange | positioned in the lower part in the can body 5a. The primary heat exchanger 5 includes a plurality of fins 51, heat transfer tubes 52, and a body plate 53. The plurality of fins 51 have a plurality of through holes H. The plurality of fins 51 are stacked and spaced from each other. The plurality of through holes H of the plurality of fins 51 are arranged so as to overlap in the direction in which the plurality of fins 51 are stacked. The fluid to be heated is caused to flow through the gaps between the plurality of fins 51. The plurality of through holes H are arranged in two stages in a second direction D2 that intersects the first direction D1. The through hole H is a concept including not only a “open hole” but also a “burring hole”.

  A heat transfer tube 52 is inserted into each of the plurality of through holes H. One end E1 of the heat transfer tube 52 is connected to the pipe 10. The other end E <b> 2 of the heat transfer tube 52 is connected to the hot water supply pipe 12. The hot water supply pipe 12 is arranged in a spiral shape so as to surround the outer periphery of the can body 5a. The body plate 53 accommodates a plurality of fins 51 and heat transfer tubes 52 therein.

  3 to 5, the heat transfer tube 52 passes through the plurality of through holes H of each of the plurality of fins 51. 4 and 5, two fins 51 positioned at both ends in the stacking direction are shown as a plurality of fins 51 for the sake of simplicity and convenience of explanation.

  The heat transfer tube 52 includes a plurality of straight portions (in-case piping) 52a having a portion located inside the trunk plate 53 and a plurality of straight portions (in-case piping) 52a connected to each other outside the trunk plate 53. And a bent portion (connecting pipe) 52b.

  The plurality of linear portions 52a are arranged at intervals. The plurality of bent portions (communication portions) 52b connect one end of any of the plurality of straight portions 52a and the other end of any of the plurality of straight portions 52a. The plurality of bent portions 52b are configured in a U shape so as to connect the adjacent straight portions 52a.

  The heat transfer tube 52 is configured such that a plurality of straight portions 52a and a plurality of bent portions 52b are connected to one to meander. That is, the heat transfer tube 52 is configured to reciprocate in the direction in which the plurality of fins 51 are stacked.

  5 to 7, each of the plurality of fins 51 has a main surface S. The plurality of through holes H are arranged in the main surface S along the first direction D1. The plurality of through holes H include even-numbered first-stage through holes H1 and even-numbered second-stage through holes H2. The even-numbered first-stage through holes H1 are arranged side by side in the first direction D1. The even-numbered second-stage through holes H2 are arranged side by side in the first direction D1. The even-numbered second-stage through holes H2 are arranged at intervals in a second direction D2 that intersects the first direction D1 with the even-numbered first-stage through holes H1.

  That is, the first stage constituted by the even-numbered first-stage through holes H1 and the second stage constituted by the even-numbered second-stage through holes H2 are arranged in parallel to each other. Further, the even-numbered first-stage through holes H1 form a first row arranged in a straight line along the first direction D1. The even-numbered second-stage through holes H2 are arranged in parallel to the first row, and constitute a second row arranged in a straight line along the first direction D1.

  The even-numbered first-stage through holes H1 are disposed upstream of the even-numbered second-stage through holes H2 in the second direction D2 in the combustion gas flow direction indicated by arrows in FIG. The number of even-numbered first-stage through holes H1 is larger than the number of even-numbered second-stage through holes H2. In the present embodiment, even-numbered first-stage through holes H1 include, for example, six first-stage through holes H1, and even-numbered second-stage through holes H2 include, for example, four second-stage through holes H1. The through hole H2 is included.

  The even numbered first stage through holes H1 and the even numbered second stage through holes H2 are arranged in a staggered arrangement. That is, each of the even-numbered second-stage through holes H2 is arranged so as to be shifted from each of the even-numbered first-stage through holes H1 in the first direction D1. In the present embodiment, each of the even-numbered second-stage through holes H2 is an even-numbered first-stage through hole facing the second direction D2 (arranged along the second direction D2). They are arranged so as to be shifted outward from each of H1 in the first direction D1.

  Each of the even-numbered first-stage through holes H1 arranged at both ends in the first direction D1 is first than each of the even-numbered second-stage through holes H2 arranged at both ends in the first direction D1. In the direction D1, respectively. That is, in the first direction D1, the first-stage through hole H1 at one end is disposed outside the second-stage through hole H2 at one end, and the first-stage through hole H1 at the other end is It arrange | positions outside the 2nd step | paragraph through-hole H2 of the other end.

  The pitch P1 of the even-numbered first-stage through holes H1 is a distance between the center points C of the first-stage through holes H1 adjacent to each other with an interval in the first direction D1. The distances between the center points C of the adjacent first-stage through holes H1 are all equal. The pitch P2 of the even-numbered second stage through holes H2 is a distance between the center points C of the second stage through holes H2 adjacent to each other with an interval in the second direction D2. The distances between the center points C of the adjacent second-stage through holes H2 are all equal. The pitch P2 of the even numbered second stage through holes H2 is larger than the pitch P1 of the even numbered first stage through holes H1.

  As shown in FIG. 5, the heat transfer tube 52 is continuously passed through any one of the even-numbered first-stage through holes H1 and any one of the even-numbered second-stage through holes H2. Specifically, the heat transfer tube 52 communicates with the first-stage through hole H1 and the second-stage through hole H2 shown in the upper left part in FIG. As shown in FIG. 6, the distance L between any one of the even-numbered first-stage through holes H1 through which the heat transfer tube 52 passes and the even-numbered second-stage through-hole H2 is an even-numbered first stage. It is equal to either the pitch P1 of the eye through holes H1 or the pitch P2 of the even numbered second stage through holes H2. Note that the even-numbered first-stage through holes H1 and the even-numbered second-stage through holes H2 are both configured in a perfect circle, and their diameters are equal to each other.

  As shown in FIG. 6, the even-numbered first-stage through holes H1 and even-numbered second-stage through holes H2 have the centers of the plurality of fins 51 in the first direction D1 in the second direction D2. They are arranged line-symmetrically with respect to the passing symmetry axis A. In the present embodiment, three first-stage through holes H1 and two second-stage through holes H2 are arranged on both sides of the symmetry axis A, respectively.

  As shown in FIGS. 6 and 7, at least one of the plurality of fins 51 includes a cut and raised slit 51a. The cut and raised slit 51a protrudes from the main surface S. The cut and raised slit 51a extends in the first direction D1. Thereby, the cut-and-raised slit 51a has a tunnel-shaped hole SH extending in the second direction D2. That is, the tunnel-like hole SH of the cut and raised slit 51a penetrates along the second direction D2. The cut-and-raised slit 51a is disposed in a region adjacent to at least one of the plurality of second-stage through holes H2 in the first direction D1. In the present embodiment, the cut-and-raised slits 51a are arranged in regions on both sides of each of the plurality of second-stage through holes H2 in the first direction D1.

  In the present embodiment, each of the plurality of fins 51 includes a cut-and-raised slit 51a. Each of the plurality of fins 51 includes a plurality of cut and raised slits 51a. Each cut-and-raised slit 51a includes a first cut-and-raised slit portion 51a1, a second cut-and-raised slit portion 51a2, and a third cut-and-raised slit portion 51a3 arranged in order along the second direction D2. The first cut and raised slit portion 51a1, the second cut and raised slit portion 51a2, and the third cut and raised slit portion 51a3 are arranged in a straight line at intervals in the second direction D2.

  At least one of the plurality of fins 51 includes a cut-and-raised wall portion 51b. The cut and raised wall portion 51b protrudes from the main surface S. The cut-and-raised wall portion 51b is configured by cutting and raising a part of the fin 51 to the main surface side. The cut-and-raised wall portion 51b extends in the first direction D1.

  The cut-and-raised wall portion 51b is disposed on the opposite side of the even-numbered first-stage through holes H1 with respect to the even-numbered second-stage through holes H2 in the second direction D2. That is, the cut-and-raised wall portion 51b is disposed downstream of the even-numbered second-stage through holes in the combustion gas flow direction. The cut-and-raised wall portion 51b is arranged so as to be shifted in the first direction D1 from at least one of the even-numbered second-stage through holes H2. The cut-and-raised wall portion 51b is arranged so as not to overlap each of the even-numbered second-stage through holes H2 in the second direction D2. In the present embodiment, each of the plurality of fins 51 includes a cut-and-raised wall portion 51b. Each of the plurality of fins 51 includes a plurality of cut and raised wall portions 51b. The plurality of raised walls 51b are arranged in a straight line along the first direction D1.

  At least one of the plurality of fins 51 includes a convex portion 51c. The convex portion 51c protrudes from the main surface S. The convex part 51c is configured in a truncated cone shape. The convex portion 51c is disposed on the even-numbered first-stage through hole side with respect to the even-numbered second-stage through-hole H2 in the second direction D2. That is, the convex portion 51c is disposed on the upstream side of the second stage through hole H2 in the flow direction of the combustion gas. The convex portion 51c is arranged so as to be shifted in the first direction D1 from at least one of the even-numbered first-stage through holes H1. In the present embodiment, each of the plurality of fins 51 includes a convex portion 51c. Further, each of the plurality of fins 51 includes a plurality of convex portions 51c. The plurality of convex portions 51c are arranged in a straight line along the first direction D1.

Next, operation | movement of the combustion apparatus 1 of this Embodiment is demonstrated.
Referring to FIG. 1, when the operation switch is turned on and a predetermined amount of water is caused to flow through water supply pipe 11, the fan of blower 4 starts rotating, burner 3 is ignited, and downward from burner 3. Combustion gas is sent out. Referring to FIG. 6, the delivered combustion gas flows in the can body 5 a where the primary heat exchanger 5 is disposed, and then flows in the exhaust collection cylinder 7 through the opening 7 a of the exhaust collection cylinder 7.

  The opening 7a of the exhaust collecting cylinder 7 is provided at the center of the upper surface of the exhaust collecting cylinder 7, and is formed in a rectangular shape when viewed from the direction intersecting the upper surface. An exhaust rectifying plate 7b is connected to the rectangular four sides of the opening 7a. The exhaust rectifying plate 7b extends from the opening 7a toward the inside of the exhaust rectifying plate 7b. The exhaust flow straightening plate 7b is disposed on the inner end side of the center of each of the cut and raised slits 51a disposed at both ends in the first direction D1. Therefore, the combustion gas is collected at the center of the opening 7a by the exhaust rectifying plate 7b. Referring to FIG. 1, the combustion gas flowing in the exhaust collecting cylinder 7 flows in the silencer 8, then flows in the secondary heat exchanger case 6 a, and then is exhausted outside from the exhaust port EP. .

  On the other hand, the water sent from the water supply pipe 11 flows through the secondary heat exchanger 6. While flowing in the secondary heat exchanger 6, water is preheated by the combustion gas (latent heat). Next, the preheated water is sent to the primary heat exchanger 5 through the pipe 10. 2 and 6, the preheated water sent to the primary heat exchanger 5 passes through the trunk pipe and then passes through the upper heat transfer tube 52 (the heat transfer tube passing through the first-stage through hole H1). 52), and then flows through the lower heat transfer tube 52 (the heat transfer tube 52 passing through the second-stage through hole H2). While the preheated water flows through the heat transfer tube 52, heat is generated between the combustion gas (sensible heat) flowing through the gaps between the plurality of fins 51 and the water in the heat transfer tube 52 as indicated by arrows in FIG. Exchange is performed and the preheated water is heated to a predetermined temperature. Hot water heated to a predetermined temperature is sent out through the hot water supply pipe 12. Thus, hot water having a predetermined temperature can be supplied.

Next, the effect of this Embodiment is demonstrated.
Since the temperature of the combustion gas is higher on the upstream side in the flow direction of the combustion gas than on the downstream side, it is possible to transfer more heat quantity of the combustion gas to the heat transfer tube than on the downstream side. According to the primary heat exchanger 5 of the present embodiment, the even-numbered first-stage through holes H1 are upstream in the combustion gas flow direction in the second direction D2 than the even-numbered second-stage through holes H2. Is arranged. The number of even-numbered first-stage through holes H1 is larger than the number of even-numbered second-stage through holes H2. For this reason, the amount of heat of the combustion gas that is transmitted to the heat transfer tube 52 that passes through the even-numbered second through holes H2 on the upstream side in the flow direction of the combustion gas increases. For this reason, the efficiency with which the calorie | heat amount of combustion gas is transmitted to the heat exchanger tube 52 can be improved.

  In addition, since the plurality of through holes H include an even number of first stage through holes H1 and an even number of second stage through holes H2, one end E1 of the heat transfer tube 52 passing through the plurality of through holes H. And the other end E2 can be arrange | positioned at the main surface S side. That is, the one end E1 and the other end E2 of the heat transfer tube 52 passing through the plurality of through holes H can be arranged on the same side with respect to the plurality of fins 51. Therefore, since the pipe 10 and the hot water supply pipe 12 can be connected to the heat transfer pipe 52 from the same side, a pipe for aligning the one end E1 and the other end E2 of the heat transfer pipe 52 on the same side is not necessary, so that the connection is easy. can do.

  Further, each of the even-numbered second-stage through holes H2 is arranged so as to be shifted from each of the even-numbered first-stage through holes H1 in the first direction D1. For this reason, it is possible to make the combustion gas easily flow around the heat transfer tubes 52 that pass through each of the even-numbered second-stage through holes H2. Therefore, the heat quantity of the combustion gas can be efficiently transmitted to the heat transfer tubes 52 that pass through each of the even-numbered second-stage through holes H2.

  As described above, in the primary heat exchanger 5 of the present embodiment, since the heat exchange efficiency can be improved, the plurality of fins 51 can be reduced in size. Therefore, the primary heat exchanger 5 can be reduced in size.

  In order to obtain a predetermined heat receiving amount, the heat receiving area and the number of the heat transfer tubes 52 passing through the plurality of through holes H are generally within a certain range, but the lateral width of the primary heat exchanger 5 is It is common to have some constraints on dimensions. Here, for example, assuming that the width of the primary heat exchanger 5 (≈the width of the fin) is constant and the number of heat transfer tubes 52 passing through the plurality of through holes H is 10 in total in the upper and lower stages, the upper 7 and the lower 3 In this case, the ventilation area becomes small, and the arrangement itself is impossible, or it becomes difficult to provide the cut-and-raised wall portion 51b. On the other hand, in the case of the upper six and the lower four as in the present embodiment, there is no restriction on them, so that the degree of freedom in design can be increased.

  In the primary heat exchanger 5 of the present embodiment, the pitch P2 of the even-numbered second-stage through holes H2 is larger than the pitch P1 of the even-numbered first-stage through holes H1. For this reason, each of the even-numbered second-stage through holes H2 can be shifted from each of the even-numbered first-stage through holes H1 in the first direction D1. In addition, each of the even-numbered first-stage through holes H1 arranged at both ends in the first direction D1 is more than each of the even-numbered second-stage through holes H2 arranged at both ends in the first direction D1. They are respectively arranged outside in the first direction D1. For this reason, it is possible to make the combustion gas easily flow outside each of the even-numbered second-stage through holes H2 arranged at both ends in the first direction D1. Thereby, the efficiency with which the calorie | heat amount of combustion gas is transmitted to the heat exchanger tube 52 which passes the 2nd step | paragraph through-hole H2 of an even number can be improved.

  In the primary heat exchanger 5 of the present embodiment, the distance L between any of the even-numbered first-stage through holes H1 through which the heat transfer tubes 52 continuously pass and any of the even-numbered second-stage through holes H2 is: It is equal to either the pitch P1 of the even-numbered first-stage through holes H1 or the pitch P2 of the even-numbered second-stage through holes H2. For this reason, the bending part (connection pipe) 52b which connects the heat transfer pipes 52 passing through the adjacent first stage through holes H1 among the even numbered first stage through holes H1 and the even number second stage through holes H2 are provided. One of the bent portions (connection pipes) 52b that connect the heat transfer tubes 52 that pass through the adjacent second-stage through holes H2 and one of the even-numbered first-stage through holes H1 through which the heat transfer tubes 52 pass continuously. The bent portion (connecting tube) 52b of the heat transfer tube 52 that continuously passes through any of the even-numbered second-stage through holes H2 can have the same shape. Thereby, the productivity of the primary heat exchanger 5 can be improved.

  In the primary heat exchanger 5 of the present embodiment, the even-numbered first-stage through holes H1 and the even-numbered second-stage through holes H2 are the centers of the plurality of fins 51 in the first direction D1. They are arranged in line symmetry with respect to the symmetry axis A passing in the second direction D2. Therefore, the combustion gas can be brought into contact with the heat transfer tubes 52 that pass through the even-numbered first-stage through holes H1 and the even-numbered second-stage through holes H2 that are arranged symmetrically with respect to the symmetry axis A. . Therefore, the heat amount of the combustion gas can be transmitted to the heat transfer tube 52 evenly with respect to the symmetry axis A. Thereby, the efficiency with which the calorie | heat amount of combustion gas is transmitted to the heat exchanger tube 52 can be improved.

  In the primary heat exchanger 5 of the present embodiment, at least one of the plurality of fins 51 includes a cut and raised slit 51a. For this reason, the flow of the combustion gas is divided into the combustion gas flowing in the tunnel-shaped hole SH of the cut and raised slit 51a and the combustion gas flowing outside the tunnel-shaped hole SH. Thereby, since the turbulent flow can be generated in the flow of the combustion gas, the efficiency in which the heat amount of the combustion gas is transmitted to the heat transfer tube 52 passing through at least one of the plurality of second-stage through holes H2 is improved. Can do.

  In addition, since the plurality of first cut and raised slit portions 51a1, second cut and raised slit portions 51a2 and third cut and raised slit portions 51a3 are arranged in the second direction D2, the generation of turbulent flow of combustion gas is promoted. can do.

  In the primary heat exchanger 5 of the present embodiment, at least one of the plurality of fins 51 includes a cut and raised wall portion 51b. For this reason, the flow of the combustion gas flowing in the second direction D2 is cut and raised at the downstream side in the flow direction of the combustion gas from the even-numbered second-stage through holes H2 and changed to the first direction D1 by the wall portion 51b. Can do. Thereby, the efficiency with which the heat quantity of the combustion gas is transmitted to the heat transfer tube 52 passing through at least one of the even-numbered second stage through holes H2 can be improved.

  In the primary heat exchanger 5 of the present embodiment, at least one of the plurality of fins 51 includes a convex portion 51c. For this reason, the flow of combustion gas can be changed by the convex part 51c. Thereby, since a turbulent flow can be generated in the flow of the combustion gas flowing downstream through the periphery of the heat transfer tube 52 passing through at least any one of the even-numbered first-stage through holes H1, the heat amount of the combustion gas is plural. It is possible to improve the efficiency of transmission to the heat transfer tube 52 that passes through at least one of the second-stage through holes H2.

  The combustion apparatus 1 according to the present embodiment includes the primary heat exchanger 5 and a burner 3 for supplying combustion gas to the primary heat exchanger 5. Therefore, according to the combustion apparatus 1 of the present embodiment, the efficiency with which the amount of heat of the combustion gas supplied from the burner 3 is transmitted to the heat transfer tube 52 of the primary heat exchanger 5 can be improved.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Combustion device, 2 housing | casing, 3 burner, 4 air blower, 5 primary heat exchanger, 5a can, 6 secondary heat exchanger, 7 exhaust collecting cylinder, 8 silencer, 9 neutralizer, 10 piping, 11 water supply Piping, 12 Hot-water supply piping, 20 Drain piping, 51 Multiple fins, 51a Cut-and-raised slit, 51b Cut-and-raised wall portion, 51c Convex portion, 52 Heat transfer tube, 52a Linear portion, 52b Bending portion, 53 Body plate, A Symmetry axis, D1 first direction, D2 second direction, EP exhaust port, H through hole, H1 first stage through hole, H2 second stage through hole, L distance, P1, P2 pitch, S main surface, SH hole .

Claims (8)

A heat exchanger for recovering the heat of the combustion gas,
A plurality of fins each having a main surface and a plurality of through-holes arranged side by side along the first direction on the main surface, and being stacked and spaced from each other;
A heat transfer tube passing through the plurality of through holes of each of the plurality of fins,
The plurality of through-holes through which the heat transfer tubes pass are arranged with the even-numbered first-stage through-holes arranged side by side in the first direction and the even-numbered first through-holes arranged in the first direction. The step through holes include an even number of second step through holes arranged at intervals in a second direction intersecting the first direction,
The even-numbered first-stage through-holes are disposed upstream of the even-numbered second-stage through-holes in the second direction with respect to the flow direction of the combustion gas.
The number of the even numbered first stage through holes is larger than the number of the even numbered second stage through holes,
Each of the even-numbered second-stage through-holes is arranged to be shifted from the even-numbered first-stage through-holes in the first direction. The pitch of the even numbered second stage through holes is larger than the pitch of the even numbered first stage through holes,
Each of the even numbered first-stage through holes disposed at both ends in the first direction is more than each of the even numbered second-stage through holes disposed at both ends in the first direction. The heat exchanger according to claim 1, wherein the heat exchanger is disposed outside in the direction of 1.   The distance between any one of the even-numbered first-stage through holes and the even-numbered second-stage through-hole through which the heat transfer tube continuously passes is the pitch of the even-numbered first-stage through-holes and the The heat exchanger according to claim 2, which is equal to one of the pitches of even numbered second-stage through holes.   The even-numbered first-stage through holes and the even-numbered second-stage through holes are lines with respect to an axis of symmetry passing through the center of each of the plurality of fins in the first direction in the second direction. The heat exchanger according to any one of claims 1 to 3, which is arranged symmetrically. At least one of the plurality of fins includes a cut-and-raised slit having a tunnel-like hole protruding from the main surface and extending in the second direction,
5. The heat exchange according to claim 1, wherein the cut and raised slit is disposed in a region adjacent in the first direction of at least one of the plurality of second-stage through holes. vessel. At least one of the plurality of fins includes a cut-and-raised wall portion protruding from the main surface and extending in the first direction;
The cut-and-raised wall portion is disposed on the opposite side of the even-numbered first-stage through hole with respect to the even-numbered second-stage through hole in the second direction, and the even-numbered second-stage through hole The heat exchanger according to any one of claims 1 to 5, wherein the heat exchanger is arranged so as to be shifted from at least one of the holes in the first direction. At least one of the plurality of fins includes a protrusion protruding from the main surface,
The convex portion is arranged on the even-numbered first-stage through hole side with respect to the even-numbered second-stage through hole in the second direction, and at least one of the even-numbered first-stage through holes. The heat exchanger according to claim 1, wherein the heat exchanger is disposed so as to be shifted in the first direction. The heat exchanger according to any one of claims 1 to 7,
A combustion apparatus comprising a burner for supplying combustion gas to the heat exchanger.